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llvm-project/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp

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//===-- PPCISelDAGToDAG.cpp - PPC --pattern matching inst selector --------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines a pattern matching instruction selector for PowerPC,
// converting from a legalized dag to a PPC dag.
//
//===----------------------------------------------------------------------===//
#include "MCTargetDesc/PPCMCTargetDesc.h"
#include "MCTargetDesc/PPCPredicates.h"
#include "PPC.h"
#include "PPCISelLowering.h"
#include "PPCMachineFunctionInfo.h"
#include "PPCSubtarget.h"
#include "PPCTargetMachine.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/BranchProbabilityInfo.h"
#include "llvm/CodeGen/FunctionLoweringInfo.h"
#include "llvm/CodeGen/ISDOpcodes.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGISel.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/KnownBits.h"
#include "llvm/Support/MachineValueType.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <iterator>
#include <limits>
#include <memory>
#include <new>
#include <tuple>
#include <utility>
using namespace llvm;
#define DEBUG_TYPE "ppc-codegen"
STATISTIC(NumSextSetcc,
"Number of (sext(setcc)) nodes expanded into GPR sequence.");
STATISTIC(NumZextSetcc,
"Number of (zext(setcc)) nodes expanded into GPR sequence.");
STATISTIC(SignExtensionsAdded,
"Number of sign extensions for compare inputs added.");
STATISTIC(ZeroExtensionsAdded,
"Number of zero extensions for compare inputs added.");
STATISTIC(NumLogicOpsOnComparison,
"Number of logical ops on i1 values calculated in GPR.");
STATISTIC(OmittedForNonExtendUses,
"Number of compares not eliminated as they have non-extending uses.");
STATISTIC(NumP9Setb,
"Number of compares lowered to setb.");
// FIXME: Remove this once the bug has been fixed!
cl::opt<bool> ANDIGlueBug("expose-ppc-andi-glue-bug",
cl::desc("expose the ANDI glue bug on PPC"), cl::Hidden);
static cl::opt<bool>
UseBitPermRewriter("ppc-use-bit-perm-rewriter", cl::init(true),
cl::desc("use aggressive ppc isel for bit permutations"),
cl::Hidden);
static cl::opt<bool> BPermRewriterNoMasking(
"ppc-bit-perm-rewriter-stress-rotates",
cl::desc("stress rotate selection in aggressive ppc isel for "
"bit permutations"),
cl::Hidden);
static cl::opt<bool> EnableBranchHint(
"ppc-use-branch-hint", cl::init(true),
cl::desc("Enable static hinting of branches on ppc"),
cl::Hidden);
static cl::opt<bool> EnableTLSOpt(
"ppc-tls-opt", cl::init(true),
cl::desc("Enable tls optimization peephole"),
cl::Hidden);
enum ICmpInGPRType { ICGPR_All, ICGPR_None, ICGPR_I32, ICGPR_I64,
ICGPR_NonExtIn, ICGPR_Zext, ICGPR_Sext, ICGPR_ZextI32,
ICGPR_SextI32, ICGPR_ZextI64, ICGPR_SextI64 };
static cl::opt<ICmpInGPRType> CmpInGPR(
"ppc-gpr-icmps", cl::Hidden, cl::init(ICGPR_All),
cl::desc("Specify the types of comparisons to emit GPR-only code for."),
cl::values(clEnumValN(ICGPR_None, "none", "Do not modify integer comparisons."),
clEnumValN(ICGPR_All, "all", "All possible int comparisons in GPRs."),
clEnumValN(ICGPR_I32, "i32", "Only i32 comparisons in GPRs."),
clEnumValN(ICGPR_I64, "i64", "Only i64 comparisons in GPRs."),
clEnumValN(ICGPR_NonExtIn, "nonextin",
"Only comparisons where inputs don't need [sz]ext."),
clEnumValN(ICGPR_Zext, "zext", "Only comparisons with zext result."),
clEnumValN(ICGPR_ZextI32, "zexti32",
"Only i32 comparisons with zext result."),
clEnumValN(ICGPR_ZextI64, "zexti64",
"Only i64 comparisons with zext result."),
clEnumValN(ICGPR_Sext, "sext", "Only comparisons with sext result."),
clEnumValN(ICGPR_SextI32, "sexti32",
"Only i32 comparisons with sext result."),
clEnumValN(ICGPR_SextI64, "sexti64",
"Only i64 comparisons with sext result.")));
namespace {
//===--------------------------------------------------------------------===//
/// PPCDAGToDAGISel - PPC specific code to select PPC machine
/// instructions for SelectionDAG operations.
///
class PPCDAGToDAGISel : public SelectionDAGISel {
const PPCTargetMachine &TM;
const PPCSubtarget *PPCSubTarget;
const PPCTargetLowering *PPCLowering;
unsigned GlobalBaseReg;
public:
explicit PPCDAGToDAGISel(PPCTargetMachine &tm, CodeGenOpt::Level OptLevel)
: SelectionDAGISel(tm, OptLevel), TM(tm) {}
bool runOnMachineFunction(MachineFunction &MF) override {
// Make sure we re-emit a set of the global base reg if necessary
GlobalBaseReg = 0;
PPCSubTarget = &MF.getSubtarget<PPCSubtarget>();
PPCLowering = PPCSubTarget->getTargetLowering();
SelectionDAGISel::runOnMachineFunction(MF);
if (!PPCSubTarget->isSVR4ABI())
InsertVRSaveCode(MF);
return true;
}
void PreprocessISelDAG() override;
void PostprocessISelDAG() override;
/// getI16Imm - Return a target constant with the specified value, of type
/// i16.
inline SDValue getI16Imm(unsigned Imm, const SDLoc &dl) {
return CurDAG->getTargetConstant(Imm, dl, MVT::i16);
}
/// getI32Imm - Return a target constant with the specified value, of type
/// i32.
inline SDValue getI32Imm(unsigned Imm, const SDLoc &dl) {
return CurDAG->getTargetConstant(Imm, dl, MVT::i32);
}
/// getI64Imm - Return a target constant with the specified value, of type
/// i64.
inline SDValue getI64Imm(uint64_t Imm, const SDLoc &dl) {
return CurDAG->getTargetConstant(Imm, dl, MVT::i64);
}
/// getSmallIPtrImm - Return a target constant of pointer type.
inline SDValue getSmallIPtrImm(unsigned Imm, const SDLoc &dl) {
return CurDAG->getTargetConstant(
Imm, dl, PPCLowering->getPointerTy(CurDAG->getDataLayout()));
}
/// isRotateAndMask - Returns true if Mask and Shift can be folded into a
/// rotate and mask opcode and mask operation.
static bool isRotateAndMask(SDNode *N, unsigned Mask, bool isShiftMask,
unsigned &SH, unsigned &MB, unsigned &ME);
/// getGlobalBaseReg - insert code into the entry mbb to materialize the PIC
/// base register. Return the virtual register that holds this value.
SDNode *getGlobalBaseReg();
void selectFrameIndex(SDNode *SN, SDNode *N, unsigned Offset = 0);
// Select - Convert the specified operand from a target-independent to a
// target-specific node if it hasn't already been changed.
void Select(SDNode *N) override;
bool tryBitfieldInsert(SDNode *N);
bool tryBitPermutation(SDNode *N);
bool tryIntCompareInGPR(SDNode *N);
// tryTLSXFormLoad - Convert an ISD::LOAD fed by a PPCISD::ADD_TLS into
// an X-Form load instruction with the offset being a relocation coming from
// the PPCISD::ADD_TLS.
bool tryTLSXFormLoad(LoadSDNode *N);
// tryTLSXFormStore - Convert an ISD::STORE fed by a PPCISD::ADD_TLS into
// an X-Form store instruction with the offset being a relocation coming from
// the PPCISD::ADD_TLS.
bool tryTLSXFormStore(StoreSDNode *N);
/// SelectCC - Select a comparison of the specified values with the
/// specified condition code, returning the CR# of the expression.
SDValue SelectCC(SDValue LHS, SDValue RHS, ISD::CondCode CC,
const SDLoc &dl);
/// SelectAddrImmOffs - Return true if the operand is valid for a preinc
/// immediate field. Note that the operand at this point is already the
/// result of a prior SelectAddressRegImm call.
bool SelectAddrImmOffs(SDValue N, SDValue &Out) const {
if (N.getOpcode() == ISD::TargetConstant ||
N.getOpcode() == ISD::TargetGlobalAddress) {
Out = N;
return true;
}
return false;
}
/// SelectAddrIdx - Given the specified address, check to see if it can be
/// represented as an indexed [r+r] operation.
/// This is for xform instructions whose associated displacement form is D.
/// The last parameter \p 0 means associated D form has no requirment for 16
/// bit signed displacement.
/// Returns false if it can be represented by [r+imm], which are preferred.
bool SelectAddrIdx(SDValue N, SDValue &Base, SDValue &Index) {
return PPCLowering->SelectAddressRegReg(N, Base, Index, *CurDAG, 0);
}
/// SelectAddrIdx4 - Given the specified address, check to see if it can be
/// represented as an indexed [r+r] operation.
/// This is for xform instructions whose associated displacement form is DS.
/// The last parameter \p 4 means associated DS form 16 bit signed
/// displacement must be a multiple of 4.
/// Returns false if it can be represented by [r+imm], which are preferred.
bool SelectAddrIdxX4(SDValue N, SDValue &Base, SDValue &Index) {
return PPCLowering->SelectAddressRegReg(N, Base, Index, *CurDAG, 4);
}
/// SelectAddrIdx16 - Given the specified address, check to see if it can be
/// represented as an indexed [r+r] operation.
/// This is for xform instructions whose associated displacement form is DQ.
/// The last parameter \p 16 means associated DQ form 16 bit signed
/// displacement must be a multiple of 16.
/// Returns false if it can be represented by [r+imm], which are preferred.
bool SelectAddrIdxX16(SDValue N, SDValue &Base, SDValue &Index) {
return PPCLowering->SelectAddressRegReg(N, Base, Index, *CurDAG, 16);
}
/// SelectAddrIdxOnly - Given the specified address, force it to be
/// represented as an indexed [r+r] operation.
bool SelectAddrIdxOnly(SDValue N, SDValue &Base, SDValue &Index) {
return PPCLowering->SelectAddressRegRegOnly(N, Base, Index, *CurDAG);
}
/// SelectAddrImm - Returns true if the address N can be represented by
/// a base register plus a signed 16-bit displacement [r+imm].
/// The last parameter \p 0 means D form has no requirment for 16 bit signed
/// displacement.
bool SelectAddrImm(SDValue N, SDValue &Disp,
SDValue &Base) {
return PPCLowering->SelectAddressRegImm(N, Disp, Base, *CurDAG, 0);
}
/// SelectAddrImmX4 - Returns true if the address N can be represented by
/// a base register plus a signed 16-bit displacement that is a multiple of
/// 4 (last parameter). Suitable for use by STD and friends.
bool SelectAddrImmX4(SDValue N, SDValue &Disp, SDValue &Base) {
return PPCLowering->SelectAddressRegImm(N, Disp, Base, *CurDAG, 4);
}
/// SelectAddrImmX16 - Returns true if the address N can be represented by
/// a base register plus a signed 16-bit displacement that is a multiple of
/// 16(last parameter). Suitable for use by STXV and friends.
bool SelectAddrImmX16(SDValue N, SDValue &Disp, SDValue &Base) {
return PPCLowering->SelectAddressRegImm(N, Disp, Base, *CurDAG, 16);
}
// Select an address into a single register.
bool SelectAddr(SDValue N, SDValue &Base) {
Base = N;
return true;
}
/// SelectInlineAsmMemoryOperand - Implement addressing mode selection for
/// inline asm expressions. It is always correct to compute the value into
/// a register. The case of adding a (possibly relocatable) constant to a
/// register can be improved, but it is wrong to substitute Reg+Reg for
/// Reg in an asm, because the load or store opcode would have to change.
bool SelectInlineAsmMemoryOperand(const SDValue &Op,
unsigned ConstraintID,
std::vector<SDValue> &OutOps) override {
switch(ConstraintID) {
default:
errs() << "ConstraintID: " << ConstraintID << "\n";
llvm_unreachable("Unexpected asm memory constraint");
case InlineAsm::Constraint_es:
case InlineAsm::Constraint_i:
case InlineAsm::Constraint_m:
case InlineAsm::Constraint_o:
case InlineAsm::Constraint_Q:
case InlineAsm::Constraint_Z:
case InlineAsm::Constraint_Zy:
// We need to make sure that this one operand does not end up in r0
// (because we might end up lowering this as 0(%op)).
const TargetRegisterInfo *TRI = PPCSubTarget->getRegisterInfo();
const TargetRegisterClass *TRC = TRI->getPointerRegClass(*MF, /*Kind=*/1);
SDLoc dl(Op);
SDValue RC = CurDAG->getTargetConstant(TRC->getID(), dl, MVT::i32);
SDValue NewOp =
SDValue(CurDAG->getMachineNode(TargetOpcode::COPY_TO_REGCLASS,
dl, Op.getValueType(),
Op, RC), 0);
OutOps.push_back(NewOp);
return false;
}
return true;
}
void InsertVRSaveCode(MachineFunction &MF);
StringRef getPassName() const override {
return "PowerPC DAG->DAG Pattern Instruction Selection";
}
// Include the pieces autogenerated from the target description.
#include "PPCGenDAGISel.inc"
private:
bool trySETCC(SDNode *N);
void PeepholePPC64();
void PeepholePPC64ZExt();
void PeepholeCROps();
SDValue combineToCMPB(SDNode *N);
void foldBoolExts(SDValue &Res, SDNode *&N);
bool AllUsersSelectZero(SDNode *N);
void SwapAllSelectUsers(SDNode *N);
bool isOffsetMultipleOf(SDNode *N, unsigned Val) const;
void transferMemOperands(SDNode *N, SDNode *Result);
};
} // end anonymous namespace
/// InsertVRSaveCode - Once the entire function has been instruction selected,
/// all virtual registers are created and all machine instructions are built,
/// check to see if we need to save/restore VRSAVE. If so, do it.
void PPCDAGToDAGISel::InsertVRSaveCode(MachineFunction &Fn) {
// Check to see if this function uses vector registers, which means we have to
// save and restore the VRSAVE register and update it with the regs we use.
//
// In this case, there will be virtual registers of vector type created
// by the scheduler. Detect them now.
bool HasVectorVReg = false;
for (unsigned i = 0, e = RegInfo->getNumVirtRegs(); i != e; ++i) {
unsigned Reg = Register::index2VirtReg(i);
if (RegInfo->getRegClass(Reg) == &PPC::VRRCRegClass) {
HasVectorVReg = true;
break;
}
}
if (!HasVectorVReg) return; // nothing to do.
// If we have a vector register, we want to emit code into the entry and exit
// blocks to save and restore the VRSAVE register. We do this here (instead
// of marking all vector instructions as clobbering VRSAVE) for two reasons:
//
// 1. This (trivially) reduces the load on the register allocator, by not
// having to represent the live range of the VRSAVE register.
// 2. This (more significantly) allows us to create a temporary virtual
// register to hold the saved VRSAVE value, allowing this temporary to be
// register allocated, instead of forcing it to be spilled to the stack.
// Create two vregs - one to hold the VRSAVE register that is live-in to the
// function and one for the value after having bits or'd into it.
Register InVRSAVE = RegInfo->createVirtualRegister(&PPC::GPRCRegClass);
Register UpdatedVRSAVE = RegInfo->createVirtualRegister(&PPC::GPRCRegClass);
const TargetInstrInfo &TII = *PPCSubTarget->getInstrInfo();
MachineBasicBlock &EntryBB = *Fn.begin();
DebugLoc dl;
// Emit the following code into the entry block:
// InVRSAVE = MFVRSAVE
// UpdatedVRSAVE = UPDATE_VRSAVE InVRSAVE
// MTVRSAVE UpdatedVRSAVE
MachineBasicBlock::iterator IP = EntryBB.begin(); // Insert Point
BuildMI(EntryBB, IP, dl, TII.get(PPC::MFVRSAVE), InVRSAVE);
BuildMI(EntryBB, IP, dl, TII.get(PPC::UPDATE_VRSAVE),
UpdatedVRSAVE).addReg(InVRSAVE);
BuildMI(EntryBB, IP, dl, TII.get(PPC::MTVRSAVE)).addReg(UpdatedVRSAVE);
// Find all return blocks, outputting a restore in each epilog.
for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) {
if (BB->isReturnBlock()) {
IP = BB->end(); --IP;
// Skip over all terminator instructions, which are part of the return
// sequence.
MachineBasicBlock::iterator I2 = IP;
while (I2 != BB->begin() && (--I2)->isTerminator())
IP = I2;
// Emit: MTVRSAVE InVRSave
BuildMI(*BB, IP, dl, TII.get(PPC::MTVRSAVE)).addReg(InVRSAVE);
}
}
}
/// getGlobalBaseReg - Output the instructions required to put the
/// base address to use for accessing globals into a register.
///
SDNode *PPCDAGToDAGISel::getGlobalBaseReg() {
if (!GlobalBaseReg) {
const TargetInstrInfo &TII = *PPCSubTarget->getInstrInfo();
// Insert the set of GlobalBaseReg into the first MBB of the function
MachineBasicBlock &FirstMBB = MF->front();
MachineBasicBlock::iterator MBBI = FirstMBB.begin();
const Module *M = MF->getFunction().getParent();
DebugLoc dl;
if (PPCLowering->getPointerTy(CurDAG->getDataLayout()) == MVT::i32) {
if (PPCSubTarget->isTargetELF()) {
GlobalBaseReg = PPC::R30;
if (!PPCSubTarget->isSecurePlt() &&
M->getPICLevel() == PICLevel::SmallPIC) {
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MoveGOTtoLR));
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR), GlobalBaseReg);
MF->getInfo<PPCFunctionInfo>()->setUsesPICBase(true);
} else {
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MovePCtoLR));
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR), GlobalBaseReg);
Register TempReg = RegInfo->createVirtualRegister(&PPC::GPRCRegClass);
BuildMI(FirstMBB, MBBI, dl,
TII.get(PPC::UpdateGBR), GlobalBaseReg)
.addReg(TempReg, RegState::Define).addReg(GlobalBaseReg);
MF->getInfo<PPCFunctionInfo>()->setUsesPICBase(true);
}
} else {
GlobalBaseReg =
RegInfo->createVirtualRegister(&PPC::GPRC_and_GPRC_NOR0RegClass);
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MovePCtoLR));
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR), GlobalBaseReg);
}
} else {
// We must ensure that this sequence is dominated by the prologue.
// FIXME: This is a bit of a big hammer since we don't get the benefits
// of shrink-wrapping whenever we emit this instruction. Considering
// this is used in any function where we emit a jump table, this may be
// a significant limitation. We should consider inserting this in the
// block where it is used and then commoning this sequence up if it
// appears in multiple places.
// Note: on ISA 3.0 cores, we can use lnia (addpcis) instead of
// MovePCtoLR8.
MF->getInfo<PPCFunctionInfo>()->setShrinkWrapDisabled(true);
GlobalBaseReg = RegInfo->createVirtualRegister(&PPC::G8RC_and_G8RC_NOX0RegClass);
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MovePCtoLR8));
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR8), GlobalBaseReg);
}
}
return CurDAG->getRegister(GlobalBaseReg,
PPCLowering->getPointerTy(CurDAG->getDataLayout()))
.getNode();
}
/// isInt32Immediate - This method tests to see if the node is a 32-bit constant
/// operand. If so Imm will receive the 32-bit value.
static bool isInt32Immediate(SDNode *N, unsigned &Imm) {
if (N->getOpcode() == ISD::Constant && N->getValueType(0) == MVT::i32) {
Imm = cast<ConstantSDNode>(N)->getZExtValue();
return true;
}
return false;
}
/// isInt64Immediate - This method tests to see if the node is a 64-bit constant
/// operand. If so Imm will receive the 64-bit value.
static bool isInt64Immediate(SDNode *N, uint64_t &Imm) {
if (N->getOpcode() == ISD::Constant && N->getValueType(0) == MVT::i64) {
Imm = cast<ConstantSDNode>(N)->getZExtValue();
return true;
}
return false;
}
// isInt32Immediate - This method tests to see if a constant operand.
// If so Imm will receive the 32 bit value.
static bool isInt32Immediate(SDValue N, unsigned &Imm) {
return isInt32Immediate(N.getNode(), Imm);
}
/// isInt64Immediate - This method tests to see if the value is a 64-bit
/// constant operand. If so Imm will receive the 64-bit value.
static bool isInt64Immediate(SDValue N, uint64_t &Imm) {
return isInt64Immediate(N.getNode(), Imm);
}
static unsigned getBranchHint(unsigned PCC, FunctionLoweringInfo *FuncInfo,
const SDValue &DestMBB) {
assert(isa<BasicBlockSDNode>(DestMBB));
if (!FuncInfo->BPI) return PPC::BR_NO_HINT;
const BasicBlock *BB = FuncInfo->MBB->getBasicBlock();
const Instruction *BBTerm = BB->getTerminator();
if (BBTerm->getNumSuccessors() != 2) return PPC::BR_NO_HINT;
const BasicBlock *TBB = BBTerm->getSuccessor(0);
const BasicBlock *FBB = BBTerm->getSuccessor(1);
auto TProb = FuncInfo->BPI->getEdgeProbability(BB, TBB);
auto FProb = FuncInfo->BPI->getEdgeProbability(BB, FBB);
// We only want to handle cases which are easy to predict at static time, e.g.
// C++ throw statement, that is very likely not taken, or calling never
// returned function, e.g. stdlib exit(). So we set Threshold to filter
// unwanted cases.
//
// Below is LLVM branch weight table, we only want to handle case 1, 2
//
// Case Taken:Nontaken Example
// 1. Unreachable 1048575:1 C++ throw, stdlib exit(),
// 2. Invoke-terminating 1:1048575
// 3. Coldblock 4:64 __builtin_expect
// 4. Loop Branch 124:4 For loop
// 5. PH/ZH/FPH 20:12
const uint32_t Threshold = 10000;
if (std::max(TProb, FProb) / Threshold < std::min(TProb, FProb))
return PPC::BR_NO_HINT;
LLVM_DEBUG(dbgs() << "Use branch hint for '" << FuncInfo->Fn->getName()
<< "::" << BB->getName() << "'\n"
<< " -> " << TBB->getName() << ": " << TProb << "\n"
<< " -> " << FBB->getName() << ": " << FProb << "\n");
const BasicBlockSDNode *BBDN = cast<BasicBlockSDNode>(DestMBB);
// If Dest BasicBlock is False-BasicBlock (FBB), swap branch probabilities,
// because we want 'TProb' stands for 'branch probability' to Dest BasicBlock
if (BBDN->getBasicBlock()->getBasicBlock() != TBB)
std::swap(TProb, FProb);
return (TProb > FProb) ? PPC::BR_TAKEN_HINT : PPC::BR_NONTAKEN_HINT;
}
// isOpcWithIntImmediate - This method tests to see if the node is a specific
// opcode and that it has a immediate integer right operand.
// If so Imm will receive the 32 bit value.
static bool isOpcWithIntImmediate(SDNode *N, unsigned Opc, unsigned& Imm) {
return N->getOpcode() == Opc
&& isInt32Immediate(N->getOperand(1).getNode(), Imm);
}
void PPCDAGToDAGISel::selectFrameIndex(SDNode *SN, SDNode *N, unsigned Offset) {
SDLoc dl(SN);
int FI = cast<FrameIndexSDNode>(N)->getIndex();
SDValue TFI = CurDAG->getTargetFrameIndex(FI, N->getValueType(0));
unsigned Opc = N->getValueType(0) == MVT::i32 ? PPC::ADDI : PPC::ADDI8;
if (SN->hasOneUse())
CurDAG->SelectNodeTo(SN, Opc, N->getValueType(0), TFI,
getSmallIPtrImm(Offset, dl));
else
ReplaceNode(SN, CurDAG->getMachineNode(Opc, dl, N->getValueType(0), TFI,
getSmallIPtrImm(Offset, dl)));
}
bool PPCDAGToDAGISel::isRotateAndMask(SDNode *N, unsigned Mask,
bool isShiftMask, unsigned &SH,
unsigned &MB, unsigned &ME) {
// Don't even go down this path for i64, since different logic will be
// necessary for rldicl/rldicr/rldimi.
if (N->getValueType(0) != MVT::i32)
return false;
unsigned Shift = 32;
unsigned Indeterminant = ~0; // bit mask marking indeterminant results
unsigned Opcode = N->getOpcode();
if (N->getNumOperands() != 2 ||
!isInt32Immediate(N->getOperand(1).getNode(), Shift) || (Shift > 31))
return false;
if (Opcode == ISD::SHL) {
// apply shift left to mask if it comes first
if (isShiftMask) Mask = Mask << Shift;
// determine which bits are made indeterminant by shift
Indeterminant = ~(0xFFFFFFFFu << Shift);
} else if (Opcode == ISD::SRL) {
// apply shift right to mask if it comes first
if (isShiftMask) Mask = Mask >> Shift;
// determine which bits are made indeterminant by shift
Indeterminant = ~(0xFFFFFFFFu >> Shift);
// adjust for the left rotate
Shift = 32 - Shift;
} else if (Opcode == ISD::ROTL) {
Indeterminant = 0;
} else {
return false;
}
// if the mask doesn't intersect any Indeterminant bits
if (Mask && !(Mask & Indeterminant)) {
SH = Shift & 31;
// make sure the mask is still a mask (wrap arounds may not be)
return isRunOfOnes(Mask, MB, ME);
}
return false;
}
bool PPCDAGToDAGISel::tryTLSXFormStore(StoreSDNode *ST) {
SDValue Base = ST->getBasePtr();
if (Base.getOpcode() != PPCISD::ADD_TLS)
return false;
SDValue Offset = ST->getOffset();
if (!Offset.isUndef())
return false;
SDLoc dl(ST);
EVT MemVT = ST->getMemoryVT();
EVT RegVT = ST->getValue().getValueType();
unsigned Opcode;
switch (MemVT.getSimpleVT().SimpleTy) {
default:
return false;
case MVT::i8: {
Opcode = (RegVT == MVT::i32) ? PPC::STBXTLS_32 : PPC::STBXTLS;
break;
}
case MVT::i16: {
Opcode = (RegVT == MVT::i32) ? PPC::STHXTLS_32 : PPC::STHXTLS;
break;
}
case MVT::i32: {
Opcode = (RegVT == MVT::i32) ? PPC::STWXTLS_32 : PPC::STWXTLS;
break;
}
case MVT::i64: {
Opcode = PPC::STDXTLS;
break;
}
}
SDValue Chain = ST->getChain();
SDVTList VTs = ST->getVTList();
SDValue Ops[] = {ST->getValue(), Base.getOperand(0), Base.getOperand(1),
Chain};
SDNode *MN = CurDAG->getMachineNode(Opcode, dl, VTs, Ops);
transferMemOperands(ST, MN);
ReplaceNode(ST, MN);
return true;
}
bool PPCDAGToDAGISel::tryTLSXFormLoad(LoadSDNode *LD) {
SDValue Base = LD->getBasePtr();
if (Base.getOpcode() != PPCISD::ADD_TLS)
return false;
SDValue Offset = LD->getOffset();
if (!Offset.isUndef())
return false;
SDLoc dl(LD);
EVT MemVT = LD->getMemoryVT();
EVT RegVT = LD->getValueType(0);
unsigned Opcode;
switch (MemVT.getSimpleVT().SimpleTy) {
default:
return false;
case MVT::i8: {
Opcode = (RegVT == MVT::i32) ? PPC::LBZXTLS_32 : PPC::LBZXTLS;
break;
}
case MVT::i16: {
Opcode = (RegVT == MVT::i32) ? PPC::LHZXTLS_32 : PPC::LHZXTLS;
break;
}
case MVT::i32: {
Opcode = (RegVT == MVT::i32) ? PPC::LWZXTLS_32 : PPC::LWZXTLS;
break;
}
case MVT::i64: {
Opcode = PPC::LDXTLS;
break;
}
}
SDValue Chain = LD->getChain();
SDVTList VTs = LD->getVTList();
SDValue Ops[] = {Base.getOperand(0), Base.getOperand(1), Chain};
SDNode *MN = CurDAG->getMachineNode(Opcode, dl, VTs, Ops);
transferMemOperands(LD, MN);
ReplaceNode(LD, MN);
return true;
}
/// Turn an or of two masked values into the rotate left word immediate then
/// mask insert (rlwimi) instruction.
bool PPCDAGToDAGISel::tryBitfieldInsert(SDNode *N) {
SDValue Op0 = N->getOperand(0);
SDValue Op1 = N->getOperand(1);
SDLoc dl(N);
KnownBits LKnown = CurDAG->computeKnownBits(Op0);
KnownBits RKnown = CurDAG->computeKnownBits(Op1);
unsigned TargetMask = LKnown.Zero.getZExtValue();
unsigned InsertMask = RKnown.Zero.getZExtValue();
if ((TargetMask | InsertMask) == 0xFFFFFFFF) {
unsigned Op0Opc = Op0.getOpcode();
unsigned Op1Opc = Op1.getOpcode();
unsigned Value, SH = 0;
TargetMask = ~TargetMask;
InsertMask = ~InsertMask;
// If the LHS has a foldable shift and the RHS does not, then swap it to the
// RHS so that we can fold the shift into the insert.
if (Op0Opc == ISD::AND && Op1Opc == ISD::AND) {
if (Op0.getOperand(0).getOpcode() == ISD::SHL ||
Op0.getOperand(0).getOpcode() == ISD::SRL) {
if (Op1.getOperand(0).getOpcode() != ISD::SHL &&
Op1.getOperand(0).getOpcode() != ISD::SRL) {
std::swap(Op0, Op1);
std::swap(Op0Opc, Op1Opc);
std::swap(TargetMask, InsertMask);
}
}
} else if (Op0Opc == ISD::SHL || Op0Opc == ISD::SRL) {
if (Op1Opc == ISD::AND && Op1.getOperand(0).getOpcode() != ISD::SHL &&
Op1.getOperand(0).getOpcode() != ISD::SRL) {
std::swap(Op0, Op1);
std::swap(Op0Opc, Op1Opc);
std::swap(TargetMask, InsertMask);
}
}
unsigned MB, ME;
if (isRunOfOnes(InsertMask, MB, ME)) {
if ((Op1Opc == ISD::SHL || Op1Opc == ISD::SRL) &&
isInt32Immediate(Op1.getOperand(1), Value)) {
Op1 = Op1.getOperand(0);
SH = (Op1Opc == ISD::SHL) ? Value : 32 - Value;
}
if (Op1Opc == ISD::AND) {
// The AND mask might not be a constant, and we need to make sure that
// if we're going to fold the masking with the insert, all bits not
// know to be zero in the mask are known to be one.
KnownBits MKnown = CurDAG->computeKnownBits(Op1.getOperand(1));
bool CanFoldMask = InsertMask == MKnown.One.getZExtValue();
unsigned SHOpc = Op1.getOperand(0).getOpcode();
if ((SHOpc == ISD::SHL || SHOpc == ISD::SRL) && CanFoldMask &&
isInt32Immediate(Op1.getOperand(0).getOperand(1), Value)) {
// Note that Value must be in range here (less than 32) because
// otherwise there would not be any bits set in InsertMask.
Op1 = Op1.getOperand(0).getOperand(0);
SH = (SHOpc == ISD::SHL) ? Value : 32 - Value;
}
}
SH &= 31;
SDValue Ops[] = { Op0, Op1, getI32Imm(SH, dl), getI32Imm(MB, dl),
getI32Imm(ME, dl) };
ReplaceNode(N, CurDAG->getMachineNode(PPC::RLWIMI, dl, MVT::i32, Ops));
return true;
}
}
return false;
}
// Predict the number of instructions that would be generated by calling
// selectI64Imm(N).
static unsigned selectI64ImmInstrCountDirect(int64_t Imm) {
// Assume no remaining bits.
unsigned Remainder = 0;
// Assume no shift required.
unsigned Shift = 0;
// If it can't be represented as a 32 bit value.
if (!isInt<32>(Imm)) {
Shift = countTrailingZeros<uint64_t>(Imm);
int64_t ImmSh = static_cast<uint64_t>(Imm) >> Shift;
// If the shifted value fits 32 bits.
if (isInt<32>(ImmSh)) {
// Go with the shifted value.
Imm = ImmSh;
} else {
// Still stuck with a 64 bit value.
Remainder = Imm;
Shift = 32;
Imm >>= 32;
}
}
// Intermediate operand.
unsigned Result = 0;
// Handle first 32 bits.
unsigned Lo = Imm & 0xFFFF;
// Simple value.
if (isInt<16>(Imm)) {
// Just the Lo bits.
