Re: 16 byte alignment hint for sse vectorization

2006-11-08 Thread Dorit Nuzman
I entirely agree. There definitely should be a PR for this, if there isn't already. dorit "Michael James" <[EMAIL PROTECTED]> wrote on 05/11/2006 22:03:47: > Hello Dorit, > > Thank you for the list of references. > > What I gathered from reading this is that alignment attributes applied > to th

Re: 16 byte alignment hint for sse vectorization

2006-11-05 Thread Michael James
Hello Dorit, Thank you for the list of references. What I gathered from reading this is that alignment attributes applied to the base element of an array are causing problems for other legitimate uses of this attribute. It is basically stupid to specify the base type of an array be aligned becau

Re: 16 byte alignment hint for sse vectorization

2006-11-05 Thread Mike Stump
On Nov 4, 2006, at 11:00 AM, Michael James wrote: Does anyone have a suggestion? #define SSE __attribute__((aligned (16))) typedef float matrix_sub_t[1024] SSE; typedef matrix_sub_t matrix_t[100]; matrix_t a, b, c; void calc(matrix_sub_t * restrict ap, matrix_sub_t * restrict bp,

Re: 16 byte alignment hint for sse vectorization

2006-11-05 Thread Dorit Nuzman
Unfortunately there's no way to specify alignment attribute of pointers in GCC - the syntax was allowed in the past but not really supported correctly, and then entirely disallowed (by this patch http://gcc.gnu.org/ml/gcc-patches/2005-04/msg02284.html). This issue was discussed in details in these

16 byte alignment hint for sse vectorization

2006-11-04 Thread Michael James
Hello, I have been playing with gcc's new (to me) auto vectorization optimizations. I have a particular loop for which I have made external provisions to ensure that the data is 16-byte aligned. I have tried everything I can think of to give gcc the hint that it is operating on aligned data, but