Merging r296063:

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r296063 | hans | 2017-02-23 17:16:34 -0800 (Thu, 23 Feb 2017) | 4 lines

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.
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git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_40@296152 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Frontend/InitPreprocessor.cpp b/lib/Frontend/InitPreprocessor.cpp
index 4502c92499a7763ebc098761b3ee29f526077ee6..17603ada11d18d5cf0fb29c12329a33e4c93ab49 100644 (file)
--- a/lib/Frontend/InitPreprocessor.cpp
+++ b/lib/Frontend/InitPreprocessor.cpp
@@ -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.
@@ -881,6 +881,7 @@ 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);
@@ -893,6 +894,7 @@ 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
   }

diff --git a/test/Sema/atomic-ops.c b/test/Sema/atomic-ops.c
index d3ebdf67db0faba722034315479e8e5a3740f0ad..8ebf3eaed4af2dd2b7e027967de24ea64e6f67a0 100644 (file)
--- a/test/Sema/atomic-ops.c
+++ b/test/Sema/atomic-ops.c
@@ -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), "");