++Result;
} else if (Lo) {
// Handle the Hi bits and Lo bits.
Result += 2;
} else {
// Just the Hi bits.
++Result;
}
// If no shift, we're done.
if (!Shift) return Result;
// If Hi word == Lo word,
// we can use rldimi to insert the Lo word into Hi word.
if ((unsigned)(Imm & 0xFFFFFFFF) == Remainder) {
++Result;
return Result;
}
// Shift for next step if the upper 32-bits were not zero.
if (Imm)
++Result;
// Add in the last bits as required.
if ((Remainder >> 16) & 0xFFFF)
++Result;
if (Remainder & 0xFFFF)
++Result;
return Result;
}
static uint64_t Rot64(uint64_t Imm, unsigned R) {
return (Imm << R) | (Imm >> (64 - R));
}
static unsigned selectI64ImmInstrCount(int64_t Imm) {
unsigned Count = selectI64ImmInstrCountDirect(Imm);
// If the instruction count is 1 or 2, we do not need further analysis
// since rotate + load constant requires at least 2 instructions.
if (Count <= 2)
return Count;
for (unsigned r = 1; r < 63; ++r) {
uint64_t RImm = Rot64(Imm, r);
unsigned RCount = selectI64ImmInstrCountDirect(RImm) + 1;
Count = std::min(Count, RCount);
// See comments in selectI64Imm for an explanation of the logic below.
unsigned LS = findLastSet(RImm);
if (LS != r-1)
continue;
uint64_t OnesMask = -(int64_t) (UINT64_C(1) << (LS+1));
uint64_t RImmWithOnes = RImm | OnesMask;
RCount = selectI64ImmInstrCountDirect(RImmWithOnes) + 1;
Count = std::min(Count, RCount);
}
return Count;
}
// Select a 64-bit constant. For cost-modeling purposes, selectI64ImmInstrCount
// (above) needs to be kept in sync with this function.
static SDNode *selectI64ImmDirect(SelectionDAG *CurDAG, const SDLoc &dl,
int64_t Imm) {
// Assume no remaining bits.
unsigned Remainder = 0;
// Assume no shift required.
unsigned Shift = 0;
// If it can't be represented as a 32 bit value.
if (!isInt<32>(Imm)) {
Shift = countTrailingZeros<uint64_t>(Imm);
int64_t ImmSh = static_cast<uint64_t>(Imm) >> Shift;
// If the shifted value fits 32 bits.
if (isInt<32>(ImmSh)) {
// Go with the shifted value.
Imm = ImmSh;
} else {
// Still stuck with a 64 bit value.
Remainder = Imm;
Shift = 32;
Imm >>= 32;
}
}
// Intermediate operand.
SDNode *Result;
// Handle first 32 bits.
unsigned Lo = Imm & 0xFFFF;
unsigned Hi = (Imm >> 16) & 0xFFFF;
auto getI32Imm = [CurDAG, dl](unsigned Imm) {
return CurDAG->getTargetConstant(Imm, dl, MVT::i32);
};
// Simple value.
if (isInt<16>(Imm)) {
uint64_t SextImm = SignExtend64(Lo, 16);
SDValue SDImm = CurDAG->getTargetConstant(SextImm, dl, MVT::i64);
// Just the Lo bits.
Result = CurDAG->getMachineNode(PPC::LI8, dl, MVT::i64, SDImm);
} else if (Lo) {
// Handle the Hi bits.
unsigned OpC = Hi ? PPC::LIS8 : PPC::LI8;
Result = CurDAG->getMachineNode(OpC, dl, MVT::i64, getI32Imm(Hi));
// And Lo bits.
Result = CurDAG->getMachineNode(PPC::ORI8, dl, MVT::i64,
SDValue(Result, 0), getI32Imm(Lo));
} else {
// Just the Hi bits.
Result = CurDAG->getMachineNode(PPC::LIS8, dl, MVT::i64, getI32Imm(Hi));
}
// If no shift, we're done.
if (!Shift) return Result;
// If Hi word == Lo word,
// we can use rldimi to insert the Lo word into Hi word.
if ((unsigned)(Imm & 0xFFFFFFFF) == Remainder) {
SDValue Ops[] =
{ SDValue(Result, 0), SDValue(Result, 0), getI32Imm(Shift), getI32Imm(0)};
return CurDAG->getMachineNode(PPC::RLDIMI, dl, MVT::i64, Ops);
}
// Shift for next step if the upper 32-bits were not zero.
if (Imm) {
Result = CurDAG->getMachineNode(PPC::RLDICR, dl, MVT::i64,
SDValue(Result, 0),
getI32Imm(Shift),
getI32Imm(63 - Shift));
}
// Add in the last bits as required.
if ((Hi = (Remainder >> 16) & 0xFFFF)) {
Result = CurDAG->getMachineNode(PPC::ORIS8, dl, MVT::i64,
SDValue(Result, 0), getI32Imm(Hi));
}
if ((Lo = Remainder & 0xFFFF)) {
Result = CurDAG->getMachineNode(PPC::ORI8, dl, MVT::i64,
SDValue(Result, 0), getI32Imm(Lo));
}
return Result;
}
static SDNode *selectI64Imm(SelectionDAG *CurDAG, const SDLoc &dl,
int64_t Imm) {
unsigned Count = selectI64ImmInstrCountDirect(Imm);
// If the instruction count is 1 or 2, we do not need further analysis
// since rotate + load constant requires at least 2 instructions.
if (Count <= 2)
return selectI64ImmDirect(CurDAG, dl, Imm);
unsigned RMin = 0;
int64_t MatImm;
unsigned MaskEnd;
for (unsigned r = 1; r < 63; ++r) {
uint64_t RImm = Rot64(Imm, r);
unsigned RCount = selectI64ImmInstrCountDirect(RImm) + 1;
if (RCount < Count) {
Count = RCount;
RMin = r;
MatImm = RImm;
MaskEnd = 63;
}
// If the immediate to generate has many trailing zeros, it might be
// worthwhile to generate a rotated value with too many leading ones
// (because that's free with li/lis's sign-extension semantics), and then
// mask them off after rotation.
unsigned LS = findLastSet(RImm);
// We're adding (63-LS) higher-order ones, and we expect to mask them off
// after performing the inverse rotation by (64-r). So we need that:
// 63-LS == 64-r => LS == r-1
if (LS != r-1)
continue;
uint64_t OnesMask = -(int64_t) (UINT64_C(1) << (LS+1));
uint64_t RImmWithOnes = RImm | OnesMask;
RCount = selectI64ImmInstrCountDirect(RImmWithOnes) + 1;
if (RCount < Count) {
Count = RCount;
RMin = r;
MatImm = RImmWithOnes;
MaskEnd = LS;
}
}
if (!RMin)
return selectI64ImmDirect(CurDAG, dl, Imm);
auto getI32Imm = [CurDAG, dl](unsigned Imm) {
return CurDAG->getTargetConstant(Imm, dl, MVT::i32);
};
SDValue Val = SDValue(selectI64ImmDirect(CurDAG, dl, MatImm), 0);
return CurDAG->getMachineNode(PPC::RLDICR, dl, MVT::i64, Val,
getI32Imm(64 - RMin), getI32Imm(MaskEnd));
}
static unsigned allUsesTruncate(SelectionDAG *CurDAG, SDNode *N) {
unsigned MaxTruncation = 0;
// Cannot use range-based for loop here as we need the actual use (i.e. we
// need the operand number corresponding to the use). A range-based for
// will unbox the use and provide an SDNode*.
for (SDNode::use_iterator Use = N->use_begin(), UseEnd = N->use_end();
Use != UseEnd; ++Use) {
unsigned Opc =
Use->isMachineOpcode() ? Use->getMachineOpcode() : Use->getOpcode();
switch (Opc) {
default: return 0;
case ISD::TRUNCATE:
if (Use->isMachineOpcode())
return 0;
MaxTruncation =
std::max(MaxTruncation, Use->getValueType(0).getSizeInBits());
continue;
case ISD::STORE: {
if (Use->isMachineOpcode())
return 0;
StoreSDNode *STN = cast<StoreSDNode>(*Use);
unsigned MemVTSize = STN->getMemoryVT().getSizeInBits();
if (MemVTSize == 64 || Use.getOperandNo() != 0)
return 0;
MaxTruncation = std::max(MaxTruncation, MemVTSize);
continue;
}
case PPC::STW8:
case PPC::STWX8:
case PPC::STWU8:
case PPC::STWUX8:
if (Use.getOperandNo() != 0)
return 0;
MaxTruncation = std::max(MaxTruncation, 32u);
continue;
case PPC::STH8:
case PPC::STHX8:
case PPC::STHU8:
case PPC::STHUX8:
if (Use.getOperandNo() != 0)
return 0;
MaxTruncation = std::max(MaxTruncation, 16u);
continue;
case PPC::STB8:
case PPC::STBX8:
case PPC::STBU8:
case PPC::STBUX8:
if (Use.getOperandNo() != 0)
return 0;
MaxTruncation = std::max(MaxTruncation, 8u);
continue;
}
}
return MaxTruncation;
}
// Select a 64-bit constant.
static SDNode *selectI64Imm(SelectionDAG *CurDAG, SDNode *N) {
SDLoc dl(N);
// Get 64 bit value.
int64_t Imm = cast<ConstantSDNode>(N)->getZExtValue();
if (unsigned MinSize = allUsesTruncate(CurDAG, N)) {
uint64_t SextImm = SignExtend64(Imm, MinSize);
SDValue SDImm = CurDAG->getTargetConstant(SextImm, dl, MVT::i64);
if (isInt<16>(SextImm))
return CurDAG->getMachineNode(PPC::LI8, dl, MVT::i64, SDImm);
}
return selectI64Imm(CurDAG, dl, Imm);
}
namespace {
class BitPermutationSelector {
struct ValueBit {
SDValue V;
// The bit number in the value, using a convention where bit 0 is the
// lowest-order bit.
unsigned Idx;
// ConstZero means a bit we need to mask off.
// Variable is a bit comes from an input variable.
// VariableKnownToBeZero is also a bit comes from an input variable,
// but it is known to be already zero. So we do not need to mask them.
enum Kind {
ConstZero,
Variable,
VariableKnownToBeZero
} K;
ValueBit(SDValue V, unsigned I, Kind K = Variable)
: V(V), Idx(I), K(K) {}
ValueBit(Kind K = Variable)
: V(SDValue(nullptr, 0)), Idx(UINT32_MAX), K(K) {}
bool isZero() const {
return K == ConstZero || K == VariableKnownToBeZero;
}
bool hasValue() const {
return K == Variable || K == VariableKnownToBeZero;
}
SDValue getValue() const {
assert(hasValue() && "Cannot get the value of a constant bit");
return V;
}
unsigned getValueBitIndex() const {
assert(hasValue() && "Cannot get the value bit index of a constant bit");
return Idx;
}
};
// A bit group has the same underlying value and the same rotate factor.
struct BitGroup {
SDValue V;
unsigned RLAmt;
unsigned StartIdx, EndIdx;
// This rotation amount assumes that the lower 32 bits of the quantity are
// replicated in the high 32 bits by the rotation operator (which is done
// by rlwinm and friends in 64-bit mode).
bool Repl32;
// Did converting to Repl32 == true change the rotation factor? If it did,
// it decreased it by 32.
bool Repl32CR;
// Was this group coalesced after setting Repl32 to true?
bool Repl32Coalesced;
BitGroup(SDValue V, unsigned R, unsigned S, unsigned E)
: V(V), RLAmt(R), StartIdx(S), EndIdx(E), Repl32(false), Repl32CR(false),
Repl32Coalesced(false) {
LLVM_DEBUG(dbgs() << "\tbit group for " << V.getNode() << " RLAmt = " << R
<< " [" << S << ", " << E << "]\n");
}
};
// Information on each (Value, RLAmt) pair (like the number of groups
// associated with each) used to choose the lowering method.
struct ValueRotInfo {
SDValue V;
unsigned RLAmt = std::numeric_limits<unsigned>::max();
unsigned NumGroups = 0;
unsigned FirstGroupStartIdx = std::numeric_limits<unsigned>::max();
bool Repl32 = false;
ValueRotInfo() = default;
// For sorting (in reverse order) by NumGroups, and then by
// FirstGroupStartIdx.
bool operator < (const ValueRotInfo &Other) const {
// We need to sort so that the non-Repl32 come first because, when we're
// doing masking, the Repl32 bit groups might be subsumed into the 64-bit
// masking operation.
if (Repl32 < Other.Repl32)
return true;
else if (Repl32 > Other.Repl32)
return false;
else if (NumGroups > Other.NumGroups)
return true;
else if (NumGroups < Other.NumGroups)
return false;
else if (RLAmt == 0 && Other.RLAmt != 0)
return true;
else if (RLAmt != 0 && Other.RLAmt == 0)
return false;
else if (FirstGroupStartIdx < Other.FirstGroupStartIdx)
return true;
return false;
}
};
using ValueBitsMemoizedValue = std::pair<bool, SmallVector<ValueBit, 64>>;
using ValueBitsMemoizer =
DenseMap<SDValue, std::unique_ptr<ValueBitsMemoizedValue>>;
ValueBitsMemoizer Memoizer;
// Return a pair of bool and a SmallVector pointer to a memoization entry.
// The bool is true if something interesting was deduced, otherwise if we're
// providing only a generic representation of V (or something else likewise
// uninteresting for instruction selection) through the SmallVector.
std::pair<bool, SmallVector<ValueBit, 64> *> getValueBits(SDValue V,
unsigned NumBits) {
auto &ValueEntry = Memoizer[V];
if (ValueEntry)
return std::make_pair(ValueEntry->first, &ValueEntry->second);
ValueEntry.reset(new ValueBitsMemoizedValue());
bool &Interesting = ValueEntry->first;
SmallVector<ValueBit, 64> &Bits = ValueEntry->second;
Bits.resize(NumBits);
switch (V.getOpcode()) {
default: break;
case ISD::ROTL:
if (isa<ConstantSDNode>(V.getOperand(1))) {
unsigned RotAmt = V.getConstantOperandVal(1);
const auto &LHSBits = *getValueBits(V.getOperand(0), NumBits).second;
for (unsigned i = 0; i < NumBits; ++i)
Bits[i] = LHSBits[i < RotAmt ? i + (NumBits - RotAmt) : i - RotAmt];
return std::make_pair(Interesting = true, &Bits);
}
break;
case ISD::SHL:
if (isa<ConstantSDNode>(V.getOperand(1))) {
unsigned ShiftAmt = V.getConstantOperandVal(1);
const auto &LHSBits = *getValueBits(V.getOperand(0), NumBits).second;
for (unsigned i = ShiftAmt; i < NumBits; ++i)
Bits[i] = LHSBits[i - ShiftAmt];
for (unsigned i = 0; i < ShiftAmt; ++i)
Bits[i] = ValueBit(ValueBit::ConstZero);
return std::make_pair(Interesting = true, &Bits);
}
break;
case ISD::SRL:
if (isa<ConstantSDNode>(V.getOperand(1))) {
unsigned ShiftAmt = V.getConstantOperandVal(1);
const auto &LHSBits = *getValueBits(V.getOperand(0), NumBits).second;
for (unsigned i = 0; i < NumBits - ShiftAmt; ++i)
Bits[i] = LHSBits[i + ShiftAmt];
for (unsigned i = NumBits - ShiftAmt; i < NumBits; ++i)
Bits[i] = ValueBit(ValueBit::ConstZero);
return std::make_pair(Interesting = true, &Bits);
}
break;
case ISD::AND:
if (isa<ConstantSDNode>(V.getOperand(1))) {
uint64_t Mask = V.getConstantOperandVal(1);
const SmallVector<ValueBit, 64> *LHSBits;
// Mark this as interesting, only if the LHS was also interesting. This
// prevents the overall procedure from matching a single immediate 'and'
// (which is non-optimal because such an and might be folded with other
// things if we don't select it here).
std::tie(Interesting, LHSBits) = getValueBits(V.getOperand(0), NumBits);
for (unsigned i = 0; i < NumBits; ++i)
if (((Mask >> i) & 1) == 1)
Bits[i] = (*LHSBits)[i];
else {
// AND instruction masks this bit. If the input is already zero,
// we have nothing to do here. Otherwise, make the bit ConstZero.
if ((*LHSBits)[i].isZero())
Bits[i] = (*LHSBits)[i];
else
Bits[i] = ValueBit(ValueBit::ConstZero);
}
return std::make_pair(Interesting, &Bits);
}
break;
case ISD::OR: {
const auto &LHSBits = *getValueBits(V.getOperand(0), NumBits).second;
const auto &RHSBits = *getValueBits(V.getOperand(1), NumBits).second;
bool AllDisjoint = true;
SDValue LastVal = SDValue();
unsigned LastIdx = 0;
for (unsigned i = 0; i < NumBits; ++i) {
if (LHSBits[i].isZero() && RHSBits[i].isZero()) {
// If both inputs are known to be zero and one is ConstZero and
// another is VariableKnownToBeZero, we can select whichever
// we like. To minimize the number of bit groups, we select
// VariableKnownToBeZero if this bit is the next bit of the same
// input variable from the previous bit. Otherwise, we select
// ConstZero.
if (LHSBits[i].hasValue() && LHSBits[i].getValue() == LastVal &&
LHSBits[i].getValueBitIndex() == LastIdx + 1)
Bits[i] = LHSBits[i];
else if (RHSBits[i].hasValue() && RHSBits[i].getValue() == LastVal &&
RHSBits[i].getValueBitIndex() == LastIdx + 1)
Bits[i] = RHSBits[i];
else
Bits[i] = ValueBit(ValueBit::ConstZero);
}
else if (LHSBits[i].isZero())
Bits[i] = RHSBits[i];
else if (RHSBits[i].isZero())
Bits[i] = LHSBits[i];
else {
AllDisjoint = false;
break;
}
// We remember the value and bit index of this bit.
if (Bits[i].hasValue()) {
LastVal = Bits[i].getValue();
LastIdx = Bits[i].getValueBitIndex();
}
else {
if (LastVal) LastVal = SDValue();
LastIdx = 0;
}
}
if (!AllDisjoint)
break;
return std::make_pair(Interesting = true, &Bits);
}
case ISD::ZERO_EXTEND: {
// We support only the case with zero extension from i32 to i64 so far.
if (V.getValueType() != MVT::i64 ||
V.getOperand(0).getValueType() != MVT::i32)
break;
const SmallVector<ValueBit, 64> *LHSBits;
const unsigned NumOperandBits = 32;
std::tie(Interesting, LHSBits) = getValueBits(V.getOperand(0),
NumOperandBits);
for (unsigned i = 0; i < NumOperandBits; ++i)
Bits[i] = (*LHSBits)[i];
for (unsigned i = NumOperandBits; i < NumBits; ++i)
Bits[i] = ValueBit(ValueBit::ConstZero);
return std::make_pair(Interesting, &Bits);
}
case ISD::TRUNCATE: {
EVT FromType = V.getOperand(0).getValueType();
EVT ToType = V.getValueType();
// We support only the case with truncate from i64 to i32.
if (FromType != MVT::i64 || ToType != MVT::i32)
break;
const unsigned NumAllBits = FromType.getSizeInBits();
SmallVector<ValueBit, 64> *InBits;
std::tie(Interesting, InBits) = getValueBits(V.getOperand(0),
NumAllBits);
const unsigned NumValidBits = ToType.getSizeInBits();
// A 32-bit instruction cannot touch upper 32-bit part of 64-bit value.
// So, we cannot include this truncate.
bool UseUpper32bit = false;
for (unsigned i = 0; i < NumValidBits; ++i)
if ((*InBits)[i].hasValue() && (*InBits)[i].getValueBitIndex() >= 32) {
UseUpper32bit = true;
break;
}
if (UseUpper32bit)
break;
for (unsigned i = 0; i < NumValidBits; ++i)
Bits[i] = (*InBits)[i];
return std::make_pair(Interesting, &Bits);
}
case ISD::AssertZext: {
// For AssertZext, we look through the operand and
// mark the bits known to be zero.
const SmallVector<ValueBit, 64> *LHSBits;
std::tie(Interesting, LHSBits) = getValueBits(V.getOperand(0),
NumBits);
EVT FromType = cast<VTSDNode>(V.getOperand(1))->getVT();
const unsigned NumValidBits = FromType.getSizeInBits();
for (unsigned i = 0; i < NumValidBits; ++i)
Bits[i] = (*LHSBits)[i];
// These bits are known to be zero.
for (unsigned i = NumValidBits; i < NumBits; ++i)
Bits[i] = ValueBit((*LHSBits)[i].getValue(),
(*LHSBits)[i].getValueBitIndex(),
ValueBit::VariableKnownToBeZero);
return std::make_pair(Interesting, &Bits);
}
case ISD::LOAD:
LoadSDNode *LD = cast<LoadSDNode>(V);
if (ISD::isZEXTLoad(V.getNode()) && V.getResNo() == 0) {
EVT VT = LD->getMemoryVT();
const unsigned NumValidBits = VT.getSizeInBits();
for (unsigned i = 0; i < NumValidBits; ++i)
Bits[i] = ValueBit(V, i);
// These bits are known to be zero.
for (unsigned i = NumValidBits; i < NumBits; ++i)
Bits[i] = ValueBit(V, i, ValueBit::VariableKnownToBeZero);
// Zero-extending load itself cannot be optimized. So, it is not
// interesting by itself though it gives useful information.
return std::make_pair(Interesting = false, &Bits);
}
break;
}
for (unsigned i = 0; i < NumBits; ++i)
Bits[i] = ValueBit(V, i);
return std::make_pair(Interesting = false, &Bits);
}
// For each value (except the constant ones), compute the left-rotate amount
// to get it from its original to final position.
void computeRotationAmounts() {
NeedMask = false;
RLAmt.resize(Bits.size());
for (unsigned i = 0; i < Bits.size(); ++i)
if (Bits[i].hasValue()) {
unsigned VBI = Bits[i].getValueBitIndex();
if (i >= VBI)
RLAmt[i] = i - VBI;
else
RLAmt[i] = Bits.size() - (VBI - i);
} else if (Bits[i].isZero()) {
NeedMask = true;
RLAmt[i] = UINT32_MAX;
} else {
llvm_unreachable("Unknown value bit type");
}
}
// Collect groups of consecutive bits with the same underlying value and
// rotation factor. If we're doing late masking, we ignore zeros, otherwise
// they break up groups.
void collectBitGroups(bool LateMask) {
BitGroups.clear();
unsigned LastRLAmt = RLAmt[0];
SDValue LastValue = Bits[0].hasValue() ? Bits[0].getValue() : SDValue();
unsigned LastGroupStartIdx = 0;
bool IsGroupOfZeros = !Bits[LastGroupStartIdx].hasValue();
for (unsigned i = 1; i < Bits.size(); ++i) {
unsigned ThisRLAmt = RLAmt[i];
SDValue ThisValue = Bits[i].hasValue() ? Bits[i].getValue() : SDValue();
if (LateMask && !ThisValue) {
ThisValue = LastValue;
ThisRLAmt = LastRLAmt;
// If we're doing late masking, then the first bit group always starts
// at zero (even if the first bits were zero).
if (BitGroups.empty())
LastGroupStartIdx = 0;
}
// If this bit is known to be zero and the current group is a bit group
// of zeros, we do not need to terminate the current bit group even the
// Value or RLAmt does not match here. Instead, we terminate this group
// when the first non-zero bit appears later.
if (IsGroupOfZeros && Bits[i].isZero())
continue;
// If this bit has the same underlying value and the same rotate factor as
// the last one, then they're part of the same group.
if (ThisRLAmt == LastRLAmt && ThisValue == LastValue)
// We cannot continue the current group if this bits is not known to
// be zero in a bit group of zeros.
if (!(IsGroupOfZeros && ThisValue && !Bits[i].isZero()))
continue;
if (LastValue.getNode())
BitGroups.push_back(BitGroup(LastValue, LastRLAmt, LastGroupStartIdx,
i-1));
LastRLAmt = ThisRLAmt;
LastValue = ThisValue;
LastGroupStartIdx = i;
IsGroupOfZeros = !Bits[LastGroupStartIdx].hasValue();
}
if (LastValue.getNode())
BitGroups.push_back(BitGroup(LastValue, LastRLAmt, LastGroupStartIdx,
Bits.size()-1));
if (BitGroups.empty())
return;
// We might be able to combine the first and last groups.
if (BitGroups.size() > 1) {
// If the first and last groups are the same, then remove the first group
// in favor of the last group, making the ending index of the last group
// equal to the ending index of the to-be-removed first group.
if (BitGroups[0].StartIdx == 0 &&
BitGroups[BitGroups.size()-1].EndIdx == Bits.size()-1 &&
BitGroups[0].V == BitGroups[BitGroups.size()-1].V &&
BitGroups[0].RLAmt == BitGroups[BitGroups.size()-1].RLAmt) {
LLVM_DEBUG(dbgs() << "\tcombining final bit group with initial one\n");
BitGroups[BitGroups.size()-1].EndIdx = BitGroups[0].EndIdx;
BitGroups.erase(BitGroups.begin());
}
}
}
// Take all (SDValue, RLAmt) pairs and sort them by the number of groups
// associated with each. If the number of groups are same, we prefer a group
// which does not require rotate, i.e. RLAmt is 0, to avoid the first rotate
// instruction. If there is a degeneracy, pick the one that occurs
// first (in the final value).
void collectValueRotInfo() {
ValueRots.clear();
for (auto &BG : BitGroups) {
unsigned RLAmtKey = BG.RLAmt + (BG.Repl32 ? 64 : 0);
ValueRotInfo &VRI = ValueRots[std::make_pair(BG.V, RLAmtKey)];
VRI.V = BG.V;
VRI.RLAmt = BG.RLAmt;
VRI.Repl32 = BG.Repl32;
VRI.NumGroups += 1;
VRI.FirstGroupStartIdx = std::min(VRI.FirstGroupStartIdx, BG.StartIdx);
}
// Now that we've collected the various ValueRotInfo instances, we need to
// sort them.
ValueRotsVec.clear();
for (auto &I : ValueRots) {
ValueRotsVec.push_back(I.second);
}
llvm::sort(ValueRotsVec);
}
// In 64-bit mode, rlwinm and friends have a rotation operator that
// replicates the low-order 32 bits into the high-order 32-bits. The mask
// indices of these instructions can only be in the lower 32 bits, so they
// can only represent some 64-bit bit groups. However, when they can be used,
// the 32-bit replication can be used to represent, as a single bit group,
// otherwise separate bit groups. We'll convert to replicated-32-bit bit
// groups when possible. Returns true if any of the bit groups were
// converted.
void assignRepl32BitGroups() {
// If we have bits like this:
//
// Indices: 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
// V bits: ... 7 6 5 4 3 2 1 0 31 30 29 28 27 26 25 24
// Groups: | RLAmt = 8 | RLAmt = 40 |
//
// But, making use of a 32-bit operation that replicates the low-order 32
// bits into the high-order 32 bits, this can be one bit group with a RLAmt
// of 8.
auto IsAllLow32 = [this](BitGroup & BG) {
if (BG.StartIdx <= BG.EndIdx) {
for (unsigned i = BG.StartIdx; i <= BG.EndIdx; ++i) {
if (!Bits[i].hasValue())
continue;
if (Bits[i].getValueBitIndex() >= 32)
return false;
}
} else {
for (unsigned i = BG.StartIdx; i < Bits.size(); ++i) {
if (!Bits[i].hasValue())
continue;
if (Bits[i].getValueBitIndex() >= 32)
return false;
}
for (unsigned i = 0; i <= BG.EndIdx; ++i) {
if (!Bits[i].hasValue())
continue;
if (Bits[i].getValueBitIndex() >= 32)
return false;
}
}
return true;
};
for (auto &BG : BitGroups) {
// If this bit group has RLAmt of 0 and will not be merged with
// another bit group, we don't benefit from Repl32. We don't mark
// such group to give more freedom for later instruction selection.
if (BG.RLAmt == 0) {
auto PotentiallyMerged = [this](BitGroup & BG) {
for (auto &BG2 : BitGroups)
if (&BG != &BG2 && BG.V == BG2.V &&
(BG2.RLAmt == 0 || BG2.RLAmt == 32))
return true;
return false;
};
if (!PotentiallyMerged(BG))
continue;
}
if (BG.StartIdx < 32 && BG.EndIdx < 32) {
if (IsAllLow32(BG)) {
if (BG.RLAmt >= 32) {
BG.RLAmt -= 32;
BG.Repl32CR = true;
}
BG.Repl32 = true;
LLVM_DEBUG(dbgs() << "\t32-bit replicated bit group for "
<< BG.V.getNode() << " RLAmt = " << BG.RLAmt << " ["
<< BG.StartIdx << ", " << BG.EndIdx << "]\n");
}
}
}
// Now walk through the bit groups, consolidating where possible.
for (auto I = BitGroups.begin(); I != BitGroups.end();) {
// We might want to remove this bit group by merging it with the previous
// group (which might be the ending group).
auto IP = (I == BitGroups.begin()) ?
std::prev(BitGroups.end()) : std::prev(I);
if (I->Repl32 && IP->Repl32 && I->V == IP->V && I->RLAmt == IP->RLAmt &&
I->StartIdx == (IP->EndIdx + 1) % 64 && I != IP) {
LLVM_DEBUG(dbgs() << "\tcombining 32-bit replicated bit group for "
<< I->V.getNode() << " RLAmt = " << I->RLAmt << " ["
<< I->StartIdx << ", " << I->EndIdx
<< "] with group with range [" << IP->StartIdx << ", "
<< IP->EndIdx << "]\n");
IP->EndIdx = I->EndIdx;
IP->Repl32CR = IP->Repl32CR || I->Repl32CR;
IP->Repl32Coalesced = true;
I = BitGroups.erase(I);
continue;
} else {
// There is a special case worth handling: If there is a single group
// covering the entire upper 32 bits, and it can be merged with both
// the next and previous groups (which might be the same group), then
// do so. If it is the same group (so there will be only one group in
// total), then we need to reverse the order of the range so that it
// covers the entire 64 bits.
if (I->StartIdx == 32 && I->EndIdx == 63) {
assert(std::next(I) == BitGroups.end() &&
"bit group ends at index 63 but there is another?");
auto IN = BitGroups.begin();
if (IP->Repl32 && IN->Repl32 && I->V == IP->V && I->V == IN->V &&
(I->RLAmt % 32) == IP->RLAmt && (I->RLAmt % 32) == IN->RLAmt &&
IP->EndIdx == 31 && IN->StartIdx == 0 && I != IP &&
IsAllLow32(*I)) {
LLVM_DEBUG(dbgs() << "\tcombining bit group for " << I->V.getNode()
<< " RLAmt = " << I->RLAmt << " [" << I->StartIdx
<< ", " << I->EndIdx
<< "] with 32-bit replicated groups with ranges ["
<< IP->StartIdx << ", " << IP->EndIdx << "] and ["
<< IN->StartIdx << ", " << IN->EndIdx << "]\n");
if (IP == IN) {
// There is only one other group; change it to cover the whole
// range (backward, so that it can still be Repl32 but cover the
// whole 64-bit range).
IP->StartIdx = 31;
IP->EndIdx = 30;
IP->Repl32CR = IP->Repl32CR || I->RLAmt >= 32;
IP->Repl32Coalesced = true;
I = BitGroups.erase(I);
} else {
// There are two separate groups, one before this group and one
// after us (at the beginning). We're going to remove this group,
// but also the group at the very beginning.
IP->EndIdx = IN->EndIdx;
IP->Repl32CR = IP->Repl32CR || IN->Repl32CR || I->RLAmt >= 32;
IP->Repl32Coalesced = true;
I = BitGroups.erase(I);
BitGroups.erase(BitGroups.begin());
}
// This must be the last group in the vector (and we might have
// just invalidated the iterator above), so break here.
break;
}
}
}
++I;
}
}
SDValue getI32Imm(unsigned Imm, const SDLoc &dl) {
return CurDAG->getTargetConstant(Imm, dl, MVT::i32);
}
uint64_t getZerosMask() {
uint64_t Mask = 0;
for (unsigned i = 0; i < Bits.size(); ++i) {
if (Bits[i].hasValue())
continue;
Mask |= (UINT64_C(1) << i);
}
return ~Mask;
}
// This method extends an input value to 64 bit if input is 32-bit integer.
// While selecting instructions in BitPermutationSelector in 64-bit mode,
// an input value can be a 32-bit integer if a ZERO_EXTEND node is included.
// In such case, we extend it to 64 bit to be consistent with other values.
