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Unified Diff: src/IceTargetLoweringARM32.cpp

Issue 1409863006: Subzero. ARM32. Refactors atomic intrinsics lowering. (Closed) Base URL: https://chromium.googlesource.com/native_client/pnacl-subzero.git@master
Patch Set: Created 4 years, 10 months ago
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Index: src/IceTargetLoweringARM32.cpp
diff --git a/src/IceTargetLoweringARM32.cpp b/src/IceTargetLoweringARM32.cpp
index 0b12bc6a8a60d4c776dfd2bd4e92d2445a83189f..e042b1958e169707f096f338bfe3ff83eaf083c4 100644
--- a/src/IceTargetLoweringARM32.cpp
+++ b/src/IceTargetLoweringARM32.cpp
@@ -385,7 +385,8 @@ void copyRegAllocFromInfWeightVariable64On32(const VarList &Vars) {
// This is not the variable we are looking for.
continue;
}
- assert(Var64->hasReg() || !Var64->mustHaveReg());
+ // only allow infinite-weight i64 temporaries to be register allocated.
+ assert(!Var64->hasReg() || Var64->mustHaveReg());
if (!Var64->hasReg()) {
continue;
}
@@ -3408,14 +3409,14 @@ void TargetARM32::lowerAssign(const InstAssign *Instr) {
if (Dest->getType() == IceType_i64) {
Src0 = legalizeUndef(Src0);
- Variable *T_Lo = makeReg(IceType_i32);
auto *DestLo = llvm::cast<Variable>(loOperand(Dest));
Jim Stichnoth 2016/02/17 03:50:17 Just curious - why these changes?
John 2016/02/17 13:01:38 I was fiddling around trying to avoid some unneces
+ Variable *T_Lo = makeReg(IceType_i32);
Operand *Src0Lo = legalize(loOperand(Src0), Legal_Reg | Legal_Flex);
_mov(T_Lo, Src0Lo);
_mov(DestLo, T_Lo);
- Variable *T_Hi = makeReg(IceType_i32);
auto *DestHi = llvm::cast<Variable>(hiOperand(Dest));
+ Variable *T_Hi = makeReg(IceType_i32);
Operand *Src0Hi = legalize(hiOperand(Src0), Legal_Reg | Legal_Flex);
_mov(T_Hi, Src0Hi);
_mov(DestHi, T_Hi);
@@ -4401,10 +4402,16 @@ TargetARM32::lowerInt8AndInt16IcmpCond(InstIcmp::ICond Condition, Operand *Src0,
}
TargetARM32::CondWhenTrue TargetARM32::lowerIcmpCond(const InstIcmp *Instr) {
- Operand *Src0 = legalizeUndef(Instr->getSrc(0));
- Operand *Src1 = legalizeUndef(Instr->getSrc(1));
+ return lowerIcmpCond(Instr->getCondition(), Instr->getSrc(0),
+ Instr->getSrc(1));
+}
+
+TargetARM32::CondWhenTrue TargetARM32::lowerIcmpCond(InstIcmp::ICond Condition,
+ Operand *Src0,
+ Operand *Src1) {
+ Src0 = legalizeUndef(Src0);
+ Src1 = legalizeUndef(Src1);
- const InstIcmp::ICond Condition = Instr->getCondition();
// a=icmp cond b, c ==>
// GCC does:
// <u/s>xtb tb, b
@@ -4504,162 +4511,156 @@ inline uint64_t getConstantMemoryOrder(Operand *Opnd) {
}
} // end of anonymous namespace
-void TargetARM32::lowerAtomicRMW(Variable *Dest, uint32_t Operation,
- Operand *Ptr, Operand *Val) {
- // retry:
- // ldrex contents, [addr]
- // op tmp, contents, operand
- // strex success, tmp, [addr]
- // jne retry
- // fake-use(addr, operand) @ prevents undesirable clobbering.
