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

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//===-- PPCFastISel.cpp - PowerPC FastISel implementation -----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the PowerPC-specific support for the FastISel class. Some
// of the target-specific code is generated by tablegen in the file
// PPCGenFastISel.inc, which is #included here.
//
//===----------------------------------------------------------------------===//
#include "PPC.h"
#include "MCTargetDesc/PPCPredicates.h"
#include "PPCCallingConv.h"
#include "PPCCCState.h"
#include "PPCISelLowering.h"
#include "PPCMachineFunctionInfo.h"
#include "PPCSubtarget.h"
#include "PPCTargetMachine.h"
#include "llvm/ADT/Optional.h"
#include "llvm/CodeGen/CallingConvLower.h"
#include "llvm/CodeGen/FastISel.h"
#include "llvm/CodeGen/FunctionLoweringInfo.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Operator.h"
#include "llvm/Support/Debug.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetMachine.h"
//===----------------------------------------------------------------------===//
//
// TBD:
// fastLowerArguments: Handle simple cases.
// PPCMaterializeGV: Handle TLS.
// SelectCall: Handle function pointers.
// SelectCall: Handle multi-register return values.
// SelectCall: Optimize away nops for local calls.
// processCallArgs: Handle bit-converted arguments.
// finishCall: Handle multi-register return values.
// PPCComputeAddress: Handle parameter references as FrameIndex's.
// PPCEmitCmp: Handle immediate as operand 1.
// SelectCall: Handle small byval arguments.
// SelectIntrinsicCall: Implement.
// SelectSelect: Implement.
// Consider factoring isTypeLegal into the base class.
// Implement switches and jump tables.
//
//===----------------------------------------------------------------------===//
using namespace llvm;
#define DEBUG_TYPE "ppcfastisel"
namespace {
typedef struct Address {
enum {
RegBase,
FrameIndexBase
} BaseType;
union {
unsigned Reg;
int FI;
} Base;
long Offset;
// Innocuous defaults for our address.
Address()
: BaseType(RegBase), Offset(0) {
Base.Reg = 0;
}
} Address;
class PPCFastISel final : public FastISel {
const TargetMachine &TM;
const PPCSubtarget *PPCSubTarget;
PPCFunctionInfo *PPCFuncInfo;
const TargetInstrInfo &TII;
const TargetLowering &TLI;
LLVMContext *Context;
public:
explicit PPCFastISel(FunctionLoweringInfo &FuncInfo,
const TargetLibraryInfo *LibInfo)
: FastISel(FuncInfo, LibInfo), TM(FuncInfo.MF->getTarget()),
PPCSubTarget(&FuncInfo.MF->getSubtarget<PPCSubtarget>()),
PPCFuncInfo(FuncInfo.MF->getInfo<PPCFunctionInfo>()),
TII(*PPCSubTarget->getInstrInfo()),
TLI(*PPCSubTarget->getTargetLowering()),
Context(&FuncInfo.Fn->getContext()) {}
// Backend specific FastISel code.
private:
bool fastSelectInstruction(const Instruction *I) override;
unsigned fastMaterializeConstant(const Constant *C) override;
unsigned fastMaterializeAlloca(const AllocaInst *AI) override;
bool tryToFoldLoadIntoMI(MachineInstr *MI, unsigned OpNo,
const LoadInst *LI) override;
bool fastLowerArguments() override;
unsigned fastEmit_i(MVT Ty, MVT RetTy, unsigned Opc, uint64_t Imm) override;
unsigned fastEmitInst_ri(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
uint64_t Imm);
unsigned fastEmitInst_r(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill);
unsigned fastEmitInst_rr(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
unsigned Op1, bool Op1IsKill);
bool fastLowerCall(CallLoweringInfo &CLI) override;
// Instruction selection routines.
private:
bool SelectLoad(const Instruction *I);
bool SelectStore(const Instruction *I);
bool SelectBranch(const Instruction *I);
bool SelectIndirectBr(const Instruction *I);
bool SelectFPExt(const Instruction *I);
bool SelectFPTrunc(const Instruction *I);
bool SelectIToFP(const Instruction *I, bool IsSigned);
bool SelectFPToI(const Instruction *I, bool IsSigned);
bool SelectBinaryIntOp(const Instruction *I, unsigned ISDOpcode);
bool SelectRet(const Instruction *I);
bool SelectTrunc(const Instruction *I);
bool SelectIntExt(const Instruction *I);
// Utility routines.
private:
bool isTypeLegal(Type *Ty, MVT &VT);
bool isLoadTypeLegal(Type *Ty, MVT &VT);
bool isValueAvailable(const Value *V) const;
bool isVSFRCRegClass(const TargetRegisterClass *RC) const {
return RC->getID() == PPC::VSFRCRegClassID;
}
bool isVSSRCRegClass(const TargetRegisterClass *RC) const {
return RC->getID() == PPC::VSSRCRegClassID;
}
bool PPCEmitCmp(const Value *Src1Value, const Value *Src2Value,
bool isZExt, unsigned DestReg);
bool PPCEmitLoad(MVT VT, unsigned &ResultReg, Address &Addr,
const TargetRegisterClass *RC, bool IsZExt = true,
unsigned FP64LoadOpc = PPC::LFD);
bool PPCEmitStore(MVT VT, unsigned SrcReg, Address &Addr);
bool PPCComputeAddress(const Value *Obj, Address &Addr);
void PPCSimplifyAddress(Address &Addr, bool &UseOffset,
unsigned &IndexReg);
bool PPCEmitIntExt(MVT SrcVT, unsigned SrcReg, MVT DestVT,
unsigned DestReg, bool IsZExt);
unsigned PPCMaterializeFP(const ConstantFP *CFP, MVT VT);
unsigned PPCMaterializeGV(const GlobalValue *GV, MVT VT);
unsigned PPCMaterializeInt(const ConstantInt *CI, MVT VT,
bool UseSExt = true);
unsigned PPCMaterialize32BitInt(int64_t Imm,
const TargetRegisterClass *RC);
unsigned PPCMaterialize64BitInt(int64_t Imm,
const TargetRegisterClass *RC);
unsigned PPCMoveToIntReg(const Instruction *I, MVT VT,
unsigned SrcReg, bool IsSigned);
unsigned PPCMoveToFPReg(MVT VT, unsigned SrcReg, bool IsSigned);
// Call handling routines.
private:
bool processCallArgs(SmallVectorImpl<Value*> &Args,
SmallVectorImpl<unsigned> &ArgRegs,
SmallVectorImpl<MVT> &ArgVTs,
SmallVectorImpl<ISD::ArgFlagsTy> &ArgFlags,
SmallVectorImpl<unsigned> &RegArgs,
CallingConv::ID CC,
unsigned &NumBytes,
bool IsVarArg);
bool finishCall(MVT RetVT, CallLoweringInfo &CLI, unsigned &NumBytes);
LLVM_ATTRIBUTE_UNUSED CCAssignFn *usePPC32CCs(unsigned Flag);
private:
#include "PPCGenFastISel.inc"
};
} // end anonymous namespace
#include "PPCGenCallingConv.inc"
// Function whose sole purpose is to kill compiler warnings
// stemming from unused functions included from PPCGenCallingConv.inc.
CCAssignFn *PPCFastISel::usePPC32CCs(unsigned Flag) {
if (Flag == 1)
return CC_PPC32_SVR4;
else if (Flag == 2)
return CC_PPC32_SVR4_ByVal;
else if (Flag == 3)
return CC_PPC32_SVR4_VarArg;
else
return RetCC_PPC;
}
static Optional<PPC::Predicate> getComparePred(CmpInst::Predicate Pred) {
switch (Pred) {
// These are not representable with any single compare.
case CmpInst::FCMP_FALSE:
case CmpInst::FCMP_TRUE:
// Major concern about the following 6 cases is NaN result. The comparison
// result consists of 4 bits, indicating lt, eq, gt and un (unordered),
// only one of which will be set. The result is generated by fcmpu
// instruction. However, bc instruction only inspects one of the first 3
// bits, so when un is set, bc instruction may jump to to an undesired
// place.
//
// More specifically, if we expect an unordered comparison and un is set, we
// expect to always go to true branch; in such case UEQ, UGT and ULT still
// give false, which are undesired; but UNE, UGE, ULE happen to give true,
// since they are tested by inspecting !eq, !lt, !gt, respectively.
//
// Similarly, for ordered comparison, when un is set, we always expect the
// result to be false. In such case OGT, OLT and OEQ is good, since they are
// actually testing GT, LT, and EQ respectively, which are false. OGE, OLE
// and ONE are tested through !lt, !gt and !eq, and these are true.
case CmpInst::FCMP_UEQ:
case CmpInst::FCMP_UGT:
case CmpInst::FCMP_ULT:
case CmpInst::FCMP_OGE:
case CmpInst::FCMP_OLE:
case CmpInst::FCMP_ONE:
default:
return Optional<PPC::Predicate>();
case CmpInst::FCMP_OEQ:
case CmpInst::ICMP_EQ:
return PPC::PRED_EQ;
case CmpInst::FCMP_OGT:
case CmpInst::ICMP_UGT:
case CmpInst::ICMP_SGT:
return PPC::PRED_GT;
case CmpInst::FCMP_UGE:
case CmpInst::ICMP_UGE:
case CmpInst::ICMP_SGE:
return PPC::PRED_GE;
case CmpInst::FCMP_OLT:
case CmpInst::ICMP_ULT:
case CmpInst::ICMP_SLT:
return PPC::PRED_LT;
case CmpInst::FCMP_ULE:
case CmpInst::ICMP_ULE:
case CmpInst::ICMP_SLE:
return PPC::PRED_LE;
case CmpInst::FCMP_UNE:
case CmpInst::ICMP_NE:
return PPC::PRED_NE;
case CmpInst::FCMP_ORD:
return PPC::PRED_NU;
case CmpInst::FCMP_UNO:
return PPC::PRED_UN;
}
}
// Determine whether the type Ty is simple enough to be handled by
// fast-isel, and return its equivalent machine type in VT.
