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Revert r291477 "[Frontend] Correct values of ATOMIC_*_LOCK_FREE to match builtin" 

It caused PR31864. There is a patch in progress to fix that, but let's
revert in the meantime.

llvm-svn: 296063
This commit is contained in:
Hans Wennborg 2017-02-24 01:16:34 +00:00
parent 7f809b2fbd
commit 260c6d4555
2 changed files with 10 additions and 4 deletions
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10
clang/lib/Frontend/InitPreprocessor.cpp
View File

@ -286,12 +286,12 @@ static void DefineFastIntType(unsigned TypeWidth, bool IsSigned,
/// Get the value the ATOMIC_*_LOCK_FREE macro should have for a type with
/// the specified properties.
static const char *getLockFreeValue(unsigned TypeWidth, unsigned InlineWidth) {
static const char *getLockFreeValue(unsigned TypeWidth, unsigned TypeAlign,
unsigned InlineWidth) {
// Fully-aligned, power-of-2 sizes no larger than the inline
// width will be inlined as lock-free operations.
// Note: we do not need to check alignment since _Atomic(T) is always
// appropriately-aligned in clang.
if ((TypeWidth & (TypeWidth - 1)) == 0 && TypeWidth <= InlineWidth)
if (TypeWidth == TypeAlign && (TypeWidth & (TypeWidth - 1)) == 0 &&
TypeWidth <= InlineWidth)
return "2"; // "always lock free"
// We cannot be certain what operations the lib calls might be
// able to implement as lock-free on future processors.
@ -886,6 +886,7 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
#define DEFINE_LOCK_FREE_MACRO(TYPE, Type) \
Builder.defineMacro("__GCC_ATOMIC_" #TYPE "_LOCK_FREE", \
getLockFreeValue(TI.get##Type##Width(), \
TI.get##Type##Align(), \
InlineWidthBits));
DEFINE_LOCK_FREE_MACRO(BOOL, Bool);
DEFINE_LOCK_FREE_MACRO(CHAR, Char);
@ -898,6 +899,7 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
DEFINE_LOCK_FREE_MACRO(LLONG, LongLong);
Builder.defineMacro("__GCC_ATOMIC_POINTER_LOCK_FREE",
getLockFreeValue(TI.getPointerWidth(0),
TI.getPointerAlign(0),
InlineWidthBits));
#undef DEFINE_LOCK_FREE_MACRO
}

4
clang/test/Sema/atomic-ops.c
View File

@ -14,7 +14,11 @@ _Static_assert(__GCC_ATOMIC_WCHAR_T_LOCK_FREE == 2, "");
_Static_assert(__GCC_ATOMIC_SHORT_LOCK_FREE == 2, "");
_Static_assert(__GCC_ATOMIC_INT_LOCK_FREE == 2, "");
_Static_assert(__GCC_ATOMIC_LONG_LOCK_FREE == 2, "");
#ifdef __i386__
_Static_assert(__GCC_ATOMIC_LLONG_LOCK_FREE == 1, "");
#else
_Static_assert(__GCC_ATOMIC_LLONG_LOCK_FREE == 2, "");
#endif
_Static_assert(__GCC_ATOMIC_POINTER_LOCK_FREE == 2, "");
_Static_assert(__c11_atomic_is_lock_free(1), "");