- // mov dest, contents
- assert(Dest != nullptr);
- Type DestTy = Dest->getType();
- (void)Ptr;
- (void)Val;
-
- OperandARM32Mem *Mem;
- Variable *PtrContentsReg;
- Variable *PtrContentsHiReg;
- Variable *PtrContentsLoReg;
- Variable *Value = Func->makeVariable(DestTy);
- Variable *ValueReg;
- Variable *ValueHiReg;
- Variable *ValueLoReg;
- Variable *Success = makeReg(IceType_i32);
- Variable *TmpReg;
- Variable *TmpHiReg;
- Variable *TmpLoReg;
- Operand *_0 = Ctx->getConstantZero(IceType_i32);
- auto *Retry = InstARM32Label::create(Func, this);
-
- if (DestTy == IceType_i64) {
- Variable64On32 *PtrContentsReg64 = makeI64RegPair();
- PtrContentsHiReg = PtrContentsReg64->getHi();
- PtrContentsLoReg = PtrContentsReg64->getLo();
- PtrContentsReg = PtrContentsReg64;
-
- llvm::cast<Variable64On32>(Value)->initHiLo(Func);
- Variable64On32 *ValueReg64 = makeI64RegPair();
- ValueHiReg = ValueReg64->getHi();
- ValueLoReg = ValueReg64->getLo();
- ValueReg = ValueReg64;
-
- Variable64On32 *TmpReg64 = makeI64RegPair();
- TmpHiReg = TmpReg64->getHi();
- TmpLoReg = TmpReg64->getLo();
- TmpReg = TmpReg64;
- } else {
- PtrContentsReg = makeReg(DestTy);
- PtrContentsHiReg = nullptr;
- PtrContentsLoReg = PtrContentsReg;
-
- ValueReg = makeReg(DestTy);
- ValueHiReg = nullptr;
- ValueLoReg = ValueReg;
-
- TmpReg = makeReg(DestTy);
- TmpHiReg = nullptr;
- TmpLoReg = TmpReg;
- }
-
- if (DestTy == IceType_i64) {
- Context.insert<InstFakeDef>(Value);
+void TargetARM32::lowerLoadLinkedStoreExclusive(
+ Type Ty, Operand *Addr, std::function<Variable *(Variable *)> Operation,
+ CondARM32::Cond Cond) {
+
+ auto *Retry = Context.insert<InstARM32Label>(this);
+ { // scoping for loop highlighting.
+ Variable *Tmp = (Ty == IceType_i64) ? makeI64RegPair() : makeReg(Ty);
+ auto *Success = makeReg(IceType_i32);
+ auto *_0 = Ctx->getConstantZero(IceType_i32);
+
+ Context.insert<InstFakeDef>(Tmp);
+ Context.insert<InstFakeUse>(Tmp);
+ Variable *AddrR = legalizeToReg(Addr);
+ _ldrex(Tmp, formMemoryOperand(AddrR, Ty))->setDestRedefined();
+ auto *StoreValue = Operation(Tmp);
+ assert(StoreValue->mustHaveReg());
+ _strex(Success, StoreValue, formMemoryOperand(AddrR, Ty), Cond);
+ _cmp(Success, _0, Cond);
}
- lowerAssign(InstAssign::create(Func, Value, Val));
-
- Variable *PtrVar = Func->makeVariable(IceType_i32);
- lowerAssign(InstAssign::create(Func, PtrVar, Ptr));
-
- _dmb();
- Context.insert(Retry);
- Mem = formMemoryOperand(PtrVar, DestTy);
- if (DestTy == IceType_i64) {
- Context.insert<InstFakeDef>(ValueReg, Value);
- }
- lowerAssign(InstAssign::create(Func, ValueReg, Value));
- if (DestTy == IceType_i8 || DestTy == IceType_i16) {
- _uxt(ValueReg, ValueReg);
- }
- _ldrex(PtrContentsReg, Mem);
+ _br(Retry, CondARM32::NE);
+}
- if (DestTy == IceType_i64) {
- Context.insert<InstFakeDef>(TmpReg, ValueReg);
- }
+namespace {
+InstArithmetic *createArithInst(Cfg *Func, uint32_t Operation, Variable *Dest,
+ Variable *Src0, Operand *Src1) {
+ InstArithmetic::OpKind Oper;
switch (Operation) {
default:
- Func->setError("Unknown AtomicRMW operation");
- return;
+ llvm::report_fatal_error("Unknown AtomicRMW operation");
+ case Intrinsics::AtomicExchange:
+ llvm::report_fatal_error("Can't handle Atomic xchg operation");
