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llvm-mirror/lib/Target/Lanai/LanaiInstrInfo.cpp
hsmahesha ed5decd2c8 [AMDGPU/MemOpsCluster] Let mem ops clustering logic also consider number of clustered bytes 
Summary:
While clustering mem ops, AMDGPU target needs to consider number of clustered bytes
to decide on max number of mem ops that can be clustered. This patch adds support to pass
number of clustered bytes to target mem ops clustering logic.

Reviewers: foad, rampitec, arsenm, vpykhtin, javedabsar

Reviewed By: foad

Subscribers: MatzeB, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, javed.absar, kerbowa, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80545
2020-06-01 22:52:34 +05:30

822 lines
27 KiB
C++
Raw Blame History

//===-- LanaiInstrInfo.cpp - Lanai 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 Lanai implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "LanaiInstrInfo.h"
#include "LanaiAluCode.h"
#include "LanaiCondCode.h"
#include "MCTargetDesc/LanaiBaseInfo.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/TargetRegistry.h"
using namespace llvm;
#define GET_INSTRINFO_CTOR_DTOR
#include "LanaiGenInstrInfo.inc"
LanaiInstrInfo::LanaiInstrInfo()
: LanaiGenInstrInfo(Lanai::ADJCALLSTACKDOWN, Lanai::ADJCALLSTACKUP),
RegisterInfo() {}
void LanaiInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator Position,
const DebugLoc &DL,
MCRegister DestinationRegister,
MCRegister SourceRegister,
bool KillSource) const {
if (!Lanai::GPRRegClass.contains(DestinationRegister, SourceRegister)) {
llvm_unreachable("Impossible reg-to-reg copy");
}
BuildMI(MBB, Position, DL, get(Lanai::OR_I_LO), DestinationRegister)
.addReg(SourceRegister, getKillRegState(KillSource))
.addImm(0);
}
void LanaiInstrInfo::storeRegToStackSlot(
MachineBasicBlock &MBB, MachineBasicBlock::iterator Position,
Register SourceRegister, bool IsKill, int FrameIndex,
const TargetRegisterClass *RegisterClass,
const TargetRegisterInfo * /*RegisterInfo*/) const {
DebugLoc DL;
if (Position != MBB.end()) {
DL = Position->getDebugLoc();
}
if (!Lanai::GPRRegClass.hasSubClassEq(RegisterClass)) {
llvm_unreachable("Can't store this register to stack slot");
}
BuildMI(MBB, Position, DL, get(Lanai::SW_RI))
.addReg(SourceRegister, getKillRegState(IsKill))
.addFrameIndex(FrameIndex)
.addImm(0)
.addImm(LPAC::ADD);
}
void LanaiInstrInfo::loadRegFromStackSlot(
MachineBasicBlock &MBB, MachineBasicBlock::iterator Position,
Register DestinationRegister, int FrameIndex,
const TargetRegisterClass *RegisterClass,
const TargetRegisterInfo * /*RegisterInfo*/) const {
DebugLoc DL;
if (Position != MBB.end()) {
DL = Position->getDebugLoc();
}
if (!Lanai::GPRRegClass.hasSubClassEq(RegisterClass)) {
llvm_unreachable("Can't load this register from stack slot");
}
BuildMI(MBB, Position, DL, get(Lanai::LDW_RI), DestinationRegister)
.addFrameIndex(FrameIndex)
.addImm(0)
.addImm(LPAC::ADD);
}
bool LanaiInstrInfo::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 = &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;