SDValue ExtendToInt64(SDValue V, const SDLoc &dl) {
if (V.getValueSizeInBits() == 64)
return V;
assert(V.getValueSizeInBits() == 32);
SDValue SubRegIdx = CurDAG->getTargetConstant(PPC::sub_32, dl, MVT::i32);
SDValue ImDef = SDValue(CurDAG->getMachineNode(PPC::IMPLICIT_DEF, dl,
MVT::i64), 0);
SDValue ExtVal = SDValue(CurDAG->getMachineNode(PPC::INSERT_SUBREG, dl,
MVT::i64, ImDef, V,
SubRegIdx), 0);
return ExtVal;
}
SDValue TruncateToInt32(SDValue V, const SDLoc &dl) {
if (V.getValueSizeInBits() == 32)
return V;
assert(V.getValueSizeInBits() == 64);
SDValue SubRegIdx = CurDAG->getTargetConstant(PPC::sub_32, dl, MVT::i32);
SDValue SubVal = SDValue(CurDAG->getMachineNode(PPC::EXTRACT_SUBREG, dl,
MVT::i32, V, SubRegIdx), 0);
return SubVal;
}
// Depending on the number of groups for a particular value, it might be
// better to rotate, mask explicitly (using andi/andis), and then or the
// result. Select this part of the result first.
void SelectAndParts32(const SDLoc &dl, SDValue &Res, unsigned *InstCnt) {
if (BPermRewriterNoMasking)
return;
for (ValueRotInfo &VRI : ValueRotsVec) {
unsigned Mask = 0;
for (unsigned i = 0; i < Bits.size(); ++i) {
if (!Bits[i].hasValue() || Bits[i].getValue() != VRI.V)
continue;
if (RLAmt[i] != VRI.RLAmt)
continue;
Mask |= (1u << i);
}
// Compute the masks for andi/andis that would be necessary.
unsigned ANDIMask = (Mask & UINT16_MAX), ANDISMask = Mask >> 16;
assert((ANDIMask != 0 || ANDISMask != 0) &&
"No set bits in mask for value bit groups");
bool NeedsRotate = VRI.RLAmt != 0;
// We're trying to minimize the number of instructions. If we have one
// group, using one of andi/andis can break even. If we have three
// groups, we can use both andi and andis and break even (to use both
// andi and andis we also need to or the results together). We need four
// groups if we also need to rotate. To use andi/andis we need to do more
// than break even because rotate-and-mask instructions tend to be easier
// to schedule.
// FIXME: We've biased here against using andi/andis, which is right for
// POWER cores, but not optimal everywhere. For example, on the A2,
// andi/andis have single-cycle latency whereas the rotate-and-mask
// instructions take two cycles, and it would be better to bias toward
// andi/andis in break-even cases.
unsigned NumAndInsts = (unsigned) NeedsRotate +
(unsigned) (ANDIMask != 0) +
(unsigned) (ANDISMask != 0) +
(unsigned) (ANDIMask != 0 && ANDISMask != 0) +
(unsigned) (bool) Res;
LLVM_DEBUG(dbgs() << "\t\trotation groups for " << VRI.V.getNode()
<< " RL: " << VRI.RLAmt << ":"
<< "\n\t\t\tisel using masking: " << NumAndInsts
<< " using rotates: " << VRI.NumGroups << "\n");
if (NumAndInsts >= VRI.NumGroups)
continue;
LLVM_DEBUG(dbgs() << "\t\t\t\tusing masking\n");
if (InstCnt) *InstCnt += NumAndInsts;
SDValue VRot;
if (VRI.RLAmt) {
SDValue Ops[] =
{ TruncateToInt32(VRI.V, dl), getI32Imm(VRI.RLAmt, dl),
getI32Imm(0, dl), getI32Imm(31, dl) };
VRot = SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32,
Ops), 0);
} else {
VRot = TruncateToInt32(VRI.V, dl);
}
SDValue ANDIVal, ANDISVal;
if (ANDIMask != 0)
ANDIVal = SDValue(CurDAG->getMachineNode(PPC::ANDIo, dl, MVT::i32,
VRot, getI32Imm(ANDIMask, dl)), 0);
if (ANDISMask != 0)
ANDISVal = SDValue(CurDAG->getMachineNode(PPC::ANDISo, dl, MVT::i32,
VRot, getI32Imm(ANDISMask, dl)), 0);
SDValue TotalVal;
if (!ANDIVal)
TotalVal = ANDISVal;
else if (!ANDISVal)
TotalVal = ANDIVal;
else
TotalVal = SDValue(CurDAG->getMachineNode(PPC::OR, dl, MVT::i32,
ANDIVal, ANDISVal), 0);
if (!Res)
Res = TotalVal;
else
Res = SDValue(CurDAG->getMachineNode(PPC::OR, dl, MVT::i32,
Res, TotalVal), 0);
// Now, remove all groups with this underlying value and rotation
// factor.
eraseMatchingBitGroups([VRI](const BitGroup &BG) {
return BG.V == VRI.V && BG.RLAmt == VRI.RLAmt;
});
}
}
// Instruction selection for the 32-bit case.
SDNode *Select32(SDNode *N, bool LateMask, unsigned *InstCnt) {
SDLoc dl(N);
SDValue Res;
if (InstCnt) *InstCnt = 0;
// Take care of cases that should use andi/andis first.
SelectAndParts32(dl, Res, InstCnt);
// If we've not yet selected a 'starting' instruction, and we have no zeros
// to fill in, select the (Value, RLAmt) with the highest priority (largest
// number of groups), and start with this rotated value.
if ((!NeedMask || LateMask) && !Res) {
ValueRotInfo &VRI = ValueRotsVec[0];
if (VRI.RLAmt) {
if (InstCnt) *InstCnt += 1;
SDValue Ops[] =
{ TruncateToInt32(VRI.V, dl), getI32Imm(VRI.RLAmt, dl),
getI32Imm(0, dl), getI32Imm(31, dl) };
Res = SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops),
0);
} else {
Res = TruncateToInt32(VRI.V, dl);
}
// Now, remove all groups with this underlying value and rotation factor.
eraseMatchingBitGroups([VRI](const BitGroup &BG) {
return BG.V == VRI.V && BG.RLAmt == VRI.RLAmt;
});
}
if (InstCnt) *InstCnt += BitGroups.size();
// Insert the other groups (one at a time).
for (auto &BG : BitGroups) {
if (!Res) {
SDValue Ops[] =
{ TruncateToInt32(BG.V, dl), getI32Imm(BG.RLAmt, dl),
getI32Imm(Bits.size() - BG.EndIdx - 1, dl),
getI32Imm(Bits.size() - BG.StartIdx - 1, dl) };
Res = SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops), 0);
} else {
SDValue Ops[] =
{ Res, TruncateToInt32(BG.V, dl), getI32Imm(BG.RLAmt, dl),
getI32Imm(Bits.size() - BG.EndIdx - 1, dl),
getI32Imm(Bits.size() - BG.StartIdx - 1, dl) };
Res = SDValue(CurDAG->getMachineNode(PPC::RLWIMI, dl, MVT::i32, Ops), 0);
}
}
if (LateMask) {
unsigned Mask = (unsigned) getZerosMask();
unsigned ANDIMask = (Mask & UINT16_MAX), ANDISMask = Mask >> 16;
assert((ANDIMask != 0 || ANDISMask != 0) &&
"No set bits in zeros mask?");
if (InstCnt) *InstCnt += (unsigned) (ANDIMask != 0) +
(unsigned) (ANDISMask != 0) +
(unsigned) (ANDIMask != 0 && ANDISMask != 0);
SDValue ANDIVal, ANDISVal;
if (ANDIMask != 0)
ANDIVal = SDValue(CurDAG->getMachineNode(PPC::ANDIo, dl, MVT::i32,
Res, getI32Imm(ANDIMask, dl)), 0);
if (ANDISMask != 0)
ANDISVal = SDValue(CurDAG->getMachineNode(PPC::ANDISo, dl, MVT::i32,
Res, getI32Imm(ANDISMask, dl)), 0);
if (!ANDIVal)
Res = ANDISVal;
else if (!ANDISVal)
Res = ANDIVal;
else
Res = SDValue(CurDAG->getMachineNode(PPC::OR, dl, MVT::i32,
ANDIVal, ANDISVal), 0);
}
return Res.getNode();
}
unsigned SelectRotMask64Count(unsigned RLAmt, bool Repl32,
unsigned MaskStart, unsigned MaskEnd,
bool IsIns) {
// In the notation used by the instructions, 'start' and 'end' are reversed
// because bits are counted from high to low order.
unsigned InstMaskStart = 64 - MaskEnd - 1,
InstMaskEnd = 64 - MaskStart - 1;
if (Repl32)
return 1;
if ((!IsIns && (InstMaskEnd == 63 || InstMaskStart == 0)) ||
InstMaskEnd == 63 - RLAmt)
return 1;
return 2;
}
// For 64-bit values, not all combinations of rotates and masks are
// available. Produce one if it is available.
SDValue SelectRotMask64(SDValue V, const SDLoc &dl, unsigned RLAmt,
bool Repl32, unsigned MaskStart, unsigned MaskEnd,
unsigned *InstCnt = nullptr) {
// In the notation used by the instructions, 'start' and 'end' are reversed
// because bits are counted from high to low order.
unsigned InstMaskStart = 64 - MaskEnd - 1,
InstMaskEnd = 64 - MaskStart - 1;
if (InstCnt) *InstCnt += 1;
if (Repl32) {
// This rotation amount assumes that the lower 32 bits of the quantity
// are replicated in the high 32 bits by the rotation operator (which is
// done by rlwinm and friends).
assert(InstMaskStart >= 32 && "Mask cannot start out of range");
assert(InstMaskEnd >= 32 && "Mask cannot end out of range");
SDValue Ops[] =
{ ExtendToInt64(V, dl), getI32Imm(RLAmt, dl),
getI32Imm(InstMaskStart - 32, dl), getI32Imm(InstMaskEnd - 32, dl) };
return SDValue(CurDAG->getMachineNode(PPC::RLWINM8, dl, MVT::i64,
Ops), 0);
}
if (InstMaskEnd == 63) {
SDValue Ops[] =
{ ExtendToInt64(V, dl), getI32Imm(RLAmt, dl),
getI32Imm(InstMaskStart, dl) };
return SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64, Ops), 0);
}
if (InstMaskStart == 0) {
SDValue Ops[] =
{ ExtendToInt64(V, dl), getI32Imm(RLAmt, dl),
getI32Imm(InstMaskEnd, dl) };
return SDValue(CurDAG->getMachineNode(PPC::RLDICR, dl, MVT::i64, Ops), 0);
}
if (InstMaskEnd == 63 - RLAmt) {
SDValue Ops[] =
{ ExtendToInt64(V, dl), getI32Imm(RLAmt, dl),
getI32Imm(InstMaskStart, dl) };
return SDValue(CurDAG->getMachineNode(PPC::RLDIC, dl, MVT::i64, Ops), 0);
}
// We cannot do this with a single instruction, so we'll use two. The
// problem is that we're not free to choose both a rotation amount and mask
// start and end independently. We can choose an arbitrary mask start and
// end, but then the rotation amount is fixed. Rotation, however, can be
// inverted, and so by applying an "inverse" rotation first, we can get the
// desired result.
if (InstCnt) *InstCnt += 1;
// The rotation mask for the second instruction must be MaskStart.
unsigned RLAmt2 = MaskStart;
// The first instruction must rotate V so that the overall rotation amount
// is RLAmt.
unsigned RLAmt1 = (64 + RLAmt - RLAmt2) % 64;
if (RLAmt1)
V = SelectRotMask64(V, dl, RLAmt1, false, 0, 63);
return SelectRotMask64(V, dl, RLAmt2, false, MaskStart, MaskEnd);
}
// For 64-bit values, not all combinations of rotates and masks are
// available. Produce a rotate-mask-and-insert if one is available.
SDValue SelectRotMaskIns64(SDValue Base, SDValue V, const SDLoc &dl,
unsigned RLAmt, bool Repl32, unsigned MaskStart,
unsigned MaskEnd, unsigned *InstCnt = nullptr) {
// In the notation used by the instructions, 'start' and 'end' are reversed
// because bits are counted from high to low order.
unsigned InstMaskStart = 64 - MaskEnd - 1,
InstMaskEnd = 64 - MaskStart - 1;
if (InstCnt) *InstCnt += 1;
if (Repl32) {
// This rotation amount assumes that the lower 32 bits of the quantity
// are replicated in the high 32 bits by the rotation operator (which is
// done by rlwinm and friends).
assert(InstMaskStart >= 32 && "Mask cannot start out of range");
assert(InstMaskEnd >= 32 && "Mask cannot end out of range");
SDValue Ops[] =
{ ExtendToInt64(Base, dl), ExtendToInt64(V, dl), getI32Imm(RLAmt, dl),
getI32Imm(InstMaskStart - 32, dl), getI32Imm(InstMaskEnd - 32, dl) };
return SDValue(CurDAG->getMachineNode(PPC::RLWIMI8, dl, MVT::i64,
Ops), 0);
}
if (InstMaskEnd == 63 - RLAmt) {
SDValue Ops[] =
{ ExtendToInt64(Base, dl), ExtendToInt64(V, dl), getI32Imm(RLAmt, dl),
getI32Imm(InstMaskStart, dl) };
return SDValue(CurDAG->getMachineNode(PPC::RLDIMI, dl, MVT::i64, Ops), 0);
}
// We cannot do this with a single instruction, so we'll use two. The
// problem is that we're not free to choose both a rotation amount and mask
// start and end independently. We can choose an arbitrary mask start and
// end, but then the rotation amount is fixed. Rotation, however, can be
// inverted, and so by applying an "inverse" rotation first, we can get the
// desired result.
if (InstCnt) *InstCnt += 1;
// The rotation mask for the second instruction must be MaskStart.
unsigned RLAmt2 = MaskStart;
// The first instruction must rotate V so that the overall rotation amount
// is RLAmt.
unsigned RLAmt1 = (64 + RLAmt - RLAmt2) % 64;
if (RLAmt1)
V = SelectRotMask64(V, dl, RLAmt1, false, 0, 63);
return SelectRotMaskIns64(Base, V, dl, RLAmt2, false, MaskStart, MaskEnd);
}
void SelectAndParts64(const SDLoc &dl, SDValue &Res, unsigned *InstCnt) {
if (BPermRewriterNoMasking)
return;
// The idea here is the same as in the 32-bit version, but with additional
// complications from the fact that Repl32 might be true. Because we
// aggressively convert bit groups to Repl32 form (which, for small
// rotation factors, involves no other change), and then coalesce, it might
// be the case that a single 64-bit masking operation could handle both
// some Repl32 groups and some non-Repl32 groups. If converting to Repl32
// form allowed coalescing, then we must use a 32-bit rotaton in order to
// completely capture the new combined bit group.
for (ValueRotInfo &VRI : ValueRotsVec) {
uint64_t Mask = 0;
// We need to add to the mask all bits from the associated bit groups.
// If Repl32 is false, we need to add bits from bit groups that have
// Repl32 true, but are trivially convertable to Repl32 false. Such a
// group is trivially convertable if it overlaps only with the lower 32
// bits, and the group has not been coalesced.
auto MatchingBG = [VRI](const BitGroup &BG) {
if (VRI.V != BG.V)
return false;
unsigned EffRLAmt = BG.RLAmt;
if (!VRI.Repl32 && BG.Repl32) {
if (BG.StartIdx < 32 && BG.EndIdx < 32 && BG.StartIdx <= BG.EndIdx &&
!BG.Repl32Coalesced) {
if (BG.Repl32CR)
EffRLAmt += 32;
} else {
return false;
}
} else if (VRI.Repl32 != BG.Repl32) {
return false;
}
return VRI.RLAmt == EffRLAmt;
};
for (auto &BG : BitGroups) {
if (!MatchingBG(BG))
continue;
if (BG.StartIdx <= BG.EndIdx) {
for (unsigned i = BG.StartIdx; i <= BG.EndIdx; ++i)
Mask |= (UINT64_C(1) << i);
} else {
for (unsigned i = BG.StartIdx; i < Bits.size(); ++i)
Mask |= (UINT64_C(1) << i);
for (unsigned i = 0; i <= BG.EndIdx; ++i)
Mask |= (UINT64_C(1) << i);
}
}
// We can use the 32-bit andi/andis technique if the mask does not
// require any higher-order bits. This can save an instruction compared
// to always using the general 64-bit technique.
bool Use32BitInsts = isUInt<32>(Mask);
// Compute the masks for andi/andis that would be necessary.
unsigned ANDIMask = (Mask & UINT16_MAX),
ANDISMask = (Mask >> 16) & UINT16_MAX;
bool NeedsRotate = VRI.RLAmt || (VRI.Repl32 && !isUInt<32>(Mask));
unsigned NumAndInsts = (unsigned) NeedsRotate +
(unsigned) (bool) Res;
if (Use32BitInsts)
NumAndInsts += (unsigned) (ANDIMask != 0) + (unsigned) (ANDISMask != 0) +
(unsigned) (ANDIMask != 0 && ANDISMask != 0);
else
NumAndInsts += selectI64ImmInstrCount(Mask) + /* and */ 1;
unsigned NumRLInsts = 0;
bool FirstBG = true;
bool MoreBG = false;
for (auto &BG : BitGroups) {
if (!MatchingBG(BG)) {
MoreBG = true;
continue;
}
NumRLInsts +=
SelectRotMask64Count(BG.RLAmt, BG.Repl32, BG.StartIdx, BG.EndIdx,
!FirstBG);
FirstBG = false;
}
LLVM_DEBUG(dbgs() << "\t\trotation groups for " << VRI.V.getNode()
<< " RL: " << VRI.RLAmt << (VRI.Repl32 ? " (32):" : ":")
<< "\n\t\t\tisel using masking: " << NumAndInsts
<< " using rotates: " << NumRLInsts << "\n");
// When we'd use andi/andis, we bias toward using the rotates (andi only
// has a record form, and is cracked on POWER cores). However, when using
// general 64-bit constant formation, bias toward the constant form,
// because that exposes more opportunities for CSE.
if (NumAndInsts > NumRLInsts)
continue;
// When merging multiple bit groups, instruction or is used.
// But when rotate is used, rldimi can inert the rotated value into any
// register, so instruction or can be avoided.
if ((Use32BitInsts || MoreBG) && NumAndInsts == NumRLInsts)
continue;
LLVM_DEBUG(dbgs() << "\t\t\t\tusing masking\n");
if (InstCnt) *InstCnt += NumAndInsts;
SDValue VRot;
// We actually need to generate a rotation if we have a non-zero rotation
// factor or, in the Repl32 case, if we care about any of the
// higher-order replicated bits. In the latter case, we generate a mask
// backward so that it actually includes the entire 64 bits.
if (VRI.RLAmt || (VRI.Repl32 && !isUInt<32>(Mask)))
VRot = SelectRotMask64(VRI.V, dl, VRI.RLAmt, VRI.Repl32,
VRI.Repl32 ? 31 : 0, VRI.Repl32 ? 30 : 63);
else
VRot = VRI.V;
SDValue TotalVal;
if (Use32BitInsts) {
assert((ANDIMask != 0 || ANDISMask != 0) &&
"No set bits in mask when using 32-bit ands for 64-bit value");
SDValue ANDIVal, ANDISVal;
if (ANDIMask != 0)
ANDIVal = SDValue(CurDAG->getMachineNode(PPC::ANDIo8, dl, MVT::i64,
ExtendToInt64(VRot, dl),
getI32Imm(ANDIMask, dl)),
0);
if (ANDISMask != 0)
ANDISVal = SDValue(CurDAG->getMachineNode(PPC::ANDISo8, dl, MVT::i64,
ExtendToInt64(VRot, dl),
getI32Imm(ANDISMask, dl)),
0);
if (!ANDIVal)
TotalVal = ANDISVal;
else if (!ANDISVal)
TotalVal = ANDIVal;
else
TotalVal = SDValue(CurDAG->getMachineNode(PPC::OR8, dl, MVT::i64,
ExtendToInt64(ANDIVal, dl), ANDISVal), 0);
} else {
TotalVal = SDValue(selectI64Imm(CurDAG, dl, Mask), 0);
TotalVal =
SDValue(CurDAG->getMachineNode(PPC::AND8, dl, MVT::i64,
ExtendToInt64(VRot, dl), TotalVal),
0);
}
if (!Res)
Res = TotalVal;
else
Res = SDValue(CurDAG->getMachineNode(PPC::OR8, dl, MVT::i64,
ExtendToInt64(Res, dl), TotalVal),
0);
// Now, remove all groups with this underlying value and rotation
// factor.
eraseMatchingBitGroups(MatchingBG);
}
}
// Instruction selection for the 64-bit case.
SDNode *Select64(SDNode *N, bool LateMask, unsigned *InstCnt) {
SDLoc dl(N);
SDValue Res;
if (InstCnt) *InstCnt = 0;
// Take care of cases that should use andi/andis first.
SelectAndParts64(dl, Res, InstCnt);
// If we've not yet selected a 'starting' instruction, and we have no zeros
// to fill in, select the (Value, RLAmt) with the highest priority (largest
// number of groups), and start with this rotated value.
if ((!NeedMask || LateMask) && !Res) {
// If we have both Repl32 groups and non-Repl32 groups, the non-Repl32
// groups will come first, and so the VRI representing the largest number
// of groups might not be first (it might be the first Repl32 groups).
unsigned MaxGroupsIdx = 0;
if (!ValueRotsVec[0].Repl32) {
for (unsigned i = 0, ie = ValueRotsVec.size(); i < ie; ++i)
if (ValueRotsVec[i].Repl32) {
if (ValueRotsVec[i].NumGroups > ValueRotsVec[0].NumGroups)
MaxGroupsIdx = i;
break;
}
}
ValueRotInfo &VRI = ValueRotsVec[MaxGroupsIdx];
bool NeedsRotate = false;
if (VRI.RLAmt) {
NeedsRotate = true;
} else if (VRI.Repl32) {
for (auto &BG : BitGroups) {
if (BG.V != VRI.V || BG.RLAmt != VRI.RLAmt ||
BG.Repl32 != VRI.Repl32)
continue;
// We don't need a rotate if the bit group is confined to the lower
// 32 bits.
if (BG.StartIdx < 32 && BG.EndIdx < 32 && BG.StartIdx < BG.EndIdx)
continue;
NeedsRotate = true;
break;
}
}
if (NeedsRotate)
Res = SelectRotMask64(VRI.V, dl, VRI.RLAmt, VRI.Repl32,
VRI.Repl32 ? 31 : 0, VRI.Repl32 ? 30 : 63,
InstCnt);
else
Res = VRI.V;
// Now, remove all groups with this underlying value and rotation factor.
if (Res)
eraseMatchingBitGroups([VRI](const BitGroup &BG) {
return BG.V == VRI.V && BG.RLAmt == VRI.RLAmt &&
BG.Repl32 == VRI.Repl32;
});
}
// Because 64-bit rotates are more flexible than inserts, we might have a
// preference regarding which one we do first (to save one instruction).
if (!Res)
for (auto I = BitGroups.begin(), IE = BitGroups.end(); I != IE; ++I) {
if (SelectRotMask64Count(I->RLAmt, I->Repl32, I->StartIdx, I->EndIdx,
false) <
SelectRotMask64Count(I->RLAmt, I->Repl32, I->StartIdx, I->EndIdx,
true)) {
if (I != BitGroups.begin()) {
BitGroup BG = *I;
BitGroups.erase(I);
BitGroups.insert(BitGroups.begin(), BG);
}
break;
}
}
// Insert the other groups (one at a time).
for (auto &BG : BitGroups) {
if (!Res)
Res = SelectRotMask64(BG.V, dl, BG.RLAmt, BG.Repl32, BG.StartIdx,
BG.EndIdx, InstCnt);
else
Res = SelectRotMaskIns64(Res, BG.V, dl, BG.RLAmt, BG.Repl32,
BG.StartIdx, BG.EndIdx, InstCnt);
}
if (LateMask) {
uint64_t Mask = getZerosMask();
// We can use the 32-bit andi/andis technique if the mask does not
// require any higher-order bits. This can save an instruction compared
// to always using the general 64-bit technique.
bool Use32BitInsts = isUInt<32>(Mask);
// Compute the masks for andi/andis that would be necessary.
unsigned ANDIMask = (Mask & UINT16_MAX),
ANDISMask = (Mask >> 16) & UINT16_MAX;
if (Use32BitInsts) {
assert((ANDIMask != 0 || ANDISMask != 0) &&
"No set bits in mask when using 32-bit ands for 64-bit value");
if (InstCnt) *InstCnt += (unsigned) (ANDIMask != 0) +
(unsigned) (ANDISMask != 0) +
(unsigned) (ANDIMask != 0 && ANDISMask != 0);
SDValue ANDIVal, ANDISVal;
if (ANDIMask != 0)
ANDIVal = SDValue(CurDAG->getMachineNode(PPC::ANDIo8, dl, MVT::i64,
ExtendToInt64(Res, dl), getI32Imm(ANDIMask, dl)), 0);
if (ANDISMask != 0)
ANDISVal = SDValue(CurDAG->getMachineNode(PPC::ANDISo8, dl, MVT::i64,
ExtendToInt64(Res, dl), getI32Imm(ANDISMask, dl)), 0);
if (!ANDIVal)
Res = ANDISVal;
else if (!ANDISVal)
Res = ANDIVal;
else
Res = SDValue(CurDAG->getMachineNode(PPC::OR8, dl, MVT::i64,
ExtendToInt64(ANDIVal, dl), ANDISVal), 0);
} else {
if (InstCnt) *InstCnt += selectI64ImmInstrCount(Mask) + /* and */ 1;
SDValue MaskVal = SDValue(selectI64Imm(CurDAG, dl, Mask), 0);
Res =
SDValue(CurDAG->getMachineNode(PPC::AND8, dl, MVT::i64,
ExtendToInt64(Res, dl), MaskVal), 0);
}
}
return Res.getNode();
}
SDNode *Select(SDNode *N, bool LateMask, unsigned *InstCnt = nullptr) {
// Fill in BitGroups.
collectBitGroups(LateMask);
if (BitGroups.empty())
return nullptr;
// For 64-bit values, figure out when we can use 32-bit instructions.
if (Bits.size() == 64)
assignRepl32BitGroups();
// Fill in ValueRotsVec.
collectValueRotInfo();
if (Bits.size() == 32) {
return Select32(N, LateMask, InstCnt);
} else {
assert(Bits.size() == 64 && "Not 64 bits here?");
return Select64(N, LateMask, InstCnt);
}
return nullptr;
}
void eraseMatchingBitGroups(function_ref<bool(const BitGroup &)> F) {
BitGroups.erase(remove_if(BitGroups, F), BitGroups.end());
}
SmallVector<ValueBit, 64> Bits;
bool NeedMask;
SmallVector<unsigned, 64> RLAmt;
SmallVector<BitGroup, 16> BitGroups;
DenseMap<std::pair<SDValue, unsigned>, ValueRotInfo> ValueRots;
SmallVector<ValueRotInfo, 16> ValueRotsVec;
SelectionDAG *CurDAG;
public:
BitPermutationSelector(SelectionDAG *DAG)
: CurDAG(DAG) {}
// Here we try to match complex bit permutations into a set of
// rotate-and-shift/shift/and/or instructions, using a set of heuristics
// known to produce optimal code for common cases (like i32 byte swapping).
SDNode *Select(SDNode *N) {
Memoizer.clear();
auto Result =
getValueBits(SDValue(N, 0), N->getValueType(0).getSizeInBits());
if (!Result.first)
return nullptr;
Bits = std::move(*Result.second);
LLVM_DEBUG(dbgs() << "Considering bit-permutation-based instruction"
" selection for: ");
LLVM_DEBUG(N->dump(CurDAG));
// Fill it RLAmt and set NeedMask.
computeRotationAmounts();
if (!NeedMask)
return Select(N, false);
// We currently have two techniques for handling results with zeros: early
// masking (the default) and late masking. Late masking is sometimes more
// efficient, but because the structure of the bit groups is different, it
// is hard to tell without generating both and comparing the results. With
// late masking, we ignore zeros in the resulting value when inserting each
// set of bit groups, and then mask in the zeros at the end. With early
// masking, we only insert the non-zero parts of the result at every step.
unsigned InstCnt = 0, InstCntLateMask = 0;
LLVM_DEBUG(dbgs() << "\tEarly masking:\n");
SDNode *RN = Select(N, false, &InstCnt);
LLVM_DEBUG(dbgs() << "\t\tisel would use " << InstCnt << " instructions\n");
LLVM_DEBUG(dbgs() << "\tLate masking:\n");
SDNode *RNLM = Select(N, true, &InstCntLateMask);
LLVM_DEBUG(dbgs() << "\t\tisel would use " << InstCntLateMask
<< " instructions\n");
if (InstCnt <= InstCntLateMask) {
LLVM_DEBUG(dbgs() << "\tUsing early-masking for isel\n");
return RN;
}
LLVM_DEBUG(dbgs() << "\tUsing late-masking for isel\n");
return RNLM;
}
};
class IntegerCompareEliminator {
SelectionDAG *CurDAG;
PPCDAGToDAGISel *S;
// Conversion type for interpreting results of a 32-bit instruction as
// a 64-bit value or vice versa.
enum ExtOrTruncConversion { Ext, Trunc };
// Modifiers to guide how an ISD::SETCC node's result is to be computed
// in a GPR.
// ZExtOrig - use the original condition code, zero-extend value
// ZExtInvert - invert the condition code, zero-extend value
// SExtOrig - use the original condition code, sign-extend value
// SExtInvert - invert the condition code, sign-extend value
enum SetccInGPROpts { ZExtOrig, ZExtInvert, SExtOrig, SExtInvert };
// Comparisons against zero to emit GPR code sequences for. Each of these
// sequences may need to be emitted for two or more equivalent patterns.
// For example (a >= 0) == (a > -1). The direction of the comparison (</>)
// matters as well as the extension type: sext (-1/0), zext (1/0).
// GEZExt - (zext (LHS >= 0))
// GESExt - (sext (LHS >= 0))
// LEZExt - (zext (LHS <= 0))
// LESExt - (sext (LHS <= 0))
enum ZeroCompare { GEZExt, GESExt, LEZExt, LESExt };
SDNode *tryEXTEND(SDNode *N);
SDNode *tryLogicOpOfCompares(SDNode *N);
SDValue computeLogicOpInGPR(SDValue LogicOp);
SDValue signExtendInputIfNeeded(SDValue Input);
SDValue zeroExtendInputIfNeeded(SDValue Input);
SDValue addExtOrTrunc(SDValue NatWidthRes, ExtOrTruncConversion Conv);
SDValue getCompoundZeroComparisonInGPR(SDValue LHS, SDLoc dl,
ZeroCompare CmpTy);
SDValue get32BitZExtCompare(SDValue LHS, SDValue RHS, ISD::CondCode CC,
int64_t RHSValue, SDLoc dl);
SDValue get32BitSExtCompare(SDValue LHS, SDValue RHS, ISD::CondCode CC,
int64_t RHSValue, SDLoc dl);
SDValue get64BitZExtCompare(SDValue LHS, SDValue RHS, ISD::CondCode CC,
int64_t RHSValue, SDLoc dl);
SDValue get64BitSExtCompare(SDValue LHS, SDValue RHS, ISD::CondCode CC,
int64_t RHSValue, SDLoc dl);
SDValue getSETCCInGPR(SDValue Compare, SetccInGPROpts ConvOpts);
public:
IntegerCompareEliminator(SelectionDAG *DAG,
PPCDAGToDAGISel *Sel) : CurDAG(DAG), S(Sel) {
assert(CurDAG->getTargetLoweringInfo()
.getPointerTy(CurDAG->getDataLayout()).getSizeInBits() == 64 &&
"Only expecting to use this on 64 bit targets.");
}
SDNode *Select(SDNode *N) {
if (CmpInGPR == ICGPR_None)
return nullptr;
switch (N->getOpcode()) {
default: break;
case ISD::ZERO_EXTEND:
if (CmpInGPR == ICGPR_Sext || CmpInGPR == ICGPR_SextI32 ||
CmpInGPR == ICGPR_SextI64)
return nullptr;
LLVM_FALLTHROUGH;
case ISD::SIGN_EXTEND:
if (CmpInGPR == ICGPR_Zext || CmpInGPR == ICGPR_ZextI32 ||
CmpInGPR == ICGPR_ZextI64)
return nullptr;
return tryEXTEND(N);
case ISD::AND:
case ISD::OR:
case ISD::XOR:
return tryLogicOpOfCompares(N);
}
return nullptr;
}
};
static bool isLogicOp(unsigned Opc) {
return Opc == ISD::AND || Opc == ISD::OR || Opc == ISD::XOR;
}
// The obvious case for wanting to keep the value in a GPR. Namely, the
// result of the comparison is actually needed in a GPR.
