Commit e6ba2e0c authored by Hans Wennborg's avatar Hans Wennborg
Browse files

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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llvm-svn: 296152
parent ad64c684

clang/lib/Frontend/InitPreprocessor.cpp

+6 −4
Original line number Diff line number Diff line
@@ -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

  }

clang/test/Sema/atomic-ops.c

+4 −0
Original line number Diff line number Diff line
@@ -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), "");