There are several issues with the Clang compiler and pixman-mmx.c:
- When not optimizing, it doesn't seem to recognize that an argument
to an __always_inline__ function is compile-time constant. This
results in this error being produced:
fatal error: error in backend: Invalid operand for inline asm
constraint 'K'!
- This inline assembly:
asm ("pmulhuw %1, %0\n\t"
: "+y" (__A)
: "y" (__B)
);
results in
fatal error: error in backend: Unsupported asm: input constraint
with a matching output constraint of incompatible type!
So disable MMX when the compiler is Clang.
#if defined(__GNUC__) && (__GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 4))
#error "Need GCC >= 3.4 for MMX intrinsics"
#endif
+#if defined(__clang__)
+#error "clang chokes on the inline assembly in pixman-mmx.c"
+#endif
#include <mmintrin.h>
int main () {
__m64 v = _mm_cvtsi32_si64 (1);