SDNode *IntegerCompareEliminator::tryEXTEND(SDNode *N) {
assert((N->getOpcode() == ISD::ZERO_EXTEND ||
N->getOpcode() == ISD::SIGN_EXTEND) &&
"Expecting a zero/sign extend node!");
SDValue WideRes;
// If we are zero-extending the result of a logical operation on i1
// values, we can keep the values in GPRs.
if (isLogicOp(N->getOperand(0).getOpcode()) &&
N->getOperand(0).getValueType() == MVT::i1 &&
N->getOpcode() == ISD::ZERO_EXTEND)
WideRes = computeLogicOpInGPR(N->getOperand(0));
else if (N->getOperand(0).getOpcode() != ISD::SETCC)
return nullptr;
else
WideRes =
getSETCCInGPR(N->getOperand(0),
N->getOpcode() == ISD::SIGN_EXTEND ?
SetccInGPROpts::SExtOrig : SetccInGPROpts::ZExtOrig);
if (!WideRes)
return nullptr;
SDLoc dl(N);
bool Input32Bit = WideRes.getValueType() == MVT::i32;
bool Output32Bit = N->getValueType(0) == MVT::i32;
NumSextSetcc += N->getOpcode() == ISD::SIGN_EXTEND ? 1 : 0;
NumZextSetcc += N->getOpcode() == ISD::SIGN_EXTEND ? 0 : 1;
SDValue ConvOp = WideRes;
if (Input32Bit != Output32Bit)
ConvOp = addExtOrTrunc(WideRes, Input32Bit ? ExtOrTruncConversion::Ext :
ExtOrTruncConversion::Trunc);
return ConvOp.getNode();
}
// Attempt to perform logical operations on the results of comparisons while
// keeping the values in GPRs. Without doing so, these would end up being
// lowered to CR-logical operations which suffer from significant latency and
// low ILP.
SDNode *IntegerCompareEliminator::tryLogicOpOfCompares(SDNode *N) {
if (N->getValueType(0) != MVT::i1)
return nullptr;
assert(isLogicOp(N->getOpcode()) &&
"Expected a logic operation on setcc results.");
SDValue LoweredLogical = computeLogicOpInGPR(SDValue(N, 0));
if (!LoweredLogical)
return nullptr;
SDLoc dl(N);
bool IsBitwiseNegate = LoweredLogical.getMachineOpcode() == PPC::XORI8;
unsigned SubRegToExtract = IsBitwiseNegate ? PPC::sub_eq : PPC::sub_gt;
SDValue CR0Reg = CurDAG->getRegister(PPC::CR0, MVT::i32);
SDValue LHS = LoweredLogical.getOperand(0);
SDValue RHS = LoweredLogical.getOperand(1);
SDValue WideOp;
SDValue OpToConvToRecForm;
// Look through any 32-bit to 64-bit implicit extend nodes to find the
// opcode that is input to the XORI.
if (IsBitwiseNegate &&
LoweredLogical.getOperand(0).getMachineOpcode() == PPC::INSERT_SUBREG)
OpToConvToRecForm = LoweredLogical.getOperand(0).getOperand(1);
else if (IsBitwiseNegate)
// If the input to the XORI isn't an extension, that's what we're after.
OpToConvToRecForm = LoweredLogical.getOperand(0);
else
// If this is not an XORI, it is a reg-reg logical op and we can convert
// it to record-form.
OpToConvToRecForm = LoweredLogical;
// Get the record-form version of the node we're looking to use to get the
// CR result from.
uint16_t NonRecOpc = OpToConvToRecForm.getMachineOpcode();
int NewOpc = PPCInstrInfo::getRecordFormOpcode(NonRecOpc);
// Convert the right node to record-form. This is either the logical we're
// looking at or it is the input node to the negation (if we're looking at
// a bitwise negation).
if (NewOpc != -1 && IsBitwiseNegate) {
// The input to the XORI has a record-form. Use it.
assert(LoweredLogical.getConstantOperandVal(1) == 1 &&
"Expected a PPC::XORI8 only for bitwise negation.");
// Emit the record-form instruction.
std::vector<SDValue> Ops;
for (int i = 0, e = OpToConvToRecForm.getNumOperands(); i < e; i++)
Ops.push_back(OpToConvToRecForm.getOperand(i));
WideOp =
SDValue(CurDAG->getMachineNode(NewOpc, dl,
OpToConvToRecForm.getValueType(),
MVT::Glue, Ops), 0);
} else {
assert((NewOpc != -1 || !IsBitwiseNegate) &&
"No record form available for AND8/OR8/XOR8?");
WideOp =
SDValue(CurDAG->getMachineNode(NewOpc == -1 ? PPC::ANDIo8 : NewOpc, dl,
MVT::i64, MVT::Glue, LHS, RHS), 0);
}
// Select this node to a single bit from CR0 set by the record-form node
// just created. For bitwise negation, use the EQ bit which is the equivalent
// of negating the result (i.e. it is a bit set when the result of the
// operation is zero).
SDValue SRIdxVal =
CurDAG->getTargetConstant(SubRegToExtract, dl, MVT::i32);
SDValue CRBit =
SDValue(CurDAG->getMachineNode(TargetOpcode::EXTRACT_SUBREG, dl,
MVT::i1, CR0Reg, SRIdxVal,
WideOp.getValue(1)), 0);
return CRBit.getNode();
}
// Lower a logical operation on i1 values into a GPR sequence if possible.
// The result can be kept in a GPR if requested.
// Three types of inputs can be handled:
// - SETCC
// - TRUNCATE
// - Logical operation (AND/OR/XOR)
// There is also a special case that is handled (namely a complement operation
// achieved with xor %a, -1).
SDValue IntegerCompareEliminator::computeLogicOpInGPR(SDValue LogicOp) {
assert(isLogicOp(LogicOp.getOpcode()) &&
"Can only handle logic operations here.");
assert(LogicOp.getValueType() == MVT::i1 &&
"Can only handle logic operations on i1 values here.");
SDLoc dl(LogicOp);
SDValue LHS, RHS;
// Special case: xor %a, -1
bool IsBitwiseNegation = isBitwiseNot(LogicOp);
// Produces a GPR sequence for each operand of the binary logic operation.
// For SETCC, it produces the respective comparison, for TRUNCATE it truncates
// the value in a GPR and for logic operations, it will recursively produce
// a GPR sequence for the operation.
auto getLogicOperand = [&] (SDValue Operand) -> SDValue {
unsigned OperandOpcode = Operand.getOpcode();
if (OperandOpcode == ISD::SETCC)
return getSETCCInGPR(Operand, SetccInGPROpts::ZExtOrig);
else if (OperandOpcode == ISD::TRUNCATE) {
SDValue InputOp = Operand.getOperand(0);
EVT InVT = InputOp.getValueType();
return SDValue(CurDAG->getMachineNode(InVT == MVT::i32 ? PPC::RLDICL_32 :
PPC::RLDICL, dl, InVT, InputOp,
S->getI64Imm(0, dl),
S->getI64Imm(63, dl)), 0);
} else if (isLogicOp(OperandOpcode))
return computeLogicOpInGPR(Operand);
return SDValue();
};
LHS = getLogicOperand(LogicOp.getOperand(0));
RHS = getLogicOperand(LogicOp.getOperand(1));
// If a GPR sequence can't be produced for the LHS we can't proceed.
// Not producing a GPR sequence for the RHS is only a problem if this isn't
// a bitwise negation operation.
if (!LHS || (!RHS && !IsBitwiseNegation))
return SDValue();
NumLogicOpsOnComparison++;
// We will use the inputs as 64-bit values.
if (LHS.getValueType() == MVT::i32)
LHS = addExtOrTrunc(LHS, ExtOrTruncConversion::Ext);
if (!IsBitwiseNegation && RHS.getValueType() == MVT::i32)
RHS = addExtOrTrunc(RHS, ExtOrTruncConversion::Ext);
unsigned NewOpc;
switch (LogicOp.getOpcode()) {
default: llvm_unreachable("Unknown logic operation.");
case ISD::AND: NewOpc = PPC::AND8; break;
case ISD::OR: NewOpc = PPC::OR8; break;
case ISD::XOR: NewOpc = PPC::XOR8; break;
}
if (IsBitwiseNegation) {
RHS = S->getI64Imm(1, dl);
NewOpc = PPC::XORI8;
}
return SDValue(CurDAG->getMachineNode(NewOpc, dl, MVT::i64, LHS, RHS), 0);
}
/// If the value isn't guaranteed to be sign-extended to 64-bits, extend it.
/// Otherwise just reinterpret it as a 64-bit value.
/// Useful when emitting comparison code for 32-bit values without using
/// the compare instruction (which only considers the lower 32-bits).
SDValue IntegerCompareEliminator::signExtendInputIfNeeded(SDValue Input) {
assert(Input.getValueType() == MVT::i32 &&
"Can only sign-extend 32-bit values here.");
unsigned Opc = Input.getOpcode();
// The value was sign extended and then truncated to 32-bits. No need to
// sign extend it again.
if (Opc == ISD::TRUNCATE &&
(Input.getOperand(0).getOpcode() == ISD::AssertSext ||
Input.getOperand(0).getOpcode() == ISD::SIGN_EXTEND))
return addExtOrTrunc(Input, ExtOrTruncConversion::Ext);
LoadSDNode *InputLoad = dyn_cast<LoadSDNode>(Input);
// The input is a sign-extending load. All ppc sign-extending loads
// sign-extend to the full 64-bits.
if (InputLoad && InputLoad->getExtensionType() == ISD::SEXTLOAD)
return addExtOrTrunc(Input, ExtOrTruncConversion::Ext);
ConstantSDNode *InputConst = dyn_cast<ConstantSDNode>(Input);
// We don't sign-extend constants.
if (InputConst)
return addExtOrTrunc(Input, ExtOrTruncConversion::Ext);
SDLoc dl(Input);
SignExtensionsAdded++;
return SDValue(CurDAG->getMachineNode(PPC::EXTSW_32_64, dl,
MVT::i64, Input), 0);
}
/// If the value isn't guaranteed to be zero-extended to 64-bits, extend it.
/// Otherwise just reinterpret it as a 64-bit value.
/// Useful when emitting comparison code for 32-bit values without using
/// the compare instruction (which only considers the lower 32-bits).
SDValue IntegerCompareEliminator::zeroExtendInputIfNeeded(SDValue Input) {
assert(Input.getValueType() == MVT::i32 &&
"Can only zero-extend 32-bit values here.");
unsigned Opc = Input.getOpcode();
// The only condition under which we can omit the actual extend instruction:
// - The value is a positive constant
// - The value comes from a load that isn't a sign-extending load
// An ISD::TRUNCATE needs to be zero-extended unless it is fed by a zext.
bool IsTruncateOfZExt = Opc == ISD::TRUNCATE &&
(Input.getOperand(0).getOpcode() == ISD::AssertZext ||
Input.getOperand(0).getOpcode() == ISD::ZERO_EXTEND);
if (IsTruncateOfZExt)
return addExtOrTrunc(Input, ExtOrTruncConversion::Ext);
ConstantSDNode *InputConst = dyn_cast<ConstantSDNode>(Input);
if (InputConst && InputConst->getSExtValue() >= 0)
return addExtOrTrunc(Input, ExtOrTruncConversion::Ext);
LoadSDNode *InputLoad = dyn_cast<LoadSDNode>(Input);
// The input is a load that doesn't sign-extend (it will be zero-extended).
if (InputLoad && InputLoad->getExtensionType() != ISD::SEXTLOAD)
return addExtOrTrunc(Input, ExtOrTruncConversion::Ext);
// None of the above, need to zero-extend.
SDLoc dl(Input);
ZeroExtensionsAdded++;
return SDValue(CurDAG->getMachineNode(PPC::RLDICL_32_64, dl, MVT::i64, Input,
S->getI64Imm(0, dl),
S->getI64Imm(32, dl)), 0);
}
// Handle a 32-bit value in a 64-bit register and vice-versa. These are of
// course not actual zero/sign extensions that will generate machine code,
// they're just a way to reinterpret a 32 bit value in a register as a
// 64 bit value and vice-versa.
SDValue IntegerCompareEliminator::addExtOrTrunc(SDValue NatWidthRes,
ExtOrTruncConversion Conv) {
SDLoc dl(NatWidthRes);
// For reinterpreting 32-bit values as 64 bit values, we generate
// INSERT_SUBREG IMPLICIT_DEF:i64, <input>, TargetConstant:i32<1>
if (Conv == ExtOrTruncConversion::Ext) {
SDValue ImDef(CurDAG->getMachineNode(PPC::IMPLICIT_DEF, dl, MVT::i64), 0);
SDValue SubRegIdx =
CurDAG->getTargetConstant(PPC::sub_32, dl, MVT::i32);
return SDValue(CurDAG->getMachineNode(PPC::INSERT_SUBREG, dl, MVT::i64,
ImDef, NatWidthRes, SubRegIdx), 0);
}
assert(Conv == ExtOrTruncConversion::Trunc &&
"Unknown convertion between 32 and 64 bit values.");
// For reinterpreting 64-bit values as 32-bit values, we just need to
// EXTRACT_SUBREG (i.e. extract the low word).
SDValue SubRegIdx =
CurDAG->getTargetConstant(PPC::sub_32, dl, MVT::i32);
return SDValue(CurDAG->getMachineNode(PPC::EXTRACT_SUBREG, dl, MVT::i32,
NatWidthRes, SubRegIdx), 0);
}
// Produce a GPR sequence for compound comparisons (<=, >=) against zero.
// Handle both zero-extensions and sign-extensions.
SDValue
IntegerCompareEliminator::getCompoundZeroComparisonInGPR(SDValue LHS, SDLoc dl,
ZeroCompare CmpTy) {
EVT InVT = LHS.getValueType();
bool Is32Bit = InVT == MVT::i32;
SDValue ToExtend;
// Produce the value that needs to be either zero or sign extended.
switch (CmpTy) {
case ZeroCompare::GEZExt:
case ZeroCompare::GESExt:
ToExtend = SDValue(CurDAG->getMachineNode(Is32Bit ? PPC::NOR : PPC::NOR8,
dl, InVT, LHS, LHS), 0);
break;
case ZeroCompare::LEZExt:
case ZeroCompare::LESExt: {
if (Is32Bit) {
// Upper 32 bits cannot be undefined for this sequence.
LHS = signExtendInputIfNeeded(LHS);
SDValue Neg =
SDValue(CurDAG->getMachineNode(PPC::NEG8, dl, MVT::i64, LHS), 0);
ToExtend =
SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64,
Neg, S->getI64Imm(1, dl),
S->getI64Imm(63, dl)), 0);
} else {
SDValue Addi =
SDValue(CurDAG->getMachineNode(PPC::ADDI8, dl, MVT::i64, LHS,
S->getI64Imm(~0ULL, dl)), 0);
ToExtend = SDValue(CurDAG->getMachineNode(PPC::OR8, dl, MVT::i64,
Addi, LHS), 0);
}
break;
}
}
// For 64-bit sequences, the extensions are the same for the GE/LE cases.
if (!Is32Bit &&
(CmpTy == ZeroCompare::GEZExt || CmpTy == ZeroCompare::LEZExt))
return SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64,
ToExtend, S->getI64Imm(1, dl),
S->getI64Imm(63, dl)), 0);
if (!Is32Bit &&
(CmpTy == ZeroCompare::GESExt || CmpTy == ZeroCompare::LESExt))
return SDValue(CurDAG->getMachineNode(PPC::SRADI, dl, MVT::i64, ToExtend,
S->getI64Imm(63, dl)), 0);
assert(Is32Bit && "Should have handled the 32-bit sequences above.");
// For 32-bit sequences, the extensions differ between GE/LE cases.
switch (CmpTy) {
case ZeroCompare::GEZExt: {
SDValue ShiftOps[] = { ToExtend, S->getI32Imm(1, dl), S->getI32Imm(31, dl),
S->getI32Imm(31, dl) };
return SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32,
ShiftOps), 0);
}
case ZeroCompare::GESExt:
return SDValue(CurDAG->getMachineNode(PPC::SRAWI, dl, MVT::i32, ToExtend,
S->getI32Imm(31, dl)), 0);
case ZeroCompare::LEZExt:
return SDValue(CurDAG->getMachineNode(PPC::XORI8, dl, MVT::i64, ToExtend,
S->getI32Imm(1, dl)), 0);
case ZeroCompare::LESExt:
return SDValue(CurDAG->getMachineNode(PPC::ADDI8, dl, MVT::i64, ToExtend,
S->getI32Imm(-1, dl)), 0);
}
// The above case covers all the enumerators so it can't have a default clause
// to avoid compiler warnings.
llvm_unreachable("Unknown zero-comparison type.");
}
/// Produces a zero-extended result of comparing two 32-bit values according to
/// the passed condition code.
SDValue
IntegerCompareEliminator::get32BitZExtCompare(SDValue LHS, SDValue RHS,
ISD::CondCode CC,
int64_t RHSValue, SDLoc dl) {
if (CmpInGPR == ICGPR_I64 || CmpInGPR == ICGPR_SextI64 ||
CmpInGPR == ICGPR_ZextI64 || CmpInGPR == ICGPR_Sext)
return SDValue();
bool IsRHSZero = RHSValue == 0;
bool IsRHSOne = RHSValue == 1;
bool IsRHSNegOne = RHSValue == -1LL;
switch (CC) {
default: return SDValue();
case ISD::SETEQ: {
// (zext (setcc %a, %b, seteq)) -> (lshr (cntlzw (xor %a, %b)), 5)
// (zext (setcc %a, 0, seteq)) -> (lshr (cntlzw %a), 5)
SDValue Xor = IsRHSZero ? LHS :
SDValue(CurDAG->getMachineNode(PPC::XOR, dl, MVT::i32, LHS, RHS), 0);
SDValue Clz =
SDValue(CurDAG->getMachineNode(PPC::CNTLZW, dl, MVT::i32, Xor), 0);
SDValue ShiftOps[] = { Clz, S->getI32Imm(27, dl), S->getI32Imm(5, dl),
S->getI32Imm(31, dl) };
return SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32,
ShiftOps), 0);
}
case ISD::SETNE: {
// (zext (setcc %a, %b, setne)) -> (xor (lshr (cntlzw (xor %a, %b)), 5), 1)
// (zext (setcc %a, 0, setne)) -> (xor (lshr (cntlzw %a), 5), 1)
SDValue Xor = IsRHSZero ? LHS :
SDValue(CurDAG->getMachineNode(PPC::XOR, dl, MVT::i32, LHS, RHS), 0);
SDValue Clz =
SDValue(CurDAG->getMachineNode(PPC::CNTLZW, dl, MVT::i32, Xor), 0);
SDValue ShiftOps[] = { Clz, S->getI32Imm(27, dl), S->getI32Imm(5, dl),
S->getI32Imm(31, dl) };
SDValue Shift =
SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, ShiftOps), 0);
return SDValue(CurDAG->getMachineNode(PPC::XORI, dl, MVT::i32, Shift,
S->getI32Imm(1, dl)), 0);
}
case ISD::SETGE: {
// (zext (setcc %a, %b, setge)) -> (xor (lshr (sub %a, %b), 63), 1)
// (zext (setcc %a, 0, setge)) -> (lshr (~ %a), 31)
if(IsRHSZero)
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::GEZExt);
// Not a special case (i.e. RHS == 0). Handle (%a >= %b) as (%b <= %a)
// by swapping inputs and falling through.
std::swap(LHS, RHS);
ConstantSDNode *RHSConst = dyn_cast<ConstantSDNode>(RHS);
IsRHSZero = RHSConst && RHSConst->isNullValue();
LLVM_FALLTHROUGH;
}
case ISD::SETLE: {
if (CmpInGPR == ICGPR_NonExtIn)
return SDValue();
// (zext (setcc %a, %b, setle)) -> (xor (lshr (sub %b, %a), 63), 1)
// (zext (setcc %a, 0, setle)) -> (xor (lshr (- %a), 63), 1)
if(IsRHSZero) {
if (CmpInGPR == ICGPR_NonExtIn)
return SDValue();
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::LEZExt);
}
// The upper 32-bits of the register can't be undefined for this sequence.
LHS = signExtendInputIfNeeded(LHS);
RHS = signExtendInputIfNeeded(RHS);
SDValue Sub =
SDValue(CurDAG->getMachineNode(PPC::SUBF8, dl, MVT::i64, LHS, RHS), 0);
SDValue Shift =
SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64, Sub,
S->getI64Imm(1, dl), S->getI64Imm(63, dl)),
0);
return
SDValue(CurDAG->getMachineNode(PPC::XORI8, dl,
MVT::i64, Shift, S->getI32Imm(1, dl)), 0);
}
case ISD::SETGT: {
// (zext (setcc %a, %b, setgt)) -> (lshr (sub %b, %a), 63)
// (zext (setcc %a, -1, setgt)) -> (lshr (~ %a), 31)
// (zext (setcc %a, 0, setgt)) -> (lshr (- %a), 63)
// Handle SETLT -1 (which is equivalent to SETGE 0).
if (IsRHSNegOne)
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::GEZExt);
if (IsRHSZero) {
if (CmpInGPR == ICGPR_NonExtIn)
return SDValue();
// The upper 32-bits of the register can't be undefined for this sequence.
LHS = signExtendInputIfNeeded(LHS);
RHS = signExtendInputIfNeeded(RHS);
SDValue Neg =
SDValue(CurDAG->getMachineNode(PPC::NEG8, dl, MVT::i64, LHS), 0);
return SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64,
Neg, S->getI32Imm(1, dl), S->getI32Imm(63, dl)), 0);
}
// Not a special case (i.e. RHS == 0 or RHS == -1). Handle (%a > %b) as
// (%b < %a) by swapping inputs and falling through.
std::swap(LHS, RHS);
ConstantSDNode *RHSConst = dyn_cast<ConstantSDNode>(RHS);
IsRHSZero = RHSConst && RHSConst->isNullValue();
IsRHSOne = RHSConst && RHSConst->getSExtValue() == 1;
LLVM_FALLTHROUGH;
}
case ISD::SETLT: {
// (zext (setcc %a, %b, setlt)) -> (lshr (sub %a, %b), 63)
// (zext (setcc %a, 1, setlt)) -> (xor (lshr (- %a), 63), 1)
// (zext (setcc %a, 0, setlt)) -> (lshr %a, 31)
// Handle SETLT 1 (which is equivalent to SETLE 0).
if (IsRHSOne) {
if (CmpInGPR == ICGPR_NonExtIn)
return SDValue();
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::LEZExt);
}
if (IsRHSZero) {
SDValue ShiftOps[] = { LHS, S->getI32Imm(1, dl), S->getI32Imm(31, dl),
S->getI32Imm(31, dl) };
return SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32,
ShiftOps), 0);
}
if (CmpInGPR == ICGPR_NonExtIn)
return SDValue();
// The upper 32-bits of the register can't be undefined for this sequence.
LHS = signExtendInputIfNeeded(LHS);
RHS = signExtendInputIfNeeded(RHS);
SDValue SUBFNode =
SDValue(CurDAG->getMachineNode(PPC::SUBF8, dl, MVT::i64, RHS, LHS), 0);
return SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64,
SUBFNode, S->getI64Imm(1, dl),
S->getI64Imm(63, dl)), 0);
}
case ISD::SETUGE:
// (zext (setcc %a, %b, setuge)) -> (xor (lshr (sub %b, %a), 63), 1)
// (zext (setcc %a, %b, setule)) -> (xor (lshr (sub %a, %b), 63), 1)
std::swap(LHS, RHS);
LLVM_FALLTHROUGH;
case ISD::SETULE: {
if (CmpInGPR == ICGPR_NonExtIn)
return SDValue();
// The upper 32-bits of the register can't be undefined for this sequence.
LHS = zeroExtendInputIfNeeded(LHS);
RHS = zeroExtendInputIfNeeded(RHS);
SDValue Subtract =
SDValue(CurDAG->getMachineNode(PPC::SUBF8, dl, MVT::i64, LHS, RHS), 0);
SDValue SrdiNode =
SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64,
Subtract, S->getI64Imm(1, dl),
S->getI64Imm(63, dl)), 0);
return SDValue(CurDAG->getMachineNode(PPC::XORI8, dl, MVT::i64, SrdiNode,
S->getI32Imm(1, dl)), 0);
}
case ISD::SETUGT:
// (zext (setcc %a, %b, setugt)) -> (lshr (sub %b, %a), 63)
// (zext (setcc %a, %b, setult)) -> (lshr (sub %a, %b), 63)
std::swap(LHS, RHS);
LLVM_FALLTHROUGH;
case ISD::SETULT: {
if (CmpInGPR == ICGPR_NonExtIn)
return SDValue();
// The upper 32-bits of the register can't be undefined for this sequence.
LHS = zeroExtendInputIfNeeded(LHS);
RHS = zeroExtendInputIfNeeded(RHS);
SDValue Subtract =
SDValue(CurDAG->getMachineNode(PPC::SUBF8, dl, MVT::i64, RHS, LHS), 0);
return SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64,
Subtract, S->getI64Imm(1, dl),
S->getI64Imm(63, dl)), 0);
}
}
}
/// Produces a sign-extended result of comparing two 32-bit values according to
/// the passed condition code.
SDValue
IntegerCompareEliminator::get32BitSExtCompare(SDValue LHS, SDValue RHS,
ISD::CondCode CC,
int64_t RHSValue, SDLoc dl) {
if (CmpInGPR == ICGPR_I64 || CmpInGPR == ICGPR_SextI64 ||
CmpInGPR == ICGPR_ZextI64 || CmpInGPR == ICGPR_Zext)
return SDValue();
bool IsRHSZero = RHSValue == 0;
bool IsRHSOne = RHSValue == 1;
bool IsRHSNegOne = RHSValue == -1LL;
switch (CC) {
default: return SDValue();
case ISD::SETEQ: {
// (sext (setcc %a, %b, seteq)) ->
// (ashr (shl (ctlz (xor %a, %b)), 58), 63)
// (sext (setcc %a, 0, seteq)) ->
// (ashr (shl (ctlz %a), 58), 63)
SDValue CountInput = IsRHSZero ? LHS :
SDValue(CurDAG->getMachineNode(PPC::XOR, dl, MVT::i32, LHS, RHS), 0);
SDValue Cntlzw =
SDValue(CurDAG->getMachineNode(PPC::CNTLZW, dl, MVT::i32, CountInput), 0);
SDValue SHLOps[] = { Cntlzw, S->getI32Imm(27, dl),
S->getI32Imm(5, dl), S->getI32Imm(31, dl) };
SDValue Slwi =
SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, SHLOps), 0);
return SDValue(CurDAG->getMachineNode(PPC::NEG, dl, MVT::i32, Slwi), 0);
}
case ISD::SETNE: {
// Bitwise xor the operands, count leading zeros, shift right by 5 bits and
// flip the bit, finally take 2's complement.
// (sext (setcc %a, %b, setne)) ->
// (neg (xor (lshr (ctlz (xor %a, %b)), 5), 1))
// Same as above, but the first xor is not needed.
// (sext (setcc %a, 0, setne)) ->
// (neg (xor (lshr (ctlz %a), 5), 1))
SDValue Xor = IsRHSZero ? LHS :
SDValue(CurDAG->getMachineNode(PPC::XOR, dl, MVT::i32, LHS, RHS), 0);
SDValue Clz =
SDValue(CurDAG->getMachineNode(PPC::CNTLZW, dl, MVT::i32, Xor), 0);
SDValue ShiftOps[] =
{ Clz, S->getI32Imm(27, dl), S->getI32Imm(5, dl), S->getI32Imm(31, dl) };
SDValue Shift =
SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, ShiftOps), 0);
SDValue Xori =
SDValue(CurDAG->getMachineNode(PPC::XORI, dl, MVT::i32, Shift,
S->getI32Imm(1, dl)), 0);
return SDValue(CurDAG->getMachineNode(PPC::NEG, dl, MVT::i32, Xori), 0);
}
case ISD::SETGE: {
// (sext (setcc %a, %b, setge)) -> (add (lshr (sub %a, %b), 63), -1)
// (sext (setcc %a, 0, setge)) -> (ashr (~ %a), 31)
if (IsRHSZero)
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::GESExt);
// Not a special case (i.e. RHS == 0). Handle (%a >= %b) as (%b <= %a)
// by swapping inputs and falling through.
std::swap(LHS, RHS);
ConstantSDNode *RHSConst = dyn_cast<ConstantSDNode>(RHS);
IsRHSZero = RHSConst && RHSConst->isNullValue();
LLVM_FALLTHROUGH;
}
case ISD::SETLE: {
if (CmpInGPR == ICGPR_NonExtIn)
return SDValue();
// (sext (setcc %a, %b, setge)) -> (add (lshr (sub %b, %a), 63), -1)
// (sext (setcc %a, 0, setle)) -> (add (lshr (- %a), 63), -1)
if (IsRHSZero)
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::LESExt);
// The upper 32-bits of the register can't be undefined for this sequence.
LHS = signExtendInputIfNeeded(LHS);
RHS = signExtendInputIfNeeded(RHS);
SDValue SUBFNode =
SDValue(CurDAG->getMachineNode(PPC::SUBF8, dl, MVT::i64, MVT::Glue,
LHS, RHS), 0);
SDValue Srdi =
SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64,
SUBFNode, S->getI64Imm(1, dl),
S->getI64Imm(63, dl)), 0);
return SDValue(CurDAG->getMachineNode(PPC::ADDI8, dl, MVT::i64, Srdi,
S->getI32Imm(-1, dl)), 0);
}
case ISD::SETGT: {
// (sext (setcc %a, %b, setgt)) -> (ashr (sub %b, %a), 63)
// (sext (setcc %a, -1, setgt)) -> (ashr (~ %a), 31)
// (sext (setcc %a, 0, setgt)) -> (ashr (- %a), 63)
if (IsRHSNegOne)
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::GESExt);
if (IsRHSZero) {
if (CmpInGPR == ICGPR_NonExtIn)
return SDValue();
// The upper 32-bits of the register can't be undefined for this sequence.
LHS = signExtendInputIfNeeded(LHS);
RHS = signExtendInputIfNeeded(RHS);
SDValue Neg =
SDValue(CurDAG->getMachineNode(PPC::NEG8, dl, MVT::i64, LHS), 0);
return SDValue(CurDAG->getMachineNode(PPC::SRADI, dl, MVT::i64, Neg,
S->getI64Imm(63, dl)), 0);
}
// Not a special case (i.e. RHS == 0 or RHS == -1). Handle (%a > %b) as
// (%b < %a) by swapping inputs and falling through.
std::swap(LHS, RHS);
ConstantSDNode *RHSConst = dyn_cast<ConstantSDNode>(RHS);
IsRHSZero = RHSConst && RHSConst->isNullValue();
IsRHSOne = RHSConst && RHSConst->getSExtValue() == 1;
LLVM_FALLTHROUGH;
}
case ISD::SETLT: {
// (sext (setcc %a, %b, setgt)) -> (ashr (sub %a, %b), 63)
// (sext (setcc %a, 1, setgt)) -> (add (lshr (- %a), 63), -1)
// (sext (setcc %a, 0, setgt)) -> (ashr %a, 31)
if (IsRHSOne) {
if (CmpInGPR == ICGPR_NonExtIn)
return SDValue();
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::LESExt);
}
if (IsRHSZero)
return SDValue(CurDAG->getMachineNode(PPC::SRAWI, dl, MVT::i32, LHS,
S->getI32Imm(31, dl)), 0);
if (CmpInGPR == ICGPR_NonExtIn)
return SDValue();
// The upper 32-bits of the register can't be undefined for this sequence.
LHS = signExtendInputIfNeeded(LHS);
RHS = signExtendInputIfNeeded(RHS);
SDValue SUBFNode =
SDValue(CurDAG->getMachineNode(PPC::SUBF8, dl, MVT::i64, RHS, LHS), 0);
return SDValue(CurDAG->getMachineNode(PPC::SRADI, dl, MVT::i64,
SUBFNode, S->getI64Imm(63, dl)), 0);
}
case ISD::SETUGE:
// (sext (setcc %a, %b, setuge)) -> (add (lshr (sub %a, %b), 63), -1)
// (sext (setcc %a, %b, setule)) -> (add (lshr (sub %b, %a), 63), -1)
std::swap(LHS, RHS);
LLVM_FALLTHROUGH;
case ISD::SETULE: {
if (CmpInGPR == ICGPR_NonExtIn)
return SDValue();
// The upper 32-bits of the register can't be undefined for this sequence.