}
bool LanaiInstrInfo::expandPostRAPseudo(MachineInstr & /*MI*/) const {
return false;
}
static LPCC::CondCode getOppositeCondition(LPCC::CondCode CC) {
switch (CC) {
case LPCC::ICC_T: // true
return LPCC::ICC_F;
case LPCC::ICC_F: // false
return LPCC::ICC_T;
case LPCC::ICC_HI: // high
return LPCC::ICC_LS;
case LPCC::ICC_LS: // low or same
return LPCC::ICC_HI;
case LPCC::ICC_CC: // carry cleared
return LPCC::ICC_CS;
case LPCC::ICC_CS: // carry set
return LPCC::ICC_CC;
case LPCC::ICC_NE: // not equal
return LPCC::ICC_EQ;
case LPCC::ICC_EQ: // equal
return LPCC::ICC_NE;
case LPCC::ICC_VC: // oVerflow cleared
return LPCC::ICC_VS;
case LPCC::ICC_VS: // oVerflow set
return LPCC::ICC_VC;
case LPCC::ICC_PL: // plus (note: 0 is "minus" too here)
return LPCC::ICC_MI;
case LPCC::ICC_MI: // minus
return LPCC::ICC_PL;
case LPCC::ICC_GE: // greater than or equal
return LPCC::ICC_LT;
case LPCC::ICC_LT: // less than
return LPCC::ICC_GE;
case LPCC::ICC_GT: // greater than
return LPCC::ICC_LE;
case LPCC::ICC_LE: // less than or equal
return LPCC::ICC_GT;
default:
llvm_unreachable("Invalid condtional code");
}
}
std::pair<unsigned, unsigned>
LanaiInstrInfo::decomposeMachineOperandsTargetFlags(unsigned TF) const {
return std::make_pair(TF, 0u);
}
ArrayRef<std::pair<unsigned, const char *>>
LanaiInstrInfo::getSerializableDirectMachineOperandTargetFlags() const {
using namespace LanaiII;
static const std::pair<unsigned, const char *> TargetFlags[] = {
{MO_ABS_HI, "lanai-hi"},
{MO_ABS_LO, "lanai-lo"},
{MO_NO_FLAG, "lanai-nf"}};
return makeArrayRef(TargetFlags);
}
bool LanaiInstrInfo::analyzeCompare(const MachineInstr &MI, Register &SrcReg,
Register &SrcReg2, int &CmpMask,
int &CmpValue) const {
switch (MI.getOpcode()) {
default:
break;
case Lanai::SFSUB_F_RI_LO:
case Lanai::SFSUB_F_RI_HI:
SrcReg = MI.getOperand(0).getReg();
SrcReg2 = Register();
CmpMask = ~0;
CmpValue = MI.getOperand(1).getImm();
return true;
case Lanai::SFSUB_F_RR:
SrcReg = MI.getOperand(0).getReg();
SrcReg2 = MI.getOperand(1).getReg();
CmpMask = ~0;
CmpValue = 0;
return true;
}
return false;
}
// isRedundantFlagInstr - check whether the first instruction, whose only
// purpose is to update flags, can be made redundant.
// * SFSUB_F_RR can be made redundant by SUB_RI if the operands are the same.
// * SFSUB_F_RI can be made redundant by SUB_I if the operands are the same.
inline static bool isRedundantFlagInstr(MachineInstr *CmpI, unsigned SrcReg,
unsigned SrcReg2, int ImmValue,
MachineInstr *OI) {
if (CmpI->getOpcode() == Lanai::SFSUB_F_RR &&
OI->getOpcode() == Lanai::SUB_R &&
((OI->getOperand(1).getReg() == SrcReg &&
OI->getOperand(2).getReg() == SrcReg2) ||
(OI->getOperand(1).getReg() == SrcReg2 &&
OI->getOperand(2).getReg() == SrcReg)))
return true;
if (((CmpI->getOpcode() == Lanai::SFSUB_F_RI_LO &&
OI->getOpcode() == Lanai::SUB_I_LO) ||
(CmpI->getOpcode() == Lanai::SFSUB_F_RI_HI &&
OI->getOpcode() == Lanai::SUB_I_HI)) &&
