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//===-- RISCVInstrInfo.cpp - RISCV Instruction Information ------*- 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
//
//===----------------------------------------------------------------------===//
//
// This file contains the RISCV implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "RISCVInstrInfo.h"
#include "MCTargetDesc/RISCVMatInt.h"
#include "RISCV.h"
#include "RISCVMachineFunctionInfo.h"
#include "RISCVSubtarget.h"
#include "RISCVTargetMachine.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Analysis/MemoryLocation.h"
#include "llvm/CodeGen/LiveIntervals.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/MachineCombinerPattern.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/MC/MCInstBuilder.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;
#define GEN_CHECK_COMPRESS_INSTR
#include "RISCVGenCompressInstEmitter.inc"
#define GET_INSTRINFO_CTOR_DTOR
#define GET_INSTRINFO_NAMED_OPS
#include "RISCVGenInstrInfo.inc"
static cl::opt<bool> PreferWholeRegisterMove(
"riscv-prefer-whole-register-move", cl::init(false), cl::Hidden,
cl::desc("Prefer whole register move for vector registers."));
namespace llvm::RISCVVPseudosTable {
using namespace RISCV;
#define GET_RISCVVPseudosTable_IMPL
#include "RISCVGenSearchableTables.inc"
} // namespace llvm::RISCVVPseudosTable
RISCVInstrInfo::RISCVInstrInfo(RISCVSubtarget &STI)
: RISCVGenInstrInfo(RISCV::ADJCALLSTACKDOWN, RISCV::ADJCALLSTACKUP),
STI(STI) {}
MCInst RISCVInstrInfo::getNop() const {
if (STI.hasStdExtCOrZca())
return MCInstBuilder(RISCV::C_NOP);
return MCInstBuilder(RISCV::ADDI)
.addReg(RISCV::X0)
.addReg(RISCV::X0)
.addImm(0);
}
unsigned RISCVInstrInfo::isLoadFromStackSlot(const MachineInstr &MI,
int &FrameIndex) const {
switch (MI.getOpcode()) {
default:
return 0;
case RISCV::LB:
case RISCV::LBU:
case RISCV::LH:
case RISCV::LHU:
case RISCV::FLH:
case RISCV::LW:
case RISCV::FLW:
case RISCV::LWU:
case RISCV::LD:
case RISCV::FLD:
break;
}
if (MI.getOperand(1).isFI() && MI.getOperand(2).isImm() &&
MI.getOperand(2).getImm() == 0) {
FrameIndex = MI.getOperand(1).getIndex();
return MI.getOperand(0).getReg();
}
return 0;
}
unsigned RISCVInstrInfo::isStoreToStackSlot(const MachineInstr &MI,
int &FrameIndex) const {
switch (MI.getOpcode()) {
default:
return 0;
case RISCV::SB:
case RISCV::SH:
case RISCV::SW:
case RISCV::FSH:
case RISCV::FSW:
case RISCV::SD:
case RISCV::FSD:
break;
}
if (MI.getOperand(1).isFI() && MI.getOperand(2).isImm() &&
MI.getOperand(2).getImm() == 0) {
FrameIndex = MI.getOperand(1).getIndex();
return MI.getOperand(0).getReg();
}
return 0;
}
static bool forwardCopyWillClobberTuple(unsigned DstReg, unsigned SrcReg,
unsigned NumRegs) {
return DstReg > SrcReg && (DstReg - SrcReg) < NumRegs;
}
static bool isConvertibleToVMV_V_V(const RISCVSubtarget &STI,
const MachineBasicBlock &MBB,
MachineBasicBlock::const_iterator MBBI,
MachineBasicBlock::const_iterator &DefMBBI,
RISCVII::VLMUL LMul) {
if (PreferWholeRegisterMove)
return false;
assert(MBBI->getOpcode() == TargetOpcode::COPY &&
"Unexpected COPY instruction.");
Register SrcReg = MBBI->getOperand(1).getReg();
const TargetRegisterInfo *TRI = STI.getRegisterInfo();
bool FoundDef = false;
bool FirstVSetVLI = false;
unsigned FirstSEW = 0;
while (MBBI != MBB.begin()) {
--MBBI;
if (MBBI->isMetaInstruction())
continue;
if (MBBI->getOpcode() == RISCV::PseudoVSETVLI ||
MBBI->getOpcode() == RISCV::PseudoVSETVLIX0 ||
MBBI->getOpcode() == RISCV::PseudoVSETIVLI) {
// There is a vsetvli between COPY and source define instruction.
// vy = def_vop ... (producing instruction)
// ...
// vsetvli
// ...
// vx = COPY vy
if (!FoundDef) {
if (!FirstVSetVLI) {
FirstVSetVLI = true;
unsigned FirstVType = MBBI->getOperand(2).getImm();
RISCVII::VLMUL FirstLMul = RISCVVType::getVLMUL(FirstVType);
FirstSEW = RISCVVType::getSEW(FirstVType);
// The first encountered vsetvli must have the same lmul as the
// register class of COPY.
if (FirstLMul != LMul)
return false;
}
// Only permit `vsetvli x0, x0, vtype` between COPY and the source
// define instruction.
if (MBBI->getOperand(0).getReg() != RISCV::X0)
return false;
if (MBBI->getOperand(1).isImm())
return false;
if (MBBI->getOperand(1).getReg() != RISCV::X0)
return false;
continue;
}
// MBBI is the first vsetvli before the producing instruction.
unsigned VType = MBBI->getOperand(2).getImm();
// If there is a vsetvli between COPY and the producing instruction.
if (FirstVSetVLI) {
// If SEW is different, return false.
if (RISCVVType::getSEW(VType) != FirstSEW)
return false;
}
// If the vsetvli is tail undisturbed, keep the whole register move.
if (!RISCVVType::isTailAgnostic(VType))
return false;
// The checking is conservative. We only have register classes for
// LMUL = 1/2/4/8. We should be able to convert vmv1r.v to vmv.v.v
// for fractional LMUL operations. However, we could not use the vsetvli
// lmul for widening operations. The result of widening operation is
// 2 x LMUL.
return LMul == RISCVVType::getVLMUL(VType);
} else if (MBBI->isInlineAsm() || MBBI->isCall()) {
return false;
} else if (MBBI->getNumDefs()) {
// Check all the instructions which will change VL.
// For example, vleff has implicit def VL.
if (MBBI->modifiesRegister(RISCV::VL))
return false;
// Only converting whole register copies to vmv.v.v when the defining
// value appears in the explicit operands.
for (const MachineOperand &MO : MBBI->explicit_operands()) {
if (!MO.isReg() || !MO.isDef())
continue;
if (!FoundDef && TRI->isSubRegisterEq(MO.getReg(), SrcReg)) {
// We only permit the source of COPY has the same LMUL as the defined
// operand.
// There are cases we need to keep the whole register copy if the LMUL
// is different.
// For example,
// $x0 = PseudoVSETIVLI 4, 73 // vsetivli zero, 4, e16,m2,ta,m
// $v28m4 = PseudoVWADD_VV_M2 $v26m2, $v8m2
// # The COPY may be created by vlmul_trunc intrinsic.
// $v26m2 = COPY renamable $v28m2, implicit killed $v28m4
//
// After widening, the valid value will be 4 x e32 elements. If we
// convert the COPY to vmv.v.v, it will only copy 4 x e16 elements.
// FIXME: The COPY of subregister of Zvlsseg register will not be able
// to convert to vmv.v.[v|i] under the constraint.
if (MO.getReg() != SrcReg)
return false;
// In widening reduction instructions with LMUL_1 input vector case,
// only checking the LMUL is insufficient due to reduction result is
// always LMUL_1.
// For example,
// $x11 = PseudoVSETIVLI 1, 64 // vsetivli a1, 1, e8, m1, ta, mu
// $v8m1 = PseudoVWREDSUM_VS_M1 $v26, $v27
// $v26 = COPY killed renamable $v8
// After widening, The valid value will be 1 x e16 elements. If we
// convert the COPY to vmv.v.v, it will only copy 1 x e8 elements.
uint64_t TSFlags = MBBI->getDesc().TSFlags;
if (RISCVII::isRVVWideningReduction(TSFlags))
return false;
// If the producing instruction does not depend on vsetvli, do not
// convert COPY to vmv.v.v. For example, VL1R_V or PseudoVRELOAD.
if (!RISCVII::hasSEWOp(TSFlags) || !RISCVII::hasVLOp(TSFlags))
return false;
// Found the definition.
FoundDef = true;
DefMBBI = MBBI;
break;
}
}
}
}
return false;
}
void RISCVInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
const DebugLoc &DL, MCRegister DstReg,
MCRegister SrcReg, bool KillSrc) const {
if (RISCV::GPRRegClass.contains(DstReg, SrcReg)) {
BuildMI(MBB, MBBI, DL, get(RISCV::ADDI), DstReg)
.addReg(SrcReg, getKillRegState(KillSrc))
.addImm(0);
return;
}
// Handle copy from csr
if (RISCV::VCSRRegClass.contains(SrcReg) &&
RISCV::GPRRegClass.contains(DstReg)) {
const TargetRegisterInfo &TRI = *STI.getRegisterInfo();
BuildMI(MBB, MBBI, DL, get(RISCV::CSRRS), DstReg)
.addImm(RISCVSysReg::lookupSysRegByName(TRI.getName(SrcReg))->Encoding)
.addReg(RISCV::X0);
return;
}
// FPR->FPR copies and VR->VR copies.
unsigned Opc;
bool IsScalableVector = true;
unsigned NF = 1;
RISCVII::VLMUL LMul = RISCVII::LMUL_1;
unsigned SubRegIdx = RISCV::sub_vrm1_0;
if (RISCV::FPR16RegClass.contains(DstReg, SrcReg)) {
if (!STI.hasStdExtZfh() && STI.hasStdExtZfhmin()) {
// Zfhmin subset doesn't have FSGNJ_H, replaces FSGNJ_H with FSGNJ_S.
const TargetRegisterInfo *TRI = STI.getRegisterInfo();
DstReg = TRI->getMatchingSuperReg(DstReg, RISCV::sub_16,
&RISCV::FPR32RegClass);
SrcReg = TRI->getMatchingSuperReg(SrcReg, RISCV::sub_16,
&RISCV::FPR32RegClass);
Opc = RISCV::FSGNJ_S;
} else {
Opc = RISCV::FSGNJ_H;
}
IsScalableVector = false;
} else if (RISCV::FPR32RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::FSGNJ_S;
IsScalableVector = false;
} else if (RISCV::FPR64RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::FSGNJ_D;
IsScalableVector = false;
} else if (RISCV::VRRegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::VMV1R_V;
LMul = RISCVII::LMUL_1;
} else if (RISCV::VRM2RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::VMV2R_V;
LMul = RISCVII::LMUL_2;
} else if (RISCV::VRM4RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::VMV4R_V;
LMul = RISCVII::LMUL_4;
} else if (RISCV::VRM8RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::VMV8R_V;
LMul = RISCVII::LMUL_8;
} else if (RISCV::VRN2M1RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::VMV1R_V;
SubRegIdx = RISCV::sub_vrm1_0;
NF = 2;
LMul = RISCVII::LMUL_1;
} else if (RISCV::VRN2M2RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::VMV2R_V;
SubRegIdx = RISCV::sub_vrm2_0;
NF = 2;
LMul = RISCVII::LMUL_2;
} else if (RISCV::VRN2M4RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::VMV4R_V;
SubRegIdx = RISCV::sub_vrm4_0;
NF = 2;
LMul = RISCVII::LMUL_4;
} else if (RISCV::VRN3M1RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::VMV1R_V;
SubRegIdx = RISCV::sub_vrm1_0;
NF = 3;
LMul = RISCVII::LMUL_1;
} else if (RISCV::VRN3M2RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::VMV2R_V;
SubRegIdx = RISCV::sub_vrm2_0;
NF = 3;
LMul = RISCVII::LMUL_2;
} else if (RISCV::VRN4M1RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::VMV1R_V;
SubRegIdx = RISCV::sub_vrm1_0;
NF = 4;
LMul = RISCVII::LMUL_1;
} else if (RISCV::VRN4M2RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::VMV2R_V;
SubRegIdx = RISCV::sub_vrm2_0;
NF = 4;
LMul = RISCVII::LMUL_2;
} else if (RISCV::VRN5M1RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::VMV1R_V;
SubRegIdx = RISCV::sub_vrm1_0;
NF = 5;
LMul = RISCVII::LMUL_1;
} else if (RISCV::VRN6M1RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::VMV1R_V;
SubRegIdx = RISCV::sub_vrm1_0;
NF = 6;
LMul = RISCVII::LMUL_1;
} else if (RISCV::VRN7M1RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::VMV1R_V;
SubRegIdx = RISCV::sub_vrm1_0;
NF = 7;
LMul = RISCVII::LMUL_1;
} else if (RISCV::VRN8M1RegClass.contains(DstReg, SrcReg)) {
Opc = RISCV::VMV1R_V;
SubRegIdx = RISCV::sub_vrm1_0;
NF = 8;
LMul = RISCVII::LMUL_1;
} else {
llvm_unreachable("Impossible reg-to-reg copy");
}
if (IsScalableVector) {
bool UseVMV_V_V = false;
MachineBasicBlock::const_iterator DefMBBI;
unsigned VIOpc;
if (isConvertibleToVMV_V_V(STI, MBB, MBBI, DefMBBI, LMul)) {
UseVMV_V_V = true;
// We only need to handle LMUL = 1/2/4/8 here because we only define
// vector register classes for LMUL = 1/2/4/8.
