match the feature set of the function that they're being called from.
This ensures that we can effectively diagnose some[1] code that would
instead ICE in the backend with a failure to select message.
Example:
__m128d foo(__m128d a, __m128d b) {
return __builtin_ia32_addsubps(b, a);
}
compiled for normal x86_64 via:
clang -target x86_64-linux-gnu -c
would fail to compile in the back end because the normal subtarget
features for x86_64 only include sse2 and the builtin requires sse3.
[1] We're still not erroring on:
__m128i bar(__m128i const *p) { return _mm_lddqu_si128(p); }
where we should fail and error on an always_inline function being
inlined into a function that doesn't support the subtarget features
required.
llvm-svn: 250473
Richard Smith