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llvm-mirror/lib/Target/Mips/MipsExpandPseudo.cpp
Aleksandar Beserminji 0c6deeab94 [mips] Fix atomic operations at O0, v3
Similar to PR/25526, fast-regalloc introduces spills at the end of basic
blocks. When this occurs in between an ll and sc, the stores can cause the
atomic sequence to fail.

This patch fixes the issue by introducing more pseudos to represent atomic
operations and moving their lowering to after the expansion of postRA
pseudos.

This version addresses issues with the initial implementation and covers
all atomic operations.

This resolves PR/32020.

Thanks to James Cowgill for reporting the issue!

Patch By: Simon Dardis

Differential Revision: https://reviews.llvm.org/D31287

llvm-svn: 336328
2018-07-05 09:27:05 +00:00

703 lines
23 KiB
C++

//===-- MipsExpandPseudoInsts.cpp - Expand pseudo instructions ------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains a pass that expands pseudo instructions into target
// instructions to allow proper scheduling, if-conversion, and other late
// optimizations. This pass should be run after register allocation but before
// the post-regalloc scheduling pass.
//
// This is currently only used for expanding atomic pseudos after register
// allocation. We do this to avoid the fast register allocator introducing
// spills between ll and sc. These stores cause some MIPS implementations to
// abort the atomic RMW sequence.
//
//===----------------------------------------------------------------------===//
#include "Mips.h"
#include "MipsInstrInfo.h"
#include "MipsSubtarget.h"
#include "llvm/CodeGen/LivePhysRegs.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
using namespace llvm;
#define DEBUG_TYPE "mips-pseudo"
namespace {
class MipsExpandPseudo : public MachineFunctionPass {
public:
static char ID;
MipsExpandPseudo() : MachineFunctionPass(ID) {}
const MipsInstrInfo *TII;
const MipsSubtarget *STI;
bool runOnMachineFunction(MachineFunction &Fn) override;
MachineFunctionProperties getRequiredProperties() const override {
return MachineFunctionProperties().set(
MachineFunctionProperties::Property::NoVRegs);
}
StringRef getPassName() const override {
return "Mips pseudo instruction expansion pass";
}
private:
bool expandAtomicCmpSwap(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
MachineBasicBlock::iterator &NextMBBI);
bool expandAtomicCmpSwapSubword(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
MachineBasicBlock::iterator &NextMBBI);
bool expandAtomicBinOp(MachineBasicBlock &BB,
MachineBasicBlock::iterator I,
MachineBasicBlock::iterator &NMBBI, unsigned Size);
bool expandAtomicBinOpSubword(MachineBasicBlock &BB,
MachineBasicBlock::iterator I,
MachineBasicBlock::iterator &NMBBI);
bool expandMI(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
MachineBasicBlock::iterator &NMBB);
bool expandMBB(MachineBasicBlock &MBB);
};
char MipsExpandPseudo::ID = 0;
}
bool MipsExpandPseudo::expandAtomicCmpSwapSubword(
MachineBasicBlock &BB, MachineBasicBlock::iterator I,
MachineBasicBlock::iterator &NMBBI) {
MachineFunction *MF = BB.getParent();
const bool ArePtrs64bit = STI->getABI().ArePtrs64bit();
DebugLoc DL = I->getDebugLoc();
unsigned LL, SC;
unsigned ZERO = Mips::ZERO;
unsigned BNE = Mips::BNE;
unsigned BEQ = Mips::BEQ;
unsigned SEOp =
I->getOpcode() == Mips::ATOMIC_CMP_SWAP_I8_POSTRA ? Mips::SEB : Mips::SEH;
if (STI->inMicroMipsMode()) {
LL = STI->hasMips32r6() ? Mips::LL_MMR6 : Mips::LL_MM;
SC = STI->hasMips32r6() ? Mips::SC_MMR6 : Mips::SC_MM;
BNE = STI->hasMips32r6() ? Mips::BNEC_MMR6 : Mips::BNE_MM;
BEQ = STI->hasMips32r6() ? Mips::BEQC_MMR6 : Mips::BEQ_MM;
} else {
LL = STI->hasMips32r6() ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
: (ArePtrs64bit ? Mips::LL64 : Mips::LL);
SC = STI->hasMips32r6() ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
: (ArePtrs64bit ? Mips::SC64 : Mips::SC);
}
unsigned Dest = I->getOperand(0).getReg();
unsigned Ptr = I->getOperand(1).getReg();
unsigned Mask = I->getOperand(2).getReg();
unsigned ShiftCmpVal = I->getOperand(3).getReg();
unsigned Mask2 = I->getOperand(4).getReg();
unsigned ShiftNewVal = I->getOperand(5).getReg();
unsigned ShiftAmnt = I->getOperand(6).getReg();
unsigned Scratch = I->getOperand(7).getReg();
unsigned Scratch2 = I->getOperand(8).getReg();
// insert new blocks after the current block
const BasicBlock *LLVM_BB = BB.getBasicBlock();
MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB);
MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB);
MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(LLVM_BB);
MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
MachineFunction::iterator It = ++BB.getIterator();
MF->insert(It, loop1MBB);
MF->insert(It, loop2MBB);
MF->insert(It, sinkMBB);
MF->insert(It, exitMBB);
// Transfer the remainder of BB and its successor edges to exitMBB.