switch (LMul) {
default:
llvm_unreachable("Impossible LMUL for vector register copy.");
case RISCVII::LMUL_1:
Opc = RISCV::PseudoVMV_V_V_M1;
VIOpc = RISCV::PseudoVMV_V_I_M1;
break;
case RISCVII::LMUL_2:
Opc = RISCV::PseudoVMV_V_V_M2;
VIOpc = RISCV::PseudoVMV_V_I_M2;
break;
case RISCVII::LMUL_4:
Opc = RISCV::PseudoVMV_V_V_M4;
VIOpc = RISCV::PseudoVMV_V_I_M4;
break;
case RISCVII::LMUL_8:
Opc = RISCV::PseudoVMV_V_V_M8;
VIOpc = RISCV::PseudoVMV_V_I_M8;
break;
}
}
bool UseVMV_V_I = false;
if (UseVMV_V_V && (DefMBBI->getOpcode() == VIOpc)) {
UseVMV_V_I = true;
Opc = VIOpc;
}
if (NF == 1) {
auto MIB = BuildMI(MBB, MBBI, DL, get(Opc), DstReg);
if (UseVMV_V_I)
MIB = MIB.add(DefMBBI->getOperand(1));
else
MIB = MIB.addReg(SrcReg, getKillRegState(KillSrc));
if (UseVMV_V_V) {
const MCInstrDesc &Desc = DefMBBI->getDesc();
MIB.add(DefMBBI->getOperand(RISCVII::getVLOpNum(Desc))); // AVL
MIB.add(DefMBBI->getOperand(RISCVII::getSEWOpNum(Desc))); // SEW
MIB.addReg(RISCV::VL, RegState::Implicit);
MIB.addReg(RISCV::VTYPE, RegState::Implicit);
}
} else {
const TargetRegisterInfo *TRI = STI.getRegisterInfo();
int I = 0, End = NF, Incr = 1;
unsigned SrcEncoding = TRI->getEncodingValue(SrcReg);
unsigned DstEncoding = TRI->getEncodingValue(DstReg);
unsigned LMulVal;
bool Fractional;
std::tie(LMulVal, Fractional) = RISCVVType::decodeVLMUL(LMul);
assert(!Fractional && "It is impossible be fractional lmul here.");
if (forwardCopyWillClobberTuple(DstEncoding, SrcEncoding, NF * LMulVal)) {
I = NF - 1;
End = -1;
Incr = -1;
}
for (; I != End; I += Incr) {
auto MIB = BuildMI(MBB, MBBI, DL, get(Opc),
TRI->getSubReg(DstReg, SubRegIdx + I));
if (UseVMV_V_I)
MIB = MIB.add(DefMBBI->getOperand(1));
else
MIB = MIB.addReg(TRI->getSubReg(SrcReg, SubRegIdx + I),
getKillRegState(KillSrc));
if (UseVMV_V_V) {
const MCInstrDesc &Desc = DefMBBI->getDesc();
MIB.add(DefMBBI->getOperand(RISCVII::getVLOpNum(Desc))); // AVL
MIB.add(DefMBBI->getOperand(RISCVII::getSEWOpNum(Desc))); // SEW
MIB.addReg(RISCV::VL, RegState::Implicit);
MIB.addReg(RISCV::VTYPE, RegState::Implicit);
}
}
}
} else {
BuildMI(MBB, MBBI, DL, get(Opc), DstReg)
.addReg(SrcReg, getKillRegState(KillSrc))
.addReg(SrcReg, getKillRegState(KillSrc));
}
}
void RISCVInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
Register SrcReg, bool IsKill, int FI,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI,
Register VReg) const {
DebugLoc DL;
if (I != MBB.end())
DL = I->getDebugLoc();
MachineFunction *MF = MBB.getParent();
MachineFrameInfo &MFI = MF->getFrameInfo();
unsigned Opcode;
bool IsScalableVector = true;
if (RISCV::GPRRegClass.hasSubClassEq(RC)) {
Opcode = TRI->getRegSizeInBits(RISCV::GPRRegClass) == 32 ?
RISCV::SW : RISCV::SD;
IsScalableVector = false;
} else if (RISCV::FPR16RegClass.hasSubClassEq(RC)) {
Opcode = RISCV::FSH;
IsScalableVector = false;
} else if (RISCV::FPR32RegClass.hasSubClassEq(RC)) {
Opcode = RISCV::FSW;
IsScalableVector = false;
} else if (RISCV::FPR64RegClass.hasSubClassEq(RC)) {
Opcode = RISCV::FSD;
IsScalableVector = false;
} else if (RISCV::VRRegClass.hasSubClassEq(RC)) {
Opcode = RISCV::VS1R_V;
} else if (RISCV::VRM2RegClass.hasSubClassEq(RC)) {
Opcode = RISCV::VS2R_V;
} else if (RISCV::VRM4RegClass.hasSubClassEq(RC)) {
Opcode = RISCV::VS4R_V;
} else if (RISCV::VRM8RegClass.hasSubClassEq(RC)) {
Opcode = RISCV::VS8R_V;
} else if (RISCV::VRN2M1RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVSPILL2_M1;
else if (RISCV::VRN2M2RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVSPILL2_M2;
else if (RISCV::VRN2M4RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVSPILL2_M4;
else if (RISCV::VRN3M1RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVSPILL3_M1;
else if (RISCV::VRN3M2RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVSPILL3_M2;
else if (RISCV::VRN4M1RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVSPILL4_M1;
else if (RISCV::VRN4M2RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVSPILL4_M2;
else if (RISCV::VRN5M1RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVSPILL5_M1;
else if (RISCV::VRN6M1RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVSPILL6_M1;
else if (RISCV::VRN7M1RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVSPILL7_M1;
else if (RISCV::VRN8M1RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVSPILL8_M1;
else
llvm_unreachable("Can't store this register to stack slot");
if (IsScalableVector) {
MachineMemOperand *MMO = MF->getMachineMemOperand(
MachinePointerInfo::getFixedStack(*MF, FI), MachineMemOperand::MOStore,
MemoryLocation::UnknownSize, MFI.getObjectAlign(FI));
MFI.setStackID(FI, TargetStackID::ScalableVector);
BuildMI(MBB, I, DL, get(Opcode))
.addReg(SrcReg, getKillRegState(IsKill))
.addFrameIndex(FI)
.addMemOperand(MMO);
} else {
MachineMemOperand *MMO = MF->getMachineMemOperand(
MachinePointerInfo::getFixedStack(*MF, FI), MachineMemOperand::MOStore,
MFI.getObjectSize(FI), MFI.getObjectAlign(FI));
BuildMI(MBB, I, DL, get(Opcode))
.addReg(SrcReg, getKillRegState(IsKill))
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO);
}
}
void RISCVInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
Register DstReg, int FI,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI,
Register VReg) const {
DebugLoc DL;
if (I != MBB.end())
DL = I->getDebugLoc();
MachineFunction *MF = MBB.getParent();
MachineFrameInfo &MFI = MF->getFrameInfo();
unsigned Opcode;
bool IsScalableVector = true;
if (RISCV::GPRRegClass.hasSubClassEq(RC)) {
Opcode = TRI->getRegSizeInBits(RISCV::GPRRegClass) == 32 ?
RISCV::LW : RISCV::LD;
IsScalableVector = false;
} else if (RISCV::FPR16RegClass.hasSubClassEq(RC)) {
Opcode = RISCV::FLH;
IsScalableVector = false;
} else if (RISCV::FPR32RegClass.hasSubClassEq(RC)) {
Opcode = RISCV::FLW;
IsScalableVector = false;
} else if (RISCV::FPR64RegClass.hasSubClassEq(RC)) {
Opcode = RISCV::FLD;
IsScalableVector = false;
} else if (RISCV::VRRegClass.hasSubClassEq(RC)) {
Opcode = RISCV::VL1RE8_V;
} else if (RISCV::VRM2RegClass.hasSubClassEq(RC)) {
Opcode = RISCV::VL2RE8_V;
} else if (RISCV::VRM4RegClass.hasSubClassEq(RC)) {
Opcode = RISCV::VL4RE8_V;
} else if (RISCV::VRM8RegClass.hasSubClassEq(RC)) {
Opcode = RISCV::VL8RE8_V;
} else if (RISCV::VRN2M1RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVRELOAD2_M1;
else if (RISCV::VRN2M2RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVRELOAD2_M2;
else if (RISCV::VRN2M4RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVRELOAD2_M4;
else if (RISCV::VRN3M1RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVRELOAD3_M1;
else if (RISCV::VRN3M2RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVRELOAD3_M2;
else if (RISCV::VRN4M1RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVRELOAD4_M1;
else if (RISCV::VRN4M2RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVRELOAD4_M2;
else if (RISCV::VRN5M1RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVRELOAD5_M1;
else if (RISCV::VRN6M1RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVRELOAD6_M1;
else if (RISCV::VRN7M1RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVRELOAD7_M1;
else if (RISCV::VRN8M1RegClass.hasSubClassEq(RC))
Opcode = RISCV::PseudoVRELOAD8_M1;
else
llvm_unreachable("Can't load this register from stack slot");
if (IsScalableVector) {
MachineMemOperand *MMO = MF->getMachineMemOperand(
MachinePointerInfo::getFixedStack(*MF, FI), MachineMemOperand::MOLoad,
MemoryLocation::UnknownSize, MFI.getObjectAlign(FI));
MFI.setStackID(FI, TargetStackID::ScalableVector);
BuildMI(MBB, I, DL, get(Opcode), DstReg)
.addFrameIndex(FI)
.addMemOperand(MMO);
} else {
MachineMemOperand *MMO = MF->getMachineMemOperand(
MachinePointerInfo::getFixedStack(*MF, FI), MachineMemOperand::MOLoad,
MFI.getObjectSize(FI), MFI.getObjectAlign(FI));
BuildMI(MBB, I, DL, get(Opcode), DstReg)
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO);
}
}
MachineInstr *RISCVInstrInfo::foldMemoryOperandImpl(
MachineFunction &MF, MachineInstr &MI, ArrayRef<unsigned> Ops,
MachineBasicBlock::iterator InsertPt, int FrameIndex, LiveIntervals *LIS,
VirtRegMap *VRM) const {
const MachineFrameInfo &MFI = MF.getFrameInfo();
// The below optimizations narrow the load so they are only valid for little
// endian.
// TODO: Support big endian by adding an offset into the frame object?
if (MF.getDataLayout().isBigEndian())
return nullptr;
// Fold load from stack followed by sext.w into lw.
// TODO: Fold with sext.b, sext.h, zext.b, zext.h, zext.w?
if (Ops.size() != 1 || Ops[0] != 1)
return nullptr;
unsigned LoadOpc;
switch (MI.getOpcode()) {
default:
if (RISCV::isSEXT_W(MI)) {
LoadOpc = RISCV::LW;
break;
}
if (RISCV::isZEXT_W(MI)) {
LoadOpc = RISCV::LWU;
break;
}
if (RISCV::isZEXT_B(MI)) {
LoadOpc = RISCV::LBU;
break;
}
return nullptr;
case RISCV::SEXT_H:
LoadOpc = RISCV::LH;
break;
case RISCV::SEXT_B:
LoadOpc = RISCV::LB;
break;
case RISCV::ZEXT_H_RV32:
case RISCV::ZEXT_H_RV64:
LoadOpc = RISCV::LHU;
break;
}
MachineMemOperand *MMO = MF.getMachineMemOperand(
MachinePointerInfo::getFixedStack(MF, FrameIndex),
MachineMemOperand::MOLoad, MFI.getObjectSize(FrameIndex),
MFI.getObjectAlign(FrameIndex));
Register DstReg = MI.getOperand(0).getReg();
return BuildMI(*MI.getParent(), InsertPt, MI.getDebugLoc(), get(LoadOpc),
DstReg)
.addFrameIndex(FrameIndex)
.addImm(0)
.addMemOperand(MMO);
}
void RISCVInstrInfo::movImm(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
const DebugLoc &DL, Register DstReg, uint64_t Val,
MachineInstr::MIFlag Flag) const {
Register SrcReg = RISCV::X0;
if (!STI.is64Bit() && !isInt<32>(Val))
report_fatal_error("Should only materialize 32-bit constants for RV32");
RISCVMatInt::InstSeq Seq =
RISCVMatInt::generateInstSeq(Val, STI.getFeatureBits());
assert(!Seq.empty());
for (RISCVMatInt::Inst &Inst : Seq) {
switch (Inst.getOpndKind()) {
case RISCVMatInt::Imm:
BuildMI(MBB, MBBI, DL, get(Inst.getOpcode()), DstReg)
.addImm(Inst.getImm())
.setMIFlag(Flag);
break;
case RISCVMatInt::RegX0:
BuildMI(MBB, MBBI, DL, get(Inst.getOpcode()), DstReg)
.addReg(SrcReg, RegState::Kill)
.addReg(RISCV::X0)
.setMIFlag(Flag);
break;
case RISCVMatInt::RegReg:
BuildMI(MBB, MBBI, DL, get(Inst.getOpcode()), DstReg)
.addReg(SrcReg, RegState::Kill)
.addReg(SrcReg, RegState::Kill)
.setMIFlag(Flag);
break;
case RISCVMatInt::RegImm:
BuildMI(MBB, MBBI, DL, get(Inst.getOpcode()), DstReg)
.addReg(SrcReg, RegState::Kill)
.addImm(Inst.getImm())
.setMIFlag(Flag);
break;
}
// Only the first instruction has X0 as its source.
SrcReg = DstReg;
}
}
static RISCVCC::CondCode getCondFromBranchOpc(unsigned Opc) {
switch (Opc) {
default:
return RISCVCC::COND_INVALID;
case RISCV::BEQ:
return RISCVCC::COND_EQ;
case RISCV::BNE:
return RISCVCC::COND_NE;
case RISCV::BLT:
return RISCVCC::COND_LT;
case RISCV::BGE:
return RISCVCC::COND_GE;
case RISCV::BLTU:
return RISCVCC::COND_LTU;
case RISCV::BGEU:
return RISCVCC::COND_GEU;
}
}
// The contents of values added to Cond are not examined outside of
// RISCVInstrInfo, giving us flexibility in what to push to it. For RISCV, we
// push BranchOpcode, Reg1, Reg2.
static void parseCondBranch(MachineInstr &LastInst, MachineBasicBlock *&Target,
SmallVectorImpl<MachineOperand> &Cond) {
// Block ends with fall-through condbranch.
assert(LastInst.getDesc().isConditionalBranch() &&
"Unknown conditional branch");
Target = LastInst.getOperand(2).getMBB();
unsigned CC = getCondFromBranchOpc(LastInst.getOpcode());
Cond.push_back(MachineOperand::CreateImm(CC));
Cond.push_back(LastInst.getOperand(0));
Cond.push_back(LastInst.getOperand(1));
}
const MCInstrDesc &RISCVInstrInfo::getBrCond(RISCVCC::CondCode CC) const {
switch (CC) {
default:
llvm_unreachable("Unknown condition code!");
case RISCVCC::COND_EQ:
return get(RISCV::BEQ);
case RISCVCC::COND_NE:
return get(RISCV::BNE);
case RISCVCC::COND_LT:
return get(RISCV::BLT);
case RISCVCC::COND_GE:
return get(RISCV::BGE);
case RISCVCC::COND_LTU:
return get(RISCV::BLTU);
case RISCVCC::COND_GEU:
return get(RISCV::BGEU);
}
}
RISCVCC::CondCode RISCVCC::getOppositeBranchCondition(RISCVCC::CondCode CC) {
switch (CC) {
default:
llvm_unreachable("Unrecognized conditional branch");
case RISCVCC::COND_EQ:
return RISCVCC::COND_NE;
case RISCVCC::COND_NE:
return RISCVCC::COND_EQ;
case RISCVCC::COND_LT:
return RISCVCC::COND_GE;
case RISCVCC::COND_GE:
return RISCVCC::COND_LT;
case RISCVCC::COND_LTU:
return RISCVCC::COND_GEU;
case RISCVCC::COND_GEU:
return RISCVCC::COND_LTU;
}
}
bool RISCVInstrInfo::analyzeBranch(MachineBasicBlock &MBB,
MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const {
TBB = FBB = nullptr;
Cond.clear();
// If the block has no terminators, it just falls into the block after it.
