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| author | Přemysl Eric Janouch <p@janouch.name> | 2021-11-15 08:20:05 +0100 |
|---|---|---|
| committer | Přemysl Eric Janouch <p@janouch.name> | 2021-11-15 09:47:00 +0100 |
| commit | 6f86911df69bcfcd69d90feef43fef3450fc36e5 (patch) | |
| tree | a6101eefa024c743f763436cbeb5592fd2fb52e6 | |
| parent | 37adaac965d2dc7cbb28c1068c382521a30092b6 (diff) | |
| download | fiv-6f86911df69bcfcd69d90feef43fef3450fc36e5.tar.gz fiv-6f86911df69bcfcd69d90feef43fef3450fc36e5.tar.xz fiv-6f86911df69bcfcd69d90feef43fef3450fc36e5.zip | |
Slightly optimize thumbnail loading
Now it translates to just x86 bswap and ror.
| -rw-r--r-- | fastiv-io.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/fastiv-io.c b/fastiv-io.c index f5b3b1a..64bbb3c 100644 --- a/fastiv-io.c +++ b/fastiv-io.c @@ -710,7 +710,7 @@ read_spng_thumbnail( ihdr.color_type == SPNG_COLOR_TYPE_TRUECOLOR_ALPHA || !spng_get_trns(ctx, &trns)) { for (size_t i = size / sizeof *output; i--; ) { - uint8_t *unit = (uint8_t *) &data[i], + const uint8_t *unit = (const uint8_t *) &data[i], a = unit[3], b = unit[2] * a / 255, g = unit[1] * a / 255, @@ -719,12 +719,8 @@ read_spng_thumbnail( } } else { for (size_t i = size / sizeof *output; i--; ) { - uint8_t *unit = (uint8_t *) &data[i], - a = unit[3], - b = unit[2], - g = unit[1], - r = unit[0]; - output[i] = a << 24 | r << 16 | g << 8 | b; + uint32_t x = g_ntohl(data[i]); + output[i] = x << 24 | x >> 8; } } |