llvm-project/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp

461 lines
18 KiB
C++

//===- ARMLegalizerInfo.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 Machinelegalizer class for ARM.
/// \todo This should be generated by TableGen.
//===----------------------------------------------------------------------===//
#include "ARMLegalizerInfo.h"
#include "ARMCallLowering.h"
#include "ARMSubtarget.h"
#include "llvm/CodeGen/GlobalISel/LegalizerHelper.h"
#include "llvm/CodeGen/LowLevelType.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/TargetOpcodes.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Type.h"
using namespace llvm;
using namespace LegalizeActions;
/// FIXME: The following static functions are SizeChangeStrategy functions
/// that are meant to temporarily mimic the behaviour of the old legalization
/// based on doubling/halving non-legal types as closely as possible. This is
/// not entirly possible as only legalizing the types that are exactly a power
/// of 2 times the size of the legal types would require specifying all those
/// sizes explicitly.
/// In practice, not specifying those isn't a problem, and the below functions
/// should disappear quickly as we add support for legalizing non-power-of-2
/// sized types further.
static void
addAndInterleaveWithUnsupported(LegalizerInfo::SizeAndActionsVec &result,
const LegalizerInfo::SizeAndActionsVec &v) {
for (unsigned i = 0; i < v.size(); ++i) {
result.push_back(v[i]);
if (i + 1 < v[i].first && i + 1 < v.size() &&
v[i + 1].first != v[i].first + 1)
result.push_back({v[i].first + 1, Unsupported});
}
}
static LegalizerInfo::SizeAndActionsVec
widen_8_16(const LegalizerInfo::SizeAndActionsVec &v) {
assert(v.size() >= 1);
assert(v[0].first > 17);
LegalizerInfo::SizeAndActionsVec result = {{1, Unsupported},
{8, WidenScalar},
{9, Unsupported},
{16, WidenScalar},
{17, Unsupported}};
addAndInterleaveWithUnsupported(result, v);
auto Largest = result.back().first;
result.push_back({Largest + 1, Unsupported});
return result;
}
static bool AEABI(const ARMSubtarget &ST) {
return ST.isTargetAEABI() || ST.isTargetGNUAEABI() || ST.isTargetMuslAEABI();
}
ARMLegalizerInfo::ARMLegalizerInfo(const ARMSubtarget &ST) {
using namespace TargetOpcode;
const LLT p0 = LLT::pointer(0, 32);
const LLT s1 = LLT::scalar(1);
const LLT s8 = LLT::scalar(8);
const LLT s16 = LLT::scalar(16);
const LLT s32 = LLT::scalar(32);
const LLT s64 = LLT::scalar(64);
if (ST.isThumb1Only()) {
// Thumb1 is not supported yet.
computeTables();
verify(*ST.getInstrInfo());
return;
}
getActionDefinitionsBuilder({G_SEXT, G_ZEXT, G_ANYEXT})
.legalForCartesianProduct({s32}, {s1, s8, s16});
getActionDefinitionsBuilder({G_ADD, G_SUB, G_MUL, G_AND, G_OR, G_XOR})
.legalFor({s32})
.minScalar(0, s32);
getActionDefinitionsBuilder({G_ASHR, G_LSHR, G_SHL})
.legalFor({{s32, s32}})
.clampScalar(1, s32, s32);
bool HasHWDivide = (!ST.isThumb() && ST.hasDivideInARMMode()) ||
(ST.isThumb() && ST.hasDivideInThumbMode());
if (HasHWDivide)
getActionDefinitionsBuilder({G_SDIV, G_UDIV})
.legalFor({s32})
.clampScalar(0, s32, s32);
else
getActionDefinitionsBuilder({G_SDIV, G_UDIV})
.libcallFor({s32})
.clampScalar(0, s32, s32);
for (unsigned Op : {G_SREM, G_UREM}) {
setLegalizeScalarToDifferentSizeStrategy(Op, 0, widen_8_16);
if (HasHWDivide)
setAction({Op, s32}, Lower);
else if (AEABI(ST))
setAction({Op, s32}, Custom);
else
setAction({Op, s32}, Libcall);
}
getActionDefinitionsBuilder(G_INTTOPTR).legalFor({{p0, s32}});
getActionDefinitionsBuilder(G_PTRTOINT).legalFor({{s32, p0}});
getActionDefinitionsBuilder(G_CONSTANT)
.legalFor({s32, p0})
.clampScalar(0, s32, s32);
getActionDefinitionsBuilder(G_ICMP)
.legalForCartesianProduct({s1}, {s32, p0})
.minScalar(1, s32);
getActionDefinitionsBuilder(G_SELECT).legalForCartesianProduct({s32, p0},
{s1});
// We're keeping these builders around because we'll want to add support for
// floating point to them.