// FIXME: Copied directly from ARM -- factor into base class?
bool PPCFastISel::isTypeLegal(Type *Ty, MVT &VT) {
EVT Evt = TLI.getValueType(DL, Ty, true);
// Only handle simple types.
if (Evt == MVT::Other || !Evt.isSimple()) return false;
VT = Evt.getSimpleVT();
// Handle all legal types, i.e. a register that will directly hold this
// value.
return TLI.isTypeLegal(VT);
}
// Determine whether the type Ty is simple enough to be handled by
// fast-isel as a load target, and return its equivalent machine type in VT.
bool PPCFastISel::isLoadTypeLegal(Type *Ty, MVT &VT) {
if (isTypeLegal(Ty, VT)) return true;
// If this is a type than can be sign or zero-extended to a basic operation
// go ahead and accept it now.
if (VT == MVT::i8 || VT == MVT::i16 || VT == MVT::i32) {
return true;
}
return false;
}
bool PPCFastISel::isValueAvailable(const Value *V) const {
if (!isa<Instruction>(V))
return true;
const auto *I = cast<Instruction>(V);
return FuncInfo.MBBMap[I->getParent()] == FuncInfo.MBB;
}
// Given a value Obj, create an Address object Addr that represents its
// address. Return false if we can't handle it.
bool PPCFastISel::PPCComputeAddress(const Value *Obj, Address &Addr) {
const User *U = nullptr;
unsigned Opcode = Instruction::UserOp1;
if (const Instruction *I = dyn_cast<Instruction>(Obj)) {
// Don't walk into other basic blocks unless the object is an alloca from
// another block, otherwise it may not have a virtual register assigned.
if (FuncInfo.StaticAllocaMap.count(static_cast<const AllocaInst *>(Obj)) ||
FuncInfo.MBBMap[I->getParent()] == FuncInfo.MBB) {
Opcode = I->getOpcode();
U = I;
}
} else if (const ConstantExpr *C = dyn_cast<ConstantExpr>(Obj)) {
Opcode = C->getOpcode();
U = C;
}
switch (Opcode) {
default:
break;
case Instruction::BitCast:
// Look through bitcasts.
return PPCComputeAddress(U->getOperand(0), Addr);
case Instruction::IntToPtr:
// Look past no-op inttoptrs.
if (TLI.getValueType(DL, U->getOperand(0)->getType()) ==
TLI.getPointerTy(DL))
return PPCComputeAddress(U->getOperand(0), Addr);
break;
case Instruction::PtrToInt:
// Look past no-op ptrtoints.
if (TLI.getValueType(DL, U->getType()) == TLI.getPointerTy(DL))
return PPCComputeAddress(U->getOperand(0), Addr);
break;
case Instruction::GetElementPtr: {
Address SavedAddr = Addr;
long TmpOffset = Addr.Offset;
// Iterate through the GEP folding the constants into offsets where
// we can.
gep_type_iterator GTI = gep_type_begin(U);
for (User::const_op_iterator II = U->op_begin() + 1, IE = U->op_end();
II != IE; ++II, ++GTI) {
const Value *Op = *II;
if (StructType *STy = GTI.getStructTypeOrNull()) {
const StructLayout *SL = DL.getStructLayout(STy);
unsigned Idx = cast<ConstantInt>(Op)->getZExtValue();
TmpOffset += SL->getElementOffset(Idx);
} else {
uint64_t S = DL.getTypeAllocSize(GTI.getIndexedType());
for (;;) {
if (const ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
// Constant-offset addressing.
TmpOffset += CI->getSExtValue() * S;
break;
}
if (canFoldAddIntoGEP(U, Op)) {
// A compatible add with a constant operand. Fold the constant.
ConstantInt *CI =
cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1));
TmpOffset += CI->getSExtValue() * S;
// Iterate on the other operand.
Op = cast<AddOperator>(Op)->getOperand(0);
continue;
}
// Unsupported
goto unsupported_gep;
}
}
}
// Try to grab the base operand now.
Addr.Offset = TmpOffset;
if (PPCComputeAddress(U->getOperand(0), Addr)) return true;
// We failed, restore everything and try the other options.
Addr = SavedAddr;
unsupported_gep:
break;
}
case Instruction::Alloca: {
const AllocaInst *AI = cast<AllocaInst>(Obj);
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI != FuncInfo.StaticAllocaMap.end()) {
Addr.BaseType = Address::FrameIndexBase;
Addr.Base.FI = SI->second;
return true;
}
break;
}
}
// FIXME: References to parameters fall through to the behavior
// below. They should be able to reference a frame index since
// they are stored to the stack, so we can get "ld rx, offset(r1)"
// instead of "addi ry, r1, offset / ld rx, 0(ry)". Obj will
// just contain the parameter. Try to handle this with a FI.
// Try to get this in a register if nothing else has worked.
if (Addr.Base.Reg == 0)
Addr.Base.Reg = getRegForValue(Obj);
// Prevent assignment of base register to X0, which is inappropriate
// for loads and stores alike.
if (Addr.Base.Reg != 0)
MRI.setRegClass(Addr.Base.Reg, &PPC::G8RC_and_G8RC_NOX0RegClass);
return Addr.Base.Reg != 0;
}
// Fix up some addresses that can't be used directly. For example, if
// an offset won't fit in an instruction field, we may need to move it
// into an index register.
void PPCFastISel::PPCSimplifyAddress(Address &Addr, bool &UseOffset,
unsigned &IndexReg) {
// Check whether the offset fits in the instruction field.
if (!isInt<16>(Addr.Offset))
UseOffset = false;
// If this is a stack pointer and the offset needs to be simplified then
// put the alloca address into a register, set the base type back to
// register and continue. This should almost never happen.
if (!UseOffset && Addr.BaseType == Address::FrameIndexBase) {
unsigned ResultReg = createResultReg(&PPC::G8RC_and_G8RC_NOX0RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::ADDI8),
ResultReg).addFrameIndex(Addr.Base.FI).addImm(0);
Addr.Base.Reg = ResultReg;
Addr.BaseType = Address::RegBase;
}
if (!UseOffset) {
IntegerType *OffsetTy = Type::getInt64Ty(*Context);
const ConstantInt *Offset =
ConstantInt::getSigned(OffsetTy, (int64_t)(Addr.Offset));
IndexReg = PPCMaterializeInt(Offset, MVT::i64);
assert(IndexReg && "Unexpected error in PPCMaterializeInt!");
}
}
// Emit a load instruction if possible, returning true if we succeeded,
// otherwise false. See commentary below for how the register class of
// the load is determined.
bool PPCFastISel::PPCEmitLoad(MVT VT, unsigned &ResultReg, Address &Addr,
const TargetRegisterClass *RC,
bool IsZExt, unsigned FP64LoadOpc) {
unsigned Opc;
bool UseOffset = true;
// If ResultReg is given, it determines the register class of the load.
// Otherwise, RC is the register class to use. If the result of the
// load isn't anticipated in this block, both may be zero, in which
// case we must make a conservative guess. In particular, don't assign
// R0 or X0 to the result register, as the result may be used in a load,
// store, add-immediate, or isel that won't permit this. (Though
// perhaps the spill and reload of live-exit values would handle this?)
const TargetRegisterClass *UseRC =
(ResultReg ? MRI.getRegClass(ResultReg) :
(RC ? RC :
(VT == MVT::f64 ? &PPC::F8RCRegClass :
(VT == MVT::f32 ? &PPC::F4RCRegClass :
(VT == MVT::i64 ? &PPC::G8RC_and_G8RC_NOX0RegClass :
&PPC::GPRC_and_GPRC_NOR0RegClass)))));
bool Is32BitInt = UseRC->hasSuperClassEq(&PPC::GPRCRegClass);
switch (VT.SimpleTy) {
default: // e.g., vector types not handled
return false;
case MVT::i8:
Opc = Is32BitInt ? PPC::LBZ : PPC::LBZ8;
break;
case MVT::i16:
Opc = (IsZExt ? (Is32BitInt ? PPC::LHZ : PPC::LHZ8)
: (Is32BitInt ? PPC::LHA : PPC::LHA8));
break;
case MVT::i32:
Opc = (IsZExt ? (Is32BitInt ? PPC::LWZ : PPC::LWZ8)
: (Is32BitInt ? PPC::LWA_32 : PPC::LWA));
if ((Opc == PPC::LWA || Opc == PPC::LWA_32) && ((Addr.Offset & 3) != 0))
UseOffset = false;
break;
case MVT::i64:
Opc = PPC::LD;
assert(UseRC->hasSuperClassEq(&PPC::G8RCRegClass) &&
"64-bit load with 32-bit target??");
UseOffset = ((Addr.Offset & 3) == 0);
break;
case MVT::f32:
Opc = PPC::LFS;
break;
case MVT::f64:
Opc = FP64LoadOpc;
break;
}
// If necessary, materialize the offset into a register and use
// the indexed form. Also handle stack pointers with special needs.
unsigned IndexReg = 0;
PPCSimplifyAddress(Addr, UseOffset, IndexReg);
// If this is a potential VSX load with an offset of 0, a VSX indexed load can
// be used.
bool IsVSSRC = isVSSRCRegClass(UseRC);
bool IsVSFRC = isVSFRCRegClass(UseRC);
bool Is32VSXLoad = IsVSSRC && Opc == PPC::LFS;
bool Is64VSXLoad = IsVSFRC && Opc == PPC::LFD;
if ((Is32VSXLoad || Is64VSXLoad) &&
(Addr.BaseType != Address::FrameIndexBase) && UseOffset &&
(Addr.Offset == 0)) {
UseOffset = false;
}
if (ResultReg == 0)
ResultReg = createResultReg(UseRC);
// Note: If we still have a frame index here, we know the offset is
// in range, as otherwise PPCSimplifyAddress would have converted it
// into a RegBase.
if (Addr.BaseType == Address::FrameIndexBase) {
// VSX only provides an indexed load.
if (Is32VSXLoad || Is64VSXLoad) return false;
MachineMemOperand *MMO = FuncInfo.MF->getMachineMemOperand(
MachinePointerInfo::getFixedStack(*FuncInfo.MF, Addr.Base.FI,
Addr.Offset),
MachineMemOperand::MOLoad, MFI.getObjectSize(Addr.Base.FI),
MFI.getObjectAlignment(Addr.Base.FI));
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg)
.addImm(Addr.Offset).addFrameIndex(Addr.Base.FI).addMemOperand(MMO);
// Base reg with offset in range.
} else if (UseOffset) {
// VSX only provides an indexed load.
if (Is32VSXLoad || Is64VSXLoad) return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg)
.addImm(Addr.Offset).addReg(Addr.Base.Reg);
// Indexed form.
} else {
// Get the RR opcode corresponding to the RI one. FIXME: It would be
// preferable to use the ImmToIdxMap from PPCRegisterInfo.cpp, but it
// is hard to get at.
switch (Opc) {
default: llvm_unreachable("Unexpected opcode!");
case PPC::LBZ: Opc = PPC::LBZX; break;
case PPC::LBZ8: Opc = PPC::LBZX8; break;
case PPC::LHZ: Opc = PPC::LHZX; break;
case PPC::LHZ8: Opc = PPC::LHZX8; break;
case PPC::LHA: Opc = PPC::LHAX; break;
case PPC::LHA8: Opc = PPC::LHAX8; break;
case PPC::LWZ: Opc = PPC::LWZX; break;
case PPC::LWZ8: Opc = PPC::LWZX8; break;
case PPC::LWA: Opc = PPC::LWAX; break;
case PPC::LWA_32: Opc = PPC::LWAX_32; break;
case PPC::LD: Opc = PPC::LDX; break;
case PPC::LFS: Opc = IsVSSRC ? PPC::LXSSPX : PPC::LFSX; break;
case PPC::LFD: Opc = IsVSFRC ? PPC::LXSDX : PPC::LFDX; break;
}
auto MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc),
ResultReg);
// If we have an index register defined we use it in the store inst,
// otherwise we use X0 as base as it makes the vector instructions to
// use zero in the computation of the effective address regardless the
// content of the register.
if (IndexReg)
MIB.addReg(Addr.Base.Reg).addReg(IndexReg);
else
MIB.addReg(PPC::ZERO8).addReg(Addr.Base.Reg);
}
return true;
}
// Attempt to fast-select a load instruction.
bool PPCFastISel::SelectLoad(const Instruction *I) {
// FIXME: No atomic loads are supported.
if (cast<LoadInst>(I)->isAtomic())
return false;
// Verify we have a legal type before going any further.
