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llvm-project/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp

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//===- AArch64InstructionSelector.cpp ----------------------------*- C++ -*-==//
//
// 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
//
//===----------------------------------------------------------------------===//
/// \file
/// This file implements the targeting of the InstructionSelector class for
/// AArch64.
/// \todo This should be generated by TableGen.
//===----------------------------------------------------------------------===//
#include "AArch64InstrInfo.h"
#include "AArch64MachineFunctionInfo.h"
#include "AArch64RegisterBankInfo.h"
#include "AArch64RegisterInfo.h"
#include "AArch64Subtarget.h"
#include "AArch64TargetMachine.h"
#include "MCTargetDesc/AArch64AddressingModes.h"
#include "llvm/CodeGen/GlobalISel/InstructionSelector.h"
#include "llvm/CodeGen/GlobalISel/InstructionSelectorImpl.h"
#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
#include "llvm/CodeGen/GlobalISel/Utils.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/IR/Type.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#define DEBUG_TYPE "aarch64-isel"
using namespace llvm;
namespace {
#define GET_GLOBALISEL_PREDICATE_BITSET
#include "AArch64GenGlobalISel.inc"
#undef GET_GLOBALISEL_PREDICATE_BITSET
class AArch64InstructionSelector : public InstructionSelector {
public:
AArch64InstructionSelector(const AArch64TargetMachine &TM,
const AArch64Subtarget &STI,
const AArch64RegisterBankInfo &RBI);
bool select(MachineInstr &I, CodeGenCoverage &CoverageInfo) const override;
static const char *getName() { return DEBUG_TYPE; }
private:
/// tblgen-erated 'select' implementation, used as the initial selector for
/// the patterns that don't require complex C++.
bool selectImpl(MachineInstr &I, CodeGenCoverage &CoverageInfo) const;
bool selectVaStartAAPCS(MachineInstr &I, MachineFunction &MF,
MachineRegisterInfo &MRI) const;
bool selectVaStartDarwin(MachineInstr &I, MachineFunction &MF,
MachineRegisterInfo &MRI) const;
bool selectCompareBranch(MachineInstr &I, MachineFunction &MF,
MachineRegisterInfo &MRI) const;
// Helper to generate an equivalent of scalar_to_vector into a new register,
// returned via 'Dst'.
bool emitScalarToVector(unsigned &Dst, const LLT DstTy,
const TargetRegisterClass *DstRC, unsigned Scalar,
MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
MachineRegisterInfo &MRI) const;
bool selectBuildVector(MachineInstr &I, MachineRegisterInfo &MRI) const;
bool selectMergeValues(MachineInstr &I, MachineRegisterInfo &MRI) const;
bool selectUnmergeValues(MachineInstr &I, MachineRegisterInfo &MRI) const;
ComplexRendererFns selectArithImmed(MachineOperand &Root) const;
ComplexRendererFns selectAddrModeUnscaled(MachineOperand &Root,
unsigned Size) const;
ComplexRendererFns selectAddrModeUnscaled8(MachineOperand &Root) const {
return selectAddrModeUnscaled(Root, 1);
}
ComplexRendererFns selectAddrModeUnscaled16(MachineOperand &Root) const {
return selectAddrModeUnscaled(Root, 2);
}
ComplexRendererFns selectAddrModeUnscaled32(MachineOperand &Root) const {
return selectAddrModeUnscaled(Root, 4);
}
ComplexRendererFns selectAddrModeUnscaled64(MachineOperand &Root) const {
return selectAddrModeUnscaled(Root, 8);
}
ComplexRendererFns selectAddrModeUnscaled128(MachineOperand &Root) const {
return selectAddrModeUnscaled(Root, 16);
}
ComplexRendererFns selectAddrModeIndexed(MachineOperand &Root,
unsigned Size) const;
template <int Width>
ComplexRendererFns selectAddrModeIndexed(MachineOperand &Root) const {
return selectAddrModeIndexed(Root, Width / 8);
}
void renderTruncImm(MachineInstrBuilder &MIB, const MachineInstr &MI) const;
// Materialize a GlobalValue or BlockAddress using a movz+movk sequence.
void materializeLargeCMVal(MachineInstr &I, const Value *V,
unsigned char OpFlags) const;
const AArch64TargetMachine &TM;
const AArch64Subtarget &STI;
const AArch64InstrInfo &TII;
const AArch64RegisterInfo &TRI;
const AArch64RegisterBankInfo &RBI;
#define GET_GLOBALISEL_PREDICATES_DECL
#include "AArch64GenGlobalISel.inc"
#undef GET_GLOBALISEL_PREDICATES_DECL
// We declare the temporaries used by selectImpl() in the class to minimize the
// cost of constructing placeholder values.
#define GET_GLOBALISEL_TEMPORARIES_DECL
#include "AArch64GenGlobalISel.inc"
#undef GET_GLOBALISEL_TEMPORARIES_DECL
};
} // end anonymous namespace
#define GET_GLOBALISEL_IMPL
#include "AArch64GenGlobalISel.inc"
#undef GET_GLOBALISEL_IMPL
AArch64InstructionSelector::AArch64InstructionSelector(
const AArch64TargetMachine &TM, const AArch64Subtarget &STI,
const AArch64RegisterBankInfo &RBI)
: InstructionSelector(), TM(TM), STI(STI), TII(*STI.getInstrInfo()),
TRI(*STI.getRegisterInfo()), RBI(RBI),
#define GET_GLOBALISEL_PREDICATES_INIT
#include "AArch64GenGlobalISel.inc"
#undef GET_GLOBALISEL_PREDICATES_INIT
#define GET_GLOBALISEL_TEMPORARIES_INIT
#include "AArch64GenGlobalISel.inc"
#undef GET_GLOBALISEL_TEMPORARIES_INIT
{
}
// FIXME: This should be target-independent, inferred from the types declared
// for each class in the bank.
static const TargetRegisterClass *
getRegClassForTypeOnBank(LLT Ty, const RegisterBank &RB,
const RegisterBankInfo &RBI,
bool GetAllRegSet = false) {
if (RB.getID() == AArch64::GPRRegBankID) {
if (Ty.getSizeInBits() <= 32)
return GetAllRegSet ? &AArch64::GPR32allRegClass
: &AArch64::GPR32RegClass;
if (Ty.getSizeInBits() == 64)
return GetAllRegSet ? &AArch64::GPR64allRegClass
: &AArch64::GPR64RegClass;
return nullptr;
}
if (RB.getID() == AArch64::FPRRegBankID) {
if (Ty.getSizeInBits() <= 16)
return &AArch64::FPR16RegClass;
if (Ty.getSizeInBits() == 32)
return &AArch64::FPR32RegClass;
if (Ty.getSizeInBits() == 64)
return &AArch64::FPR64RegClass;
if (Ty.getSizeInBits() == 128)
return &AArch64::FPR128RegClass;
return nullptr;
}
return nullptr;
}
/// Given a register bank, and size in bits, return the smallest register class
/// that can represent that combination.
const TargetRegisterClass *getMinClassForRegBank(const RegisterBank &RB,
unsigned SizeInBits,
bool GetAllRegSet = false) {
unsigned RegBankID = RB.getID();
if (RegBankID == AArch64::GPRRegBankID) {
if (SizeInBits <= 32)
return GetAllRegSet ? &AArch64::GPR32allRegClass
: &AArch64::GPR32RegClass;
if (SizeInBits == 64)
return GetAllRegSet ? &AArch64::GPR64allRegClass
: &AArch64::GPR64RegClass;
}
if (RegBankID == AArch64::FPRRegBankID) {
switch (SizeInBits) {
default:
return nullptr;
case 8:
return &AArch64::FPR8RegClass;
case 16:
return &AArch64::FPR16RegClass;
case 32:
return &AArch64::FPR32RegClass;
case 64:
return &AArch64::FPR64RegClass;
case 128:
return &AArch64::FPR128RegClass;
}
}
return nullptr;
}
/// Returns the correct subregister to use for a given register class.
static bool getSubRegForClass(const TargetRegisterClass *RC,
const TargetRegisterInfo &TRI, unsigned &SubReg) {
switch (TRI.getRegSizeInBits(*RC)) {
case 8:
SubReg = AArch64::bsub;
break;
case 16:
SubReg = AArch64::hsub;
break;
case 32:
if (RC == &AArch64::GPR32RegClass)
SubReg = AArch64::sub_32;
else
SubReg = AArch64::ssub;
break;
case 64:
SubReg = AArch64::dsub;
break;
default:
LLVM_DEBUG(
dbgs() << "Couldn't find appropriate subregister for register class.");
return false;
}
return true;
}
/// Check whether \p I is a currently unsupported binary operation:
/// - it has an unsized type
/// - an operand is not a vreg
/// - all operands are not in the same bank
/// These are checks that should someday live in the verifier, but right now,
/// these are mostly limitations of the aarch64 selector.
static bool unsupportedBinOp(const MachineInstr &I,
const AArch64RegisterBankInfo &RBI,
const MachineRegisterInfo &MRI,
const AArch64RegisterInfo &TRI) {
LLT Ty = MRI.getType(I.getOperand(0).getReg());
if (!Ty.isValid()) {
LLVM_DEBUG(dbgs() << "Generic binop register should be typed\n");
return true;
}
const RegisterBank *PrevOpBank = nullptr;
for (auto &MO : I.operands()) {
// FIXME: Support non-register operands.
if (!MO.isReg()) {
LLVM_DEBUG(dbgs() << "Generic inst non-reg operands are unsupported\n");
return true;
}
// FIXME: Can generic operations have physical registers operands? If
// so, this will need to be taught about that, and we'll need to get the
// bank out of the minimal class for the register.
// Either way, this needs to be documented (and possibly verified).
if (!TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
LLVM_DEBUG(dbgs() << "Generic inst has physical register operand\n");
return true;
}
const RegisterBank *OpBank = RBI.getRegBank(MO.getReg(), MRI, TRI);
if (!OpBank) {
LLVM_DEBUG(dbgs() << "Generic register has no bank or class\n");
return true;
}
if (PrevOpBank && OpBank != PrevOpBank) {
LLVM_DEBUG(dbgs() << "Generic inst operands have different banks\n");
return true;
}
PrevOpBank = OpBank;
}
return false;
}
/// Select the AArch64 opcode for the basic binary operation \p GenericOpc
/// (such as G_OR or G_SDIV), appropriate for the register bank \p RegBankID
/// and of size \p OpSize.
