From: Jaroslav Kysela <perex@perex.cz>
Date: Mon, 5 Feb 2018 13:59:12 +0000 (+0100)
Subject: pcm: another fix for the snd_pcm_area_silence() fast path
X-Git-Tag: v1.1.6~14
X-Git-Url: https://git.alsa-project.org/?a=commitdiff_plain;h=af531606b73634b56ec0ec73fbea8297a7752172;p=alsa-lib.git

pcm: another fix for the snd_pcm_area_silence() fast path

The 64-bit fast path can be used only in limited conditions:

- destination must be aligned to 64-bit (CPU aligned access)
- step must be equal to width
- physical with must be different than 24 (cannot be multiplied to 64)

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---

diff --git a/src/pcm/pcm.c b/src/pcm/pcm.c
index 86250970..1be38339 100644
--- a/src/pcm/pcm.c
+++ b/src/pcm/pcm.c
@@ -2951,7 +2951,9 @@ int snd_pcm_area_silence(const snd_pcm_channel_area_t *dst_area, snd_pcm_uframes
          * Iterate copying silent sample for sample data aligned to 64 bit.
          * This is a fast path.
          */
-        if (dst_area->step == (unsigned int) width && (64 % width) == 0) {
+        if (dst_area->step == (unsigned int) width &&
+            width != 24 &&
+            ((intptr_t)dst & 7) == 0) {
 		unsigned int dwords = samples * width / 64;
 		uint64_t *dstp = (uint64_t *)dst;
 		samples -= dwords * 64 / width;