MVT VT;
if (!isLoadTypeLegal(I->getType(), VT))
return false;
// See if we can handle this address.
Address Addr;
if (!PPCComputeAddress(I->getOperand(0), Addr))
return false;
// Look at the currently assigned register for this instruction
// to determine the required register class. This is necessary
// to constrain RA from using R0/X0 when this is not legal.
unsigned AssignedReg = FuncInfo.ValueMap[I];
const TargetRegisterClass *RC =
AssignedReg ? MRI.getRegClass(AssignedReg) : nullptr;
unsigned ResultReg = 0;
if (!PPCEmitLoad(VT, ResultReg, Addr, RC))
return false;
updateValueMap(I, ResultReg);
return true;
}
// Emit a store instruction to store SrcReg at Addr.
bool PPCFastISel::PPCEmitStore(MVT VT, unsigned SrcReg, Address &Addr) {
assert(SrcReg && "Nothing to store!");
unsigned Opc;
bool UseOffset = true;
const TargetRegisterClass *RC = MRI.getRegClass(SrcReg);
bool Is32BitInt = RC->hasSuperClassEq(&PPC::GPRCRegClass);
switch (VT.SimpleTy) {
default: // e.g., vector types not handled
return false;
case MVT::i8:
Opc = Is32BitInt ? PPC::STB : PPC::STB8;
break;
case MVT::i16:
Opc = Is32BitInt ? PPC::STH : PPC::STH8;
break;
case MVT::i32:
assert(Is32BitInt && "Not GPRC for i32??");
Opc = PPC::STW;
break;
case MVT::i64:
Opc = PPC::STD;
UseOffset = ((Addr.Offset & 3) == 0);
break;
case MVT::f32:
Opc = PPC::STFS;
break;
case MVT::f64:
Opc = PPC::STFD;
break;
}
// If necessary, materialize the offset into a register and use
// the indexed form. Also handle stack pointers with special needs.
unsigned IndexReg = 0;
PPCSimplifyAddress(Addr, UseOffset, IndexReg);
// If this is a potential VSX store with an offset of 0, a VSX indexed store
// can be used.
bool IsVSSRC = isVSSRCRegClass(RC);
bool IsVSFRC = isVSFRCRegClass(RC);
bool Is32VSXStore = IsVSSRC && Opc == PPC::STFS;
bool Is64VSXStore = IsVSFRC && Opc == PPC::STFD;
if ((Is32VSXStore || Is64VSXStore) &&
(Addr.BaseType != Address::FrameIndexBase) && UseOffset &&
(Addr.Offset == 0)) {
UseOffset = false;
}
// Note: If we still have a frame index here, we know the offset is
// in range, as otherwise PPCSimplifyAddress would have converted it
// into a RegBase.
if (Addr.BaseType == Address::FrameIndexBase) {
// VSX only provides an indexed store.
if (Is32VSXStore || Is64VSXStore) return false;
MachineMemOperand *MMO = FuncInfo.MF->getMachineMemOperand(
MachinePointerInfo::getFixedStack(*FuncInfo.MF, Addr.Base.FI,
Addr.Offset),
MachineMemOperand::MOStore, MFI.getObjectSize(Addr.Base.FI),
MFI.getObjectAlignment(Addr.Base.FI));
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc))
.addReg(SrcReg)
.addImm(Addr.Offset)
.addFrameIndex(Addr.Base.FI)
.addMemOperand(MMO);
// Base reg with offset in range.
} else if (UseOffset) {
// VSX only provides an indexed store.
if (Is32VSXStore || Is64VSXStore)
return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc))
.addReg(SrcReg).addImm(Addr.Offset).addReg(Addr.Base.Reg);
// Indexed form.
} else {
// Get the RR opcode corresponding to the RI one. FIXME: It would be
// preferable to use the ImmToIdxMap from PPCRegisterInfo.cpp, but it
// is hard to get at.
switch (Opc) {
default: llvm_unreachable("Unexpected opcode!");
case PPC::STB: Opc = PPC::STBX; break;
case PPC::STH : Opc = PPC::STHX; break;
case PPC::STW : Opc = PPC::STWX; break;
case PPC::STB8: Opc = PPC::STBX8; break;
case PPC::STH8: Opc = PPC::STHX8; break;
case PPC::STW8: Opc = PPC::STWX8; break;
case PPC::STD: Opc = PPC::STDX; break;
case PPC::STFS: Opc = IsVSSRC ? PPC::STXSSPX : PPC::STFSX; break;
case PPC::STFD: Opc = IsVSFRC ? PPC::STXSDX : PPC::STFDX; break;
}
auto MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc))
.addReg(SrcReg);
// If we have an index register defined we use it in the store inst,
// otherwise we use X0 as base as it makes the vector instructions to
// use zero in the computation of the effective address regardless the
// content of the register.
if (IndexReg)
MIB.addReg(Addr.Base.Reg).addReg(IndexReg);
else
MIB.addReg(PPC::ZERO8).addReg(Addr.Base.Reg);
}
return true;
}
// Attempt to fast-select a store instruction.
bool PPCFastISel::SelectStore(const Instruction *I) {
Value *Op0 = I->getOperand(0);
unsigned SrcReg = 0;
// FIXME: No atomics loads are supported.
if (cast<StoreInst>(I)->isAtomic())
return false;
// Verify we have a legal type before going any further.
MVT VT;
if (!isLoadTypeLegal(Op0->getType(), VT))
return false;
// Get the value to be stored into a register.
SrcReg = getRegForValue(Op0);
if (SrcReg == 0)
return false;
// See if we can handle this address.
Address Addr;
if (!PPCComputeAddress(I->getOperand(1), Addr))
return false;
if (!PPCEmitStore(VT, SrcReg, Addr))
return false;
return true;
}
// Attempt to fast-select a branch instruction.
bool PPCFastISel::SelectBranch(const Instruction *I) {
const BranchInst *BI = cast<BranchInst>(I);
MachineBasicBlock *BrBB = FuncInfo.MBB;
MachineBasicBlock *TBB = FuncInfo.MBBMap[BI->getSuccessor(0)];
MachineBasicBlock *FBB = FuncInfo.MBBMap[BI->getSuccessor(1)];
// For now, just try the simplest case where it's fed by a compare.
if (const CmpInst *CI = dyn_cast<CmpInst>(BI->getCondition())) {
if (isValueAvailable(CI)) {
Optional<PPC::Predicate> OptPPCPred = getComparePred(CI->getPredicate());
if (!OptPPCPred)
return false;
PPC::Predicate PPCPred = OptPPCPred.getValue();
// Take advantage of fall-through opportunities.
if (FuncInfo.MBB->isLayoutSuccessor(TBB)) {
std::swap(TBB, FBB);
PPCPred = PPC::InvertPredicate(PPCPred);
}
unsigned CondReg = createResultReg(&PPC::CRRCRegClass);
if (!PPCEmitCmp(CI->getOperand(0), CI->getOperand(1), CI->isUnsigned(),
CondReg))
return false;
BuildMI(*BrBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::BCC))
.addImm(PPCPred).addReg(CondReg).addMBB(TBB);
finishCondBranch(BI->getParent(), TBB, FBB);
return true;
}
} else if (const ConstantInt *CI =
dyn_cast<ConstantInt>(BI->getCondition())) {
uint64_t Imm = CI->getZExtValue();
MachineBasicBlock *Target = (Imm == 0) ? FBB : TBB;
fastEmitBranch(Target, DbgLoc);
return true;
}
// FIXME: ARM looks for a case where the block containing the compare
// has been split from the block containing the branch. If this happens,
// there is a vreg available containing the result of the compare. I'm
// not sure we can do much, as we've lost the predicate information with
// the compare instruction -- we have a 4-bit CR but don't know which bit
// to test here.
return false;
}
// Attempt to emit a compare of the two source values. Signed and unsigned
// comparisons are supported. Return false if we can't handle it.
bool PPCFastISel::PPCEmitCmp(const Value *SrcValue1, const Value *SrcValue2,
bool IsZExt, unsigned DestReg) {
Type *Ty = SrcValue1->getType();
EVT SrcEVT = TLI.getValueType(DL, Ty, true);
if (!SrcEVT.isSimple())
return false;
MVT SrcVT = SrcEVT.getSimpleVT();
if (SrcVT == MVT::i1 && PPCSubTarget->useCRBits())
return false;
// See if operand 2 is an immediate encodeable in the compare.
// FIXME: Operands are not in canonical order at -O0, so an immediate
// operand in position 1 is a lost opportunity for now. We are
// similar to ARM in this regard.
long Imm = 0;
bool UseImm = false;
// Only 16-bit integer constants can be represented in compares for
// PowerPC. Others will be materialized into a register.
if (const ConstantInt *ConstInt = dyn_cast<ConstantInt>(SrcValue2)) {
if (SrcVT == MVT::i64 || SrcVT == MVT::i32 || SrcVT == MVT::i16 ||
SrcVT == MVT::i8 || SrcVT == MVT::i1) {
const APInt &CIVal = ConstInt->getValue();
Imm = (IsZExt) ? (long)CIVal.getZExtValue() : (long)CIVal.getSExtValue();
if ((IsZExt && isUInt<16>(Imm)) || (!IsZExt && isInt<16>(Imm)))
UseImm = true;
}
}
unsigned CmpOpc;
bool NeedsExt = false;
switch (SrcVT.SimpleTy) {
default: return false;
case MVT::f32:
CmpOpc = PPC::FCMPUS;
break;
case MVT::f64:
CmpOpc = PPC::FCMPUD;
break;
case MVT::i1:
case MVT::i8:
case MVT::i16:
NeedsExt = true;
// Intentional fall-through.