/// \returns \p GenericOpc if the combination is unsupported.
static unsigned selectBinaryOp(unsigned GenericOpc, unsigned RegBankID,
unsigned OpSize) {
switch (RegBankID) {
case AArch64::GPRRegBankID:
if (OpSize == 32) {
switch (GenericOpc) {
case TargetOpcode::G_SHL:
return AArch64::LSLVWr;
case TargetOpcode::G_LSHR:
return AArch64::LSRVWr;
case TargetOpcode::G_ASHR:
return AArch64::ASRVWr;
default:
return GenericOpc;
}
} else if (OpSize == 64) {
switch (GenericOpc) {
case TargetOpcode::G_GEP:
return AArch64::ADDXrr;
case TargetOpcode::G_SHL:
return AArch64::LSLVXr;
case TargetOpcode::G_LSHR:
return AArch64::LSRVXr;
case TargetOpcode::G_ASHR:
return AArch64::ASRVXr;
default:
return GenericOpc;
}
}
break;
case AArch64::FPRRegBankID:
switch (OpSize) {
case 32:
switch (GenericOpc) {
case TargetOpcode::G_FADD:
return AArch64::FADDSrr;
case TargetOpcode::G_FSUB:
return AArch64::FSUBSrr;
case TargetOpcode::G_FMUL:
return AArch64::FMULSrr;
case TargetOpcode::G_FDIV:
return AArch64::FDIVSrr;
default:
return GenericOpc;
}
case 64:
switch (GenericOpc) {
case TargetOpcode::G_FADD:
return AArch64::FADDDrr;
case TargetOpcode::G_FSUB:
return AArch64::FSUBDrr;
case TargetOpcode::G_FMUL:
return AArch64::FMULDrr;
case TargetOpcode::G_FDIV:
return AArch64::FDIVDrr;
case TargetOpcode::G_OR:
return AArch64::ORRv8i8;
default:
return GenericOpc;
}
}
break;
}
return GenericOpc;
}
/// Select the AArch64 opcode for the G_LOAD or G_STORE operation \p GenericOpc,
/// appropriate for the (value) register bank \p RegBankID and of memory access
/// size \p OpSize. This returns the variant with the base+unsigned-immediate
/// addressing mode (e.g., LDRXui).
/// \returns \p GenericOpc if the combination is unsupported.
static unsigned selectLoadStoreUIOp(unsigned GenericOpc, unsigned RegBankID,
unsigned OpSize) {
const bool isStore = GenericOpc == TargetOpcode::G_STORE;
switch (RegBankID) {
case AArch64::GPRRegBankID:
switch (OpSize) {
case 8:
return isStore ? AArch64::STRBBui : AArch64::LDRBBui;
case 16:
return isStore ? AArch64::STRHHui : AArch64::LDRHHui;
case 32:
return isStore ? AArch64::STRWui : AArch64::LDRWui;
case 64:
return isStore ? AArch64::STRXui : AArch64::LDRXui;
}
break;
case AArch64::FPRRegBankID:
switch (OpSize) {
case 8:
return isStore ? AArch64::STRBui : AArch64::LDRBui;
case 16:
return isStore ? AArch64::STRHui : AArch64::LDRHui;
case 32:
return isStore ? AArch64::STRSui : AArch64::LDRSui;
case 64:
return isStore ? AArch64::STRDui : AArch64::LDRDui;
}
break;
}
return GenericOpc;
}
#ifndef NDEBUG
/// Helper function that verifies that we have a valid copy at the end of
/// selectCopy. Verifies that the source and dest have the expected sizes and
/// then returns true.
static bool isValidCopy(const MachineInstr &I, const RegisterBank &DstBank,
const MachineRegisterInfo &MRI,
const TargetRegisterInfo &TRI,
const RegisterBankInfo &RBI) {
const unsigned DstReg = I.getOperand(0).getReg();
const unsigned SrcReg = I.getOperand(1).getReg();
const unsigned DstSize = RBI.getSizeInBits(DstReg, MRI, TRI);
const unsigned SrcSize = RBI.getSizeInBits(SrcReg, MRI, TRI);
// Make sure the size of the source and dest line up.
assert(
(DstSize == SrcSize ||
// Copies are a mean to setup initial types, the number of
// bits may not exactly match.
(TargetRegisterInfo::isPhysicalRegister(SrcReg) && DstSize <= SrcSize) ||
// Copies are a mean to copy bits around, as long as we are
// on the same register class, that's fine. Otherwise, that
// means we need some SUBREG_TO_REG or AND & co.
(((DstSize + 31) / 32 == (SrcSize + 31) / 32) && DstSize > SrcSize)) &&
"Copy with different width?!");
// Check the size of the destination.
assert((DstSize <= 64 || DstBank.getID() == AArch64::FPRRegBankID) &&
"GPRs cannot get more than 64-bit width values");
return true;
}
#endif
/// Helper function for selectCopy. Inserts a subregister copy from
/// \p *From to \p *To, linking it up to \p I.
///
/// e.g, given I = "Dst = COPY SrcReg", we'll transform that into
///
/// CopyReg (From class) = COPY SrcReg
/// SubRegCopy (To class) = COPY CopyReg:SubReg
/// Dst = COPY SubRegCopy
static bool selectSubregisterCopy(MachineInstr &I, const TargetInstrInfo &TII,
MachineRegisterInfo &MRI,
const RegisterBankInfo &RBI, unsigned SrcReg,
const TargetRegisterClass *From,
const TargetRegisterClass *To,
unsigned SubReg) {
unsigned CopyReg = MRI.createVirtualRegister(From);
BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(AArch64::COPY), CopyReg)
.addUse(SrcReg);
unsigned SubRegCopy = MRI.createVirtualRegister(To);
BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(TargetOpcode::COPY),
SubRegCopy)
.addUse(CopyReg, 0, SubReg);
MachineOperand &RegOp = I.getOperand(1);
RegOp.setReg(SubRegCopy);
// It's possible that the destination register won't be constrained. Make
// sure that happens.
if (!TargetRegisterInfo::isPhysicalRegister(I.getOperand(0).getReg()))
RBI.constrainGenericRegister(I.getOperand(0).getReg(), *To, MRI);
return true;
}
static bool selectCopy(MachineInstr &I, const TargetInstrInfo &TII,
MachineRegisterInfo &MRI, const TargetRegisterInfo &TRI,
const RegisterBankInfo &RBI) {
unsigned DstReg = I.getOperand(0).getReg();
unsigned SrcReg = I.getOperand(1).getReg();
const RegisterBank &DstRegBank = *RBI.getRegBank(DstReg, MRI, TRI);
const RegisterBank &SrcRegBank = *RBI.getRegBank(SrcReg, MRI, TRI);
const TargetRegisterClass *DstRC = getMinClassForRegBank(
DstRegBank, RBI.getSizeInBits(DstReg, MRI, TRI), true);
if (!DstRC) {
LLVM_DEBUG(dbgs() << "Unexpected dest size "
<< RBI.getSizeInBits(DstReg, MRI, TRI) << '\n');
return false;
}
// A couple helpers below, for making sure that the copy we produce is valid.
// Set to true if we insert a SUBREG_TO_REG. If we do this, then we don't want
// to verify that the src and dst are the same size, since that's handled by
// the SUBREG_TO_REG.
bool KnownValid = false;
// Returns true, or asserts if something we don't expect happens. Instead of
// returning true, we return isValidCopy() to ensure that we verify the
// result.
auto CheckCopy = [&]() {
// If we have a bitcast or something, we can't have physical registers.
assert(
I.isCopy() ||
(!TargetRegisterInfo::isPhysicalRegister(I.getOperand(0).getReg()) &&
!TargetRegisterInfo::isPhysicalRegister(I.getOperand(1).getReg())) &&
"No phys reg on generic operator!");
assert(KnownValid || isValidCopy(I, DstRegBank, MRI, TRI, RBI));
return true;
};
// Is this a copy? If so, then we may need to insert a subregister copy, or
// a SUBREG_TO_REG.
if (I.isCopy()) {
// Yes. Check if there's anything to fix up.
const TargetRegisterClass *SrcRC = getMinClassForRegBank(
SrcRegBank, RBI.getSizeInBits(SrcReg, MRI, TRI), true);
if (!SrcRC) {
LLVM_DEBUG(dbgs() << "Couldn't determine source register class\n");
return false;
}
// Is this a cross-bank copy?
if (DstRegBank.getID() != SrcRegBank.getID()) {
// If we're doing a cross-bank copy on different-sized registers, we need
// to do a bit more work.
unsigned SrcSize = TRI.getRegSizeInBits(*SrcRC);
unsigned DstSize = TRI.getRegSizeInBits(*DstRC);
if (SrcSize > DstSize) {
// We're doing a cross-bank copy into a smaller register. We need a
// subregister copy. First, get a register class that's on the same bank
// as the destination, but the same size as the source.
const TargetRegisterClass *SubregRC =
getMinClassForRegBank(DstRegBank, SrcSize, true);
assert(SubregRC && "Didn't get a register class for subreg?");
// Get the appropriate subregister for the destination.
unsigned SubReg = 0;
if (!getSubRegForClass(DstRC, TRI, SubReg)) {
LLVM_DEBUG(dbgs() << "Couldn't determine subregister for copy.\n");
return false;
}
// Now, insert a subregister copy using the new register class.
selectSubregisterCopy(I, TII, MRI, RBI, SrcReg, SubregRC, DstRC,
SubReg);
return CheckCopy();
}
else if (DstRegBank.getID() == AArch64::GPRRegBankID && DstSize == 32 &&
SrcSize == 16) {
// Special case for FPR16 to GPR32.
// FIXME: This can probably be generalized like the above case.
unsigned PromoteReg =
MRI.createVirtualRegister(&AArch64::FPR32RegClass);
BuildMI(*I.getParent(), I, I.getDebugLoc(),
TII.get(AArch64::SUBREG_TO_REG), PromoteReg)
.addImm(0)
.addUse(SrcReg)
.addImm(AArch64::hsub);
MachineOperand &RegOp = I.getOperand(1);
RegOp.setReg(PromoteReg);
// Promise that the copy is implicitly validated by the SUBREG_TO_REG.
