IR: add a second ordering operand to cmpxhg for failure
The syntax for "cmpxchg" should now look something like:
cmpxchg i32* %addr, i32 42, i32 3 acquire monotonic
where the second ordering argument gives the required semantics in the case
that no exchange takes place. It should be no stronger than the first ordering
constraint and cannot be either "release" or "acq_rel" (since no store will
have taken place).
rdar://problem/15996804
llvm-svn: 203559
diff --git a/llvm/lib/IR/Instructions.cpp b/llvm/lib/IR/Instructions.cpp
index d874411..3aa8413 100644
--- a/llvm/lib/IR/Instructions.cpp
+++ b/llvm/lib/IR/Instructions.cpp
@@ -1216,12 +1216,14 @@
//===----------------------------------------------------------------------===//
void AtomicCmpXchgInst::Init(Value *Ptr, Value *Cmp, Value *NewVal,
- AtomicOrdering Ordering,
+ AtomicOrdering SuccessOrdering,
+ AtomicOrdering FailureOrdering,
SynchronizationScope SynchScope) {
Op<0>() = Ptr;
Op<1>() = Cmp;
Op<2>() = NewVal;
- setOrdering(Ordering);
+ setSuccessOrdering(SuccessOrdering);
+ setFailureOrdering(FailureOrdering);
setSynchScope(SynchScope);
assert(getOperand(0) && getOperand(1) && getOperand(2) &&
@@ -1234,30 +1236,38 @@
assert(getOperand(2)->getType() ==
cast<PointerType>(getOperand(0)->getType())->getElementType()
&& "Ptr must be a pointer to NewVal type!");
- assert(Ordering != NotAtomic &&
+ assert(SuccessOrdering != NotAtomic &&
"AtomicCmpXchg instructions must be atomic!");
+ assert(FailureOrdering != NotAtomic &&
+ "AtomicCmpXchg instructions must be atomic!");
+ assert(SuccessOrdering >= FailureOrdering &&
+ "AtomicCmpXchg success ordering must be at least as strong as fail");
+ assert(FailureOrdering != Release && FailureOrdering != AcquireRelease &&
+ "AtomicCmpXchg failure ordering cannot include release semantics");
}
AtomicCmpXchgInst::AtomicCmpXchgInst(Value *Ptr, Value *Cmp, Value *NewVal,
- AtomicOrdering Ordering,
+ AtomicOrdering SuccessOrdering,
+ AtomicOrdering FailureOrdering,
SynchronizationScope SynchScope,
Instruction *InsertBefore)
: Instruction(Cmp->getType(), AtomicCmpXchg,
OperandTraits<AtomicCmpXchgInst>::op_begin(this),
OperandTraits<AtomicCmpXchgInst>::operands(this),
InsertBefore) {
- Init(Ptr, Cmp, NewVal, Ordering, SynchScope);
+ Init(Ptr, Cmp, NewVal, SuccessOrdering, FailureOrdering, SynchScope);
}
AtomicCmpXchgInst::AtomicCmpXchgInst(Value *Ptr, Value *Cmp, Value *NewVal,
- AtomicOrdering Ordering,
+ AtomicOrdering SuccessOrdering,
+ AtomicOrdering FailureOrdering,
SynchronizationScope SynchScope,
BasicBlock *InsertAtEnd)
: Instruction(Cmp->getType(), AtomicCmpXchg,
OperandTraits<AtomicCmpXchgInst>::op_begin(this),
OperandTraits<AtomicCmpXchgInst>::operands(this),
InsertAtEnd) {
- Init(Ptr, Cmp, NewVal, Ordering, SynchScope);
+ Init(Ptr, Cmp, NewVal, SuccessOrdering, FailureOrdering, SynchScope);
}
//===----------------------------------------------------------------------===//
@@ -3596,7 +3606,8 @@
AtomicCmpXchgInst *AtomicCmpXchgInst::clone_impl() const {
AtomicCmpXchgInst *Result =
new AtomicCmpXchgInst(getOperand(0), getOperand(1), getOperand(2),
- getOrdering(), getSynchScope());
+ getSuccessOrdering(), getFailureOrdering(),
+ getSynchScope());
Result->setVolatile(isVolatile());
return Result;
}