exitMBB->splice(exitMBB->begin(), &BB,
std::next(MachineBasicBlock::iterator(I)), BB.end());
exitMBB->transferSuccessorsAndUpdatePHIs(&BB);
// thisMBB:
// ...
// fallthrough --> loop1MBB
BB.addSuccessor(loop1MBB, BranchProbability::getOne());
loop1MBB->addSuccessor(sinkMBB);
loop1MBB->addSuccessor(loop2MBB);
loop1MBB->normalizeSuccProbs();
loop2MBB->addSuccessor(loop1MBB);
loop2MBB->addSuccessor(sinkMBB);
loop2MBB->normalizeSuccProbs();
sinkMBB->addSuccessor(exitMBB, BranchProbability::getOne());
// loop1MBB:
// ll dest, 0(ptr)
// and Mask', dest, Mask
// bne Mask', ShiftCmpVal, exitMBB
BuildMI(loop1MBB, DL, TII->get(LL), Scratch).addReg(Ptr).addImm(0);
BuildMI(loop1MBB, DL, TII->get(Mips::AND), Scratch2)
.addReg(Scratch)
.addReg(Mask);
BuildMI(loop1MBB, DL, TII->get(BNE))
.addReg(Scratch2).addReg(ShiftCmpVal).addMBB(sinkMBB);
// loop2MBB:
// and dest, dest, mask2
// or dest, dest, ShiftNewVal
// sc dest, dest, 0(ptr)
// beq dest, $0, loop1MBB
BuildMI(loop2MBB, DL, TII->get(Mips::AND), Scratch)
.addReg(Scratch, RegState::Kill)
.addReg(Mask2);
BuildMI(loop2MBB, DL, TII->get(Mips::OR), Scratch)
.addReg(Scratch, RegState::Kill)
.addReg(ShiftNewVal);
BuildMI(loop2MBB, DL, TII->get(SC), Scratch)
.addReg(Scratch, RegState::Kill)
.addReg(Ptr)
.addImm(0);
BuildMI(loop2MBB, DL, TII->get(BEQ))
.addReg(Scratch, RegState::Kill)
.addReg(ZERO)
.addMBB(loop1MBB);
// sinkMBB:
// srl srlres, Mask', shiftamt
// sign_extend dest,srlres
BuildMI(sinkMBB, DL, TII->get(Mips::SRLV), Dest)
.addReg(Scratch2)
.addReg(ShiftAmnt);
if (STI->hasMips32r2()) {
BuildMI(sinkMBB, DL, TII->get(SEOp), Dest).addReg(Dest);
} else {
const unsigned ShiftImm =
I->getOpcode() == Mips::ATOMIC_CMP_SWAP_I16_POSTRA ? 16 : 24;
BuildMI(sinkMBB, DL, TII->get(Mips::SLL), Dest)
.addReg(Dest, RegState::Kill)
.addImm(ShiftImm);
BuildMI(sinkMBB, DL, TII->get(Mips::SRA), Dest)
.addReg(Dest, RegState::Kill)
.addImm(ShiftImm);
}
LivePhysRegs LiveRegs;
computeAndAddLiveIns(LiveRegs, *loop1MBB);
computeAndAddLiveIns(LiveRegs, *loop2MBB);
computeAndAddLiveIns(LiveRegs, *sinkMBB);
computeAndAddLiveIns(LiveRegs, *exitMBB);
NMBBI = BB.end();
I->eraseFromParent();
return true;
}
bool MipsExpandPseudo::expandAtomicCmpSwap(MachineBasicBlock &BB,
MachineBasicBlock::iterator I,
MachineBasicBlock::iterator &NMBBI) {
const unsigned Size =
I->getOpcode() == Mips::ATOMIC_CMP_SWAP_I32_POSTRA ? 4 : 8;
MachineFunction *MF = BB.getParent();
const bool ArePtrs64bit = STI->getABI().ArePtrs64bit();
DebugLoc DL = I->getDebugLoc();
unsigned LL, SC, ZERO, BNE, BEQ, MOVE;
if (Size == 4) {
if (STI->inMicroMipsMode()) {
LL = STI->hasMips32r6() ? Mips::LL_MMR6 : Mips::LL_MM;
SC = STI->hasMips32r6() ? Mips::SC_MMR6 : Mips::SC_MM;
BNE = STI->hasMips32r6() ? Mips::BNEC_MMR6 : Mips::BNE_MM;
