mirror of
https://git.proxmox.com/git/llvm-toolchain
synced 2025-11-04 07:08:39 +00:00
32 lines
1.4 KiB
Diff
32 lines
1.4 KiB
Diff
Lock is_always_lock free test fails on i386 because std::atomic is aligned
|
|
to 8 bytes while long long is aligned to 4 bytes. clang can't generate inline
|
|
code for unaligned 8 byte atomics even tough instruction set and gcc support
|
|
it.
|
|
|
|
That makes it expected thaqt ATOMIC_LLONG_LOCK_FREE and
|
|
std::atomic<long long>::is_always_lock_free don't match on i386. Correct test
|
|
for std::atomic<long long> is to check if target cpu support cmpxchg8 instruction.
|
|
To set instruction support one can check __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 define.
|
|
|
|
Bug: https://llvm.org/bugs/show_bug.cgi?id=19355
|
|
|
|
Index: llvm-toolchain-snapshot_7~svn337372/libcxx/test/std/atomics/atomics.lockfree/isalwayslockfree.pass.cpp
|
|
===================================================================
|
|
--- llvm-toolchain-snapshot_7~svn337372.orig/libcxx/test/std/atomics/atomics.lockfree/isalwayslockfree.pass.cpp
|
|
+++ llvm-toolchain-snapshot_7~svn337372/libcxx/test/std/atomics/atomics.lockfree/isalwayslockfree.pass.cpp
|
|
@@ -20,6 +20,14 @@
|
|
# error Feature test macro missing.
|
|
#endif
|
|
|
|
+#if defined(__i386__) && defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8)
|
|
+/* Fix for clang setting __GCC_ATOMIC_LLONG_LOCK_FREE incorecctly for x86
|
|
+ * https://llvm.org/bugs/show_bug.cgi?id=19355
|
|
+ */
|
|
+#undef ATOMIC_LLONG_LOCK_FREE
|
|
+#define ATOMIC_LLONG_LOCK_FREE 2
|
|
+#endif
|
|
+
|
|
template <typename T> void checkAlwaysLockFree() {
|
|
if (std::atomic<T>::is_always_lock_free)
|
|
assert(std::atomic<T>().is_lock_free());
|