case MVT::i32:
if (!UseImm)
CmpOpc = IsZExt ? PPC::CMPLW : PPC::CMPW;
else
CmpOpc = IsZExt ? PPC::CMPLWI : PPC::CMPWI;
break;
case MVT::i64:
if (!UseImm)
CmpOpc = IsZExt ? PPC::CMPLD : PPC::CMPD;
else
CmpOpc = IsZExt ? PPC::CMPLDI : PPC::CMPDI;
break;
}
unsigned SrcReg1 = getRegForValue(SrcValue1);
if (SrcReg1 == 0)
return false;
unsigned SrcReg2 = 0;
if (!UseImm) {
SrcReg2 = getRegForValue(SrcValue2);
if (SrcReg2 == 0)
return false;
}
if (NeedsExt) {
unsigned ExtReg = createResultReg(&PPC::GPRCRegClass);
if (!PPCEmitIntExt(SrcVT, SrcReg1, MVT::i32, ExtReg, IsZExt))
return false;
SrcReg1 = ExtReg;
if (!UseImm) {
unsigned ExtReg = createResultReg(&PPC::GPRCRegClass);
if (!PPCEmitIntExt(SrcVT, SrcReg2, MVT::i32, ExtReg, IsZExt))
return false;
SrcReg2 = ExtReg;
}
}
if (!UseImm)
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(CmpOpc), DestReg)
.addReg(SrcReg1).addReg(SrcReg2);
else
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(CmpOpc), DestReg)
.addReg(SrcReg1).addImm(Imm);
return true;
}
// Attempt to fast-select a floating-point extend instruction.
bool PPCFastISel::SelectFPExt(const Instruction *I) {
Value *Src = I->getOperand(0);
EVT SrcVT = TLI.getValueType(DL, Src->getType(), true);
EVT DestVT = TLI.getValueType(DL, I->getType(), true);
if (SrcVT != MVT::f32 || DestVT != MVT::f64)
return false;
unsigned SrcReg = getRegForValue(Src);
if (!SrcReg)
return false;
// No code is generated for a FP extend.
updateValueMap(I, SrcReg);
return true;
}
// Attempt to fast-select a floating-point truncate instruction.
bool PPCFastISel::SelectFPTrunc(const Instruction *I) {
Value *Src = I->getOperand(0);
EVT SrcVT = TLI.getValueType(DL, Src->getType(), true);
EVT DestVT = TLI.getValueType(DL, I->getType(), true);
if (SrcVT != MVT::f64 || DestVT != MVT::f32)
return false;
unsigned SrcReg = getRegForValue(Src);
if (!SrcReg)
return false;
// Round the result to single precision.
unsigned DestReg = createResultReg(&PPC::F4RCRegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::FRSP), DestReg)
.addReg(SrcReg);
updateValueMap(I, DestReg);
return true;
}
// Move an i32 or i64 value in a GPR to an f64 value in an FPR.
// FIXME: When direct register moves are implemented (see PowerISA 2.07),
// those should be used instead of moving via a stack slot when the
// subtarget permits.
// FIXME: The code here is sloppy for the 4-byte case. Can use a 4-byte
// stack slot and 4-byte store/load sequence. Or just sext the 4-byte
// case to 8 bytes which produces tighter code but wastes stack space.
unsigned PPCFastISel::PPCMoveToFPReg(MVT SrcVT, unsigned SrcReg,
bool IsSigned) {
// If necessary, extend 32-bit int to 64-bit.
if (SrcVT == MVT::i32) {
unsigned TmpReg = createResultReg(&PPC::G8RCRegClass);
if (!PPCEmitIntExt(MVT::i32, SrcReg, MVT::i64, TmpReg, !IsSigned))
return 0;
SrcReg = TmpReg;
}
// Get a stack slot 8 bytes wide, aligned on an 8-byte boundary.
Address Addr;
Addr.BaseType = Address::FrameIndexBase;
Addr.Base.FI = MFI.CreateStackObject(8, 8, false);
// Store the value from the GPR.
if (!PPCEmitStore(MVT::i64, SrcReg, Addr))
return 0;
// Load the integer value into an FPR. The kind of load used depends
// on a number of conditions.
unsigned LoadOpc = PPC::LFD;
if (SrcVT == MVT::i32) {
if (!IsSigned) {
LoadOpc = PPC::LFIWZX;
Addr.Offset = (PPCSubTarget->isLittleEndian()) ? 0 : 4;
} else if (PPCSubTarget->hasLFIWAX()) {
LoadOpc = PPC::LFIWAX;
Addr.Offset = (PPCSubTarget->isLittleEndian()) ? 0 : 4;
}
}
const TargetRegisterClass *RC = &PPC::F8RCRegClass;
unsigned ResultReg = 0;
if (!PPCEmitLoad(MVT::f64, ResultReg, Addr, RC, !IsSigned, LoadOpc))
return 0;
return ResultReg;
}
// Attempt to fast-select an integer-to-floating-point conversion.
// FIXME: Once fast-isel has better support for VSX, conversions using
// direct moves should be implemented.
bool PPCFastISel::SelectIToFP(const Instruction *I, bool IsSigned) {
MVT DstVT;
Type *DstTy = I->getType();
if (!isTypeLegal(DstTy, DstVT))
return false;
if (DstVT != MVT::f32 && DstVT != MVT::f64)
return false;
Value *Src = I->getOperand(0);
EVT SrcEVT = TLI.getValueType(DL, Src->getType(), true);
if (!SrcEVT.isSimple())
return false;
MVT SrcVT = SrcEVT.getSimpleVT();
if (SrcVT != MVT::i8 && SrcVT != MVT::i16 &&
SrcVT != MVT::i32 && SrcVT != MVT::i64)
return false;
unsigned SrcReg = getRegForValue(Src);
if (SrcReg == 0)
return false;
// We can only lower an unsigned convert if we have the newer
// floating-point conversion operations.
if (!IsSigned && !PPCSubTarget->hasFPCVT())
return false;
// FIXME: For now we require the newer floating-point conversion operations
// (which are present only on P7 and A2 server models) when converting
// to single-precision float. Otherwise we have to generate a lot of
// fiddly code to avoid double rounding. If necessary, the fiddly code
// can be found in PPCTargetLowering::LowerINT_TO_FP().
if (DstVT == MVT::f32 && !PPCSubTarget->hasFPCVT())
return false;
// Extend the input if necessary.
if (SrcVT == MVT::i8 || SrcVT == MVT::i16) {
unsigned TmpReg = createResultReg(&PPC::G8RCRegClass);
if (!PPCEmitIntExt(SrcVT, SrcReg, MVT::i64, TmpReg, !IsSigned))
return false;
SrcVT = MVT::i64;
SrcReg = TmpReg;
}
// Move the integer value to an FPR.
unsigned FPReg = PPCMoveToFPReg(SrcVT, SrcReg, IsSigned);
if (FPReg == 0)
return false;
// Determine the opcode for the conversion.
const TargetRegisterClass *RC = &PPC::F8RCRegClass;
unsigned DestReg = createResultReg(RC);
unsigned Opc;
if (DstVT == MVT::f32)
Opc = IsSigned ? PPC::FCFIDS : PPC::FCFIDUS;
else
Opc = IsSigned ? PPC::FCFID : PPC::FCFIDU;
// Generate the convert.
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), DestReg)
.addReg(FPReg);
updateValueMap(I, DestReg);
return true;
}
// Move the floating-point value in SrcReg into an integer destination
// register, and return the register (or zero if we can't handle it).
// FIXME: When direct register moves are implemented (see PowerISA 2.07),
// those should be used instead of moving via a stack slot when the
// subtarget permits.
unsigned PPCFastISel::PPCMoveToIntReg(const Instruction *I, MVT VT,
unsigned SrcReg, bool IsSigned) {
// Get a stack slot 8 bytes wide, aligned on an 8-byte boundary.
// Note that if have STFIWX available, we could use a 4-byte stack
// slot for i32, but this being fast-isel we'll just go with the
// easiest code gen possible.
Address Addr;
Addr.BaseType = Address::FrameIndexBase;
Addr.Base.FI = MFI.CreateStackObject(8, 8, false);
// Store the value from the FPR.
if (!PPCEmitStore(MVT::f64, SrcReg, Addr))
return 0;
// Reload it into a GPR. If we want an i32 on big endian, modify the
// address to have a 4-byte offset so we load from the right place.
if (VT == MVT::i32)
Addr.Offset = (PPCSubTarget->isLittleEndian()) ? 0 : 4;
// Look at the currently assigned register for this instruction
// to determine the required register class.
unsigned AssignedReg = FuncInfo.ValueMap[I];
const TargetRegisterClass *RC =
AssignedReg ? MRI.getRegClass(AssignedReg) : nullptr;
unsigned ResultReg = 0;
if (!PPCEmitLoad(VT, ResultReg, Addr, RC, !IsSigned))
return 0;
return ResultReg;
}
// Attempt to fast-select a floating-point-to-integer conversion.
// FIXME: Once fast-isel has better support for VSX, conversions using
// direct moves should be implemented.
bool PPCFastISel::SelectFPToI(const Instruction *I, bool IsSigned) {
MVT DstVT, SrcVT;
Type *DstTy = I->getType();
if (!isTypeLegal(DstTy, DstVT))
return false;
if (DstVT != MVT::i32 && DstVT != MVT::i64)
return false;
// If we don't have FCTIDUZ and we need it, punt to SelectionDAG.
if (DstVT == MVT::i64 && !IsSigned && !PPCSubTarget->hasFPCVT())
return false;
Value *Src = I->getOperand(0);
Type *SrcTy = Src->getType();
if (!isTypeLegal(SrcTy, SrcVT))
return false;
if (SrcVT != MVT::f32 && SrcVT != MVT::f64)
return false;
unsigned SrcReg = getRegForValue(Src);
if (SrcReg == 0)
return false;
// Convert f32 to f64 if necessary. This is just a meaningless copy
// to get the register class right.
const TargetRegisterClass *InRC = MRI.getRegClass(SrcReg);
if (InRC == &PPC::F4RCRegClass) {
unsigned TmpReg = createResultReg(&PPC::F8RCRegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), TmpReg)
.addReg(SrcReg);
SrcReg = TmpReg;
}
// Determine the opcode for the conversion, which takes place
// entirely within FPRs.
unsigned DestReg = createResultReg(&PPC::F8RCRegClass);
unsigned Opc;
if (DstVT == MVT::i32)
if (IsSigned)
Opc = PPC::FCTIWZ;
else
Opc = PPCSubTarget->hasFPCVT() ? PPC::FCTIWUZ : PPC::FCTIDZ;
else
Opc = IsSigned ? PPC::FCTIDZ : PPC::FCTIDUZ;
// Generate the convert.