KnownValid = true;
}
}
// If the destination is a physical register, then there's nothing to
// change, so we're done.
if (TargetRegisterInfo::isPhysicalRegister(DstReg))
return CheckCopy();
}
// No need to constrain SrcReg. It will get constrained when we hit another
// of its use or its defs. Copies do not have constraints.
if (!RBI.constrainGenericRegister(DstReg, *DstRC, MRI)) {
LLVM_DEBUG(dbgs() << "Failed to constrain " << TII.getName(I.getOpcode())
<< " operand\n");
return false;
}
I.setDesc(TII.get(AArch64::COPY));
return CheckCopy();
}
static unsigned selectFPConvOpc(unsigned GenericOpc, LLT DstTy, LLT SrcTy) {
if (!DstTy.isScalar() || !SrcTy.isScalar())
return GenericOpc;
const unsigned DstSize = DstTy.getSizeInBits();
const unsigned SrcSize = SrcTy.getSizeInBits();
switch (DstSize) {
case 32:
switch (SrcSize) {
case 32:
switch (GenericOpc) {
case TargetOpcode::G_SITOFP:
return AArch64::SCVTFUWSri;
case TargetOpcode::G_UITOFP:
return AArch64::UCVTFUWSri;
case TargetOpcode::G_FPTOSI:
return AArch64::FCVTZSUWSr;
case TargetOpcode::G_FPTOUI:
return AArch64::FCVTZUUWSr;
default:
return GenericOpc;
}
case 64:
switch (GenericOpc) {
case TargetOpcode::G_SITOFP:
return AArch64::SCVTFUXSri;
case TargetOpcode::G_UITOFP:
return AArch64::UCVTFUXSri;
case TargetOpcode::G_FPTOSI:
return AArch64::FCVTZSUWDr;
case TargetOpcode::G_FPTOUI:
return AArch64::FCVTZUUWDr;
default:
return GenericOpc;
}
default:
return GenericOpc;
}
case 64:
switch (SrcSize) {
case 32:
switch (GenericOpc) {
case TargetOpcode::G_SITOFP:
return AArch64::SCVTFUWDri;
case TargetOpcode::G_UITOFP:
return AArch64::UCVTFUWDri;
case TargetOpcode::G_FPTOSI:
return AArch64::FCVTZSUXSr;
case TargetOpcode::G_FPTOUI:
return AArch64::FCVTZUUXSr;
default:
return GenericOpc;
}
case 64:
switch (GenericOpc) {
case TargetOpcode::G_SITOFP:
return AArch64::SCVTFUXDri;
case TargetOpcode::G_UITOFP:
return AArch64::UCVTFUXDri;
case TargetOpcode::G_FPTOSI:
return AArch64::FCVTZSUXDr;
case TargetOpcode::G_FPTOUI:
return AArch64::FCVTZUUXDr;
default:
return GenericOpc;
}
default:
return GenericOpc;
}
default:
return GenericOpc;
};
return GenericOpc;
}
static AArch64CC::CondCode changeICMPPredToAArch64CC(CmpInst::Predicate P) {
switch (P) {
default:
llvm_unreachable("Unknown condition code!");
case CmpInst::ICMP_NE:
return AArch64CC::NE;
case CmpInst::ICMP_EQ:
return AArch64CC::EQ;
case CmpInst::ICMP_SGT:
return AArch64CC::GT;
case CmpInst::ICMP_SGE:
return AArch64CC::GE;
case CmpInst::ICMP_SLT:
return AArch64CC::LT;
case CmpInst::ICMP_SLE:
return AArch64CC::LE;
case CmpInst::ICMP_UGT:
return AArch64CC::HI;
case CmpInst::ICMP_UGE:
return AArch64CC::HS;
case CmpInst::ICMP_ULT:
return AArch64CC::LO;
case CmpInst::ICMP_ULE:
return AArch64CC::LS;
}
}
static void changeFCMPPredToAArch64CC(CmpInst::Predicate P,
AArch64CC::CondCode &CondCode,
AArch64CC::CondCode &CondCode2) {
CondCode2 = AArch64CC::AL;
switch (P) {
default:
llvm_unreachable("Unknown FP condition!");
case CmpInst::FCMP_OEQ:
CondCode = AArch64CC::EQ;
break;
case CmpInst::FCMP_OGT:
CondCode = AArch64CC::GT;
break;
case CmpInst::FCMP_OGE:
CondCode = AArch64CC::GE;
break;
case CmpInst::FCMP_OLT:
CondCode = AArch64CC::MI;
break;
case CmpInst::FCMP_OLE:
CondCode = AArch64CC::LS;
break;
case CmpInst::FCMP_ONE:
CondCode = AArch64CC::MI;
CondCode2 = AArch64CC::GT;
break;
case CmpInst::FCMP_ORD:
CondCode = AArch64CC::VC;
break;
case CmpInst::FCMP_UNO:
CondCode = AArch64CC::VS;
break;
case CmpInst::FCMP_UEQ:
CondCode = AArch64CC::EQ;
CondCode2 = AArch64CC::VS;
break;
case CmpInst::FCMP_UGT:
CondCode = AArch64CC::HI;
break;
case CmpInst::FCMP_UGE:
CondCode = AArch64CC::PL;
break;
case CmpInst::FCMP_ULT:
CondCode = AArch64CC::LT;
break;
case CmpInst::FCMP_ULE:
CondCode = AArch64CC::LE;
break;
case CmpInst::FCMP_UNE:
CondCode = AArch64CC::NE;
break;
}
}
bool AArch64InstructionSelector::selectCompareBranch(
MachineInstr &I, MachineFunction &MF, MachineRegisterInfo &MRI) const {
const unsigned CondReg = I.getOperand(0).getReg();
MachineBasicBlock *DestMBB = I.getOperand(1).getMBB();
MachineInstr *CCMI = MRI.getVRegDef(CondReg);
if (CCMI->getOpcode() == TargetOpcode::G_TRUNC)
CCMI = MRI.getVRegDef(CCMI->getOperand(1).getReg());
if (CCMI->getOpcode() != TargetOpcode::G_ICMP)
return false;
unsigned LHS = CCMI->getOperand(2).getReg();
unsigned RHS = CCMI->getOperand(3).getReg();
if (!getConstantVRegVal(RHS, MRI))
std::swap(RHS, LHS);
const auto RHSImm = getConstantVRegVal(RHS, MRI);
if (!RHSImm || *RHSImm != 0)
return false;
const RegisterBank &RB = *RBI.getRegBank(LHS, MRI, TRI);
if (RB.getID() != AArch64::GPRRegBankID)
return false;
const auto Pred = (CmpInst::Predicate)CCMI->getOperand(1).getPredicate();
if (Pred != CmpInst::ICMP_NE && Pred != CmpInst::ICMP_EQ)
return false;
const unsigned CmpWidth = MRI.getType(LHS).getSizeInBits();
unsigned CBOpc = 0;
if (CmpWidth <= 32)
CBOpc = (Pred == CmpInst::ICMP_EQ ? AArch64::CBZW : AArch64::CBNZW);
else if (CmpWidth == 64)
CBOpc = (Pred == CmpInst::ICMP_EQ ? AArch64::CBZX : AArch64::CBNZX);
else
return false;
BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(CBOpc))
.addUse(LHS)
.addMBB(DestMBB)
.constrainAllUses(TII, TRI, RBI);
I.eraseFromParent();
return true;
}
bool AArch64InstructionSelector::selectVaStartAAPCS(
MachineInstr &I, MachineFunction &MF, MachineRegisterInfo &MRI) const {
return false;
}
bool AArch64InstructionSelector::selectVaStartDarwin(
MachineInstr &I, MachineFunction &MF, MachineRegisterInfo &MRI) const {
AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
unsigned ListReg = I.getOperand(0).getReg();
unsigned ArgsAddrReg = MRI.createVirtualRegister(&AArch64::GPR64RegClass);
auto MIB =
BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(AArch64::ADDXri))
.addDef(ArgsAddrReg)
.addFrameIndex(FuncInfo->getVarArgsStackIndex())
.addImm(0)
.addImm(0);
constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI);
MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(AArch64::STRXui))
.addUse(ArgsAddrReg)
.addUse(ListReg)
.addImm(0)
.addMemOperand(*I.memoperands_begin());
constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI);
I.eraseFromParent();
return true;
}
void AArch64InstructionSelector::materializeLargeCMVal(
MachineInstr &I, const Value *V, unsigned char OpFlags) const {
MachineBasicBlock &MBB = *I.getParent();
MachineFunction &MF = *MBB.getParent();
MachineRegisterInfo &MRI = MF.getRegInfo();
MachineIRBuilder MIB(I);
auto MovZ = MIB.buildInstr(AArch64::MOVZXi, {&AArch64::GPR64RegClass}, {});
MovZ->addOperand(MF, I.getOperand(1));
MovZ->getOperand(1).setTargetFlags(OpFlags | AArch64II::MO_G0 |
AArch64II::MO_NC);
MovZ->addOperand(MF, MachineOperand::CreateImm(0));
constrainSelectedInstRegOperands(*MovZ, TII, TRI, RBI);
auto BuildMovK = [&](unsigned SrcReg, unsigned char Flags, unsigned Offset,
unsigned ForceDstReg) {
unsigned DstReg = ForceDstReg
? ForceDstReg
: MRI.createVirtualRegister(&AArch64::GPR64RegClass);
auto MovI = MIB.buildInstr(AArch64::MOVKXi).addDef(DstReg).addUse(SrcReg);
if (auto *GV = dyn_cast<GlobalValue>(V)) {
MovI->addOperand(MF, MachineOperand::CreateGA(
GV, MovZ->getOperand(1).getOffset(), Flags));
} else {
MovI->addOperand(
MF, MachineOperand::CreateBA(cast<BlockAddress>(V),
MovZ->getOperand(1).getOffset(), Flags));
}
MovI->addOperand(MF, MachineOperand::CreateImm(Offset));
constrainSelectedInstRegOperands(*MovI, TII, TRI, RBI);
return DstReg;
};
unsigned DstReg = BuildMovK(MovZ->getOperand(0).getReg(),
AArch64II::MO_G1 | AArch64II::MO_NC, 16, 0);
DstReg = BuildMovK(DstReg, AArch64II::MO_G2 | AArch64II::MO_NC, 32, 0);
BuildMovK(DstReg, AArch64II::MO_G3, 48, I.getOperand(0).getReg());
return;
}
bool AArch64InstructionSelector::select(MachineInstr &I,
CodeGenCoverage &CoverageInfo) const {
assert(I.getParent() && "Instruction should be in a basic block!");
assert(I.getParent()->getParent() && "Instruction should be in a function!");
MachineBasicBlock &MBB = *I.getParent();
MachineFunction &MF = *MBB.getParent();
MachineRegisterInfo &MRI = MF.getRegInfo();
unsigned Opcode = I.getOpcode();
// G_PHI requires same handling as PHI
if (!isPreISelGenericOpcode(Opcode) || Opcode == TargetOpcode::G_PHI) {
// Certain non-generic instructions also need some special handling.
if (Opcode == TargetOpcode::LOAD_STACK_GUARD)
return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
if (Opcode == TargetOpcode::PHI || Opcode == TargetOpcode::G_PHI) {
const unsigned DefReg = I.getOperand(0).getReg();
const LLT DefTy = MRI.getType(DefReg);
const TargetRegisterClass *DefRC = nullptr;
if (TargetRegisterInfo::isPhysicalRegister(DefReg)) {
DefRC = TRI.getRegClass(DefReg);
} else {
const RegClassOrRegBank &RegClassOrBank =
MRI.getRegClassOrRegBank(DefReg);
DefRC = RegClassOrBank.dyn_cast<const TargetRegisterClass *>();
if (!DefRC) {
if (!DefTy.isValid()) {
LLVM_DEBUG(dbgs() << "PHI operand has no type, not a gvreg?\n");
return false;
}
const RegisterBank &RB = *RegClassOrBank.get<const RegisterBank *>();
DefRC = getRegClassForTypeOnBank(DefTy, RB, RBI);
if (!DefRC) {
LLVM_DEBUG(dbgs() << "PHI operand has unexpected size/bank\n");
return false;
}
}
}
I.setDesc(TII.get(TargetOpcode::PHI));
return RBI.constrainGenericRegister(DefReg, *DefRC, MRI);
}
if (I.isCopy())
return selectCopy(I, TII, MRI, TRI, RBI);
return true;
}
if (I.getNumOperands() != I.getNumExplicitOperands()) {
LLVM_DEBUG(
dbgs() << "Generic instruction has unexpected implicit operands\n");
return false;
}
if (selectImpl(I, CoverageInfo))
return true;
LLT Ty =
I.getOperand(0).isReg() ? MRI.getType(I.getOperand(0).getReg()) : LLT{};
switch (Opcode) {
case TargetOpcode::G_BRCOND: {
if (Ty.getSizeInBits() > 32) {
// We shouldn't need this on AArch64, but it would be implemented as an
// EXTRACT_SUBREG followed by a TBNZW because TBNZX has no encoding if the
// bit being tested is < 32.