case Intrinsics::AtomicAdd:
- if (DestTy == IceType_i64) {
- _adds(TmpLoReg, PtrContentsLoReg, ValueLoReg);
- _adc(TmpHiReg, PtrContentsHiReg, ValueHiReg);
- } else {
- _add(TmpLoReg, PtrContentsLoReg, ValueLoReg);
- }
+ Oper = InstArithmetic::Add;
+ break;
+ case Intrinsics::AtomicAnd:
+ Oper = InstArithmetic::And;
break;
case Intrinsics::AtomicSub:
- if (DestTy == IceType_i64) {
- _subs(TmpLoReg, PtrContentsLoReg, ValueLoReg);
- _sbc(TmpHiReg, PtrContentsHiReg, ValueHiReg);
- } else {
- _sub(TmpLoReg, PtrContentsLoReg, ValueLoReg);
- }
+ Oper = InstArithmetic::Sub;
break;
case Intrinsics::AtomicOr:
- _orr(TmpLoReg, PtrContentsLoReg, ValueLoReg);
- if (DestTy == IceType_i64) {
- _orr(TmpHiReg, PtrContentsHiReg, ValueHiReg);
- }
- break;
- case Intrinsics::AtomicAnd:
- _and(TmpLoReg, PtrContentsLoReg, ValueLoReg);
- if (DestTy == IceType_i64) {
- _and(TmpHiReg, PtrContentsHiReg, ValueHiReg);
- }
+ Oper = InstArithmetic::Or;
break;
case Intrinsics::AtomicXor:
- _eor(TmpLoReg, PtrContentsLoReg, ValueLoReg);
- if (DestTy == IceType_i64) {
- _eor(TmpHiReg, PtrContentsHiReg, ValueHiReg);
- }
- break;
- case Intrinsics::AtomicExchange:
- _mov(TmpLoReg, ValueLoReg);
- if (DestTy == IceType_i64) {
- _mov(TmpHiReg, ValueHiReg);
- }
+ Oper = InstArithmetic::Xor;
break;
}
- _strex(Success, TmpReg, Mem);
- _cmp(Success, _0);
- _br(Retry, CondARM32::NE);
+ return InstArithmetic::create(Func, Oper, Dest, Src0, Src1);
+}
+} // end of anonymous namespace
+
+void TargetARM32::lowerAtomicRMW(Variable *Dest, uint32_t Operation,
+ Operand *Addr, Operand *Val) {
+ // retry:
+ // ldrex tmp, [addr]
+ // mov contents, tmp
+ // op result, contents, Val
+ // strex success, result, [addr]
+ // cmp success, 0
+ // jne retry
+ // fake-use(addr, operand) @ prevents undesirable clobbering.
+ // mov dest, contents
+ auto DestTy = Dest->getType();
+
+ if (DestTy == IceType_i64) {
+ lowerInt64AtomicRMW(Dest, Operation, Addr, Val);
+ return;
+ }
- // The following fake-uses ensure that Subzero will not clobber them in the
- // load-linked/store-conditional loop above. We might have to spill them, but
- // spilling is preferable over incorrect behavior.
- Context.insert<InstFakeUse>(PtrVar);
- if (auto *Value64 = llvm::dyn_cast<Variable64On32>(Value)) {
- Context.insert<InstFakeUse>(Value64->getHi());
- Context.insert<InstFakeUse>(Value64->getLo());
+ Operand *ValRF = nullptr;
+ if (llvm::isa<ConstantInteger32>(Val)) {
+ ValRF = Val;
} else {
- Context.insert<InstFakeUse>(Value);
+ ValRF = legalizeToReg(Val);
}
+ auto *ContentsR = makeReg(DestTy);
+ auto *ResultR = makeReg(DestTy);
+
_dmb();
- if (DestTy == IceType_i8 || DestTy == IceType_i16) {
- _uxt(PtrContentsReg, PtrContentsReg);
+ lowerLoadLinkedStoreExclusive(
+ DestTy, Addr,
+ [this, Operation, ResultR, ContentsR, ValRF](Variable *Tmp) {
+ lowerAssign(InstAssign::create(Func, ContentsR, Tmp));
+ if (Operation == Intrinsics::AtomicExchange) {
+ lowerAssign(InstAssign::create(Func, ResultR, ValRF));
+ } else {
+ lowerArithmetic(
+ createArithInst(Func, Operation, ResultR, ContentsR, ValRF));
+ }
+ return ResultR;
+ });
+ _dmb();
+ if (auto *ValR = llvm::dyn_cast<Variable>(ValRF)) {
+ Context.insert<InstFakeUse>(ValR);
}
+ // Can't dce ContentsR.