MachineBasicBlock::iterator I = MBB.getLastNonDebugInstr();
if (I == MBB.end() || !isUnpredicatedTerminator(*I))
return false;
// Count the number of terminators and find the first unconditional or
// indirect branch.
MachineBasicBlock::iterator FirstUncondOrIndirectBr = MBB.end();
int NumTerminators = 0;
for (auto J = I.getReverse(); J != MBB.rend() && isUnpredicatedTerminator(*J);
J++) {
NumTerminators++;
if (J->getDesc().isUnconditionalBranch() ||
J->getDesc().isIndirectBranch()) {
FirstUncondOrIndirectBr = J.getReverse();
}
}
// If AllowModify is true, we can erase any terminators after
// FirstUncondOrIndirectBR.
if (AllowModify && FirstUncondOrIndirectBr != MBB.end()) {
while (std::next(FirstUncondOrIndirectBr) != MBB.end()) {
std::next(FirstUncondOrIndirectBr)->eraseFromParent();
NumTerminators--;
}
I = FirstUncondOrIndirectBr;
}
// We can't handle blocks that end in an indirect branch.
if (I->getDesc().isIndirectBranch())
return true;
// We can't handle blocks with more than 2 terminators.
if (NumTerminators > 2)
return true;
// Handle a single unconditional branch.
if (NumTerminators == 1 && I->getDesc().isUnconditionalBranch()) {
TBB = getBranchDestBlock(*I);
return false;
}
// Handle a single conditional branch.
if (NumTerminators == 1 && I->getDesc().isConditionalBranch()) {
parseCondBranch(*I, TBB, Cond);
return false;
}
// Handle a conditional branch followed by an unconditional branch.
if (NumTerminators == 2 && std::prev(I)->getDesc().isConditionalBranch() &&
I->getDesc().isUnconditionalBranch()) {
parseCondBranch(*std::prev(I), TBB, Cond);
FBB = getBranchDestBlock(*I);
return false;
}
// Otherwise, we can't handle this.
return true;
}
unsigned RISCVInstrInfo::removeBranch(MachineBasicBlock &MBB,
int *BytesRemoved) const {
if (BytesRemoved)
*BytesRemoved = 0;
MachineBasicBlock::iterator I = MBB.getLastNonDebugInstr();
if (I == MBB.end())
return 0;
if (!I->getDesc().isUnconditionalBranch() &&
!I->getDesc().isConditionalBranch())
return 0;
// Remove the branch.
if (BytesRemoved)
*BytesRemoved += getInstSizeInBytes(*I);
I->eraseFromParent();
I = MBB.end();
if (I == MBB.begin())
return 1;
--I;
if (!I->getDesc().isConditionalBranch())
return 1;
// Remove the branch.
if (BytesRemoved)
*BytesRemoved += getInstSizeInBytes(*I);
I->eraseFromParent();
return 2;
}
// Inserts a branch into the end of the specific MachineBasicBlock, returning
// the number of instructions inserted.
unsigned RISCVInstrInfo::insertBranch(
MachineBasicBlock &MBB, MachineBasicBlock *TBB, MachineBasicBlock *FBB,
ArrayRef<MachineOperand> Cond, const DebugLoc &DL, int *BytesAdded) const {
if (BytesAdded)
*BytesAdded = 0;
// Shouldn't be a fall through.
assert(TBB && "insertBranch must not be told to insert a fallthrough");
assert((Cond.size() == 3 || Cond.size() == 0) &&
"RISCV branch conditions have two components!");
// Unconditional branch.
if (Cond.empty()) {
MachineInstr &MI = *BuildMI(&MBB, DL, get(RISCV::PseudoBR)).addMBB(TBB);
if (BytesAdded)
*BytesAdded += getInstSizeInBytes(MI);
return 1;
}
// Either a one or two-way conditional branch.
auto CC = static_cast<RISCVCC::CondCode>(Cond[0].getImm());
MachineInstr &CondMI =
*BuildMI(&MBB, DL, getBrCond(CC)).add(Cond[1]).add(Cond[2]).addMBB(TBB);
if (BytesAdded)
*BytesAdded += getInstSizeInBytes(CondMI);
// One-way conditional branch.
if (!FBB)
return 1;
// Two-way conditional branch.
MachineInstr &MI = *BuildMI(&MBB, DL, get(RISCV::PseudoBR)).addMBB(FBB);
if (BytesAdded)
*BytesAdded += getInstSizeInBytes(MI);
return 2;
}
void RISCVInstrInfo::insertIndirectBranch(MachineBasicBlock &MBB,
MachineBasicBlock &DestBB,
MachineBasicBlock &RestoreBB,
const DebugLoc &DL, int64_t BrOffset,
RegScavenger *RS) const {
assert(RS && "RegScavenger required for long branching");
assert(MBB.empty() &&
"new block should be inserted for expanding unconditional branch");
assert(MBB.pred_size() == 1);
assert(RestoreBB.empty() &&
"restore block should be inserted for restoring clobbered registers");
MachineFunction *MF = MBB.getParent();
MachineRegisterInfo &MRI = MF->getRegInfo();
RISCVMachineFunctionInfo *RVFI = MF->getInfo<RISCVMachineFunctionInfo>();
const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
if (!isInt<32>(BrOffset))
report_fatal_error(
"Branch offsets outside of the signed 32-bit range not supported");
// FIXME: A virtual register must be used initially, as the register
// scavenger won't work with empty blocks (SIInstrInfo::insertIndirectBranch
// uses the same workaround).
Register ScratchReg = MRI.createVirtualRegister(&RISCV::GPRRegClass);
auto II = MBB.end();
// We may also update the jump target to RestoreBB later.
MachineInstr &MI = *BuildMI(MBB, II, DL, get(RISCV::PseudoJump))
.addReg(ScratchReg, RegState::Define | RegState::Dead)
.addMBB(&DestBB, RISCVII::MO_CALL);
RS->enterBasicBlockEnd(MBB);
Register TmpGPR =
RS->scavengeRegisterBackwards(RISCV::GPRRegClass, MI.getIterator(),
/*RestoreAfter=*/false, /*SpAdj=*/0,
/*AllowSpill=*/false);
if (TmpGPR != RISCV::NoRegister)
RS->setRegUsed(TmpGPR);
else {
// The case when there is no scavenged register needs special handling.
// Pick s11 because it doesn't make a difference.
TmpGPR = RISCV::X27;
int FrameIndex = RVFI->getBranchRelaxationScratchFrameIndex();
if (FrameIndex == -1)
report_fatal_error("underestimated function size");
storeRegToStackSlot(MBB, MI, TmpGPR, /*IsKill=*/true, FrameIndex,
&RISCV::GPRRegClass, TRI, Register());
TRI->eliminateFrameIndex(std::prev(MI.getIterator()),
/*SpAdj=*/0, /*FIOperandNum=*/1);
MI.getOperand(1).setMBB(&RestoreBB);
loadRegFromStackSlot(RestoreBB, RestoreBB.end(), TmpGPR, FrameIndex,
&RISCV::GPRRegClass, TRI, Register());
TRI->eliminateFrameIndex(RestoreBB.back(),
/*SpAdj=*/0, /*FIOperandNum=*/1);
}
MRI.replaceRegWith(ScratchReg, TmpGPR);
MRI.clearVirtRegs();
}
bool RISCVInstrInfo::reverseBranchCondition(
SmallVectorImpl<MachineOperand> &Cond) const {
assert((Cond.size() == 3) && "Invalid branch condition!");
auto CC = static_cast<RISCVCC::CondCode>(Cond[0].getImm());
Cond[0].setImm(getOppositeBranchCondition(CC));
return false;
}
MachineBasicBlock *
RISCVInstrInfo::getBranchDestBlock(const MachineInstr &MI) const {
assert(MI.getDesc().isBranch() && "Unexpected opcode!");
// The branch target is always the last operand.
int NumOp = MI.getNumExplicitOperands();
return MI.getOperand(NumOp - 1).getMBB();
}
bool RISCVInstrInfo::isBranchOffsetInRange(unsigned BranchOp,
int64_t BrOffset) const {
unsigned XLen = STI.getXLen();
// Ideally we could determine the supported branch offset from the
// RISCVII::FormMask, but this can't be used for Pseudo instructions like
// PseudoBR.
switch (BranchOp) {
default:
llvm_unreachable("Unexpected opcode!");
case RISCV::BEQ:
case RISCV::BNE:
case RISCV::BLT:
case RISCV::BGE:
case RISCV::BLTU:
case RISCV::BGEU:
return isIntN(13, BrOffset);
case RISCV::JAL:
case RISCV::PseudoBR:
return isIntN(21, BrOffset);
case RISCV::PseudoJump:
return isIntN(32, SignExtend64(BrOffset + 0x800, XLen));
}
}
// If the operation has a predicated pseudo instruction, return the pseudo
// instruction opcode. Otherwise, return RISCV::INSTRUCTION_LIST_END.
// TODO: Support more operations.
unsigned getPredicatedOpcode(unsigned Opcode) {
switch (Opcode) {
case RISCV::ADD: return RISCV::PseudoCCADD; break;
case RISCV::SUB: return RISCV::PseudoCCSUB; break;
case RISCV::AND: return RISCV::PseudoCCAND; break;
case RISCV::OR: return RISCV::PseudoCCOR; break;
case RISCV::XOR: return RISCV::PseudoCCXOR; break;
case RISCV::ADDW: return RISCV::PseudoCCADDW; break;
case RISCV::SUBW: return RISCV::PseudoCCSUBW; break;
}
return RISCV::INSTRUCTION_LIST_END;
}
/// Identify instructions that can be folded into a CCMOV instruction, and
/// return the defining instruction.
static MachineInstr *canFoldAsPredicatedOp(Register Reg,
const MachineRegisterInfo &MRI,
const TargetInstrInfo *TII) {
if (!Reg.isVirtual())
return nullptr;
if (!MRI.hasOneNonDBGUse(Reg))
return nullptr;
MachineInstr *MI = MRI.getVRegDef(Reg);
if (!MI)
return nullptr;
// Check if MI can be predicated and folded into the CCMOV.
if (getPredicatedOpcode(MI->getOpcode()) == RISCV::INSTRUCTION_LIST_END)
return nullptr;
// Check if MI has any other defs or physreg uses.
for (unsigned i = 1, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
// Reject frame index operands, PEI can't handle the predicated pseudos.
if (MO.isFI() || MO.isCPI() || MO.isJTI())
return nullptr;
if (!MO.isReg())
continue;
// MI can't have any tied operands, that would conflict with predication.
if (MO.isTied())
return nullptr;
if (MO.isDef())
return nullptr;
// Allow constant physregs.
if (MO.getReg().isPhysical() && !MRI.isConstantPhysReg(MO.getReg()))
return nullptr;
}
bool DontMoveAcrossStores = true;
if (!MI->isSafeToMove(/* AliasAnalysis = */ nullptr, DontMoveAcrossStores))
return nullptr;
return MI;
}
bool RISCVInstrInfo::analyzeSelect(const MachineInstr &MI,
SmallVectorImpl<MachineOperand> &Cond,
unsigned &TrueOp, unsigned &FalseOp,
bool &Optimizable) const {
assert(MI.getOpcode() == RISCV::PseudoCCMOVGPR &&
"Unknown select instruction");
// CCMOV operands:
// 0: Def.
// 1: LHS of compare.
// 2: RHS of compare.
// 3: Condition code.
// 4: False use.
// 5: True use.
TrueOp = 5;
FalseOp = 4;
Cond.push_back(MI.getOperand(1));
Cond.push_back(MI.getOperand(2));
Cond.push_back(MI.getOperand(3));
// We can only fold when we support short forward branch opt.
Optimizable = STI.hasShortForwardBranchOpt();
return false;
}
MachineInstr *
RISCVInstrInfo::optimizeSelect(MachineInstr &MI,
SmallPtrSetImpl<MachineInstr *> &SeenMIs,
bool PreferFalse) const {
assert(MI.getOpcode() == RISCV::PseudoCCMOVGPR &&
"Unknown select instruction");
if (!STI.hasShortForwardBranchOpt())
return nullptr;
MachineRegisterInfo &MRI = MI.getParent()->getParent()->getRegInfo();
MachineInstr *DefMI =
canFoldAsPredicatedOp(MI.getOperand(5).getReg(), MRI, this);
bool Invert = !DefMI;
if (!DefMI)
DefMI = canFoldAsPredicatedOp(MI.getOperand(4).getReg(), MRI, this);
if (!DefMI)
return nullptr;
// Find new register class to use.
MachineOperand FalseReg = MI.getOperand(Invert ? 5 : 4);
Register DestReg = MI.getOperand(0).getReg();
const TargetRegisterClass *PreviousClass = MRI.getRegClass(FalseReg.getReg());
if (!MRI.constrainRegClass(DestReg, PreviousClass))
return nullptr;
unsigned PredOpc = getPredicatedOpcode(DefMI->getOpcode());
assert(PredOpc != RISCV::INSTRUCTION_LIST_END && "Unexpected opcode!");
// Create a new predicated version of DefMI.
MachineInstrBuilder NewMI =
BuildMI(*MI.getParent(), MI, MI.getDebugLoc(), get(PredOpc), DestReg);
// Copy the condition portion.
