From a1c056c9d06a6aa184fa3c52a5bbd3562ac386e8 Mon Sep 17 00:00:00 2001 From: Noah Goldstein Date: Sat, 18 Sep 2021 16:13:34 -0500 Subject: [PATCH] benchtests: Improve reliability of memcmp benchmarks No bug. Remove reallocation of bufs between implementation tests. Move initialization outside of foreach implementation test loop. Increase iteration count. Generally before this commit was seeing a great deal of variability between runs. The goal of this commit is to make the results more reliable. Benchtests build and bench-memcmp succeeding. Signed-off-by: Noah Goldstein --- benchtests/bench-memcmp.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/benchtests/bench-memcmp.c b/benchtests/bench-memcmp.c index 744c7ec5ba..0d6a93bf29 100644 --- a/benchtests/bench-memcmp.c +++ b/benchtests/bench-memcmp.c @@ -63,7 +63,7 @@ static void do_one_test (json_ctx_t *json_ctx, impl_t *impl, const CHAR *s1, const CHAR *s2, size_t len, int exp_result) { - size_t i, iters = INNER_LOOP_ITERS8; + size_t i, iters = INNER_LOOP_ITERS_LARGE; timing_t start, stop, cur; TIMING_NOW (start); @@ -103,20 +103,19 @@ do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len, json_attr_uint (json_ctx, "result", (double) exp_result); json_array_begin (json_ctx, "timings"); + s1 = (CHAR *)(buf1 + align1); + s2 = (CHAR *)(buf2 + align2); + + for (i = 0; i < len; i++) + s1[i] = s2[i] = 1 + (23 << ((CHARBYTES - 1) * 8)) * i % MAX_CHAR; + + s1[len] = align1; + s2[len] = align2; + s2[len - 1] -= exp_result; + FOR_EACH_IMPL (impl, 0) { - s1 = (CHAR *) (buf1 + align1); - s2 = (CHAR *) (buf2 + align2); - - for (i = 0; i < len; i++) - s1[i] = s2[i] = 1 + (23 << ((CHARBYTES - 1) * 8)) * i % MAX_CHAR; - - s1[len] = align1; - s2[len] = align2; - s2[len - 1] -= exp_result; - do_one_test (json_ctx, impl, s1, s2, len, exp_result); - alloc_bufs (); } json_array_end (json_ctx);