LDC 0.11.0 Beta 3

[bearophile]

> But gcc compiles similar code (that uses __m128d instead of 
> double2) using the instruction "haddpd", that I think is 
> shorter/more efficient here.

C code:


#include <emmintrin.h>
double foo(const __m128d x) {
     return x[0] + x[1];
}
int main() {
     __m128d x = _mm_set_pd(1.0, 2.0);
     return (int)foo(x);
}


Compiled with:

gcc -S -Ofast -fomit-frame-pointer -march=native -mfpmath=sse 
-msse2 test.c -o test.s

GCC version 4.8.0

The asm of "foo":

_foo:
     subl    $20, %esp
     haddpd  %xmm0, %xmm0
     movsd   %xmm0, (%esp)
     fldl    (%esp)
     addl    $20, %esp
     ret


Bye,
bearophile