FX wrote:
Hi all,
I have picked up what seems to be a simple patch from PR36399, but I don't know
enough assembler to tell whether it's fixing it completely or not.
The following function:
#include <xmmintrin.h>
__m128i r(__m128 d1, __m128 d2, __m128 d3, __m128i r, int t, __m128i s) {return
r+s;}
is compiled by Apple's GCC into:
pushl %ebp
movl %esp, %ebp
subl $72, %esp
movaps %xmm0, -24(%ebp)
movaps %xmm1, -40(%ebp)
movaps %xmm2, -56(%ebp)
movdqa %xmm3, -72(%ebp) #
movdqa 24(%ebp), %xmm0 #
paddq -72(%ebp), %xmm0 #
leave
ret
Instead of lines marked with #, FSF's GCC gives:
movdqa 40(%ebp), %xmm1
movdqa 8(%ebp), %xmm0
paddq %xmm1, %xmm0
By fixing SSE_REGPARM_MAX in config/i386/i386.h (following Apple's compiler
value), I get GCC now generates:
movdqa %xmm3, -72(%ebp)
movdqa 24(%ebp), %xmm0
movdqa -72(%ebp), %xmm1
paddq %xmm1, %xmm0
The first two lines are identical to Apple, but the last two don't. They seem
OK to me, but I don't know enough assembler to be really sure. Could someone
confirm the two are equivalent?
Apparently the same as far as what is returned in xmm0.