LLVM_DEBUG(dbgs() << "G_BRCOND has type: " << Ty
<< ", expected at most 32-bits");
return false;
}
const unsigned CondReg = I.getOperand(0).getReg();
MachineBasicBlock *DestMBB = I.getOperand(1).getMBB();
// Speculation tracking/SLH assumes that optimized TB(N)Z/CB(N)Z
// instructions will not be produced, as they are conditional branch
// instructions that do not set flags.
bool ProduceNonFlagSettingCondBr =
!MF.getFunction().hasFnAttribute(Attribute::SpeculativeLoadHardening);
if (ProduceNonFlagSettingCondBr && selectCompareBranch(I, MF, MRI))
return true;
if (ProduceNonFlagSettingCondBr) {
auto MIB = BuildMI(MBB, I, I.getDebugLoc(), TII.get(AArch64::TBNZW))
.addUse(CondReg)
.addImm(/*bit offset=*/0)
.addMBB(DestMBB);
I.eraseFromParent();
return constrainSelectedInstRegOperands(*MIB.getInstr(), TII, TRI, RBI);
} else {
auto CMP = BuildMI(MBB, I, I.getDebugLoc(), TII.get(AArch64::ANDSWri))
.addDef(AArch64::WZR)
.addUse(CondReg)
.addImm(1);
constrainSelectedInstRegOperands(*CMP.getInstr(), TII, TRI, RBI);
auto Bcc =
BuildMI(MBB, I, I.getDebugLoc(), TII.get(AArch64::Bcc))
.addImm(AArch64CC::EQ)
.addMBB(DestMBB);
I.eraseFromParent();
return constrainSelectedInstRegOperands(*Bcc.getInstr(), TII, TRI, RBI);
}
}
case TargetOpcode::G_BRINDIRECT: {
I.setDesc(TII.get(AArch64::BR));
return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
}
case TargetOpcode::G_FCONSTANT:
case TargetOpcode::G_CONSTANT: {
const bool isFP = Opcode == TargetOpcode::G_FCONSTANT;
const LLT s32 = LLT::scalar(32);
const LLT s64 = LLT::scalar(64);
const LLT p0 = LLT::pointer(0, 64);
const unsigned DefReg = I.getOperand(0).getReg();
const LLT DefTy = MRI.getType(DefReg);
const unsigned DefSize = DefTy.getSizeInBits();
const RegisterBank &RB = *RBI.getRegBank(DefReg, MRI, TRI);
// FIXME: Redundant check, but even less readable when factored out.
if (isFP) {
if (Ty != s32 && Ty != s64) {
LLVM_DEBUG(dbgs() << "Unable to materialize FP " << Ty
<< " constant, expected: " << s32 << " or " << s64
<< '\n');
return false;
}
if (RB.getID() != AArch64::FPRRegBankID) {
LLVM_DEBUG(dbgs() << "Unable to materialize FP " << Ty
<< " constant on bank: " << RB
<< ", expected: FPR\n");
return false;
}
// The case when we have 0.0 is covered by tablegen. Reject it here so we
// can be sure tablegen works correctly and isn't rescued by this code.
if (I.getOperand(1).getFPImm()->getValueAPF().isExactlyValue(0.0))
return false;
} else {
// s32 and s64 are covered by tablegen.
if (Ty != p0) {
LLVM_DEBUG(dbgs() << "Unable to materialize integer " << Ty
<< " constant, expected: " << s32 << ", " << s64
<< ", or " << p0 << '\n');
return false;
}
if (RB.getID() != AArch64::GPRRegBankID) {
LLVM_DEBUG(dbgs() << "Unable to materialize integer " << Ty
<< " constant on bank: " << RB
<< ", expected: GPR\n");
return false;
}
}
const unsigned MovOpc =
DefSize == 32 ? AArch64::MOVi32imm : AArch64::MOVi64imm;
I.setDesc(TII.get(MovOpc));
if (isFP) {
const TargetRegisterClass &GPRRC =
DefSize == 32 ? AArch64::GPR32RegClass : AArch64::GPR64RegClass;
const TargetRegisterClass &FPRRC =
DefSize == 32 ? AArch64::FPR32RegClass : AArch64::FPR64RegClass;
const unsigned DefGPRReg = MRI.createVirtualRegister(&GPRRC);
MachineOperand &RegOp = I.getOperand(0);
RegOp.setReg(DefGPRReg);
BuildMI(MBB, std::next(I.getIterator()), I.getDebugLoc(),
TII.get(AArch64::COPY))
.addDef(DefReg)
.addUse(DefGPRReg);
if (!RBI.constrainGenericRegister(DefReg, FPRRC, MRI)) {
LLVM_DEBUG(dbgs() << "Failed to constrain G_FCONSTANT def operand\n");
return false;
}
MachineOperand &ImmOp = I.getOperand(1);
// FIXME: Is going through int64_t always correct?
ImmOp.ChangeToImmediate(
ImmOp.getFPImm()->getValueAPF().bitcastToAPInt().getZExtValue());
} else if (I.getOperand(1).isCImm()) {
uint64_t Val = I.getOperand(1).getCImm()->getZExtValue();
I.getOperand(1).ChangeToImmediate(Val);
} else if (I.getOperand(1).isImm()) {
uint64_t Val = I.getOperand(1).getImm();
I.getOperand(1).ChangeToImmediate(Val);
}
constrainSelectedInstRegOperands(I, TII, TRI, RBI);
return true;
}
case TargetOpcode::G_EXTRACT: {
LLT SrcTy = MRI.getType(I.getOperand(1).getReg());
LLT DstTy = MRI.getType(I.getOperand(0).getReg());
(void)DstTy;
unsigned SrcSize = SrcTy.getSizeInBits();
// Larger extracts are vectors, same-size extracts should be something else
// by now (either split up or simplified to a COPY).
if (SrcTy.getSizeInBits() > 64 || Ty.getSizeInBits() > 32)
return false;
I.setDesc(TII.get(SrcSize == 64 ? AArch64::UBFMXri : AArch64::UBFMWri));
MachineInstrBuilder(MF, I).addImm(I.getOperand(2).getImm() +
Ty.getSizeInBits() - 1);
if (SrcSize < 64) {
assert(SrcSize == 32 && DstTy.getSizeInBits() == 16 &&
"unexpected G_EXTRACT types");
return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
}
unsigned DstReg = MRI.createGenericVirtualRegister(LLT::scalar(64));
BuildMI(MBB, std::next(I.getIterator()), I.getDebugLoc(),
TII.get(AArch64::COPY))
.addDef(I.getOperand(0).getReg())
.addUse(DstReg, 0, AArch64::sub_32);
RBI.constrainGenericRegister(I.getOperand(0).getReg(),
AArch64::GPR32RegClass, MRI);
I.getOperand(0).setReg(DstReg);
return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
}
case TargetOpcode::G_INSERT: {
LLT SrcTy = MRI.getType(I.getOperand(2).getReg());
LLT DstTy = MRI.getType(I.getOperand(0).getReg());
unsigned DstSize = DstTy.getSizeInBits();
// Larger inserts are vectors, same-size ones should be something else by
// now (split up or turned into COPYs).
if (Ty.getSizeInBits() > 64 || SrcTy.getSizeInBits() > 32)
return false;
I.setDesc(TII.get(DstSize == 64 ? AArch64::BFMXri : AArch64::BFMWri));
unsigned LSB = I.getOperand(3).getImm();
unsigned Width = MRI.getType(I.getOperand(2).getReg()).getSizeInBits();
I.getOperand(3).setImm((DstSize - LSB) % DstSize);
MachineInstrBuilder(MF, I).addImm(Width - 1);
if (DstSize < 64) {
assert(DstSize == 32 && SrcTy.getSizeInBits() == 16 &&
"unexpected G_INSERT types");
return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
}
unsigned SrcReg = MRI.createGenericVirtualRegister(LLT::scalar(64));
BuildMI(MBB, I.getIterator(), I.getDebugLoc(),
TII.get(AArch64::SUBREG_TO_REG))
.addDef(SrcReg)
.addImm(0)
.addUse(I.getOperand(2).getReg())
.addImm(AArch64::sub_32);
RBI.constrainGenericRegister(I.getOperand(2).getReg(),
AArch64::GPR32RegClass, MRI);
I.getOperand(2).setReg(SrcReg);
return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
}
case TargetOpcode::G_FRAME_INDEX: {
// allocas and G_FRAME_INDEX are only supported in addrspace(0).
if (Ty != LLT::pointer(0, 64)) {
LLVM_DEBUG(dbgs() << "G_FRAME_INDEX pointer has type: " << Ty
<< ", expected: " << LLT::pointer(0, 64) << '\n');
return false;
}
I.setDesc(TII.get(AArch64::ADDXri));
// MOs for a #0 shifted immediate.