NewMI.add(MI.getOperand(1));
NewMI.add(MI.getOperand(2));
// Add condition code, inverting if necessary.
auto CC = static_cast<RISCVCC::CondCode>(MI.getOperand(3).getImm());
if (Invert)
CC = RISCVCC::getOppositeBranchCondition(CC);
NewMI.addImm(CC);
// Copy the false register.
NewMI.add(FalseReg);
// Copy all the DefMI operands.
const MCInstrDesc &DefDesc = DefMI->getDesc();
for (unsigned i = 1, e = DefDesc.getNumOperands(); i != e; ++i)
NewMI.add(DefMI->getOperand(i));
// Update SeenMIs set: register newly created MI and erase removed DefMI.
SeenMIs.insert(NewMI);
SeenMIs.erase(DefMI);
// If MI is inside a loop, and DefMI is outside the loop, then kill flags on
// DefMI would be invalid when tranferred inside the loop. Checking for a
// loop is expensive, but at least remove kill flags if they are in different
// BBs.
if (DefMI->getParent() != MI.getParent())
NewMI->clearKillInfo();
// The caller will erase MI, but not DefMI.
DefMI->eraseFromParent();
return NewMI;
}
unsigned RISCVInstrInfo::getInstSizeInBytes(const MachineInstr &MI) const {
if (MI.isMetaInstruction())
return 0;
unsigned Opcode = MI.getOpcode();
if (Opcode == TargetOpcode::INLINEASM ||
Opcode == TargetOpcode::INLINEASM_BR) {
const MachineFunction &MF = *MI.getParent()->getParent();
const auto &TM = static_cast<const RISCVTargetMachine &>(MF.getTarget());
return getInlineAsmLength(MI.getOperand(0).getSymbolName(),
*TM.getMCAsmInfo());
}
if (MI.getParent() && MI.getParent()->getParent()) {
if (isCompressibleInst(MI, STI))
return 2;
}
return get(Opcode).getSize();
}
bool RISCVInstrInfo::isAsCheapAsAMove(const MachineInstr &MI) const {
const unsigned Opcode = MI.getOpcode();
switch (Opcode) {
default:
break;
case RISCV::FSGNJ_D:
case RISCV::FSGNJ_S:
case RISCV::FSGNJ_H:
// The canonical floating-point move is fsgnj rd, rs, rs.
return MI.getOperand(1).isReg() && MI.getOperand(2).isReg() &&
MI.getOperand(1).getReg() == MI.getOperand(2).getReg();
case RISCV::ADDI:
case RISCV::ORI:
case RISCV::XORI:
return (MI.getOperand(1).isReg() &&
MI.getOperand(1).getReg() == RISCV::X0) ||
(MI.getOperand(2).isImm() && MI.getOperand(2).getImm() == 0);
}
return MI.isAsCheapAsAMove();
}
std::optional<DestSourcePair>
RISCVInstrInfo::isCopyInstrImpl(const MachineInstr &MI) const {
if (MI.isMoveReg())
return DestSourcePair{MI.getOperand(0), MI.getOperand(1)};
switch (MI.getOpcode()) {
default:
break;
case RISCV::ADDI:
// Operand 1 can be a frameindex but callers expect registers
if (MI.getOperand(1).isReg() && MI.getOperand(2).isImm() &&
MI.getOperand(2).getImm() == 0)
return DestSourcePair{MI.getOperand(0), MI.getOperand(1)};
break;
case RISCV::FSGNJ_D:
case RISCV::FSGNJ_S:
case RISCV::FSGNJ_H:
// The canonical floating-point move is fsgnj rd, rs, rs.
if (MI.getOperand(1).isReg() && MI.getOperand(2).isReg() &&
MI.getOperand(1).getReg() == MI.getOperand(2).getReg())
return DestSourcePair{MI.getOperand(0), MI.getOperand(1)};
break;
}
return std::nullopt;
}
void RISCVInstrInfo::setSpecialOperandAttr(MachineInstr &OldMI1,
MachineInstr &OldMI2,
MachineInstr &NewMI1,
MachineInstr &NewMI2) const {
uint16_t IntersectedFlags = OldMI1.getFlags() & OldMI2.getFlags();
NewMI1.setFlags(IntersectedFlags);
NewMI2.setFlags(IntersectedFlags);
}
void RISCVInstrInfo::finalizeInsInstrs(
MachineInstr &Root, MachineCombinerPattern &P,
SmallVectorImpl<MachineInstr *> &InsInstrs) const {
int16_t FrmOpIdx =
RISCV::getNamedOperandIdx(Root.getOpcode(), RISCV::OpName::frm);
if (FrmOpIdx < 0) {
assert(all_of(InsInstrs,
[](MachineInstr *MI) {
return RISCV::getNamedOperandIdx(MI->getOpcode(),
RISCV::OpName::frm) < 0;
}) &&
"New instructions require FRM whereas the old one does not have it");
return;
}
const MachineOperand &FRM = Root.getOperand(FrmOpIdx);
MachineFunction &MF = *Root.getMF();
for (auto *NewMI : InsInstrs) {
assert(static_cast<unsigned>(RISCV::getNamedOperandIdx(
NewMI->getOpcode(), RISCV::OpName::frm)) ==
NewMI->getNumOperands() &&
"Instruction has unexpected number of operands");
MachineInstrBuilder MIB(MF, NewMI);
MIB.add(FRM);
if (FRM.getImm() == RISCVFPRndMode::DYN)
MIB.addUse(RISCV::FRM, RegState::Implicit);
}
}
static bool isFADD(unsigned Opc) {
switch (Opc) {
default:
return false;
case RISCV::FADD_H:
case RISCV::FADD_S:
case RISCV::FADD_D:
return true;
}
}
static bool isFSUB(unsigned Opc) {
switch (Opc) {
default:
return false;
case RISCV::FSUB_H:
case RISCV::FSUB_S:
case RISCV::FSUB_D:
return true;
}
}
static bool isFMUL(unsigned Opc) {
switch (Opc) {
default:
return false;
case RISCV::FMUL_H:
case RISCV::FMUL_S:
case RISCV::FMUL_D:
return true;
}
}
bool RISCVInstrInfo::hasReassociableSibling(const MachineInstr &Inst,
bool &Commuted) const {
if (!TargetInstrInfo::hasReassociableSibling(Inst, Commuted))
return false;
const MachineRegisterInfo &MRI = Inst.getMF()->getRegInfo();
unsigned OperandIdx = Commuted ? 2 : 1;
const MachineInstr &Sibling =
*MRI.getVRegDef(Inst.getOperand(OperandIdx).getReg());
int16_t InstFrmOpIdx =
RISCV::getNamedOperandIdx(Inst.getOpcode(), RISCV::OpName::frm);
int16_t SiblingFrmOpIdx =
RISCV::getNamedOperandIdx(Sibling.getOpcode(), RISCV::OpName::frm);
return (InstFrmOpIdx < 0 && SiblingFrmOpIdx < 0) ||
RISCV::hasEqualFRM(Inst, Sibling);
}
bool RISCVInstrInfo::isAssociativeAndCommutative(const MachineInstr &Inst,
bool Invert) const {
unsigned Opc = Inst.getOpcode();
if (Invert) {
auto InverseOpcode = getInverseOpcode(Opc);
if (!InverseOpcode)
return false;
Opc = *InverseOpcode;
}
if (isFADD(Opc) || isFMUL(Opc))
return Inst.getFlag(MachineInstr::MIFlag::FmReassoc) &&
Inst.getFlag(MachineInstr::MIFlag::FmNsz);
switch (Opc) {
default:
return false;
case RISCV::ADD:
case RISCV::ADDW:
case RISCV::AND:
case RISCV::OR:
case RISCV::XOR:
// From RISC-V ISA spec, if both the high and low bits of the same product
// are required, then the recommended code sequence is:
//
// MULH[[S]U] rdh, rs1, rs2
// MUL rdl, rs1, rs2
// (source register specifiers must be in same order and rdh cannot be the
// same as rs1 or rs2)
//
// Microarchitectures can then fuse these into a single multiply operation
// instead of performing two separate multiplies.
// MachineCombiner may reassociate MUL operands and lose the fusion
// opportunity.
case RISCV::MUL:
case RISCV::MULW:
case RISCV::MIN:
case RISCV::MINU:
case RISCV::MAX:
case RISCV::MAXU:
case RISCV::FMIN_H:
case RISCV::FMIN_S:
case RISCV::FMIN_D:
case RISCV::FMAX_H:
case RISCV::FMAX_S:
case RISCV::FMAX_D:
return true;
}
return false;
}
std::optional<unsigned>
RISCVInstrInfo::getInverseOpcode(unsigned Opcode) const {
switch (Opcode) {
default:
return std::nullopt;
case RISCV::FADD_H:
return RISCV::FSUB_H;
case RISCV::FADD_S:
return RISCV::FSUB_S;
case RISCV::FADD_D:
return RISCV::FSUB_D;
case RISCV::FSUB_H:
return RISCV::FADD_H;
case RISCV::FSUB_S:
return RISCV::FADD_S;
case RISCV::FSUB_D:
return RISCV::FADD_D;
case RISCV::ADD:
return RISCV::SUB;
case RISCV::SUB:
return RISCV::ADD;
case RISCV::ADDW:
return RISCV::SUBW;
case RISCV::SUBW:
return RISCV::ADDW;
}
}
static bool canCombineFPFusedMultiply(const MachineInstr &Root,
const MachineOperand &MO,
bool DoRegPressureReduce) {
if (!MO.isReg() || !MO.getReg().isVirtual())
return false;
const MachineRegisterInfo &MRI = Root.getMF()->getRegInfo();
MachineInstr *MI = MRI.getVRegDef(MO.getReg());
if (!MI || !isFMUL(MI->getOpcode()))
return false;
if (!Root.getFlag(MachineInstr::MIFlag::FmContract) ||
!MI->getFlag(MachineInstr::MIFlag::FmContract))
return false;
// Try combining even if fmul has more than one use as it eliminates
// dependency between fadd(fsub) and fmul. However, it can extend liveranges
// for fmul operands, so reject the transformation in register pressure
// reduction mode.
if (DoRegPressureReduce && !MRI.hasOneNonDBGUse(MI->getOperand(0).getReg()))
return false;
// Do not combine instructions from different basic blocks.
if (Root.getParent() != MI->getParent())
return false;
return RISCV::hasEqualFRM(Root, *MI);
}
static bool
getFPFusedMultiplyPatterns(MachineInstr &Root,
SmallVectorImpl<MachineCombinerPattern> &Patterns,
bool DoRegPressureReduce) {
unsigned Opc = Root.getOpcode();
bool IsFAdd = isFADD(Opc);
if (!IsFAdd && !isFSUB(Opc))
return false;
bool Added = false;
if (canCombineFPFusedMultiply(Root, Root.getOperand(1),
DoRegPressureReduce)) {
Patterns.push_back(IsFAdd ? MachineCombinerPattern::FMADD_AX
: MachineCombinerPattern::FMSUB);
Added = true;
}
if (canCombineFPFusedMultiply(Root, Root.getOperand(2),
DoRegPressureReduce)) {
Patterns.push_back(IsFAdd ? MachineCombinerPattern::FMADD_XA
: MachineCombinerPattern::FNMSUB);
Added = true;
}
return Added;
}
static bool getFPPatterns(MachineInstr &Root,
SmallVectorImpl<MachineCombinerPattern> &Patterns,
bool DoRegPressureReduce) {
return getFPFusedMultiplyPatterns(Root, Patterns, DoRegPressureReduce);
}
bool RISCVInstrInfo::getMachineCombinerPatterns(
MachineInstr &Root, SmallVectorImpl<MachineCombinerPattern> &Patterns,
bool DoRegPressureReduce) const {
if (getFPPatterns(Root, Patterns, DoRegPressureReduce))
return true;
return TargetInstrInfo::getMachineCombinerPatterns(Root, Patterns,
DoRegPressureReduce);
}
static unsigned getFPFusedMultiplyOpcode(unsigned RootOpc,
MachineCombinerPattern Pattern) {
switch (RootOpc) {
default:
llvm_unreachable("Unexpected opcode");
case RISCV::FADD_H:
return RISCV::FMADD_H;
case RISCV::FADD_S:
return RISCV::FMADD_S;
case RISCV::FADD_D:
return RISCV::FMADD_D;
case RISCV::FSUB_H:
return Pattern == MachineCombinerPattern::FMSUB ? RISCV::FMSUB_H
: RISCV::FNMSUB_H;
case RISCV::FSUB_S:
return Pattern == MachineCombinerPattern::FMSUB ? RISCV::FMSUB_S
: RISCV::FNMSUB_S;
case RISCV::FSUB_D:
return Pattern == MachineCombinerPattern::FMSUB ? RISCV::FMSUB_D
: RISCV::FNMSUB_D;
}
}
static unsigned getAddendOperandIdx(MachineCombinerPattern Pattern) {
switch (Pattern) {
default:
llvm_unreachable("Unexpected pattern");
case MachineCombinerPattern::FMADD_AX:
case MachineCombinerPattern::FMSUB:
return 2;
case MachineCombinerPattern::FMADD_XA:
case MachineCombinerPattern::FNMSUB:
return 1;
}
}
static void combineFPFusedMultiply(MachineInstr &Root, MachineInstr &Prev,
MachineCombinerPattern Pattern,
SmallVectorImpl<MachineInstr *> &InsInstrs,
SmallVectorImpl<MachineInstr *> &DelInstrs) {
MachineFunction *MF = Root.getMF();
MachineRegisterInfo &MRI = MF->getRegInfo();
const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
MachineOperand &Mul1 = Prev.getOperand(1);
MachineOperand &Mul2 = Prev.getOperand(2);
MachineOperand &Dst = Root.getOperand(0);
MachineOperand &Addend = Root.getOperand(getAddendOperandIdx(Pattern));
Register DstReg = Dst.getReg();
unsigned FusedOpc = getFPFusedMultiplyOpcode(Root.getOpcode(), Pattern);
auto IntersectedFlags = Root.getFlags() & Prev.getFlags();
DebugLoc MergedLoc =
DILocation::getMergedLocation(Root.getDebugLoc(), Prev.getDebugLoc());
MachineInstrBuilder MIB =
BuildMI(*MF, MergedLoc, TII->get(FusedOpc), DstReg)
.addReg(Mul1.getReg(), getKillRegState(Mul1.isKill()))
.addReg(Mul2.getReg(), getKillRegState(Mul2.isKill()))
.addReg(Addend.getReg(), getKillRegState(Addend.isKill()))
.setMIFlags(IntersectedFlags);
// Mul operands are not killed anymore.
