Encode alignment attribute for `atomicrmw`

This is a follow up patch to D83136 adding the align attribute to `atomicwmw`.

Differential Revision: https://reviews.llvm.org/D83465
This commit is contained in:
Guillaume Chatelet 2021-02-11 15:17:37 -05:00 committed by James Y Knight
parent cb41ee92da
commit d06ab79816
7 changed files with 108 additions and 45 deletions

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@ -9701,7 +9701,7 @@ Syntax:
::
atomicrmw [volatile] <operation> <ty>* <pointer>, <ty> <value> [syncscope("<target-scope>")] <ordering> ; yields ty
atomicrmw [volatile] <operation> <ty>* <pointer>, <ty> <value> [syncscope("<target-scope>")] <ordering>[, align <alignment>] ; yields ty
Overview:
"""""""""
@ -9739,6 +9739,13 @@ the ``atomicrmw`` is marked as ``volatile``, then the optimizer is not
allowed to modify the number or order of execution of this
``atomicrmw`` with other :ref:`volatile operations <volatile>`.
The instruction can take an optional ``align`` attribute.
The alignment must be a power of two greater or equal to the size of the
`<value>` type. If unspecified, the alignment is assumed to be equal to the
size of the '<value>' type. Note that this default alignment assumption is
different from the alignment used for the load/store instructions when align
isn't specified.
A ``atomicrmw`` instruction can also take an optional
":ref:`syncscope <syncscope>`" argument.
@ -9759,10 +9766,8 @@ operation argument:
- xor: ``*ptr = *ptr ^ val``
- max: ``*ptr = *ptr > val ? *ptr : val`` (using a signed comparison)
- min: ``*ptr = *ptr < val ? *ptr : val`` (using a signed comparison)
- umax: ``*ptr = *ptr > val ? *ptr : val`` (using an unsigned
comparison)
- umin: ``*ptr = *ptr < val ? *ptr : val`` (using an unsigned
comparison)
- umax: ``*ptr = *ptr > val ? *ptr : val`` (using an unsigned comparison)
- umin: ``*ptr = *ptr < val ? *ptr : val`` (using an unsigned comparison)
- fadd: ``*ptr = *ptr + val`` (using floating point arithmetic)
- fsub: ``*ptr = *ptr - val`` (using floating point arithmetic)

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@ -7499,6 +7499,7 @@ int LLParser::parseAtomicRMW(Instruction *&Inst, PerFunctionState &PFS) {
bool isVolatile = false;
bool IsFP = false;
AtomicRMWInst::BinOp Operation;
MaybeAlign Alignment;
if (EatIfPresent(lltok::kw_volatile))
isVolatile = true;
@ -7531,7 +7532,8 @@ int LLParser::parseAtomicRMW(Instruction *&Inst, PerFunctionState &PFS) {
if (parseTypeAndValue(Ptr, PtrLoc, PFS) ||
parseToken(lltok::comma, "expected ',' after atomicrmw address") ||
parseTypeAndValue(Val, ValLoc, PFS) ||
parseScopeAndOrdering(true /*Always atomic*/, SSID, Ordering))
parseScopeAndOrdering(true /*Always atomic*/, SSID, Ordering) ||
parseOptionalCommaAlign(Alignment, AteExtraComma))
return true;
if (Ordering == AtomicOrdering::Unordered)
@ -7566,11 +7568,12 @@ int LLParser::parseAtomicRMW(Instruction *&Inst, PerFunctionState &PFS) {
if (Size < 8 || (Size & (Size - 1)))
return error(ValLoc, "atomicrmw operand must be power-of-two byte-sized"
" integer");
Align Alignment(
const Align DefaultAlignment(
PFS.getFunction().getParent()->getDataLayout().getTypeStoreSize(
Val->getType()));
AtomicRMWInst *RMWI =
new AtomicRMWInst(Operation, Ptr, Val, Alignment, Ordering, SSID);
new AtomicRMWInst(Operation, Ptr, Val,
Alignment.getValueOr(DefaultAlignment), Ordering, SSID);
RMWI->setVolatile(isVolatile);
Inst = RMWI;
return AteExtraComma ? InstExtraComma : InstNormal;