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), DestReg)
.addReg(SrcReg);
// Now move the integer value from a float register to an integer register.
unsigned IntReg = PPCMoveToIntReg(I, DstVT, DestReg, IsSigned);
if (IntReg == 0)
return false;
updateValueMap(I, IntReg);
return true;
}
// Attempt to fast-select a binary integer operation that isn't already
// handled automatically.
bool PPCFastISel::SelectBinaryIntOp(const Instruction *I, unsigned ISDOpcode) {
EVT DestVT = TLI.getValueType(DL, I->getType(), true);
// We can get here in the case when we have a binary operation on a non-legal
// type and the target independent selector doesn't know how to handle it.
if (DestVT != MVT::i16 && DestVT != MVT::i8)
return false;
// Look at the currently assigned register for this instruction
// to determine the required register class. If there is no register,
// make a conservative choice (don't assign R0).
unsigned AssignedReg = FuncInfo.ValueMap[I];
const TargetRegisterClass *RC =
(AssignedReg ? MRI.getRegClass(AssignedReg) :
&PPC::GPRC_and_GPRC_NOR0RegClass);
bool IsGPRC = RC->hasSuperClassEq(&PPC::GPRCRegClass);
unsigned Opc;
switch (ISDOpcode) {
default: return false;
case ISD::ADD:
Opc = IsGPRC ? PPC::ADD4 : PPC::ADD8;
break;
case ISD::OR:
Opc = IsGPRC ? PPC::OR : PPC::OR8;
break;
case ISD::SUB:
Opc = IsGPRC ? PPC::SUBF : PPC::SUBF8;
break;
}
unsigned ResultReg = createResultReg(RC ? RC : &PPC::G8RCRegClass);
unsigned SrcReg1 = getRegForValue(I->getOperand(0));
if (SrcReg1 == 0) return false;
// Handle case of small immediate operand.
if (const ConstantInt *ConstInt = dyn_cast<ConstantInt>(I->getOperand(1))) {
const APInt &CIVal = ConstInt->getValue();
int Imm = (int)CIVal.getSExtValue();
bool UseImm = true;
if (isInt<16>(Imm)) {
switch (Opc) {
default:
llvm_unreachable("Missing case!");
case PPC::ADD4:
Opc = PPC::ADDI;
MRI.setRegClass(SrcReg1, &PPC::GPRC_and_GPRC_NOR0RegClass);
break;
case PPC::ADD8:
Opc = PPC::ADDI8;
MRI.setRegClass(SrcReg1, &PPC::G8RC_and_G8RC_NOX0RegClass);
break;
case PPC::OR:
Opc = PPC::ORI;
break;
case PPC::OR8:
Opc = PPC::ORI8;
break;
case PPC::SUBF:
if (Imm == -32768)
UseImm = false;
else {
Opc = PPC::ADDI;
MRI.setRegClass(SrcReg1, &PPC::GPRC_and_GPRC_NOR0RegClass);
Imm = -Imm;
}
break;
case PPC::SUBF8:
if (Imm == -32768)
UseImm = false;
else {
Opc = PPC::ADDI8;
MRI.setRegClass(SrcReg1, &PPC::G8RC_and_G8RC_NOX0RegClass);
Imm = -Imm;
}
break;
}
if (UseImm) {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc),
ResultReg)
.addReg(SrcReg1)
.addImm(Imm);
updateValueMap(I, ResultReg);
return true;
}
}
}
// Reg-reg case.
unsigned SrcReg2 = getRegForValue(I->getOperand(1));
if (SrcReg2 == 0) return false;
// Reverse operands for subtract-from.
if (ISDOpcode == ISD::SUB)
std::swap(SrcReg1, SrcReg2);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg)
.addReg(SrcReg1).addReg(SrcReg2);
updateValueMap(I, ResultReg);
return true;
}
// Handle arguments to a call that we're attempting to fast-select.
// Return false if the arguments are too complex for us at the moment.
bool PPCFastISel::processCallArgs(SmallVectorImpl<Value*> &Args,
SmallVectorImpl<unsigned> &ArgRegs,
SmallVectorImpl<MVT> &ArgVTs,
SmallVectorImpl<ISD::ArgFlagsTy> &ArgFlags,
SmallVectorImpl<unsigned> &RegArgs,
CallingConv::ID CC,
unsigned &NumBytes,
bool IsVarArg) {
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CC, IsVarArg, *FuncInfo.MF, ArgLocs, *Context);
// Reserve space for the linkage area on the stack.
unsigned LinkageSize = PPCSubTarget->getFrameLowering()->getLinkageSize();
CCInfo.AllocateStack(LinkageSize, 8);
CCInfo.AnalyzeCallOperands(ArgVTs, ArgFlags, CC_PPC64_ELF_FIS);
// Bail out if we can't handle any of the arguments.
for (unsigned I = 0, E = ArgLocs.size(); I != E; ++I) {
CCValAssign &VA = ArgLocs[I];
MVT ArgVT = ArgVTs[VA.getValNo()];
// Skip vector arguments for now, as well as long double and
// uint128_t, and anything that isn't passed in a register.
if (ArgVT.isVector() || ArgVT.getSizeInBits() > 64 || ArgVT == MVT::i1 ||
!VA.isRegLoc() || VA.needsCustom())
return false;
// Skip bit-converted arguments for now.
if (VA.getLocInfo() == CCValAssign::BCvt)
return false;
}
// Get a count of how many bytes are to be pushed onto the stack.
NumBytes = CCInfo.getNextStackOffset();
// The prolog code of the callee may store up to 8 GPR argument registers to
// the stack, allowing va_start to index over them in memory if its varargs.
// Because we cannot tell if this is needed on the caller side, we have to
// conservatively assume that it is needed. As such, make sure we have at
// least enough stack space for the caller to store the 8 GPRs.
// FIXME: On ELFv2, it may be unnecessary to allocate the parameter area.
NumBytes = std::max(NumBytes, LinkageSize + 64);
// Issue CALLSEQ_START.
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TII.getCallFrameSetupOpcode()))
.addImm(NumBytes);
// Prepare to assign register arguments. Every argument uses up a
// GPR protocol register even if it's passed in a floating-point
// register (unless we're using the fast calling convention).
unsigned NextGPR = PPC::X3;
unsigned NextFPR = PPC::F1;
// Process arguments.
for (unsigned I = 0, E = ArgLocs.size(); I != E; ++I) {
CCValAssign &VA = ArgLocs[I];
unsigned Arg = ArgRegs[VA.getValNo()];
MVT ArgVT = ArgVTs[VA.getValNo()];
// Handle argument promotion and bitcasts.
switch (VA.getLocInfo()) {
default:
llvm_unreachable("Unknown loc info!");
case CCValAssign::Full:
break;
case CCValAssign::SExt: {
MVT DestVT = VA.getLocVT();
const TargetRegisterClass *RC =
(DestVT == MVT::i64) ? &PPC::G8RCRegClass : &PPC::GPRCRegClass;
unsigned TmpReg = createResultReg(RC);
if (!PPCEmitIntExt(ArgVT, Arg, DestVT, TmpReg, /*IsZExt*/false))
llvm_unreachable("Failed to emit a sext!");
ArgVT = DestVT;
Arg = TmpReg;
break;
}
case CCValAssign::AExt:
case CCValAssign::ZExt: {
MVT DestVT = VA.getLocVT();
const TargetRegisterClass *RC =
(DestVT == MVT::i64) ? &PPC::G8RCRegClass : &PPC::GPRCRegClass;
unsigned TmpReg = createResultReg(RC);
if (!PPCEmitIntExt(ArgVT, Arg, DestVT, TmpReg, /*IsZExt*/true))
llvm_unreachable("Failed to emit a zext!");
ArgVT = DestVT;
Arg = TmpReg;
break;
}
case CCValAssign::BCvt: {
// FIXME: Not yet handled.
llvm_unreachable("Should have bailed before getting here!");
break;
}
}
// Copy this argument to the appropriate register.
unsigned ArgReg;
if (ArgVT == MVT::f32 || ArgVT == MVT::f64) {
ArgReg = NextFPR++;
if (CC != CallingConv::Fast)
++NextGPR;
} else
ArgReg = NextGPR++;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), ArgReg).addReg(Arg);
RegArgs.push_back(ArgReg);
}
return true;
}
// For a call that we've determined we can fast-select, finish the
// call sequence and generate a copy to obtain the return value (if any).
bool PPCFastISel::finishCall(MVT RetVT, CallLoweringInfo &CLI, unsigned &NumBytes) {
CallingConv::ID CC = CLI.CallConv;
// Issue CallSEQ_END.
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TII.getCallFrameDestroyOpcode()))
.addImm(NumBytes).addImm(0);
// Next, generate a copy to obtain the return value.
// FIXME: No multi-register return values yet, though I don't foresee
// any real difficulties there.
if (RetVT != MVT::isVoid) {
SmallVector<CCValAssign, 16> RVLocs;
CCState CCInfo(CC, false, *FuncInfo.MF, RVLocs, *Context);
CCInfo.AnalyzeCallResult(RetVT, RetCC_PPC64_ELF_FIS);
CCValAssign &VA = RVLocs[0];
assert(RVLocs.size() == 1 && "No support for multi-reg return values!");
assert(VA.isRegLoc() && "Can only return in registers!");
MVT DestVT = VA.getValVT();
MVT CopyVT = DestVT;
// Ints smaller than a register still arrive in a full 64-bit
// register, so make sure we recognize this.
if (RetVT == MVT::i8 || RetVT == MVT::i16 || RetVT == MVT::i32)
CopyVT = MVT::i64;
unsigned SourcePhysReg = VA.getLocReg();
unsigned ResultReg = 0;
if (RetVT == CopyVT) {
const TargetRegisterClass *CpyRC = TLI.getRegClassFor(CopyVT);
ResultReg = createResultReg(CpyRC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), ResultReg)
.addReg(SourcePhysReg);
// If necessary, round the floating result to single precision.
} else if (CopyVT == MVT::f64) {
ResultReg = createResultReg(TLI.getRegClassFor(RetVT));
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::FRSP),
ResultReg).addReg(SourcePhysReg);
// If only the low half of a general register is needed, generate
// a GPRC copy instead of a G8RC copy. (EXTRACT_SUBREG can't be
// used along the fast-isel path (not lowered), and downstream logic
// also doesn't like a direct subreg copy on a physical reg.)
} else if (RetVT == MVT::i8 || RetVT == MVT::i16 || RetVT == MVT::i32) {
ResultReg = createResultReg(&PPC::GPRCRegClass);
// Convert physical register from G8RC to GPRC.
SourcePhysReg -= PPC::X0 - PPC::R0;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), ResultReg)
.addReg(SourcePhysReg);
}
assert(ResultReg && "ResultReg unset!");
CLI.InRegs.push_back(SourcePhysReg);
CLI.ResultReg = ResultReg;
CLI.NumResultRegs = 1;
}
return true;
}
bool PPCFastISel::fastLowerCall(CallLoweringInfo &CLI) {
CallingConv::ID CC = CLI.CallConv;
bool IsTailCall = CLI.IsTailCall;
bool IsVarArg = CLI.IsVarArg;
const Value *Callee = CLI.Callee;
const MCSymbol *Symbol = CLI.Symbol;
if (!Callee && !Symbol)
return false;
// Allow SelectionDAG isel to handle tail calls.
if (IsTailCall)
return false;
// Let SDISel handle vararg functions.
if (IsVarArg)
return false;
// Handle simple calls for now, with legal return types and
// those that can be extended.