+ Context.insert<InstFakeUse>(ContentsR);
+ lowerAssign(InstAssign::create(Func, Dest, ContentsR));
+}
- if (DestTy == IceType_i64) {
- Context.insert<InstFakeUse>(PtrContentsReg);
- }
- lowerAssign(InstAssign::create(Func, Dest, PtrContentsReg));
- if (auto *Dest64 = llvm::dyn_cast<Variable64On32>(Dest)) {
- Context.insert<InstFakeUse>(Dest64->getLo());
- Context.insert<InstFakeUse>(Dest64->getHi());
+void TargetARM32::lowerInt64AtomicRMW(Variable *Dest, uint32_t Operation,
+ Operand *Addr, Operand *Val) {
+ assert(Dest->getType() == IceType_i64);
+
+ auto *ResultR = makeI64RegPair();
+
+ Context.insert<InstFakeDef>(ResultR);
+
+ Operand *ValRF = nullptr;
+ if (llvm::dyn_cast<ConstantInteger64>(Val)) {
+ ValRF = Val;
} else {
- Context.insert<InstFakeUse>(Dest);
+ auto *ValR64 = llvm::cast<Variable64On32>(Func->makeVariable(IceType_i64));
+ ValR64->initHiLo(Func);
+ ValR64->setMustNotHaveReg();
+ ValR64->getLo()->setMustHaveReg();
+ ValR64->getHi()->setMustHaveReg();
+ lowerAssign(InstAssign::create(Func, ValR64, Val));
+ ValRF = ValR64;
+ }
+
+ auto *ContentsR = llvm::cast<Variable64On32>(Func->makeVariable(IceType_i64));
+ ContentsR->initHiLo(Func);
+ ContentsR->setMustNotHaveReg();
+ ContentsR->getLo()->setMustHaveReg();
+ ContentsR->getHi()->setMustHaveReg();
+
+ _dmb();
+ lowerLoadLinkedStoreExclusive(
+ IceType_i64, Addr,
+ [this, Operation, ResultR, ContentsR, ValRF](Variable *Tmp) {
+ lowerAssign(InstAssign::create(Func, ContentsR, Tmp));
+ Context.insert<InstFakeUse>(Tmp);
+ if (Operation == Intrinsics::AtomicExchange) {
+ lowerAssign(InstAssign::create(Func, ResultR, ValRF));
+ } else {
+ lowerArithmetic(
+ createArithInst(Func, Operation, ResultR, ContentsR, ValRF));
+ }
+ Context.insert<InstFakeUse>(ResultR->getHi());
+ Context.insert<InstFakeDef>(ResultR, ResultR->getLo())
+ ->setDestRedefined();
+ return ResultR;
+ });
+ _dmb();
+ if (auto *ValR64 = llvm::dyn_cast<Variable64On32>(ValRF)) {
+ Context.insert<InstFakeUse>(ValR64->getLo());
+ Context.insert<InstFakeUse>(ValR64->getHi());
}
+ lowerAssign(InstAssign::create(Func, Dest, ContentsR));
}
void TargetARM32::postambleCtpop64(const InstCall *Instr) {
@@ -4733,10 +4734,9 @@ void TargetARM32::lowerIntrinsicCall(const InstIntrinsicCall *Instr) {
}
_dmb();
lowerAssign(InstAssign::create(Func, Dest, T));
- // Make sure the atomic load isn't elided when unused, by adding a FakeUse.
- // Since lowerLoad may fuse the load w/ an arithmetic instruction, insert
- // the FakeUse on the last-inserted instruction's dest.
- Context.insert<InstFakeUse>(Context.getLastInserted()->getDest());
+ // Adding a fake-use T to ensure the atomic load is not removed if Dest is
+ // unused.
