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
diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index 1acfe70..749dd9b 100644
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -286,12 +286,12 @@
/// 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 @@
#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 @@
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
}