blob: 61c562852f2d363a7dc9b29dae58dbc05aa1d5cc [file] [log] [blame]
//===- TargetLoweringBase.cpp - Implement the TargetLoweringBase class ----===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This implements the TargetLoweringBase class.
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Triple.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Analysis/Loads.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/ISDOpcodes.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RuntimeLibcalls.h"
#include "llvm/CodeGen/StackMaps.h"
#include "llvm/CodeGen/TargetLowering.h"
#include "llvm/CodeGen/TargetOpcodes.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
#include "llvm/Support/BranchProbability.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MachineValueType.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Transforms/Utils/SizeOpts.h"
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <cstring>
#include <iterator>
#include <string>
#include <tuple>
#include <utility>
using namespace llvm;
static cl::opt<bool> JumpIsExpensiveOverride(
"jump-is-expensive", cl::init(false),
cl::desc("Do not create extra branches to split comparison logic."),
static cl::opt<unsigned> MinimumJumpTableEntries
("min-jump-table-entries", cl::init(4), cl::Hidden,
cl::desc("Set minimum number of entries to use a jump table."));
static cl::opt<unsigned> MaximumJumpTableSize
("max-jump-table-size", cl::init(UINT_MAX), cl::Hidden,
cl::desc("Set maximum size of jump tables."));
/// Minimum jump table density for normal functions.
static cl::opt<unsigned>
JumpTableDensity("jump-table-density", cl::init(10), cl::Hidden,
cl::desc("Minimum density for building a jump table in "
"a normal function"));
/// Minimum jump table density for -Os or -Oz functions.
static cl::opt<unsigned> OptsizeJumpTableDensity(
"optsize-jump-table-density", cl::init(40), cl::Hidden,
cl::desc("Minimum density for building a jump table in "
"an optsize function"));
// FIXME: This option is only to test if the strict fp operation processed
// correctly by preventing mutating strict fp operation to normal fp operation
// during development. When the backend supports strict float operation, this
// option will be meaningless.
static cl::opt<bool> DisableStrictNodeMutation("disable-strictnode-mutation",
cl::desc("Don't mutate strict-float node to a legalize node"),
cl::init(false), cl::Hidden);
static bool darwinHasSinCos(const Triple &TT) {
assert(TT.isOSDarwin() && "should be called with darwin triple");
// Don't bother with 32 bit x86.
if (TT.getArch() == Triple::x86)
return false;
// Macos < 10.9 has no sincos_stret.
if (TT.isMacOSX())
return !TT.isMacOSXVersionLT(10, 9) && TT.isArch64Bit();
// iOS < 7.0 has no sincos_stret.
if (TT.isiOS())
return !TT.isOSVersionLT(7, 0);
// Any other darwin such as WatchOS/TvOS is new enough.
return true;
// Although this default value is arbitrary, it is not random. It is assumed
// that a condition that evaluates the same way by a higher percentage than this
// is best represented as control flow. Therefore, the default value N should be
// set such that the win from N% correct executions is greater than the loss
// from (100 - N)% mispredicted executions for the majority of intended targets.
static cl::opt<int> MinPercentageForPredictableBranch(
"min-predictable-branch", cl::init(99),
cl::desc("Minimum percentage (0-100) that a condition must be either true "
"or false to assume that the condition is predictable"),
void TargetLoweringBase::InitLibcalls(const Triple &TT) {
#define HANDLE_LIBCALL(code, name) \
setLibcallName(RTLIB::code, name);
#include "llvm/IR/RuntimeLibcalls.def"
// Initialize calling conventions to their default.
for (int LC = 0; LC < RTLIB::UNKNOWN_LIBCALL; ++LC)
setLibcallCallingConv((RTLIB::Libcall)LC, CallingConv::C);
// For IEEE quad-precision libcall names, PPC uses "kf" instead of "tf".
if (TT.isPPC()) {
setLibcallName(RTLIB::ADD_F128, "__addkf3");
setLibcallName(RTLIB::SUB_F128, "__subkf3");
setLibcallName(RTLIB::MUL_F128, "__mulkf3");
setLibcallName(RTLIB::DIV_F128, "__divkf3");
setLibcallName(RTLIB::POWI_F128, "__powikf2");
setLibcallName(RTLIB::FPEXT_F32_F128, "__extendsfkf2");
setLibcallName(RTLIB::FPEXT_F64_F128, "__extenddfkf2");
setLibcallName(RTLIB::FPROUND_F128_F32, "__trunckfsf2");
setLibcallName(RTLIB::FPROUND_F128_F64, "__trunckfdf2");
setLibcallName(RTLIB::FPTOSINT_F128_I32, "__fixkfsi");
setLibcallName(RTLIB::FPTOSINT_F128_I64, "__fixkfdi");
setLibcallName(RTLIB::FPTOSINT_F128_I128, "__fixkfti");
setLibcallName(RTLIB::FPTOUINT_F128_I32, "__fixunskfsi");
setLibcallName(RTLIB::FPTOUINT_F128_I64, "__fixunskfdi");
setLibcallName(RTLIB::FPTOUINT_F128_I128, "__fixunskfti");
setLibcallName(RTLIB::SINTTOFP_I32_F128, "__floatsikf");
setLibcallName(RTLIB::SINTTOFP_I64_F128, "__floatdikf");
setLibcallName(RTLIB::SINTTOFP_I128_F128, "__floattikf");
setLibcallName(RTLIB::UINTTOFP_I32_F128, "__floatunsikf");
setLibcallName(RTLIB::UINTTOFP_I64_F128, "__floatundikf");
setLibcallName(RTLIB::UINTTOFP_I128_F128, "__floatuntikf");
setLibcallName(RTLIB::OEQ_F128, "__eqkf2");
setLibcallName(RTLIB::UNE_F128, "__nekf2");
setLibcallName(RTLIB::OGE_F128, "__gekf2");
setLibcallName(RTLIB::OLT_F128, "__ltkf2");
setLibcallName(RTLIB::OLE_F128, "__lekf2");
setLibcallName(RTLIB::OGT_F128, "__gtkf2");
setLibcallName(RTLIB::UO_F128, "__unordkf2");
// A few names are different on particular architectures or environments.
if (TT.isOSDarwin()) {
// For f16/f32 conversions, Darwin uses the standard naming scheme, instead
// of the gnueabi-style __gnu_*_ieee.
// FIXME: What about other targets?
setLibcallName(RTLIB::FPEXT_F16_F32, "__extendhfsf2");
setLibcallName(RTLIB::FPROUND_F32_F16, "__truncsfhf2");
// Some darwins have an optimized __bzero/bzero function.
switch (TT.getArch()) {
case Triple::x86:
case Triple::x86_64:
if (TT.isMacOSX() && !TT.isMacOSXVersionLT(10, 6))
setLibcallName(RTLIB::BZERO, "__bzero");
case Triple::aarch64:
case Triple::aarch64_32:
setLibcallName(RTLIB::BZERO, "bzero");
if (darwinHasSinCos(TT)) {
setLibcallName(RTLIB::SINCOS_STRET_F32, "__sincosf_stret");
setLibcallName(RTLIB::SINCOS_STRET_F64, "__sincos_stret");
if (TT.isWatchABI()) {
} else {
setLibcallName(RTLIB::FPEXT_F16_F32, "__gnu_h2f_ieee");
setLibcallName(RTLIB::FPROUND_F32_F16, "__gnu_f2h_ieee");
if (TT.isGNUEnvironment() || TT.isOSFuchsia() ||
(TT.isAndroid() && !TT.isAndroidVersionLT(9))) {
setLibcallName(RTLIB::SINCOS_F32, "sincosf");
setLibcallName(RTLIB::SINCOS_F64, "sincos");
setLibcallName(RTLIB::SINCOS_F80, "sincosl");
setLibcallName(RTLIB::SINCOS_F128, "sincosl");
setLibcallName(RTLIB::SINCOS_PPCF128, "sincosl");
if (TT.isPS4CPU()) {
setLibcallName(RTLIB::SINCOS_F32, "sincosf");
setLibcallName(RTLIB::SINCOS_F64, "sincos");
if (TT.isOSOpenBSD()) {
/// getFPEXT - Return the FPEXT_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
if (OpVT == MVT::f16) {
if (RetVT == MVT::f32)
return FPEXT_F16_F32;
if (RetVT == MVT::f64)
return FPEXT_F16_F64;
if (RetVT == MVT::f128)
return FPEXT_F16_F128;
} else if (OpVT == MVT::f32) {
if (RetVT == MVT::f64)
return FPEXT_F32_F64;
if (RetVT == MVT::f128)
return FPEXT_F32_F128;
if (RetVT == MVT::ppcf128)
return FPEXT_F32_PPCF128;
} else if (OpVT == MVT::f64) {
if (RetVT == MVT::f128)
return FPEXT_F64_F128;
else if (RetVT == MVT::ppcf128)
return FPEXT_F64_PPCF128;
} else if (OpVT == MVT::f80) {
if (RetVT == MVT::f128)
return FPEXT_F80_F128;
/// getFPROUND - Return the FPROUND_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
if (RetVT == MVT::f16) {
if (OpVT == MVT::f32)
return FPROUND_F32_F16;
if (OpVT == MVT::f64)
return FPROUND_F64_F16;
if (OpVT == MVT::f80)
return FPROUND_F80_F16;
if (OpVT == MVT::f128)
return FPROUND_F128_F16;
if (OpVT == MVT::ppcf128)
return FPROUND_PPCF128_F16;