+ Context.insert<InstFakeUse>(T);
return;
}
case Intrinsics::AtomicStore: {
@@ -4747,105 +4747,48 @@ void TargetARM32::lowerIntrinsicCall(const InstIntrinsicCall *Instr) {
Func->setError("Unexpected memory ordering for AtomicStore");
return;
}
- Operand *Value = Instr->getArg(0);
- Type ValueTy = Value->getType();
- assert(isScalarIntegerType(ValueTy));
- Operand *Addr = Instr->getArg(1);
-
- if (ValueTy == IceType_i64) {
- // Atomic 64-bit stores require a load-locked/store-conditional loop using
- // ldrexd, and strexd. The lowered code is:
- //
- // retry:
- // ldrexd t.lo, t.hi, [addr]
- // strexd success, value.lo, value.hi, [addr]
- // cmp success, #0
- // bne retry
- // fake-use(addr, value.lo, value.hi)
- //
- // The fake-use is needed to prevent those variables from being clobbered
- // in the loop (which will happen under register pressure.)
- Variable64On32 *Tmp = makeI64RegPair();
- Variable64On32 *ValueVar =
- llvm::cast<Variable64On32>(Func->makeVariable(IceType_i64));
- Variable *AddrVar = makeReg(IceType_i32);
- Variable *Success = makeReg(IceType_i32);
- OperandARM32Mem *Mem;
- Operand *_0 = Ctx->getConstantZero(IceType_i32);
- auto *Retry = InstARM32Label::create(Func, this);
- Variable64On32 *NewReg = makeI64RegPair();
- ValueVar->initHiLo(Func);
- ValueVar->mustNotHaveReg();
+ auto *Value = Instr->getArg(0);
+ if (Value->getType() == IceType_i64) {
+ auto *ValueR = makeI64RegPair();
+ Context.insert<InstFakeDef>(ValueR);
+ lowerAssign(InstAssign::create(Func, ValueR, Value));
_dmb();
- lowerAssign(InstAssign::create(Func, ValueVar, Value));
- lowerAssign(InstAssign::create(Func, AddrVar, Addr));
-
- Context.insert(Retry);
- Context.insert<InstFakeDef>(NewReg);
- lowerAssign(InstAssign::create(Func, NewReg, ValueVar));
- Mem = formMemoryOperand(AddrVar, IceType_i64);
- _ldrex(Tmp, Mem);
- // This fake-use both prevents the ldrex from being dead-code eliminated,
- // while also keeping liveness happy about all defs being used.
- Context.insert<InstFakeUse>(Context.getLastInserted()->getDest());
- _strex(Success, NewReg, Mem);
- _cmp(Success, _0);
- _br(Retry, CondARM32::NE);
-
- Context.insert<InstFakeUse>(ValueVar->getLo());
- Context.insert<InstFakeUse>(ValueVar->getHi());
- Context.insert<InstFakeUse>(AddrVar);
+ lowerLoadLinkedStoreExclusive(
+ IceType_i64, Instr->getArg(1), [this, ValueR](Variable *Tmp) {
+ // The following fake-use prevents the ldrex instruction from being
+ // dead code eliminated.
+ Context.insert<InstFakeUse>(llvm::cast<Variable>(loOperand(Tmp)));
+ Context.insert<InstFakeUse>(llvm::cast<Variable>(hiOperand(Tmp)));
+ Context.insert<InstFakeUse>(Tmp);
+ return ValueR;
+ });
+ Context.insert<InstFakeUse>(ValueR);
_dmb();
return;
}
+
+ auto *ValueR = legalizeToReg(Instr->getArg(0));
+ Type ValueTy = ValueR->getType();
Jim Stichnoth 2016/02/17 03:50:17 Surprised that "auto" wasn't used here.
John 2016/02/17 13:01:39 not to mention the lack of constness... :) Done.
+ assert(isScalarIntegerType(ValueTy));
+ auto *Addr = legalizeToReg(Instr->getArg(1));
+
// non-64-bit stores are atomically as long as the address is aligned. This
// is PNaCl, so addresses are aligned.