OI->getOperand(1).getReg() == SrcReg &&
OI->getOperand(2).getImm() == ImmValue)
return true;
return false;
}
inline static unsigned flagSettingOpcodeVariant(unsigned OldOpcode) {
switch (OldOpcode) {
case Lanai::ADD_I_HI:
return Lanai::ADD_F_I_HI;
case Lanai::ADD_I_LO:
return Lanai::ADD_F_I_LO;
case Lanai::ADD_R:
return Lanai::ADD_F_R;
case Lanai::ADDC_I_HI:
return Lanai::ADDC_F_I_HI;
case Lanai::ADDC_I_LO:
return Lanai::ADDC_F_I_LO;
case Lanai::ADDC_R:
return Lanai::ADDC_F_R;
case Lanai::AND_I_HI:
return Lanai::AND_F_I_HI;
case Lanai::AND_I_LO:
return Lanai::AND_F_I_LO;
case Lanai::AND_R:
return Lanai::AND_F_R;
case Lanai::OR_I_HI:
return Lanai::OR_F_I_HI;
case Lanai::OR_I_LO:
return Lanai::OR_F_I_LO;
case Lanai::OR_R:
return Lanai::OR_F_R;
case Lanai::SL_I:
return Lanai::SL_F_I;
case Lanai::SRL_R:
return Lanai::SRL_F_R;
case Lanai::SA_I:
return Lanai::SA_F_I;
case Lanai::SRA_R:
return Lanai::SRA_F_R;
case Lanai::SUB_I_HI:
return Lanai::SUB_F_I_HI;
case Lanai::SUB_I_LO:
return Lanai::SUB_F_I_LO;
case Lanai::SUB_R:
return Lanai::SUB_F_R;
case Lanai::SUBB_I_HI:
return Lanai::SUBB_F_I_HI;
case Lanai::SUBB_I_LO:
return Lanai::SUBB_F_I_LO;
case Lanai::SUBB_R:
return Lanai::SUBB_F_R;
case Lanai::XOR_I_HI:
return Lanai::XOR_F_I_HI;
case Lanai::XOR_I_LO:
return Lanai::XOR_F_I_LO;
case Lanai::XOR_R:
return Lanai::XOR_F_R;
default:
return Lanai::NOP;
}
}
bool LanaiInstrInfo::optimizeCompareInstr(
MachineInstr &CmpInstr, Register SrcReg, Register SrcReg2, int /*CmpMask*/,
int CmpValue, const MachineRegisterInfo *MRI) const {
// Get the unique definition of SrcReg.
MachineInstr *MI = MRI->getUniqueVRegDef(SrcReg);
if (!MI)
return false;
// Get ready to iterate backward from CmpInstr.
MachineBasicBlock::iterator I = CmpInstr, E = MI,
B = CmpInstr.getParent()->begin();
// Early exit if CmpInstr is at the beginning of the BB.
if (I == B)
return false;
// There are two possible candidates which can be changed to set SR:
// One is MI, the other is a SUB instruction.
// * For SFSUB_F_RR(r1,r2), we are looking for SUB(r1,r2) or SUB(r2,r1).
// * For SFSUB_F_RI(r1, CmpValue), we are looking for SUB(r1, CmpValue).
MachineInstr *Sub = nullptr;
if (SrcReg2 != 0)
// MI is not a candidate to transform into a flag setting instruction.
MI = nullptr;
else if (MI->getParent() != CmpInstr.getParent() || CmpValue != 0) {
// Conservatively refuse to convert an instruction which isn't in the same
// BB as the comparison. Don't return if SFSUB_F_RI and CmpValue != 0 as Sub
// may still be a candidate.
if (CmpInstr.getOpcode() == Lanai::SFSUB_F_RI_LO)
MI = nullptr;
else
return false;
}
// Check that SR isn't set between the comparison instruction and the
// instruction we want to change while searching for Sub.
const TargetRegisterInfo *TRI = &getRegisterInfo();
for (--I; I != E; --I) {
const MachineInstr &Instr = *I;
if (Instr.modifiesRegister(Lanai::SR, TRI) ||
Instr.readsRegister(Lanai::SR, TRI))
// This instruction modifies or uses SR after the one we want to change.