Type *RetTy = CLI.RetTy;
MVT RetVT;
if (RetTy->isVoidTy())
RetVT = MVT::isVoid;
else if (!isTypeLegal(RetTy, RetVT) && RetVT != MVT::i16 &&
RetVT != MVT::i8)
return false;
else if (RetVT == MVT::i1 && PPCSubTarget->useCRBits())
// We can't handle boolean returns when CR bits are in use.
return false;
// FIXME: No multi-register return values yet.
if (RetVT != MVT::isVoid && RetVT != MVT::i8 && RetVT != MVT::i16 &&
RetVT != MVT::i32 && RetVT != MVT::i64 && RetVT != MVT::f32 &&
RetVT != MVT::f64) {
SmallVector<CCValAssign, 16> RVLocs;
CCState CCInfo(CC, IsVarArg, *FuncInfo.MF, RVLocs, *Context);
CCInfo.AnalyzeCallResult(RetVT, RetCC_PPC64_ELF_FIS);
if (RVLocs.size() > 1)
return false;
}
// Bail early if more than 8 arguments, as we only currently
// handle arguments passed in registers.
unsigned NumArgs = CLI.OutVals.size();
if (NumArgs > 8)
return false;
// Set up the argument vectors.
SmallVector<Value*, 8> Args;
SmallVector<unsigned, 8> ArgRegs;
SmallVector<MVT, 8> ArgVTs;
SmallVector<ISD::ArgFlagsTy, 8> ArgFlags;
Args.reserve(NumArgs);
ArgRegs.reserve(NumArgs);
ArgVTs.reserve(NumArgs);
ArgFlags.reserve(NumArgs);
for (unsigned i = 0, ie = NumArgs; i != ie; ++i) {
// Only handle easy calls for now. It would be reasonably easy
// to handle <= 8-byte structures passed ByVal in registers, but we
// have to ensure they are right-justified in the register.
ISD::ArgFlagsTy Flags = CLI.OutFlags[i];
if (Flags.isInReg() || Flags.isSRet() || Flags.isNest() || Flags.isByVal())
return false;
Value *ArgValue = CLI.OutVals[i];
Type *ArgTy = ArgValue->getType();
MVT ArgVT;
if (!isTypeLegal(ArgTy, ArgVT) && ArgVT != MVT::i16 && ArgVT != MVT::i8)
return false;
if (ArgVT.isVector())
return false;
unsigned Arg = getRegForValue(ArgValue);
if (Arg == 0)
return false;
Args.push_back(ArgValue);
ArgRegs.push_back(Arg);
ArgVTs.push_back(ArgVT);
ArgFlags.push_back(Flags);
}
// Process the arguments.
SmallVector<unsigned, 8> RegArgs;
unsigned NumBytes;
if (!processCallArgs(Args, ArgRegs, ArgVTs, ArgFlags,
RegArgs, CC, NumBytes, IsVarArg))
return false;
MachineInstrBuilder MIB;
// FIXME: No handling for function pointers yet. This requires
// implementing the function descriptor (OPD) setup.
const GlobalValue *GV = dyn_cast<GlobalValue>(Callee);
if (!GV) {
// patchpoints are a special case; they always dispatch to a pointer value.
// However, we don't actually want to generate the indirect call sequence
// here (that will be generated, as necessary, during asm printing), and
// the call we generate here will be erased by FastISel::selectPatchpoint,
// so don't try very hard...
if (CLI.IsPatchPoint)
MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::NOP));
else
return false;
} else {
// Build direct call with NOP for TOC restore.
// FIXME: We can and should optimize away the NOP for local calls.
MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(PPC::BL8_NOP));
// Add callee.
MIB.addGlobalAddress(GV);
}
// Add implicit physical register uses to the call.
for (unsigned II = 0, IE = RegArgs.size(); II != IE; ++II)
MIB.addReg(RegArgs[II], RegState::Implicit);
// Direct calls, in both the ELF V1 and V2 ABIs, need the TOC register live
// into the call.
PPCFuncInfo->setUsesTOCBasePtr();
MIB.addReg(PPC::X2, RegState::Implicit);
// Add a register mask with the call-preserved registers. Proper
// defs for return values will be added by setPhysRegsDeadExcept().
MIB.addRegMask(TRI.getCallPreservedMask(*FuncInfo.MF, CC));
CLI.Call = MIB;
// Finish off the call including any return values.
return finishCall(RetVT, CLI, NumBytes);
}
// Attempt to fast-select a return instruction.
bool PPCFastISel::SelectRet(const Instruction *I) {
if (!FuncInfo.CanLowerReturn)
return false;
if (TLI.supportSplitCSR(FuncInfo.MF))
return false;
const ReturnInst *Ret = cast<ReturnInst>(I);
const Function &F = *I->getParent()->getParent();
// Build a list of return value registers.
SmallVector<unsigned, 4> RetRegs;
CallingConv::ID CC = F.getCallingConv();
if (Ret->getNumOperands() > 0) {
SmallVector<ISD::OutputArg, 4> Outs;
GetReturnInfo(F.getReturnType(), F.getAttributes(), Outs, TLI, DL);
// Analyze operands of the call, assigning locations to each operand.
SmallVector<CCValAssign, 16> ValLocs;
CCState CCInfo(CC, F.isVarArg(), *FuncInfo.MF, ValLocs, *Context);
CCInfo.AnalyzeReturn(Outs, RetCC_PPC64_ELF_FIS);
const Value *RV = Ret->getOperand(0);
// FIXME: Only one output register for now.
if (ValLocs.size() > 1)
return false;
// Special case for returning a constant integer of any size - materialize
// the constant as an i64 and copy it to the return register.
if (const ConstantInt *CI = dyn_cast<ConstantInt>(RV)) {
CCValAssign &VA = ValLocs[0];
unsigned RetReg = VA.getLocReg();
// We still need to worry about properly extending the sign. For example,
// we could have only a single bit or a constant that needs zero
// extension rather than sign extension. Make sure we pass the return
// value extension property to integer materialization.
unsigned SrcReg =
PPCMaterializeInt(CI, MVT::i64, VA.getLocInfo() != CCValAssign::ZExt);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), RetReg).addReg(SrcReg);
RetRegs.push_back(RetReg);
} else {
unsigned Reg = getRegForValue(RV);
if (Reg == 0)
return false;
// Copy the result values into the output registers.
for (unsigned i = 0; i < ValLocs.size(); ++i) {
CCValAssign &VA = ValLocs[i];
assert(VA.isRegLoc() && "Can only return in registers!");
RetRegs.push_back(VA.getLocReg());
unsigned SrcReg = Reg + VA.getValNo();
EVT RVEVT = TLI.getValueType(DL, RV->getType());
if (!RVEVT.isSimple())
return false;
MVT RVVT = RVEVT.getSimpleVT();
MVT DestVT = VA.getLocVT();
if (RVVT != DestVT && RVVT != MVT::i8 &&
RVVT != MVT::i16 && RVVT != MVT::i32)
return false;
if (RVVT != DestVT) {
switch (VA.getLocInfo()) {
default:
llvm_unreachable("Unknown loc info!");
case CCValAssign::Full:
llvm_unreachable("Full value assign but types don't match?");
case CCValAssign::AExt:
case CCValAssign::ZExt: {
const TargetRegisterClass *RC =
(DestVT == MVT::i64) ? &PPC::G8RCRegClass : &PPC::GPRCRegClass;
unsigned TmpReg = createResultReg(RC);
if (!PPCEmitIntExt(RVVT, SrcReg, DestVT, TmpReg, true))
return false;
SrcReg = TmpReg;
break;
}
case CCValAssign::SExt: {
const TargetRegisterClass *RC =
(DestVT == MVT::i64) ? &PPC::G8RCRegClass : &PPC::GPRCRegClass;
unsigned TmpReg = createResultReg(RC);
if (!PPCEmitIntExt(RVVT, SrcReg, DestVT, TmpReg, false))
return false;
SrcReg = TmpReg;
break;
}
}
}
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), RetRegs[i])
.addReg(SrcReg);
}
}
}
MachineInstrBuilder MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(PPC::BLR8));
for (unsigned i = 0, e = RetRegs.size(); i != e; ++i)
MIB.addReg(RetRegs[i], RegState::Implicit);
return true;
}
// Attempt to emit an integer extend of SrcReg into DestReg. Both
// signed and zero extensions are supported. Return false if we
// can't handle it.
bool PPCFastISel::PPCEmitIntExt(MVT SrcVT, unsigned SrcReg, MVT DestVT,
unsigned DestReg, bool IsZExt) {
if (DestVT != MVT::i32 && DestVT != MVT::i64)
return false;
if (SrcVT != MVT::i8 && SrcVT != MVT::i16 && SrcVT != MVT::i32)
return false;
// Signed extensions use EXTSB, EXTSH, EXTSW.
if (!IsZExt) {
unsigned Opc;
if (SrcVT == MVT::i8)
Opc = (DestVT == MVT::i32) ? PPC::EXTSB : PPC::EXTSB8_32_64;
else if (SrcVT == MVT::i16)
Opc = (DestVT == MVT::i32) ? PPC::EXTSH : PPC::EXTSH8_32_64;
else {
assert(DestVT == MVT::i64 && "Signed extend from i32 to i32??");
Opc = PPC::EXTSW_32_64;
}
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), DestReg)
.addReg(SrcReg);
// Unsigned 32-bit extensions use RLWINM.
} else if (DestVT == MVT::i32) {
unsigned MB;
if (SrcVT == MVT::i8)
MB = 24;
else {
assert(SrcVT == MVT::i16 && "Unsigned extend from i32 to i32??");
MB = 16;
}
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::RLWINM),
DestReg)
.addReg(SrcReg).addImm(/*SH=*/0).addImm(MB).addImm(/*ME=*/31);
// Unsigned 64-bit extensions use RLDICL (with a 32-bit source).