LHS = zeroExtendInputIfNeeded(LHS);
RHS = zeroExtendInputIfNeeded(RHS);
SDValue Subtract =
SDValue(CurDAG->getMachineNode(PPC::SUBF8, dl, MVT::i64, LHS, RHS), 0);
SDValue Shift =
SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64, Subtract,
S->getI32Imm(1, dl), S->getI32Imm(63,dl)),
0);
return SDValue(CurDAG->getMachineNode(PPC::ADDI8, dl, MVT::i64, Shift,
S->getI32Imm(-1, dl)), 0);
}
case ISD::SETUGT:
// (sext (setcc %a, %b, setugt)) -> (ashr (sub %b, %a), 63)
// (sext (setcc %a, %b, setugt)) -> (ashr (sub %a, %b), 63)
std::swap(LHS, RHS);
LLVM_FALLTHROUGH;
case ISD::SETULT: {
if (CmpInGPR == ICGPR_NonExtIn)
return SDValue();
// The upper 32-bits of the register can't be undefined for this sequence.
LHS = zeroExtendInputIfNeeded(LHS);
RHS = zeroExtendInputIfNeeded(RHS);
SDValue Subtract =
SDValue(CurDAG->getMachineNode(PPC::SUBF8, dl, MVT::i64, RHS, LHS), 0);
return SDValue(CurDAG->getMachineNode(PPC::SRADI, dl, MVT::i64,
Subtract, S->getI64Imm(63, dl)), 0);
}
}
}
/// Produces a zero-extended result of comparing two 64-bit values according to
/// the passed condition code.
SDValue
IntegerCompareEliminator::get64BitZExtCompare(SDValue LHS, SDValue RHS,
ISD::CondCode CC,
int64_t RHSValue, SDLoc dl) {
if (CmpInGPR == ICGPR_I32 || CmpInGPR == ICGPR_SextI32 ||
CmpInGPR == ICGPR_ZextI32 || CmpInGPR == ICGPR_Sext)
return SDValue();
bool IsRHSZero = RHSValue == 0;
bool IsRHSOne = RHSValue == 1;
bool IsRHSNegOne = RHSValue == -1LL;
switch (CC) {
default: return SDValue();
case ISD::SETEQ: {
// (zext (setcc %a, %b, seteq)) -> (lshr (ctlz (xor %a, %b)), 6)
// (zext (setcc %a, 0, seteq)) -> (lshr (ctlz %a), 6)
SDValue Xor = IsRHSZero ? LHS :
SDValue(CurDAG->getMachineNode(PPC::XOR8, dl, MVT::i64, LHS, RHS), 0);
SDValue Clz =
SDValue(CurDAG->getMachineNode(PPC::CNTLZD, dl, MVT::i64, Xor), 0);
return SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64, Clz,
S->getI64Imm(58, dl),
S->getI64Imm(63, dl)), 0);
}
case ISD::SETNE: {
// {addc.reg, addc.CA} = (addcarry (xor %a, %b), -1)
// (zext (setcc %a, %b, setne)) -> (sube addc.reg, addc.reg, addc.CA)
// {addcz.reg, addcz.CA} = (addcarry %a, -1)
// (zext (setcc %a, 0, setne)) -> (sube addcz.reg, addcz.reg, addcz.CA)
SDValue Xor = IsRHSZero ? LHS :
SDValue(CurDAG->getMachineNode(PPC::XOR8, dl, MVT::i64, LHS, RHS), 0);
SDValue AC =
SDValue(CurDAG->getMachineNode(PPC::ADDIC8, dl, MVT::i64, MVT::Glue,
Xor, S->getI32Imm(~0U, dl)), 0);
return SDValue(CurDAG->getMachineNode(PPC::SUBFE8, dl, MVT::i64, AC,
Xor, AC.getValue(1)), 0);
}
case ISD::SETGE: {
// {subc.reg, subc.CA} = (subcarry %a, %b)
// (zext (setcc %a, %b, setge)) ->
// (adde (lshr %b, 63), (ashr %a, 63), subc.CA)
// (zext (setcc %a, 0, setge)) -> (lshr (~ %a), 63)
if (IsRHSZero)
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::GEZExt);
std::swap(LHS, RHS);
ConstantSDNode *RHSConst = dyn_cast<ConstantSDNode>(RHS);
IsRHSZero = RHSConst && RHSConst->isNullValue();
LLVM_FALLTHROUGH;
}
case ISD::SETLE: {
// {subc.reg, subc.CA} = (subcarry %b, %a)
// (zext (setcc %a, %b, setge)) ->
// (adde (lshr %a, 63), (ashr %b, 63), subc.CA)
// (zext (setcc %a, 0, setge)) -> (lshr (or %a, (add %a, -1)), 63)
if (IsRHSZero)
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::LEZExt);
SDValue ShiftL =
SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64, LHS,
S->getI64Imm(1, dl),
S->getI64Imm(63, dl)), 0);
SDValue ShiftR =
SDValue(CurDAG->getMachineNode(PPC::SRADI, dl, MVT::i64, RHS,
S->getI64Imm(63, dl)), 0);
SDValue SubtractCarry =
SDValue(CurDAG->getMachineNode(PPC::SUBFC8, dl, MVT::i64, MVT::Glue,
LHS, RHS), 1);
return SDValue(CurDAG->getMachineNode(PPC::ADDE8, dl, MVT::i64, MVT::Glue,
ShiftR, ShiftL, SubtractCarry), 0);
}
case ISD::SETGT: {
// {subc.reg, subc.CA} = (subcarry %b, %a)
// (zext (setcc %a, %b, setgt)) ->
// (xor (adde (lshr %a, 63), (ashr %b, 63), subc.CA), 1)
// (zext (setcc %a, 0, setgt)) -> (lshr (nor (add %a, -1), %a), 63)
if (IsRHSNegOne)
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::GEZExt);
if (IsRHSZero) {
SDValue Addi =
SDValue(CurDAG->getMachineNode(PPC::ADDI8, dl, MVT::i64, LHS,
S->getI64Imm(~0ULL, dl)), 0);
SDValue Nor =
SDValue(CurDAG->getMachineNode(PPC::NOR8, dl, MVT::i64, Addi, LHS), 0);
return SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64, Nor,
S->getI64Imm(1, dl),
S->getI64Imm(63, dl)), 0);
}
std::swap(LHS, RHS);
ConstantSDNode *RHSConst = dyn_cast<ConstantSDNode>(RHS);
IsRHSZero = RHSConst && RHSConst->isNullValue();
IsRHSOne = RHSConst && RHSConst->getSExtValue() == 1;
LLVM_FALLTHROUGH;
}
case ISD::SETLT: {
// {subc.reg, subc.CA} = (subcarry %a, %b)
// (zext (setcc %a, %b, setlt)) ->
// (xor (adde (lshr %b, 63), (ashr %a, 63), subc.CA), 1)
// (zext (setcc %a, 0, setlt)) -> (lshr %a, 63)
if (IsRHSOne)
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::LEZExt);
if (IsRHSZero)
return SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64, LHS,
S->getI64Imm(1, dl),
S->getI64Imm(63, dl)), 0);
SDValue SRADINode =
SDValue(CurDAG->getMachineNode(PPC::SRADI, dl, MVT::i64,
LHS, S->getI64Imm(63, dl)), 0);
SDValue SRDINode =
SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64,
RHS, S->getI64Imm(1, dl),
S->getI64Imm(63, dl)), 0);
SDValue SUBFC8Carry =
SDValue(CurDAG->getMachineNode(PPC::SUBFC8, dl, MVT::i64, MVT::Glue,
RHS, LHS), 1);
SDValue ADDE8Node =
SDValue(CurDAG->getMachineNode(PPC::ADDE8, dl, MVT::i64, MVT::Glue,
SRDINode, SRADINode, SUBFC8Carry), 0);
return SDValue(CurDAG->getMachineNode(PPC::XORI8, dl, MVT::i64,
ADDE8Node, S->getI64Imm(1, dl)), 0);
}
case ISD::SETUGE:
// {subc.reg, subc.CA} = (subcarry %a, %b)
// (zext (setcc %a, %b, setuge)) -> (add (sube %b, %b, subc.CA), 1)
std::swap(LHS, RHS);
LLVM_FALLTHROUGH;
case ISD::SETULE: {
// {subc.reg, subc.CA} = (subcarry %b, %a)
// (zext (setcc %a, %b, setule)) -> (add (sube %a, %a, subc.CA), 1)
SDValue SUBFC8Carry =
SDValue(CurDAG->getMachineNode(PPC::SUBFC8, dl, MVT::i64, MVT::Glue,
LHS, RHS), 1);
SDValue SUBFE8Node =
SDValue(CurDAG->getMachineNode(PPC::SUBFE8, dl, MVT::i64, MVT::Glue,
LHS, LHS, SUBFC8Carry), 0);
return SDValue(CurDAG->getMachineNode(PPC::ADDI8, dl, MVT::i64,
SUBFE8Node, S->getI64Imm(1, dl)), 0);
}
case ISD::SETUGT:
// {subc.reg, subc.CA} = (subcarry %b, %a)
// (zext (setcc %a, %b, setugt)) -> -(sube %b, %b, subc.CA)
std::swap(LHS, RHS);
LLVM_FALLTHROUGH;
case ISD::SETULT: {
// {subc.reg, subc.CA} = (subcarry %a, %b)
// (zext (setcc %a, %b, setult)) -> -(sube %a, %a, subc.CA)
SDValue SubtractCarry =
SDValue(CurDAG->getMachineNode(PPC::SUBFC8, dl, MVT::i64, MVT::Glue,
RHS, LHS), 1);
SDValue ExtSub =
SDValue(CurDAG->getMachineNode(PPC::SUBFE8, dl, MVT::i64,
LHS, LHS, SubtractCarry), 0);
return SDValue(CurDAG->getMachineNode(PPC::NEG8, dl, MVT::i64,
ExtSub), 0);
}
}
}
/// Produces a sign-extended result of comparing two 64-bit values according to
/// the passed condition code.
SDValue
IntegerCompareEliminator::get64BitSExtCompare(SDValue LHS, SDValue RHS,
ISD::CondCode CC,
int64_t RHSValue, SDLoc dl) {
if (CmpInGPR == ICGPR_I32 || CmpInGPR == ICGPR_SextI32 ||
CmpInGPR == ICGPR_ZextI32 || CmpInGPR == ICGPR_Zext)
return SDValue();
bool IsRHSZero = RHSValue == 0;
bool IsRHSOne = RHSValue == 1;
bool IsRHSNegOne = RHSValue == -1LL;
switch (CC) {
default: return SDValue();
case ISD::SETEQ: {
// {addc.reg, addc.CA} = (addcarry (xor %a, %b), -1)
// (sext (setcc %a, %b, seteq)) -> (sube addc.reg, addc.reg, addc.CA)
// {addcz.reg, addcz.CA} = (addcarry %a, -1)
// (sext (setcc %a, 0, seteq)) -> (sube addcz.reg, addcz.reg, addcz.CA)
SDValue AddInput = IsRHSZero ? LHS :
SDValue(CurDAG->getMachineNode(PPC::XOR8, dl, MVT::i64, LHS, RHS), 0);
SDValue Addic =
SDValue(CurDAG->getMachineNode(PPC::ADDIC8, dl, MVT::i64, MVT::Glue,
AddInput, S->getI32Imm(~0U, dl)), 0);
return SDValue(CurDAG->getMachineNode(PPC::SUBFE8, dl, MVT::i64, Addic,
Addic, Addic.getValue(1)), 0);
}
case ISD::SETNE: {
// {subfc.reg, subfc.CA} = (subcarry 0, (xor %a, %b))
// (sext (setcc %a, %b, setne)) -> (sube subfc.reg, subfc.reg, subfc.CA)
// {subfcz.reg, subfcz.CA} = (subcarry 0, %a)
// (sext (setcc %a, 0, setne)) -> (sube subfcz.reg, subfcz.reg, subfcz.CA)
SDValue Xor = IsRHSZero ? LHS :
SDValue(CurDAG->getMachineNode(PPC::XOR8, dl, MVT::i64, LHS, RHS), 0);
SDValue SC =
SDValue(CurDAG->getMachineNode(PPC::SUBFIC8, dl, MVT::i64, MVT::Glue,
Xor, S->getI32Imm(0, dl)), 0);
return SDValue(CurDAG->getMachineNode(PPC::SUBFE8, dl, MVT::i64, SC,
SC, SC.getValue(1)), 0);
}
case ISD::SETGE: {
// {subc.reg, subc.CA} = (subcarry %a, %b)
// (zext (setcc %a, %b, setge)) ->
// (- (adde (lshr %b, 63), (ashr %a, 63), subc.CA))
// (zext (setcc %a, 0, setge)) -> (~ (ashr %a, 63))
if (IsRHSZero)
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::GESExt);
std::swap(LHS, RHS);
ConstantSDNode *RHSConst = dyn_cast<ConstantSDNode>(RHS);
IsRHSZero = RHSConst && RHSConst->isNullValue();
LLVM_FALLTHROUGH;
}
case ISD::SETLE: {
// {subc.reg, subc.CA} = (subcarry %b, %a)
// (zext (setcc %a, %b, setge)) ->
// (- (adde (lshr %a, 63), (ashr %b, 63), subc.CA))
// (zext (setcc %a, 0, setge)) -> (ashr (or %a, (add %a, -1)), 63)
if (IsRHSZero)
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::LESExt);
SDValue ShiftR =
SDValue(CurDAG->getMachineNode(PPC::SRADI, dl, MVT::i64, RHS,
S->getI64Imm(63, dl)), 0);
SDValue ShiftL =
SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64, LHS,
S->getI64Imm(1, dl),
S->getI64Imm(63, dl)), 0);
SDValue SubtractCarry =
SDValue(CurDAG->getMachineNode(PPC::SUBFC8, dl, MVT::i64, MVT::Glue,
LHS, RHS), 1);
SDValue Adde =
SDValue(CurDAG->getMachineNode(PPC::ADDE8, dl, MVT::i64, MVT::Glue,
ShiftR, ShiftL, SubtractCarry), 0);
return SDValue(CurDAG->getMachineNode(PPC::NEG8, dl, MVT::i64, Adde), 0);
}
case ISD::SETGT: {
// {subc.reg, subc.CA} = (subcarry %b, %a)
// (zext (setcc %a, %b, setgt)) ->
// -(xor (adde (lshr %a, 63), (ashr %b, 63), subc.CA), 1)
// (zext (setcc %a, 0, setgt)) -> (ashr (nor (add %a, -1), %a), 63)
if (IsRHSNegOne)
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::GESExt);
if (IsRHSZero) {
SDValue Add =
SDValue(CurDAG->getMachineNode(PPC::ADDI8, dl, MVT::i64, LHS,
S->getI64Imm(-1, dl)), 0);
SDValue Nor =
SDValue(CurDAG->getMachineNode(PPC::NOR8, dl, MVT::i64, Add, LHS), 0);
return SDValue(CurDAG->getMachineNode(PPC::SRADI, dl, MVT::i64, Nor,
S->getI64Imm(63, dl)), 0);
}
std::swap(LHS, RHS);
ConstantSDNode *RHSConst = dyn_cast<ConstantSDNode>(RHS);
IsRHSZero = RHSConst && RHSConst->isNullValue();
IsRHSOne = RHSConst && RHSConst->getSExtValue() == 1;
LLVM_FALLTHROUGH;
}
case ISD::SETLT: {
// {subc.reg, subc.CA} = (subcarry %a, %b)
// (zext (setcc %a, %b, setlt)) ->
// -(xor (adde (lshr %b, 63), (ashr %a, 63), subc.CA), 1)
// (zext (setcc %a, 0, setlt)) -> (ashr %a, 63)
if (IsRHSOne)
return getCompoundZeroComparisonInGPR(LHS, dl, ZeroCompare::LESExt);
if (IsRHSZero) {
return SDValue(CurDAG->getMachineNode(PPC::SRADI, dl, MVT::i64, LHS,
S->getI64Imm(63, dl)), 0);
}
SDValue SRADINode =
SDValue(CurDAG->getMachineNode(PPC::SRADI, dl, MVT::i64,
LHS, S->getI64Imm(63, dl)), 0);
SDValue SRDINode =
SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64,
RHS, S->getI64Imm(1, dl),
S->getI64Imm(63, dl)), 0);
SDValue SUBFC8Carry =
SDValue(CurDAG->getMachineNode(PPC::SUBFC8, dl, MVT::i64, MVT::Glue,
RHS, LHS), 1);
SDValue ADDE8Node =
SDValue(CurDAG->getMachineNode(PPC::ADDE8, dl, MVT::i64,
SRDINode, SRADINode, SUBFC8Carry), 0);
SDValue XORI8Node =
SDValue(CurDAG->getMachineNode(PPC::XORI8, dl, MVT::i64,
ADDE8Node, S->getI64Imm(1, dl)), 0);
return SDValue(CurDAG->getMachineNode(PPC::NEG8, dl, MVT::i64,
XORI8Node), 0);
}
case ISD::SETUGE:
// {subc.reg, subc.CA} = (subcarry %a, %b)
// (sext (setcc %a, %b, setuge)) -> ~(sube %b, %b, subc.CA)
std::swap(LHS, RHS);
LLVM_FALLTHROUGH;
case ISD::SETULE: {
// {subc.reg, subc.CA} = (subcarry %b, %a)
// (sext (setcc %a, %b, setule)) -> ~(sube %a, %a, subc.CA)
SDValue SubtractCarry =
SDValue(CurDAG->getMachineNode(PPC::SUBFC8, dl, MVT::i64, MVT::Glue,
LHS, RHS), 1);
SDValue ExtSub =
SDValue(CurDAG->getMachineNode(PPC::SUBFE8, dl, MVT::i64, MVT::Glue, LHS,
LHS, SubtractCarry), 0);
return SDValue(CurDAG->getMachineNode(PPC::NOR8, dl, MVT::i64,
ExtSub, ExtSub), 0);
}
case ISD::SETUGT:
// {subc.reg, subc.CA} = (subcarry %b, %a)
// (sext (setcc %a, %b, setugt)) -> (sube %b, %b, subc.CA)
std::swap(LHS, RHS);
LLVM_FALLTHROUGH;
case ISD::SETULT: {
// {subc.reg, subc.CA} = (subcarry %a, %b)
// (sext (setcc %a, %b, setult)) -> (sube %a, %a, subc.CA)
SDValue SubCarry =
SDValue(CurDAG->getMachineNode(PPC::SUBFC8, dl, MVT::i64, MVT::Glue,
RHS, LHS), 1);
return SDValue(CurDAG->getMachineNode(PPC::SUBFE8, dl, MVT::i64,
LHS, LHS, SubCarry), 0);
}
}
}
/// Do all uses of this SDValue need the result in a GPR?
/// This is meant to be used on values that have type i1 since
/// it is somewhat meaningless to ask if values of other types
/// should be kept in GPR's.
static bool allUsesExtend(SDValue Compare, SelectionDAG *CurDAG) {
assert(Compare.getOpcode() == ISD::SETCC &&
"An ISD::SETCC node required here.");
// For values that have a single use, the caller should obviously already have
// checked if that use is an extending use. We check the other uses here.
if (Compare.hasOneUse())
return true;
// We want the value in a GPR if it is being extended, used for a select, or
// used in logical operations.
for (auto CompareUse : Compare.getNode()->uses())
if (CompareUse->getOpcode() != ISD::SIGN_EXTEND &&
CompareUse->getOpcode() != ISD::ZERO_EXTEND &&
CompareUse->getOpcode() != ISD::SELECT &&
!isLogicOp(CompareUse->getOpcode())) {
OmittedForNonExtendUses++;
return false;
}
return true;
}
/// Returns an equivalent of a SETCC node but with the result the same width as
/// the inputs. This can also be used for SELECT_CC if either the true or false
/// values is a power of two while the other is zero.
SDValue IntegerCompareEliminator::getSETCCInGPR(SDValue Compare,
SetccInGPROpts ConvOpts) {
assert((Compare.getOpcode() == ISD::SETCC ||
Compare.getOpcode() == ISD::SELECT_CC) &&
"An ISD::SETCC node required here.");
// Don't convert this comparison to a GPR sequence because there are uses
// of the i1 result (i.e. uses that require the result in the CR).
if ((Compare.getOpcode() == ISD::SETCC) && !allUsesExtend(Compare, CurDAG))
return SDValue();
SDValue LHS = Compare.getOperand(0);
SDValue RHS = Compare.getOperand(1);
// The condition code is operand 2 for SETCC and operand 4 for SELECT_CC.
int CCOpNum = Compare.getOpcode() == ISD::SELECT_CC ? 4 : 2;
ISD::CondCode CC =
cast<CondCodeSDNode>(Compare.getOperand(CCOpNum))->get();
EVT InputVT = LHS.getValueType();
if (InputVT != MVT::i32 && InputVT != MVT::i64)
return SDValue();
if (ConvOpts == SetccInGPROpts::ZExtInvert ||
ConvOpts == SetccInGPROpts::SExtInvert)
CC = ISD::getSetCCInverse(CC, true);
bool Inputs32Bit = InputVT == MVT::i32;
SDLoc dl(Compare);
ConstantSDNode *RHSConst = dyn_cast<ConstantSDNode>(RHS);
int64_t RHSValue = RHSConst ? RHSConst->getSExtValue() : INT64_MAX;
bool IsSext = ConvOpts == SetccInGPROpts::SExtOrig ||
ConvOpts == SetccInGPROpts::SExtInvert;
if (IsSext && Inputs32Bit)
return get32BitSExtCompare(LHS, RHS, CC, RHSValue, dl);
else if (Inputs32Bit)
return get32BitZExtCompare(LHS, RHS, CC, RHSValue, dl);
else if (IsSext)
return get64BitSExtCompare(LHS, RHS, CC, RHSValue, dl);
return get64BitZExtCompare(LHS, RHS, CC, RHSValue, dl);
}
} // end anonymous namespace
bool PPCDAGToDAGISel::tryIntCompareInGPR(SDNode *N) {
if (N->getValueType(0) != MVT::i32 &&
N->getValueType(0) != MVT::i64)
return false;
// This optimization will emit code that assumes 64-bit registers
// so we don't want to run it in 32-bit mode. Also don't run it
// on functions that are not to be optimized.
if (TM.getOptLevel() == CodeGenOpt::None || !TM.isPPC64())
return false;
switch (N->getOpcode()) {
default: break;
case ISD::ZERO_EXTEND:
case ISD::SIGN_EXTEND:
case ISD::AND:
case ISD::OR:
case ISD::XOR: {
IntegerCompareEliminator ICmpElim(CurDAG, this);
if (SDNode *New = ICmpElim.Select(N)) {
ReplaceNode(N, New);
return true;
}
}
}
return false;
}
bool PPCDAGToDAGISel::tryBitPermutation(SDNode *N) {
if (N->getValueType(0) != MVT::i32 &&
N->getValueType(0) != MVT::i64)
return false;
if (!UseBitPermRewriter)
return false;
switch (N->getOpcode()) {
default: break;
case ISD::ROTL:
case ISD::SHL:
case ISD::SRL:
case ISD::AND:
case ISD::OR: {
BitPermutationSelector BPS(CurDAG);
if (SDNode *New = BPS.Select(N)) {
ReplaceNode(N, New);
return true;
}
return false;
}
}
return false;
}
/// SelectCC - Select a comparison of the specified values with the specified
/// condition code, returning the CR# of the expression.
SDValue PPCDAGToDAGISel::SelectCC(SDValue LHS, SDValue RHS, ISD::CondCode CC,
const SDLoc &dl) {
// Always select the LHS.
unsigned Opc;
if (LHS.getValueType() == MVT::i32) {
unsigned Imm;
if (CC == ISD::SETEQ || CC == ISD::SETNE) {
if (isInt32Immediate(RHS, Imm)) {
// SETEQ/SETNE comparison with 16-bit immediate, fold it.
if (isUInt<16>(Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPLWI, dl, MVT::i32, LHS,
getI32Imm(Imm & 0xFFFF, dl)),
0);
// If this is a 16-bit signed immediate, fold it.
if (isInt<16>((int)Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPWI, dl, MVT::i32, LHS,
getI32Imm(Imm & 0xFFFF, dl)),
0);
// For non-equality comparisons, the default code would materialize the
// constant, then compare against it, like this:
// lis r2, 4660
// ori r2, r2, 22136
// cmpw cr0, r3, r2
// Since we are just comparing for equality, we can emit this instead:
// xoris r0,r3,0x1234
// cmplwi cr0,r0,0x5678
// beq cr0,L6
SDValue Xor(CurDAG->getMachineNode(PPC::XORIS, dl, MVT::i32, LHS,
getI32Imm(Imm >> 16, dl)), 0);
return SDValue(CurDAG->getMachineNode(PPC::CMPLWI, dl, MVT::i32, Xor,
getI32Imm(Imm & 0xFFFF, dl)), 0);
}
Opc = PPC::CMPLW;
} else if (ISD::isUnsignedIntSetCC(CC)) {
if (isInt32Immediate(RHS, Imm) && isUInt<16>(Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPLWI, dl, MVT::i32, LHS,
getI32Imm(Imm & 0xFFFF, dl)), 0);
Opc = PPC::CMPLW;
} else {
int16_t SImm;
if (isIntS16Immediate(RHS, SImm))
return SDValue(CurDAG->getMachineNode(PPC::CMPWI, dl, MVT::i32, LHS,
getI32Imm((int)SImm & 0xFFFF,
dl)),
0);
Opc = PPC::CMPW;
}
} else if (LHS.getValueType() == MVT::i64) {
uint64_t Imm;
if (CC == ISD::SETEQ || CC == ISD::SETNE) {
if (isInt64Immediate(RHS.getNode(), Imm)) {
// SETEQ/SETNE comparison with 16-bit immediate, fold it.
if (isUInt<16>(Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPLDI, dl, MVT::i64, LHS,
getI32Imm(Imm & 0xFFFF, dl)),
0);
// If this is a 16-bit signed immediate, fold it.
if (isInt<16>(Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPDI, dl, MVT::i64, LHS,
getI32Imm(Imm & 0xFFFF, dl)),
0);
// For non-equality comparisons, the default code would materialize the
// constant, then compare against it, like this:
// lis r2, 4660
// ori r2, r2, 22136
// cmpd cr0, r3, r2
// Since we are just comparing for equality, we can emit this instead:
// xoris r0,r3,0x1234
// cmpldi cr0,r0,0x5678
// beq cr0,L6
if (isUInt<32>(Imm)) {
SDValue Xor(CurDAG->getMachineNode(PPC::XORIS8, dl, MVT::i64, LHS,
getI64Imm(Imm >> 16, dl)), 0);
return SDValue(CurDAG->getMachineNode(PPC::CMPLDI, dl, MVT::i64, Xor,
getI64Imm(Imm & 0xFFFF, dl)),
0);
}
}
Opc = PPC::CMPLD;
} else if (ISD::isUnsignedIntSetCC(CC)) {
if (isInt64Immediate(RHS.getNode(), Imm) && isUInt<16>(Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPLDI, dl, MVT::i64, LHS,
getI64Imm(Imm & 0xFFFF, dl)), 0);
Opc = PPC::CMPLD;
} else {
int16_t SImm;
if (isIntS16Immediate(RHS, SImm))
return SDValue(CurDAG->getMachineNode(PPC::CMPDI, dl, MVT::i64, LHS,
getI64Imm(SImm & 0xFFFF, dl)),
0);
Opc = PPC::CMPD;
}
} else if (LHS.getValueType() == MVT::f32) {
if (PPCSubTarget->hasSPE()) {
switch (CC) {
default:
case ISD::SETEQ:
case ISD::SETNE:
Opc = PPC::EFSCMPEQ;
break;
case ISD::SETLT:
case ISD::SETGE:
case ISD::SETOLT:
case ISD::SETOGE:
case ISD::SETULT:
case ISD::SETUGE:
Opc = PPC::EFSCMPLT;
break;
case ISD::SETGT:
case ISD::SETLE:
case ISD::SETOGT:
case ISD::SETOLE:
case ISD::SETUGT:
case ISD::SETULE:
Opc = PPC::EFSCMPGT;
break;
}
} else
Opc = PPC::FCMPUS;
} else if (LHS.getValueType() == MVT::f64) {
if (PPCSubTarget->hasSPE()) {
switch (CC) {
default:
case ISD::SETEQ:
case ISD::SETNE:
Opc = PPC::EFDCMPEQ;
break;
case ISD::SETLT:
case ISD::SETGE:
case ISD::SETOLT:
case ISD::SETOGE:
case ISD::SETULT:
case ISD::SETUGE:
Opc = PPC::EFDCMPLT;
break;
case ISD::SETGT:
case ISD::SETLE:
case ISD::SETOGT:
case ISD::SETOLE:
case ISD::SETUGT:
case ISD::SETULE:
Opc = PPC::EFDCMPGT;
break;
}
} else
Opc = PPCSubTarget->hasVSX() ? PPC::XSCMPUDP : PPC::FCMPUD;
} else {
assert(LHS.getValueType() == MVT::f128 && "Unknown vt!");
assert(PPCSubTarget->hasVSX() && "__float128 requires VSX");
Opc = PPC::XSCMPUQP;
}
return SDValue(CurDAG->getMachineNode(Opc, dl, MVT::i32, LHS, RHS), 0);
}
static PPC::Predicate getPredicateForSetCC(ISD::CondCode CC) {
switch (CC) {
case ISD::SETUEQ:
case ISD::SETONE:
case ISD::SETOLE:
case ISD::SETOGE:
llvm_unreachable("Should be lowered by legalize!");
default: llvm_unreachable("Unknown condition!");
case ISD::SETOEQ:
case ISD::SETEQ: return PPC::PRED_EQ;
case ISD::SETUNE:
case ISD::SETNE: return PPC::PRED_NE;
case ISD::SETOLT:
case ISD::SETLT: return PPC::PRED_LT;
case ISD::SETULE:
case ISD::SETLE: return PPC::PRED_LE;
case ISD::SETOGT:
case ISD::SETGT: return PPC::PRED_GT;
case ISD::SETUGE:
case ISD::SETGE: return PPC::PRED_GE;
case ISD::SETO: return PPC::PRED_NU;
case ISD::SETUO: return PPC::PRED_UN;
// These two are invalid for floating point. Assume we have int.
case ISD::SETULT: return PPC::PRED_LT;
case ISD::SETUGT: return PPC::PRED_GT;
}
}
/// getCRIdxForSetCC - Return the index of the condition register field
/// associated with the SetCC condition, and whether or not the field is
/// treated as inverted. That is, lt = 0; ge = 0 inverted.
static unsigned getCRIdxForSetCC(ISD::CondCode CC, bool &Invert) {
Invert = false;
switch (CC) {
default: llvm_unreachable("Unknown condition!");
case ISD::SETOLT:
case ISD::SETLT: return 0; // Bit #0 = SETOLT
case ISD::SETOGT:
case ISD::SETGT: return 1; // Bit #1 = SETOGT
case ISD::SETOEQ:
case ISD::SETEQ: return 2; // Bit #2 = SETOEQ
case ISD::SETUO: return 3; // Bit #3 = SETUO
case ISD::SETUGE:
case ISD::SETGE: Invert = true; return 0; // !Bit #0 = SETUGE
case ISD::SETULE:
case ISD::SETLE: Invert = true; return 1; // !Bit #1 = SETULE
case ISD::SETUNE:
case ISD::SETNE: Invert = true; return 2; // !Bit #2 = SETUNE
case ISD::SETO: Invert = true; return 3; // !Bit #3 = SETO
case ISD::SETUEQ:
case ISD::SETOGE:
case ISD::SETOLE:
case ISD::SETONE:
llvm_unreachable("Invalid branch code: should be expanded by legalize");
// These are invalid for floating point. Assume integer.
case ISD::SETULT: return 0;
case ISD::SETUGT: return 1;
}
}
// getVCmpInst: return the vector compare instruction for the specified
// vector type and condition code. Since this is for altivec specific code,
// only support the altivec types (v16i8, v8i16, v4i32, v2i64, and v4f32).
static unsigned int getVCmpInst(MVT VecVT, ISD::CondCode CC,
bool HasVSX, bool &Swap, bool &Negate) {
Swap = false;
Negate = false;
if (VecVT.isFloatingPoint()) {
/* Handle some cases by swapping input operands. */
switch (CC) {
case ISD::SETLE: CC = ISD::SETGE; Swap = true; break;
case ISD::SETLT: CC = ISD::SETGT; Swap = true; break;
case ISD::SETOLE: CC = ISD::SETOGE; Swap = true; break;
case ISD::SETOLT: CC = ISD::SETOGT; Swap = true; break;
case ISD::SETUGE: CC = ISD::SETULE; Swap = true; break;
case ISD::SETUGT: CC = ISD::SETULT; Swap = true; break;
default: break;
}
/* Handle some cases by negating the result. */
switch (CC) {
case ISD::SETNE: CC = ISD::SETEQ; Negate = true; break;
case ISD::SETUNE: CC = ISD::SETOEQ; Negate = true; break;
case ISD::SETULE: CC = ISD::SETOGT; Negate = true; break;
case ISD::SETULT: CC = ISD::SETOGE; Negate = true; break;
default: break;
}
/* We have instructions implementing the remaining cases. */
switch (CC) {
case ISD::SETEQ:
case ISD::SETOEQ:
if (VecVT == MVT::v4f32)
return HasVSX ? PPC::XVCMPEQSP : PPC::VCMPEQFP;
else if (VecVT == MVT::v2f64)
return PPC::XVCMPEQDP;
break;
case ISD::SETGT:
case ISD::SETOGT:
if (VecVT == MVT::v4f32)
return HasVSX ? PPC::XVCMPGTSP : PPC::VCMPGTFP;
else if (VecVT == MVT::v2f64)
return PPC::XVCMPGTDP;
break;
case ISD::SETGE:
case ISD::SETOGE:
if (VecVT == MVT::v4f32)
return HasVSX ? PPC::XVCMPGESP : PPC::VCMPGEFP;
else if (VecVT == MVT::v2f64)
return PPC::XVCMPGEDP;
break;
default:
break;
}
llvm_unreachable("Invalid floating-point vector compare condition");
} else {
/* Handle some cases by swapping input operands. */
switch (CC) {
case ISD::SETGE: CC = ISD::SETLE; Swap = true; break;
case ISD::SETLT: CC = ISD::SETGT; Swap = true; break;
case ISD::SETUGE: CC = ISD::SETULE; Swap = true; break;
case ISD::SETULT: CC = ISD::SETUGT; Swap = true; break;
default: break;
}
/* Handle some cases by negating the result. */
switch (CC) {
case ISD::SETNE: CC = ISD::SETEQ; Negate = true; break;
case ISD::SETUNE: CC = ISD::SETUEQ; Negate = true; break;
case ISD::SETLE: CC = ISD::SETGT; Negate = true; break;
case ISD::SETULE: CC = ISD::SETUGT; Negate = true; break;
default: break;
}
/* We have instructions implementing the remaining cases. */
switch (CC) {
case ISD::SETEQ:
case ISD::SETUEQ:
if (VecVT == MVT::v16i8)
return PPC::VCMPEQUB;
else if (VecVT == MVT::v8i16)
return PPC::VCMPEQUH;
else if (VecVT == MVT::v4i32)
return PPC::VCMPEQUW;
else if (VecVT == MVT::v2i64)
return PPC::VCMPEQUD;
break;
case ISD::SETGT:
if (VecVT == MVT::v16i8)
return PPC::VCMPGTSB;
else if (VecVT == MVT::v8i16)
return PPC::VCMPGTSH;
else if (VecVT == MVT::v4i32)
return PPC::VCMPGTSW;
else if (VecVT == MVT::v2i64)
return PPC::VCMPGTSD;
break;
case ISD::SETUGT:
if (VecVT == MVT::v16i8)
return PPC::VCMPGTUB;
else if (VecVT == MVT::v8i16)
return PPC::VCMPGTUH;
else if (VecVT == MVT::v4i32)
return PPC::VCMPGTUW;
else if (VecVT == MVT::v2i64)
return PPC::VCMPGTUD;
break;
default:
break;
}
llvm_unreachable("Invalid integer vector compare condition");
}
}
bool PPCDAGToDAGISel::trySETCC(SDNode *N) {
SDLoc dl(N);
unsigned Imm;
ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get();
EVT PtrVT =
CurDAG->getTargetLoweringInfo().getPointerTy(CurDAG->getDataLayout());
bool isPPC64 = (PtrVT == MVT::i64);
if (!PPCSubTarget->useCRBits() &&
isInt32Immediate(N->getOperand(1), Imm)) {
// We can codegen setcc op, imm very efficiently compared to a brcond.
