ranjith kumar <ranjit_kumar_b4u@xxxxxxxxxxx> writes:
> 1) Seems that all defintions for MMX, SSE and SSE2
> are deinred in mmtrin.h,xmmintrin.h and emmintrin.h
> header files respectively. Am I right?
Yes.
> 2) In those header files all functions call
> _builtin_ia32_*. Where those functions(body) are
> defined?
They are intrinsic functions automatically defined by the compiler.
> 3) I thought that associated with each SIMD
> instruction defined in Intel-ia-32-architectures
> manual(Basic architecture) there is one function
> defined in those header files.
> But for some instructions no functions were defined in
> those header files.(For example MOVDQA instruction)
> Also those header files contain some more functions
> for which no SIMD assembly instruction exist.Example
> in emmintrin.h
> static __inline __m128i
> _mm_load_si128 (__m128i const *__P)
> {
> return (__m128i) __builtin_ia32_loaddqa ((char
> const *)__P);
> }
> What could be the reason?
Those header files follow the implementation described by Intel.
Ian