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@ -5131,29 +5131,55 @@ Error BitcodeReader::parseFunctionBody(Function *F) {
break;
}
case bitc::FUNC_CODE_INST_ATOMICRMW: {
// ATOMICRMW:[ptrty, ptr, val, op, vol, ordering, ssid]
// ATOMICRMW:[ptrty, ptr, val, op, vol, ordering, ssid, align?]
const size_t NumRecords = Record.size();
unsigned OpNum = 0;
Value *Ptr, *Val;
if (getValueTypePair(Record, OpNum, NextValueNo, Ptr, &FullTy) ||
!isa<PointerType>(Ptr->getType()) ||
popValue(Record, OpNum, NextValueNo,
getPointerElementFlatType(FullTy), Val) ||
OpNum + 4 != Record.size())
Value *Ptr = nullptr;
if (getValueTypePair(Record, OpNum, NextValueNo, Ptr, &FullTy))
return error("Invalid record");
AtomicRMWInst::BinOp Operation = getDecodedRMWOperation(Record[OpNum]);
if (!isa<PointerType>(Ptr->getType()))
return error("Invalid record");
Value *Val = nullptr;
if (popValue(Record, OpNum, NextValueNo,
getPointerElementFlatType(FullTy), Val))
return error("Invalid record");
if (!(NumRecords == (OpNum + 4) || NumRecords == (OpNum + 5)))
return error("Invalid record");
const AtomicRMWInst::BinOp Operation =
getDecodedRMWOperation(Record[OpNum]);
if (Operation < AtomicRMWInst::FIRST_BINOP ||
Operation > AtomicRMWInst::LAST_BINOP)
return error("Invalid record");
AtomicOrdering Ordering = getDecodedOrdering(Record[OpNum + 2]);
const bool IsVol = Record[OpNum + 1];
const AtomicOrdering Ordering = getDecodedOrdering(Record[OpNum + 2]);
if (Ordering == AtomicOrdering::NotAtomic ||
Ordering == AtomicOrdering::Unordered)
return error("Invalid record");
SyncScope::ID SSID = getDecodedSyncScopeID(Record[OpNum + 3]);
Align Alignment(
TheModule->getDataLayout().getTypeStoreSize(Val->getType()));
I = new AtomicRMWInst(Operation, Ptr, Val, Alignment, Ordering, SSID);
const SyncScope::ID SSID = getDecodedSyncScopeID(Record[OpNum + 3]);
MaybeAlign Alignment;
if (NumRecords == (OpNum + 5)) {
if (Error Err = parseAlignmentValue(Record[6], Alignment))
return Err;
}
if (!Alignment)
Alignment =
Align(TheModule->getDataLayout().getTypeStoreSize(Val->getType()));
I = new AtomicRMWInst(Operation, Ptr, Val, *Alignment, Ordering, SSID);
FullTy = getPointerElementFlatType(FullTy);
cast<AtomicRMWInst>(I)->setVolatile(Record[OpNum+1]);
cast<AtomicRMWInst>(I)->setVolatile(IsVol);
InstructionList.push_back(I);
break;
}

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@ -3071,6 +3071,7 @@ void ModuleBitcodeWriter::writeInstruction(const Instruction &I,
Vals.push_back(getEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
Vals.push_back(
getEncodedSyncScopeID(cast<AtomicRMWInst>(I).getSyncScopeID()));
Vals.push_back(getEncodedAlign(cast<AtomicRMWInst>(I).getAlign()));
break;
case Instruction::Fence:
Code = bitc::FUNC_CODE_INST_FENCE;

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@ -4327,6 +4327,7 @@ void AssemblyWriter::printInstruction(const Instruction &I) {
} else if (const AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(&I)) {
writeAtomic(RMWI->getContext(), RMWI->getOrdering(),
RMWI->getSyncScopeID());
Out << ", align " << RMWI->getAlign().value();
} else if (const FenceInst *FI = dyn_cast<FenceInst>(&I)) {
writeAtomic(FI->getContext(), FI->getOrdering(), FI->getSyncScopeID());
} else if (const ShuffleVectorInst *SVI = dyn_cast<ShuffleVectorInst>(&I)) {