// Check for those cases here.
// setcc op, 0
if (Imm == 0) {
SDValue Op = N->getOperand(0);
switch (CC) {
default: break;
case ISD::SETEQ: {
Op = SDValue(CurDAG->getMachineNode(PPC::CNTLZW, dl, MVT::i32, Op), 0);
SDValue Ops[] = { Op, getI32Imm(27, dl), getI32Imm(5, dl),
getI32Imm(31, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return true;
}
case ISD::SETNE: {
if (isPPC64) break;
SDValue AD =
SDValue(CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
Op, getI32Imm(~0U, dl)), 0);
CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, AD, Op, AD.getValue(1));
return true;
}
case ISD::SETLT: {
SDValue Ops[] = { Op, getI32Imm(1, dl), getI32Imm(31, dl),
getI32Imm(31, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return true;
}
case ISD::SETGT: {
SDValue T =
SDValue(CurDAG->getMachineNode(PPC::NEG, dl, MVT::i32, Op), 0);
T = SDValue(CurDAG->getMachineNode(PPC::ANDC, dl, MVT::i32, T, Op), 0);
SDValue Ops[] = { T, getI32Imm(1, dl), getI32Imm(31, dl),
getI32Imm(31, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return true;
}
}
} else if (Imm == ~0U) { // setcc op, -1
SDValue Op = N->getOperand(0);
switch (CC) {
default: break;
case ISD::SETEQ:
if (isPPC64) break;
Op = SDValue(CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
Op, getI32Imm(1, dl)), 0);
CurDAG->SelectNodeTo(N, PPC::ADDZE, MVT::i32,
SDValue(CurDAG->getMachineNode(PPC::LI, dl,
MVT::i32,
getI32Imm(0, dl)),
0), Op.getValue(1));
return true;
case ISD::SETNE: {
if (isPPC64) break;
Op = SDValue(CurDAG->getMachineNode(PPC::NOR, dl, MVT::i32, Op, Op), 0);
SDNode *AD = CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
Op, getI32Imm(~0U, dl));
CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, SDValue(AD, 0), Op,
SDValue(AD, 1));
return true;
}
case ISD::SETLT: {
SDValue AD = SDValue(CurDAG->getMachineNode(PPC::ADDI, dl, MVT::i32, Op,
getI32Imm(1, dl)), 0);
SDValue AN = SDValue(CurDAG->getMachineNode(PPC::AND, dl, MVT::i32, AD,
Op), 0);
SDValue Ops[] = { AN, getI32Imm(1, dl), getI32Imm(31, dl),
getI32Imm(31, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return true;
}
case ISD::SETGT: {
SDValue Ops[] = { Op, getI32Imm(1, dl), getI32Imm(31, dl),
getI32Imm(31, dl) };
Op = SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops), 0);
CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Op, getI32Imm(1, dl));
return true;
}
}
}
}
SDValue LHS = N->getOperand(0);
SDValue RHS = N->getOperand(1);
// Altivec Vector compare instructions do not set any CR register by default and
// vector compare operations return the same type as the operands.
if (LHS.getValueType().isVector()) {
if (PPCSubTarget->hasQPX() || PPCSubTarget->hasSPE())
return false;
EVT VecVT = LHS.getValueType();
bool Swap, Negate;
unsigned int VCmpInst = getVCmpInst(VecVT.getSimpleVT(), CC,
PPCSubTarget->hasVSX(), Swap, Negate);
if (Swap)
std::swap(LHS, RHS);
EVT ResVT = VecVT.changeVectorElementTypeToInteger();
if (Negate) {
SDValue VCmp(CurDAG->getMachineNode(VCmpInst, dl, ResVT, LHS, RHS), 0);
CurDAG->SelectNodeTo(N, PPCSubTarget->hasVSX() ? PPC::XXLNOR : PPC::VNOR,
ResVT, VCmp, VCmp);
return true;
}
CurDAG->SelectNodeTo(N, VCmpInst, ResVT, LHS, RHS);
return true;
}
if (PPCSubTarget->useCRBits())
return false;
bool Inv;
unsigned Idx = getCRIdxForSetCC(CC, Inv);
SDValue CCReg = SelectCC(LHS, RHS, CC, dl);
SDValue IntCR;
// SPE e*cmp* instructions only set the 'gt' bit, so hard-code that
// The correct compare instruction is already set by SelectCC()
if (PPCSubTarget->hasSPE() && LHS.getValueType().isFloatingPoint()) {
Idx = 1;
}
// Force the ccreg into CR7.
SDValue CR7Reg = CurDAG->getRegister(PPC::CR7, MVT::i32);
SDValue InFlag(nullptr, 0); // Null incoming flag value.
CCReg = CurDAG->getCopyToReg(CurDAG->getEntryNode(), dl, CR7Reg, CCReg,
InFlag).getValue(1);
IntCR = SDValue(CurDAG->getMachineNode(PPC::MFOCRF, dl, MVT::i32, CR7Reg,
CCReg), 0);
SDValue Ops[] = { IntCR, getI32Imm((32 - (3 - Idx)) & 31, dl),
getI32Imm(31, dl), getI32Imm(31, dl) };
if (!Inv) {
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return true;
}
// Get the specified bit.
SDValue Tmp =
SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops), 0);
CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Tmp, getI32Imm(1, dl));
return true;
}
/// Does this node represent a load/store node whose address can be represented
/// with a register plus an immediate that's a multiple of \p Val:
bool PPCDAGToDAGISel::isOffsetMultipleOf(SDNode *N, unsigned Val) const {
LoadSDNode *LDN = dyn_cast<LoadSDNode>(N);
StoreSDNode *STN = dyn_cast<StoreSDNode>(N);
SDValue AddrOp;
if (LDN)
AddrOp = LDN->getOperand(1);
else if (STN)
AddrOp = STN->getOperand(2);
// If the address points a frame object or a frame object with an offset,
// we need to check the object alignment.
short Imm = 0;
if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(
AddrOp.getOpcode() == ISD::ADD ? AddrOp.getOperand(0) :
AddrOp)) {
// If op0 is a frame index that is under aligned, we can't do it either,
// because it is translated to r31 or r1 + slot + offset. We won't know the
// slot number until the stack frame is finalized.
const MachineFrameInfo &MFI = CurDAG->getMachineFunction().getFrameInfo();
unsigned SlotAlign = MFI.getObjectAlignment(FI->getIndex());
if ((SlotAlign % Val) != 0)
return false;
// If we have an offset, we need further check on the offset.
if (AddrOp.getOpcode() != ISD::ADD)
return true;
}
if (AddrOp.getOpcode() == ISD::ADD)
return isIntS16Immediate(AddrOp.getOperand(1), Imm) && !(Imm % Val);
// If the address comes from the outside, the offset will be zero.
return AddrOp.getOpcode() == ISD::CopyFromReg;
}
void PPCDAGToDAGISel::transferMemOperands(SDNode *N, SDNode *Result) {
// Transfer memoperands.
MachineMemOperand *MemOp = cast<MemSDNode>(N)->getMemOperand();
CurDAG->setNodeMemRefs(cast<MachineSDNode>(Result), {MemOp});
}
static bool mayUseP9Setb(SDNode *N, const ISD::CondCode &CC, SelectionDAG *DAG,
bool &NeedSwapOps, bool &IsUnCmp) {
assert(N->getOpcode() == ISD::SELECT_CC && "Expecting a SELECT_CC here.");
SDValue LHS = N->getOperand(0);
SDValue RHS = N->getOperand(1);
SDValue TrueRes = N->getOperand(2);
SDValue FalseRes = N->getOperand(3);
ConstantSDNode *TrueConst = dyn_cast<ConstantSDNode>(TrueRes);
if (!TrueConst)
return false;
assert((N->getSimpleValueType(0) == MVT::i64 ||
N->getSimpleValueType(0) == MVT::i32) &&
"Expecting either i64 or i32 here.");
// We are looking for any of:
// (select_cc lhs, rhs, 1, (sext (setcc [lr]hs, [lr]hs, cc2)), cc1)
// (select_cc lhs, rhs, -1, (zext (setcc [lr]hs, [lr]hs, cc2)), cc1)
// (select_cc lhs, rhs, 0, (select_cc [lr]hs, [lr]hs, 1, -1, cc2), seteq)
// (select_cc lhs, rhs, 0, (select_cc [lr]hs, [lr]hs, -1, 1, cc2), seteq)
int64_t TrueResVal = TrueConst->getSExtValue();
if ((TrueResVal < -1 || TrueResVal > 1) ||
(TrueResVal == -1 && FalseRes.getOpcode() != ISD::ZERO_EXTEND) ||
(TrueResVal == 1 && FalseRes.getOpcode() != ISD::SIGN_EXTEND) ||
(TrueResVal == 0 &&
(FalseRes.getOpcode() != ISD::SELECT_CC || CC != ISD::SETEQ)))
return false;
bool InnerIsSel = FalseRes.getOpcode() == ISD::SELECT_CC;
SDValue SetOrSelCC = InnerIsSel ? FalseRes : FalseRes.getOperand(0);
if (SetOrSelCC.getOpcode() != ISD::SETCC &&
SetOrSelCC.getOpcode() != ISD::SELECT_CC)
return false;
// Without this setb optimization, the outer SELECT_CC will be manually
// selected to SELECT_CC_I4/SELECT_CC_I8 Pseudo, then expand-isel-pseudos pass
// transforms pseudo instruction to isel instruction. When there are more than
// one use for result like zext/sext, with current optimization we only see
// isel is replaced by setb but can't see any significant gain. Since
// setb has longer latency than original isel, we should avoid this. Another
// point is that setb requires comparison always kept, it can break the
// opportunity to get the comparison away if we have in future.
if (!SetOrSelCC.hasOneUse() || (!InnerIsSel && !FalseRes.hasOneUse()))
return false;
SDValue InnerLHS = SetOrSelCC.getOperand(0);
SDValue InnerRHS = SetOrSelCC.getOperand(1);
ISD::CondCode InnerCC =
cast<CondCodeSDNode>(SetOrSelCC.getOperand(InnerIsSel ? 4 : 2))->get();
// If the inner comparison is a select_cc, make sure the true/false values are
// 1/-1 and canonicalize it if needed.
if (InnerIsSel) {
ConstantSDNode *SelCCTrueConst =
dyn_cast<ConstantSDNode>(SetOrSelCC.getOperand(2));
ConstantSDNode *SelCCFalseConst =
dyn_cast<ConstantSDNode>(SetOrSelCC.getOperand(3));
if (!SelCCTrueConst || !SelCCFalseConst)
return false;
int64_t SelCCTVal = SelCCTrueConst->getSExtValue();
int64_t SelCCFVal = SelCCFalseConst->getSExtValue();
// The values must be -1/1 (requiring a swap) or 1/-1.
if (SelCCTVal == -1 && SelCCFVal == 1) {
std::swap(InnerLHS, InnerRHS);
} else if (SelCCTVal != 1 || SelCCFVal != -1)
return false;
}
// Canonicalize unsigned case
if (InnerCC == ISD::SETULT || InnerCC == ISD::SETUGT) {
IsUnCmp = true;
InnerCC = (InnerCC == ISD::SETULT) ? ISD::SETLT : ISD::SETGT;
}
bool InnerSwapped = false;
if (LHS == InnerRHS && RHS == InnerLHS)
InnerSwapped = true;
else if (LHS != InnerLHS || RHS != InnerRHS)
return false;
switch (CC) {
// (select_cc lhs, rhs, 0, \
// (select_cc [lr]hs, [lr]hs, 1, -1, setlt/setgt), seteq)
case ISD::SETEQ:
if (!InnerIsSel)
return false;
if (InnerCC != ISD::SETLT && InnerCC != ISD::SETGT)
return false;
NeedSwapOps = (InnerCC == ISD::SETGT) ? InnerSwapped : !InnerSwapped;
break;
// (select_cc lhs, rhs, -1, (zext (setcc [lr]hs, [lr]hs, setne)), setu?lt)
// (select_cc lhs, rhs, -1, (zext (setcc lhs, rhs, setgt)), setu?lt)
// (select_cc lhs, rhs, -1, (zext (setcc rhs, lhs, setlt)), setu?lt)
// (select_cc lhs, rhs, 1, (sext (setcc [lr]hs, [lr]hs, setne)), setu?lt)
// (select_cc lhs, rhs, 1, (sext (setcc lhs, rhs, setgt)), setu?lt)
// (select_cc lhs, rhs, 1, (sext (setcc rhs, lhs, setlt)), setu?lt)
case ISD::SETULT:
if (!IsUnCmp && InnerCC != ISD::SETNE)
return false;
IsUnCmp = true;
LLVM_FALLTHROUGH;
case ISD::SETLT:
if (InnerCC == ISD::SETNE || (InnerCC == ISD::SETGT && !InnerSwapped) ||
(InnerCC == ISD::SETLT && InnerSwapped))
NeedSwapOps = (TrueResVal == 1);
else
return false;
break;
// (select_cc lhs, rhs, 1, (sext (setcc [lr]hs, [lr]hs, setne)), setu?gt)
// (select_cc lhs, rhs, 1, (sext (setcc lhs, rhs, setlt)), setu?gt)
// (select_cc lhs, rhs, 1, (sext (setcc rhs, lhs, setgt)), setu?gt)
// (select_cc lhs, rhs, -1, (zext (setcc [lr]hs, [lr]hs, setne)), setu?gt)
// (select_cc lhs, rhs, -1, (zext (setcc lhs, rhs, setlt)), setu?gt)
// (select_cc lhs, rhs, -1, (zext (setcc rhs, lhs, setgt)), setu?gt)
case ISD::SETUGT:
if (!IsUnCmp && InnerCC != ISD::SETNE)
return false;
IsUnCmp = true;
LLVM_FALLTHROUGH;
case ISD::SETGT:
if (InnerCC == ISD::SETNE || (InnerCC == ISD::SETLT && !InnerSwapped) ||
(InnerCC == ISD::SETGT && InnerSwapped))
NeedSwapOps = (TrueResVal == -1);
else
return false;
break;
default:
return false;
}
LLVM_DEBUG(dbgs() << "Found a node that can be lowered to a SETB: ");
LLVM_DEBUG(N->dump());
return true;
}
// Select - Convert the specified operand from a target-independent to a
// target-specific node if it hasn't already been changed.
void PPCDAGToDAGISel::Select(SDNode *N) {
SDLoc dl(N);
if (N->isMachineOpcode()) {
N->setNodeId(-1);
return; // Already selected.
}
// In case any misguided DAG-level optimizations form an ADD with a
// TargetConstant operand, crash here instead of miscompiling (by selecting
// an r+r add instead of some kind of r+i add).
if (N->getOpcode() == ISD::ADD &&
N->getOperand(1).getOpcode() == ISD::TargetConstant)
llvm_unreachable("Invalid ADD with TargetConstant operand");
// Try matching complex bit permutations before doing anything else.
if (tryBitPermutation(N))
return;
// Try to emit integer compares as GPR-only sequences (i.e. no use of CR).
if (tryIntCompareInGPR(N))
return;
switch (N->getOpcode()) {
default: break;
case ISD::Constant:
if (N->getValueType(0) == MVT::i64) {
ReplaceNode(N, selectI64Imm(CurDAG, N));
return;
}
break;
case ISD::SETCC:
if (trySETCC(N))
return;
break;
// These nodes will be transformed into GETtlsADDR32 node, which
// later becomes BL_TLS __tls_get_addr(sym at tlsgd)@PLT
case PPCISD::ADDI_TLSLD_L_ADDR:
case PPCISD::ADDI_TLSGD_L_ADDR: {
const Module *Mod = MF->getFunction().getParent();
if (PPCLowering->getPointerTy(CurDAG->getDataLayout()) != MVT::i32 ||
!PPCSubTarget->isSecurePlt() || !PPCSubTarget->isTargetELF() ||
Mod->getPICLevel() == PICLevel::SmallPIC)
break;
// Attach global base pointer on GETtlsADDR32 node in order to
// generate secure plt code for TLS symbols.
getGlobalBaseReg();
} break;
case PPCISD::CALL: {
if (PPCLowering->getPointerTy(CurDAG->getDataLayout()) != MVT::i32 ||
!TM.isPositionIndependent() || !PPCSubTarget->isSecurePlt() ||
!PPCSubTarget->isTargetELF())
break;
SDValue Op = N->getOperand(1);
if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(Op)) {
if (GA->getTargetFlags() == PPCII::MO_PLT)
getGlobalBaseReg();
}
else if (ExternalSymbolSDNode *ES = dyn_cast<ExternalSymbolSDNode>(Op)) {
if (ES->getTargetFlags() == PPCII::MO_PLT)
getGlobalBaseReg();
}
}
break;
case PPCISD::GlobalBaseReg:
ReplaceNode(N, getGlobalBaseReg());
return;
case ISD::FrameIndex:
selectFrameIndex(N, N);
return;
case PPCISD::MFOCRF: {
SDValue InFlag = N->getOperand(1);
ReplaceNode(N, CurDAG->getMachineNode(PPC::MFOCRF, dl, MVT::i32,
N->getOperand(0), InFlag));
return;
}
case PPCISD::READ_TIME_BASE:
ReplaceNode(N, CurDAG->getMachineNode(PPC::ReadTB, dl, MVT::i32, MVT::i32,
MVT::Other, N->getOperand(0)));
return;
case PPCISD::SRA_ADDZE: {
SDValue N0 = N->getOperand(0);
SDValue ShiftAmt =
CurDAG->getTargetConstant(*cast<ConstantSDNode>(N->getOperand(1))->
getConstantIntValue(), dl,
N->getValueType(0));
if (N->getValueType(0) == MVT::i64) {
SDNode *Op =
CurDAG->getMachineNode(PPC::SRADI, dl, MVT::i64, MVT::Glue,
N0, ShiftAmt);
CurDAG->SelectNodeTo(N, PPC::ADDZE8, MVT::i64, SDValue(Op, 0),
SDValue(Op, 1));
return;
} else {
assert(N->getValueType(0) == MVT::i32 &&
"Expecting i64 or i32 in PPCISD::SRA_ADDZE");
SDNode *Op =
CurDAG->getMachineNode(PPC::SRAWI, dl, MVT::i32, MVT::Glue,
N0, ShiftAmt);
CurDAG->SelectNodeTo(N, PPC::ADDZE, MVT::i32, SDValue(Op, 0),
SDValue(Op, 1));
return;
}
}
case ISD::STORE: {
// Change TLS initial-exec D-form stores to X-form stores.
StoreSDNode *ST = cast<StoreSDNode>(N);
if (EnableTLSOpt && PPCSubTarget->isELFv2ABI() &&
ST->getAddressingMode() != ISD::PRE_INC)
if (tryTLSXFormStore(ST))
return;
break;
}
case ISD::LOAD: {
// Handle preincrement loads.
LoadSDNode *LD = cast<LoadSDNode>(N);
EVT LoadedVT = LD->getMemoryVT();
// Normal loads are handled by code generated from the .td file.
if (LD->getAddressingMode() != ISD::PRE_INC) {
// Change TLS initial-exec D-form loads to X-form loads.
if (EnableTLSOpt && PPCSubTarget->isELFv2ABI())
if (tryTLSXFormLoad(LD))
return;
break;
}
SDValue Offset = LD->getOffset();
if (Offset.getOpcode() == ISD::TargetConstant ||
Offset.getOpcode() == ISD::TargetGlobalAddress) {
unsigned Opcode;
bool isSExt = LD->getExtensionType() == ISD::SEXTLOAD;
if (LD->getValueType(0) != MVT::i64) {
// Handle PPC32 integer and normal FP loads.
assert((!isSExt || LoadedVT == MVT::i16) && "Invalid sext update load");
switch (LoadedVT.getSimpleVT().SimpleTy) {
default: llvm_unreachable("Invalid PPC load type!");
case MVT::f64: Opcode = PPC::LFDU; break;
case MVT::f32: Opcode = PPC::LFSU; break;
case MVT::i32: Opcode = PPC::LWZU; break;
case MVT::i16: Opcode = isSExt ? PPC::LHAU : PPC::LHZU; break;
case MVT::i1:
case MVT::i8: Opcode = PPC::LBZU; break;
}
} else {
assert(LD->getValueType(0) == MVT::i64 && "Unknown load result type!");
assert((!isSExt || LoadedVT == MVT::i16) && "Invalid sext update load");
switch (LoadedVT.getSimpleVT().SimpleTy) {
default: llvm_unreachable("Invalid PPC load type!");
case MVT::i64: Opcode = PPC::LDU; break;
case MVT::i32: Opcode = PPC::LWZU8; break;
case MVT::i16: Opcode = isSExt ? PPC::LHAU8 : PPC::LHZU8; break;
case MVT::i1:
case MVT::i8: Opcode = PPC::LBZU8; break;
}
}
SDValue Chain = LD->getChain();
SDValue Base = LD->getBasePtr();
SDValue Ops[] = { Offset, Base, Chain };
SDNode *MN = CurDAG->getMachineNode(
Opcode, dl, LD->getValueType(0),
PPCLowering->getPointerTy(CurDAG->getDataLayout()), MVT::Other, Ops);
transferMemOperands(N, MN);
ReplaceNode(N, MN);
return;
} else {
unsigned Opcode;
bool isSExt = LD->getExtensionType() == ISD::SEXTLOAD;
if (LD->getValueType(0) != MVT::i64) {
// Handle PPC32 integer and normal FP loads.
assert((!isSExt || LoadedVT == MVT::i16) && "Invalid sext update load");
switch (LoadedVT.getSimpleVT().SimpleTy) {
default: llvm_unreachable("Invalid PPC load type!");
case MVT::v4f64: Opcode = PPC::QVLFDUX; break; // QPX
case MVT::v4f32: Opcode = PPC::QVLFSUX; break; // QPX
case MVT::f64: Opcode = PPC::LFDUX; break;
case MVT::f32: Opcode = PPC::LFSUX; break;
case MVT::i32: Opcode = PPC::LWZUX; break;
case MVT::i16: Opcode = isSExt ? PPC::LHAUX : PPC::LHZUX; break;
case MVT::i1:
case MVT::i8: Opcode = PPC::LBZUX; break;
}
} else {
assert(LD->getValueType(0) == MVT::i64 && "Unknown load result type!");
assert((!isSExt || LoadedVT == MVT::i16 || LoadedVT == MVT::i32) &&
"Invalid sext update load");
switch (LoadedVT.getSimpleVT().SimpleTy) {
default: llvm_unreachable("Invalid PPC load type!");
case MVT::i64: Opcode = PPC::LDUX; break;
case MVT::i32: Opcode = isSExt ? PPC::LWAUX : PPC::LWZUX8; break;
case MVT::i16: Opcode = isSExt ? PPC::LHAUX8 : PPC::LHZUX8; break;
case MVT::i1:
case MVT::i8: Opcode = PPC::LBZUX8; break;
}
}
SDValue Chain = LD->getChain();
SDValue Base = LD->getBasePtr();
SDValue Ops[] = { Base, Offset, Chain };
SDNode *MN = CurDAG->getMachineNode(
Opcode, dl, LD->getValueType(0),
PPCLowering->getPointerTy(CurDAG->getDataLayout()), MVT::Other, Ops);
transferMemOperands(N, MN);
ReplaceNode(N, MN);
return;
}
}
case ISD::AND: {
unsigned Imm, Imm2, SH, MB, ME;
uint64_t Imm64;
// If this is an and of a value rotated between 0 and 31 bits and then and'd
// with a mask, emit rlwinm
if (isInt32Immediate(N->getOperand(1), Imm) &&
isRotateAndMask(N->getOperand(0).getNode(), Imm, false, SH, MB, ME)) {
SDValue Val = N->getOperand(0).getOperand(0);
SDValue Ops[] = { Val, getI32Imm(SH, dl), getI32Imm(MB, dl),
getI32Imm(ME, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return;
}
// If this is just a masked value where the input is not handled above, and
// is not a rotate-left (handled by a pattern in the .td file), emit rlwinm
if (isInt32Immediate(N->getOperand(1), Imm) &&
isRunOfOnes(Imm, MB, ME) &&
N->getOperand(0).getOpcode() != ISD::ROTL) {
SDValue Val = N->getOperand(0);
SDValue Ops[] = { Val, getI32Imm(0, dl), getI32Imm(MB, dl),
getI32Imm(ME, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return;
}
// If this is a 64-bit zero-extension mask, emit rldicl.
if (isInt64Immediate(N->getOperand(1).getNode(), Imm64) &&
isMask_64(Imm64)) {
SDValue Val = N->getOperand(0);
MB = 64 - countTrailingOnes(Imm64);
SH = 0;
if (Val.getOpcode() == ISD::ANY_EXTEND) {
auto Op0 = Val.getOperand(0);
if ( Op0.getOpcode() == ISD::SRL &&
isInt32Immediate(Op0.getOperand(1).getNode(), Imm) && Imm <= MB) {
auto ResultType = Val.getNode()->getValueType(0);
auto ImDef = CurDAG->getMachineNode(PPC::IMPLICIT_DEF, dl,
ResultType);
SDValue IDVal (ImDef, 0);
Val = SDValue(CurDAG->getMachineNode(PPC::INSERT_SUBREG, dl,
ResultType, IDVal, Op0.getOperand(0),
getI32Imm(1, dl)), 0);
SH = 64 - Imm;
}
}
// If the operand is a logical right shift, we can fold it into this
// instruction: rldicl(rldicl(x, 64-n, n), 0, mb) -> rldicl(x, 64-n, mb)
// for n <= mb. The right shift is really a left rotate followed by a
// mask, and this mask is a more-restrictive sub-mask of the mask implied
// by the shift.
if (Val.getOpcode() == ISD::SRL &&
isInt32Immediate(Val.getOperand(1).getNode(), Imm) && Imm <= MB) {
assert(Imm < 64 && "Illegal shift amount");
Val = Val.getOperand(0);
SH = 64 - Imm;
}
SDValue Ops[] = { Val, getI32Imm(SH, dl), getI32Imm(MB, dl) };
CurDAG->SelectNodeTo(N, PPC::RLDICL, MVT::i64, Ops);
return;
}
// If this is a negated 64-bit zero-extension mask,
// i.e. the immediate is a sequence of ones from most significant side
// and all zero for reminder, we should use rldicr.
if (isInt64Immediate(N->getOperand(1).getNode(), Imm64) &&
isMask_64(~Imm64)) {
SDValue Val = N->getOperand(0);
MB = 63 - countTrailingOnes(~Imm64);
SH = 0;
SDValue Ops[] = { Val, getI32Imm(SH, dl), getI32Imm(MB, dl) };
CurDAG->SelectNodeTo(N, PPC::RLDICR, MVT::i64, Ops);
return;
}
// AND X, 0 -> 0, not "rlwinm 32".
if (isInt32Immediate(N->getOperand(1), Imm) && (Imm == 0)) {
ReplaceUses(SDValue(N, 0), N->getOperand(1));
return;
}
// ISD::OR doesn't get all the bitfield insertion fun.
// (and (or x, c1), c2) where isRunOfOnes(~(c1^c2)) might be a
// bitfield insert.
if (isInt32Immediate(N->getOperand(1), Imm) &&
N->getOperand(0).getOpcode() == ISD::OR &&
isInt32Immediate(N->getOperand(0).getOperand(1), Imm2)) {
// The idea here is to check whether this is equivalent to:
// (c1 & m) | (x & ~m)
// where m is a run-of-ones mask. The logic here is that, for each bit in
// c1 and c2:
// - if both are 1, then the output will be 1.
// - if both are 0, then the output will be 0.
// - if the bit in c1 is 0, and the bit in c2 is 1, then the output will
// come from x.
// - if the bit in c1 is 1, and the bit in c2 is 0, then the output will
// be 0.