Mul1.setIsKill(false);
Mul2.setIsKill(false);
InsInstrs.push_back(MIB);
if (MRI.hasOneNonDBGUse(Prev.getOperand(0).getReg()))
DelInstrs.push_back(&Prev);
DelInstrs.push_back(&Root);
}
void RISCVInstrInfo::genAlternativeCodeSequence(
MachineInstr &Root, MachineCombinerPattern Pattern,
SmallVectorImpl<MachineInstr *> &InsInstrs,
SmallVectorImpl<MachineInstr *> &DelInstrs,
DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const {
MachineRegisterInfo &MRI = Root.getMF()->getRegInfo();
switch (Pattern) {
default:
TargetInstrInfo::genAlternativeCodeSequence(Root, Pattern, InsInstrs,
DelInstrs, InstrIdxForVirtReg);
return;
case MachineCombinerPattern::FMADD_AX:
case MachineCombinerPattern::FMSUB: {
MachineInstr &Prev = *MRI.getVRegDef(Root.getOperand(1).getReg());
combineFPFusedMultiply(Root, Prev, Pattern, InsInstrs, DelInstrs);
return;
}
case MachineCombinerPattern::FMADD_XA:
case MachineCombinerPattern::FNMSUB: {
MachineInstr &Prev = *MRI.getVRegDef(Root.getOperand(2).getReg());
combineFPFusedMultiply(Root, Prev, Pattern, InsInstrs, DelInstrs);
return;
}
}
}
bool RISCVInstrInfo::verifyInstruction(const MachineInstr &MI,
StringRef &ErrInfo) const {
MCInstrDesc const &Desc = MI.getDesc();
for (auto &OI : enumerate(Desc.operands())) {
unsigned OpType = OI.value().OperandType;
if (OpType >= RISCVOp::OPERAND_FIRST_RISCV_IMM &&
OpType <= RISCVOp::OPERAND_LAST_RISCV_IMM) {
const MachineOperand &MO = MI.getOperand(OI.index());
if (MO.isImm()) {
int64_t Imm = MO.getImm();
bool Ok;
switch (OpType) {
default:
llvm_unreachable("Unexpected operand type");
// clang-format off
#define CASE_OPERAND_UIMM(NUM) \
case RISCVOp::OPERAND_UIMM##NUM: \
Ok = isUInt<NUM>(Imm); \
break;
CASE_OPERAND_UIMM(2)
CASE_OPERAND_UIMM(3)
CASE_OPERAND_UIMM(4)
CASE_OPERAND_UIMM(5)
CASE_OPERAND_UIMM(7)
case RISCVOp::OPERAND_UIMM7_LSB00:
Ok = isShiftedUInt<5, 2>(Imm);
break;
case RISCVOp::OPERAND_UIMM8_LSB00:
Ok = isShiftedUInt<6, 2>(Imm);
break;
case RISCVOp::OPERAND_UIMM8_LSB000:
Ok = isShiftedUInt<5, 3>(Imm);
break;
CASE_OPERAND_UIMM(12)
CASE_OPERAND_UIMM(20)
// clang-format on
case RISCVOp::OPERAND_SIMM10_LSB0000_NONZERO:
Ok = isShiftedInt<6, 4>(Imm) && (Imm != 0);
break;
case RISCVOp::OPERAND_ZERO:
Ok = Imm == 0;
break;
case RISCVOp::OPERAND_SIMM5:
Ok = isInt<5>(Imm);
break;
case RISCVOp::OPERAND_SIMM5_PLUS1:
Ok = (isInt<5>(Imm) && Imm != -16) || Imm == 16;
break;
case RISCVOp::OPERAND_SIMM6:
Ok = isInt<6>(Imm);
break;
case RISCVOp::OPERAND_SIMM6_NONZERO:
Ok = Imm != 0 && isInt<6>(Imm);
break;
case RISCVOp::OPERAND_VTYPEI10:
Ok = isUInt<10>(Imm);
break;
case RISCVOp::OPERAND_VTYPEI11:
Ok = isUInt<11>(Imm);
break;
case RISCVOp::OPERAND_SIMM12:
Ok = isInt<12>(Imm);
break;
case RISCVOp::OPERAND_SIMM12_LSB00000:
Ok = isShiftedInt<7, 5>(Imm);
break;
case RISCVOp::OPERAND_UIMMLOG2XLEN:
Ok = STI.is64Bit() ? isUInt<6>(Imm) : isUInt<5>(Imm);
break;
case RISCVOp::OPERAND_UIMMLOG2XLEN_NONZERO:
Ok = STI.is64Bit() ? isUInt<6>(Imm) : isUInt<5>(Imm);
Ok = Ok && Imm != 0;
break;
case RISCVOp::OPERAND_UIMM_SHFL:
Ok = STI.is64Bit() ? isUInt<5>(Imm) : isUInt<4>(Imm);
break;
case RISCVOp::OPERAND_RVKRNUM:
Ok = Imm >= 0 && Imm <= 10;
break;
}
if (!Ok) {
ErrInfo = "Invalid immediate";
return false;
}
}
}
}
const uint64_t TSFlags = Desc.TSFlags;
if (RISCVII::hasMergeOp(TSFlags)) {
unsigned OpIdx = RISCVII::getMergeOpNum(Desc);
if (MI.findTiedOperandIdx(0) != OpIdx) {
ErrInfo = "Merge op improperly tied";
return false;
}
}
if (RISCVII::hasVLOp(TSFlags)) {
const MachineOperand &Op = MI.getOperand(RISCVII::getVLOpNum(Desc));
if (!Op.isImm() && !Op.isReg()) {
ErrInfo = "Invalid operand type for VL operand";
return false;
}
if (Op.isReg() && Op.getReg() != RISCV::NoRegister) {
const MachineRegisterInfo &MRI = MI.getParent()->getParent()->getRegInfo();
auto *RC = MRI.getRegClass(Op.getReg());
if (!RISCV::GPRRegClass.hasSubClassEq(RC)) {
ErrInfo = "Invalid register class for VL operand";
return false;
}
}
if (!RISCVII::hasSEWOp(TSFlags)) {
ErrInfo = "VL operand w/o SEW operand?";
return false;
}
}
if (RISCVII::hasSEWOp(TSFlags)) {
unsigned OpIdx = RISCVII::getSEWOpNum(Desc);
uint64_t Log2SEW = MI.getOperand(OpIdx).getImm();
if (Log2SEW > 31) {
ErrInfo = "Unexpected SEW value";
return false;
}
unsigned SEW = Log2SEW ? 1 << Log2SEW : 8;
if (!RISCVVType::isValidSEW(SEW)) {
ErrInfo = "Unexpected SEW value";
return false;
}
}
if (RISCVII::hasVecPolicyOp(TSFlags)) {
unsigned OpIdx = RISCVII::getVecPolicyOpNum(Desc);
uint64_t Policy = MI.getOperand(OpIdx).getImm();
if (Policy > (RISCVII::TAIL_AGNOSTIC | RISCVII::MASK_AGNOSTIC)) {
ErrInfo = "Invalid Policy Value";
return false;
}
if (!RISCVII::hasVLOp(TSFlags)) {
ErrInfo = "policy operand w/o VL operand?";
return false;
}
// VecPolicy operands can only exist on instructions with passthru/merge
// arguments. Note that not all arguments with passthru have vec policy
// operands- some instructions have implicit policies.
unsigned UseOpIdx;
if (!MI.isRegTiedToUseOperand(0, &UseOpIdx)) {
ErrInfo = "policy operand w/o tied operand?";
return false;
}
}
return true;
}
// Return true if get the base operand, byte offset of an instruction and the
// memory width. Width is the size of memory that is being loaded/stored.
bool RISCVInstrInfo::getMemOperandWithOffsetWidth(
const MachineInstr &LdSt, const MachineOperand *&BaseReg, int64_t &Offset,
unsigned &Width, const TargetRegisterInfo *TRI) const {
if (!LdSt.mayLoadOrStore())
return false;
// Here we assume the standard RISC-V ISA, which uses a base+offset
// addressing mode. You'll need to relax these conditions to support custom
// load/stores instructions.
if (LdSt.getNumExplicitOperands() != 3)
return false;
if (!LdSt.getOperand(1).isReg() || !LdSt.getOperand(2).isImm())
return false;
if (!LdSt.hasOneMemOperand())
return false;
Width = (*LdSt.memoperands_begin())->getSize();
BaseReg = &LdSt.getOperand(1);
Offset = LdSt.getOperand(2).getImm();
return true;
}
bool RISCVInstrInfo::areMemAccessesTriviallyDisjoint(
const MachineInstr &MIa, const MachineInstr &MIb) const {
assert(MIa.mayLoadOrStore() && "MIa must be a load or store.");
assert(MIb.mayLoadOrStore() && "MIb must be a load or store.");
if (MIa.hasUnmodeledSideEffects() || MIb.hasUnmodeledSideEffects() ||
MIa.hasOrderedMemoryRef() || MIb.hasOrderedMemoryRef())
return false;
// Retrieve the base register, offset from the base register and width. Width
// is the size of memory that is being loaded/stored (e.g. 1, 2, 4). If
// base registers are identical, and the offset of a lower memory access +
// the width doesn't overlap the offset of a higher memory access,
// then the memory accesses are different.
const TargetRegisterInfo *TRI = STI.getRegisterInfo();
const MachineOperand *BaseOpA = nullptr, *BaseOpB = nullptr;
int64_t OffsetA = 0, OffsetB = 0;
unsigned int WidthA = 0, WidthB = 0;
if (getMemOperandWithOffsetWidth(MIa, BaseOpA, OffsetA, WidthA, TRI) &&
getMemOperandWithOffsetWidth(MIb, BaseOpB, OffsetB, WidthB, TRI)) {
if (BaseOpA->isIdenticalTo(*BaseOpB)) {
int LowOffset = std::min(OffsetA, OffsetB);
int HighOffset = std::max(OffsetA, OffsetB);
int LowWidth = (LowOffset == OffsetA) ? WidthA : WidthB;
if (LowOffset + LowWidth <= HighOffset)
return true;
}
}
return false;
}
std::pair<unsigned, unsigned>
RISCVInstrInfo::decomposeMachineOperandsTargetFlags(unsigned TF) const {
const unsigned Mask = RISCVII::MO_DIRECT_FLAG_MASK;
return std::make_pair(TF & Mask, TF & ~Mask);
}
ArrayRef<std::pair<unsigned, const char *>>
RISCVInstrInfo::getSerializableDirectMachineOperandTargetFlags() const {
using namespace RISCVII;
static const std::pair<unsigned, const char *> TargetFlags[] = {
{MO_CALL, "riscv-call"},
{MO_PLT, "riscv-plt"},
{MO_LO, "riscv-lo"},
{MO_HI, "riscv-hi"},
{MO_PCREL_LO, "riscv-pcrel-lo"},
{MO_PCREL_HI, "riscv-pcrel-hi"},
{MO_GOT_HI, "riscv-got-hi"},
{MO_TPREL_LO, "riscv-tprel-lo"},
{MO_TPREL_HI, "riscv-tprel-hi"},
{MO_TPREL_ADD, "riscv-tprel-add"},
{MO_TLS_GOT_HI, "riscv-tls-got-hi"},
{MO_TLS_GD_HI, "riscv-tls-gd-hi"}};
return ArrayRef(TargetFlags);
}
bool RISCVInstrInfo::isFunctionSafeToOutlineFrom(
MachineFunction &MF, bool OutlineFromLinkOnceODRs) const {
const Function &F = MF.getFunction();
// Can F be deduplicated by the linker? If it can, don't outline from it.
if (!OutlineFromLinkOnceODRs && F.hasLinkOnceODRLinkage())
return false;
// Don't outline from functions with section markings; the program could
// expect that all the code is in the named section.
if (F.hasSection())
return false;
// It's safe to outline from MF.
return true;
}
bool RISCVInstrInfo::isMBBSafeToOutlineFrom(MachineBasicBlock &MBB,
unsigned &Flags) const {
// More accurate safety checking is done in getOutliningCandidateInfo.
return TargetInstrInfo::isMBBSafeToOutlineFrom(MBB, Flags);
}
// Enum values indicating how an outlined call should be constructed.
enum MachineOutlinerConstructionID {
MachineOutlinerDefault
};
bool RISCVInstrInfo::shouldOutlineFromFunctionByDefault(
MachineFunction &MF) const {
return MF.getFunction().hasMinSize();
}
outliner::OutlinedFunction RISCVInstrInfo::getOutliningCandidateInfo(
std::vector<outliner::Candidate> &RepeatedSequenceLocs) const {
// First we need to filter out candidates where the X5 register (IE t0) can't
// be used to setup the function call.
auto CannotInsertCall = [](outliner::Candidate &C) {
const TargetRegisterInfo *TRI = C.getMF()->getSubtarget().getRegisterInfo();
return !C.isAvailableAcrossAndOutOfSeq(RISCV::X5, *TRI);
};
llvm::erase_if(RepeatedSequenceLocs, CannotInsertCall);
// If the sequence doesn't have enough candidates left, then we're done.
if (RepeatedSequenceLocs.size() < 2)
return outliner::OutlinedFunction();
unsigned SequenceSize = 0;
auto I = RepeatedSequenceLocs[0].front();
auto E = std::next(RepeatedSequenceLocs[0].back());
for (; I != E; ++I)
SequenceSize += getInstSizeInBytes(*I);
// call t0, function = 8 bytes.
unsigned CallOverhead = 8;
for (auto &C : RepeatedSequenceLocs)
C.setCallInfo(MachineOutlinerDefault, CallOverhead);
// jr t0 = 4 bytes, 2 bytes if compressed instructions are enabled.
unsigned FrameOverhead = 4;
if (RepeatedSequenceLocs[0]
.getMF()
->getSubtarget<RISCVSubtarget>()
.hasStdExtCOrZca())
FrameOverhead = 2;
return outliner::OutlinedFunction(RepeatedSequenceLocs, SequenceSize,
FrameOverhead, MachineOutlinerDefault);
}
outliner::InstrType
RISCVInstrInfo::getOutliningType(MachineBasicBlock::iterator &MBBI,
unsigned Flags) const {
MachineInstr &MI = *MBBI;
MachineBasicBlock *MBB = MI.getParent();
const TargetRegisterInfo *TRI =
MBB->getParent()->getSubtarget().getRegisterInfo();
const auto &F = MI.getMF()->getFunction();
// Positions generally can't safely be outlined.