// We can't do this transformation.
return false;
// Check whether CmpInstr can be made redundant by the current instruction.
if (isRedundantFlagInstr(&CmpInstr, SrcReg, SrcReg2, CmpValue, &*I)) {
Sub = &*I;
break;
}
// Don't search outside the containing basic block.
if (I == B)
return false;
}
// Return false if no candidates exist.
if (!MI && !Sub)
return false;
// The single candidate is called MI.
if (!MI)
MI = Sub;
if (flagSettingOpcodeVariant(MI->getOpcode()) != Lanai::NOP) {
bool isSafe = false;
SmallVector<std::pair<MachineOperand *, LPCC::CondCode>, 4>
OperandsToUpdate;
I = CmpInstr;
E = CmpInstr.getParent()->end();
while (!isSafe && ++I != E) {
const MachineInstr &Instr = *I;
for (unsigned IO = 0, EO = Instr.getNumOperands(); !isSafe && IO != EO;
++IO) {
const MachineOperand &MO = Instr.getOperand(IO);
if (MO.isRegMask() && MO.clobbersPhysReg(Lanai::SR)) {
isSafe = true;
break;
}
if (!MO.isReg() || MO.getReg() != Lanai::SR)
continue;
if (MO.isDef()) {
isSafe = true;
break;
}
// Condition code is after the operand before SR.
LPCC::CondCode CC;
CC = (LPCC::CondCode)Instr.getOperand(IO - 1).getImm();
if (Sub) {
LPCC::CondCode NewCC = getOppositeCondition(CC);
if (NewCC == LPCC::ICC_T)
return false;
// If we have SUB(r1, r2) and CMP(r2, r1), the condition code based on
// CMP needs to be updated to be based on SUB. Push the condition
// code operands to OperandsToUpdate. If it is safe to remove
// CmpInstr, the condition code of these operands will be modified.
if (SrcReg2 != 0 && Sub->getOperand(1).getReg() == SrcReg2 &&
Sub->getOperand(2).getReg() == SrcReg) {
OperandsToUpdate.push_back(
std::make_pair(&((*I).getOperand(IO - 1)), NewCC));
}
} else {
// No Sub, so this is x = <op> y, z; cmp x, 0.
switch (CC) {
case LPCC::ICC_EQ: // Z
case LPCC::ICC_NE: // Z
case LPCC::ICC_MI: // N
case LPCC::ICC_PL: // N
case LPCC::ICC_F: // none
case LPCC::ICC_T: // none
// SR can be used multiple times, we should continue.
break;
case LPCC::ICC_CS: // C
case LPCC::ICC_CC: // C
case LPCC::ICC_VS: // V
case LPCC::ICC_VC: // V
case LPCC::ICC_HI: // C Z
case LPCC::ICC_LS: // C Z
case LPCC::ICC_GE: // N V
case LPCC::ICC_LT: // N V
case LPCC::ICC_GT: // Z N V
case LPCC::ICC_LE: // Z N V
// The instruction uses the V bit or C bit which is not safe.
return false;
case LPCC::UNKNOWN:
return false;
}
}
}
}
// If SR is not killed nor re-defined, we should check whether it is
// live-out. If it is live-out, do not optimize.
if (!isSafe) {
MachineBasicBlock *MBB = CmpInstr.getParent();
for (MachineBasicBlock::succ_iterator SI = MBB->succ_begin(),
SE = MBB->succ_end();
SI != SE; ++SI)
if ((*SI)->isLiveIn(Lanai::SR))
return false;
}
// Toggle the optional operand to SR.
MI->setDesc(get(flagSettingOpcodeVariant(MI->getOpcode())));
MI->addRegisterDefined(Lanai::SR);
CmpInstr.eraseFromParent();
return true;
}
return false;
}
bool LanaiInstrInfo::analyzeSelect(const MachineInstr &MI,
SmallVectorImpl<MachineOperand> &Cond,
unsigned &TrueOp, unsigned &FalseOp,
bool &Optimizable) const {
assert(MI.getOpcode() == Lanai::SELECT && "unknown select instruction");
// Select operands:
// 0: Def.
// 1: True use.
// 2: False use.
// 3: Condition code.