} else {
unsigned MB;
if (SrcVT == MVT::i8)
MB = 56;
else if (SrcVT == MVT::i16)
MB = 48;
else
MB = 32;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(PPC::RLDICL_32_64), DestReg)
.addReg(SrcReg).addImm(/*SH=*/0).addImm(MB);
}
return true;
}
// Attempt to fast-select an indirect branch instruction.
bool PPCFastISel::SelectIndirectBr(const Instruction *I) {
unsigned AddrReg = getRegForValue(I->getOperand(0));
if (AddrReg == 0)
return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::MTCTR8))
.addReg(AddrReg);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::BCTR8));
const IndirectBrInst *IB = cast<IndirectBrInst>(I);
for (const BasicBlock *SuccBB : IB->successors())
FuncInfo.MBB->addSuccessor(FuncInfo.MBBMap[SuccBB]);
return true;
}
// Attempt to fast-select an integer truncate instruction.
bool PPCFastISel::SelectTrunc(const Instruction *I) {
Value *Src = I->getOperand(0);
EVT SrcVT = TLI.getValueType(DL, Src->getType(), true);
EVT DestVT = TLI.getValueType(DL, I->getType(), true);
if (SrcVT != MVT::i64 && SrcVT != MVT::i32 && SrcVT != MVT::i16)
return false;
if (DestVT != MVT::i32 && DestVT != MVT::i16 && DestVT != MVT::i8)
return false;
unsigned SrcReg = getRegForValue(Src);
if (!SrcReg)
return false;
// The only interesting case is when we need to switch register classes.
if (SrcVT == MVT::i64) {
unsigned ResultReg = createResultReg(&PPC::GPRCRegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY),
ResultReg).addReg(SrcReg, 0, PPC::sub_32);
SrcReg = ResultReg;
}
updateValueMap(I, SrcReg);
return true;
}
// Attempt to fast-select an integer extend instruction.
bool PPCFastISel::SelectIntExt(const Instruction *I) {
Type *DestTy = I->getType();
Value *Src = I->getOperand(0);
Type *SrcTy = Src->getType();
bool IsZExt = isa<ZExtInst>(I);
unsigned SrcReg = getRegForValue(Src);
if (!SrcReg) return false;
EVT SrcEVT, DestEVT;
SrcEVT = TLI.getValueType(DL, SrcTy, true);
DestEVT = TLI.getValueType(DL, DestTy, true);
if (!SrcEVT.isSimple())
return false;
if (!DestEVT.isSimple())
return false;
MVT SrcVT = SrcEVT.getSimpleVT();
MVT DestVT = DestEVT.getSimpleVT();
// If we know the register class needed for the result of this
// instruction, use it. Otherwise pick the register class of the
// correct size that does not contain X0/R0, since we don't know
// whether downstream uses permit that assignment.
unsigned AssignedReg = FuncInfo.ValueMap[I];
const TargetRegisterClass *RC =
(AssignedReg ? MRI.getRegClass(AssignedReg) :
(DestVT == MVT::i64 ? &PPC::G8RC_and_G8RC_NOX0RegClass :
&PPC::GPRC_and_GPRC_NOR0RegClass));
unsigned ResultReg = createResultReg(RC);
if (!PPCEmitIntExt(SrcVT, SrcReg, DestVT, ResultReg, IsZExt))
return false;
updateValueMap(I, ResultReg);
return true;
}
// Attempt to fast-select an instruction that wasn't handled by
// the table-generated machinery.
bool PPCFastISel::fastSelectInstruction(const Instruction *I) {
switch (I->getOpcode()) {
case Instruction::Load:
return SelectLoad(I);
case Instruction::Store:
return SelectStore(I);
case Instruction::Br:
return SelectBranch(I);
case Instruction::IndirectBr:
return SelectIndirectBr(I);
case Instruction::FPExt:
return SelectFPExt(I);
case Instruction::FPTrunc:
return SelectFPTrunc(I);
case Instruction::SIToFP:
return SelectIToFP(I, /*IsSigned*/ true);
case Instruction::UIToFP:
return SelectIToFP(I, /*IsSigned*/ false);
case Instruction::FPToSI:
return SelectFPToI(I, /*IsSigned*/ true);
case Instruction::FPToUI:
return SelectFPToI(I, /*IsSigned*/ false);
case Instruction::Add:
return SelectBinaryIntOp(I, ISD::ADD);
case Instruction::Or:
return SelectBinaryIntOp(I, ISD::OR);
case Instruction::Sub:
return SelectBinaryIntOp(I, ISD::SUB);
case Instruction::Call:
return selectCall(I);
case Instruction::Ret:
return SelectRet(I);
case Instruction::Trunc:
return SelectTrunc(I);
case Instruction::ZExt:
case Instruction::SExt:
return SelectIntExt(I);
// Here add other flavors of Instruction::XXX that automated
// cases don't catch. For example, switches are terminators
// that aren't yet handled.
default:
break;
}
return false;
}
// Materialize a floating-point constant into a register, and return
// the register number (or zero if we failed to handle it).
unsigned PPCFastISel::PPCMaterializeFP(const ConstantFP *CFP, MVT VT) {
// No plans to handle long double here.
if (VT != MVT::f32 && VT != MVT::f64)
return 0;
// All FP constants are loaded from the constant pool.
unsigned Align = DL.getPrefTypeAlignment(CFP->getType());
assert(Align > 0 && "Unexpectedly missing alignment information!");
unsigned Idx = MCP.getConstantPoolIndex(cast<Constant>(CFP), Align);
const TargetRegisterClass *RC =
(VT == MVT::f32) ? &PPC::F4RCRegClass : &PPC::F8RCRegClass;
unsigned DestReg = createResultReg(RC);
CodeModel::Model CModel = TM.getCodeModel();
MachineMemOperand *MMO = FuncInfo.MF->getMachineMemOperand(
MachinePointerInfo::getConstantPool(*FuncInfo.MF),
MachineMemOperand::MOLoad, (VT == MVT::f32) ? 4 : 8, Align);
unsigned Opc = (VT == MVT::f32) ? PPC::LFS : PPC::LFD;
unsigned TmpReg = createResultReg(&PPC::G8RC_and_G8RC_NOX0RegClass);
PPCFuncInfo->setUsesTOCBasePtr();
// For small code model, generate a LF[SD](0, LDtocCPT(Idx, X2)).
if (CModel == CodeModel::Small || CModel == CodeModel::JITDefault) {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::LDtocCPT),
TmpReg)
.addConstantPoolIndex(Idx).addReg(PPC::X2);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), DestReg)
.addImm(0).addReg(TmpReg).addMemOperand(MMO);
} else {
// Otherwise we generate LF[SD](Idx[lo], ADDIStocHA(X2, Idx)).
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::ADDIStocHA),
TmpReg).addReg(PPC::X2).addConstantPoolIndex(Idx);
// But for large code model, we must generate a LDtocL followed
// by the LF[SD].
if (CModel == CodeModel::Large) {
unsigned TmpReg2 = createResultReg(&PPC::G8RC_and_G8RC_NOX0RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::LDtocL),
TmpReg2).addConstantPoolIndex(Idx).addReg(TmpReg);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), DestReg)
.addImm(0)
.addReg(TmpReg2);
} else
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), DestReg)
.addConstantPoolIndex(Idx, 0, PPCII::MO_TOC_LO)
.addReg(TmpReg)
.addMemOperand(MMO);
}
return DestReg;
}
// Materialize the address of a global value into a register, and return
// the register number (or zero if we failed to handle it).
unsigned PPCFastISel::PPCMaterializeGV(const GlobalValue *GV, MVT VT) {
assert(VT == MVT::i64 && "Non-address!");
const TargetRegisterClass *RC = &PPC::G8RC_and_G8RC_NOX0RegClass;
unsigned DestReg = createResultReg(RC);
// Global values may be plain old object addresses, TLS object
// addresses, constant pool entries, or jump tables. How we generate
// code for these may depend on small, medium, or large code model.
CodeModel::Model CModel = TM.getCodeModel();
// FIXME: Jump tables are not yet required because fast-isel doesn't
// handle switches; if that changes, we need them as well. For now,
// what follows assumes everything's a generic (or TLS) global address.
// FIXME: We don't yet handle the complexity of TLS.
if (GV->isThreadLocal())
return 0;
PPCFuncInfo->setUsesTOCBasePtr();
// For small code model, generate a simple TOC load.
if (CModel == CodeModel::Small || CModel == CodeModel::JITDefault)
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::LDtoc),
DestReg)
.addGlobalAddress(GV)
.addReg(PPC::X2);
else {
// If the address is an externally defined symbol, a symbol with common
// or externally available linkage, a non-local function address, or a
// jump table address (not yet needed), or if we are generating code
// for large code model, we generate:
// LDtocL(GV, ADDIStocHA(%X2, GV))
// Otherwise we generate:
// ADDItocL(ADDIStocHA(%X2, GV), GV)
// Either way, start with the ADDIStocHA:
unsigned HighPartReg = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::ADDIStocHA),
HighPartReg).addReg(PPC::X2).addGlobalAddress(GV);
unsigned char GVFlags = PPCSubTarget->classifyGlobalReference(GV);
if (GVFlags & PPCII::MO_NLP_FLAG) {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::LDtocL),
DestReg).addGlobalAddress(GV).addReg(HighPartReg);
} else {
// Otherwise generate the ADDItocL.
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::ADDItocL),
DestReg).addReg(HighPartReg).addGlobalAddress(GV);
}
}
return DestReg;
}
// Materialize a 32-bit integer constant into a register, and return
// the register number (or zero if we failed to handle it).
unsigned PPCFastISel::PPCMaterialize32BitInt(int64_t Imm,
const TargetRegisterClass *RC) {
unsigned Lo = Imm & 0xFFFF;
unsigned Hi = (Imm >> 16) & 0xFFFF;
unsigned ResultReg = createResultReg(RC);
bool IsGPRC = RC->hasSuperClassEq(&PPC::GPRCRegClass);
if (isInt<16>(Imm))
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(IsGPRC ? PPC::LI : PPC::LI8), ResultReg)
.addImm(Imm);
else if (Lo) {
// Both Lo and Hi have nonzero bits.
unsigned TmpReg = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(IsGPRC ? PPC::LIS : PPC::LIS8), TmpReg)
.addImm(Hi);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(IsGPRC ? PPC::ORI : PPC::ORI8), ResultReg)
.addReg(TmpReg).addImm(Lo);
} else
// Just Hi bits.
