[libcxx-commits] [PATCH] D119931: [libcxx][atomic] Remove workaround for PR31864
Kai Luo via Phabricator via libcxx-commits
libcxx-commits at lists.llvm.org
Wed Feb 16 06:03:25 PST 2022
lkail updated this revision to Diff 409225.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D119931/new/
https://reviews.llvm.org/D119931
Files:
libcxx/test/std/atomics/atomics.lockfree/isalwayslockfree.pass.cpp
Index: libcxx/test/std/atomics/atomics.lockfree/isalwayslockfree.pass.cpp
===================================================================
--- libcxx/test/std/atomics/atomics.lockfree/isalwayslockfree.pass.cpp
+++ libcxx/test/std/atomics/atomics.lockfree/isalwayslockfree.pass.cpp
@@ -29,38 +29,25 @@
assert(std::atomic<T>().is_lock_free());
}
-// FIXME: This separate test is needed to work around llvm.org/PR31864
-// which causes ATOMIC_LLONG_LOCK_FREE to be defined as '1' in 32-bit builds
-// even though __atomic_always_lock_free returns true for the same type.
-constexpr bool NeedWorkaroundForPR31864 =
-#if defined(__clang__)
-(sizeof(void*) == 4); // Needed on 32 bit builds
+void checkLongLongTypes() {
+ static_assert(std::atomic<long long>::is_always_lock_free == __atomic_always_lock_free(sizeof(long long), 0), "");
+ static_assert(std::atomic<unsigned long long>::is_always_lock_free ==
+ __atomic_always_lock_free(sizeof(unsigned long long), 0),
+ "");
+// This looks like a GCC bug, it failed with static_assert, but succeeded with assert.
+#ifdef __GNUC__
+ assert(__atomic_always_lock_free(sizeof(long long), (long long*)alignof(long long)) == (2 == ATOMIC_LLONG_LOCK_FREE));
+ assert(__atomic_always_lock_free(sizeof(unsigned long long), (unsigned long long*)alignof(unsigned long long)) ==
+ (2 == ATOMIC_LLONG_LOCK_FREE));
#else
-false;
+ static_assert(__atomic_always_lock_free(sizeof(long long), (long long*)alignof(long long)) ==
+ (2 == ATOMIC_LLONG_LOCK_FREE),
+ "");
+ static_assert(
+ __atomic_always_lock_free(sizeof(unsigned long long), (unsigned long long*)alignof(unsigned long long)) ==
+ (2 == ATOMIC_LLONG_LOCK_FREE),
+ "");
#endif
-
-template <bool Disable = NeedWorkaroundForPR31864,
- std::enable_if_t<!Disable>* = nullptr,
- class LLong = long long,
- class ULLong = unsigned long long>
-void checkLongLongTypes() {
- static_assert(std::atomic<LLong>::is_always_lock_free == (2 == ATOMIC_LLONG_LOCK_FREE), "");
- static_assert(std::atomic<ULLong>::is_always_lock_free == (2 == ATOMIC_LLONG_LOCK_FREE), "");
-}
-
-// Used to make the calls to __atomic_always_lock_free dependent on a template
-// parameter.
-template <class T> constexpr size_t getSizeOf() { return sizeof(T); }
-
-template <bool Enable = NeedWorkaroundForPR31864,
- std::enable_if_t<Enable>* = nullptr,
- class LLong = long long,
- class ULLong = unsigned long long>
-void checkLongLongTypes() {
- constexpr bool ExpectLockFree = __atomic_always_lock_free(getSizeOf<LLong>(), 0);
- static_assert(std::atomic<LLong>::is_always_lock_free == ExpectLockFree, "");
- static_assert(std::atomic<ULLong>::is_always_lock_free == ExpectLockFree, "");
- static_assert((0 != ATOMIC_LLONG_LOCK_FREE) == ExpectLockFree, "");
}
void run()
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D119931.409225.patch
Type: text/x-patch
Size: 2862 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/libcxx-commits/attachments/20220216/68afeeb9/attachment-0001.bin>
More information about the libcxx-commits
mailing list