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From: "jb at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug fortran/29549] matmul slow for complex matrices Date: Sat, 04 Nov 2006 21:24:00 -0000 [thread overview] Message-ID: <20061104212424.31244.qmail@sourceware.org> (raw) In-Reply-To: <bug-29549-1719@http.gcc.gnu.org/bugzilla/> ------- Comment #3 from jb at gcc dot gnu dot org 2006-11-04 21:24 ------- Well, redoing the C benchmark above to use 1d arrays and manual index calculations, the results are now essentially the same as for the Fortran version. And a commercial compiler produces about the same results for the Fortran version as gfortran, which means the reason for our poor complex matmul performance lies elsewhere. #include <stdio.h> #include <stdlib.h> #include <complex.h> #include <sys/time.h> #include <time.h> int main(void) { int n = 300; complex float *a, *b, *c; int i, j, k, tc; a = malloc (n*n * sizeof (*a)); b = malloc (n*n * sizeof (*b)); c = malloc (n*n * sizeof (*c)); struct timeval tv, tv2; float res; FILE *fp; tc = 0; for (i = 0; i < n*n; i++) { a[i] = i*10.0 + 100.0*I; b[i] = 1.0 + 42.0*I; c[i] = 0.0 + 0.0*I; } gettimeofday (&tv, NULL); for (i = 0; i < n; i++) { for (j = 0; j < n; j++) { c[i*n + j] = 0.0 + 0.0*I; for (k = 0; k < n; k++) { c[i*n + j] = c[i*n + j] + a[i*n + k] * b[k*n + j]; tc++; } } } gettimeofday (&tv2, NULL); res = tv2.tv_sec - tv.tv_sec + (tv2.tv_usec - tv.tv_usec) / 1000000.0; printf ("gemm time: %f\n", res); fp = fopen ("c-matrix", "w"); for (i = 0; i < n; i++) { for (j = 0; j<n; j++) { fprintf (fp, "%f ", c[i*n + j]); } fprintf (fp, "\n"); } fclose (fp); printf ("trip count: %i\n", tc); } -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29549
next prev parent reply other threads:[~2006-11-04 21:24 UTC|newest] Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top 2006-10-22 15:58 [Bug fortran/29549] New: " tobias dot burnus at physik dot fu-berlin dot de 2006-11-04 14:15 ` [Bug fortran/29549] " jb at gcc dot gnu dot org 2006-11-04 20:34 ` jb at gcc dot gnu dot org 2006-11-04 21:24 ` jb at gcc dot gnu dot org [this message] 2006-11-04 22:17 ` jb at gcc dot gnu dot org 2008-02-10 19:20 ` jb at gcc dot gnu dot org 2008-02-10 22:48 ` tkoenig at gcc dot gnu dot org 2008-02-16 18:50 ` fxcoudert at gcc dot gnu dot org 2008-02-16 19:01 ` fxcoudert at gcc dot gnu dot org 2008-02-16 21:59 ` rguenth at gcc dot gnu dot org 2008-02-16 22:33 ` jb at gcc dot gnu dot org 2008-02-19 19:34 ` jb at gcc dot gnu dot org 2008-02-25 19:22 ` jb at gcc dot gnu dot org 2008-02-25 19:28 ` jb at gcc dot gnu dot org 2008-02-26 21:15 ` jb at gcc dot gnu dot org
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