// If that last condition is never the case, then we can form m from the
// bits that are the same between c1 and c2.
unsigned MB, ME;
if (isRunOfOnes(~(Imm^Imm2), MB, ME) && !(~Imm & Imm2)) {
SDValue Ops[] = { N->getOperand(0).getOperand(0),
N->getOperand(0).getOperand(1),
getI32Imm(0, dl), getI32Imm(MB, dl),
getI32Imm(ME, dl) };
ReplaceNode(N, CurDAG->getMachineNode(PPC::RLWIMI, dl, MVT::i32, Ops));
return;
}
}
// Other cases are autogenerated.
break;
}
case ISD::OR: {
if (N->getValueType(0) == MVT::i32)
if (tryBitfieldInsert(N))
return;
int16_t Imm;
if (N->getOperand(0)->getOpcode() == ISD::FrameIndex &&
isIntS16Immediate(N->getOperand(1), Imm)) {
KnownBits LHSKnown = CurDAG->computeKnownBits(N->getOperand(0));
// If this is equivalent to an add, then we can fold it with the
// FrameIndex calculation.
if ((LHSKnown.Zero.getZExtValue()|~(uint64_t)Imm) == ~0ULL) {
selectFrameIndex(N, N->getOperand(0).getNode(), (int)Imm);
return;
}
}
// OR with a 32-bit immediate can be handled by ori + oris
// without creating an immediate in a GPR.
uint64_t Imm64 = 0;
bool IsPPC64 = PPCSubTarget->isPPC64();
if (IsPPC64 && isInt64Immediate(N->getOperand(1), Imm64) &&
(Imm64 & ~0xFFFFFFFFuLL) == 0) {
// If ImmHi (ImmHi) is zero, only one ori (oris) is generated later.
uint64_t ImmHi = Imm64 >> 16;
uint64_t ImmLo = Imm64 & 0xFFFF;
if (ImmHi != 0 && ImmLo != 0) {
SDNode *Lo = CurDAG->getMachineNode(PPC::ORI8, dl, MVT::i64,
N->getOperand(0),
getI16Imm(ImmLo, dl));
SDValue Ops1[] = { SDValue(Lo, 0), getI16Imm(ImmHi, dl)};
CurDAG->SelectNodeTo(N, PPC::ORIS8, MVT::i64, Ops1);
return;
}
}
// Other cases are autogenerated.
break;
}
case ISD::XOR: {
// XOR with a 32-bit immediate can be handled by xori + xoris
// without creating an immediate in a GPR.
uint64_t Imm64 = 0;
bool IsPPC64 = PPCSubTarget->isPPC64();
if (IsPPC64 && isInt64Immediate(N->getOperand(1), Imm64) &&
(Imm64 & ~0xFFFFFFFFuLL) == 0) {
// If ImmHi (ImmHi) is zero, only one xori (xoris) is generated later.
uint64_t ImmHi = Imm64 >> 16;
uint64_t ImmLo = Imm64 & 0xFFFF;
if (ImmHi != 0 && ImmLo != 0) {
SDNode *Lo = CurDAG->getMachineNode(PPC::XORI8, dl, MVT::i64,
N->getOperand(0),
getI16Imm(ImmLo, dl));
SDValue Ops1[] = { SDValue(Lo, 0), getI16Imm(ImmHi, dl)};
CurDAG->SelectNodeTo(N, PPC::XORIS8, MVT::i64, Ops1);
return;
}
}
break;
}
case ISD::ADD: {
int16_t Imm;
if (N->getOperand(0)->getOpcode() == ISD::FrameIndex &&
isIntS16Immediate(N->getOperand(1), Imm)) {
selectFrameIndex(N, N->getOperand(0).getNode(), (int)Imm);
return;
}
break;
}
case ISD::SHL: {
unsigned Imm, SH, MB, ME;
if (isOpcWithIntImmediate(N->getOperand(0).getNode(), ISD::AND, Imm) &&
isRotateAndMask(N, Imm, true, SH, MB, ME)) {
SDValue Ops[] = { N->getOperand(0).getOperand(0),
getI32Imm(SH, dl), getI32Imm(MB, dl),
getI32Imm(ME, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return;
}
// Other cases are autogenerated.
break;
}
case ISD::SRL: {
unsigned Imm, SH, MB, ME;
if (isOpcWithIntImmediate(N->getOperand(0).getNode(), ISD::AND, Imm) &&
isRotateAndMask(N, Imm, true, SH, MB, ME)) {
SDValue Ops[] = { N->getOperand(0).getOperand(0),
getI32Imm(SH, dl), getI32Imm(MB, dl),
getI32Imm(ME, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return;
}
// Other cases are autogenerated.
break;
}
// FIXME: Remove this once the ANDI glue bug is fixed:
case PPCISD::ANDIo_1_EQ_BIT:
case PPCISD::ANDIo_1_GT_BIT: {
if (!ANDIGlueBug)
break;
EVT InVT = N->getOperand(0).getValueType();
assert((InVT == MVT::i64 || InVT == MVT::i32) &&
"Invalid input type for ANDIo_1_EQ_BIT");
unsigned Opcode = (InVT == MVT::i64) ? PPC::ANDIo8 : PPC::ANDIo;
SDValue AndI(CurDAG->getMachineNode(Opcode, dl, InVT, MVT::Glue,
N->getOperand(0),
CurDAG->getTargetConstant(1, dl, InVT)),
0);
SDValue CR0Reg = CurDAG->getRegister(PPC::CR0, MVT::i32);
SDValue SRIdxVal =
CurDAG->getTargetConstant(N->getOpcode() == PPCISD::ANDIo_1_EQ_BIT ?
PPC::sub_eq : PPC::sub_gt, dl, MVT::i32);
CurDAG->SelectNodeTo(N, TargetOpcode::EXTRACT_SUBREG, MVT::i1, CR0Reg,
SRIdxVal, SDValue(AndI.getNode(), 1) /* glue */);
return;
}
case ISD::SELECT_CC: {
ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(4))->get();
EVT PtrVT =
CurDAG->getTargetLoweringInfo().getPointerTy(CurDAG->getDataLayout());
bool isPPC64 = (PtrVT == MVT::i64);
// If this is a select of i1 operands, we'll pattern match it.
if (PPCSubTarget->useCRBits() &&
N->getOperand(0).getValueType() == MVT::i1)
break;
if (PPCSubTarget->isISA3_0() && PPCSubTarget->isPPC64()) {
bool NeedSwapOps = false;
bool IsUnCmp = false;
if (mayUseP9Setb(N, CC, CurDAG, NeedSwapOps, IsUnCmp)) {
SDValue LHS = N->getOperand(0);
SDValue RHS = N->getOperand(1);
if (NeedSwapOps)
std::swap(LHS, RHS);
// Make use of SelectCC to generate the comparison to set CR bits, for
// equality comparisons having one literal operand, SelectCC probably
// doesn't need to materialize the whole literal and just use xoris to
// check it first, it leads the following comparison result can't
// exactly represent GT/LT relationship. So to avoid this we specify
// SETGT/SETUGT here instead of SETEQ.
SDValue GenCC =
SelectCC(LHS, RHS, IsUnCmp ? ISD::SETUGT : ISD::SETGT, dl);
CurDAG->SelectNodeTo(
N, N->getSimpleValueType(0) == MVT::i64 ? PPC::SETB8 : PPC::SETB,
N->getValueType(0), GenCC);
NumP9Setb++;
return;
}
}
// Handle the setcc cases here. select_cc lhs, 0, 1, 0, cc
if (!isPPC64)
if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N->getOperand(1)))
if (ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N->getOperand(2)))
if (ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N->getOperand(3)))
if (N1C->isNullValue() && N3C->isNullValue() &&
N2C->getZExtValue() == 1ULL && CC == ISD::SETNE &&
// FIXME: Implement this optzn for PPC64.
N->getValueType(0) == MVT::i32) {
SDNode *Tmp =
CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
N->getOperand(0), getI32Imm(~0U, dl));
CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, SDValue(Tmp, 0),
N->getOperand(0), SDValue(Tmp, 1));
return;
}
SDValue CCReg = SelectCC(N->getOperand(0), N->getOperand(1), CC, dl);
if (N->getValueType(0) == MVT::i1) {
// An i1 select is: (c & t) | (!c & f).
bool Inv;
unsigned Idx = getCRIdxForSetCC(CC, Inv);
unsigned SRI;
switch (Idx) {
default: llvm_unreachable("Invalid CC index");
case 0: SRI = PPC::sub_lt; break;
case 1: SRI = PPC::sub_gt; break;
case 2: SRI = PPC::sub_eq; break;
case 3: SRI = PPC::sub_un; break;
}
SDValue CCBit = CurDAG->getTargetExtractSubreg(SRI, dl, MVT::i1, CCReg);
SDValue NotCCBit(CurDAG->getMachineNode(PPC::CRNOR, dl, MVT::i1,
CCBit, CCBit), 0);
SDValue C = Inv ? NotCCBit : CCBit,
NotC = Inv ? CCBit : NotCCBit;
SDValue CAndT(CurDAG->getMachineNode(PPC::CRAND, dl, MVT::i1,
C, N->getOperand(2)), 0);
SDValue NotCAndF(CurDAG->getMachineNode(PPC::CRAND, dl, MVT::i1,
NotC, N->getOperand(3)), 0);
CurDAG->SelectNodeTo(N, PPC::CROR, MVT::i1, CAndT, NotCAndF);
return;
}
unsigned BROpc = getPredicateForSetCC(CC);
unsigned SelectCCOp;
if (N->getValueType(0) == MVT::i32)
SelectCCOp = PPC::SELECT_CC_I4;
else if (N->getValueType(0) == MVT::i64)
SelectCCOp = PPC::SELECT_CC_I8;
else if (N->getValueType(0) == MVT::f32) {
if (PPCSubTarget->hasP8Vector())
SelectCCOp = PPC::SELECT_CC_VSSRC;
else if (PPCSubTarget->hasSPE())
SelectCCOp = PPC::SELECT_CC_SPE4;
else
SelectCCOp = PPC::SELECT_CC_F4;
} else if (N->getValueType(0) == MVT::f64) {
if (PPCSubTarget->hasVSX())
SelectCCOp = PPC::SELECT_CC_VSFRC;
else if (PPCSubTarget->hasSPE())
SelectCCOp = PPC::SELECT_CC_SPE;
else
SelectCCOp = PPC::SELECT_CC_F8;
} else if (N->getValueType(0) == MVT::f128)
SelectCCOp = PPC::SELECT_CC_F16;
else if (PPCSubTarget->hasSPE())
SelectCCOp = PPC::SELECT_CC_SPE;
else if (PPCSubTarget->hasQPX() && N->getValueType(0) == MVT::v4f64)
SelectCCOp = PPC::SELECT_CC_QFRC;
else if (PPCSubTarget->hasQPX() && N->getValueType(0) == MVT::v4f32)
SelectCCOp = PPC::SELECT_CC_QSRC;
else if (PPCSubTarget->hasQPX() && N->getValueType(0) == MVT::v4i1)
SelectCCOp = PPC::SELECT_CC_QBRC;
else if (N->getValueType(0) == MVT::v2f64 ||
N->getValueType(0) == MVT::v2i64)
SelectCCOp = PPC::SELECT_CC_VSRC;
else
SelectCCOp = PPC::SELECT_CC_VRRC;
SDValue Ops[] = { CCReg, N->getOperand(2), N->getOperand(3),
getI32Imm(BROpc, dl) };
CurDAG->SelectNodeTo(N, SelectCCOp, N->getValueType(0), Ops);
return;
}
case ISD::VECTOR_SHUFFLE:
if (PPCSubTarget->hasVSX() && (N->getValueType(0) == MVT::v2f64 ||
N->getValueType(0) == MVT::v2i64)) {
ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
SDValue Op1 = N->getOperand(SVN->getMaskElt(0) < 2 ? 0 : 1),
Op2 = N->getOperand(SVN->getMaskElt(1) < 2 ? 0 : 1);
unsigned DM[2];
for (int i = 0; i < 2; ++i)
if (SVN->getMaskElt(i) <= 0 || SVN->getMaskElt(i) == 2)
DM[i] = 0;
else
DM[i] = 1;
if (Op1 == Op2 && DM[0] == 0 && DM[1] == 0 &&
Op1.getOpcode() == ISD::SCALAR_TO_VECTOR &&
isa<LoadSDNode>(Op1.getOperand(0))) {
LoadSDNode *LD = cast<LoadSDNode>(Op1.getOperand(0));
SDValue Base, Offset;
if (LD->isUnindexed() && LD->hasOneUse() && Op1.hasOneUse() &&
(LD->getMemoryVT() == MVT::f64 ||
LD->getMemoryVT() == MVT::i64) &&
SelectAddrIdxOnly(LD->getBasePtr(), Base, Offset)) {
SDValue Chain = LD->getChain();
SDValue Ops[] = { Base, Offset, Chain };
MachineMemOperand *MemOp = LD->getMemOperand();
SDNode *NewN = CurDAG->SelectNodeTo(N, PPC::LXVDSX,
N->getValueType(0), Ops);
CurDAG->setNodeMemRefs(cast<MachineSDNode>(NewN), {MemOp});
return;
}
}
// For little endian, we must swap the input operands and adjust
// the mask elements (reverse and invert them).
if (PPCSubTarget->isLittleEndian()) {
std::swap(Op1, Op2);
unsigned tmp = DM[0];
DM[0] = 1 - DM[1];
DM[1] = 1 - tmp;
}
SDValue DMV = CurDAG->getTargetConstant(DM[1] | (DM[0] << 1), dl,
MVT::i32);
SDValue Ops[] = { Op1, Op2, DMV };
CurDAG->SelectNodeTo(N, PPC::XXPERMDI, N->getValueType(0), Ops);
return;
}
break;
case PPCISD::BDNZ:
case PPCISD::BDZ: {
bool IsPPC64 = PPCSubTarget->isPPC64();
SDValue Ops[] = { N->getOperand(1), N->getOperand(0) };
CurDAG->SelectNodeTo(N, N->getOpcode() == PPCISD::BDNZ
? (IsPPC64 ? PPC::BDNZ8 : PPC::BDNZ)
: (IsPPC64 ? PPC::BDZ8 : PPC::BDZ),
MVT::Other, Ops);
return;
}
case PPCISD::COND_BRANCH: {
// Op #0 is the Chain.
// Op #1 is the PPC::PRED_* number.
// Op #2 is the CR#
// Op #3 is the Dest MBB
// Op #4 is the Flag.
// Prevent PPC::PRED_* from being selected into LI.
unsigned PCC = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
if (EnableBranchHint)
PCC |= getBranchHint(PCC, FuncInfo, N->getOperand(3));
SDValue Pred = getI32Imm(PCC, dl);
SDValue Ops[] = { Pred, N->getOperand(2), N->getOperand(3),
N->getOperand(0), N->getOperand(4) };
CurDAG->SelectNodeTo(N, PPC::BCC, MVT::Other, Ops);
return;
}
case ISD::BR_CC: {
ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(1))->get();
unsigned PCC = getPredicateForSetCC(CC);
if (N->getOperand(2).getValueType() == MVT::i1) {
unsigned Opc;
bool Swap;
switch (PCC) {
default: llvm_unreachable("Unexpected Boolean-operand predicate");
case PPC::PRED_LT: Opc = PPC::CRANDC; Swap = true; break;
case PPC::PRED_LE: Opc = PPC::CRORC; Swap = true; break;
case PPC::PRED_EQ: Opc = PPC::CREQV; Swap = false; break;
case PPC::PRED_GE: Opc = PPC::CRORC; Swap = false; break;
case PPC::PRED_GT: Opc = PPC::CRANDC; Swap = false; break;
case PPC::PRED_NE: Opc = PPC::CRXOR; Swap = false; break;
}
// A signed comparison of i1 values produces the opposite result to an
// unsigned one if the condition code includes less-than or greater-than.
// This is because 1 is the most negative signed i1 number and the most
// positive unsigned i1 number. The CR-logical operations used for such
// comparisons are non-commutative so for signed comparisons vs. unsigned
// ones, the input operands just need to be swapped.
if (ISD::isSignedIntSetCC(CC))
Swap = !Swap;
SDValue BitComp(CurDAG->getMachineNode(Opc, dl, MVT::i1,
N->getOperand(Swap ? 3 : 2),
N->getOperand(Swap ? 2 : 3)), 0);
CurDAG->SelectNodeTo(N, PPC::BC, MVT::Other, BitComp, N->getOperand(4),
N->getOperand(0));
return;
}
if (EnableBranchHint)
PCC |= getBranchHint(PCC, FuncInfo, N->getOperand(4));
SDValue CondCode = SelectCC(N->getOperand(2), N->getOperand(3), CC, dl);
SDValue Ops[] = { getI32Imm(PCC, dl), CondCode,
N->getOperand(4), N->getOperand(0) };
CurDAG->SelectNodeTo(N, PPC::BCC, MVT::Other, Ops);
return;
}
case ISD::BRIND: {
// FIXME: Should custom lower this.
SDValue Chain = N->getOperand(0);
SDValue Target = N->getOperand(1);
unsigned Opc = Target.getValueType() == MVT::i32 ? PPC::MTCTR : PPC::MTCTR8;
unsigned Reg = Target.getValueType() == MVT::i32 ? PPC::BCTR : PPC::BCTR8;
Chain = SDValue(CurDAG->getMachineNode(Opc, dl, MVT::Glue, Target,
Chain), 0);
CurDAG->SelectNodeTo(N, Reg, MVT::Other, Chain);
return;
}
case PPCISD::TOC_ENTRY: {
const bool isPPC64 = PPCSubTarget->isPPC64();
const bool isELFABI = PPCSubTarget->isSVR4ABI();
const bool isAIXABI = PPCSubTarget->isAIXABI();
assert(!PPCSubTarget->isDarwin() && "TOC is an ELF/XCOFF construct");
// PowerPC only support small, medium and large code model.
const CodeModel::Model CModel = TM.getCodeModel();
assert(!(CModel == CodeModel::Tiny || CModel == CodeModel::Kernel) &&
"PowerPC doesn't support tiny or kernel code models.");
if (isAIXABI && CModel == CodeModel::Medium)
report_fatal_error("Medium code model is not supported on AIX.");
// For 64-bit small code model, we allow SelectCodeCommon to handle this,
// selecting one of LDtoc, LDtocJTI, LDtocCPT, and LDtocBA.
if (isPPC64 && CModel == CodeModel::Small)
break;
// Handle 32-bit small code model.
if (!isPPC64) {
// Transforms the ISD::TOC_ENTRY node to a PPCISD::LWZtoc.
auto replaceWithLWZtoc = [this, &dl](SDNode *TocEntry) {
SDValue GA = TocEntry->getOperand(0);
SDValue TocBase = TocEntry->getOperand(1);
SDNode *MN = CurDAG->getMachineNode(PPC::LWZtoc, dl, MVT::i32, GA,
TocBase);
transferMemOperands(TocEntry, MN);
ReplaceNode(TocEntry, MN);
};
if (isELFABI) {
assert(TM.isPositionIndependent() &&
"32-bit ELF can only have TOC entries in position independent"
" code.");
// 32-bit ELF always uses a small code model toc access.
replaceWithLWZtoc(N);
return;
}
if (isAIXABI && CModel == CodeModel::Small) {
replaceWithLWZtoc(N);
return;
}
}
assert(CModel != CodeModel::Small && "All small code models handled.");
assert((isPPC64 || (isAIXABI && !isPPC64)) && "We are dealing with 64-bit"
" ELF/AIX or 32-bit AIX in the following.");
// Transforms the ISD::TOC_ENTRY node for 32-bit AIX large code model mode
// or 64-bit medium (ELF-only) or large (ELF and AIX) code model code. We
// generate two instructions as described below. The first source operand
// is a symbol reference. If it must be toc-referenced according to
// PPCSubTarget, we generate:
// [32-bit AIX]
// LWZtocL(@sym, ADDIStocHA(%r2, @sym))
// [64-bit ELF/AIX]
// LDtocL(@sym, ADDIStocHA8(%x2, @sym))
// Otherwise we generate:
// ADDItocL(ADDIStocHA8(%x2, @sym), @sym)
SDValue GA = N->getOperand(0);
SDValue TOCbase = N->getOperand(1);
EVT VT = isPPC64 ? MVT::i64 : MVT::i32;
SDNode *Tmp = CurDAG->getMachineNode(
isPPC64 ? PPC::ADDIStocHA8 : PPC::ADDIStocHA, dl, VT, TOCbase, GA);
if (PPCLowering->isAccessedAsGotIndirect(GA)) {
// If it is accessed as got-indirect, we need an extra LWZ/LD to load
// the address.
SDNode *MN = CurDAG->getMachineNode(
isPPC64 ? PPC::LDtocL : PPC::LWZtocL, dl, VT, GA, SDValue(Tmp, 0));
transferMemOperands(N, MN);
ReplaceNode(N, MN);
return;
}
// Build the address relative to the TOC-pointer.
ReplaceNode(N, CurDAG->getMachineNode(PPC::ADDItocL, dl, MVT::i64,
SDValue(Tmp, 0), GA));
return;
}
case PPCISD::PPC32_PICGOT:
// Generate a PIC-safe GOT reference.
assert(PPCSubTarget->is32BitELFABI() &&
"PPCISD::PPC32_PICGOT is only supported for 32-bit SVR4");
CurDAG->SelectNodeTo(N, PPC::PPC32PICGOT,
PPCLowering->getPointerTy(CurDAG->getDataLayout()),
MVT::i32);
return;
case PPCISD::VADD_SPLAT: {
// This expands into one of three sequences, depending on whether
// the first operand is odd or even, positive or negative.
assert(isa<ConstantSDNode>(N->getOperand(0)) &&
isa<ConstantSDNode>(N->getOperand(1)) &&
"Invalid operand on VADD_SPLAT!");
int Elt = N->getConstantOperandVal(0);
int EltSize = N->getConstantOperandVal(1);
unsigned Opc1, Opc2, Opc3;
EVT VT;
if (EltSize == 1) {
Opc1 = PPC::VSPLTISB;
Opc2 = PPC::VADDUBM;
Opc3 = PPC::VSUBUBM;
VT = MVT::v16i8;
} else if (EltSize == 2) {
Opc1 = PPC::VSPLTISH;
Opc2 = PPC::VADDUHM;
Opc3 = PPC::VSUBUHM;
VT = MVT::v8i16;
} else {
assert(EltSize == 4 && "Invalid element size on VADD_SPLAT!");
Opc1 = PPC::VSPLTISW;
Opc2 = PPC::VADDUWM;
Opc3 = PPC::VSUBUWM;
VT = MVT::v4i32;
}
if ((Elt & 1) == 0) {
// Elt is even, in the range [-32,-18] + [16,30].
//
// Convert: VADD_SPLAT elt, size
// Into: tmp = VSPLTIS[BHW] elt
// VADDU[BHW]M tmp, tmp
// Where: [BHW] = B for size = 1, H for size = 2, W for size = 4
SDValue EltVal = getI32Imm(Elt >> 1, dl);
SDNode *Tmp = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
SDValue TmpVal = SDValue(Tmp, 0);
ReplaceNode(N, CurDAG->getMachineNode(Opc2, dl, VT, TmpVal, TmpVal));
return;
} else if (Elt > 0) {
// Elt is odd and positive, in the range [17,31].
//
// Convert: VADD_SPLAT elt, size
// Into: tmp1 = VSPLTIS[BHW] elt-16
// tmp2 = VSPLTIS[BHW] -16
// VSUBU[BHW]M tmp1, tmp2
SDValue EltVal = getI32Imm(Elt - 16, dl);
SDNode *Tmp1 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
EltVal = getI32Imm(-16, dl);
SDNode *Tmp2 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
ReplaceNode(N, CurDAG->getMachineNode(Opc3, dl, VT, SDValue(Tmp1, 0),
SDValue(Tmp2, 0)));
return;
} else {
// Elt is odd and negative, in the range [-31,-17].
//
// Convert: VADD_SPLAT elt, size
// Into: tmp1 = VSPLTIS[BHW] elt+16
// tmp2 = VSPLTIS[BHW] -16
// VADDU[BHW]M tmp1, tmp2
SDValue EltVal = getI32Imm(Elt + 16, dl);
SDNode *Tmp1 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
EltVal = getI32Imm(-16, dl);
SDNode *Tmp2 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
ReplaceNode(N, CurDAG->getMachineNode(Opc2, dl, VT, SDValue(Tmp1, 0),
SDValue(Tmp2, 0)));
return;
}
}
}
SelectCode(N);
}
// If the target supports the cmpb instruction, do the idiom recognition here.
// We don't do this as a DAG combine because we don't want to do it as nodes
// are being combined (because we might miss part of the eventual idiom). We
// don't want to do it during instruction selection because we want to reuse
// the logic for lowering the masking operations already part of the
// instruction selector.
SDValue PPCDAGToDAGISel::combineToCMPB(SDNode *N) {
SDLoc dl(N);
assert(N->getOpcode() == ISD::OR &&
"Only OR nodes are supported for CMPB");
SDValue Res;
if (!PPCSubTarget->hasCMPB())
return Res;
if (N->getValueType(0) != MVT::i32 &&
N->getValueType(0) != MVT::i64)
return Res;
EVT VT = N->getValueType(0);
SDValue RHS, LHS;
bool BytesFound[8] = {false, false, false, false, false, false, false, false};
uint64_t Mask = 0, Alt = 0;
auto IsByteSelectCC = [this](SDValue O, unsigned &b,
uint64_t &Mask, uint64_t &Alt,
SDValue &LHS, SDValue &RHS) {
if (O.getOpcode() != ISD::SELECT_CC)
return false;
ISD::CondCode CC = cast<CondCodeSDNode>(O.getOperand(4))->get();
if (!isa<ConstantSDNode>(O.getOperand(2)) ||
!isa<ConstantSDNode>(O.getOperand(3)))
return false;
uint64_t PM = O.getConstantOperandVal(2);
uint64_t PAlt = O.getConstantOperandVal(3);
for (b = 0; b < 8; ++b) {
uint64_t Mask = UINT64_C(0xFF) << (8*b);
if (PM && (PM & Mask) == PM && (PAlt & Mask) == PAlt)
break;
}
if (b == 8)
return false;
Mask |= PM;
Alt |= PAlt;
if (!isa<ConstantSDNode>(O.getOperand(1)) ||
O.getConstantOperandVal(1) != 0) {
SDValue Op0 = O.getOperand(0), Op1 = O.getOperand(1);
if (Op0.getOpcode() == ISD::TRUNCATE)
Op0 = Op0.getOperand(0);
if (Op1.getOpcode() == ISD::TRUNCATE)
Op1 = Op1.getOperand(0);
if (Op0.getOpcode() == ISD::SRL && Op1.getOpcode() == ISD::SRL &&
Op0.getOperand(1) == Op1.getOperand(1) && CC == ISD::SETEQ &&
isa<ConstantSDNode>(Op0.getOperand(1))) {
unsigned Bits = Op0.getValueSizeInBits();
if (b != Bits/8-1)
return false;
if (Op0.getConstantOperandVal(1) != Bits-8)
return false;
LHS = Op0.getOperand(0);
RHS = Op1.getOperand(0);
return true;
}
// When we have small integers (i16 to be specific), the form present
// post-legalization uses SETULT in the SELECT_CC for the
// higher-order byte, depending on the fact that the
// even-higher-order bytes are known to all be zero, for example:
// select_cc (xor $lhs, $rhs), 256, 65280, 0, setult
// (so when the second byte is the same, because all higher-order
// bits from bytes 3 and 4 are known to be zero, the result of the
// xor can be at most 255)
if (Op0.getOpcode() == ISD::XOR && CC == ISD::SETULT &&
isa<ConstantSDNode>(O.getOperand(1))) {
uint64_t ULim = O.getConstantOperandVal(1);
if (ULim != (UINT64_C(1) << b*8))
return false;
// Now we need to make sure that the upper bytes are known to be
// zero.
unsigned Bits = Op0.getValueSizeInBits();
if (!CurDAG->MaskedValueIsZero(
Op0, APInt::getHighBitsSet(Bits, Bits - (b + 1) * 8)))
return false;
LHS = Op0.getOperand(0);
RHS = Op0.getOperand(1);
return true;
}
return false;
}
if (CC != ISD::SETEQ)
return false;
SDValue Op = O.getOperand(0);
if (Op.getOpcode() == ISD::AND) {
if (!isa<ConstantSDNode>(Op.getOperand(1)))
return false;
if (Op.getConstantOperandVal(1) != (UINT64_C(0xFF) << (8*b)))
return false;
SDValue XOR = Op.getOperand(0);
if (XOR.getOpcode() == ISD::TRUNCATE)
XOR = XOR.getOperand(0);
if (XOR.getOpcode() != ISD::XOR)
return false;
LHS = XOR.getOperand(0);
RHS = XOR.getOperand(1);
return true;
} else if (Op.getOpcode() == ISD::SRL) {
if (!isa<ConstantSDNode>(Op.getOperand(1)))
return false;
unsigned Bits = Op.getValueSizeInBits();
if (b != Bits/8-1)
return false;
if (Op.getConstantOperandVal(1) != Bits-8)
return false;
SDValue XOR = Op.getOperand(0);
if (XOR.getOpcode() == ISD::TRUNCATE)
XOR = XOR.getOperand(0);
if (XOR.getOpcode() != ISD::XOR)
return false;
LHS = XOR.getOperand(0);
RHS = XOR.getOperand(1);
return true;
}
return false;
};
SmallVector<SDValue, 8> Queue(1, SDValue(N, 0));
while (!Queue.empty()) {
SDValue V = Queue.pop_back_val();
for (const SDValue &O : V.getNode()->ops()) {
unsigned b = 0;
uint64_t M = 0, A = 0;
SDValue OLHS, ORHS;
if (O.getOpcode() == ISD::OR) {
Queue.push_back(O);
} else if (IsByteSelectCC(O, b, M, A, OLHS, ORHS)) {
if (!LHS) {
LHS = OLHS;
RHS = ORHS;
BytesFound[b] = true;
Mask |= M;
Alt |= A;
} else if ((LHS == ORHS && RHS == OLHS) ||
(RHS == ORHS && LHS == OLHS)) {
BytesFound[b] = true;
Mask |= M;
Alt |= A;
} else {
return Res;
}
} else {
return Res;
}
}
}
unsigned LastB = 0, BCnt = 0;
for (unsigned i = 0; i < 8; ++i)
if (BytesFound[LastB]) {
++BCnt;
LastB = i;
}
if (!LastB || BCnt < 2)
return Res;
// Because we'll be zero-extending the output anyway if don't have a specific
// value for each input byte (via the Mask), we can 'anyext' the inputs.
if (LHS.getValueType() != VT) {
LHS = CurDAG->getAnyExtOrTrunc(LHS, dl, VT);
RHS = CurDAG->getAnyExtOrTrunc(RHS, dl, VT);
}
Res = CurDAG->getNode(PPCISD::CMPB, dl, VT, LHS, RHS);
bool NonTrivialMask = ((int64_t) Mask) != INT64_C(-1);
if (NonTrivialMask && !Alt) {
// Res = Mask & CMPB
Res = CurDAG->getNode(ISD::AND, dl, VT, Res,
CurDAG->getConstant(Mask, dl, VT));
} else if (Alt) {
// Res = (CMPB & Mask) | (~CMPB & Alt)
// Which, as suggested here:
// https://graphics.stanford.edu/~seander/bithacks.html#MaskedMerge
// can be written as:
// Res = Alt ^ ((Alt ^ Mask) & CMPB)
// useful because the (Alt ^ Mask) can be pre-computed.
Res = CurDAG->getNode(ISD::AND, dl, VT, Res,
CurDAG->getConstant(Mask ^ Alt, dl, VT));
Res = CurDAG->getNode(ISD::XOR, dl, VT, Res,
CurDAG->getConstant(Alt, dl, VT));
}
return Res;
}
// When CR bit registers are enabled, an extension of an i1 variable to a i32
// or i64 value is lowered in terms of a SELECT_I[48] operation, and thus
// involves constant materialization of a 0 or a 1 or both. If the result of
// the extension is then operated upon by some operator that can be constant
// folded with a constant 0 or 1, and that constant can be materialized using
// only one instruction (like a zero or one), then we should fold in those
// operations with the select.
void PPCDAGToDAGISel::foldBoolExts(SDValue &Res, SDNode *&N) {
if (!PPCSubTarget->useCRBits())
return;
if (N->getOpcode() != ISD::ZERO_EXTEND &&
N->getOpcode() != ISD::SIGN_EXTEND &&
N->getOpcode() != ISD::ANY_EXTEND)
return;
if (N->getOperand(0).getValueType() != MVT::i1)
return;
if (!N->hasOneUse())
return;
SDLoc dl(N);
EVT VT = N->getValueType(0);
SDValue Cond = N->getOperand(0);
SDValue ConstTrue =
CurDAG->getConstant(N->getOpcode() == ISD::SIGN_EXTEND ? -1 : 1, dl, VT);
SDValue ConstFalse = CurDAG->getConstant(0, dl, VT);
do {
SDNode *User = *N->use_begin();
if (User->getNumOperands() != 2)
break;
auto TryFold = [this, N, User, dl](SDValue Val) {
SDValue UserO0 = User->getOperand(0), UserO1 = User->getOperand(1);
SDValue O0 = UserO0.getNode() == N ? Val : UserO0;
SDValue O1 = UserO1.getNode() == N ? Val : UserO1;
return CurDAG->FoldConstantArithmetic(User->getOpcode(), dl,
User->getValueType(0),
O0.getNode(), O1.getNode());
};
// FIXME: When the semantics of the interaction between select and undef
// are clearly defined, it may turn out to be unnecessary to break here.