TrueOp = 1;
FalseOp = 2;
Cond.push_back(MI.getOperand(3));
Optimizable = true;
return false;
}
// Identify instructions that can be folded into a SELECT instruction, and
// return the defining instruction.
static MachineInstr *canFoldIntoSelect(Register Reg,
const MachineRegisterInfo &MRI) {
if (!Reg.isVirtual())
return nullptr;
if (!MRI.hasOneNonDBGUse(Reg))
return nullptr;
MachineInstr *MI = MRI.getVRegDef(Reg);
if (!MI)
return nullptr;
// MI is folded into the SELECT by predicating it.
if (!MI->isPredicable())
return nullptr;
// Check if MI has any non-dead defs or physreg uses. This also detects
// predicated instructions which will be reading SR.
for (unsigned i = 1, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
// Reject frame index operands.
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 (Register::isPhysicalRegister(MO.getReg()))
return nullptr;
if (MO.isDef() && !MO.isDead())
return nullptr;
}
bool DontMoveAcrossStores = true;
if (!MI->isSafeToMove(/*AliasAnalysis=*/nullptr, DontMoveAcrossStores))
return nullptr;
return MI;
}
MachineInstr *
LanaiInstrInfo::optimizeSelect(MachineInstr &MI,
SmallPtrSetImpl<MachineInstr *> &SeenMIs,
bool /*PreferFalse*/) const {
assert(MI.getOpcode() == Lanai::SELECT && "unknown select instruction");
MachineRegisterInfo &MRI = MI.getParent()->getParent()->getRegInfo();
MachineInstr *DefMI = canFoldIntoSelect(MI.getOperand(1).getReg(), MRI);
bool Invert = !DefMI;
if (!DefMI)
DefMI = canFoldIntoSelect(MI.getOperand(2).getReg(), MRI);
if (!DefMI)
return nullptr;
// Find new register class to use.
MachineOperand FalseReg = MI.getOperand(Invert ? 1 : 2);
Register DestReg = MI.getOperand(0).getReg();
const TargetRegisterClass *PreviousClass = MRI.getRegClass(FalseReg.getReg());
if (!MRI.constrainRegClass(DestReg, PreviousClass))
return nullptr;
// Create a new predicated version of DefMI.
MachineInstrBuilder NewMI =
BuildMI(*MI.getParent(), MI, MI.getDebugLoc(), DefMI->getDesc(), DestReg);
// Copy all the DefMI operands, excluding its (null) predicate.
const MCInstrDesc &DefDesc = DefMI->getDesc();
for (unsigned i = 1, e = DefDesc.getNumOperands();
i != e && !DefDesc.OpInfo[i].isPredicate(); ++i)
NewMI.add(DefMI->getOperand(i));
unsigned CondCode = MI.getOperand(3).getImm();
if (Invert)
NewMI.addImm(getOppositeCondition(LPCC::CondCode(CondCode)));
else
NewMI.addImm(CondCode);
NewMI.copyImplicitOps(MI);
// The output register value when the predicate is false is an implicit
// register operand tied to the first def. The tie makes the register
// allocator ensure the FalseReg is allocated the same register as operand 0.
FalseReg.setImplicit();
NewMI.add(FalseReg);
NewMI->tieOperands(0, NewMI->getNumOperands() - 1);
// 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 transferred 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;
}
// The analyzeBranch function is used to examine conditional instructions and
// remove unnecessary instructions. This method is used by BranchFolder and
// IfConverter machine function passes to improve the CFG.
// - TrueBlock is set to the destination if condition evaluates true (it is the
// nullptr if the destination is the fall-through branch);
// - FalseBlock is set to the destination if condition evaluates to false (it
// is the nullptr if the branch is unconditional);
// - condition is populated with machine operands needed to generate the branch
// to insert in insertBranch;
// Returns: false if branch could successfully be analyzed.
bool LanaiInstrInfo::analyzeBranch(MachineBasicBlock &MBB,
MachineBasicBlock *&TrueBlock,
MachineBasicBlock *&FalseBlock,
SmallVectorImpl<MachineOperand> &Condition,
bool AllowModify) const {
// Iterator to current instruction being considered.