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(IsGPRC ? PPC::LIS : PPC::LIS8), ResultReg)
.addImm(Hi);
return ResultReg;
}
// Materialize a 64-bit integer constant into a register, and return
// the register number (or zero if we failed to handle it).
unsigned PPCFastISel::PPCMaterialize64BitInt(int64_t Imm,
const TargetRegisterClass *RC) {
unsigned Remainder = 0;
unsigned Shift = 0;
// If the value doesn't fit in 32 bits, see if we can shift it
// so that it fits in 32 bits.
if (!isInt<32>(Imm)) {
Shift = countTrailingZeros<uint64_t>(Imm);
int64_t ImmSh = static_cast<uint64_t>(Imm) >> Shift;
if (isInt<32>(ImmSh))
Imm = ImmSh;
else {
Remainder = Imm;
Shift = 32;
Imm >>= 32;
}
}
// Handle the high-order 32 bits (if shifted) or the whole 32 bits
// (if not shifted).
unsigned TmpReg1 = PPCMaterialize32BitInt(Imm, RC);
if (!Shift)
return TmpReg1;
// If upper 32 bits were not zero, we've built them and need to shift
// them into place.
unsigned TmpReg2;
if (Imm) {
TmpReg2 = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::RLDICR),
TmpReg2).addReg(TmpReg1).addImm(Shift).addImm(63 - Shift);
} else
TmpReg2 = TmpReg1;
unsigned TmpReg3, Hi, Lo;
if ((Hi = (Remainder >> 16) & 0xFFFF)) {
TmpReg3 = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::ORIS8),
TmpReg3).addReg(TmpReg2).addImm(Hi);
} else
TmpReg3 = TmpReg2;
if ((Lo = Remainder & 0xFFFF)) {
unsigned ResultReg = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::ORI8),
ResultReg).addReg(TmpReg3).addImm(Lo);
return ResultReg;
}
return TmpReg3;
}
// Materialize an integer constant into a register, and return
// the register number (or zero if we failed to handle it).
unsigned PPCFastISel::PPCMaterializeInt(const ConstantInt *CI, MVT VT,
bool UseSExt) {
// If we're using CR bit registers for i1 values, handle that as a special
// case first.
if (VT == MVT::i1 && PPCSubTarget->useCRBits()) {
unsigned ImmReg = createResultReg(&PPC::CRBITRCRegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(CI->isZero() ? PPC::CRUNSET : PPC::CRSET), ImmReg);
return ImmReg;
}
if (VT != MVT::i64 && VT != MVT::i32 && VT != MVT::i16 && VT != MVT::i8 &&
VT != MVT::i1)
return 0;
const TargetRegisterClass *RC =
((VT == MVT::i64) ? &PPC::G8RCRegClass : &PPC::GPRCRegClass);
int64_t Imm = UseSExt ? CI->getSExtValue() : CI->getZExtValue();
// If the constant is in range, use a load-immediate.
// Since LI will sign extend the constant we need to make sure that for
// our zeroext constants that the sign extended constant fits into 16-bits -
// a range of 0..0x7fff.
if (isInt<16>(Imm)) {
unsigned Opc = (VT == MVT::i64) ? PPC::LI8 : PPC::LI;
unsigned ImmReg = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ImmReg)
.addImm(Imm);
return ImmReg;
}
// Construct the constant piecewise.
if (VT == MVT::i64)
return PPCMaterialize64BitInt(Imm, RC);
else if (VT == MVT::i32)
return PPCMaterialize32BitInt(Imm, RC);
return 0;
}
// Materialize a constant into a register, and return the register
// number (or zero if we failed to handle it).
unsigned PPCFastISel::fastMaterializeConstant(const Constant *C) {
EVT CEVT = TLI.getValueType(DL, C->getType(), true);
// Only handle simple types.
if (!CEVT.isSimple()) return 0;
MVT VT = CEVT.getSimpleVT();
if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C))
return PPCMaterializeFP(CFP, VT);
else if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
return PPCMaterializeGV(GV, VT);
else if (const ConstantInt *CI = dyn_cast<ConstantInt>(C))
// Note that the code in FunctionLoweringInfo::ComputePHILiveOutRegInfo
// assumes that constant PHI operands will be zero extended, and failure to
// match that assumption will cause problems if we sign extend here but
// some user of a PHI is in a block for which we fall back to full SDAG
// instruction selection.
return PPCMaterializeInt(CI, VT, false);
return 0;
}
// Materialize the address created by an alloca into a register, and
// return the register number (or zero if we failed to handle it).
unsigned PPCFastISel::fastMaterializeAlloca(const AllocaInst *AI) {
// Don't handle dynamic allocas.
if (!FuncInfo.StaticAllocaMap.count(AI)) return 0;
MVT VT;
if (!isLoadTypeLegal(AI->getType(), VT)) return 0;
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI != FuncInfo.StaticAllocaMap.end()) {
unsigned ResultReg = createResultReg(&PPC::G8RC_and_G8RC_NOX0RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::ADDI8),
ResultReg).addFrameIndex(SI->second).addImm(0);
return ResultReg;
}
return 0;
}
// Fold loads into extends when possible.
// FIXME: We can have multiple redundant extend/trunc instructions
// following a load. The folding only picks up one. Extend this
// to check subsequent instructions for the same pattern and remove
// them. Thus ResultReg should be the def reg for the last redundant
// instruction in a chain, and all intervening instructions can be
// removed from parent. Change test/CodeGen/PowerPC/fast-isel-fold.ll
// to add ELF64-NOT: rldicl to the appropriate tests when this works.
bool PPCFastISel::tryToFoldLoadIntoMI(MachineInstr *MI, unsigned OpNo,
const LoadInst *LI) {
// Verify we have a legal type before going any further.
MVT VT;
if (!isLoadTypeLegal(LI->getType(), VT))
return false;
// Combine load followed by zero- or sign-extend.
bool IsZExt = false;
switch(MI->getOpcode()) {
default:
return false;
case PPC::RLDICL:
case PPC::RLDICL_32_64: {
IsZExt = true;
unsigned MB = MI->getOperand(3).getImm();
if ((VT == MVT::i8 && MB <= 56) ||
(VT == MVT::i16 && MB <= 48) ||
(VT == MVT::i32 && MB <= 32))
break;
return false;
}
case PPC::RLWINM:
case PPC::RLWINM8: {
IsZExt = true;
unsigned MB = MI->getOperand(3).getImm();
if ((VT == MVT::i8 && MB <= 24) ||
(VT == MVT::i16 && MB <= 16))
break;
return false;
}
case PPC::EXTSB:
case PPC::EXTSB8:
case PPC::EXTSB8_32_64:
/* There is no sign-extending load-byte instruction. */
return false;
case PPC::EXTSH:
case PPC::EXTSH8:
case PPC::EXTSH8_32_64: {
if (VT != MVT::i16 && VT != MVT::i8)
return false;
break;
}
case PPC::EXTSW:
case PPC::EXTSW_32_64: {
if (VT != MVT::i32 && VT != MVT::i16 && VT != MVT::i8)
return false;
break;
}
}
// See if we can handle this address.
Address Addr;
if (!PPCComputeAddress(LI->getOperand(0), Addr))
return false;
unsigned ResultReg = MI->getOperand(0).getReg();
if (!PPCEmitLoad(VT, ResultReg, Addr, nullptr, IsZExt))
return false;
MI->eraseFromParent();
return true;
}
// Attempt to lower call arguments in a faster way than done by
// the selection DAG code.
bool PPCFastISel::fastLowerArguments() {
// Defer to normal argument lowering for now. It's reasonably
// efficient. Consider doing something like ARM to handle the
// case where all args fit in registers, no varargs, no float
// or vector args.
return false;
}
// Handle materializing integer constants into a register. This is not
// automatically generated for PowerPC, so must be explicitly created here.
unsigned PPCFastISel::fastEmit_i(MVT Ty, MVT VT, unsigned Opc, uint64_t Imm) {
if (Opc != ISD::Constant)
return 0;
// If we're using CR bit registers for i1 values, handle that as a special
// case first.
if (VT == MVT::i1 && PPCSubTarget->useCRBits()) {
unsigned ImmReg = createResultReg(&PPC::CRBITRCRegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(Imm == 0 ? PPC::CRUNSET : PPC::CRSET), ImmReg);
return ImmReg;
}
if (VT != MVT::i64 && VT != MVT::i32 && VT != MVT::i16 && VT != MVT::i8 &&
VT != MVT::i1)
return 0;
const TargetRegisterClass *RC = ((VT == MVT::i64) ? &PPC::G8RCRegClass :
&PPC::GPRCRegClass);
if (VT == MVT::i64)
return PPCMaterialize64BitInt(Imm, RC);
else
return PPCMaterialize32BitInt(Imm, RC);
}
// Override for ADDI and ADDI8 to set the correct register class
// on RHS operand 0. The automatic infrastructure naively assumes
// GPRC for i32 and G8RC for i64; the concept of "no R0" is lost
// for these cases. At the moment, none of the other automatically
// generated RI instructions require special treatment. However, once
// SelectSelect is implemented, "isel" requires similar handling.
//
// Also be conservative about the output register class. Avoid
// assigning R0 or X0 to the output register for GPRC and G8RC
// register classes, as any such result could be used in ADDI, etc.,
// where those regs have another meaning.
unsigned PPCFastISel::fastEmitInst_ri(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
uint64_t Imm) {
if (MachineInstOpcode == PPC::ADDI)
MRI.setRegClass(Op0, &PPC::GPRC_and_GPRC_NOR0RegClass);
else if (MachineInstOpcode == PPC::ADDI8)
MRI.setRegClass(Op0, &PPC::G8RC_and_G8RC_NOX0RegClass);
const TargetRegisterClass *UseRC =
(RC == &PPC::GPRCRegClass ? &PPC::GPRC_and_GPRC_NOR0RegClass :
(RC == &PPC::G8RCRegClass ? &PPC::G8RC_and_G8RC_NOX0RegClass : RC));
return FastISel::fastEmitInst_ri(MachineInstOpcode, UseRC,
Op0, Op0IsKill, Imm);
}
// Override for instructions with one register operand to avoid use of
// R0/X0. The automatic infrastructure isn't aware of the context so
// we must be conservative.
unsigned PPCFastISel::fastEmitInst_r(unsigned MachineInstOpcode,
const TargetRegisterClass* RC,
unsigned Op0, bool Op0IsKill) {
const TargetRegisterClass *UseRC =
(RC == &PPC::GPRCRegClass ? &PPC::GPRC_and_GPRC_NOR0RegClass :
(RC == &PPC::G8RCRegClass ? &PPC::G8RC_and_G8RC_NOX0RegClass : RC));
return FastISel::fastEmitInst_r(MachineInstOpcode, UseRC, Op0, Op0IsKill);
}
// Override for instructions with two register operands to avoid use
// of R0/X0. The automatic infrastructure isn't aware of the context
// so we must be conservative.
unsigned PPCFastISel::fastEmitInst_rr(unsigned MachineInstOpcode,
const TargetRegisterClass* RC,
unsigned Op0, bool Op0IsKill,
unsigned Op1, bool Op1IsKill) {
const TargetRegisterClass *UseRC =
(RC == &PPC::GPRCRegClass ? &PPC::GPRC_and_GPRC_NOR0RegClass :
(RC == &PPC::G8RCRegClass ? &PPC::G8RC_and_G8RC_NOX0RegClass : RC));
return FastISel::fastEmitInst_rr(MachineInstOpcode, UseRC, Op0, Op0IsKill,
Op1, Op1IsKill);
}
namespace llvm {
// Create the fast instruction selector for PowerPC64 ELF.
FastISel *PPC::createFastISel(FunctionLoweringInfo &FuncInfo,
const TargetLibraryInfo *LibInfo) {
// Only available on 64-bit ELF for now.
const PPCSubtarget &Subtarget = FuncInfo.MF->getSubtarget<PPCSubtarget>();
if (Subtarget.isPPC64() && Subtarget.isSVR4ABI())
return new PPCFastISel(FuncInfo, LibInfo);
return nullptr;
}
}
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