I.addOperand(MachineOperand::CreateImm(0));
I.addOperand(MachineOperand::CreateImm(0));
return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
}
case TargetOpcode::G_GLOBAL_VALUE: {
auto GV = I.getOperand(1).getGlobal();
if (GV->isThreadLocal()) {
// FIXME: we don't support TLS yet.
return false;
}
unsigned char OpFlags = STI.ClassifyGlobalReference(GV, TM);
if (OpFlags & AArch64II::MO_GOT) {
I.setDesc(TII.get(AArch64::LOADgot));
I.getOperand(1).setTargetFlags(OpFlags);
} else if (TM.getCodeModel() == CodeModel::Large) {
// Materialize the global using movz/movk instructions.
materializeLargeCMVal(I, GV, OpFlags);
I.eraseFromParent();
return true;
} else if (TM.getCodeModel() == CodeModel::Tiny) {
I.setDesc(TII.get(AArch64::ADR));
I.getOperand(1).setTargetFlags(OpFlags);
} else {
I.setDesc(TII.get(AArch64::MOVaddr));
I.getOperand(1).setTargetFlags(OpFlags | AArch64II::MO_PAGE);
MachineInstrBuilder MIB(MF, I);
MIB.addGlobalAddress(GV, I.getOperand(1).getOffset(),
OpFlags | AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
}
return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
}
case TargetOpcode::G_LOAD:
case TargetOpcode::G_STORE: {
LLT PtrTy = MRI.getType(I.getOperand(1).getReg());
if (PtrTy != LLT::pointer(0, 64)) {
LLVM_DEBUG(dbgs() << "Load/Store pointer has type: " << PtrTy
<< ", expected: " << LLT::pointer(0, 64) << '\n');
return false;
}
auto &MemOp = **I.memoperands_begin();
if (MemOp.getOrdering() != AtomicOrdering::NotAtomic) {
LLVM_DEBUG(dbgs() << "Atomic load/store not supported yet\n");
return false;
}
unsigned MemSizeInBits = MemOp.getSize() * 8;
const unsigned PtrReg = I.getOperand(1).getReg();
#ifndef NDEBUG
const RegisterBank &PtrRB = *RBI.getRegBank(PtrReg, MRI, TRI);
// Sanity-check the pointer register.
assert(PtrRB.getID() == AArch64::GPRRegBankID &&
"Load/Store pointer operand isn't a GPR");
assert(MRI.getType(PtrReg).isPointer() &&
"Load/Store pointer operand isn't a pointer");
#endif
const unsigned ValReg = I.getOperand(0).getReg();
const RegisterBank &RB = *RBI.getRegBank(ValReg, MRI, TRI);
const unsigned NewOpc =
selectLoadStoreUIOp(I.getOpcode(), RB.getID(), MemSizeInBits);
if (NewOpc == I.getOpcode())
return false;
I.setDesc(TII.get(NewOpc));
uint64_t Offset = 0;
auto *PtrMI = MRI.getVRegDef(PtrReg);
// Try to fold a GEP into our unsigned immediate addressing mode.
if (PtrMI->getOpcode() == TargetOpcode::G_GEP) {
if (auto COff = getConstantVRegVal(PtrMI->getOperand(2).getReg(), MRI)) {
int64_t Imm = *COff;
const unsigned Size = MemSizeInBits / 8;
const unsigned Scale = Log2_32(Size);
if ((Imm & (Size - 1)) == 0 && Imm >= 0 && Imm < (0x1000 << Scale)) {
unsigned Ptr2Reg = PtrMI->getOperand(1).getReg();
I.getOperand(1).setReg(Ptr2Reg);
PtrMI = MRI.getVRegDef(Ptr2Reg);
Offset = Imm / Size;
}
}
}
// If we haven't folded anything into our addressing mode yet, try to fold
// a frame index into the base+offset.
if (!Offset && PtrMI->getOpcode() == TargetOpcode::G_FRAME_INDEX)
I.getOperand(1).ChangeToFrameIndex(PtrMI->getOperand(1).getIndex());
I.addOperand(MachineOperand::CreateImm(Offset));
// If we're storing a 0, use WZR/XZR.
if (auto CVal = getConstantVRegVal(ValReg, MRI)) {
if (*CVal == 0 && Opcode == TargetOpcode::G_STORE) {
if (I.getOpcode() == AArch64::STRWui)
I.getOperand(0).setReg(AArch64::WZR);
else if (I.getOpcode() == AArch64::STRXui)
I.getOperand(0).setReg(AArch64::XZR);
}
}
return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
}
case TargetOpcode::G_SMULH:
case TargetOpcode::G_UMULH: {
// Reject the various things we don't support yet.
if (unsupportedBinOp(I, RBI, MRI, TRI))
return false;
const unsigned DefReg = I.getOperand(0).getReg();
const RegisterBank &RB = *RBI.getRegBank(DefReg, MRI, TRI);
if (RB.getID() != AArch64::GPRRegBankID) {
LLVM_DEBUG(dbgs() << "G_[SU]MULH on bank: " << RB << ", expected: GPR\n");
return false;
}
if (Ty != LLT::scalar(64)) {
LLVM_DEBUG(dbgs() << "G_[SU]MULH has type: " << Ty
<< ", expected: " << LLT::scalar(64) << '\n');
return false;
}
unsigned NewOpc = I.getOpcode() == TargetOpcode::G_SMULH ? AArch64::SMULHrr
: AArch64::UMULHrr;
I.setDesc(TII.get(NewOpc));
// Now that we selected an opcode, we need to constrain the register
// operands to use appropriate classes.
return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
}
case TargetOpcode::G_FADD:
case TargetOpcode::G_FSUB:
case TargetOpcode::G_FMUL:
case TargetOpcode::G_FDIV:
case TargetOpcode::G_OR:
case TargetOpcode::G_SHL:
case TargetOpcode::G_LSHR:
case TargetOpcode::G_ASHR:
case TargetOpcode::G_GEP: {
// Reject the various things we don't support yet.
if (unsupportedBinOp(I, RBI, MRI, TRI))
return false;
const unsigned OpSize = Ty.getSizeInBits();
const unsigned DefReg = I.getOperand(0).getReg();
const RegisterBank &RB = *RBI.getRegBank(DefReg, MRI, TRI);
const unsigned NewOpc = selectBinaryOp(I.getOpcode(), RB.getID(), OpSize);
if (NewOpc == I.getOpcode())
return false;
I.setDesc(TII.get(NewOpc));
// FIXME: Should the type be always reset in setDesc?
// Now that we selected an opcode, we need to constrain the register
// operands to use appropriate classes.
return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
}
case TargetOpcode::G_PTR_MASK: {
uint64_t Align = I.getOperand(2).getImm();
if (Align >= 64 || Align == 0)
return false;
uint64_t Mask = ~((1ULL << Align) - 1);
I.setDesc(TII.get(AArch64::ANDXri));
I.getOperand(2).setImm(AArch64_AM::encodeLogicalImmediate(Mask, 64));
return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
}
case TargetOpcode::G_PTRTOINT:
case TargetOpcode::G_TRUNC: {
const LLT DstTy = MRI.getType(I.getOperand(0).getReg());
const LLT SrcTy = MRI.getType(I.getOperand(1).getReg());
const unsigned DstReg = I.getOperand(0).getReg();
const unsigned SrcReg = I.getOperand(1).getReg();
const RegisterBank &DstRB = *RBI.getRegBank(DstReg, MRI, TRI);
const RegisterBank &SrcRB = *RBI.getRegBank(SrcReg, MRI, TRI);
if (DstRB.getID() != SrcRB.getID()) {
LLVM_DEBUG(
dbgs() << "G_TRUNC/G_PTRTOINT input/output on different banks\n");
return false;
}
if (DstRB.getID() == AArch64::GPRRegBankID) {
const TargetRegisterClass *DstRC =
getRegClassForTypeOnBank(DstTy, DstRB, RBI);
if (!DstRC)
return false;
const TargetRegisterClass *SrcRC =
getRegClassForTypeOnBank(SrcTy, SrcRB, RBI);
if (!SrcRC)
return false;
if (!RBI.constrainGenericRegister(SrcReg, *SrcRC, MRI) ||
!RBI.constrainGenericRegister(DstReg, *DstRC, MRI)) {
LLVM_DEBUG(dbgs() << "Failed to constrain G_TRUNC/G_PTRTOINT\n");
return false;
}
if (DstRC == SrcRC) {
// Nothing to be done
} else if (Opcode == TargetOpcode::G_TRUNC && DstTy == LLT::scalar(32) &&
SrcTy == LLT::scalar(64)) {
llvm_unreachable("TableGen can import this case");
return false;
} else if (DstRC == &AArch64::GPR32RegClass &&
SrcRC == &AArch64::GPR64RegClass) {
I.getOperand(1).setSubReg(AArch64::sub_32);
} else {
LLVM_DEBUG(
dbgs() << "Unhandled mismatched classes in G_TRUNC/G_PTRTOINT\n");
return false;
}
I.setDesc(TII.get(TargetOpcode::COPY));
return true;
} else if (DstRB.getID() == AArch64::FPRRegBankID) {
if (DstTy == LLT::vector(4, 16) && SrcTy == LLT::vector(4, 32)) {
I.setDesc(TII.get(AArch64::XTNv4i16));
constrainSelectedInstRegOperands(I, TII, TRI, RBI);
return true;
}
}
return false;
}
case TargetOpcode::G_ANYEXT: {
const unsigned DstReg = I.getOperand(0).getReg();
const unsigned SrcReg = I.getOperand(1).getReg();
const RegisterBank &RBDst = *RBI.getRegBank(DstReg, MRI, TRI);
if (RBDst.getID() != AArch64::GPRRegBankID) {
LLVM_DEBUG(dbgs() << "G_ANYEXT on bank: " << RBDst
<< ", expected: GPR\n");
return false;
}
const RegisterBank &RBSrc = *RBI.getRegBank(SrcReg, MRI, TRI);
if (RBSrc.getID() != AArch64::GPRRegBankID) {
LLVM_DEBUG(dbgs() << "G_ANYEXT on bank: " << RBSrc
<< ", expected: GPR\n");
return false;
}
const unsigned DstSize = MRI.getType(DstReg).getSizeInBits();
if (DstSize == 0) {
LLVM_DEBUG(dbgs() << "G_ANYEXT operand has no size, not a gvreg?\n");
return false;
}
if (DstSize != 64 && DstSize > 32) {
LLVM_DEBUG(dbgs() << "G_ANYEXT to size: " << DstSize
<< ", expected: 32 or 64\n");
return false;
}
// At this point G_ANYEXT is just like a plain COPY, but we need
// to explicitly form the 64-bit value if any.
if (DstSize > 32) {
unsigned ExtSrc = MRI.createVirtualRegister(&AArch64::GPR64allRegClass);
BuildMI(MBB, I, I.getDebugLoc(), TII.get(AArch64::SUBREG_TO_REG))
.addDef(ExtSrc)
.addImm(0)
.addUse(SrcReg)
.addImm(AArch64::sub_32);
I.getOperand(1).setReg(ExtSrc);
}
return selectCopy(I, TII, MRI, TRI, RBI);
}
case TargetOpcode::G_ZEXT:
case TargetOpcode::G_SEXT: {
unsigned Opcode = I.getOpcode();
const LLT DstTy = MRI.getType(I.getOperand(0).getReg()),
SrcTy = MRI.getType(I.getOperand(1).getReg());
const bool isSigned = Opcode == TargetOpcode::G_SEXT;
const unsigned DefReg = I.getOperand(0).getReg();
const unsigned SrcReg = I.getOperand(1).getReg();
const RegisterBank &RB = *RBI.getRegBank(DefReg, MRI, TRI);
if (RB.getID() != AArch64::GPRRegBankID) {
LLVM_DEBUG(dbgs() << TII.getName(I.getOpcode()) << " on bank: " << RB
<< ", expected: GPR\n");
return false;
}
MachineInstr *ExtI;
if (DstTy == LLT::scalar(64)) {
// FIXME: Can we avoid manually doing this?