auto &LoadStoreBuilder =
getActionDefinitionsBuilder({G_LOAD, G_STORE})
.legalForTypesWithMemDesc({
{s1, p0, 8, 8},
{s8, p0, 8, 8},
{s16, p0, 16, 8},
{s32, p0, 32, 8},
{p0, p0, 32, 8}});
getActionDefinitionsBuilder(G_FRAME_INDEX).legalFor({p0});
getActionDefinitionsBuilder(G_GLOBAL_VALUE).legalFor({p0});
auto &PhiBuilder =
getActionDefinitionsBuilder(G_PHI)
.legalFor({s32, p0})
.minScalar(0, s32);
getActionDefinitionsBuilder(G_GEP).legalFor({{p0, s32}});
getActionDefinitionsBuilder(G_BRCOND).legalFor({s1});
if (!ST.useSoftFloat() && ST.hasVFP2()) {
getActionDefinitionsBuilder(
{G_FADD, G_FSUB, G_FMUL, G_FDIV, G_FCONSTANT, G_FNEG})
.legalFor({s32, s64});
LoadStoreBuilder.legalFor({{s64, p0}});
PhiBuilder.legalFor({s64});
getActionDefinitionsBuilder(G_FCMP).legalForCartesianProduct({s1},
{s32, s64});
getActionDefinitionsBuilder(G_MERGE_VALUES).legalFor({{s64, s32}});
getActionDefinitionsBuilder(G_UNMERGE_VALUES).legalFor({{s32, s64}});
getActionDefinitionsBuilder(G_FPEXT).legalFor({{s64, s32}});
getActionDefinitionsBuilder(G_FPTRUNC).legalFor({{s32, s64}});
getActionDefinitionsBuilder({G_FPTOSI, G_FPTOUI})
.legalForCartesianProduct({s32}, {s32, s64});
getActionDefinitionsBuilder({G_SITOFP, G_UITOFP})
.legalForCartesianProduct({s32, s64}, {s32});
} else {
getActionDefinitionsBuilder({G_FADD, G_FSUB, G_FMUL, G_FDIV})
.libcallFor({s32, s64});
LoadStoreBuilder.maxScalar(0, s32);
for (auto Ty : {s32, s64})
setAction({G_FNEG, Ty}, Lower);
getActionDefinitionsBuilder(G_FCONSTANT).customFor({s32, s64});
getActionDefinitionsBuilder(G_FCMP).customForCartesianProduct({s1},
{s32, s64});
if (AEABI(ST))
setFCmpLibcallsAEABI();
else
setFCmpLibcallsGNU();
getActionDefinitionsBuilder(G_FPEXT).libcallFor({{s64, s32}});
getActionDefinitionsBuilder(G_FPTRUNC).libcallFor({{s32, s64}});
getActionDefinitionsBuilder({G_FPTOSI, G_FPTOUI})
.libcallForCartesianProduct({s32}, {s32, s64});
getActionDefinitionsBuilder({G_SITOFP, G_UITOFP})
.libcallForCartesianProduct({s32, s64}, {s32});
}
if (!ST.useSoftFloat() && ST.hasVFP4())
getActionDefinitionsBuilder(G_FMA).legalFor({s32, s64});
else
getActionDefinitionsBuilder(G_FMA).libcallFor({s32, s64});
getActionDefinitionsBuilder({G_FREM, G_FPOW}).libcallFor({s32, s64});
if (ST.hasV5TOps()) {
getActionDefinitionsBuilder(G_CTLZ)
.legalFor({s32, s32})
.clampScalar(1, s32, s32)
.clampScalar(0, s32, s32);
getActionDefinitionsBuilder(G_CTLZ_ZERO_UNDEF)
.lowerFor({s32, s32})
.clampScalar(1, s32, s32)
.clampScalar(0, s32, s32);
} else {
getActionDefinitionsBuilder(G_CTLZ_ZERO_UNDEF)
.libcallFor({s32, s32})
.clampScalar(1, s32, s32)
.clampScalar(0, s32, s32);
getActionDefinitionsBuilder(G_CTLZ)
.lowerFor({s32, s32})
.clampScalar(1, s32, s32)
.clampScalar(0, s32, s32);
}
computeTables();
verify(*ST.getInstrInfo());
}
void ARMLegalizerInfo::setFCmpLibcallsAEABI() {
// FCMP_TRUE and FCMP_FALSE don't need libcalls, they should be
// default-initialized.