if (MI.isPosition()) {
// We can manually strip out CFI instructions later.
if (MI.isCFIInstruction())
// If current function has exception handling code, we can't outline &
// strip these CFI instructions since it may break .eh_frame section
// needed in unwinding.
return F.needsUnwindTableEntry() ? outliner::InstrType::Illegal
: outliner::InstrType::Invisible;
return outliner::InstrType::Illegal;
}
// Don't trust the user to write safe inline assembly.
if (MI.isInlineAsm())
return outliner::InstrType::Illegal;
// We can't outline branches to other basic blocks.
if (MI.isTerminator() && !MBB->succ_empty())
return outliner::InstrType::Illegal;
// We need support for tail calls to outlined functions before return
// statements can be allowed.
if (MI.isReturn())
return outliner::InstrType::Illegal;
// Don't allow modifying the X5 register which we use for return addresses for
// these outlined functions.
if (MI.modifiesRegister(RISCV::X5, TRI) ||
MI.getDesc().hasImplicitDefOfPhysReg(RISCV::X5))
return outliner::InstrType::Illegal;
// Make sure the operands don't reference something unsafe.
for (const auto &MO : MI.operands()) {
if (MO.isMBB() || MO.isBlockAddress() || MO.isCPI() || MO.isJTI())
return outliner::InstrType::Illegal;
// pcrel-hi and pcrel-lo can't put in separate sections, filter that out
// if any possible.
if (MO.getTargetFlags() == RISCVII::MO_PCREL_LO &&
(MI.getMF()->getTarget().getFunctionSections() || F.hasComdat() ||
F.hasSection()))
return outliner::InstrType::Illegal;
}
// Don't allow instructions which won't be materialized to impact outlining
// analysis.
if (MI.isMetaInstruction())
return outliner::InstrType::Invisible;
return outliner::InstrType::Legal;
}
void RISCVInstrInfo::buildOutlinedFrame(
MachineBasicBlock &MBB, MachineFunction &MF,
const outliner::OutlinedFunction &OF) const {
// Strip out any CFI instructions
bool Changed = true;
while (Changed) {
Changed = false;
auto I = MBB.begin();
auto E = MBB.end();
for (; I != E; ++I) {
if (I->isCFIInstruction()) {
I->removeFromParent();
Changed = true;
break;
}
}
}
MBB.addLiveIn(RISCV::X5);
// Add in a return instruction to the end of the outlined frame.
MBB.insert(MBB.end(), BuildMI(MF, DebugLoc(), get(RISCV::JALR))
.addReg(RISCV::X0, RegState::Define)
.addReg(RISCV::X5)
.addImm(0));
}
MachineBasicBlock::iterator RISCVInstrInfo::insertOutlinedCall(
Module &M, MachineBasicBlock &MBB, MachineBasicBlock::iterator &It,
MachineFunction &MF, outliner::Candidate &C) const {
// Add in a call instruction to the outlined function at the given location.
It = MBB.insert(It,
BuildMI(MF, DebugLoc(), get(RISCV::PseudoCALLReg), RISCV::X5)
.addGlobalAddress(M.getNamedValue(MF.getName()), 0,
RISCVII::MO_CALL));
return It;
}
// MIR printer helper function to annotate Operands with a comment.
std::string RISCVInstrInfo::createMIROperandComment(
const MachineInstr &MI, const MachineOperand &Op, unsigned OpIdx,
const TargetRegisterInfo *TRI) const {
// Print a generic comment for this operand if there is one.
std::string GenericComment =
TargetInstrInfo::createMIROperandComment(MI, Op, OpIdx, TRI);
if (!GenericComment.empty())
return GenericComment;
// If not, we must have an immediate operand.
if (!Op.isImm())
return std::string();
std::string Comment;
raw_string_ostream OS(Comment);
uint64_t TSFlags = MI.getDesc().TSFlags;
// Print the full VType operand of vsetvli/vsetivli instructions, and the SEW
// operand of vector codegen pseudos.
if ((MI.getOpcode() == RISCV::VSETVLI || MI.getOpcode() == RISCV::VSETIVLI ||
MI.getOpcode() == RISCV::PseudoVSETVLI ||
MI.getOpcode() == RISCV::PseudoVSETIVLI ||
MI.getOpcode() == RISCV::PseudoVSETVLIX0) &&
OpIdx == 2) {
unsigned Imm = MI.getOperand(OpIdx).getImm();
RISCVVType::printVType(Imm, OS);
} else if (RISCVII::hasSEWOp(TSFlags) &&
OpIdx == RISCVII::getSEWOpNum(MI.getDesc())) {
unsigned Log2SEW = MI.getOperand(OpIdx).getImm();
unsigned SEW = Log2SEW ? 1 << Log2SEW : 8;
assert(RISCVVType::isValidSEW(SEW) && "Unexpected SEW");
OS << "e" << SEW;
} else if (RISCVII::hasVecPolicyOp(TSFlags) &&
OpIdx == RISCVII::getVecPolicyOpNum(MI.getDesc())) {
unsigned Policy = MI.getOperand(OpIdx).getImm();
assert(Policy <= (RISCVII::TAIL_AGNOSTIC | RISCVII::MASK_AGNOSTIC) &&
"Invalid Policy Value");
OS << (Policy & RISCVII::TAIL_AGNOSTIC ? "ta" : "tu") << ", "
<< (Policy & RISCVII::MASK_AGNOSTIC ? "ma" : "mu");
}
OS.flush();
return Comment;
}
// clang-format off
#define CASE_VFMA_OPCODE_COMMON(OP, TYPE, LMUL) \
RISCV::PseudoV##OP##_##TYPE##_##LMUL
#define CASE_VFMA_OPCODE_LMULS_M1(OP, TYPE) \
CASE_VFMA_OPCODE_COMMON(OP, TYPE, M1): \
case CASE_VFMA_OPCODE_COMMON(OP, TYPE, M2): \
case CASE_VFMA_OPCODE_COMMON(OP, TYPE, M4): \
case CASE_VFMA_OPCODE_COMMON(OP, TYPE, M8)
#define CASE_VFMA_OPCODE_LMULS_MF2(OP, TYPE) \
CASE_VFMA_OPCODE_COMMON(OP, TYPE, MF2): \
case CASE_VFMA_OPCODE_LMULS_M1(OP, TYPE)
#define CASE_VFMA_OPCODE_LMULS_MF4(OP, TYPE) \
CASE_VFMA_OPCODE_COMMON(OP, TYPE, MF4): \
case CASE_VFMA_OPCODE_LMULS_MF2(OP, TYPE)
#define CASE_VFMA_OPCODE_LMULS(OP, TYPE) \
CASE_VFMA_OPCODE_COMMON(OP, TYPE, MF8): \
case CASE_VFMA_OPCODE_LMULS_MF4(OP, TYPE)
#define CASE_VFMA_SPLATS(OP) \
CASE_VFMA_OPCODE_LMULS_MF4(OP, VF16): \
case CASE_VFMA_OPCODE_LMULS_MF2(OP, VF32): \
case CASE_VFMA_OPCODE_LMULS_M1(OP, VF64)
// clang-format on
bool RISCVInstrInfo::findCommutedOpIndices(const MachineInstr &MI,
unsigned &SrcOpIdx1,
unsigned &SrcOpIdx2) const {
const MCInstrDesc &Desc = MI.getDesc();
if (!Desc.isCommutable())
return false;
switch (MI.getOpcode()) {
case RISCV::PseudoCCMOVGPR:
// Operands 4 and 5 are commutable.
return fixCommutedOpIndices(SrcOpIdx1, SrcOpIdx2, 4, 5);
case CASE_VFMA_SPLATS(FMADD):
case CASE_VFMA_SPLATS(FMSUB):
case CASE_VFMA_SPLATS(FMACC):
case CASE_VFMA_SPLATS(FMSAC):
case CASE_VFMA_SPLATS(FNMADD):
case CASE_VFMA_SPLATS(FNMSUB):
case CASE_VFMA_SPLATS(FNMACC):
case CASE_VFMA_SPLATS(FNMSAC):
case CASE_VFMA_OPCODE_LMULS_MF4(FMACC, VV):
case CASE_VFMA_OPCODE_LMULS_MF4(FMSAC, VV):
case CASE_VFMA_OPCODE_LMULS_MF4(FNMACC, VV):
case CASE_VFMA_OPCODE_LMULS_MF4(FNMSAC, VV):
case CASE_VFMA_OPCODE_LMULS(MADD, VX):
case CASE_VFMA_OPCODE_LMULS(NMSUB, VX):
case CASE_VFMA_OPCODE_LMULS(MACC, VX):
case CASE_VFMA_OPCODE_LMULS(NMSAC, VX):
case CASE_VFMA_OPCODE_LMULS(MACC, VV):
case CASE_VFMA_OPCODE_LMULS(NMSAC, VV): {
// If the tail policy is undisturbed we can't commute.
assert(RISCVII::hasVecPolicyOp(MI.getDesc().TSFlags));
if ((MI.getOperand(MI.getNumExplicitOperands() - 1).getImm() & 1) == 0)
return false;
// For these instructions we can only swap operand 1 and operand 3 by
// changing the opcode.
unsigned CommutableOpIdx1 = 1;
unsigned CommutableOpIdx2 = 3;
if (!fixCommutedOpIndices(SrcOpIdx1, SrcOpIdx2, CommutableOpIdx1,
CommutableOpIdx2))
return false;
return true;
}
case CASE_VFMA_OPCODE_LMULS_MF4(FMADD, VV):
case CASE_VFMA_OPCODE_LMULS_MF4(FMSUB, VV):
case CASE_VFMA_OPCODE_LMULS_MF4(FNMADD, VV):
case CASE_VFMA_OPCODE_LMULS_MF4(FNMSUB, VV):
case CASE_VFMA_OPCODE_LMULS(MADD, VV):
case CASE_VFMA_OPCODE_LMULS(NMSUB, VV): {
// If the tail policy is undisturbed we can't commute.
assert(RISCVII::hasVecPolicyOp(MI.getDesc().TSFlags));
if ((MI.getOperand(MI.getNumExplicitOperands() - 1).getImm() & 1) == 0)
return false;
// For these instructions we have more freedom. We can commute with the
// other multiplicand or with the addend/subtrahend/minuend.
// Any fixed operand must be from source 1, 2 or 3.
if (SrcOpIdx1 != CommuteAnyOperandIndex && SrcOpIdx1 > 3)
return false;
if (SrcOpIdx2 != CommuteAnyOperandIndex && SrcOpIdx2 > 3)
return false;
// It both ops are fixed one must be the tied source.
if (SrcOpIdx1 != CommuteAnyOperandIndex &&
SrcOpIdx2 != CommuteAnyOperandIndex && SrcOpIdx1 != 1 && SrcOpIdx2 != 1)
return false;
// Look for two different register operands assumed to be commutable
// regardless of the FMA opcode. The FMA opcode is adjusted later if
// needed.
if (SrcOpIdx1 == CommuteAnyOperandIndex ||
SrcOpIdx2 == CommuteAnyOperandIndex) {
// At least one of operands to be commuted is not specified and
// this method is free to choose appropriate commutable operands.
unsigned CommutableOpIdx1 = SrcOpIdx1;
if (SrcOpIdx1 == SrcOpIdx2) {
// Both of operands are not fixed. Set one of commutable
// operands to the tied source.
CommutableOpIdx1 = 1;
} else if (SrcOpIdx1 == CommuteAnyOperandIndex) {
// Only one of the operands is not fixed.
CommutableOpIdx1 = SrcOpIdx2;
}
// CommutableOpIdx1 is well defined now. Let's choose another commutable
// operand and assign its index to CommutableOpIdx2.
unsigned CommutableOpIdx2;
if (CommutableOpIdx1 != 1) {
// If we haven't already used the tied source, we must use it now.
CommutableOpIdx2 = 1;
} else {
Register Op1Reg = MI.getOperand(CommutableOpIdx1).getReg();
// The commuted operands should have different registers.
// Otherwise, the commute transformation does not change anything and
// is useless. We use this as a hint to make our decision.
if (Op1Reg != MI.getOperand(2).getReg())
CommutableOpIdx2 = 2;
else
CommutableOpIdx2 = 3;
}
// Assign the found pair of commutable indices to SrcOpIdx1 and
// SrcOpIdx2 to return those values.
if (!fixCommutedOpIndices(SrcOpIdx1, SrcOpIdx2, CommutableOpIdx1,
CommutableOpIdx2))
return false;
}
return true;
}
}
return TargetInstrInfo::findCommutedOpIndices(MI, SrcOpIdx1, SrcOpIdx2);
}
#define CASE_VFMA_CHANGE_OPCODE_COMMON(OLDOP, NEWOP, TYPE, LMUL) \
case RISCV::PseudoV##OLDOP##_##TYPE##_##LMUL: \
Opc = RISCV::PseudoV##NEWOP##_##TYPE##_##LMUL; \
break;
#define CASE_VFMA_CHANGE_OPCODE_LMULS_M1(OLDOP, NEWOP, TYPE) \
CASE_VFMA_CHANGE_OPCODE_COMMON(OLDOP, NEWOP, TYPE, M1) \
CASE_VFMA_CHANGE_OPCODE_COMMON(OLDOP, NEWOP, TYPE, M2) \
CASE_VFMA_CHANGE_OPCODE_COMMON(OLDOP, NEWOP, TYPE, M4) \
CASE_VFMA_CHANGE_OPCODE_COMMON(OLDOP, NEWOP, TYPE, M8)
#define CASE_VFMA_CHANGE_OPCODE_LMULS_MF2(OLDOP, NEWOP, TYPE) \
CASE_VFMA_CHANGE_OPCODE_COMMON(OLDOP, NEWOP, TYPE, MF2) \
CASE_VFMA_CHANGE_OPCODE_LMULS_M1(OLDOP, NEWOP, TYPE)
#define CASE_VFMA_CHANGE_OPCODE_LMULS_MF4(OLDOP, NEWOP, TYPE) \
CASE_VFMA_CHANGE_OPCODE_COMMON(OLDOP, NEWOP, TYPE, MF4) \
CASE_VFMA_CHANGE_OPCODE_LMULS_MF2(OLDOP, NEWOP, TYPE)
#define CASE_VFMA_CHANGE_OPCODE_LMULS(OLDOP, NEWOP, TYPE) \
CASE_VFMA_CHANGE_OPCODE_COMMON(OLDOP, NEWOP, TYPE, MF8) \
CASE_VFMA_CHANGE_OPCODE_LMULS_MF4(OLDOP, NEWOP, TYPE)
#define CASE_VFMA_CHANGE_OPCODE_SPLATS(OLDOP, NEWOP) \
CASE_VFMA_CHANGE_OPCODE_LMULS_MF4(OLDOP, NEWOP, VF16) \
CASE_VFMA_CHANGE_OPCODE_LMULS_MF2(OLDOP, NEWOP, VF32) \
CASE_VFMA_CHANGE_OPCODE_LMULS_M1(OLDOP, NEWOP, VF64)
MachineInstr *RISCVInstrInfo::commuteInstructionImpl(MachineInstr &MI,
bool NewMI,
unsigned OpIdx1,
unsigned OpIdx2) const {
auto cloneIfNew = [NewMI](MachineInstr &MI) -> MachineInstr & {
if (NewMI)
return *MI.getParent()->getParent()->CloneMachineInstr(&MI);
return MI;
};
switch (MI.getOpcode()) {
case RISCV::PseudoCCMOVGPR: {
// CCMOV can be commuted by inverting the condition.
