NFC: unify clang / LLVM atomic ordering
This makes the C11 / C++11 *ABI* atomic ordering accessible from LLVM,
as discussed in http://reviews.llvm.org/D18200#inline-151433
This re-applies r266573 which I had reverted in r266576.
Original review: http://reviews.llvm.org/D18875
llvm-svn: 266640
diff --git a/llvm/lib/CodeGen/AtomicExpandPass.cpp b/llvm/lib/CodeGen/AtomicExpandPass.cpp
index e0c7fd6..47e69d8 100644
--- a/llvm/lib/CodeGen/AtomicExpandPass.cpp
+++ b/llvm/lib/CodeGen/AtomicExpandPass.cpp
@@ -937,39 +937,6 @@
return true;
}
-// This converts from LLVM's internal AtomicOrdering enum to the
-// memory_order_* value required by the __atomic_* libcalls.
-static int libcallAtomicModel(AtomicOrdering AO) {
- enum {
- AO_ABI_memory_order_relaxed = 0,
- AO_ABI_memory_order_consume = 1,
- AO_ABI_memory_order_acquire = 2,
- AO_ABI_memory_order_release = 3,
- AO_ABI_memory_order_acq_rel = 4,
- AO_ABI_memory_order_seq_cst = 5
- };
-
- switch (AO) {
- case AtomicOrdering::NotAtomic:
- llvm_unreachable("Expected atomic memory order.");
- case AtomicOrdering::Unordered:
- case AtomicOrdering::Monotonic:
- return AO_ABI_memory_order_relaxed;
- // Not implemented yet in llvm:
- // case AtomicOrdering::Consume:
- // return AO_ABI_memory_order_consume;
- case AtomicOrdering::Acquire:
- return AO_ABI_memory_order_acquire;
- case AtomicOrdering::Release:
- return AO_ABI_memory_order_release;
- case AtomicOrdering::AcquireRelease:
- return AO_ABI_memory_order_acq_rel;
- case AtomicOrdering::SequentiallyConsistent:
- return AO_ABI_memory_order_seq_cst;
- }
- llvm_unreachable("Unknown atomic memory order.");
-}
-
// In order to use one of the sized library calls such as
// __atomic_fetch_add_4, the alignment must be sufficient, the size
// must be one of the potentially-specialized sizes, and the value
@@ -1151,12 +1118,15 @@
// TODO: the "order" argument type is "int", not int32. So
// getInt32Ty may be wrong if the arch uses e.g. 16-bit ints.
ConstantInt *SizeVal64 = ConstantInt::get(Type::getInt64Ty(Ctx), Size);
+ assert(Ordering != AtomicOrdering::NotAtomic && "expect atomic MO");
Constant *OrderingVal =
- ConstantInt::get(Type::getInt32Ty(Ctx), libcallAtomicModel(Ordering));
- Constant *Ordering2Val = CASExpected
- ? ConstantInt::get(Type::getInt32Ty(Ctx),
- libcallAtomicModel(Ordering2))
- : nullptr;
+ ConstantInt::get(Type::getInt32Ty(Ctx), (int)toCABI(Ordering));
+ Constant *Ordering2Val = nullptr;
+ if (CASExpected) {
+ assert(Ordering2 != AtomicOrdering::NotAtomic && "expect atomic MO");
+ Ordering2Val =
+ ConstantInt::get(Type::getInt32Ty(Ctx), (int)toCABI(Ordering2));
+ }
bool HasResult = I->getType() != Type::getVoidTy(Ctx);
RTLIB::Libcall RTLibType;