} else if (RetVT == MVT::f32) {
if (OpVT == MVT::f64)
return FPROUND_F64_F32;
if (OpVT == MVT::f80)
return FPROUND_F80_F32;
if (OpVT == MVT::f128)
return FPROUND_F128_F32;
if (OpVT == MVT::ppcf128)
return FPROUND_PPCF128_F32;
} else if (RetVT == MVT::f64) {
if (OpVT == MVT::f80)
return FPROUND_F80_F64;
if (OpVT == MVT::f128)
return FPROUND_F128_F64;
if (OpVT == MVT::ppcf128)
return FPROUND_PPCF128_F64;
} else if (RetVT == MVT::f80) {
if (OpVT == MVT::f128)
return FPROUND_F128_F80;
/// getFPTOSINT - Return the FPTOSINT_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
if (OpVT == MVT::f16) {
if (RetVT == MVT::i32)
return FPTOSINT_F16_I32;
if (RetVT == MVT::i64)
return FPTOSINT_F16_I64;
if (RetVT == MVT::i128)
return FPTOSINT_F16_I128;
} else if (OpVT == MVT::f32) {
if (RetVT == MVT::i32)
return FPTOSINT_F32_I32;
if (RetVT == MVT::i64)
return FPTOSINT_F32_I64;
if (RetVT == MVT::i128)
return FPTOSINT_F32_I128;
} else if (OpVT == MVT::f64) {
if (RetVT == MVT::i32)
return FPTOSINT_F64_I32;
if (RetVT == MVT::i64)
return FPTOSINT_F64_I64;
if (RetVT == MVT::i128)
return FPTOSINT_F64_I128;
} else if (OpVT == MVT::f80) {
if (RetVT == MVT::i32)
return FPTOSINT_F80_I32;
if (RetVT == MVT::i64)
return FPTOSINT_F80_I64;
if (RetVT == MVT::i128)
return FPTOSINT_F80_I128;
} else if (OpVT == MVT::f128) {
if (RetVT == MVT::i32)
return FPTOSINT_F128_I32;
if (RetVT == MVT::i64)
return FPTOSINT_F128_I64;
if (RetVT == MVT::i128)
return FPTOSINT_F128_I128;
} else if (OpVT == MVT::ppcf128) {
if (RetVT == MVT::i32)
return FPTOSINT_PPCF128_I32;
if (RetVT == MVT::i64)
return FPTOSINT_PPCF128_I64;
if (RetVT == MVT::i128)
return FPTOSINT_PPCF128_I128;
/// getFPTOUINT - Return the FPTOUINT_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
if (OpVT == MVT::f16) {
if (RetVT == MVT::i32)
return FPTOUINT_F16_I32;
if (RetVT == MVT::i64)
return FPTOUINT_F16_I64;
if (RetVT == MVT::i128)
return FPTOUINT_F16_I128;
} else if (OpVT == MVT::f32) {
if (RetVT == MVT::i32)
return FPTOUINT_F32_I32;
if (RetVT == MVT::i64)
return FPTOUINT_F32_I64;
if (RetVT == MVT::i128)
return FPTOUINT_F32_I128;
} else if (OpVT == MVT::f64) {
if (RetVT == MVT::i32)
return FPTOUINT_F64_I32;
if (RetVT == MVT::i64)
return FPTOUINT_F64_I64;
if (RetVT == MVT::i128)
return FPTOUINT_F64_I128;
} else if (OpVT == MVT::f80) {
if (RetVT == MVT::i32)
return FPTOUINT_F80_I32;
if (RetVT == MVT::i64)
return FPTOUINT_F80_I64;
if (RetVT == MVT::i128)
return FPTOUINT_F80_I128;
} else if (OpVT == MVT::f128) {
if (RetVT == MVT::i32)
return FPTOUINT_F128_I32;
if (RetVT == MVT::i64)
return FPTOUINT_F128_I64;
if (RetVT == MVT::i128)
return FPTOUINT_F128_I128;
} else if (OpVT == MVT::ppcf128) {
if (RetVT == MVT::i32)
return FPTOUINT_PPCF128_I32;
if (RetVT == MVT::i64)
return FPTOUINT_PPCF128_I64;
if (RetVT == MVT::i128)
return FPTOUINT_PPCF128_I128;
/// getSINTTOFP - Return the SINTTOFP_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
if (OpVT == MVT::i32) {
if (RetVT == MVT::f16)
return SINTTOFP_I32_F16;
if (RetVT == MVT::f32)
return SINTTOFP_I32_F32;
if (RetVT == MVT::f64)
return SINTTOFP_I32_F64;
if (RetVT == MVT::f80)
return SINTTOFP_I32_F80;
if (RetVT == MVT::f128)
return SINTTOFP_I32_F128;
if (RetVT == MVT::ppcf128)
return SINTTOFP_I32_PPCF128;
} else if (OpVT == MVT::i64) {
if (RetVT == MVT::f16)
return SINTTOFP_I64_F16;
if (RetVT == MVT::f32)
return SINTTOFP_I64_F32;
if (RetVT == MVT::f64)
return SINTTOFP_I64_F64;
if (RetVT == MVT::f80)
return SINTTOFP_I64_F80;
if (RetVT == MVT::f128)
return SINTTOFP_I64_F128;
if (RetVT == MVT::ppcf128)
return SINTTOFP_I64_PPCF128;
} else if (OpVT == MVT::i128) {
if (RetVT == MVT::f16)
return SINTTOFP_I128_F16;
if (RetVT == MVT::f32)
return SINTTOFP_I128_F32;
if (RetVT == MVT::f64)
return SINTTOFP_I128_F64;
if (RetVT == MVT::f80)
return SINTTOFP_I128_F80;
if (RetVT == MVT::f128)
return SINTTOFP_I128_F128;
if (RetVT == MVT::ppcf128)
return SINTTOFP_I128_PPCF128;
/// getUINTTOFP - Return the UINTTOFP_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
if (OpVT == MVT::i32) {
if (RetVT == MVT::f16)
return UINTTOFP_I32_F16;
if (RetVT == MVT::f32)
return UINTTOFP_I32_F32;
if (RetVT == MVT::f64)
return UINTTOFP_I32_F64;
if (RetVT == MVT::f80)
return UINTTOFP_I32_F80;
if (RetVT == MVT::f128)
return UINTTOFP_I32_F128;
if (RetVT == MVT::ppcf128)
return UINTTOFP_I32_PPCF128;
} else if (OpVT == MVT::i64) {
if (RetVT == MVT::f16)
return UINTTOFP_I64_F16;
if (RetVT == MVT::f32)
return UINTTOFP_I64_F32;
if (RetVT == MVT::f64)
return UINTTOFP_I64_F64;
if (RetVT == MVT::f80)
return UINTTOFP_I64_F80;
if (RetVT == MVT::f128)
return UINTTOFP_I64_F128;
if (RetVT == MVT::ppcf128)
return UINTTOFP_I64_PPCF128;
} else if (OpVT == MVT::i128) {
if (RetVT == MVT::f16)
return UINTTOFP_I128_F16;
if (RetVT == MVT::f32)
return UINTTOFP_I128_F32;
if (RetVT == MVT::f64)
return UINTTOFP_I128_F64;
if (RetVT == MVT::f80)
return UINTTOFP_I128_F80;
if (RetVT == MVT::f128)
return UINTTOFP_I128_F128;
if (RetVT == MVT::ppcf128)
return UINTTOFP_I128_PPCF128;
RTLIB::Libcall RTLIB::getOUTLINE_ATOMIC(unsigned Opc, AtomicOrdering Order,
unsigned ModeN, ModelN;
switch (VT.SimpleTy) {
case MVT::i8:
ModeN = 0;
case MVT::i16:
ModeN = 1;
case MVT::i32:
ModeN = 2;
case MVT::i64:
ModeN = 3;
case MVT::i128:
ModeN = 4;
switch (Order) {
case AtomicOrdering::Monotonic:
ModelN = 0;
case AtomicOrdering::Acquire:
ModelN = 1;
case AtomicOrdering::Release:
ModelN = 2;
case AtomicOrdering::AcquireRelease:
case AtomicOrdering::SequentiallyConsistent:
ModelN = 3;
#define LCALLS(A, B) \
{ A##B##_RELAX, A##B##_ACQ, A##B##_REL, A##B##_ACQ_REL }
#define LCALL5(A) \
switch (Opc) {
const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_CAS)};
return LC[ModeN][ModelN];
const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_SWP)};
return LC[ModeN][ModelN];
const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDADD)};
return LC[ModeN][ModelN];
const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDSET)};
return LC[ModeN][ModelN];
const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDCLR)};
return LC[ModeN][ModelN];
const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDEOR)};
return LC[ModeN][ModelN];
#undef LCALLS
#undef LCALL5
RTLIB::Libcall RTLIB::getSYNC(unsigned Opc, MVT VT) {
#define OP_TO_LIBCALL(Name, Enum) \
case Name: \
switch (VT.SimpleTy) { \
default: \
case MVT::i8: \
return Enum##_1; \
case MVT::i16: \
return Enum##_2; \
case MVT::i32: \
return Enum##_4; \
case MVT::i64: \
return Enum##_8; \
case MVT::i128: \
return Enum##_16; \
switch (Opc) {
switch (ElementSize) {
case 1:
case 2:
case 4:
case 8:
case 16:
switch (ElementSize) {
case 1:
case 2:
case 4:
case 8:
case 16:
switch (ElementSize) {
case 1:
case 2:
case 4:
case 8:
case 16:
/// InitCmpLibcallCCs - Set default comparison libcall CC.
static void InitCmpLibcallCCs(ISD::CondCode *CCs) {
/// NOTE: The TargetMachine owns TLOF.
TargetLoweringBase::TargetLoweringBase(const TargetMachine &tm) : TM(tm) {
// Perform these initializations only once.
MaxStoresPerMemset = MaxStoresPerMemcpy = MaxStoresPerMemmove =
MaxLoadsPerMemcmp = 8;
MaxGluedStoresPerMemcpy = 0;
MaxStoresPerMemsetOptSize = MaxStoresPerMemcpyOptSize =
MaxStoresPerMemmoveOptSize = MaxLoadsPerMemcmpOptSize = 4;
HasMultipleConditionRegisters = false;
HasExtractBitsInsn = false;
JumpIsExpensive = JumpIsExpensiveOverride;
PredictableSelectIsExpensive = false;
EnableExtLdPromotion = false;
StackPointerRegisterToSaveRestore = 0;
BooleanContents = UndefinedBooleanContent;
BooleanFloatContents = UndefinedBooleanContent;
BooleanVectorContents = UndefinedBooleanContent;
SchedPreferenceInfo = Sched::ILP;
GatherAllAliasesMaxDepth = 18;
IsStrictFPEnabled = DisableStrictNodeMutation;
// TODO: the default will be switched to 0 in the next commit, along
// with the Target-specific changes necessary.
