shithub: dav1d

Info  •  Files  •  Log  •  Branches

Reset the random seed when testing each CPU type.

Any benchmark that uses random data as input gives bunk results as it
 currently uses differently random data on each run.
This now makes any non-determinism in the tests repeatable across each
 call to check_cpu_flags() and checkasm_check_func().

--- a/tests/checkasm/checkasm.c

+++ b/tests/checkasm/checkasm.c

@@ -133,6 +133,7 @@

     unsigned cpu_flag;

     const char *cpu_flag_name;

     const char *test_name;

+    unsigned int seed;

 } state;

 /* float compare support code */

@@ -413,6 +414,7 @@

         for (int i = 0; tests[i].func; i++) {

             if (state.test_name && strcmp(tests[i].name, state.test_name))

                 continue;

+            srand(state.seed);

             state.current_test_name = tests[i].name;

             tests[i].func();

         }

@@ -429,7 +431,7 @@

 int main(int argc, char *argv[]) {

     (void)func_new, (void)func_ref;

-    unsigned int seed = get_seed();

+    state.seed = get_seed();

     int ret = 0;

     while (argc > 1) {

@@ -447,7 +449,7 @@

         } else if (!strncmp(argv[1], "--test=", 7)) {

             state.test_name = argv[1] + 7;

         } else {

-            seed = strtoul(argv[1], NULL, 10);

+            state.seed = strtoul(argv[1], NULL, 10);

         }

         argc--;

@@ -454,8 +456,7 @@

         argv++;

     }

-    fprintf(stderr, "checkasm: using random seed %u\n", seed);

-    srand(seed);

+    fprintf(stderr, "checkasm: using random seed %u\n", state.seed);

     check_cpu_flag(NULL, 0);

     for (int i = 0; cpus[i].flag; i++)

@@ -521,6 +522,7 @@

     v->ok = 1;

     v->cpu = state.cpu_flag;

     state.current_func_ver = v;

+    srand(state.seed);

     if (state.cpu_flag)

         state.num_checked++;