Some improvements to the handling of C11 atomic types:
- Add atomic-to/from-nonatomic cast types
- Emit atomic operations for arithmetic on atomic types
- Emit non-atomic stores for initialisation of atomic types, but atomic stores and loads for every other store / load
- Add a __atomic_init() intrinsic which does a non-atomic store to an _Atomic() type. This is needed for the corresponding C11 stdatomic.h function.
- Enables the relevant __has_feature() checks. The feature isn't 100% complete yet, but it's done enough that we want people testing it.
Still to do:
- Make the arithmetic operations on atomic types (e.g. Atomic(int) foo = 1; foo++;) use the correct LLVM intrinsic if one exists, not a loop with a cmpxchg.
- Add a signal fence builtin
- Properly set the fenv state in atomic operations on floating point values
- Correctly handle things like _Atomic(_Complex double) which are too large for an atomic cmpxchg on some platforms (this requires working out what 'correctly' means in this context)
- Fix the many remaining corner cases
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148242 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/InitPreprocessor.cpp b/lib/Frontend/InitPreprocessor.cpp
index c736ca3..93c9989 100644
--- a/lib/Frontend/InitPreprocessor.cpp
+++ b/lib/Frontend/InitPreprocessor.cpp
@@ -325,6 +325,14 @@
Builder.defineMacro("__GNUC__", "4");
Builder.defineMacro("__GXX_ABI_VERSION", "1002");
+ // Define macros for the C11 / C++11 memory orderings
+ Builder.defineMacro("__ATOMIC_RELAXED", "0");
+ Builder.defineMacro("__ATOMIC_CONSUME", "1");
+ Builder.defineMacro("__ATOMIC_ACQUIRE", "2");
+ Builder.defineMacro("__ATOMIC_RELEASE", "3");
+ Builder.defineMacro("__ATOMIC_ACQ_REL", "4");
+ Builder.defineMacro("__ATOMIC_SEQ_CST", "5");
+
// As sad as it is, enough software depends on the __VERSION__ for version
// checks that it is necessary to report 4.2.1 (the base GCC version we claim
// compatibility with) first.