MaxAtomicSizeInBitsSupported = 1024;
MinCmpXchgSizeInBits = 0;
SupportsUnalignedAtomics = false;
std::fill(std::begin(LibcallRoutineNames), std::end(LibcallRoutineNames), nullptr);
void TargetLoweringBase::initActions() {
// All operations default to being supported.
memset(OpActions, 0, sizeof(OpActions));
memset(LoadExtActions, 0, sizeof(LoadExtActions));
memset(TruncStoreActions, 0, sizeof(TruncStoreActions));
memset(IndexedModeActions, 0, sizeof(IndexedModeActions));
memset(CondCodeActions, 0, sizeof(CondCodeActions));
std::fill(std::begin(RegClassForVT), std::end(RegClassForVT), nullptr);
std::end(TargetDAGCombineArray), 0);
for (MVT VT : MVT::fp_valuetypes()) {
MVT IntVT = MVT::getIntegerVT(VT.getFixedSizeInBits());
if (IntVT.isValid()) {
setOperationAction(ISD::ATOMIC_SWAP, VT, Promote);
AddPromotedToType(ISD::ATOMIC_SWAP, VT, IntVT);
// Set default actions for various operations.
for (MVT VT : MVT::all_valuetypes()) {
// Default all indexed load / store to expand.
for (unsigned IM = (unsigned)ISD::PRE_INC;
IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
setIndexedLoadAction(IM, VT, Expand);
setIndexedStoreAction(IM, VT, Expand);
setIndexedMaskedLoadAction(IM, VT, Expand);
setIndexedMaskedStoreAction(IM, VT, Expand);
// Most backends expect to see the node which just returns the value loaded.
setOperationAction(ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS, VT, Expand);
// These operations default to expand.
setOperationAction(ISD::FGETSIGN, VT, Expand);
setOperationAction(ISD::CONCAT_VECTORS, VT, Expand);
setOperationAction(ISD::FMINNUM, VT, Expand);
setOperationAction(ISD::FMAXNUM, VT, Expand);
setOperationAction(ISD::FMINNUM_IEEE, VT, Expand);
setOperationAction(ISD::FMAXNUM_IEEE, VT, Expand);
setOperationAction(ISD::FMINIMUM, VT, Expand);
setOperationAction(ISD::FMAXIMUM, VT, Expand);
setOperationAction(ISD::FMAD, VT, Expand);
setOperationAction(ISD::SMIN, VT, Expand);
setOperationAction(ISD::SMAX, VT, Expand);
setOperationAction(ISD::UMIN, VT, Expand);
setOperationAction(ISD::UMAX, VT, Expand);
setOperationAction(ISD::ABS, VT, Expand);
setOperationAction(ISD::FSHL, VT, Expand);
setOperationAction(ISD::FSHR, VT, Expand);
setOperationAction(ISD::SADDSAT, VT, Expand);
setOperationAction(ISD::UADDSAT, VT, Expand);
setOperationAction(ISD::SSUBSAT, VT, Expand);
setOperationAction(ISD::USUBSAT, VT, Expand);
setOperationAction(ISD::SSHLSAT, VT, Expand);
setOperationAction(ISD::USHLSAT, VT, Expand);
setOperationAction(ISD::SMULFIX, VT, Expand);
setOperationAction(ISD::SMULFIXSAT, VT, Expand);
setOperationAction(ISD::UMULFIX, VT, Expand);
setOperationAction(ISD::UMULFIXSAT, VT, Expand);
setOperationAction(ISD::SDIVFIX, VT, Expand);
setOperationAction(ISD::SDIVFIXSAT, VT, Expand);
setOperationAction(ISD::UDIVFIX, VT, Expand);
setOperationAction(ISD::UDIVFIXSAT, VT, Expand);
setOperationAction(ISD::FP_TO_SINT_SAT, VT, Expand);
setOperationAction(ISD::FP_TO_UINT_SAT, VT, Expand);
// Overflow operations default to expand
setOperationAction(ISD::SADDO, VT, Expand);
setOperationAction(ISD::SSUBO, VT, Expand);
setOperationAction(ISD::UADDO, VT, Expand);
setOperationAction(ISD::USUBO, VT, Expand);
setOperationAction(ISD::SMULO, VT, Expand);
setOperationAction(ISD::UMULO, VT, Expand);
// ADDCARRY operations default to expand
setOperationAction(ISD::ADDCARRY, VT, Expand);
setOperationAction(ISD::SUBCARRY, VT, Expand);
setOperationAction(ISD::SETCCCARRY, VT, Expand);
setOperationAction(ISD::SADDO_CARRY, VT, Expand);
setOperationAction(ISD::SSUBO_CARRY, VT, Expand);
// ADDC/ADDE/SUBC/SUBE default to expand.
setOperationAction(ISD::ADDC, VT, Expand);
setOperationAction(ISD::ADDE, VT, Expand);
setOperationAction(ISD::SUBC, VT, Expand);
setOperationAction(ISD::SUBE, VT, Expand);
// These default to Expand so they will be expanded to CTLZ/CTTZ by default.
setOperationAction(ISD::CTLZ_ZERO_UNDEF, VT, Expand);
setOperationAction(ISD::CTTZ_ZERO_UNDEF, VT, Expand);
setOperationAction(ISD::BITREVERSE, VT, Expand);
setOperationAction(ISD::PARITY, VT, Expand);
// These library functions default to expand.
setOperationAction(ISD::FROUND, VT, Expand);
setOperationAction(ISD::FROUNDEVEN, VT, Expand);
setOperationAction(ISD::FPOWI, VT, Expand);
// These operations default to expand for vector types.
if (VT.isVector()) {
setOperationAction(ISD::FCOPYSIGN, VT, Expand);
setOperationAction(ISD::SIGN_EXTEND_INREG, VT, Expand);
setOperationAction(ISD::ANY_EXTEND_VECTOR_INREG, VT, Expand);
setOperationAction(ISD::SIGN_EXTEND_VECTOR_INREG, VT, Expand);
setOperationAction(ISD::ZERO_EXTEND_VECTOR_INREG, VT, Expand);
setOperationAction(ISD::SPLAT_VECTOR, VT, Expand);
// Constrained floating-point operations default to expand.
setOperationAction(ISD::STRICT_##DAGN, VT, Expand);
#include "llvm/IR/ConstrainedOps.def"
// For most targets @llvm.get.dynamic.area.offset just returns 0.
setOperationAction(ISD::GET_DYNAMIC_AREA_OFFSET, VT, Expand);
// Vector reduction default to expand.
setOperationAction(ISD::VECREDUCE_FADD, VT, Expand);
setOperationAction(ISD::VECREDUCE_FMUL, VT, Expand);
setOperationAction(ISD::VECREDUCE_ADD, VT, Expand);
setOperationAction(ISD::VECREDUCE_MUL, VT, Expand);
setOperationAction(ISD::VECREDUCE_AND, VT, Expand);
setOperationAction(ISD::VECREDUCE_OR, VT, Expand);
setOperationAction(ISD::VECREDUCE_XOR, VT, Expand);
setOperationAction(ISD::VECREDUCE_SMAX, VT, Expand);
setOperationAction(ISD::VECREDUCE_SMIN, VT, Expand);
setOperationAction(ISD::VECREDUCE_UMAX, VT, Expand);
setOperationAction(ISD::VECREDUCE_UMIN, VT, Expand);
setOperationAction(ISD::VECREDUCE_FMAX, VT, Expand);
setOperationAction(ISD::VECREDUCE_FMIN, VT, Expand);
setOperationAction(ISD::VECREDUCE_SEQ_FADD, VT, Expand);
setOperationAction(ISD::VECREDUCE_SEQ_FMUL, VT, Expand);
// Most targets ignore the @llvm.prefetch intrinsic.
setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
// Most targets also ignore the @llvm.readcyclecounter intrinsic.
setOperationAction(ISD::READCYCLECOUNTER, MVT::i64, Expand);
// ConstantFP nodes default to expand. Targets can either change this to
// Legal, in which case all fp constants are legal, or use isFPImmLegal()
// to optimize expansions for certain constants.
setOperationAction(ISD::ConstantFP, MVT::f16, Expand);
setOperationAction(ISD::ConstantFP, MVT::f32, Expand);
setOperationAction(ISD::ConstantFP, MVT::f64, Expand);
setOperationAction(ISD::ConstantFP, MVT::f80, Expand);
setOperationAction(ISD::ConstantFP, MVT::f128, Expand);
// These library functions default to expand.
for (MVT VT : {MVT::f32, MVT::f64, MVT::f128}) {
setOperationAction(ISD::FCBRT, VT, Expand);
setOperationAction(ISD::FLOG , VT, Expand);
setOperationAction(ISD::FLOG2, VT, Expand);
setOperationAction(ISD::FLOG10, VT, Expand);
setOperationAction(ISD::FEXP , VT, Expand);
setOperationAction(ISD::FEXP2, VT, Expand);
setOperationAction(ISD::FFLOOR, VT, Expand);
setOperationAction(ISD::FNEARBYINT, VT, Expand);
setOperationAction(ISD::FCEIL, VT, Expand);
setOperationAction(ISD::FRINT, VT, Expand);
setOperationAction(ISD::FTRUNC, VT, Expand);
setOperationAction(ISD::FROUND, VT, Expand);
setOperationAction(ISD::FROUNDEVEN, VT, Expand);
setOperationAction(ISD::LROUND, VT, Expand);
setOperationAction(ISD::LLROUND, VT, Expand);
setOperationAction(ISD::LRINT, VT, Expand);
setOperationAction(ISD::LLRINT, VT, Expand);
// Default ISD::TRAP to expand (which turns it into abort).
setOperationAction(ISD::TRAP, MVT::Other, Expand);
// On most systems, DEBUGTRAP and TRAP have no difference. The "Expand"
// here is to inform DAG Legalizer to replace DEBUGTRAP with TRAP.
setOperationAction(ISD::DEBUGTRAP, MVT::Other, Expand);
setOperationAction(ISD::UBSANTRAP, MVT::Other, Expand);
MVT TargetLoweringBase::getScalarShiftAmountTy(const DataLayout &DL,
EVT) const {
return MVT::getIntegerVT(DL.getPointerSizeInBits(0));
EVT TargetLoweringBase::getShiftAmountTy(EVT LHSTy, const DataLayout &DL,
bool LegalTypes) const {
assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
if (LHSTy.isVector())
return LHSTy;
return LegalTypes ? getScalarShiftAmountTy(DL, LHSTy)
: getPointerTy(DL);
bool TargetLoweringBase::canOpTrap(unsigned Op, EVT VT) const {
switch (Op) {
return false;
case ISD::SDIV:
case ISD::UDIV:
case ISD::SREM:
case ISD::UREM:
return true;
bool TargetLoweringBase::isFreeAddrSpaceCast(unsigned SrcAS,
unsigned DestAS) const {
return TM.isNoopAddrSpaceCast(SrcAS, DestAS);
void TargetLoweringBase::setJumpIsExpensive(bool isExpensive) {
// If the command-line option was specified, ignore this request.