if (!RBI.constrainGenericRegister(SrcReg, AArch64::GPR32RegClass, MRI)) {
LLVM_DEBUG(dbgs() << "Failed to constrain " << TII.getName(Opcode)
<< " operand\n");
return false;
}
const unsigned SrcXReg =
MRI.createVirtualRegister(&AArch64::GPR64RegClass);
BuildMI(MBB, I, I.getDebugLoc(), TII.get(AArch64::SUBREG_TO_REG))
.addDef(SrcXReg)
.addImm(0)
.addUse(SrcReg)
.addImm(AArch64::sub_32);
const unsigned NewOpc = isSigned ? AArch64::SBFMXri : AArch64::UBFMXri;
ExtI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(NewOpc))
.addDef(DefReg)
.addUse(SrcXReg)
.addImm(0)
.addImm(SrcTy.getSizeInBits() - 1);
} else if (DstTy.isScalar() && DstTy.getSizeInBits() <= 32) {
const unsigned NewOpc = isSigned ? AArch64::SBFMWri : AArch64::UBFMWri;
ExtI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(NewOpc))
.addDef(DefReg)
.addUse(SrcReg)
.addImm(0)
.addImm(SrcTy.getSizeInBits() - 1);
} else {
return false;
}
constrainSelectedInstRegOperands(*ExtI, TII, TRI, RBI);
I.eraseFromParent();
return true;
}
case TargetOpcode::G_SITOFP:
case TargetOpcode::G_UITOFP:
case TargetOpcode::G_FPTOSI:
case TargetOpcode::G_FPTOUI: {
const LLT DstTy = MRI.getType(I.getOperand(0).getReg()),
SrcTy = MRI.getType(I.getOperand(1).getReg());
const unsigned NewOpc = selectFPConvOpc(Opcode, DstTy, SrcTy);
if (NewOpc == Opcode)
return false;
I.setDesc(TII.get(NewOpc));
constrainSelectedInstRegOperands(I, TII, TRI, RBI);
return true;
}
case TargetOpcode::G_INTTOPTR:
// The importer is currently unable to import pointer types since they
// didn't exist in SelectionDAG.
return selectCopy(I, TII, MRI, TRI, RBI);
case TargetOpcode::G_BITCAST:
// Imported SelectionDAG rules can handle every bitcast except those that
// bitcast from a type to the same type. Ideally, these shouldn't occur
// but we might not run an optimizer that deletes them.
if (MRI.getType(I.getOperand(0).getReg()) ==
MRI.getType(I.getOperand(1).getReg()))
return selectCopy(I, TII, MRI, TRI, RBI);
return false;
case TargetOpcode::G_SELECT: {
if (MRI.getType(I.getOperand(1).getReg()) != LLT::scalar(1)) {
LLVM_DEBUG(dbgs() << "G_SELECT cond has type: " << Ty
<< ", expected: " << LLT::scalar(1) << '\n');
return false;
}
const unsigned CondReg = I.getOperand(1).getReg();
const unsigned TReg = I.getOperand(2).getReg();
const unsigned FReg = I.getOperand(3).getReg();
unsigned CSelOpc = 0;
if (Ty == LLT::scalar(32)) {
CSelOpc = AArch64::CSELWr;
} else if (Ty == LLT::scalar(64) || Ty == LLT::pointer(0, 64)) {
CSelOpc = AArch64::CSELXr;
} else {
return false;
}
MachineInstr &TstMI =
*BuildMI(MBB, I, I.getDebugLoc(), TII.get(AArch64::ANDSWri))
.addDef(AArch64::WZR)
.addUse(CondReg)
.addImm(AArch64_AM::encodeLogicalImmediate(1, 32));
MachineInstr &CSelMI = *BuildMI(MBB, I, I.getDebugLoc(), TII.get(CSelOpc))
.addDef(I.getOperand(0).getReg())
.addUse(TReg)
.addUse(FReg)
.addImm(AArch64CC::NE);
constrainSelectedInstRegOperands(TstMI, TII, TRI, RBI);
constrainSelectedInstRegOperands(CSelMI, TII, TRI, RBI);
I.eraseFromParent();
return true;
}
case TargetOpcode::G_ICMP: {
if (Ty != LLT::scalar(32)) {
LLVM_DEBUG(dbgs() << "G_ICMP result has type: " << Ty
<< ", expected: " << LLT::scalar(32) << '\n');
return false;
}
unsigned CmpOpc = 0;
unsigned ZReg = 0;
LLT CmpTy = MRI.getType(I.getOperand(2).getReg());
if (CmpTy == LLT::scalar(32)) {
CmpOpc = AArch64::SUBSWrr;
ZReg = AArch64::WZR;
} else if (CmpTy == LLT::scalar(64) || CmpTy.isPointer()) {
CmpOpc = AArch64::SUBSXrr;
ZReg = AArch64::XZR;
} else {
return false;
}
// CSINC increments the result by one when the condition code is false.
// Therefore, we have to invert the predicate to get an increment by 1 when
// the predicate is true.
const AArch64CC::CondCode invCC =
changeICMPPredToAArch64CC(CmpInst::getInversePredicate(
(CmpInst::Predicate)I.getOperand(1).getPredicate()));
MachineInstr &CmpMI = *BuildMI(MBB, I, I.getDebugLoc(), TII.get(CmpOpc))
.addDef(ZReg)
.addUse(I.getOperand(2).getReg())
.addUse(I.getOperand(3).getReg());
MachineInstr &CSetMI =
*BuildMI(MBB, I, I.getDebugLoc(), TII.get(AArch64::CSINCWr))
.addDef(I.getOperand(0).getReg())
.addUse(AArch64::WZR)
.addUse(AArch64::WZR)
.addImm(invCC);
constrainSelectedInstRegOperands(CmpMI, TII, TRI, RBI);
constrainSelectedInstRegOperands(CSetMI, TII, TRI, RBI);
I.eraseFromParent();
return true;
}
case TargetOpcode::G_FCMP: {
if (Ty != LLT::scalar(32)) {
LLVM_DEBUG(dbgs() << "G_FCMP result has type: " << Ty
<< ", expected: " << LLT::scalar(32) << '\n');
return false;
}
unsigned CmpOpc = 0;
LLT CmpTy = MRI.getType(I.getOperand(2).getReg());
if (CmpTy == LLT::scalar(32)) {
CmpOpc = AArch64::FCMPSrr;
} else if (CmpTy == LLT::scalar(64)) {
CmpOpc = AArch64::FCMPDrr;
} else {
return false;
}
// FIXME: regbank
AArch64CC::CondCode CC1, CC2;
changeFCMPPredToAArch64CC(
(CmpInst::Predicate)I.getOperand(1).getPredicate(), CC1, CC2);
MachineInstr &CmpMI = *BuildMI(MBB, I, I.getDebugLoc(), TII.get(CmpOpc))
.addUse(I.getOperand(2).getReg())
.addUse(I.getOperand(3).getReg());
const unsigned DefReg = I.getOperand(0).getReg();
unsigned Def1Reg = DefReg;
if (CC2 != AArch64CC::AL)
Def1Reg = MRI.createVirtualRegister(&AArch64::GPR32RegClass);
MachineInstr &CSetMI =
*BuildMI(MBB, I, I.getDebugLoc(), TII.get(AArch64::CSINCWr))
.addDef(Def1Reg)
.addUse(AArch64::WZR)
.addUse(AArch64::WZR)
.addImm(getInvertedCondCode(CC1));
if (CC2 != AArch64CC::AL) {
unsigned Def2Reg = MRI.createVirtualRegister(&AArch64::GPR32RegClass);
MachineInstr &CSet2MI =
*BuildMI(MBB, I, I.getDebugLoc(), TII.get(AArch64::CSINCWr))
.addDef(Def2Reg)
.addUse(AArch64::WZR)
.addUse(AArch64::WZR)
.addImm(getInvertedCondCode(CC2));
MachineInstr &OrMI =
*BuildMI(MBB, I, I.getDebugLoc(), TII.get(AArch64::ORRWrr))
.addDef(DefReg)
.addUse(Def1Reg)
.addUse(Def2Reg);
constrainSelectedInstRegOperands(OrMI, TII, TRI, RBI);
constrainSelectedInstRegOperands(CSet2MI, TII, TRI, RBI);
}
constrainSelectedInstRegOperands(CmpMI, TII, TRI, RBI);
constrainSelectedInstRegOperands(CSetMI, TII, TRI, RBI);
I.eraseFromParent();
return true;
}
case TargetOpcode::G_VASTART:
return STI.isTargetDarwin() ? selectVaStartDarwin(I, MF, MRI)
: selectVaStartAAPCS(I, MF, MRI);
case TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS:
if (!I.getOperand(0).isIntrinsicID())
return false;
if (I.getOperand(0).getIntrinsicID() != Intrinsic::trap)
return false;
BuildMI(MBB, I, I.getDebugLoc(), TII.get(AArch64::BRK))
.addImm(1);
I.eraseFromParent();
return true;
case TargetOpcode::G_IMPLICIT_DEF: {
I.setDesc(TII.get(TargetOpcode::IMPLICIT_DEF));
const LLT DstTy = MRI.getType(I.getOperand(0).getReg());
const unsigned DstReg = I.getOperand(0).getReg();
const RegisterBank &DstRB = *RBI.getRegBank(DstReg, MRI, TRI);
const TargetRegisterClass *DstRC =
getRegClassForTypeOnBank(DstTy, DstRB, RBI);
RBI.constrainGenericRegister(DstReg, *DstRC, MRI);
return true;
}
case TargetOpcode::G_BLOCK_ADDR: {
if (TM.getCodeModel() == CodeModel::Large) {
materializeLargeCMVal(I, I.getOperand(1).getBlockAddress(), 0);
I.eraseFromParent();
return true;
} else {
I.setDesc(TII.get(AArch64::MOVaddrBA));
auto MovMI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(AArch64::MOVaddrBA),
I.getOperand(0).getReg())
.addBlockAddress(I.getOperand(1).getBlockAddress(),
/* Offset */ 0, AArch64II::MO_PAGE)
.addBlockAddress(
I.getOperand(1).getBlockAddress(), /* Offset */ 0,
AArch64II::MO_NC | AArch64II::MO_PAGEOFF);
I.eraseFromParent();
return constrainSelectedInstRegOperands(*MovMI, TII, TRI, RBI);
}
}
case TargetOpcode::G_BUILD_VECTOR:
return selectBuildVector(I, MRI);
case TargetOpcode::G_MERGE_VALUES:
return selectMergeValues(I, MRI);
case TargetOpcode::G_UNMERGE_VALUES:
return selectUnmergeValues(I, MRI);
}
return false;
}
bool AArch64InstructionSelector::emitScalarToVector(
unsigned &Dst, const LLT DstTy, const TargetRegisterClass *DstRC,
unsigned Scalar, MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI, MachineRegisterInfo &MRI) const {
Dst = MRI.createVirtualRegister(DstRC);
unsigned UndefVec = MRI.createVirtualRegister(DstRC);
MachineInstr &UndefMI = *BuildMI(MBB, MBBI, MBBI->getDebugLoc(),
TII.get(TargetOpcode::IMPLICIT_DEF))
.addDef(UndefVec);
auto BuildFn = [&](unsigned SubregIndex) {
MachineInstr &InsMI = *BuildMI(MBB, MBBI, MBBI->getDebugLoc(),
TII.get(TargetOpcode::INSERT_SUBREG))
.addDef(Dst)
.addUse(UndefVec)
.addUse(Scalar)
.addImm(SubregIndex);
constrainSelectedInstRegOperands(UndefMI, TII, TRI, RBI);
return constrainSelectedInstRegOperands(InsMI, TII, TRI, RBI);
};
switch (DstTy.getElementType().getSizeInBits()) {
case 16:
return BuildFn(AArch64::hsub);
case 32:
return BuildFn(AArch64::ssub);
case 64:
return BuildFn(AArch64::dsub);
default:
return false;
}
}
bool AArch64InstructionSelector::selectMergeValues(
MachineInstr &I, MachineRegisterInfo &MRI) const {
assert(I.getOpcode() == TargetOpcode::G_MERGE_VALUES && "unexpected opcode");
const LLT DstTy = MRI.getType(I.getOperand(0).getReg());
const LLT SrcTy = MRI.getType(I.getOperand(1).getReg());
assert(!DstTy.isVector() && !SrcTy.isVector() && "invalid merge operation");
// At the moment we only support merging two s32s into an s64.