BEQ = STI->hasMips32r6() ? Mips::BEQC_MMR6 : Mips::BEQ_MM;
} else {
LL = STI->hasMips32r6()
? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
: (ArePtrs64bit ? Mips::LL64 : Mips::LL);
SC = STI->hasMips32r6()
? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
: (ArePtrs64bit ? Mips::SC64 : Mips::SC);
BNE = Mips::BNE;
BEQ = Mips::BEQ;
}
ZERO = Mips::ZERO;
MOVE = Mips::OR;
} else {
LL = STI->hasMips64r6() ? Mips::LLD_R6 : Mips::LLD;
SC = STI->hasMips64r6() ? Mips::SCD_R6 : Mips::SCD;
ZERO = Mips::ZERO_64;
BNE = Mips::BNE64;
BEQ = Mips::BEQ64;
MOVE = Mips::OR64;
}
unsigned Dest = I->getOperand(0).getReg();
unsigned Ptr = I->getOperand(1).getReg();
unsigned OldVal = I->getOperand(2).getReg();
unsigned NewVal = I->getOperand(3).getReg();
unsigned Scratch = I->getOperand(4).getReg();
// insert new blocks after the current block
const BasicBlock *LLVM_BB = BB.getBasicBlock();
MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB);
MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB);
MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
MachineFunction::iterator It = ++BB.getIterator();
MF->insert(It, loop1MBB);
MF->insert(It, loop2MBB);
MF->insert(It, exitMBB);
// Transfer the remainder of BB and its successor edges to exitMBB.
exitMBB->splice(exitMBB->begin(), &BB,
std::next(MachineBasicBlock::iterator(I)), BB.end());
exitMBB->transferSuccessorsAndUpdatePHIs(&BB);
// thisMBB:
// ...
// fallthrough --> loop1MBB
BB.addSuccessor(loop1MBB, BranchProbability::getOne());
loop1MBB->addSuccessor(exitMBB);
loop1MBB->addSuccessor(loop2MBB);
loop1MBB->normalizeSuccProbs();
loop2MBB->addSuccessor(loop1MBB);
loop2MBB->addSuccessor(exitMBB);
loop2MBB->normalizeSuccProbs();
// loop1MBB:
// ll dest, 0(ptr)
// bne dest, oldval, exitMBB
BuildMI(loop1MBB, DL, TII->get(LL), Dest).addReg(Ptr).addImm(0);
BuildMI(loop1MBB, DL, TII->get(BNE))
.addReg(Dest, RegState::Kill).addReg(OldVal).addMBB(exitMBB);
// loop2MBB:
// move scratch, NewVal
// sc Scratch, Scratch, 0(ptr)
// beq Scratch, $0, loop1MBB
BuildMI(loop2MBB, DL, TII->get(MOVE), Scratch).addReg(NewVal).addReg(ZERO);
BuildMI(loop2MBB, DL, TII->get(SC), Scratch)
.addReg(Scratch).addReg(Ptr).addImm(0);
BuildMI(loop2MBB, DL, TII->get(BEQ))
.addReg(Scratch, RegState::Kill).addReg(ZERO).addMBB(loop1MBB);
LivePhysRegs LiveRegs;
computeAndAddLiveIns(LiveRegs, *loop1MBB);
computeAndAddLiveIns(LiveRegs, *loop2MBB);
computeAndAddLiveIns(LiveRegs, *exitMBB);
NMBBI = BB.end();
I->eraseFromParent();
return true;
}
bool MipsExpandPseudo::expandAtomicBinOpSubword(
MachineBasicBlock &BB, MachineBasicBlock::iterator I,
MachineBasicBlock::iterator &NMBBI) {
MachineFunction *MF = BB.getParent();
const bool ArePtrs64bit = STI->getABI().ArePtrs64bit();
DebugLoc DL = I->getDebugLoc();