if (!JumpIsExpensiveOverride.getNumOccurrences())
JumpIsExpensive = isExpensive;
TargetLoweringBase::getTypeConversion(LLVMContext &Context, EVT VT) const {
// If this is a simple type, use the ComputeRegisterProp mechanism.
if (VT.isSimple()) {
MVT SVT = VT.getSimpleVT();
assert((unsigned)SVT.SimpleTy < array_lengthof(TransformToType));
MVT NVT = TransformToType[SVT.SimpleTy];
LegalizeTypeAction LA = ValueTypeActions.getTypeAction(SVT);
assert((LA == TypeLegal || LA == TypeSoftenFloat ||
LA == TypeSoftPromoteHalf ||
(NVT.isVector() ||
ValueTypeActions.getTypeAction(NVT) != TypePromoteInteger)) &&
"Promote may not follow Expand or Promote");
if (LA == TypeSplitVector)
return LegalizeKind(LA, EVT(SVT).getHalfNumVectorElementsVT(Context));
if (LA == TypeScalarizeVector)
return LegalizeKind(LA, SVT.getVectorElementType());
return LegalizeKind(LA, NVT);
// Handle Extended Scalar Types.
if (!VT.isVector()) {
assert(VT.isInteger() && "Float types must be simple");
unsigned BitSize = VT.getSizeInBits();
// First promote to a power-of-two size, then expand if necessary.
if (BitSize < 8 || !isPowerOf2_32(BitSize)) {
EVT NVT = VT.getRoundIntegerType(Context);
assert(NVT != VT && "Unable to round integer VT");
LegalizeKind NextStep = getTypeConversion(Context, NVT);
// Avoid multi-step promotion.
if (NextStep.first == TypePromoteInteger)
return NextStep;
// Return rounded integer type.
return LegalizeKind(TypePromoteInteger, NVT);
return LegalizeKind(TypeExpandInteger,
EVT::getIntegerVT(Context, VT.getSizeInBits() / 2));
// Handle vector types.
ElementCount NumElts = VT.getVectorElementCount();
EVT EltVT = VT.getVectorElementType();
// Vectors with only one element are always scalarized.
if (NumElts.isScalar())
return LegalizeKind(TypeScalarizeVector, EltVT);
if (VT.getVectorElementCount() == ElementCount::getScalable(1))
report_fatal_error("Cannot legalize this vector");
// Try to widen vector elements until the element type is a power of two and
// promote it to a legal type later on, for example:
// <3 x i8> -> <4 x i8> -> <4 x i32>
if (EltVT.isInteger()) {
// Vectors with a number of elements that is not a power of two are always
// widened, for example <3 x i8> -> <4 x i8>.
if (!VT.isPow2VectorType()) {
NumElts = NumElts.coefficientNextPowerOf2();
EVT NVT = EVT::getVectorVT(Context, EltVT, NumElts);
return LegalizeKind(TypeWidenVector, NVT);
// Examine the element type.
LegalizeKind LK = getTypeConversion(Context, EltVT);
// If type is to be expanded, split the vector.
// <4 x i140> -> <2 x i140>
if (LK.first == TypeExpandInteger)
return LegalizeKind(TypeSplitVector,
// Promote the integer element types until a legal vector type is found
// or until the element integer type is too big. If a legal type was not
// found, fallback to the usual mechanism of widening/splitting the
// vector.
EVT OldEltVT = EltVT;
while (true) {
// Increase the bitwidth of the element to the next pow-of-two
// (which is greater than 8 bits).
EltVT = EVT::getIntegerVT(Context, 1 + EltVT.getSizeInBits())
// Stop trying when getting a non-simple element type.
// Note that vector elements may be greater than legal vector element
// types. Example: X86 XMM registers hold 64bit element on 32bit
// systems.
if (!EltVT.isSimple())
// Build a new vector type and check if it is legal.
MVT NVT = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
// Found a legal promoted vector type.
if (NVT != MVT() && ValueTypeActions.getTypeAction(NVT) == TypeLegal)
return LegalizeKind(TypePromoteInteger,
EVT::getVectorVT(Context, EltVT, NumElts));
// Reset the type to the unexpanded type if we did not find a legal vector
// type with a promoted vector element type.
EltVT = OldEltVT;
// Try to widen the vector until a legal type is found.
// If there is no wider legal type, split the vector.
while (true) {
// Round up to the next power of 2.
NumElts = NumElts.coefficientNextPowerOf2();
// If there is no simple vector type with this many elements then there
// cannot be a larger legal vector type. Note that this assumes that
// there are no skipped intermediate vector types in the simple types.
if (!EltVT.isSimple())
MVT LargerVector = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
if (LargerVector == MVT())
// If this type is legal then widen the vector.
if (ValueTypeActions.getTypeAction(LargerVector) == TypeLegal)
return LegalizeKind(TypeWidenVector, LargerVector);
// Widen odd vectors to next power of two.
if (!VT.isPow2VectorType()) {
EVT NVT = VT.getPow2VectorType(Context);
return LegalizeKind(TypeWidenVector, NVT);
// Vectors with illegal element types are expanded.
EVT NVT = EVT::getVectorVT(Context, EltVT,
return LegalizeKind(TypeSplitVector, NVT);
static unsigned getVectorTypeBreakdownMVT(MVT VT, MVT &IntermediateVT,
unsigned &NumIntermediates,
MVT &RegisterVT,
TargetLoweringBase *TLI) {
// Figure out the right, legal destination reg to copy into.
ElementCount EC = VT.getVectorElementCount();
MVT EltTy = VT.getVectorElementType();
unsigned NumVectorRegs = 1;
// Scalable vectors cannot be scalarized, so splitting or widening is
// required.
if (VT.isScalableVector() && !isPowerOf2_32(EC.getKnownMinValue()))
"Splitting or widening of non-power-of-2 MVTs is not implemented.");
// FIXME: We don't support non-power-of-2-sized vectors for now.
// Ideally we could break down into LHS/RHS like LegalizeDAG does.
if (!isPowerOf2_32(EC.getKnownMinValue())) {
// Split EC to unit size (scalable property is preserved).
NumVectorRegs = EC.getKnownMinValue();
EC = ElementCount::getFixed(1);
// Divide the input until we get to a supported size. This will
// always end up with an EC that represent a scalar or a scalable
// scalar.
while (EC.getKnownMinValue() > 1 &&
!TLI->isTypeLegal(MVT::getVectorVT(EltTy, EC))) {
EC = EC.divideCoefficientBy(2);
NumVectorRegs <<= 1;
NumIntermediates = NumVectorRegs;
MVT NewVT = MVT::getVectorVT(EltTy, EC);
if (!TLI->isTypeLegal(NewVT))
NewVT = EltTy;
IntermediateVT = NewVT;
unsigned LaneSizeInBits = NewVT.getScalarSizeInBits();
// Convert sizes such as i33 to i64.
if (!isPowerOf2_32(LaneSizeInBits))
LaneSizeInBits = NextPowerOf2(LaneSizeInBits);
MVT DestVT = TLI->getRegisterType(NewVT);
RegisterVT = DestVT;
if (EVT(DestVT).bitsLT(NewVT)) // Value is expanded, e.g. i64 -> i16.
return NumVectorRegs * (LaneSizeInBits / DestVT.getScalarSizeInBits());
// Otherwise, promotion or legal types use the same number of registers as
// the vector decimated to the appropriate level.
return NumVectorRegs;
/// isLegalRC - Return true if the value types that can be represented by the
/// specified register class are all legal.
bool TargetLoweringBase::isLegalRC(const TargetRegisterInfo &TRI,
const TargetRegisterClass &RC) const {
for (auto I = TRI.legalclasstypes_begin(RC); *I != MVT::Other; ++I)
if (isTypeLegal(*I))
return true;
return false;
/// Replace/modify any TargetFrameIndex operands with a targte-dependent
/// sequence of memory operands that is recognized by PrologEpilogInserter.
MachineBasicBlock *
TargetLoweringBase::emitPatchPoint(MachineInstr &InitialMI,
MachineBasicBlock *MBB) const {
MachineInstr *MI = &InitialMI;
MachineFunction &MF = *MI->getMF();
MachineFrameInfo &MFI = MF.getFrameInfo();
// We're handling multiple types of operands here:
// PATCHPOINT MetaArgs - live-in, read only, direct
// STATEPOINT Deopt Spill - live-through, read only, indirect
// STATEPOINT Deopt Alloca - live-through, read only, direct
// (We're currently conservative and mark the deopt slots read/write in
// practice.)
// STATEPOINT GC Spill - live-through, read/write, indirect
// STATEPOINT GC Alloca - live-through, read/write, direct
// The live-in vs live-through is handled already (the live through ones are
// all stack slots), but we need to handle the different type of stackmap
// operands and memory effects here.
if (!llvm::any_of(MI->operands(),
[](MachineOperand &Operand) { return Operand.isFI(); }))
return MBB;
MachineInstrBuilder MIB = BuildMI(MF, MI->getDebugLoc(), MI->getDesc());
// Inherit previous memory operands.
for (unsigned i = 0; i < MI->getNumOperands(); ++i) {
MachineOperand &MO = MI->getOperand(i);
if (!MO.isFI()) {
// Index of Def operand this Use it tied to.
// Since Defs are coming before Uses, if Use is tied, then
// index of Def must be smaller that index of that Use.
// Also, Defs preserve their position in new MI.
unsigned TiedTo = i;
if (MO.isReg() && MO.isTied())
TiedTo = MI->findTiedOperandIdx(i);
if (TiedTo < i)
MIB->tieOperands(TiedTo, MIB->getNumOperands() - 1);
// foldMemoryOperand builds a new MI after replacing a single FI operand
// with the canonical set of five x86 addressing-mode operands.
int FI = MO.getIndex();
// Add frame index operands recognized by stackmaps.cpp
if (MFI.isStatepointSpillSlotObjectIndex(FI)) {
// indirect-mem-ref tag, size, #FI, offset.
