gcc and SIMD

[ranjith kumar]

--- Ian Lance Taylor <iant@google.com> wrote:

> ranjith kumar <ranjit_kumar_b4u@yahoo.co.uk> 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.
Please tell me in what file they are defined.

> 
> > 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.
In which file they are described?
The thing is that I want to go into internals of it.
Thanks in advance.
> 
> Ian
> 



		
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