if (I.getNumOperands() != 3)
return false;
if (DstTy.getSizeInBits() != 64 || SrcTy.getSizeInBits() != 32)
return false;
const RegisterBank &RB = *RBI.getRegBank(I.getOperand(1).getReg(), MRI, TRI);
if (RB.getID() != AArch64::GPRRegBankID)
return false;
auto *DstRC = &AArch64::GPR64RegClass;
unsigned SubToRegDef = MRI.createVirtualRegister(DstRC);
MachineInstr &SubRegMI = *BuildMI(*I.getParent(), I, I.getDebugLoc(),
TII.get(TargetOpcode::SUBREG_TO_REG))
.addDef(SubToRegDef)
.addImm(0)
.addUse(I.getOperand(1).getReg())
.addImm(AArch64::sub_32);
unsigned SubToRegDef2 = MRI.createVirtualRegister(DstRC);
// Need to anyext the second scalar before we can use bfm
MachineInstr &SubRegMI2 = *BuildMI(*I.getParent(), I, I.getDebugLoc(),
TII.get(TargetOpcode::SUBREG_TO_REG))
.addDef(SubToRegDef2)
.addImm(0)
.addUse(I.getOperand(2).getReg())
.addImm(AArch64::sub_32);
MachineInstr &BFM =
*BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(AArch64::BFMXri))
.addDef(I.getOperand(0).getReg())
.addUse(SubToRegDef)
.addUse(SubToRegDef2)
.addImm(32)
.addImm(31);
constrainSelectedInstRegOperands(SubRegMI, TII, TRI, RBI);
constrainSelectedInstRegOperands(SubRegMI2, TII, TRI, RBI);
constrainSelectedInstRegOperands(BFM, TII, TRI, RBI);
I.eraseFromParent();
return true;
}
bool AArch64InstructionSelector::selectUnmergeValues(
MachineInstr &I, MachineRegisterInfo &MRI) const {
assert(I.getOpcode() == TargetOpcode::G_UNMERGE_VALUES &&
"unexpected opcode");
// TODO: Handle unmerging into GPRs and from scalars to scalars.
if (RBI.getRegBank(I.getOperand(0).getReg(), MRI, TRI)->getID() !=
AArch64::FPRRegBankID ||
RBI.getRegBank(I.getOperand(1).getReg(), MRI, TRI)->getID() !=
AArch64::FPRRegBankID) {
LLVM_DEBUG(dbgs() << "Unmerging vector-to-gpr and scalar-to-scalar "
"currently unsupported.\n");
return false;
}
// The last operand is the vector source register, and every other operand is
// a register to unpack into.
unsigned NumElts = I.getNumOperands() - 1;
unsigned SrcReg = I.getOperand(NumElts).getReg();
const LLT NarrowTy = MRI.getType(I.getOperand(0).getReg());
const LLT WideTy = MRI.getType(SrcReg);
(void)WideTy;
assert(WideTy.isVector() && "can only unmerge from vector types!");
assert(WideTy.getSizeInBits() > NarrowTy.getSizeInBits() &&
"source register size too small!");
// TODO: Handle unmerging into scalars.
if (!NarrowTy.isScalar()) {
LLVM_DEBUG(dbgs() << "Vector-to-vector unmerges not supported yet.\n");
return false;
}
// Choose a lane copy opcode and subregister based off of the size of the
// vector's elements.
unsigned CopyOpc = 0;
unsigned ExtractSubReg = 0;
switch (NarrowTy.getSizeInBits()) {
case 16:
CopyOpc = AArch64::CPYi16;
ExtractSubReg = AArch64::hsub;
break;
case 32:
CopyOpc = AArch64::CPYi32;
ExtractSubReg = AArch64::ssub;
break;
case 64:
CopyOpc = AArch64::CPYi64;
ExtractSubReg = AArch64::dsub;
break;
default:
// Unknown size, bail out.
LLVM_DEBUG(dbgs() << "NarrowTy had unsupported size.\n");
return false;
}
// Set up for the lane copies.
MachineBasicBlock &MBB = *I.getParent();
// Stores the registers we'll be copying from.
SmallVector<unsigned, 4> InsertRegs;
// We'll use the first register twice, so we only need NumElts-1 registers.
unsigned NumInsertRegs = NumElts - 1;
// If our elements fit into exactly 128 bits, then we can copy from the source
// directly. Otherwise, we need to do a bit of setup with some subregister
// inserts.
if (NarrowTy.getSizeInBits() * NumElts == 128) {
InsertRegs = SmallVector<unsigned, 4>(NumInsertRegs, SrcReg);
} else {
// No. We have to perform subregister inserts. For each insert, create an
// implicit def and a subregister insert, and save the register we create.
for (unsigned Idx = 0; Idx < NumInsertRegs; ++Idx) {
unsigned ImpDefReg = MRI.createVirtualRegister(&AArch64::FPR128RegClass);
MachineInstr &ImpDefMI =
*BuildMI(MBB, I, I.getDebugLoc(), TII.get(TargetOpcode::IMPLICIT_DEF),
ImpDefReg);
// Now, create the subregister insert from SrcReg.
unsigned InsertReg = MRI.createVirtualRegister(&AArch64::FPR128RegClass);
MachineInstr &InsMI =
*BuildMI(MBB, I, I.getDebugLoc(),
TII.get(TargetOpcode::INSERT_SUBREG), InsertReg)
.addUse(ImpDefReg)
.addUse(SrcReg)
.addImm(AArch64::dsub);
constrainSelectedInstRegOperands(ImpDefMI, TII, TRI, RBI);
constrainSelectedInstRegOperands(InsMI, TII, TRI, RBI);
// Save the register so that we can copy from it after.
InsertRegs.push_back(InsertReg);
}
}
// Now that we've created any necessary subregister inserts, we can
// create the copies.
//
// Perform the first copy separately as a subregister copy.
unsigned CopyTo = I.getOperand(0).getReg();
MachineInstr &FirstCopy =
*BuildMI(MBB, I, I.getDebugLoc(), TII.get(TargetOpcode::COPY), CopyTo)
.addUse(InsertRegs[0], 0, ExtractSubReg);
constrainSelectedInstRegOperands(FirstCopy, TII, TRI, RBI);
// Now, perform the remaining copies as vector lane copies.
unsigned LaneIdx = 1;
for (unsigned InsReg : InsertRegs) {
unsigned CopyTo = I.getOperand(LaneIdx).getReg();
MachineInstr &CopyInst =
*BuildMI(MBB, I, I.getDebugLoc(), TII.get(CopyOpc), CopyTo)
.addUse(InsReg)
.addImm(LaneIdx);
constrainSelectedInstRegOperands(CopyInst, TII, TRI, RBI);
++LaneIdx;
}
// Separately constrain the first copy's destination. Because of the
// limitation in constrainOperandRegClass, we can't guarantee that this will
// actually be constrained. So, do it ourselves using the second operand.
const TargetRegisterClass *RC =
MRI.getRegClassOrNull(I.getOperand(1).getReg());
if (!RC) {
LLVM_DEBUG(dbgs() << "Couldn't constrain copy destination.\n");
return false;
}
RBI.constrainGenericRegister(CopyTo, *RC, MRI);
I.eraseFromParent();
return true;
}
bool AArch64InstructionSelector::selectBuildVector(
MachineInstr &I, MachineRegisterInfo &MRI) const {
assert(I.getOpcode() == TargetOpcode::G_BUILD_VECTOR);
// Until we port more of the optimized selections, for now just use a vector
// insert sequence.
const LLT DstTy = MRI.getType(I.getOperand(0).getReg());
const LLT EltTy = MRI.getType(I.getOperand(1).getReg());
unsigned EltSize = EltTy.getSizeInBits();
if (EltSize < 16 || EltSize > 64)
return false; // Don't support all element types yet.
const RegisterBank &RB = *RBI.getRegBank(I.getOperand(1).getReg(), MRI, TRI);
unsigned Opc;
unsigned SubregIdx;
if (RB.getID() == AArch64::GPRRegBankID) {
if (EltSize == 32) {
Opc = AArch64::INSvi32gpr;
SubregIdx = AArch64::ssub;
} else {
Opc = AArch64::INSvi64gpr;
SubregIdx = AArch64::dsub;
}
} else {
if (EltSize == 16) {
Opc = AArch64::INSvi16lane;
SubregIdx = AArch64::hsub;
} else if (EltSize == 32) {
Opc = AArch64::INSvi32lane;
SubregIdx = AArch64::ssub;
} else {
Opc = AArch64::INSvi64lane;
SubregIdx = AArch64::dsub;
}
}
unsigned DstVec = 0;
const TargetRegisterClass *DstRC = &AArch64::FPR128RegClass;
if (!emitScalarToVector(DstVec, DstTy, DstRC, I.getOperand(1).getReg(),
*I.getParent(), I.getIterator(), MRI))
return false;
unsigned DstSize = DstTy.getSizeInBits();
// Keep track of the last MI we inserted. Later on, we might be able to save
// a copy using it.