unsigned LL, SC;
unsigned BEQ = Mips::BEQ;
unsigned SEOp = Mips::SEH;
if (STI->inMicroMipsMode()) {
LL = STI->hasMips32r6() ? Mips::LL_MMR6 : Mips::LL_MM;
SC = STI->hasMips32r6() ? Mips::SC_MMR6 : Mips::SC_MM;
BEQ = STI->hasMips32r6() ? Mips::BEQC_MMR6 : Mips::BEQ_MM;
} else {
LL = STI->hasMips32r6() ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
: (ArePtrs64bit ? Mips::LL64 : Mips::LL);
SC = STI->hasMips32r6() ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
: (ArePtrs64bit ? Mips::SC64 : Mips::SC);
}
bool IsSwap = false;
bool IsNand = false;
unsigned Opcode = 0;
switch (I->getOpcode()) {
case Mips::ATOMIC_LOAD_NAND_I8_POSTRA:
SEOp = Mips::SEB;
LLVM_FALLTHROUGH;
case Mips::ATOMIC_LOAD_NAND_I16_POSTRA:
IsNand = true;
break;
case Mips::ATOMIC_SWAP_I8_POSTRA:
SEOp = Mips::SEB;
LLVM_FALLTHROUGH;
case Mips::ATOMIC_SWAP_I16_POSTRA:
IsSwap = true;
break;
case Mips::ATOMIC_LOAD_ADD_I8_POSTRA:
SEOp = Mips::SEB;
LLVM_FALLTHROUGH;
case Mips::ATOMIC_LOAD_ADD_I16_POSTRA:
Opcode = Mips::ADDu;
break;
case Mips::ATOMIC_LOAD_SUB_I8_POSTRA:
SEOp = Mips::SEB;
LLVM_FALLTHROUGH;
case Mips::ATOMIC_LOAD_SUB_I16_POSTRA:
Opcode = Mips::SUBu;
break;
case Mips::ATOMIC_LOAD_AND_I8_POSTRA:
SEOp = Mips::SEB;
LLVM_FALLTHROUGH;
case Mips::ATOMIC_LOAD_AND_I16_POSTRA:
Opcode = Mips::AND;
break;
case Mips::ATOMIC_LOAD_OR_I8_POSTRA:
SEOp = Mips::SEB;
LLVM_FALLTHROUGH;
case Mips::ATOMIC_LOAD_OR_I16_POSTRA:
Opcode = Mips::OR;
break;
case Mips::ATOMIC_LOAD_XOR_I8_POSTRA:
SEOp = Mips::SEB;
LLVM_FALLTHROUGH;
case Mips::ATOMIC_LOAD_XOR_I16_POSTRA:
Opcode = Mips::XOR;
break;
default:
llvm_unreachable("Unknown subword atomic pseudo for expansion!");
}
unsigned Dest = I->getOperand(0).getReg();
unsigned Ptr = I->getOperand(1).getReg();
unsigned Incr = I->getOperand(2).getReg();
unsigned Mask = I->getOperand(3).getReg();
unsigned Mask2 = I->getOperand(4).getReg();
unsigned ShiftAmnt = I->getOperand(5).getReg();
unsigned OldVal = I->getOperand(6).getReg();
unsigned BinOpRes = I->getOperand(7).getReg();
unsigned StoreVal = I->getOperand(8).getReg();
const BasicBlock *LLVM_BB = BB.getBasicBlock();
MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(LLVM_BB);
MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
MachineFunction::iterator It = ++BB.getIterator();
MF->insert(It, loopMBB);
MF->insert(It, sinkMBB);
MF->insert(It, exitMBB);
exitMBB->splice(exitMBB->begin(), &BB, std::next(I), BB.end());
exitMBB->transferSuccessorsAndUpdatePHIs(&BB);
BB.addSuccessor(loopMBB, BranchProbability::getOne());
loopMBB->addSuccessor(sinkMBB);
loopMBB->addSuccessor(loopMBB);
loopMBB->normalizeSuccProbs();
BuildMI(loopMBB, DL, TII->get(LL), OldVal).addReg(Ptr).addImm(0);
if (IsNand) {
// and andres, oldval, incr2
// nor binopres, $0, andres