FCmp32Libcalls.resize(CmpInst::LAST_FCMP_PREDICATE + 1);
FCmp32Libcalls[CmpInst::FCMP_OEQ] = {
{RTLIB::OEQ_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp32Libcalls[CmpInst::FCMP_OGE] = {
{RTLIB::OGE_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp32Libcalls[CmpInst::FCMP_OGT] = {
{RTLIB::OGT_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp32Libcalls[CmpInst::FCMP_OLE] = {
{RTLIB::OLE_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp32Libcalls[CmpInst::FCMP_OLT] = {
{RTLIB::OLT_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp32Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::O_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_UGE] = {{RTLIB::OLT_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_UGT] = {{RTLIB::OLE_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_ULE] = {{RTLIB::OGT_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_ULT] = {{RTLIB::OGE_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_UNE] = {{RTLIB::UNE_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_UNO] = {
{RTLIB::UO_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp32Libcalls[CmpInst::FCMP_ONE] = {
{RTLIB::OGT_F32, CmpInst::BAD_ICMP_PREDICATE},
{RTLIB::OLT_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp32Libcalls[CmpInst::FCMP_UEQ] = {
{RTLIB::OEQ_F32, CmpInst::BAD_ICMP_PREDICATE},
{RTLIB::UO_F32, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls.resize(CmpInst::LAST_FCMP_PREDICATE + 1);
FCmp64Libcalls[CmpInst::FCMP_OEQ] = {
{RTLIB::OEQ_F64, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls[CmpInst::FCMP_OGE] = {
{RTLIB::OGE_F64, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls[CmpInst::FCMP_OGT] = {
{RTLIB::OGT_F64, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls[CmpInst::FCMP_OLE] = {
{RTLIB::OLE_F64, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls[CmpInst::FCMP_OLT] = {
{RTLIB::OLT_F64, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::O_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_UGE] = {{RTLIB::OLT_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_UGT] = {{RTLIB::OLE_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_ULE] = {{RTLIB::OGT_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_ULT] = {{RTLIB::OGE_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_UNE] = {{RTLIB::UNE_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_UNO] = {
{RTLIB::UO_F64, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls[CmpInst::FCMP_ONE] = {
{RTLIB::OGT_F64, CmpInst::BAD_ICMP_PREDICATE},
{RTLIB::OLT_F64, CmpInst::BAD_ICMP_PREDICATE}};
FCmp64Libcalls[CmpInst::FCMP_UEQ] = {
{RTLIB::OEQ_F64, CmpInst::BAD_ICMP_PREDICATE},
{RTLIB::UO_F64, CmpInst::BAD_ICMP_PREDICATE}};
}
void ARMLegalizerInfo::setFCmpLibcallsGNU() {
// FCMP_TRUE and FCMP_FALSE don't need libcalls, they should be
// default-initialized.