MachineInstr *PrevMI = nullptr;
for (unsigned i = 2, e = DstSize / EltSize + 1; i < e; ++i) {
unsigned InsDef;
// Note that if we don't do a subregister copy, we end up making one more
// of these than we need.
InsDef = MRI.createVirtualRegister(DstRC);
unsigned LaneIdx = i - 1;
if (RB.getID() == AArch64::FPRRegBankID) {
unsigned ImpDef = MRI.createVirtualRegister(DstRC);
MachineInstr &ImpDefMI = *BuildMI(*I.getParent(), I, I.getDebugLoc(),
TII.get(TargetOpcode::IMPLICIT_DEF))
.addDef(ImpDef);
unsigned InsSubDef = MRI.createVirtualRegister(DstRC);
MachineInstr &InsSubMI = *BuildMI(*I.getParent(), I, I.getDebugLoc(),
TII.get(TargetOpcode::INSERT_SUBREG))
.addDef(InsSubDef)
.addUse(ImpDef)
.addUse(I.getOperand(i).getReg())
.addImm(SubregIdx);
MachineInstr &InsEltMI =
*BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opc))
.addDef(InsDef)
.addUse(DstVec)
.addImm(LaneIdx)
.addUse(InsSubDef)
.addImm(0);
constrainSelectedInstRegOperands(ImpDefMI, TII, TRI, RBI);
constrainSelectedInstRegOperands(InsSubMI, TII, TRI, RBI);
constrainSelectedInstRegOperands(InsEltMI, TII, TRI, RBI);
DstVec = InsDef;
PrevMI = &InsEltMI;
} else {
MachineInstr &InsMI =
*BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opc))
.addDef(InsDef)
.addUse(DstVec)
.addImm(LaneIdx)
.addUse(I.getOperand(i).getReg());
constrainSelectedInstRegOperands(InsMI, TII, TRI, RBI);
DstVec = InsDef;
PrevMI = &InsMI;
}
}
// If DstTy's size in bits is less than 128, then emit a subregister copy
// from DstVec to the last register we've defined.
if (DstSize < 128) {
unsigned SubReg = 0;
// Helper lambda to decide on a register class and subregister for the
// subregister copy.
auto GetRegInfoForCopy = [&SubReg,
&DstSize]() -> const TargetRegisterClass * {
switch (DstSize) {
default:
LLVM_DEBUG(dbgs() << "Unknown destination size (" << DstSize << ")\n");
return nullptr;
case 32:
SubReg = AArch64::ssub;
return &AArch64::FPR32RegClass;
case 64:
SubReg = AArch64::dsub;
return &AArch64::FPR64RegClass;
}
};
const TargetRegisterClass *RC = GetRegInfoForCopy();
if (!RC)
return false;
unsigned Reg = MRI.createVirtualRegister(RC);
unsigned DstReg = I.getOperand(0).getReg();
BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(TargetOpcode::COPY),
DstReg)
.addUse(DstVec, 0, SubReg);
MachineOperand &RegOp = I.getOperand(1);
RegOp.setReg(Reg);
RBI.constrainGenericRegister(DstReg, *RC, MRI);
} else {
// We don't need a subregister copy. Save a copy by re-using the
// destination register on the final insert.
assert(PrevMI && "PrevMI was null?");
PrevMI->getOperand(0).setReg(I.getOperand(0).getReg());
constrainSelectedInstRegOperands(*PrevMI, TII, TRI, RBI);
}
I.eraseFromParent();
return true;
}
/// SelectArithImmed - Select an immediate value that can be represented as
/// a 12-bit value shifted left by either 0 or 12. If so, return true with
/// Val set to the 12-bit value and Shift set to the shifter operand.
InstructionSelector::ComplexRendererFns
AArch64InstructionSelector::selectArithImmed(MachineOperand &Root) const {
MachineInstr &MI = *Root.getParent();
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
MachineRegisterInfo &MRI = MF.getRegInfo();
// This function is called from the addsub_shifted_imm ComplexPattern,
// which lists [imm] as the list of opcode it's interested in, however
// we still need to check whether the operand is actually an immediate
// here because the ComplexPattern opcode list is only used in
// root-level opcode matching.
uint64_t Immed;
if (Root.isImm())
Immed = Root.getImm();
else if (Root.isCImm())
Immed = Root.getCImm()->getZExtValue();
else if (Root.isReg()) {
MachineInstr *Def = MRI.getVRegDef(Root.getReg());
if (Def->getOpcode() != TargetOpcode::G_CONSTANT)
return None;
MachineOperand &Op1 = Def->getOperand(1);
if (!Op1.isCImm() || Op1.getCImm()->getBitWidth() > 64)
return None;
Immed = Op1.getCImm()->getZExtValue();
} else
return None;
unsigned ShiftAmt;
if (Immed >> 12 == 0) {
ShiftAmt = 0;
} else if ((Immed & 0xfff) == 0 && Immed >> 24 == 0) {
ShiftAmt = 12;
Immed = Immed >> 12;
} else
return None;
unsigned ShVal = AArch64_AM::getShifterImm(AArch64_AM::LSL, ShiftAmt);
return {{
[=](MachineInstrBuilder &MIB) { MIB.addImm(Immed); },
[=](MachineInstrBuilder &MIB) { MIB.addImm(ShVal); },
}};
}
/// Select a "register plus unscaled signed 9-bit immediate" address. This
/// should only match when there is an offset that is not valid for a scaled
/// immediate addressing mode. The "Size" argument is the size in bytes of the
/// memory reference, which is needed here to know what is valid for a scaled
/// immediate.
InstructionSelector::ComplexRendererFns
AArch64InstructionSelector::selectAddrModeUnscaled(MachineOperand &Root,
unsigned Size) const {
MachineRegisterInfo &MRI =
Root.getParent()->getParent()->getParent()->getRegInfo();
if (!Root.isReg())
return None;
if (!isBaseWithConstantOffset(Root, MRI))
return None;
MachineInstr *RootDef = MRI.getVRegDef(Root.getReg());
if (!RootDef)
return None;
MachineOperand &OffImm = RootDef->getOperand(2);
if (!OffImm.isReg())
return None;
MachineInstr *RHS = MRI.getVRegDef(OffImm.getReg());
if (!RHS || RHS->getOpcode() != TargetOpcode::G_CONSTANT)
return None;
int64_t RHSC;
MachineOperand &RHSOp1 = RHS->getOperand(1);
if (!RHSOp1.isCImm() || RHSOp1.getCImm()->getBitWidth() > 64)
return None;
RHSC = RHSOp1.getCImm()->getSExtValue();
// If the offset is valid as a scaled immediate, don't match here.
if ((RHSC & (Size - 1)) == 0 && RHSC >= 0 && RHSC < (0x1000 << Log2_32(Size)))
return None;
if (RHSC >= -256 && RHSC < 256) {
MachineOperand &Base = RootDef->getOperand(1);
return {{
[=](MachineInstrBuilder &MIB) { MIB.add(Base); },
[=](MachineInstrBuilder &MIB) { MIB.addImm(RHSC); },
}};
}
return None;
}
/// Select a "register plus scaled unsigned 12-bit immediate" address. The
/// "Size" argument is the size in bytes of the memory reference, which
/// determines the scale.
InstructionSelector::ComplexRendererFns
AArch64InstructionSelector::selectAddrModeIndexed(MachineOperand &Root,
unsigned Size) const {
MachineRegisterInfo &MRI =
Root.getParent()->getParent()->getParent()->getRegInfo();
if (!Root.isReg())
return None;
MachineInstr *RootDef = MRI.getVRegDef(Root.getReg());
if (!RootDef)
return None;
if (RootDef->getOpcode() == TargetOpcode::G_FRAME_INDEX) {
return {{
[=](MachineInstrBuilder &MIB) { MIB.add(RootDef->getOperand(1)); },
[=](MachineInstrBuilder &MIB) { MIB.addImm(0); },
}};
}
if (isBaseWithConstantOffset(Root, MRI)) {
MachineOperand &LHS = RootDef->getOperand(1);
MachineOperand &RHS = RootDef->getOperand(2);
MachineInstr *LHSDef = MRI.getVRegDef(LHS.getReg());
MachineInstr *RHSDef = MRI.getVRegDef(RHS.getReg());
if (LHSDef && RHSDef) {
int64_t RHSC = (int64_t)RHSDef->getOperand(1).getCImm()->getZExtValue();
unsigned Scale = Log2_32(Size);
if ((RHSC & (Size - 1)) == 0 && RHSC >= 0 && RHSC < (0x1000 << Scale)) {
if (LHSDef->getOpcode() == TargetOpcode::G_FRAME_INDEX)
return {{
[=](MachineInstrBuilder &MIB) { MIB.add(LHSDef->getOperand(1)); },
[=](MachineInstrBuilder &MIB) { MIB.addImm(RHSC >> Scale); },
}};
return {{
[=](MachineInstrBuilder &MIB) { MIB.add(LHS); },
[=](MachineInstrBuilder &MIB) { MIB.addImm(RHSC >> Scale); },
}};
}
}
}
// Before falling back to our general case, check if the unscaled
// instructions can handle this. If so, that's preferable.
if (selectAddrModeUnscaled(Root, Size).hasValue())
return None;
return {{
[=](MachineInstrBuilder &MIB) { MIB.add(Root); },
[=](MachineInstrBuilder &MIB) { MIB.addImm(0); },
}};
}
void AArch64InstructionSelector::renderTruncImm(MachineInstrBuilder &MIB,
const MachineInstr &MI) const {
const MachineRegisterInfo &MRI = MI.getParent()->getParent()->getRegInfo();
assert(MI.getOpcode() == TargetOpcode::G_CONSTANT && "Expected G_CONSTANT");
Optional<int64_t> CstVal = getConstantVRegVal(MI.getOperand(0).getReg(), MRI);
assert(CstVal && "Expected constant value");
MIB.addImm(CstVal.getValue());
}
namespace llvm {
InstructionSelector *
createAArch64InstructionSelector(const AArch64TargetMachine &TM,
AArch64Subtarget &Subtarget,
AArch64RegisterBankInfo &RBI) {
return new AArch64InstructionSelector(TM, Subtarget, RBI);
}
}
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