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@ -734,28 +734,55 @@ define void @atomics(i32* %word) {
; CHECK: %cmpxchg.6 = cmpxchg volatile i32* %word, i32 0, i32 10 seq_cst monotonic
%cmpxchg.7 = cmpxchg weak volatile i32* %word, i32 0, i32 11 syncscope("singlethread") seq_cst monotonic
; CHECK: %cmpxchg.7 = cmpxchg weak volatile i32* %word, i32 0, i32 11 syncscope("singlethread") seq_cst monotonic
%atomicrmw.xchg = atomicrmw xchg i32* %word, i32 12 monotonic
; CHECK: %atomicrmw.xchg = atomicrmw xchg i32* %word, i32 12 monotonic
%atomicrmw.add = atomicrmw add i32* %word, i32 13 monotonic
; CHECK: %atomicrmw.add = atomicrmw add i32* %word, i32 13 monotonic
%atomicrmw.sub = atomicrmw sub i32* %word, i32 14 monotonic
; CHECK: %atomicrmw.sub = atomicrmw sub i32* %word, i32 14 monotonic
%atomicrmw.and = atomicrmw and i32* %word, i32 15 monotonic
; CHECK: %atomicrmw.and = atomicrmw and i32* %word, i32 15 monotonic
%atomicrmw.nand = atomicrmw nand i32* %word, i32 16 monotonic
; CHECK: %atomicrmw.nand = atomicrmw nand i32* %word, i32 16 monotonic
%atomicrmw.or = atomicrmw or i32* %word, i32 17 monotonic
; CHECK: %atomicrmw.or = atomicrmw or i32* %word, i32 17 monotonic
%atomicrmw.xor = atomicrmw xor i32* %word, i32 18 monotonic
; CHECK: %atomicrmw.xor = atomicrmw xor i32* %word, i32 18 monotonic
%atomicrmw.max = atomicrmw max i32* %word, i32 19 monotonic
; CHECK: %atomicrmw.max = atomicrmw max i32* %word, i32 19 monotonic
%atomicrmw.min = atomicrmw volatile min i32* %word, i32 20 monotonic
; CHECK: %atomicrmw.min = atomicrmw volatile min i32* %word, i32 20 monotonic
%atomicrmw.umax = atomicrmw umax i32* %word, i32 21 syncscope("singlethread") monotonic
; CHECK: %atomicrmw.umax = atomicrmw umax i32* %word, i32 21 syncscope("singlethread") monotonic
%atomicrmw.umin = atomicrmw volatile umin i32* %word, i32 22 syncscope("singlethread") monotonic
; CHECK: %atomicrmw.umin = atomicrmw volatile umin i32* %word, i32 22 syncscope("singlethread") monotonic
;; Atomic w/o alignment
%atomicrmw_no_align.xchg = atomicrmw xchg i32* %word, i32 12 monotonic
; CHECK: %atomicrmw_no_align.xchg = atomicrmw xchg i32* %word, i32 12 monotonic
%atomicrmw_no_align.add = atomicrmw add i32* %word, i32 13 monotonic
; CHECK: %atomicrmw_no_align.add = atomicrmw add i32* %word, i32 13 monotonic
%atomicrmw_no_align.sub = atomicrmw sub i32* %word, i32 14 monotonic
; CHECK: %atomicrmw_no_align.sub = atomicrmw sub i32* %word, i32 14 monotonic
%atomicrmw_no_align.and = atomicrmw and i32* %word, i32 15 monotonic
; CHECK: %atomicrmw_no_align.and = atomicrmw and i32* %word, i32 15 monotonic
%atomicrmw_no_align.nand = atomicrmw nand i32* %word, i32 16 monotonic
; CHECK: %atomicrmw_no_align.nand = atomicrmw nand i32* %word, i32 16 monotonic
%atomicrmw_no_align.or = atomicrmw or i32* %word, i32 17 monotonic
; CHECK: %atomicrmw_no_align.or = atomicrmw or i32* %word, i32 17 monotonic
%atomicrmw_no_align.xor = atomicrmw xor i32* %word, i32 18 monotonic
; CHECK: %atomicrmw_no_align.xor = atomicrmw xor i32* %word, i32 18 monotonic
%atomicrmw_no_align.max = atomicrmw max i32* %word, i32 19 monotonic
