minor hash_fn() followups

- remove an odd space
  - "rounds" is fine, but "bits" is more precise
  - after fixing a typo, four parallel hashes no
    longer was any faster (or slower) than three,
    so I consider that TODO now done

Change-Id: I7fff29640c1238229418bd8385b3b3aeae4ad68f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/338621
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
This commit is contained in:
Mike Klein 2020-11-25 09:35:09 -06:00 committed by Skia Commit-Bot
parent 56b1b80795
commit 6e5079a280

View File

@ -39,7 +39,7 @@
std::array<uint32_t, 256> t; std::array<uint32_t, 256> t;
for (int i = 0; i < 256; i++) { for (int i = 0; i < 256; i++) {
t[i] = i; t[i] = i;
for (int rounds = 8; rounds --> 0; ) { for (int bits = 8; bits --> 0; ) {
t[i] = (t[i] & 1) ? (t[i] >> 1) ^ 0x82f63b78 t[i] = (t[i] & 1) ? (t[i] >> 1) ^ 0x82f63b78
: (t[i] >> 1); : (t[i] >> 1);
} }
@ -104,7 +104,6 @@ namespace SK_OPTS_NS {
// Handle the bulk with a few data-parallel independent hashes, // Handle the bulk with a few data-parallel independent hashes,
// taking advantage of pipelining and superscalar execution. // taking advantage of pipelining and superscalar execution.
// TODO: four parallel hashes looks faster than three?
if (len >= 24) { if (len >= 24) {
uint32_t a = seed, uint32_t a = seed,
b = seed, b = seed,