FCmp32Libcalls.resize(CmpInst::LAST_FCMP_PREDICATE + 1);
FCmp32Libcalls[CmpInst::FCMP_OEQ] = {{RTLIB::OEQ_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_OGE] = {{RTLIB::OGE_F32, CmpInst::ICMP_SGE}};
FCmp32Libcalls[CmpInst::FCMP_OGT] = {{RTLIB::OGT_F32, CmpInst::ICMP_SGT}};
FCmp32Libcalls[CmpInst::FCMP_OLE] = {{RTLIB::OLE_F32, CmpInst::ICMP_SLE}};
FCmp32Libcalls[CmpInst::FCMP_OLT] = {{RTLIB::OLT_F32, CmpInst::ICMP_SLT}};
FCmp32Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::O_F32, CmpInst::ICMP_EQ}};
FCmp32Libcalls[CmpInst::FCMP_UGE] = {{RTLIB::OLT_F32, CmpInst::ICMP_SGE}};
FCmp32Libcalls[CmpInst::FCMP_UGT] = {{RTLIB::OLE_F32, CmpInst::ICMP_SGT}};
FCmp32Libcalls[CmpInst::FCMP_ULE] = {{RTLIB::OGT_F32, CmpInst::ICMP_SLE}};
FCmp32Libcalls[CmpInst::FCMP_ULT] = {{RTLIB::OGE_F32, CmpInst::ICMP_SLT}};
FCmp32Libcalls[CmpInst::FCMP_UNE] = {{RTLIB::UNE_F32, CmpInst::ICMP_NE}};
FCmp32Libcalls[CmpInst::FCMP_UNO] = {{RTLIB::UO_F32, CmpInst::ICMP_NE}};
FCmp32Libcalls[CmpInst::FCMP_ONE] = {{RTLIB::OGT_F32, CmpInst::ICMP_SGT},
{RTLIB::OLT_F32, CmpInst::ICMP_SLT}};
FCmp32Libcalls[CmpInst::FCMP_UEQ] = {{RTLIB::OEQ_F32, CmpInst::ICMP_EQ},
{RTLIB::UO_F32, CmpInst::ICMP_NE}};
FCmp64Libcalls.resize(CmpInst::LAST_FCMP_PREDICATE + 1);
FCmp64Libcalls[CmpInst::FCMP_OEQ] = {{RTLIB::OEQ_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_OGE] = {{RTLIB::OGE_F64, CmpInst::ICMP_SGE}};
FCmp64Libcalls[CmpInst::FCMP_OGT] = {{RTLIB::OGT_F64, CmpInst::ICMP_SGT}};
FCmp64Libcalls[CmpInst::FCMP_OLE] = {{RTLIB::OLE_F64, CmpInst::ICMP_SLE}};
FCmp64Libcalls[CmpInst::FCMP_OLT] = {{RTLIB::OLT_F64, CmpInst::ICMP_SLT}};
FCmp64Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::O_F64, CmpInst::ICMP_EQ}};
FCmp64Libcalls[CmpInst::FCMP_UGE] = {{RTLIB::OLT_F64, CmpInst::ICMP_SGE}};
FCmp64Libcalls[CmpInst::FCMP_UGT] = {{RTLIB::OLE_F64, CmpInst::ICMP_SGT}};
FCmp64Libcalls[CmpInst::FCMP_ULE] = {{RTLIB::OGT_F64, CmpInst::ICMP_SLE}};
FCmp64Libcalls[CmpInst::FCMP_ULT] = {{RTLIB::OGE_F64, CmpInst::ICMP_SLT}};
FCmp64Libcalls[CmpInst::FCMP_UNE] = {{RTLIB::UNE_F64, CmpInst::ICMP_NE}};
FCmp64Libcalls[CmpInst::FCMP_UNO] = {{RTLIB::UO_F64, CmpInst::ICMP_NE}};
FCmp64Libcalls[CmpInst::FCMP_ONE] = {{RTLIB::OGT_F64, CmpInst::ICMP_SGT},
{RTLIB::OLT_F64, CmpInst::ICMP_SLT}};
FCmp64Libcalls[CmpInst::FCMP_UEQ] = {{RTLIB::OEQ_F64, CmpInst::ICMP_EQ},
{RTLIB::UO_F64, CmpInst::ICMP_NE}};
}
ARMLegalizerInfo::FCmpLibcallsList
ARMLegalizerInfo::getFCmpLibcalls(CmpInst::Predicate Predicate,
unsigned Size) const {
assert(CmpInst::isFPPredicate(Predicate) && "Unsupported FCmp predicate");
if (Size == 32)
return FCmp32Libcalls[Predicate];
if (Size == 64)
return FCmp64Libcalls[Predicate];
llvm_unreachable("Unsupported size for FCmp predicate");
}
bool ARMLegalizerInfo::legalizeCustom(MachineInstr &MI,
MachineRegisterInfo &MRI,
MachineIRBuilder &MIRBuilder,
GISelChangeObserver &Observer) const {
using namespace TargetOpcode;
MIRBuilder.setInstr(MI);
LLVMContext &Ctx = MIRBuilder.getMF().getFunction().getContext();
switch (MI.getOpcode()) {
default:
return false;
case G_SREM:
case G_UREM: {
unsigned OriginalResult = MI.getOperand(0).getReg();
auto Size = MRI.getType(OriginalResult).getSizeInBits();
if (Size != 32)
return false;
auto Libcall =
MI.getOpcode() == G_SREM ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32;
// Our divmod libcalls return a struct containing the quotient and the
// remainder. We need to create a virtual register for it.