MachineBasicBlock::iterator Instruction = MBB.end();
// Start from the bottom of the block and work up, examining the
// terminator instructions.
while (Instruction != MBB.begin()) {
--Instruction;
// Skip over debug instructions.
if (Instruction->isDebugInstr())
continue;
// Working from the bottom, when we see a non-terminator
// instruction, we're done.
if (!isUnpredicatedTerminator(*Instruction))
break;
// A terminator that isn't a branch can't easily be handled
// by this analysis.
if (!Instruction->isBranch())
return true;
// Handle unconditional branches.
if (Instruction->getOpcode() == Lanai::BT) {
if (!AllowModify) {
TrueBlock = Instruction->getOperand(0).getMBB();
continue;
}
// If the block has any instructions after a branch, delete them.
while (std::next(Instruction) != MBB.end()) {
std::next(Instruction)->eraseFromParent();
}
Condition.clear();
FalseBlock = nullptr;
// Delete the jump if it's equivalent to a fall-through.
if (MBB.isLayoutSuccessor(Instruction->getOperand(0).getMBB())) {
TrueBlock = nullptr;
Instruction->eraseFromParent();
Instruction = MBB.end();
continue;
}
// TrueBlock is used to indicate the unconditional destination.
TrueBlock = Instruction->getOperand(0).getMBB();
continue;
}
// Handle conditional branches
unsigned Opcode = Instruction->getOpcode();
if (Opcode != Lanai::BRCC)
return true; // Unknown opcode.
// Multiple conditional branches are not handled here so only proceed if
// there are no conditions enqueued.
if (Condition.empty()) {
LPCC::CondCode BranchCond =
static_cast<LPCC::CondCode>(Instruction->getOperand(1).getImm());
// TrueBlock is the target of the previously seen unconditional branch.
FalseBlock = TrueBlock;
TrueBlock = Instruction->getOperand(0).getMBB();
Condition.push_back(MachineOperand::CreateImm(BranchCond));
continue;
}
// Multiple conditional branches are not handled.
return true;
}
// Return false indicating branch successfully analyzed.
return false;
}
// reverseBranchCondition - Reverses the branch condition of the specified
// condition list, returning false on success and true if it cannot be
// reversed.
bool LanaiInstrInfo::reverseBranchCondition(
SmallVectorImpl<llvm::MachineOperand> &Condition) const {
assert((Condition.size() == 1) &&
"Lanai branch conditions should have one component.");
LPCC::CondCode BranchCond =
static_cast<LPCC::CondCode>(Condition[0].getImm());
Condition[0].setImm(getOppositeCondition(BranchCond));
return false;
}
// Insert the branch with condition specified in condition and given targets
// (TrueBlock and FalseBlock). This function returns the number of machine
// instructions inserted.
unsigned LanaiInstrInfo::insertBranch(MachineBasicBlock &MBB,
MachineBasicBlock *TrueBlock,
MachineBasicBlock *FalseBlock,
ArrayRef<MachineOperand> Condition,
const DebugLoc &DL,
int *BytesAdded) const {
// Shouldn't be a fall through.
assert(TrueBlock && "insertBranch must not be told to insert a fallthrough");
assert(!BytesAdded && "code size not handled");
// If condition is empty then an unconditional branch is being inserted.
if (Condition.empty()) {
assert(!FalseBlock && "Unconditional branch with multiple successors!");
BuildMI(&MBB, DL, get(Lanai::BT)).addMBB(TrueBlock);
return 1;
}
// Else a conditional branch is inserted.
assert((Condition.size() == 1) &&
"Lanai branch conditions should have one component.");
unsigned ConditionalCode = Condition[0].getImm();
BuildMI(&MBB, DL, get(Lanai::BRCC)).addMBB(TrueBlock).addImm(ConditionalCode);
// If no false block, then false behavior is fall through and no branch needs
// to be inserted.
if (!FalseBlock)
return 1;
BuildMI(&MBB, DL, get(Lanai::BT)).addMBB(FalseBlock);
return 2;
}
unsigned LanaiInstrInfo::removeBranch(MachineBasicBlock &MBB,
int *BytesRemoved) const {
assert(!BytesRemoved && "code size not handled");
MachineBasicBlock::iterator Instruction = MBB.end();
unsigned Count = 0;
while (Instruction != MBB.begin()) {
--Instruction;
if (Instruction->isDebugInstr())
continue;
if (Instruction->getOpcode() != Lanai::BT &&
Instruction->getOpcode() != Lanai::BRCC) {
break;
}
// Remove the branch.