auto CC = static_cast<RISCVCC::CondCode>(MI.getOperand(3).getImm());
CC = RISCVCC::getOppositeBranchCondition(CC);
auto &WorkingMI = cloneIfNew(MI);
WorkingMI.getOperand(3).setImm(CC);
return TargetInstrInfo::commuteInstructionImpl(WorkingMI, /*NewMI*/ false,
OpIdx1, OpIdx2);
}
case CASE_VFMA_SPLATS(FMACC):
case CASE_VFMA_SPLATS(FMADD):
case CASE_VFMA_SPLATS(FMSAC):
case CASE_VFMA_SPLATS(FMSUB):
case CASE_VFMA_SPLATS(FNMACC):
case CASE_VFMA_SPLATS(FNMADD):
case CASE_VFMA_SPLATS(FNMSAC):
case CASE_VFMA_SPLATS(FNMSUB):
case CASE_VFMA_OPCODE_LMULS_MF4(FMACC, VV):
case CASE_VFMA_OPCODE_LMULS_MF4(FMSAC, VV):
case CASE_VFMA_OPCODE_LMULS_MF4(FNMACC, VV):
case CASE_VFMA_OPCODE_LMULS_MF4(FNMSAC, VV):
case CASE_VFMA_OPCODE_LMULS(MADD, VX):
case CASE_VFMA_OPCODE_LMULS(NMSUB, VX):
case CASE_VFMA_OPCODE_LMULS(MACC, VX):
case CASE_VFMA_OPCODE_LMULS(NMSAC, VX):
case CASE_VFMA_OPCODE_LMULS(MACC, VV):
case CASE_VFMA_OPCODE_LMULS(NMSAC, VV): {
// It only make sense to toggle these between clobbering the
// addend/subtrahend/minuend one of the multiplicands.
assert((OpIdx1 == 1 || OpIdx2 == 1) && "Unexpected opcode index");
assert((OpIdx1 == 3 || OpIdx2 == 3) && "Unexpected opcode index");
unsigned Opc;
switch (MI.getOpcode()) {
default:
llvm_unreachable("Unexpected opcode");
CASE_VFMA_CHANGE_OPCODE_SPLATS(FMACC, FMADD)
CASE_VFMA_CHANGE_OPCODE_SPLATS(FMADD, FMACC)
CASE_VFMA_CHANGE_OPCODE_SPLATS(FMSAC, FMSUB)
CASE_VFMA_CHANGE_OPCODE_SPLATS(FMSUB, FMSAC)
CASE_VFMA_CHANGE_OPCODE_SPLATS(FNMACC, FNMADD)
CASE_VFMA_CHANGE_OPCODE_SPLATS(FNMADD, FNMACC)
CASE_VFMA_CHANGE_OPCODE_SPLATS(FNMSAC, FNMSUB)
CASE_VFMA_CHANGE_OPCODE_SPLATS(FNMSUB, FNMSAC)
CASE_VFMA_CHANGE_OPCODE_LMULS_MF4(FMACC, FMADD, VV)
CASE_VFMA_CHANGE_OPCODE_LMULS_MF4(FMSAC, FMSUB, VV)
CASE_VFMA_CHANGE_OPCODE_LMULS_MF4(FNMACC, FNMADD, VV)
CASE_VFMA_CHANGE_OPCODE_LMULS_MF4(FNMSAC, FNMSUB, VV)
CASE_VFMA_CHANGE_OPCODE_LMULS(MACC, MADD, VX)
CASE_VFMA_CHANGE_OPCODE_LMULS(MADD, MACC, VX)
CASE_VFMA_CHANGE_OPCODE_LMULS(NMSAC, NMSUB, VX)
CASE_VFMA_CHANGE_OPCODE_LMULS(NMSUB, NMSAC, VX)
CASE_VFMA_CHANGE_OPCODE_LMULS(MACC, MADD, VV)
CASE_VFMA_CHANGE_OPCODE_LMULS(NMSAC, NMSUB, VV)
}
auto &WorkingMI = cloneIfNew(MI);
WorkingMI.setDesc(get(Opc));
return TargetInstrInfo::commuteInstructionImpl(WorkingMI, /*NewMI=*/false,
OpIdx1, OpIdx2);
}
case CASE_VFMA_OPCODE_LMULS_MF4(FMADD, VV):
case CASE_VFMA_OPCODE_LMULS_MF4(FMSUB, VV):
case CASE_VFMA_OPCODE_LMULS_MF4(FNMADD, VV):
case CASE_VFMA_OPCODE_LMULS_MF4(FNMSUB, VV):
case CASE_VFMA_OPCODE_LMULS(MADD, VV):
case CASE_VFMA_OPCODE_LMULS(NMSUB, VV): {
assert((OpIdx1 == 1 || OpIdx2 == 1) && "Unexpected opcode index");
// If one of the operands, is the addend we need to change opcode.
// Otherwise we're just swapping 2 of the multiplicands.
if (OpIdx1 == 3 || OpIdx2 == 3) {
unsigned Opc;
switch (MI.getOpcode()) {
default:
llvm_unreachable("Unexpected opcode");
CASE_VFMA_CHANGE_OPCODE_LMULS_MF4(FMADD, FMACC, VV)
CASE_VFMA_CHANGE_OPCODE_LMULS_MF4(FMSUB, FMSAC, VV)
CASE_VFMA_CHANGE_OPCODE_LMULS_MF4(FNMADD, FNMACC, VV)
CASE_VFMA_CHANGE_OPCODE_LMULS_MF4(FNMSUB, FNMSAC, VV)
CASE_VFMA_CHANGE_OPCODE_LMULS(MADD, MACC, VV)
CASE_VFMA_CHANGE_OPCODE_LMULS(NMSUB, NMSAC, VV)
}
auto &WorkingMI = cloneIfNew(MI);
WorkingMI.setDesc(get(Opc));
return TargetInstrInfo::commuteInstructionImpl(WorkingMI, /*NewMI=*/false,
OpIdx1, OpIdx2);
}
// Let the default code handle it.
break;
}
}
return TargetInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
}
#undef CASE_VFMA_CHANGE_OPCODE_SPLATS
#undef CASE_VFMA_CHANGE_OPCODE_LMULS
#undef CASE_VFMA_CHANGE_OPCODE_COMMON
#undef CASE_VFMA_SPLATS
#undef CASE_VFMA_OPCODE_LMULS
#undef CASE_VFMA_OPCODE_COMMON
// clang-format off
#define CASE_WIDEOP_OPCODE_COMMON(OP, LMUL) \
RISCV::PseudoV##OP##_##LMUL##_TIED
#define CASE_WIDEOP_OPCODE_LMULS_MF4(OP) \
CASE_WIDEOP_OPCODE_COMMON(OP, MF4): \
case CASE_WIDEOP_OPCODE_COMMON(OP, MF2): \
case CASE_WIDEOP_OPCODE_COMMON(OP, M1): \
case CASE_WIDEOP_OPCODE_COMMON(OP, M2): \
case CASE_WIDEOP_OPCODE_COMMON(OP, M4)
#define CASE_WIDEOP_OPCODE_LMULS(OP) \
CASE_WIDEOP_OPCODE_COMMON(OP, MF8): \
case CASE_WIDEOP_OPCODE_LMULS_MF4(OP)
// clang-format on
#define CASE_WIDEOP_CHANGE_OPCODE_COMMON(OP, LMUL) \
case RISCV::PseudoV##OP##_##LMUL##_TIED: \
NewOpc = RISCV::PseudoV##OP##_##LMUL; \
break;
#define CASE_WIDEOP_CHANGE_OPCODE_LMULS_MF4(OP) \
CASE_WIDEOP_CHANGE_OPCODE_COMMON(OP, MF4) \
CASE_WIDEOP_CHANGE_OPCODE_COMMON(OP, MF2) \
CASE_WIDEOP_CHANGE_OPCODE_COMMON(OP, M1) \
CASE_WIDEOP_CHANGE_OPCODE_COMMON(OP, M2) \
CASE_WIDEOP_CHANGE_OPCODE_COMMON(OP, M4)
#define CASE_WIDEOP_CHANGE_OPCODE_LMULS(OP) \
CASE_WIDEOP_CHANGE_OPCODE_COMMON(OP, MF8) \
CASE_WIDEOP_CHANGE_OPCODE_LMULS_MF4(OP)
MachineInstr *RISCVInstrInfo::convertToThreeAddress(MachineInstr &MI,
LiveVariables *LV,
LiveIntervals *LIS) const {
switch (MI.getOpcode()) {
default:
break;
case CASE_WIDEOP_OPCODE_LMULS_MF4(FWADD_WV):
case CASE_WIDEOP_OPCODE_LMULS_MF4(FWSUB_WV):
case CASE_WIDEOP_OPCODE_LMULS(WADD_WV):
case CASE_WIDEOP_OPCODE_LMULS(WADDU_WV):
case CASE_WIDEOP_OPCODE_LMULS(WSUB_WV):
case CASE_WIDEOP_OPCODE_LMULS(WSUBU_WV): {
// If the tail policy is undisturbed we can't convert.
assert(RISCVII::hasVecPolicyOp(MI.getDesc().TSFlags) &&
MI.getNumExplicitOperands() == 6);
if ((MI.getOperand(5).getImm() & 1) == 0)
return nullptr;
// clang-format off
unsigned NewOpc;
switch (MI.getOpcode()) {
default:
llvm_unreachable("Unexpected opcode");
CASE_WIDEOP_CHANGE_OPCODE_LMULS_MF4(FWADD_WV)
CASE_WIDEOP_CHANGE_OPCODE_LMULS_MF4(FWSUB_WV)
CASE_WIDEOP_CHANGE_OPCODE_LMULS(WADD_WV)
CASE_WIDEOP_CHANGE_OPCODE_LMULS(WADDU_WV)
CASE_WIDEOP_CHANGE_OPCODE_LMULS(WSUB_WV)
CASE_WIDEOP_CHANGE_OPCODE_LMULS(WSUBU_WV)
}
// clang-format on
MachineBasicBlock &MBB = *MI.getParent();
MachineInstrBuilder MIB = BuildMI(MBB, MI, MI.getDebugLoc(), get(NewOpc))
.add(MI.getOperand(0))
.add(MI.getOperand(1))
.add(MI.getOperand(2))
.add(MI.getOperand(3))
.add(MI.getOperand(4));
MIB.copyImplicitOps(MI);
if (LV) {
unsigned NumOps = MI.getNumOperands();
for (unsigned I = 1; I < NumOps; ++I) {
MachineOperand &Op = MI.getOperand(I);
if (Op.isReg() && Op.isKill())
LV->replaceKillInstruction(Op.getReg(), MI, *MIB);
}
}
if (LIS) {
SlotIndex Idx = LIS->ReplaceMachineInstrInMaps(MI, *MIB);
if (MI.getOperand(0).isEarlyClobber()) {
// Use operand 1 was tied to early-clobber def operand 0, so its live
// interval could have ended at an early-clobber slot. Now they are not
// tied we need to update it to the normal register slot.
