Import r243925 from the upstream clang release_37 branch:

Reverting r239883 and r240720:
------------------------------------------------------------------------
r239883 | echristo | 2015-06-17 00:09:32 -0700 (Wed, 17 Jun 2015) | 16 lines

Update the intel intrinsic headers to use the target attribute support.

This involved removing the conditional inclusion and replacing them
with target attributes matching the original conditional inclusion
and checks. The testcase update removes the macro checks for each
file and replaces them with usage of the __target__ attribute, e.g.:

int __attribute__((__target__(("sse3")))) foo(int a) {
  _mm_mwait(0, 0);
  return 4;
}

This usage does require the enclosing function have the requisite
__target__ attribute for inlining and code generation - also for
any macro intrinsic uses in the enclosing function. There's no change
for existing uses of the intrinsic headers.
------------------------------------------------------------------------

------------------------------------------------------------------------
r240720 | silvas | 2015-06-25 16:22:11 -0700 (Thu, 25 Jun 2015) | 6 lines

Remove `requires` for x86 CPU features.

Ever since the target attributes change, we don't need to guard these
headers with `requires`. Actually it's a bit worse, because if we do
then they are included textually under the covers, causing declarations
to appear in submodules they aren't supposed to be in.
------------------------------------------------------------------------

This reverts the changes to the intrinsics headers in trunk, which could
result in some ports' configure scripts misdetecting SSE (and higher)
support.

1 files changed, 7 insertions, 1 deletions

diff --git a/contrib/llvm/tools/clang/lib/Headers/fma4intrin.h b/contrib/llvm/tools/clang/lib/Headers/fma4intrin.h
index f117887..d6405cf 100644
--- a/contrib/llvm/tools/clang/lib/Headers/fma4intrin.h
+++ b/contrib/llvm/tools/clang/lib/Headers/fma4intrin.h
@@ -28,10 +28,14 @@
 #ifndef __FMA4INTRIN_H
 #define __FMA4INTRIN_H
 
+#ifndef __FMA4__
+# error "FMA4 instruction set is not enabled"
+#else
+
 #include <pmmintrin.h>
 
 /* Define the default attributes for the functions in this file. */
-#define __DEFAULT_FN_ATTRS __attribute__((__always_inline__, __nodebug__, __target__("fma4")))
+#define __DEFAULT_FN_ATTRS __attribute__((__always_inline__, __nodebug__))
 
 static __inline__ __m128 __DEFAULT_FN_ATTRS
 _mm_macc_ps(__m128 __A, __m128 __B, __m128 __C)
@@ -227,4 +231,6 @@ _mm256_msubadd_pd(__m256d __A, __m256d __B, __m256d __C)
 
 #undef __DEFAULT_FN_ATTRS
 
+#endif /* __FMA4__ */
+
 #endif /* __FMA4INTRIN_H */