// Used for spills inserted by StatepointLowering. This codepath is not
// used for patchpoints/stackmaps at all, for these spilling is done via
// foldMemoryOperand callback only.
assert(MI->getOpcode() == TargetOpcode::STATEPOINT && "sanity");
} else {
// direct-mem-ref tag, #FI, offset.
// Used by patchpoint, and direct alloca arguments to statepoints
assert(MIB->mayLoad() && "Folded a stackmap use to a non-load!");
// Add a new memory operand for this FI.
assert(MFI.getObjectOffset(FI) != -1);
// Note: STATEPOINT MMOs are added during SelectionDAG. STACKMAP, and
// PATCHPOINT should be updated to do the same. (TODO)
if (MI->getOpcode() != TargetOpcode::STATEPOINT) {
auto Flags = MachineMemOperand::MOLoad;
MachineMemOperand *MMO = MF.getMachineMemOperand(
MachinePointerInfo::getFixedStack(MF, FI), Flags,
MF.getDataLayout().getPointerSize(), MFI.getObjectAlign(FI));
MIB->addMemOperand(MF, MMO);
MBB->insert(MachineBasicBlock::iterator(MI), MIB);
return MBB;
/// findRepresentativeClass - Return the largest legal super-reg register class
/// of the register class for the specified type and its associated "cost".
// This function is in TargetLowering because it uses RegClassForVT which would
// need to be moved to TargetRegisterInfo and would necessitate moving
// isTypeLegal over as well - a massive change that would just require
// TargetLowering having a TargetRegisterInfo class member that it would use.
std::pair<const TargetRegisterClass *, uint8_t>
TargetLoweringBase::findRepresentativeClass(const TargetRegisterInfo *TRI,
MVT VT) const {
const TargetRegisterClass *RC = RegClassForVT[VT.SimpleTy];
if (!RC)
return std::make_pair(RC, 0);
// Compute the set of all super-register classes.
BitVector SuperRegRC(TRI->getNumRegClasses());
for (SuperRegClassIterator RCI(RC, TRI); RCI.isValid(); ++RCI)
// Find the first legal register class with the largest spill size.
const TargetRegisterClass *BestRC = RC;
for (unsigned i : SuperRegRC.set_bits()) {
const TargetRegisterClass *SuperRC = TRI->getRegClass(i);
// We want the largest possible spill size.
if (TRI->getSpillSize(*SuperRC) <= TRI->getSpillSize(*BestRC))
if (!isLegalRC(*TRI, *SuperRC))
BestRC = SuperRC;
return std::make_pair(BestRC, 1);
/// computeRegisterProperties - Once all of the register classes are added,
/// this allows us to compute derived properties we expose.
void TargetLoweringBase::computeRegisterProperties(
const TargetRegisterInfo *TRI) {
"Too many value types for ValueTypeActions to hold!");
// Everything defaults to needing one register.
for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) {
NumRegistersForVT[i] = 1;
RegisterTypeForVT[i] = TransformToType[i] = (MVT::SimpleValueType)i;
// ...except isVoid, which doesn't need any registers.
NumRegistersForVT[MVT::isVoid] = 0;
// Find the largest integer register class.
unsigned LargestIntReg = MVT::LAST_INTEGER_VALUETYPE;
for (; RegClassForVT[LargestIntReg] == nullptr; --LargestIntReg)
assert(LargestIntReg != MVT::i1 && "No integer registers defined!");
// Every integer value type larger than this largest register takes twice as
// many registers to represent as the previous ValueType.
for (unsigned ExpandedReg = LargestIntReg + 1;
ExpandedReg <= MVT::LAST_INTEGER_VALUETYPE; ++ExpandedReg) {
NumRegistersForVT[ExpandedReg] = 2*NumRegistersForVT[ExpandedReg-1];
RegisterTypeForVT[ExpandedReg] = (MVT::SimpleValueType)LargestIntReg;
TransformToType[ExpandedReg] = (MVT::SimpleValueType)(ExpandedReg - 1);
// Inspect all of the ValueType's smaller than the largest integer
// register to see which ones need promotion.
unsigned LegalIntReg = LargestIntReg;
for (unsigned IntReg = LargestIntReg - 1;
IntReg >= (unsigned)MVT::i1; --IntReg) {
MVT IVT = (MVT::SimpleValueType)IntReg;
if (isTypeLegal(IVT)) {
LegalIntReg = IntReg;
} else {
RegisterTypeForVT[IntReg] = TransformToType[IntReg] =
ValueTypeActions.setTypeAction(IVT, TypePromoteInteger);
// ppcf128 type is really two f64's.
if (!isTypeLegal(MVT::ppcf128)) {
if (isTypeLegal(MVT::f64)) {
NumRegistersForVT[MVT::ppcf128] = 2*NumRegistersForVT[MVT::f64];
RegisterTypeForVT[MVT::ppcf128] = MVT::f64;
TransformToType[MVT::ppcf128] = MVT::f64;
ValueTypeActions.setTypeAction(MVT::ppcf128, TypeExpandFloat);
} else {
NumRegistersForVT[MVT::ppcf128] = NumRegistersForVT[MVT::i128];
RegisterTypeForVT[MVT::ppcf128] = RegisterTypeForVT[MVT::i128];
TransformToType[MVT::ppcf128] = MVT::i128;
ValueTypeActions.setTypeAction(MVT::ppcf128, TypeSoftenFloat);
// Decide how to handle f128. If the target does not have native f128 support,
// expand it to i128 and we will be generating soft float library calls.
if (!isTypeLegal(MVT::f128)) {
NumRegistersForVT[MVT::f128] = NumRegistersForVT[MVT::i128];
RegisterTypeForVT[MVT::f128] = RegisterTypeForVT[MVT::i128];
TransformToType[MVT::f128] = MVT::i128;
ValueTypeActions.setTypeAction(MVT::f128, TypeSoftenFloat);
// Decide how to handle f64. If the target does not have native f64 support,
// expand it to i64 and we will be generating soft float library calls.
if (!isTypeLegal(MVT::f64)) {
NumRegistersForVT[MVT::f64] = NumRegistersForVT[MVT::i64];
RegisterTypeForVT[MVT::f64] = RegisterTypeForVT[MVT::i64];
TransformToType[MVT::f64] = MVT::i64;
ValueTypeActions.setTypeAction(MVT::f64, TypeSoftenFloat);
// Decide how to handle f32. If the target does not have native f32 support,
// expand it to i32 and we will be generating soft float library calls.
if (!isTypeLegal(MVT::f32)) {
NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::i32];
RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::i32];
TransformToType[MVT::f32] = MVT::i32;
ValueTypeActions.setTypeAction(MVT::f32, TypeSoftenFloat);
// Decide how to handle f16. If the target does not have native f16 support,
// promote it to f32, because there are no f16 library calls (except for
// conversions).
if (!isTypeLegal(MVT::f16)) {
// Allow targets to control how we legalize half.
if (softPromoteHalfType()) {
NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::i16];
RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::i16];
TransformToType[MVT::f16] = MVT::f32;
ValueTypeActions.setTypeAction(MVT::f16, TypeSoftPromoteHalf);
} else {
NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::f32];
RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::f32];
TransformToType[MVT::f16] = MVT::f32;
ValueTypeActions.setTypeAction(MVT::f16, TypePromoteFloat);
// Loop over all of the vector value types to see which need transformations.
for (unsigned i = MVT::FIRST_VECTOR_VALUETYPE;
i <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++i) {
MVT VT = (MVT::SimpleValueType) i;
if (isTypeLegal(VT))
MVT EltVT = VT.getVectorElementType();
ElementCount EC = VT.getVectorElementCount();
bool IsLegalWiderType = false;
bool IsScalable = VT.isScalableVector();
LegalizeTypeAction PreferredAction = getPreferredVectorAction(VT);
switch (PreferredAction) {
case TypePromoteInteger: {
MVT::SimpleValueType EndVT = IsScalable ?
// Try to promote the elements of integer vectors. If no legal
// promotion was found, fall through to the widen-vector method.
for (unsigned nVT = i + 1;
(MVT::SimpleValueType)nVT <= EndVT; ++nVT) {
MVT SVT = (MVT::SimpleValueType) nVT;
// Promote vectors of integers to vectors with the same number
// of elements, with a wider element type.
if (SVT.getScalarSizeInBits() > EltVT.getFixedSizeInBits() &&
SVT.getVectorElementCount() == EC && isTypeLegal(SVT)) {
TransformToType[i] = SVT;
RegisterTypeForVT[i] = SVT;
NumRegistersForVT[i] = 1;
ValueTypeActions.setTypeAction(VT, TypePromoteInteger);
IsLegalWiderType = true;
if (IsLegalWiderType)
case TypeWidenVector:
if (isPowerOf2_32(EC.getKnownMinValue())) {
// Try to widen the vector.
for (unsigned nVT = i + 1; nVT <= MVT::LAST_VECTOR_VALUETYPE; ++nVT) {
MVT SVT = (MVT::SimpleValueType) nVT;
if (SVT.getVectorElementType() == EltVT &&
SVT.isScalableVector() == IsScalable &&
SVT.getVectorElementCount().getKnownMinValue() >
EC.getKnownMinValue() &&
isTypeLegal(SVT)) {
TransformToType[i] = SVT;
RegisterTypeForVT[i] = SVT;
NumRegistersForVT[i] = 1;
ValueTypeActions.setTypeAction(VT, TypeWidenVector);
IsLegalWiderType = true;
if (IsLegalWiderType)
} else {
// Only widen to the next power of 2 to keep consistency with EVT.
MVT NVT = VT.getPow2VectorType();
if (isTypeLegal(NVT)) {
TransformToType[i] = NVT;
ValueTypeActions.setTypeAction(VT, TypeWidenVector);
RegisterTypeForVT[i] = NVT;
NumRegistersForVT[i] = 1;
case TypeSplitVector:
case TypeScalarizeVector: {
MVT IntermediateVT;
MVT RegisterVT;
unsigned NumIntermediates;
unsigned NumRegisters = getVectorTypeBreakdownMVT(VT, IntermediateVT,
NumIntermediates, RegisterVT, this);
NumRegistersForVT[i] = NumRegisters;
assert(NumRegistersForVT[i] == NumRegisters &&
"NumRegistersForVT size cannot represent NumRegisters!");
RegisterTypeForVT[i] = RegisterVT;
MVT NVT = VT.getPow2VectorType();
if (NVT == VT) {
// Type is already a power of 2. The default action is to split.