// and newval, binopres, mask
BuildMI(loopMBB, DL, TII->get(Mips::AND), BinOpRes)
.addReg(OldVal)
.addReg(Incr);
BuildMI(loopMBB, DL, TII->get(Mips::NOR), BinOpRes)
.addReg(Mips::ZERO)
.addReg(BinOpRes);
BuildMI(loopMBB, DL, TII->get(Mips::AND), BinOpRes)
.addReg(BinOpRes)
.addReg(Mask);
} else if (!IsSwap) {
// <binop> binopres, oldval, incr2
// and newval, binopres, mask
BuildMI(loopMBB, DL, TII->get(Opcode), BinOpRes)
.addReg(OldVal)
.addReg(Incr);
BuildMI(loopMBB, DL, TII->get(Mips::AND), BinOpRes)
.addReg(BinOpRes)
.addReg(Mask);
} else { // atomic.swap
// and newval, incr2, mask
BuildMI(loopMBB, DL, TII->get(Mips::AND), BinOpRes)
.addReg(Incr)
.addReg(Mask);
}
// and StoreVal, OlddVal, Mask2
// or StoreVal, StoreVal, BinOpRes
// StoreVal<tied1> = sc StoreVal, 0(Ptr)
// beq StoreVal, zero, loopMBB
BuildMI(loopMBB, DL, TII->get(Mips::AND), StoreVal)
.addReg(OldVal).addReg(Mask2);
BuildMI(loopMBB, DL, TII->get(Mips::OR), StoreVal)
.addReg(StoreVal).addReg(BinOpRes);
BuildMI(loopMBB, DL, TII->get(SC), StoreVal)
.addReg(StoreVal).addReg(Ptr).addImm(0);
BuildMI(loopMBB, DL, TII->get(BEQ))
.addReg(StoreVal).addReg(Mips::ZERO).addMBB(loopMBB);
// sinkMBB:
// and maskedoldval1,oldval,mask
// srl srlres,maskedoldval1,shiftamt
// sign_extend dest,srlres
sinkMBB->addSuccessor(exitMBB, BranchProbability::getOne());
BuildMI(sinkMBB, DL, TII->get(Mips::AND), Dest)
.addReg(OldVal).addReg(Mask);
BuildMI(sinkMBB, DL, TII->get(Mips::SRLV), Dest)
.addReg(Dest).addReg(ShiftAmnt);
if (STI->hasMips32r2()) {
BuildMI(sinkMBB, DL, TII->get(SEOp), Dest).addReg(Dest);
} else {
const unsigned ShiftImm = SEOp == Mips::SEH ? 16 : 24;
BuildMI(sinkMBB, DL, TII->get(Mips::SLL), Dest)
.addReg(Dest, RegState::Kill)
.addImm(ShiftImm);
BuildMI(sinkMBB, DL, TII->get(Mips::SRA), Dest)
.addReg(Dest, RegState::Kill)
.addImm(ShiftImm);
}
LivePhysRegs LiveRegs;
computeAndAddLiveIns(LiveRegs, *loopMBB);
computeAndAddLiveIns(LiveRegs, *sinkMBB);
computeAndAddLiveIns(LiveRegs, *exitMBB);
NMBBI = BB.end();
I->eraseFromParent();
return true;
}
bool MipsExpandPseudo::expandAtomicBinOp(MachineBasicBlock &BB,
MachineBasicBlock::iterator I,
MachineBasicBlock::iterator &NMBBI,
unsigned Size) {
MachineFunction *MF = BB.getParent();
const bool ArePtrs64bit = STI->getABI().ArePtrs64bit();
DebugLoc DL = I->getDebugLoc();
unsigned LL, SC, ZERO, BEQ;
if (Size == 4) {
if (STI->inMicroMipsMode()) {
LL = STI->hasMips32r6() ? Mips::LL_MMR6 : Mips::LL_MM;
SC = STI->hasMips32r6() ? Mips::SC_MMR6 : Mips::SC_MM;
BEQ = STI->hasMips32r6() ? Mips::BEQC_MMR6 : Mips::BEQ_MM;
} else {
LL = STI->hasMips32r6()
? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
: (ArePtrs64bit ? Mips::LL64 : Mips::LL);
SC = STI->hasMips32r6()
? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