Instruction->eraseFromParent();
Instruction = MBB.end();
++Count;
}
return Count;
}
unsigned LanaiInstrInfo::isLoadFromStackSlot(const MachineInstr &MI,
int &FrameIndex) const {
if (MI.getOpcode() == Lanai::LDW_RI)
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 LanaiInstrInfo::isLoadFromStackSlotPostFE(const MachineInstr &MI,
int &FrameIndex) const {
if (MI.getOpcode() == Lanai::LDW_RI) {
unsigned Reg;
if ((Reg = isLoadFromStackSlot(MI, FrameIndex)))
return Reg;
// Check for post-frame index elimination operations
SmallVector<const MachineMemOperand *, 1> Accesses;
if (hasLoadFromStackSlot(MI, Accesses)){
FrameIndex =
cast<FixedStackPseudoSourceValue>(Accesses.front()->getPseudoValue())
->getFrameIndex();
return 1;
}
}
return 0;
}
unsigned LanaiInstrInfo::isStoreToStackSlot(const MachineInstr &MI,
int &FrameIndex) const {
if (MI.getOpcode() == Lanai::SW_RI)
if (MI.getOperand(0).isFI() && MI.getOperand(1).isImm() &&
MI.getOperand(1).getImm() == 0) {
FrameIndex = MI.getOperand(0).getIndex();
return MI.getOperand(2).getReg();
}
return 0;
}
bool LanaiInstrInfo::getMemOperandWithOffsetWidth(
const MachineInstr &LdSt, const MachineOperand *&BaseOp, int64_t &Offset,
unsigned &Width, const TargetRegisterInfo * /*TRI*/) const {
// Handle only loads/stores with base register followed by immediate offset
// and with add as ALU op.
if (LdSt.getNumOperands() != 4)
return false;
if (!LdSt.getOperand(1).isReg() || !LdSt.getOperand(2).isImm() ||
!(LdSt.getOperand(3).isImm() && LdSt.getOperand(3).getImm() == LPAC::ADD))
return false;
switch (LdSt.getOpcode()) {
default:
return false;
case Lanai::LDW_RI:
case Lanai::LDW_RR:
case Lanai::SW_RR:
case Lanai::SW_RI:
Width = 4;
break;
case Lanai::LDHs_RI:
case Lanai::LDHz_RI:
case Lanai::STH_RI:
Width = 2;
break;
case Lanai::LDBs_RI:
case Lanai::LDBz_RI:
case Lanai::STB_RI:
Width = 1;
break;
}
BaseOp = &LdSt.getOperand(1);
Offset = LdSt.getOperand(2).getImm();
if (!BaseOp->isReg())
return false;
return true;
}
bool LanaiInstrInfo::getMemOperandsWithOffsetWidth(
const MachineInstr &LdSt, SmallVectorImpl<const MachineOperand *> &BaseOps,
int64_t &Offset, bool &OffsetIsScalable, unsigned &Width,
const TargetRegisterInfo *TRI) const {
switch (LdSt.getOpcode()) {
default:
return false;
case Lanai::LDW_RI:
case Lanai::LDW_RR:
case Lanai::SW_RR:
case Lanai::SW_RI:
case Lanai::LDHs_RI:
case Lanai::LDHz_RI:
case Lanai::STH_RI:
case Lanai::LDBs_RI:
case Lanai::LDBz_RI:
const MachineOperand *BaseOp;
OffsetIsScalable = false;
if (!getMemOperandWithOffsetWidth(LdSt, BaseOp, Offset, Width, TRI))
return false;
BaseOps.push_back(BaseOp);
return true;
}
}
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