TransformToType[i] = MVT::Other;
if (PreferredAction == TypeScalarizeVector)
ValueTypeActions.setTypeAction(VT, TypeScalarizeVector);
else if (PreferredAction == TypeSplitVector)
ValueTypeActions.setTypeAction(VT, TypeSplitVector);
else if (EC.getKnownMinValue() > 1)
ValueTypeActions.setTypeAction(VT, TypeSplitVector);
ValueTypeActions.setTypeAction(VT, EC.isScalable()
? TypeScalarizeScalableVector
: TypeScalarizeVector);
} else {
TransformToType[i] = NVT;
ValueTypeActions.setTypeAction(VT, TypeWidenVector);
llvm_unreachable("Unknown vector legalization action!");
// Determine the 'representative' register class for each value type.
// An representative register class is the largest (meaning one which is
// not a sub-register class / subreg register class) legal register class for
// a group of value types. For example, on i386, i8, i16, and i32
// representative would be GR32; while on x86_64 it's GR64.
for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) {
const TargetRegisterClass* RRC;
uint8_t Cost;
std::tie(RRC, Cost) = findRepresentativeClass(TRI, (MVT::SimpleValueType)i);
RepRegClassForVT[i] = RRC;
RepRegClassCostForVT[i] = Cost;
EVT TargetLoweringBase::getSetCCResultType(const DataLayout &DL, LLVMContext &,
EVT VT) const {
assert(!VT.isVector() && "No default SetCC type for vectors!");
return getPointerTy(DL).SimpleTy;
MVT::SimpleValueType TargetLoweringBase::getCmpLibcallReturnType() const {
return MVT::i32; // return the default value
/// getVectorTypeBreakdown - Vector types are broken down into some number of
/// legal first class types. For example, MVT::v8f32 maps to 2 MVT::v4f32
/// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack.
/// Similarly, MVT::v2i64 turns into 4 MVT::i32 values with both PPC and X86.
/// This method returns the number of registers needed, and the VT for each
/// register. It also returns the VT and quantity of the intermediate values
/// before they are promoted/expanded.
unsigned TargetLoweringBase::getVectorTypeBreakdown(LLVMContext &Context, EVT VT,
EVT &IntermediateVT,
unsigned &NumIntermediates,
MVT &RegisterVT) const {
ElementCount EltCnt = VT.getVectorElementCount();
// If there is a wider vector type with the same element type as this one,
// or a promoted vector type that has the same number of elements which
// are wider, then we should convert to that legal vector type.
// This handles things like <2 x float> -> <4 x float> and
// <4 x i1> -> <4 x i32>.
LegalizeTypeAction TA = getTypeAction(Context, VT);
if (EltCnt.getKnownMinValue() != 1 &&
(TA == TypeWidenVector || TA == TypePromoteInteger)) {
EVT RegisterEVT = getTypeToTransformTo(Context, VT);
if (isTypeLegal(RegisterEVT)) {
IntermediateVT = RegisterEVT;
RegisterVT = RegisterEVT.getSimpleVT();
NumIntermediates = 1;
return 1;
// Figure out the right, legal destination reg to copy into.
EVT EltTy = VT.getVectorElementType();
unsigned NumVectorRegs = 1;
// Scalable vectors cannot be scalarized, so handle the legalisation of the
// types like done elsewhere in SelectionDAG.
if (VT.isScalableVector() && !isPowerOf2_32(EltCnt.getKnownMinValue())) {
LegalizeKind LK;
EVT PartVT = VT;
do {
// Iterate until we've found a legal (part) type to hold VT.
LK = getTypeConversion(Context, PartVT);
PartVT = LK.second;
} while (LK.first != TypeLegal);
NumIntermediates = VT.getVectorElementCount().getKnownMinValue() /
// FIXME: This code needs to be extended to handle more complex vector
// breakdowns, like nxv7i64 -> nxv8i64 -> 4 x nxv2i64. Currently the only
// supported cases are vectors that are broken down into equal parts
// such as nxv6i64 -> 3 x nxv2i64.
assert((PartVT.getVectorElementCount() * NumIntermediates) ==
VT.getVectorElementCount() &&
"Expected an integer multiple of PartVT");
IntermediateVT = PartVT;
RegisterVT = getRegisterType(Context, IntermediateVT);
return NumIntermediates;
// FIXME: We don't support non-power-of-2-sized vectors for now. Ideally
// we could break down into LHS/RHS like LegalizeDAG does.
if (!isPowerOf2_32(EltCnt.getKnownMinValue())) {
NumVectorRegs = EltCnt.getKnownMinValue();
EltCnt = ElementCount::getFixed(1);
// Divide the input until we get to a supported size. This will always
// end with a scalar if the target doesn't support vectors.
while (EltCnt.getKnownMinValue() > 1 &&
!isTypeLegal(EVT::getVectorVT(Context, EltTy, EltCnt))) {
EltCnt = EltCnt.divideCoefficientBy(2);
NumVectorRegs <<= 1;
NumIntermediates = NumVectorRegs;
EVT NewVT = EVT::getVectorVT(Context, EltTy, EltCnt);
if (!isTypeLegal(NewVT))
NewVT = EltTy;
IntermediateVT = NewVT;
MVT DestVT = getRegisterType(Context, NewVT);
RegisterVT = DestVT;
if (EVT(DestVT).bitsLT(NewVT)) { // Value is expanded, e.g. i64 -> i16.
TypeSize NewVTSize = NewVT.getSizeInBits();
// Convert sizes such as i33 to i64.
if (!isPowerOf2_32(NewVTSize.getKnownMinSize()))
NewVTSize = NewVTSize.coefficientNextPowerOf2();
return NumVectorRegs*(NewVTSize/DestVT.getSizeInBits());
// Otherwise, promotion or legal types use the same number of registers as
// the vector decimated to the appropriate level.
return NumVectorRegs;
bool TargetLoweringBase::isSuitableForJumpTable(const SwitchInst *SI,
uint64_t NumCases,
uint64_t Range,
ProfileSummaryInfo *PSI,
BlockFrequencyInfo *BFI) const {
// FIXME: This function check the maximum table size and density, but the
// minimum size is not checked. It would be nice if the minimum size is
// also combined within this function. Currently, the minimum size check is
// performed in findJumpTable() in SelectionDAGBuiler and
// getEstimatedNumberOfCaseClusters() in BasicTTIImpl.
const bool OptForSize =
SI->getParent()->getParent()->hasOptSize() ||
llvm::shouldOptimizeForSize(SI->getParent(), PSI, BFI);
const unsigned MinDensity = getMinimumJumpTableDensity(OptForSize);
const unsigned MaxJumpTableSize = getMaximumJumpTableSize();
// Check whether the number of cases is small enough and
// the range is dense enough for a jump table.
return (OptForSize || Range <= MaxJumpTableSize) &&
(NumCases * 100 >= Range * MinDensity);
/// Get the EVTs and ArgFlags collections that represent the legalized return
/// type of the given function. This does not require a DAG or a return value,
/// and is suitable for use before any DAGs for the function are constructed.
/// TODO: Move this out of TargetLowering.cpp.
void llvm::GetReturnInfo(CallingConv::ID CC, Type *ReturnType,
AttributeList attr,
SmallVectorImpl<ISD::OutputArg> &Outs,
const TargetLowering &TLI, const DataLayout &DL) {
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, DL, ReturnType, ValueVTs);
unsigned NumValues = ValueVTs.size();
if (NumValues == 0) return;
for (unsigned j = 0, f = NumValues; j != f; ++j) {
EVT VT = ValueVTs[j];
ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::SExt))
ExtendKind = ISD::SIGN_EXTEND;
else if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::ZExt))
ExtendKind = ISD::ZERO_EXTEND;
// FIXME: C calling convention requires the return type to be promoted to
// at least 32-bit. But this is not necessary for non-C calling
// conventions. The frontend should mark functions whose return values
// require promoting with signext or zeroext attributes.
if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger()) {
MVT MinVT = TLI.getRegisterType(ReturnType->getContext(), MVT::i32);
if (VT.bitsLT(MinVT))
VT = MinVT;
unsigned NumParts =
TLI.getNumRegistersForCallingConv(ReturnType->getContext(), CC, VT);
MVT PartVT =
TLI.getRegisterTypeForCallingConv(ReturnType->getContext(), CC, VT);
// 'inreg' on function refers to return value
ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::InReg))
// Propagate extension type if any
if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::SExt))
else if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::ZExt))
for (unsigned i = 0; i < NumParts; ++i)
Outs.push_back(ISD::OutputArg(Flags, PartVT, VT, /*isfixed=*/true, 0, 0));
/// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
/// function arguments in the caller parameter area. This is the actual
/// alignment, not its logarithm.
unsigned TargetLoweringBase::getByValTypeAlignment(Type *Ty,
const DataLayout &DL) const {
return DL.getABITypeAlign(Ty).value();
bool TargetLoweringBase::allowsMemoryAccessForAlignment(
LLVMContext &Context, const DataLayout &DL, EVT VT, unsigned AddrSpace,
Align Alignment, MachineMemOperand::Flags Flags, bool *Fast) const {
// Check if the specified alignment is sufficient based on the data layout.
// TODO: While using the data layout works in practice, a better solution
// would be to implement this check directly (make this a virtual function).
// For example, the ABI alignment may change based on software platform while
// this function should only be affected by hardware implementation.