: (ArePtrs64bit ? Mips::SC64 : Mips::SC);
BEQ = Mips::BEQ;
}
ZERO = Mips::ZERO;
} else {
LL = STI->hasMips64r6() ? Mips::LLD_R6 : Mips::LLD;
SC = STI->hasMips64r6() ? Mips::SCD_R6 : Mips::SCD;
ZERO = Mips::ZERO_64;
BEQ = Mips::BEQ64;
}
unsigned OldVal = I->getOperand(0).getReg();
unsigned Ptr = I->getOperand(1).getReg();
unsigned Incr = I->getOperand(2).getReg();
unsigned Scratch = I->getOperand(3).getReg();
unsigned Opcode = 0;
unsigned OR = 0;
unsigned AND = 0;
unsigned NOR = 0;
bool IsNand = false;
switch (I->getOpcode()) {
case Mips::ATOMIC_LOAD_ADD_I32_POSTRA:
Opcode = Mips::ADDu;
break;
case Mips::ATOMIC_LOAD_SUB_I32_POSTRA:
Opcode = Mips::SUBu;
break;
case Mips::ATOMIC_LOAD_AND_I32_POSTRA:
Opcode = Mips::AND;
break;
case Mips::ATOMIC_LOAD_OR_I32_POSTRA:
Opcode = Mips::OR;
break;
case Mips::ATOMIC_LOAD_XOR_I32_POSTRA:
Opcode = Mips::XOR;
break;
case Mips::ATOMIC_LOAD_NAND_I32_POSTRA:
IsNand = true;
AND = Mips::AND;
NOR = Mips::NOR;
break;
case Mips::ATOMIC_SWAP_I32_POSTRA:
OR = Mips::OR;
break;
case Mips::ATOMIC_LOAD_ADD_I64_POSTRA:
Opcode = Mips::DADDu;
break;
case Mips::ATOMIC_LOAD_SUB_I64_POSTRA:
Opcode = Mips::DSUBu;
break;
case Mips::ATOMIC_LOAD_AND_I64_POSTRA:
Opcode = Mips::AND64;
break;
case Mips::ATOMIC_LOAD_OR_I64_POSTRA:
Opcode = Mips::OR64;
break;
case Mips::ATOMIC_LOAD_XOR_I64_POSTRA:
Opcode = Mips::XOR64;
break;
case Mips::ATOMIC_LOAD_NAND_I64_POSTRA:
IsNand = true;
AND = Mips::AND64;
NOR = Mips::NOR64;
break;
case Mips::ATOMIC_SWAP_I64_POSTRA:
OR = Mips::OR64;
break;
default:
llvm_unreachable("Unknown pseudo atomic!");
}
const BasicBlock *LLVM_BB = BB.getBasicBlock();
MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
MachineFunction::iterator It = ++BB.getIterator();
MF->insert(It, loopMBB);
MF->insert(It, exitMBB);
exitMBB->splice(exitMBB->begin(), &BB, std::next(I), BB.end());
exitMBB->transferSuccessorsAndUpdatePHIs(&BB);
BB.addSuccessor(loopMBB, BranchProbability::getOne());
loopMBB->addSuccessor(exitMBB);
loopMBB->addSuccessor(loopMBB);
loopMBB->normalizeSuccProbs();
BuildMI(loopMBB, DL, TII->get(LL), OldVal).addReg(Ptr).addImm(0);
assert((OldVal != Ptr) && "Clobbered the wrong ptr reg!");
assert((OldVal != Incr) && "Clobbered the wrong reg!");
if (Opcode) {
BuildMI(loopMBB, DL, TII->get(Opcode), Scratch).addReg(OldVal).addReg(Incr);
} else if (IsNand) {
assert(AND && NOR &&
"Unknown nand instruction for atomic pseudo expansion");
BuildMI(loopMBB, DL, TII->get(AND), Scratch).addReg(OldVal).addReg(Incr);
BuildMI(loopMBB, DL, TII->get(NOR), Scratch).addReg(ZERO).addReg(Scratch);
} else {
assert(OR && "Unknown instruction for atomic pseudo expansion!");
BuildMI(loopMBB, DL, TII->get(OR), Scratch).addReg(Incr).addReg(ZERO);
}
BuildMI(loopMBB, DL, TII->get(SC), Scratch).addReg(Scratch).addReg(Ptr).addImm(0);