LiveInterval &LI = LIS->getInterval(MI.getOperand(1).getReg());
LiveRange::Segment *S = LI.getSegmentContaining(Idx);
if (S->end == Idx.getRegSlot(true))
S->end = Idx.getRegSlot();
}
}
return MIB;
}
}
return nullptr;
}
#undef CASE_WIDEOP_CHANGE_OPCODE_LMULS
#undef CASE_WIDEOP_CHANGE_OPCODE_COMMON
#undef CASE_WIDEOP_OPCODE_LMULS
#undef CASE_WIDEOP_OPCODE_COMMON
void RISCVInstrInfo::getVLENFactoredAmount(MachineFunction &MF,
MachineBasicBlock &MBB,
MachineBasicBlock::iterator II,
const DebugLoc &DL, Register DestReg,
int64_t Amount,
MachineInstr::MIFlag Flag) const {
assert(Amount > 0 && "There is no need to get VLEN scaled value.");
assert(Amount % 8 == 0 &&
"Reserve the stack by the multiple of one vector size.");
MachineRegisterInfo &MRI = MF.getRegInfo();
int64_t NumOfVReg = Amount / 8;
BuildMI(MBB, II, DL, get(RISCV::PseudoReadVLENB), DestReg).setMIFlag(Flag);
assert(isInt<32>(NumOfVReg) &&
"Expect the number of vector registers within 32-bits.");
if (isPowerOf2_32(NumOfVReg)) {
uint32_t ShiftAmount = Log2_32(NumOfVReg);
if (ShiftAmount == 0)
return;
BuildMI(MBB, II, DL, get(RISCV::SLLI), DestReg)
.addReg(DestReg, RegState::Kill)
.addImm(ShiftAmount)
.setMIFlag(Flag);
} else if (STI.hasStdExtZba() &&
((NumOfVReg % 3 == 0 && isPowerOf2_64(NumOfVReg / 3)) ||
(NumOfVReg % 5 == 0 && isPowerOf2_64(NumOfVReg / 5)) ||
(NumOfVReg % 9 == 0 && isPowerOf2_64(NumOfVReg / 9)))) {
// We can use Zba SHXADD+SLLI instructions for multiply in some cases.
unsigned Opc;
uint32_t ShiftAmount;
if (NumOfVReg % 9 == 0) {
Opc = RISCV::SH3ADD;
ShiftAmount = Log2_64(NumOfVReg / 9);
} else if (NumOfVReg % 5 == 0) {
Opc = RISCV::SH2ADD;
ShiftAmount = Log2_64(NumOfVReg / 5);
} else if (NumOfVReg % 3 == 0) {
Opc = RISCV::SH1ADD;
ShiftAmount = Log2_64(NumOfVReg / 3);
} else {
llvm_unreachable("Unexpected number of vregs");
}
if (ShiftAmount)
BuildMI(MBB, II, DL, get(RISCV::SLLI), DestReg)
.addReg(DestReg, RegState::Kill)
.addImm(ShiftAmount)
.setMIFlag(Flag);
BuildMI(MBB, II, DL, get(Opc), DestReg)
.addReg(DestReg, RegState::Kill)
.addReg(DestReg)
.setMIFlag(Flag);
} else if (isPowerOf2_32(NumOfVReg - 1)) {
Register ScaledRegister = MRI.createVirtualRegister(&RISCV::GPRRegClass);
uint32_t ShiftAmount = Log2_32(NumOfVReg - 1);
BuildMI(MBB, II, DL, get(RISCV::SLLI), ScaledRegister)
.addReg(DestReg)
.addImm(ShiftAmount)
.setMIFlag(Flag);
BuildMI(MBB, II, DL, get(RISCV::ADD), DestReg)
.addReg(ScaledRegister, RegState::Kill)
.addReg(DestReg, RegState::Kill)
.setMIFlag(Flag);
} else if (isPowerOf2_32(NumOfVReg + 1)) {
Register ScaledRegister = MRI.createVirtualRegister(&RISCV::GPRRegClass);
uint32_t ShiftAmount = Log2_32(NumOfVReg + 1);
BuildMI(MBB, II, DL, get(RISCV::SLLI), ScaledRegister)
.addReg(DestReg)
.addImm(ShiftAmount)
.setMIFlag(Flag);
BuildMI(MBB, II, DL, get(RISCV::SUB), DestReg)
.addReg(ScaledRegister, RegState::Kill)
.addReg(DestReg, RegState::Kill)
.setMIFlag(Flag);
} else {
Register N = MRI.createVirtualRegister(&RISCV::GPRRegClass);
movImm(MBB, II, DL, N, NumOfVReg, Flag);
if (!STI.hasStdExtM() && !STI.hasStdExtZmmul())
MF.getFunction().getContext().diagnose(DiagnosticInfoUnsupported{
MF.getFunction(),
"M- or Zmmul-extension must be enabled to calculate the vscaled size/"
"offset."});
BuildMI(MBB, II, DL, get(RISCV::MUL), DestReg)
.addReg(DestReg, RegState::Kill)
.addReg(N, RegState::Kill)
.setMIFlag(Flag);
}
}
// Checks if all users only demand the lower \p OrigBits of the original
// instruction's result.
// TODO: handle multiple interdependent transformations
bool RISCVInstrInfo::hasAllNBitUsers(const MachineInstr &OrigMI,
const MachineRegisterInfo &MRI,
unsigned OrigBits) const {
SmallSet<std::pair<const MachineInstr *, unsigned>, 4> Visited;
SmallVector<std::pair<const MachineInstr *, unsigned>, 4> Worklist;
Worklist.push_back(std::make_pair(&OrigMI, OrigBits));
while (!Worklist.empty()) {
auto P = Worklist.pop_back_val();
const MachineInstr *MI = P.first;
unsigned Bits = P.second;
if (!Visited.insert(P).second)
continue;
// Only handle instructions with one def.
if (MI->getNumExplicitDefs() != 1)
return false;
for (auto &UserOp : MRI.use_operands(MI->getOperand(0).getReg())) {
const MachineInstr *UserMI = UserOp.getParent();
unsigned OpIdx = UserMI->getOperandNo(&UserOp);
switch (UserMI->getOpcode()) {
default:
return false;
case RISCV::ADDIW:
case RISCV::ADDW:
case RISCV::DIVUW:
case RISCV::DIVW:
case RISCV::MULW:
case RISCV::REMUW:
case RISCV::REMW:
case RISCV::SLLIW:
case RISCV::SLLW:
case RISCV::SRAIW:
case RISCV::SRAW:
case RISCV::SRLIW:
case RISCV::SRLW:
case RISCV::SUBW:
case RISCV::ROLW:
case RISCV::RORW:
case RISCV::RORIW:
case RISCV::CLZW:
case RISCV::CTZW:
case RISCV::CPOPW:
case RISCV::SLLI_UW:
case RISCV::FMV_W_X:
case RISCV::FCVT_H_W:
case RISCV::FCVT_H_WU:
case RISCV::FCVT_S_W:
case RISCV::FCVT_S_WU:
case RISCV::FCVT_D_W:
case RISCV::FCVT_D_WU:
if (Bits >= 32)
break;
return false;
case RISCV::SEXT_B:
case RISCV::PACKH:
if (Bits >= 8)
break;
return false;
case RISCV::SEXT_H:
case RISCV::FMV_H_X:
case RISCV::ZEXT_H_RV32:
case RISCV::ZEXT_H_RV64:
case RISCV::PACKW:
if (Bits >= 16)
break;
return false;
case RISCV::PACK:
if (Bits >= (STI.getXLen() / 2))
break;
return false;
case RISCV::SRLI: {
// If we are shifting right by less than Bits, and users don't demand
// any bits that were shifted into [Bits-1:0], then we can consider this
// as an N-Bit user.
unsigned ShAmt = UserMI->getOperand(2).getImm();
if (Bits > ShAmt) {
Worklist.push_back(std::make_pair(UserMI, Bits - ShAmt));
break;
}
return false;
}
// these overwrite higher input bits, otherwise the lower word of output
// depends only on the lower word of input. So check their uses read W.
case RISCV::SLLI:
if (Bits >= (STI.getXLen() - UserMI->getOperand(2).getImm()))
break;
Worklist.push_back(std::make_pair(UserMI, Bits));
break;
case RISCV::ANDI: {
uint64_t Imm = UserMI->getOperand(2).getImm();
if (Bits >= (unsigned)llvm::bit_width(Imm))
break;
Worklist.push_back(std::make_pair(UserMI, Bits));
break;
}
case RISCV::ORI: {
uint64_t Imm = UserMI->getOperand(2).getImm();
if (Bits >= (unsigned)llvm::bit_width<uint64_t>(~Imm))
break;
Worklist.push_back(std::make_pair(UserMI, Bits));
break;
}
case RISCV::SLL:
case RISCV::BSET:
case RISCV::BCLR:
case RISCV::BINV:
// Operand 2 is the shift amount which uses log2(xlen) bits.
if (OpIdx == 2) {
if (Bits >= Log2_32(STI.getXLen()))
break;
return false;
}
Worklist.push_back(std::make_pair(UserMI, Bits));
break;
case RISCV::SRA:
case RISCV::SRL:
case RISCV::ROL:
case RISCV::ROR:
// Operand 2 is the shift amount which uses 6 bits.
if (OpIdx == 2 && Bits >= Log2_32(STI.getXLen()))
break;
return false;
case RISCV::ADD_UW:
case RISCV::SH1ADD_UW:
case RISCV::SH2ADD_UW:
case RISCV::SH3ADD_UW:
// Operand 1 is implicitly zero extended.
if (OpIdx == 1 && Bits >= 32)
break;
Worklist.push_back(std::make_pair(UserMI, Bits));
break;
case RISCV::BEXTI:
if (UserMI->getOperand(2).getImm() >= Bits)
return false;
break;
case RISCV::SB:
// The first argument is the value to store.
if (OpIdx == 0 && Bits >= 8)
break;
return false;
case RISCV::SH:
// The first argument is the value to store.
if (OpIdx == 0 && Bits >= 16)
break;
return false;
case RISCV::SW:
// The first argument is the value to store.
if (OpIdx == 0 && Bits >= 32)
break;
return false;
// For these, lower word of output in these operations, depends only on
// the lower word of input. So, we check all uses only read lower word.
case RISCV::COPY:
case RISCV::PHI:
case RISCV::ADD:
case RISCV::ADDI:
case RISCV::AND:
case RISCV::MUL:
case RISCV::OR:
case RISCV::SUB:
case RISCV::XOR:
case RISCV::XORI:
case RISCV::ANDN:
case RISCV::BREV8:
case RISCV::CLMUL:
case RISCV::ORC_B:
case RISCV::ORN:
case RISCV::SH1ADD:
case RISCV::SH2ADD:
case RISCV::SH3ADD:
case RISCV::XNOR:
case RISCV::BSETI:
case RISCV::BCLRI:
case RISCV::BINVI:
Worklist.push_back(std::make_pair(UserMI, Bits));
break;
case RISCV::PseudoCCMOVGPR:
// Either operand 4 or operand 5 is returned by this instruction. If
// only the lower word of the result is used, then only the lower word
// of operand 4 and 5 is used.
if (OpIdx != 4 && OpIdx != 5)
return false;
Worklist.push_back(std::make_pair(UserMI, Bits));
break;
case RISCV::VT_MASKC:
case RISCV::VT_MASKCN:
if (OpIdx != 1)
return false;
Worklist.push_back(std::make_pair(UserMI, Bits));
break;
}
}
}
return true;
}
// Returns true if this is the sext.w pattern, addiw rd, rs1, 0.
bool RISCV::isSEXT_W(const MachineInstr &MI) {
return MI.getOpcode() == RISCV::ADDIW && MI.getOperand(1).isReg() &&
MI.getOperand(2).isImm() && MI.getOperand(2).getImm() == 0;
}
// Returns true if this is the zext.w pattern, adduw rd, rs1, x0.
bool RISCV::isZEXT_W(const MachineInstr &MI) {
return MI.getOpcode() == RISCV::ADD_UW && MI.getOperand(1).isReg() &&
MI.getOperand(2).isReg() && MI.getOperand(2).getReg() == RISCV::X0;
}
// Returns true if this is the zext.b pattern, andi rd, rs1, 255.
bool RISCV::isZEXT_B(const MachineInstr &MI) {
return MI.getOpcode() == RISCV::ANDI && MI.getOperand(1).isReg() &&
MI.getOperand(2).isImm() && MI.getOperand(2).getImm() == 255;
}
static bool isRVVWholeLoadStore(unsigned Opcode) {
switch (Opcode) {
default:
return false;
case RISCV::VS1R_V:
case RISCV::VS2R_V:
case RISCV::VS4R_V:
case RISCV::VS8R_V:
case RISCV::VL1RE8_V:
case RISCV::VL2RE8_V:
case RISCV::VL4RE8_V:
case RISCV::VL8RE8_V:
case RISCV::VL1RE16_V:
case RISCV::VL2RE16_V:
case RISCV::VL4RE16_V:
case RISCV::VL8RE16_V:
case RISCV::VL1RE32_V:
case RISCV::VL2RE32_V:
case RISCV::VL4RE32_V:
case RISCV::VL8RE32_V:
case RISCV::VL1RE64_V:
case RISCV::VL2RE64_V:
case RISCV::VL4RE64_V:
case RISCV::VL8RE64_V:
return true;
}
}
bool RISCV::isRVVSpill(const MachineInstr &MI) {
// RVV lacks any support for immediate addressing for stack addresses, so be
// conservative.
unsigned Opcode = MI.getOpcode();
if (!RISCVVPseudosTable::getPseudoInfo(Opcode) &&
!isRVVWholeLoadStore(Opcode) && !isRVVSpillForZvlsseg(Opcode))
return false;
return true;
}
std::optional<std::pair<unsigned, unsigned>>
RISCV::isRVVSpillForZvlsseg(unsigned Opcode) {
switch (Opcode) {
default:
return std::nullopt;
case RISCV::PseudoVSPILL2_M1:
case RISCV::PseudoVRELOAD2_M1:
return std::make_pair(2u, 1u);
case RISCV::PseudoVSPILL2_M2:
case RISCV::PseudoVRELOAD2_M2:
return std::make_pair(2u, 2u);
case RISCV::PseudoVSPILL2_M4:
case RISCV::PseudoVRELOAD2_M4:
return std::make_pair(2u, 4u);
case RISCV::PseudoVSPILL3_M1:
case RISCV::PseudoVRELOAD3_M1:
return std::make_pair(3u, 1u);
case RISCV::PseudoVSPILL3_M2:
case RISCV::PseudoVRELOAD3_M2:
return std::make_pair(3u, 2u);
case RISCV::PseudoVSPILL4_M1:
case RISCV::PseudoVRELOAD4_M1:
return std::make_pair(4u, 1u);
case RISCV::PseudoVSPILL4_M2:
case RISCV::PseudoVRELOAD4_M2:
return std::make_pair(4u, 2u);
case RISCV::PseudoVSPILL5_M1:
case RISCV::PseudoVRELOAD5_M1:
return std::make_pair(5u, 1u);
case RISCV::PseudoVSPILL6_M1:
case RISCV::PseudoVRELOAD6_M1:
return std::make_pair(6u, 1u);
case RISCV::PseudoVSPILL7_M1:
case RISCV::PseudoVRELOAD7_M1:
return std::make_pair(7u, 1u);
case RISCV::PseudoVSPILL8_M1:
case RISCV::PseudoVRELOAD8_M1:
return std::make_pair(8u, 1u);
}
}
bool RISCV::isFaultFirstLoad(const MachineInstr &MI) {
return MI.getNumExplicitDefs() == 2 && MI.modifiesRegister(RISCV::VL) &&
!MI.isInlineAsm();
}
bool RISCV::hasEqualFRM(const MachineInstr &MI1, const MachineInstr &MI2) {
int16_t MI1FrmOpIdx =
RISCV::getNamedOperandIdx(MI1.getOpcode(), RISCV::OpName::frm);
int16_t MI2FrmOpIdx =
RISCV::getNamedOperandIdx(MI2.getOpcode(), RISCV::OpName::frm);
if (MI1FrmOpIdx < 0 || MI2FrmOpIdx < 0)
return false;
MachineOperand FrmOp1 = MI1.getOperand(MI1FrmOpIdx);
MachineOperand FrmOp2 = MI2.getOperand(MI2FrmOpIdx);
return FrmOp1.getImm() == FrmOp2.getImm();
}