Type *Ty = VT.getTypeForEVT(Context);
if (Alignment >= DL.getABITypeAlign(Ty)) {
// Assume that an access that meets the ABI-specified alignment is fast.
if (Fast != nullptr)
*Fast = true;
return true;
// This is a misaligned access.
return allowsMisalignedMemoryAccesses(VT, AddrSpace, Alignment, Flags, Fast);
bool TargetLoweringBase::allowsMemoryAccessForAlignment(
LLVMContext &Context, const DataLayout &DL, EVT VT,
const MachineMemOperand &MMO, bool *Fast) const {
return allowsMemoryAccessForAlignment(Context, DL, VT, MMO.getAddrSpace(),
MMO.getAlign(), MMO.getFlags(), Fast);
bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
const DataLayout &DL, EVT VT,
unsigned AddrSpace, Align Alignment,
MachineMemOperand::Flags Flags,
bool *Fast) const {
return allowsMemoryAccessForAlignment(Context, DL, VT, AddrSpace, Alignment,
Flags, Fast);
bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
const DataLayout &DL, EVT VT,
const MachineMemOperand &MMO,
bool *Fast) const {
return allowsMemoryAccess(Context, DL, VT, MMO.getAddrSpace(), MMO.getAlign(),
MMO.getFlags(), Fast);
bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
const DataLayout &DL, LLT Ty,
const MachineMemOperand &MMO,
bool *Fast) const {
return allowsMemoryAccess(Context, DL, getMVTForLLT(Ty), MMO.getAddrSpace(),
MMO.getAlign(), MMO.getFlags(), Fast);
BranchProbability TargetLoweringBase::getPredictableBranchThreshold() const {
return BranchProbability(MinPercentageForPredictableBranch, 100);
// TargetTransformInfo Helpers
int TargetLoweringBase::InstructionOpcodeToISD(unsigned Opcode) const {
enum InstructionOpcodes {
#define LAST_OTHER_INST(NUM) InstructionOpcodesCount = NUM
#include "llvm/IR/Instruction.def"
switch (static_cast<InstructionOpcodes>(Opcode)) {
case Ret: return 0;
case Br: return 0;
case Switch: return 0;
case IndirectBr: return 0;
case Invoke: return 0;
case CallBr: return 0;
case Resume: return 0;
case Unreachable: return 0;
case CleanupRet: return 0;
case CatchRet: return 0;
case CatchPad: return 0;
case CatchSwitch: return 0;
case CleanupPad: return 0;
case FNeg: return ISD::FNEG;
case Add: return ISD::ADD;
case FAdd: return ISD::FADD;
case Sub: return ISD::SUB;
case FSub: return ISD::FSUB;
case Mul: return ISD::MUL;
case FMul: return ISD::FMUL;
case UDiv: return ISD::UDIV;
case SDiv: return ISD::SDIV;
case FDiv: return ISD::FDIV;
case URem: return ISD::UREM;
case SRem: return ISD::SREM;
case FRem: return ISD::FREM;
case Shl: return ISD::SHL;
case LShr: return ISD::SRL;
case AShr: return ISD::SRA;
case And: return ISD::AND;
case Or: return ISD::OR;
case Xor: return ISD::XOR;
case Alloca: return 0;
case Load: return ISD::LOAD;
case Store: return ISD::STORE;
case GetElementPtr: return 0;
case Fence: return 0;
case AtomicCmpXchg: return 0;
case AtomicRMW: return 0;
case Trunc: return ISD::TRUNCATE;
case ZExt: return ISD::ZERO_EXTEND;
case SExt: return ISD::SIGN_EXTEND;
case FPToUI: return ISD::FP_TO_UINT;
case FPToSI: return ISD::FP_TO_SINT;
case UIToFP: return ISD::UINT_TO_FP;
case SIToFP: return ISD::SINT_TO_FP;
case FPTrunc: return ISD::FP_ROUND;
case FPExt: return ISD::FP_EXTEND;
case PtrToInt: return ISD::BITCAST;
case IntToPtr: return ISD::BITCAST;
case BitCast: return ISD::BITCAST;
case AddrSpaceCast: return ISD::ADDRSPACECAST;
case ICmp: return ISD::SETCC;
case FCmp: return ISD::SETCC;
case PHI: return 0;
case Call: return 0;
case Select: return ISD::SELECT;
case UserOp1: return 0;
case UserOp2: return 0;
case VAArg: return 0;
case ExtractElement: return ISD::EXTRACT_VECTOR_ELT;
case InsertElement: return ISD::INSERT_VECTOR_ELT;
case ShuffleVector: return ISD::VECTOR_SHUFFLE;
case ExtractValue: return ISD::MERGE_VALUES;
case InsertValue: return ISD::MERGE_VALUES;
case LandingPad: return 0;
case Freeze: return ISD::FREEZE;
llvm_unreachable("Unknown instruction type encountered!");
std::pair<int, MVT>
TargetLoweringBase::getTypeLegalizationCost(const DataLayout &DL,
Type *Ty) const {
LLVMContext &C = Ty->getContext();
EVT MTy = getValueType(DL, Ty);
int Cost = 1;
// We keep legalizing the type until we find a legal kind. We assume that
// the only operation that costs anything is the split. After splitting
// we need to handle two types.
while (true) {
LegalizeKind LK = getTypeConversion(C, MTy);
if (LK.first == TypeLegal)
return std::make_pair(Cost, MTy.getSimpleVT());
if (LK.first == TypeSplitVector || LK.first == TypeExpandInteger)
Cost *= 2;
// Do not loop with f128 type.
if (MTy == LK.second)
return std::make_pair(Cost, MTy.getSimpleVT());
// Keep legalizing the type.
MTy = LK.second;
Value *TargetLoweringBase::getDefaultSafeStackPointerLocation(IRBuilder<> &IRB,
bool UseTLS) const {
// compiler-rt provides a variable with a magic name. Targets that do not
// link with compiler-rt may also provide such a variable.
Module *M = IRB.GetInsertBlock()->getParent()->getParent();
const char *UnsafeStackPtrVar = "__safestack_unsafe_stack_ptr";
auto UnsafeStackPtr =
Type *StackPtrTy = Type::getInt8PtrTy(M->getContext());
if (!UnsafeStackPtr) {
auto TLSModel = UseTLS ?
GlobalValue::InitialExecTLSModel :
// The global variable is not defined yet, define it ourselves.
// We use the initial-exec TLS model because we do not support the
// variable living anywhere other than in the main executable.
UnsafeStackPtr = new GlobalVariable(
*M, StackPtrTy, false, GlobalValue::ExternalLinkage, nullptr,
UnsafeStackPtrVar, nullptr, TLSModel);
} else {
// The variable exists, check its type and attributes.
if (UnsafeStackPtr->getValueType() != StackPtrTy)
report_fatal_error(Twine(UnsafeStackPtrVar) + " must have void* type");
if (UseTLS != UnsafeStackPtr->isThreadLocal())
report_fatal_error(Twine(UnsafeStackPtrVar) + " must " +
(UseTLS ? "" : "not ") + "be thread-local");
return UnsafeStackPtr;
Value *TargetLoweringBase::getSafeStackPointerLocation(IRBuilder<> &IRB) const {
if (!TM.getTargetTriple().isAndroid())
return getDefaultSafeStackPointerLocation(IRB, true);
// Android provides a libc function to retrieve the address of the current
// thread's unsafe stack pointer.
Module *M = IRB.GetInsertBlock()->getParent()->getParent();
Type *StackPtrTy = Type::getInt8PtrTy(M->getContext());
FunctionCallee Fn = M->getOrInsertFunction("__safestack_pointer_address",
return IRB.CreateCall(Fn);
// Loop Strength Reduction hooks
/// isLegalAddressingMode - Return true if the addressing mode represented
/// by AM is legal for this target, for a load/store of the specified type.
bool TargetLoweringBase::isLegalAddressingMode(const DataLayout &DL,
const AddrMode &AM, Type *Ty,
unsigned AS, Instruction *I) const {
// The default implementation of this implements a conservative RISCy, r+r and
// r+i addr mode.
// Allows a sign-extended 16-bit immediate field.
if (AM.BaseOffs <= -(1LL << 16) || AM.BaseOffs >= (1LL << 16)-1)
return false;
// No global is ever allowed as a base.
if (AM.BaseGV)
return false;
// Only support r+r,
switch (AM.Scale) {
case 0: // "r+i" or just "i", depending on HasBaseReg.
case 1:
if (AM.HasBaseReg && AM.BaseOffs) // "r+r+i" is not allowed.
return false;
// Otherwise we have r+r or r+i.
case 2:
if (AM.HasBaseReg || AM.BaseOffs) // 2*r+r or 2*r+i is not allowed.
return false;
// Allow 2*r as r+r.
default: // Don't allow n * r
return false;
return true;
// Stack Protector
// For OpenBSD return its special guard variable. Otherwise return nullptr,
// so that SelectionDAG handle SSP.
Value *TargetLoweringBase::getIRStackGuard(IRBuilder<> &IRB) const {
if (getTargetMachine().getTargetTriple().isOSOpenBSD()) {
Module &M = *IRB.GetInsertBlock()->getParent()->getParent();
PointerType *PtrTy = Type::getInt8PtrTy(M.getContext());
Constant *C = M.getOrInsertGlobal("__guard_local", PtrTy);
if (GlobalVariable *G = dyn_cast_or_null<GlobalVariable>(C))
return C;
return nullptr;
// Currently only support "standard" __stack_chk_guard.
// TODO: add LOAD_STACK_GUARD support.
void TargetLoweringBase::insertSSPDeclarations(Module &M) const {
if (!M.getNamedValue("__stack_chk_guard")) {
auto *GV = new GlobalVariable(M, Type::getInt8PtrTy(M.getContext()), false,
GlobalVariable::ExternalLinkage, nullptr,
if (TM.getRelocationModel() == Reloc::Static &&
// Currently only support "standard" __stack_chk_guard.
// TODO: add LOAD_STACK_GUARD support.
Value *TargetLoweringBase::getSDagStackGuard(const Module &M) const {
return M.getNamedValue("__stack_chk_guard");
Function *TargetLoweringBase::getSSPStackGuardCheck(const Module &M) const {
return nullptr;
unsigned TargetLoweringBase::getMinimumJumpTableEntries() const {
return MinimumJumpTableEntries;
void TargetLoweringBase::setMinimumJumpTableEntries(unsigned Val) {
MinimumJumpTableEntries = Val;
unsigned TargetLoweringBase::getMinimumJumpTableDensity(bool OptForSize) const {
return OptForSize ? OptsizeJumpTableDensity : JumpTableDensity;
unsigned TargetLoweringBase::getMaximumJumpTableSize() const {
return MaximumJumpTableSize;
void TargetLoweringBase::setMaximumJumpTableSize(unsigned Val) {
MaximumJumpTableSize = Val;
bool TargetLoweringBase::isJumpTableRelative() const {
return getTargetMachine().isPositionIndependent();
// Reciprocal Estimates
/// Get the reciprocal estimate attribute string for a function that will
/// override the target defaults.
static StringRef getRecipEstimateForFunc(MachineFunction &MF) {
const Function &F = MF.getFunction();
return F.getFnAttribute("reciprocal-estimates").getValueAsString();
/// Construct a string for the given reciprocal operation of the given type.