- Variable *T = makeReg(ValueTy);
-
_dmb();
- lowerAssign(InstAssign::create(Func, T, Value));
- _str(T, formMemoryOperand(Addr, ValueTy));
+ _str(ValueR, formMemoryOperand(Addr, ValueTy));
_dmb();
return;
}
case Intrinsics::AtomicCmpxchg: {
- // The initial lowering for cmpxchg was:
- //
// retry:
// ldrex tmp, [addr]
// cmp tmp, expected
// mov expected, tmp
- // jne retry
- // strex success, new, [addr]
- // cmp success, #0
- // bne retry
- // mov dest, expected
- //
- // Besides requiring two branches, that lowering could also potentially
- // write to memory (in mov expected, tmp) unless we were OK with increasing
- // the register pressure and requiring expected to be an infinite-weight
- // variable (spoiler alert: that was a problem for i64 cmpxchg.) Through
- // careful rewritting, and thanks to predication, we now implement the
- // lowering as:
- //
- // retry:
- // ldrex tmp, [addr]
- // cmp tmp, expected
// strexeq success, new, [addr]
- // movne expected, tmp
// cmpeq success, #0
// bne retry
// mov dest, expected
- //
- // Predication lets us move the strex ahead of the mov expected, tmp, which
- // allows tmp to be a non-infinite weight temporary. We wanted to avoid
- // writing to memory between ldrex and strex because, even though most times
- // that would cause no issues, if any interleaving memory write aliased
- // [addr] than we would have undefined behavior. Undefined behavior isn't
- // cool, so we try to avoid it. See the "Synchronization and semaphores"
- // section of the "ARM Architecture Reference Manual."
-
assert(isScalarIntegerType(DestTy));
// We require the memory address to be naturally aligned. Given that is the
// case, then normal loads are atomic.
@@ -4856,98 +4799,63 @@ void TargetARM32::lowerIntrinsicCall(const InstIntrinsicCall *Instr) {
return;
}
- OperandARM32Mem *Mem;
- Variable *TmpReg;
- Variable *Expected, *ExpectedReg;
- Variable *New, *NewReg;
- Variable *Success = makeReg(IceType_i32);
- Operand *_0 = Ctx->getConstantZero(IceType_i32);
- auto *Retry = InstARM32Label::create(Func, this);
-
if (DestTy == IceType_i64) {
- Variable64On32 *TmpReg64 = makeI64RegPair();
- Variable64On32 *New64 =
- llvm::cast<Variable64On32>(Func->makeVariable(IceType_i64));
- Variable64On32 *NewReg64 = makeI64RegPair();
- Variable64On32 *Expected64 =
- llvm::cast<Variable64On32>(Func->makeVariable(IceType_i64));
- Variable64On32 *ExpectedReg64 = makeI64RegPair();
-
- New64->initHiLo(Func);
- New64->mustNotHaveReg();
- Expected64->initHiLo(Func);
- Expected64->mustNotHaveReg();
-
- TmpReg = TmpReg64;
- New = New64;
- NewReg = NewReg64;
- Expected = Expected64;
- ExpectedReg = ExpectedReg64;
- } else {
- TmpReg = makeReg(DestTy);
- New = Func->makeVariable(DestTy);
- NewReg = makeReg(DestTy);
- Expected = Func->makeVariable(DestTy);
- ExpectedReg = makeReg(DestTy);
- }
+ auto *New = makeI64RegPair();
+ Context.insert<InstFakeDef>(New);
+ lowerAssign(InstAssign::create(Func, New, Instr->getArg(2)));
- Mem = formMemoryOperand(Instr->getArg(0), DestTy);
- if (DestTy == IceType_i64) {
+ auto *Expected = makeI64RegPair();
Context.insert<InstFakeDef>(Expected);
- }
- lowerAssign(InstAssign::create(Func, Expected, Instr->getArg(1)));
- if (DestTy == IceType_i64) {
- Context.insert<InstFakeDef>(New);
- }
- lowerAssign(InstAssign::create(Func, New, Instr->getArg(2)));
- _dmb();
+ lowerAssign(InstAssign::create(Func, Expected, Instr->getArg(1)));
- Context.insert(Retry);
- if (DestTy == IceType_i64) {
- Context.insert<InstFakeDef>(ExpectedReg, Expected);
- }
- lowerAssign(InstAssign::create(Func, ExpectedReg, Expected));
- if (DestTy == IceType_i64) {
- Context.insert<InstFakeDef>(NewReg, New);
- }
- lowerAssign(InstAssign::create(Func, NewReg, New));
+ _dmb();
+ lowerLoadLinkedStoreExclusive(
+ DestTy, Instr->getArg(0),
+ [this, Expected, New, Instr, DestTy](Variable *Tmp) {
+ auto *ExpectedLoR = llvm::cast<Variable>(loOperand(Expected));
+ auto *ExpectedHiR = llvm::cast<Variable>(hiOperand(Expected));
+ auto *TmpLoR = llvm::cast<Variable>(loOperand(Tmp));
+ auto *TmpHiR = llvm::cast<Variable>(hiOperand(Tmp));
+ _cmp(TmpLoR, ExpectedLoR);
+ _cmp(TmpHiR, ExpectedHiR, CondARM32::EQ);
+ // Adding an explicit use of Tmp here, or its live range will not
+ // reach here (only those of Tmp.Lo and Tmp.Hi will.)
