On Mon, 21 Jan 2013, Peng Yu wrote:
The following commands showed that -msse2 has to be used with -O (or
its variants -O1, -O2, etc.) But I don't find this documented in the
gcc manual. Does anybody know where this is documented? Thanks!
It is just luck that makes it sometimes work.
#include <xmmintrin.h>
#include <stdio.h>
int main() {
float p[4]={1,2,3,4};
__m128 a = _mm_load_ps(p);
_mm_load_ps requires a 16-byte alignment.
float p1[4];
_mm_store_ps(p1, a);
for(int i=0; i < 4; i++) {
printf("%g\n", p1[i]);
}
}
--
Marc Glisse