BuildMI(loopMBB, DL, TII->get(BEQ)).addReg(Scratch).addReg(ZERO).addMBB(loopMBB);
NMBBI = BB.end();
I->eraseFromParent();
LivePhysRegs LiveRegs;
computeAndAddLiveIns(LiveRegs, *loopMBB);
computeAndAddLiveIns(LiveRegs, *exitMBB);
return true;
}
bool MipsExpandPseudo::expandMI(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
MachineBasicBlock::iterator &NMBB) {
bool Modified = false;
switch (MBBI->getOpcode()) {
case Mips::ATOMIC_CMP_SWAP_I32_POSTRA:
case Mips::ATOMIC_CMP_SWAP_I64_POSTRA:
return expandAtomicCmpSwap(MBB, MBBI, NMBB);
case Mips::ATOMIC_CMP_SWAP_I8_POSTRA:
case Mips::ATOMIC_CMP_SWAP_I16_POSTRA:
return expandAtomicCmpSwapSubword(MBB, MBBI, NMBB);
case Mips::ATOMIC_SWAP_I8_POSTRA:
case Mips::ATOMIC_SWAP_I16_POSTRA:
case Mips::ATOMIC_LOAD_NAND_I8_POSTRA:
case Mips::ATOMIC_LOAD_NAND_I16_POSTRA:
case Mips::ATOMIC_LOAD_ADD_I8_POSTRA:
case Mips::ATOMIC_LOAD_ADD_I16_POSTRA:
case Mips::ATOMIC_LOAD_SUB_I8_POSTRA:
case Mips::ATOMIC_LOAD_SUB_I16_POSTRA:
case Mips::ATOMIC_LOAD_AND_I8_POSTRA:
case Mips::ATOMIC_LOAD_AND_I16_POSTRA:
case Mips::ATOMIC_LOAD_OR_I8_POSTRA:
case Mips::ATOMIC_LOAD_OR_I16_POSTRA:
case Mips::ATOMIC_LOAD_XOR_I8_POSTRA:
case Mips::ATOMIC_LOAD_XOR_I16_POSTRA:
return expandAtomicBinOpSubword(MBB, MBBI, NMBB);
case Mips::ATOMIC_LOAD_ADD_I32_POSTRA:
case Mips::ATOMIC_LOAD_SUB_I32_POSTRA:
case Mips::ATOMIC_LOAD_AND_I32_POSTRA:
case Mips::ATOMIC_LOAD_OR_I32_POSTRA:
case Mips::ATOMIC_LOAD_XOR_I32_POSTRA:
case Mips::ATOMIC_LOAD_NAND_I32_POSTRA:
case Mips::ATOMIC_SWAP_I32_POSTRA:
return expandAtomicBinOp(MBB, MBBI, NMBB, 4);
case Mips::ATOMIC_LOAD_ADD_I64_POSTRA:
case Mips::ATOMIC_LOAD_SUB_I64_POSTRA:
case Mips::ATOMIC_LOAD_AND_I64_POSTRA:
case Mips::ATOMIC_LOAD_OR_I64_POSTRA:
case Mips::ATOMIC_LOAD_XOR_I64_POSTRA:
case Mips::ATOMIC_LOAD_NAND_I64_POSTRA:
case Mips::ATOMIC_SWAP_I64_POSTRA:
return expandAtomicBinOp(MBB, MBBI, NMBB, 8);
default:
return Modified;
}
}
bool MipsExpandPseudo::expandMBB(MachineBasicBlock &MBB) {
bool Modified = false;
MachineBasicBlock::iterator MBBI = MBB.begin(), E = MBB.end();
while (MBBI != E) {
MachineBasicBlock::iterator NMBBI = std::next(MBBI);
Modified |= expandMI(MBB, MBBI, NMBBI);
MBBI = NMBBI;
}
return Modified;
}
bool MipsExpandPseudo::runOnMachineFunction(MachineFunction &MF) {
STI = &static_cast<const MipsSubtarget &>(MF.getSubtarget());
TII = STI->getInstrInfo();
bool Modified = false;
for (MachineFunction::iterator MFI = MF.begin(), E = MF.end(); MFI != E;
++MFI)
Modified |= expandMBB(*MFI);
if (Modified)
MF.RenumberBlocks();
return Modified;
}
/// createMipsExpandPseudoPass - returns an instance of the pseudo instruction
/// expansion pass.
FunctionPass *llvm::createMipsExpandPseudoPass() {
return new MipsExpandPseudo();
}