+ Context.insert<InstFakeUse>(Tmp);
+ _mov_redefined(ExpectedLoR, TmpLoR);
+ _mov_redefined(ExpectedHiR, TmpHiR);
+ // Same as above.
+ Context.insert<InstFakeUse>(Tmp);
+ return New;
+ },
+ CondARM32::EQ);
+ _dmb();
- _ldrex(TmpReg, Mem);
- Context.insert<InstFakeUse>(Context.getLastInserted()->getDest());
- if (DestTy == IceType_i64) {
- auto *TmpReg64 = llvm::cast<Variable64On32>(TmpReg);
- auto *ExpectedReg64 = llvm::cast<Variable64On32>(ExpectedReg);
- // lowerAssign above has added fake-defs for TmpReg and ExpectedReg. Let's
- // keep liveness happy, shall we?
- Context.insert<InstFakeUse>(TmpReg);
- Context.insert<InstFakeUse>(ExpectedReg);
- _cmp(TmpReg64->getHi(), ExpectedReg64->getHi());
- _cmp(TmpReg64->getLo(), ExpectedReg64->getLo(), CondARM32::EQ);
- } else {
- _cmp(TmpReg, ExpectedReg);
- }
- _strex(Success, NewReg, Mem, CondARM32::EQ);
- if (DestTy == IceType_i64) {
- auto *TmpReg64 = llvm::cast<Variable64On32>(TmpReg);
- auto *Expected64 = llvm::cast<Variable64On32>(Expected);
- _mov_redefined(Expected64->getHi(), TmpReg64->getHi(), CondARM32::NE);
- _mov_redefined(Expected64->getLo(), TmpReg64->getLo(), CondARM32::NE);
- Context.insert<InstFakeDef>(Expected, TmpReg);
- _set_dest_redefined();
- } else {
- _mov_redefined(Expected, TmpReg, CondARM32::NE);
+ lowerAssign(InstAssign::create(Func, Dest, Expected));
+ // The fake-use Expected prevents the assignments to Expected (above)
+ // from being removed if Dest is not used.
+ Context.insert<InstFakeUse>(Expected);
+ // New needs to be alive here, or its live range will end in the
+ // strex instruction.
+ Context.insert<InstFakeUse>(New);
+ return;
}
- _cmp(Success, _0, CondARM32::EQ);
- _br(Retry, CondARM32::NE);
+
+ auto *New = legalizeToReg(Instr->getArg(2));
+ auto *Expected = legalizeToReg(Instr->getArg(1));
+
+ _dmb();
+ lowerLoadLinkedStoreExclusive(
+ DestTy,
+ Instr->getArg(0), [this, Expected, New, Instr, DestTy](Variable *Tmp) {
+ lowerIcmpCond(InstIcmp::Eq, Tmp, Expected);
+ _mov_redefined(Expected, Tmp);
+ return New;
+ }, CondARM32::EQ);
_dmb();
+
lowerAssign(InstAssign::create(Func, Dest, Expected));
Context.insert<InstFakeUse>(Expected);
- if (auto *New64 = llvm::dyn_cast<Variable64On32>(New)) {
- Context.insert<InstFakeUse>(New64->getLo());
- Context.insert<InstFakeUse>(New64->getHi());
- } else {
- Context.insert<InstFakeUse>(New);
- }
+ Context.insert<InstFakeUse>(New);
return;
}
case Intrinsics::AtomicRMW: {
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