SDValue TrueRes = TryFold(ConstTrue);
if (!TrueRes || TrueRes.isUndef())
break;
SDValue FalseRes = TryFold(ConstFalse);
if (!FalseRes || FalseRes.isUndef())
break;
// For us to materialize these using one instruction, we must be able to
// represent them as signed 16-bit integers.
uint64_t True = cast<ConstantSDNode>(TrueRes)->getZExtValue(),
False = cast<ConstantSDNode>(FalseRes)->getZExtValue();
if (!isInt<16>(True) || !isInt<16>(False))
break;
// We can replace User with a new SELECT node, and try again to see if we
// can fold the select with its user.
Res = CurDAG->getSelect(dl, User->getValueType(0), Cond, TrueRes, FalseRes);
N = User;
ConstTrue = TrueRes;
ConstFalse = FalseRes;
} while (N->hasOneUse());
}
void PPCDAGToDAGISel::PreprocessISelDAG() {
SelectionDAG::allnodes_iterator Position = CurDAG->allnodes_end();
bool MadeChange = false;
while (Position != CurDAG->allnodes_begin()) {
SDNode *N = &*--Position;
if (N->use_empty())
continue;
SDValue Res;
switch (N->getOpcode()) {
default: break;
case ISD::OR:
Res = combineToCMPB(N);
break;
}
if (!Res)
foldBoolExts(Res, N);
if (Res) {
LLVM_DEBUG(dbgs() << "PPC DAG preprocessing replacing:\nOld: ");
LLVM_DEBUG(N->dump(CurDAG));
LLVM_DEBUG(dbgs() << "\nNew: ");
LLVM_DEBUG(Res.getNode()->dump(CurDAG));
LLVM_DEBUG(dbgs() << "\n");
CurDAG->ReplaceAllUsesOfValueWith(SDValue(N, 0), Res);
MadeChange = true;
}
}
if (MadeChange)
CurDAG->RemoveDeadNodes();
}
/// PostprocessISelDAG - Perform some late peephole optimizations
/// on the DAG representation.
void PPCDAGToDAGISel::PostprocessISelDAG() {
// Skip peepholes at -O0.
if (TM.getOptLevel() == CodeGenOpt::None)
return;
PeepholePPC64();
PeepholeCROps();
PeepholePPC64ZExt();
}
// Check if all users of this node will become isel where the second operand
// is the constant zero. If this is so, and if we can negate the condition,
// then we can flip the true and false operands. This will allow the zero to
// be folded with the isel so that we don't need to materialize a register
// containing zero.
bool PPCDAGToDAGISel::AllUsersSelectZero(SDNode *N) {
for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
UI != UE; ++UI) {
SDNode *User = *UI;
if (!User->isMachineOpcode())
return false;
if (User->getMachineOpcode() != PPC::SELECT_I4 &&
User->getMachineOpcode() != PPC::SELECT_I8)
return false;
SDNode *Op2 = User->getOperand(2).getNode();
if (!Op2->isMachineOpcode())
return false;
if (Op2->getMachineOpcode() != PPC::LI &&
Op2->getMachineOpcode() != PPC::LI8)
return false;
ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op2->getOperand(0));
if (!C)
return false;
if (!C->isNullValue())
return false;
}
return true;
}
void PPCDAGToDAGISel::SwapAllSelectUsers(SDNode *N) {
SmallVector<SDNode *, 4> ToReplace;
for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
UI != UE; ++UI) {
SDNode *User = *UI;
assert((User->getMachineOpcode() == PPC::SELECT_I4 ||
User->getMachineOpcode() == PPC::SELECT_I8) &&
"Must have all select users");
ToReplace.push_back(User);
}
for (SmallVector<SDNode *, 4>::iterator UI = ToReplace.begin(),
UE = ToReplace.end(); UI != UE; ++UI) {
SDNode *User = *UI;
SDNode *ResNode =
CurDAG->getMachineNode(User->getMachineOpcode(), SDLoc(User),
User->getValueType(0), User->getOperand(0),
User->getOperand(2),
User->getOperand(1));
LLVM_DEBUG(dbgs() << "CR Peephole replacing:\nOld: ");
LLVM_DEBUG(User->dump(CurDAG));
LLVM_DEBUG(dbgs() << "\nNew: ");
LLVM_DEBUG(ResNode->dump(CurDAG));
LLVM_DEBUG(dbgs() << "\n");
ReplaceUses(User, ResNode);
}
}
void PPCDAGToDAGISel::PeepholeCROps() {
bool IsModified;
do {
IsModified = false;
for (SDNode &Node : CurDAG->allnodes()) {
MachineSDNode *MachineNode = dyn_cast<MachineSDNode>(&Node);
if (!MachineNode || MachineNode->use_empty())
continue;
SDNode *ResNode = MachineNode;
bool Op1Set = false, Op1Unset = false,
Op1Not = false,
Op2Set = false, Op2Unset = false,
Op2Not = false;
unsigned Opcode = MachineNode->getMachineOpcode();
switch (Opcode) {
default: break;
case PPC::CRAND:
case PPC::CRNAND:
case PPC::CROR:
case PPC::CRXOR:
case PPC::CRNOR:
case PPC::CREQV:
case PPC::CRANDC:
case PPC::CRORC: {
SDValue Op = MachineNode->getOperand(1);
if (Op.isMachineOpcode()) {
if (Op.getMachineOpcode() == PPC::CRSET)
Op2Set = true;
else if (Op.getMachineOpcode() == PPC::CRUNSET)
Op2Unset = true;
else if (Op.getMachineOpcode() == PPC::CRNOR &&
Op.getOperand(0) == Op.getOperand(1))
Op2Not = true;
}
LLVM_FALLTHROUGH;
}
case PPC::BC:
case PPC::BCn:
case PPC::SELECT_I4:
case PPC::SELECT_I8:
case PPC::SELECT_F4:
case PPC::SELECT_F8:
case PPC::SELECT_QFRC:
case PPC::SELECT_QSRC:
case PPC::SELECT_QBRC:
case PPC::SELECT_SPE:
case PPC::SELECT_SPE4:
case PPC::SELECT_VRRC:
case PPC::SELECT_VSFRC:
case PPC::SELECT_VSSRC:
case PPC::SELECT_VSRC: {
SDValue Op = MachineNode->getOperand(0);
if (Op.isMachineOpcode()) {
if (Op.getMachineOpcode() == PPC::CRSET)
Op1Set = true;
else if (Op.getMachineOpcode() == PPC::CRUNSET)
Op1Unset = true;
else if (Op.getMachineOpcode() == PPC::CRNOR &&
Op.getOperand(0) == Op.getOperand(1))
Op1Not = true;
}
}
break;
}
bool SelectSwap = false;
switch (Opcode) {
default: break;
case PPC::CRAND:
if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
// x & x = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Set)
// 1 & y = y
ResNode = MachineNode->getOperand(1).getNode();
else if (Op2Set)
// x & 1 = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Unset || Op2Unset)
// x & 0 = 0 & y = 0
ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Not)
// ~x & y = andc(y, x)
ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(0).
getOperand(0));
else if (Op2Not)
// x & ~y = andc(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1).
getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CRNAND, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1));
SelectSwap = true;
}
break;
case PPC::CRNAND:
if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
// nand(x, x) -> nor(x, x)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(0));
else if (Op1Set)
// nand(1, y) -> nor(y, y)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(1));
else if (Op2Set)
// nand(x, 1) -> nor(x, x)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(0));
else if (Op1Unset || Op2Unset)
// nand(x, 0) = nand(0, y) = 1
ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Not)
// nand(~x, y) = ~(~x & y) = x | ~y = orc(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(1));
else if (Op2Not)
// nand(x, ~y) = ~x | y = orc(y, x)
ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1).
getOperand(0),
MachineNode->getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CRAND, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1));
SelectSwap = true;
}
break;
case PPC::CROR:
if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
// x | x = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Set || Op2Set)
// x | 1 = 1 | y = 1
ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Unset)
// 0 | y = y
ResNode = MachineNode->getOperand(1).getNode();
else if (Op2Unset)
// x | 0 = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Not)
// ~x | y = orc(y, x)
ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(0).
getOperand(0));
else if (Op2Not)
// x | ~y = orc(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1).
getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1));
SelectSwap = true;
}
break;
case PPC::CRXOR:
if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
// xor(x, x) = 0
ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Set)
// xor(1, y) -> nor(y, y)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(1));
else if (Op2Set)
// xor(x, 1) -> nor(x, x)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(0));
else if (Op1Unset)
// xor(0, y) = y
ResNode = MachineNode->getOperand(1).getNode();
else if (Op2Unset)
// xor(x, 0) = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Not)
// xor(~x, y) = eqv(x, y)
ResNode = CurDAG->getMachineNode(PPC::CREQV, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(1));
else if (Op2Not)
// xor(x, ~y) = eqv(x, y)
ResNode = CurDAG->getMachineNode(PPC::CREQV, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1).
getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CREQV, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1));
SelectSwap = true;
}
break;
case PPC::CRNOR:
if (Op1Set || Op2Set)
// nor(1, y) -> 0
ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Unset)
// nor(0, y) = ~y -> nor(y, y)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(1));
else if (Op2Unset)
// nor(x, 0) = ~x
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(0));
else if (Op1Not)
// nor(~x, y) = andc(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(1));
else if (Op2Not)
// nor(x, ~y) = andc(y, x)
ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1).
getOperand(0),
MachineNode->getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CROR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1));
SelectSwap = true;
}
break;
case PPC::CREQV:
if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
// eqv(x, x) = 1
ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Set)
// eqv(1, y) = y
ResNode = MachineNode->getOperand(1).getNode();
else if (Op2Set)
// eqv(x, 1) = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Unset)
// eqv(0, y) = ~y -> nor(y, y)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(1));
else if (Op2Unset)
// eqv(x, 0) = ~x
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(0));
else if (Op1Not)
// eqv(~x, y) = xor(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRXOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(1));
else if (Op2Not)
// eqv(x, ~y) = xor(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRXOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1).
getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CRXOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1));
SelectSwap = true;
}
break;
case PPC::CRANDC:
if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
// andc(x, x) = 0
ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Set)
// andc(1, y) = ~y
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(1));
else if (Op1Unset || Op2Set)
// andc(0, y) = andc(x, 1) = 0
ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
MVT::i1);
else if (Op2Unset)
// andc(x, 0) = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Not)
// andc(~x, y) = ~(x | y) = nor(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(1));
else if (Op2Not)
// andc(x, ~y) = x & y
ResNode = CurDAG->getMachineNode(PPC::CRAND, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1).
getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(0));
SelectSwap = true;
}
break;
case PPC::CRORC:
if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
// orc(x, x) = 1
ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Set || Op2Unset)
// orc(1, y) = orc(x, 0) = 1
ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
MVT::i1);
else if (Op2Set)
// orc(x, 1) = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Unset)
// orc(0, y) = ~y
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(1));
else if (Op1Not)
// orc(~x, y) = ~(x & y) = nand(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRNAND, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(1));
else if (Op2Not)
// orc(x, ~y) = x | y
ResNode = CurDAG->getMachineNode(PPC::CROR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1).
getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(0));
SelectSwap = true;
}
break;
case PPC::SELECT_I4:
case PPC::SELECT_I8:
case PPC::SELECT_F4:
case PPC::SELECT_F8:
case PPC::SELECT_QFRC:
case PPC::SELECT_QSRC:
case PPC::SELECT_QBRC:
case PPC::SELECT_SPE:
case PPC::SELECT_SPE4:
case PPC::SELECT_VRRC:
case PPC::SELECT_VSFRC:
case PPC::SELECT_VSSRC:
case PPC::SELECT_VSRC:
if (Op1Set)
ResNode = MachineNode->getOperand(1).getNode();
else if (Op1Unset)
ResNode = MachineNode->getOperand(2).getNode();
else if (Op1Not)
ResNode = CurDAG->getMachineNode(MachineNode->getMachineOpcode(),
SDLoc(MachineNode),
MachineNode->getValueType(0),
MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(2),
MachineNode->getOperand(1));
break;
case PPC::BC:
case PPC::BCn:
if (Op1Not)
ResNode = CurDAG->getMachineNode(Opcode == PPC::BC ? PPC::BCn :
PPC::BC,
SDLoc(MachineNode),
MVT::Other,
MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(1),
MachineNode->getOperand(2));
// FIXME: Handle Op1Set, Op1Unset here too.
break;
}
// If we're inverting this node because it is used only by selects that
// we'd like to swap, then swap the selects before the node replacement.
if (SelectSwap)
SwapAllSelectUsers(MachineNode);
if (ResNode != MachineNode) {
LLVM_DEBUG(dbgs() << "CR Peephole replacing:\nOld: ");
LLVM_DEBUG(MachineNode->dump(CurDAG));
LLVM_DEBUG(dbgs() << "\nNew: ");
LLVM_DEBUG(ResNode->dump(CurDAG));
LLVM_DEBUG(dbgs() << "\n");
ReplaceUses(MachineNode, ResNode);
IsModified = true;
}
}
if (IsModified)
CurDAG->RemoveDeadNodes();
} while (IsModified);
}
// Gather the set of 32-bit operations that are known to have their
// higher-order 32 bits zero, where ToPromote contains all such operations.
static bool PeepholePPC64ZExtGather(SDValue Op32,
SmallPtrSetImpl<SDNode *> &ToPromote) {
if (!Op32.isMachineOpcode())
return false;
// First, check for the "frontier" instructions (those that will clear the
// higher-order 32 bits.
// For RLWINM and RLWNM, we need to make sure that the mask does not wrap
// around. If it does not, then these instructions will clear the
// higher-order bits.
if ((Op32.getMachineOpcode() == PPC::RLWINM ||
Op32.getMachineOpcode() == PPC::RLWNM) &&
Op32.getConstantOperandVal(2) <= Op32.getConstantOperandVal(3)) {
ToPromote.insert(Op32.getNode());
return true;
}
// SLW and SRW always clear the higher-order bits.
if (Op32.getMachineOpcode() == PPC::SLW ||
Op32.getMachineOpcode() == PPC::SRW) {
ToPromote.insert(Op32.getNode());
return true;
}
// For LI and LIS, we need the immediate to be positive (so that it is not
// sign extended).
if (Op32.getMachineOpcode() == PPC::LI ||
Op32.getMachineOpcode() == PPC::LIS) {
if (!isUInt<15>(Op32.getConstantOperandVal(0)))
return false;
ToPromote.insert(Op32.getNode());
return true;
}
// LHBRX and LWBRX always clear the higher-order bits.
if (Op32.getMachineOpcode() == PPC::LHBRX ||
Op32.getMachineOpcode() == PPC::LWBRX) {
ToPromote.insert(Op32.getNode());
return true;
}
// CNT[LT]ZW always produce a 64-bit value in [0,32], and so is zero extended.
if (Op32.getMachineOpcode() == PPC::CNTLZW ||
Op32.getMachineOpcode() == PPC::CNTTZW) {
ToPromote.insert(Op32.getNode());
return true;
}
// Next, check for those instructions we can look through.
// Assuming the mask does not wrap around, then the higher-order bits are
// taken directly from the first operand.
if (Op32.getMachineOpcode() == PPC::RLWIMI &&
Op32.getConstantOperandVal(3) <= Op32.getConstantOperandVal(4)) {
SmallPtrSet<SDNode *, 16> ToPromote1;
if (!PeepholePPC64ZExtGather(Op32.getOperand(0), ToPromote1))
return false;
ToPromote.insert(Op32.getNode());
ToPromote.insert(ToPromote1.begin(), ToPromote1.end());
return true;
}
// For OR, the higher-order bits are zero if that is true for both operands.
// For SELECT_I4, the same is true (but the relevant operand numbers are
// shifted by 1).
if (Op32.getMachineOpcode() == PPC::OR ||
Op32.getMachineOpcode() == PPC::SELECT_I4) {
unsigned B = Op32.getMachineOpcode() == PPC::SELECT_I4 ? 1 : 0;
SmallPtrSet<SDNode *, 16> ToPromote1;
if (!PeepholePPC64ZExtGather(Op32.getOperand(B+0), ToPromote1))
return false;
if (!PeepholePPC64ZExtGather(Op32.getOperand(B+1), ToPromote1))
return false;
ToPromote.insert(Op32.getNode());
ToPromote.insert(ToPromote1.begin(), ToPromote1.end());
return true;
}
// For ORI and ORIS, we need the higher-order bits of the first operand to be
// zero, and also for the constant to be positive (so that it is not sign
// extended).
if (Op32.getMachineOpcode() == PPC::ORI ||
Op32.getMachineOpcode() == PPC::ORIS) {
SmallPtrSet<SDNode *, 16> ToPromote1;
if (!PeepholePPC64ZExtGather(Op32.getOperand(0), ToPromote1))
return false;
if (!isUInt<15>(Op32.getConstantOperandVal(1)))
return false;
ToPromote.insert(Op32.getNode());
ToPromote.insert(ToPromote1.begin(), ToPromote1.end());
return true;
}
// The higher-order bits of AND are zero if that is true for at least one of
// the operands.
if (Op32.getMachineOpcode() == PPC::AND) {
SmallPtrSet<SDNode *, 16> ToPromote1, ToPromote2;
bool Op0OK =
PeepholePPC64ZExtGather(Op32.getOperand(0), ToPromote1);
bool Op1OK =
PeepholePPC64ZExtGather(Op32.getOperand(1), ToPromote2);
if (!Op0OK && !Op1OK)
return false;
ToPromote.insert(Op32.getNode());
if (Op0OK)
ToPromote.insert(ToPromote1.begin(), ToPromote1.end());
if (Op1OK)
ToPromote.insert(ToPromote2.begin(), ToPromote2.end());
return true;
}
// For ANDI and ANDIS, the higher-order bits are zero if either that is true
// of the first operand, or if the second operand is positive (so that it is
// not sign extended).
if (Op32.getMachineOpcode() == PPC::ANDIo ||
Op32.getMachineOpcode() == PPC::ANDISo) {
SmallPtrSet<SDNode *, 16> ToPromote1;
bool Op0OK =
PeepholePPC64ZExtGather(Op32.getOperand(0), ToPromote1);
bool Op1OK = isUInt<15>(Op32.getConstantOperandVal(1));
if (!Op0OK && !Op1OK)
return false;
ToPromote.insert(Op32.getNode());
if (Op0OK)
ToPromote.insert(ToPromote1.begin(), ToPromote1.end());
return true;
}
return false;
}
void PPCDAGToDAGISel::PeepholePPC64ZExt() {
if (!PPCSubTarget->isPPC64())
return;
// When we zero-extend from i32 to i64, we use a pattern like this:
// def : Pat<(i64 (zext i32:$in)),
// (RLDICL (INSERT_SUBREG (i64 (IMPLICIT_DEF)), $in, sub_32),
// 0, 32)>;
// There are several 32-bit shift/rotate instructions, however, that will
// clear the higher-order bits of their output, rendering the RLDICL
// unnecessary. When that happens, we remove it here, and redefine the
// relevant 32-bit operation to be a 64-bit operation.
SelectionDAG::allnodes_iterator Position = CurDAG->allnodes_end();
bool MadeChange = false;
while (Position != CurDAG->allnodes_begin()) {
SDNode *N = &*--Position;
// Skip dead nodes and any non-machine opcodes.
if (N->use_empty() || !N->isMachineOpcode())
continue;
if (N->getMachineOpcode() != PPC::RLDICL)
continue;
if (N->getConstantOperandVal(1) != 0 ||
N->getConstantOperandVal(2) != 32)
continue;
SDValue ISR = N->getOperand(0);
if (!ISR.isMachineOpcode() ||
ISR.getMachineOpcode() != TargetOpcode::INSERT_SUBREG)
continue;
if (!ISR.hasOneUse())
continue;
if (ISR.getConstantOperandVal(2) != PPC::sub_32)
continue;
SDValue IDef = ISR.getOperand(0);
if (!IDef.isMachineOpcode() ||
IDef.getMachineOpcode() != TargetOpcode::IMPLICIT_DEF)
continue;
// We now know that we're looking at a canonical i32 -> i64 zext. See if we
// can get rid of it.
SDValue Op32 = ISR->getOperand(1);
if (!Op32.isMachineOpcode())
continue;
// There are some 32-bit instructions that always clear the high-order 32
// bits, there are also some instructions (like AND) that we can look
// through.
SmallPtrSet<SDNode *, 16> ToPromote;
if (!PeepholePPC64ZExtGather(Op32, ToPromote))
continue;
// If the ToPromote set contains nodes that have uses outside of the set
// (except for the original INSERT_SUBREG), then abort the transformation.
bool OutsideUse = false;
for (SDNode *PN : ToPromote) {
for (SDNode *UN : PN->uses()) {
if (!ToPromote.count(UN) && UN != ISR.getNode()) {
OutsideUse = true;
break;
}
}
if (OutsideUse)
break;
}
if (OutsideUse)
continue;
MadeChange = true;
// We now know that this zero extension can be removed by promoting to
// nodes in ToPromote to 64-bit operations, where for operations in the
// frontier of the set, we need to insert INSERT_SUBREGs for their
// operands.
for (SDNode *PN : ToPromote) {
unsigned NewOpcode;
switch (PN->getMachineOpcode()) {
default:
llvm_unreachable("Don't know the 64-bit variant of this instruction");
case PPC::RLWINM: NewOpcode = PPC::RLWINM8; break;
case PPC::RLWNM: NewOpcode = PPC::RLWNM8; break;
case PPC::SLW: NewOpcode = PPC::SLW8; break;
case PPC::SRW: NewOpcode = PPC::SRW8; break;
case PPC::LI: NewOpcode = PPC::LI8; break;
case PPC::LIS: NewOpcode = PPC::LIS8; break;
case PPC::LHBRX: NewOpcode = PPC::LHBRX8; break;
case PPC::LWBRX: NewOpcode = PPC::LWBRX8; break;
case PPC::CNTLZW: NewOpcode = PPC::CNTLZW8; break;
case PPC::CNTTZW: NewOpcode = PPC::CNTTZW8; break;
case PPC::RLWIMI: NewOpcode = PPC::RLWIMI8; break;
case PPC::OR: NewOpcode = PPC::OR8; break;
case PPC::SELECT_I4: NewOpcode = PPC::SELECT_I8; break;
case PPC::ORI: NewOpcode = PPC::ORI8; break;
case PPC::ORIS: NewOpcode = PPC::ORIS8; break;
case PPC::AND: NewOpcode = PPC::AND8; break;
case PPC::ANDIo: NewOpcode = PPC::ANDIo8; break;
case PPC::ANDISo: NewOpcode = PPC::ANDISo8; break;
}
// Note: During the replacement process, the nodes will be in an
// inconsistent state (some instructions will have operands with values
// of the wrong type). Once done, however, everything should be right
// again.
SmallVector<SDValue, 4> Ops;
for (const SDValue &V : PN->ops()) {
if (!ToPromote.count(V.getNode()) && V.getValueType() == MVT::i32 &&
!isa<ConstantSDNode>(V)) {
SDValue ReplOpOps[] = { ISR.getOperand(0), V, ISR.getOperand(2) };
SDNode *ReplOp =
CurDAG->getMachineNode(TargetOpcode::INSERT_SUBREG, SDLoc(V),
ISR.getNode()->getVTList(), ReplOpOps);
Ops.push_back(SDValue(ReplOp, 0));
} else {
Ops.push_back(V);
}
}
// Because all to-be-promoted nodes only have users that are other
// promoted nodes (or the original INSERT_SUBREG), we can safely replace
// the i32 result value type with i64.
SmallVector<EVT, 2> NewVTs;
SDVTList VTs = PN->getVTList();
for (unsigned i = 0, ie = VTs.NumVTs; i != ie; ++i)
if (VTs.VTs[i] == MVT::i32)
NewVTs.push_back(MVT::i64);
else
NewVTs.push_back(VTs.VTs[i]);
LLVM_DEBUG(dbgs() << "PPC64 ZExt Peephole morphing:\nOld: ");
LLVM_DEBUG(PN->dump(CurDAG));
CurDAG->SelectNodeTo(PN, NewOpcode, CurDAG->getVTList(NewVTs), Ops);
LLVM_DEBUG(dbgs() << "\nNew: ");
LLVM_DEBUG(PN->dump(CurDAG));
LLVM_DEBUG(dbgs() << "\n");
}
// Now we replace the original zero extend and its associated INSERT_SUBREG
// with the value feeding the INSERT_SUBREG (which has now been promoted to
// return an i64).
LLVM_DEBUG(dbgs() << "PPC64 ZExt Peephole replacing:\nOld: ");
LLVM_DEBUG(N->dump(CurDAG));
LLVM_DEBUG(dbgs() << "\nNew: ");
LLVM_DEBUG(Op32.getNode()->dump(CurDAG));
LLVM_DEBUG(dbgs() << "\n");
ReplaceUses(N, Op32.getNode());
}
if (MadeChange)
CurDAG->RemoveDeadNodes();
}
void PPCDAGToDAGISel::PeepholePPC64() {
// These optimizations are currently supported only for 64-bit SVR4.
if (PPCSubTarget->isDarwin() || !PPCSubTarget->isPPC64())
return;
SelectionDAG::allnodes_iterator Position = CurDAG->allnodes_end();
while (Position != CurDAG->allnodes_begin()) {
SDNode *N = &*--Position;
// Skip dead nodes and any non-machine opcodes.
if (N->use_empty() || !N->isMachineOpcode())
continue;
unsigned FirstOp;
unsigned StorageOpcode = N->getMachineOpcode();
bool RequiresMod4Offset = false;
switch (StorageOpcode) {
default: continue;
case PPC::LWA:
case PPC::LD:
case PPC::DFLOADf64:
case PPC::DFLOADf32:
RequiresMod4Offset = true;
LLVM_FALLTHROUGH;
case PPC::LBZ:
case PPC::LBZ8:
case PPC::LFD:
case PPC::LFS:
case PPC::LHA:
case PPC::LHA8:
case PPC::LHZ:
case PPC::LHZ8:
case PPC::LWZ:
case PPC::LWZ8:
FirstOp = 0;
break;
case PPC::STD:
case PPC::DFSTOREf64:
case PPC::DFSTOREf32:
RequiresMod4Offset = true;
LLVM_FALLTHROUGH;
case PPC::STB:
case PPC::STB8:
case PPC::STFD:
case PPC::STFS:
case PPC::STH:
case PPC::STH8:
case PPC::STW:
case PPC::STW8:
FirstOp = 1;
break;
}
// If this is a load or store with a zero offset, or within the alignment,
// we may be able to fold an add-immediate into the memory operation.
// The check against alignment is below, as it can't occur until we check
// the arguments to N
if (!isa<ConstantSDNode>(N->getOperand(FirstOp)))
continue;
SDValue Base = N->getOperand(FirstOp + 1);
if (!Base.isMachineOpcode())
continue;
unsigned Flags = 0;
bool ReplaceFlags = true;
// When the feeding operation is an add-immediate of some sort,
// determine whether we need to add relocation information to the
// target flags on the immediate operand when we fold it into the
// load instruction.
//
// For something like ADDItocL, the relocation information is
// inferred from the opcode; when we process it in the AsmPrinter,
// we add the necessary relocation there. A load, though, can receive
// relocation from various flavors of ADDIxxx, so we need to carry
// the relocation information in the target flags.
switch (Base.getMachineOpcode()) {
default: continue;
case PPC::ADDI8:
case PPC::ADDI:
// In some cases (such as TLS) the relocation information
// is already in place on the operand, so copying the operand
// is sufficient.
ReplaceFlags = false;
// For these cases, the immediate may not be divisible by 4, in
// which case the fold is illegal for DS-form instructions. (The
// other cases provide aligned addresses and are always safe.)
if (RequiresMod4Offset &&
(!isa<ConstantSDNode>(Base.getOperand(1)) ||
Base.getConstantOperandVal(1) % 4 != 0))
continue;
break;
case PPC::ADDIdtprelL:
Flags = PPCII::MO_DTPREL_LO;
break;
case PPC::ADDItlsldL:
Flags = PPCII::MO_TLSLD_LO;
break;
case PPC::ADDItocL:
Flags = PPCII::MO_TOC_LO;
break;
}
SDValue ImmOpnd = Base.getOperand(1);
// On PPC64, the TOC base pointer is guaranteed by the ABI only to have
// 8-byte alignment, and so we can only use offsets less than 8 (otherwise,
// we might have needed different @ha relocation values for the offset
// pointers).
int MaxDisplacement = 7;
if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(ImmOpnd)) {
const GlobalValue *GV = GA->getGlobal();
MaxDisplacement = std::min((int) GV->getAlignment() - 1, MaxDisplacement);
}
bool UpdateHBase = false;
SDValue HBase = Base.getOperand(0);
int Offset = N->getConstantOperandVal(FirstOp);
if (ReplaceFlags) {
if (Offset < 0 || Offset > MaxDisplacement) {
// If we have a addi(toc@l)/addis(toc@ha) pair, and the addis has only
// one use, then we can do this for any offset, we just need to also
// update the offset (i.e. the symbol addend) on the addis also.
if (Base.getMachineOpcode() != PPC::ADDItocL)
continue;
if (!HBase.isMachineOpcode() ||
HBase.getMachineOpcode() != PPC::ADDIStocHA8)
continue;
if (!Base.hasOneUse() || !HBase.hasOneUse())
continue;
SDValue HImmOpnd = HBase.getOperand(1);
if (HImmOpnd != ImmOpnd)
continue;
UpdateHBase = true;
}
} else {
// If we're directly folding the addend from an addi instruction, then:
// 1. In general, the offset on the memory access must be zero.
// 2. If the addend is a constant, then it can be combined with a
// non-zero offset, but only if the result meets the encoding
// requirements.
if (auto *C = dyn_cast<ConstantSDNode>(ImmOpnd)) {
Offset += C->getSExtValue();
if (RequiresMod4Offset && (Offset % 4) != 0)
continue;
if (!isInt<16>(Offset))
continue;
ImmOpnd = CurDAG->getTargetConstant(Offset, SDLoc(ImmOpnd),
ImmOpnd.getValueType());
} else if (Offset != 0) {
continue;
}
}
// We found an opportunity. Reverse the operands from the add
// immediate and substitute them into the load or store. If
// needed, update the target flags for the immediate operand to
// reflect the necessary relocation information.
LLVM_DEBUG(dbgs() << "Folding add-immediate into mem-op:\nBase: ");
LLVM_DEBUG(Base->dump(CurDAG));
LLVM_DEBUG(dbgs() << "\nN: ");
LLVM_DEBUG(N->dump(CurDAG));
LLVM_DEBUG(dbgs() << "\n");
// If the relocation information isn't already present on the
// immediate operand, add it now.
if (ReplaceFlags) {
if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(ImmOpnd)) {
SDLoc dl(GA);
const GlobalValue *GV = GA->getGlobal();
// We can't perform this optimization for data whose alignment
// is insufficient for the instruction encoding.
if (GV->getAlignment() < 4 &&
(RequiresMod4Offset || (Offset % 4) != 0)) {
LLVM_DEBUG(dbgs() << "Rejected this candidate for alignment.\n\n");
continue;
}
ImmOpnd = CurDAG->getTargetGlobalAddress(GV, dl, MVT::i64, Offset, Flags);
} else if (ConstantPoolSDNode *CP =
dyn_cast<ConstantPoolSDNode>(ImmOpnd)) {
const Constant *C = CP->getConstVal();
ImmOpnd = CurDAG->getTargetConstantPool(C, MVT::i64,
CP->getAlignment(),
Offset, Flags);
}
}
if (FirstOp == 1) // Store
(void)CurDAG->UpdateNodeOperands(N, N->getOperand(0), ImmOpnd,
Base.getOperand(0), N->getOperand(3));
else // Load
(void)CurDAG->UpdateNodeOperands(N, ImmOpnd, Base.getOperand(0),
N->getOperand(2));
if (UpdateHBase)
(void)CurDAG->UpdateNodeOperands(HBase.getNode(), HBase.getOperand(0),
ImmOpnd);
// The add-immediate may now be dead, in which case remove it.
if (Base.getNode()->use_empty())
CurDAG->RemoveDeadNode(Base.getNode());
}
}
/// createPPCISelDag - This pass converts a legalized DAG into a
/// PowerPC-specific DAG, ready for instruction scheduling.
///
FunctionPass *llvm::createPPCISelDag(PPCTargetMachine &TM,
CodeGenOpt::Level OptLevel) {
return new PPCDAGToDAGISel(TM, OptLevel);
}
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