/// This string should match the corresponding option to the front-end's
/// "-mrecip" flag assuming those strings have been passed through in an
/// attribute string. For example, "vec-divf" for a division of a vXf32.
static std::string getReciprocalOpName(bool IsSqrt, EVT VT) {
std::string Name = VT.isVector() ? "vec-" : "";
Name += IsSqrt ? "sqrt" : "div";
// TODO: Handle "half" or other float types?
if (VT.getScalarType() == MVT::f64) {
Name += "d";
} else {
assert(VT.getScalarType() == MVT::f32 &&
"Unexpected FP type for reciprocal estimate");
Name += "f";
return Name;
/// Return the character position and value (a single numeric character) of a
/// customized refinement operation in the input string if it exists. Return
/// false if there is no customized refinement step count.
static bool parseRefinementStep(StringRef In, size_t &Position,
uint8_t &Value) {
const char RefStepToken = ':';
Position = In.find(RefStepToken);
if (Position == StringRef::npos)
return false;
StringRef RefStepString = In.substr(Position + 1);
// Allow exactly one numeric character for the additional refinement
// step parameter.
if (RefStepString.size() == 1) {
char RefStepChar = RefStepString[0];
if (isDigit(RefStepChar)) {
Value = RefStepChar - '0';
return true;
report_fatal_error("Invalid refinement step for -recip.");
/// For the input attribute string, return one of the ReciprocalEstimate enum
/// status values (enabled, disabled, or not specified) for this operation on
/// the specified data type.
static int getOpEnabled(bool IsSqrt, EVT VT, StringRef Override) {
if (Override.empty())
return TargetLoweringBase::ReciprocalEstimate::Unspecified;
SmallVector<StringRef, 4> OverrideVector;
Override.split(OverrideVector, ',');
unsigned NumArgs = OverrideVector.size();
// Check if "all", "none", or "default" was specified.
if (NumArgs == 1) {
// Look for an optional setting of the number of refinement steps needed
// for this type of reciprocal operation.
size_t RefPos;
uint8_t RefSteps;
if (parseRefinementStep(Override, RefPos, RefSteps)) {
// Split the string for further processing.
Override = Override.substr(0, RefPos);
// All reciprocal types are enabled.
if (Override == "all")
return TargetLoweringBase::ReciprocalEstimate::Enabled;
// All reciprocal types are disabled.
if (Override == "none")
return TargetLoweringBase::ReciprocalEstimate::Disabled;
// Target defaults for enablement are used.
if (Override == "default")
return TargetLoweringBase::ReciprocalEstimate::Unspecified;
// The attribute string may omit the size suffix ('f'/'d').
std::string VTName = getReciprocalOpName(IsSqrt, VT);
std::string VTNameNoSize = VTName;
static const char DisabledPrefix = '!';
for (StringRef RecipType : OverrideVector) {
size_t RefPos;
uint8_t RefSteps;
if (parseRefinementStep(RecipType, RefPos, RefSteps))
RecipType = RecipType.substr(0, RefPos);
// Ignore the disablement token for string matching.
bool IsDisabled = RecipType[0] == DisabledPrefix;
if (IsDisabled)
RecipType = RecipType.substr(1);
if (RecipType.equals(VTName) || RecipType.equals(VTNameNoSize))
return IsDisabled ? TargetLoweringBase::ReciprocalEstimate::Disabled
: TargetLoweringBase::ReciprocalEstimate::Enabled;
return TargetLoweringBase::ReciprocalEstimate::Unspecified;
/// For the input attribute string, return the customized refinement step count
/// for this operation on the specified data type. If the step count does not
/// exist, return the ReciprocalEstimate enum value for unspecified.
static int getOpRefinementSteps(bool IsSqrt, EVT VT, StringRef Override) {
if (Override.empty())
return TargetLoweringBase::ReciprocalEstimate::Unspecified;
SmallVector<StringRef, 4> OverrideVector;
Override.split(OverrideVector, ',');
unsigned NumArgs = OverrideVector.size();
// Check if "all", "default", or "none" was specified.
if (NumArgs == 1) {
// Look for an optional setting of the number of refinement steps needed
// for this type of reciprocal operation.
size_t RefPos;
uint8_t RefSteps;
if (!parseRefinementStep(Override, RefPos, RefSteps))
return TargetLoweringBase::ReciprocalEstimate::Unspecified;
// Split the string for further processing.
Override = Override.substr(0, RefPos);
assert(Override != "none" &&
"Disabled reciprocals, but specifed refinement steps?");
// If this is a general override, return the specified number of steps.
if (Override == "all" || Override == "default")
return RefSteps;
// The attribute string may omit the size suffix ('f'/'d').
std::string VTName = getReciprocalOpName(IsSqrt, VT);
std::string VTNameNoSize = VTName;
for (StringRef RecipType : OverrideVector) {
size_t RefPos;
uint8_t RefSteps;
if (!parseRefinementStep(RecipType, RefPos, RefSteps))
RecipType = RecipType.substr(0, RefPos);
if (RecipType.equals(VTName) || RecipType.equals(VTNameNoSize))
return RefSteps;
return TargetLoweringBase::ReciprocalEstimate::Unspecified;
int TargetLoweringBase::getRecipEstimateSqrtEnabled(EVT VT,
MachineFunction &MF) const {
return getOpEnabled(true, VT, getRecipEstimateForFunc(MF));
int TargetLoweringBase::getRecipEstimateDivEnabled(EVT VT,
MachineFunction &MF) const {
return getOpEnabled(false, VT, getRecipEstimateForFunc(MF));
int TargetLoweringBase::getSqrtRefinementSteps(EVT VT,
MachineFunction &MF) const {
return getOpRefinementSteps(true, VT, getRecipEstimateForFunc(MF));
int TargetLoweringBase::getDivRefinementSteps(EVT VT,
MachineFunction &MF) const {
return getOpRefinementSteps(false, VT, getRecipEstimateForFunc(MF));
void TargetLoweringBase::finalizeLowering(MachineFunction &MF) const {
TargetLoweringBase::getLoadMemOperandFlags(const LoadInst &LI,
const DataLayout &DL) const {
MachineMemOperand::Flags Flags = MachineMemOperand::MOLoad;
if (LI.isVolatile())
Flags |= MachineMemOperand::MOVolatile;
if (LI.hasMetadata(LLVMContext::MD_nontemporal))
Flags |= MachineMemOperand::MONonTemporal;
if (LI.hasMetadata(LLVMContext::MD_invariant_load))
Flags |= MachineMemOperand::MOInvariant;
if (isDereferenceablePointer(LI.getPointerOperand(), LI.getType(), DL))
Flags |= MachineMemOperand::MODereferenceable;
Flags |= getTargetMMOFlags(LI);
return Flags;
TargetLoweringBase::getStoreMemOperandFlags(const StoreInst &SI,
const DataLayout &DL) const {
MachineMemOperand::Flags Flags = MachineMemOperand::MOStore;
if (SI.isVolatile())
Flags |= MachineMemOperand::MOVolatile;
if (SI.hasMetadata(LLVMContext::MD_nontemporal))
Flags |= MachineMemOperand::MONonTemporal;
// FIXME: Not preserving dereferenceable
Flags |= getTargetMMOFlags(SI);
return Flags;
TargetLoweringBase::getAtomicMemOperandFlags(const Instruction &AI,
const DataLayout &DL) const {
auto Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOStore;
if (const AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(&AI)) {
if (RMW->isVolatile())
Flags |= MachineMemOperand::MOVolatile;
} else if (const AtomicCmpXchgInst *CmpX = dyn_cast<AtomicCmpXchgInst>(&AI)) {
if (CmpX->isVolatile())
Flags |= MachineMemOperand::MOVolatile;
} else
llvm_unreachable("not an atomic instruction");
// FIXME: Not preserving dereferenceable
Flags |= getTargetMMOFlags(AI);
return Flags;
// GlobalISel Hooks
bool TargetLoweringBase::shouldLocalize(const MachineInstr &MI,
const TargetTransformInfo *TTI) const {
auto &MF = *MI.getMF();
auto &MRI = MF.getRegInfo();
// Assuming a spill and reload of a value has a cost of 1 instruction each,
// this helper function computes the maximum number of uses we should consider
// for remat. E.g. on arm64 global addresses take 2 insts to materialize. We
// break even in terms of code size when the original MI has 2 users vs
// choosing to potentially spill. Any more than 2 users we we have a net code
// size increase. This doesn't take into account register pressure though.
auto maxUses = [](unsigned RematCost) {
// A cost of 1 means remats are basically free.
if (RematCost == 1)
return UINT_MAX;
if (RematCost == 2)
return 2U;
// Remat is too expensive, only sink if there's one user.
if (RematCost > 2)
return 1U;
llvm_unreachable("Unexpected remat cost");
// Helper to walk through uses and terminate if we've reached a limit. Saves
// us spending time traversing uses if all we want to know is if it's >= min.
auto isUsesAtMost = [&](unsigned Reg, unsigned MaxUses) {
unsigned NumUses = 0;
auto UI = MRI.use_instr_nodbg_begin(Reg), UE = MRI.use_instr_nodbg_end();
for (; UI != UE && NumUses < MaxUses; ++UI) {
// If we haven't reached the end yet then there are more than MaxUses users.
return UI == UE;
switch (MI.getOpcode()) {
return false;
// Constants-like instructions should be close to their users.
// We don't want long live-ranges for them.
case TargetOpcode::G_CONSTANT:
case TargetOpcode::G_FCONSTANT:
case TargetOpcode::G_FRAME_INDEX:
case TargetOpcode::G_INTTOPTR:
return true;
case TargetOpcode::G_GLOBAL_VALUE: {
unsigned RematCost = TTI->getGISelRematGlobalCost();
Register Reg = MI.getOperand(0).getReg();
unsigned MaxUses = maxUses(RematCost);
if (MaxUses == UINT_MAX)
return true; // Remats are "free" so always localize.
bool B = isUsesAtMost(Reg, MaxUses);
return B;