Type *ArgTy = Type::getInt32Ty(Ctx);
StructType *RetTy = StructType::get(Ctx, {ArgTy, ArgTy}, /* Packed */ true);
auto RetVal = MRI.createGenericVirtualRegister(
getLLTForType(*RetTy, MIRBuilder.getMF().getDataLayout()));
auto Status = createLibcall(MIRBuilder, Libcall, {RetVal, RetTy},
{{MI.getOperand(1).getReg(), ArgTy},
{MI.getOperand(2).getReg(), ArgTy}});
if (Status != LegalizerHelper::Legalized)
return false;
// The remainder is the second result of divmod. Split the return value into
// a new, unused register for the quotient and the destination of the
// original instruction for the remainder.
MIRBuilder.buildUnmerge(
{MRI.createGenericVirtualRegister(LLT::scalar(32)), OriginalResult},
RetVal);
break;
}
case G_FCMP: {
assert(MRI.getType(MI.getOperand(2).getReg()) ==
MRI.getType(MI.getOperand(3).getReg()) &&
"Mismatched operands for G_FCMP");
auto OpSize = MRI.getType(MI.getOperand(2).getReg()).getSizeInBits();
auto OriginalResult = MI.getOperand(0).getReg();
auto Predicate =
static_cast<CmpInst::Predicate>(MI.getOperand(1).getPredicate());
auto Libcalls = getFCmpLibcalls(Predicate, OpSize);
if (Libcalls.empty()) {
assert((Predicate == CmpInst::FCMP_TRUE ||
Predicate == CmpInst::FCMP_FALSE) &&
"Predicate needs libcalls, but none specified");
MIRBuilder.buildConstant(OriginalResult,
Predicate == CmpInst::FCMP_TRUE ? 1 : 0);
MI.eraseFromParent();
return true;
}
assert((OpSize == 32 || OpSize == 64) && "Unsupported operand size");
auto *ArgTy = OpSize == 32 ? Type::getFloatTy(Ctx) : Type::getDoubleTy(Ctx);
auto *RetTy = Type::getInt32Ty(Ctx);
SmallVector<unsigned, 2> Results;
for (auto Libcall : Libcalls) {
auto LibcallResult = MRI.createGenericVirtualRegister(LLT::scalar(32));
auto Status =
createLibcall(MIRBuilder, Libcall.LibcallID, {LibcallResult, RetTy},
{{MI.getOperand(2).getReg(), ArgTy},
{MI.getOperand(3).getReg(), ArgTy}});
if (Status != LegalizerHelper::Legalized)
return false;
auto ProcessedResult =
Libcalls.size() == 1
? OriginalResult
: MRI.createGenericVirtualRegister(MRI.getType(OriginalResult));
// We have a result, but we need to transform it into a proper 1-bit 0 or
// 1, taking into account the different peculiarities of the values
// returned by the comparison functions.
CmpInst::Predicate ResultPred = Libcall.Predicate;
if (ResultPred == CmpInst::BAD_ICMP_PREDICATE) {
// We have a nice 0 or 1, and we just need to truncate it back to 1 bit
// to keep the types consistent.
MIRBuilder.buildTrunc(ProcessedResult, LibcallResult);
} else {
// We need to compare against 0.
assert(CmpInst::isIntPredicate(ResultPred) && "Unsupported predicate");
auto Zero = MRI.createGenericVirtualRegister(LLT::scalar(32));
MIRBuilder.buildConstant(Zero, 0);
MIRBuilder.buildICmp(ResultPred, ProcessedResult, LibcallResult, Zero);
}
Results.push_back(ProcessedResult);
}
if (Results.size() != 1) {
assert(Results.size() == 2 && "Unexpected number of results");
MIRBuilder.buildOr(OriginalResult, Results[0], Results[1]);
}
break;
}
case G_FCONSTANT: {
// Convert to integer constants, while preserving the binary representation.
auto AsInteger =
MI.getOperand(1).getFPImm()->getValueAPF().bitcastToAPInt();
MIRBuilder.buildConstant(MI.getOperand(0).getReg(),
*ConstantInt::get(Ctx, AsInteger));
break;
}
}
MI.eraseFromParent();
return true;
}