; CHECK: %atomicrmw_no_align.max = atomicrmw max i32* %word, i32 19 monotonic
%atomicrmw_no_align.min = atomicrmw volatile min i32* %word, i32 20 monotonic
; CHECK: %atomicrmw_no_align.min = atomicrmw volatile min i32* %word, i32 20 monotonic
%atomicrmw_no_align.umax = atomicrmw umax i32* %word, i32 21 syncscope("singlethread") monotonic
; CHECK: %atomicrmw_no_align.umax = atomicrmw umax i32* %word, i32 21 syncscope("singlethread") monotonic
%atomicrmw_no_align.umin = atomicrmw volatile umin i32* %word, i32 22 syncscope("singlethread") monotonic
; CHECK: %atomicrmw_no_align.umin = atomicrmw volatile umin i32* %word, i32 22 syncscope("singlethread") monotonic
;; Atomic w/ alignment
%atomicrmw.xchg = atomicrmw xchg i32* %word, i32 12 monotonic, align 16
; CHECK: %atomicrmw.xchg = atomicrmw xchg i32* %word, i32 12 monotonic, align 16
%atomicrmw.add = atomicrmw add i32* %word, i32 13 monotonic, align 16
; CHECK: %atomicrmw.add = atomicrmw add i32* %word, i32 13 monotonic, align 16
%atomicrmw.sub = atomicrmw sub i32* %word, i32 14 monotonic, align 16
; CHECK: %atomicrmw.sub = atomicrmw sub i32* %word, i32 14 monotonic, align 16
%atomicrmw.and = atomicrmw and i32* %word, i32 15 monotonic, align 16
; CHECK: %atomicrmw.and = atomicrmw and i32* %word, i32 15 monotonic, align 16
%atomicrmw.nand = atomicrmw nand i32* %word, i32 16 monotonic, align 16
; CHECK: %atomicrmw.nand = atomicrmw nand i32* %word, i32 16 monotonic, align 16
%atomicrmw.or = atomicrmw or i32* %word, i32 17 monotonic, align 16
; CHECK: %atomicrmw.or = atomicrmw or i32* %word, i32 17 monotonic, align 16
%atomicrmw.xor = atomicrmw xor i32* %word, i32 18 monotonic, align 16
; CHECK: %atomicrmw.xor = atomicrmw xor i32* %word, i32 18 monotonic, align 16
%atomicrmw.max = atomicrmw max i32* %word, i32 19 monotonic, align 16
; CHECK: %atomicrmw.max = atomicrmw max i32* %word, i32 19 monotonic, align 16
%atomicrmw.min = atomicrmw volatile min i32* %word, i32 20 monotonic, align 16
; CHECK: %atomicrmw.min = atomicrmw volatile min i32* %word, i32 20 monotonic, align 16
%atomicrmw.umax = atomicrmw umax i32* %word, i32 21 syncscope("singlethread") monotonic, align 16
; CHECK: %atomicrmw.umax = atomicrmw umax i32* %word, i32 21 syncscope("singlethread") monotonic, align 16
%atomicrmw.umin = atomicrmw volatile umin i32* %word, i32 22 syncscope("singlethread") monotonic, align 16
; CHECK: %atomicrmw.umin = atomicrmw volatile umin i32* %word, i32 22 syncscope("singlethread") monotonic, align 16
fence acquire
; CHECK: fence acquire
fence release

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@ -4,7 +4,7 @@
; CHECK-LABEL: void @empty()
; CHECK-NEXT: entry:
; CHECK-NEXT: %0 = atomicrmw add i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__llvm_gcov_ctr, i64 0, i64 0), i64 1 monotonic, !dbg [[DBG:![0-9]+]]
; CHECK-NEXT: %0 = atomicrmw add i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__llvm_gcov_ctr, i64 0, i64 0), i64 1 monotonic, align 8, !dbg [[DBG:![0-9]+]]
; CHECK-NEXT: ret void, !dbg [[DBG]]
define dso_local void @empty() !dbg !5 {