NFC: make AtomicOrdering an enum class
Summary:
In the context of http://wg21.link/lwg2445 C++ uses the concept of
'stronger' ordering but doesn't define it properly. This should be fixed
in C++17 barring a small question that's still open.
The code currently plays fast and loose with the AtomicOrdering
enum. Using an enum class is one step towards tightening things. I later
also want to tighten related enums, such as clang's
AtomicOrderingKind (which should be shared with LLVM as a 'C++ ABI'
enum).
This change touches a few lines of code which can be improved later, I'd
like to keep it as NFC for now as it's already quite complex. I have
related changes for clang.
As a follow-up I'll add:
bool operator<(AtomicOrdering, AtomicOrdering) = delete;
bool operator>(AtomicOrdering, AtomicOrdering) = delete;
bool operator<=(AtomicOrdering, AtomicOrdering) = delete;
bool operator>=(AtomicOrdering, AtomicOrdering) = delete;
This is separate so that clang and LLVM changes don't need to be in sync.
Reviewers: jyknight, reames
Subscribers: jyknight, llvm-commits
Differential Revision: http://reviews.llvm.org/D18775
llvm-svn: 265602
diff --git a/llvm/lib/Analysis/AliasAnalysis.cpp b/llvm/lib/Analysis/AliasAnalysis.cpp
index 453bc3d..117f8cb 100644
--- a/llvm/lib/Analysis/AliasAnalysis.cpp
+++ b/llvm/lib/Analysis/AliasAnalysis.cpp
@@ -389,7 +389,7 @@
ModRefInfo AAResults::getModRefInfo(const AtomicCmpXchgInst *CX,
const MemoryLocation &Loc) {
// Acquire/Release cmpxchg has properties that matter for arbitrary addresses.
- if (CX->getSuccessOrdering() > Monotonic)
+ if (isStrongerThanMonotonic(CX->getSuccessOrdering()))
return MRI_ModRef;
// If the cmpxchg address does not alias the location, it does not access it.
@@ -402,7 +402,7 @@
ModRefInfo AAResults::getModRefInfo(const AtomicRMWInst *RMW,
const MemoryLocation &Loc) {
// Acquire/Release atomicrmw has properties that matter for arbitrary addresses.
- if (RMW->getOrdering() > Monotonic)
+ if (isStrongerThanMonotonic(RMW->getOrdering()))
return MRI_ModRef;
// If the atomicrmw address does not alias the location, it does not access it.