Attachment 180600 Details for Bug 217611 – FP registers vs. signals

FP registers vs. signals

fptst.c (text/plain), 1.73 KB, created by Andrew "RhodiumToad" Gierth on 2017-03-07 13:21:24 UTC

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Creator: Andrew "RhodiumToad" Gierth

Created: 2017-03-07 13:21:24 UTC

Size: 1.73 KB

patch

obsolete

>
>#include <stdio.h>
>#include <stdlib.h>
>
>#include <unistd.h>
>#include <sys/signal.h>
>#include <sys/time.h>
>
>volatile sig_atomic_t sigcnt = 0;
>volatile double z;
>
>void tick(int sig)
>{
>    double x;
>
>    x = ++sigcnt;
>    x *= 2.1;
>    z += x;
>}
>
>void show_result(const char *name, double actual, double expected)
>{
>    printf("%s: actual=%f expected=%f\n", name, actual, expected);
>}
>
>void loops(void)
>{
>    double h0 = 0;
>    double h1 = 1;
>    double h2 = 2;
>    double h3 = 3;
>    double h4 = 4;
>    double h5 = 5;
>    double h6 = 6;
>    double h7 = 7;
>    int i;
>    int n = 100000000;
>
>    for (i = 0; i < n; ++i)
>    {
>	/* all these lines add 1; the complexity is just to keep the
>	 * VFP regs in play as much as possible */
>	h0 += (h7 - h6) + (h6 - h5) + (h5 - h4) + (h4 - h3) + (h3 - h2) - 4;
>	h1 += (h7 - h6) + (h6 - h5) + (h5 - h4) + (h4 - h3) + (h3 - h2) - 4;
>	h2 += (h7 - h6) + (h6 - h5) + (h5 - h4) + (h4 - h3) + (h1 - h0) - 4;
>	h3 += (h7 - h6) + (h6 - h5) + (h5 - h4) + (h2 - h1) + (h1 - h0) - 4;
>	h4 += (h7 - h6) + (h6 - h5) + (h3 - h2) + (h2 - h1) + (h1 - h0) - 4;
>	h5 += (h7 - h6) + (h4 - h3) + (h3 - h2) + (h2 - h1) + (h1 - h0) - 4;
>	h6 += (h5 - h4) + (h4 - h3) + (h3 - h2) + (h2 - h1) + (h1 - h0) - 4;
>	h7 += (h5 - h4) + (h4 - h3) + (h3 - h2) + (h2 - h1) + (h1 - h0) - 4;
>    }
>
>    show_result("h0", h0, n + 0.0);
>    show_result("h1", h1, n + 1.0);
>    show_result("h2", h2, n + 2.0);
>    show_result("h3", h3, n + 3.0);
>    show_result("h4", h4, n + 4.0);
>    show_result("h5", h5, n + 5.0);
>    show_result("h6", h6, n + 6.0);
>    show_result("h7", h7, n + 7.0);
>}
>
>int main(int argc, char **argv)
>{
>    int i;
>
>    signal(SIGALRM, tick);
>    if (argc > 1)
>      alarm(1);
>    
>    fprintf(stderr, "entering...\n");
>
>    loops();
>
>    return 0;
>}
>

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Attachments on bug 217611: 180600 | 180669