shithub: opus

Download patch

ref: 32f66877d438744c08476c1e7d04623cb5cffcea
parent: 247ea8367395a95e5be2a7a9c5dfb8025a3f367e
author: Siarhei Volkau <lis8215@gmail.com>
date: Tue Sep 2 18:46:04 EDT 2025

opus_decode24: prevent aliasing pcm and st->channels

Both GCC and clang think that pcm and st->channels might alias
thus opus_decode24 is doing extra load+multiplication on each sample.
Moreover, aliasing prevents autovectorization of that loop.

Signed-off-by: Siarhei Volkau <lis8215@gmail.com>
Signed-off-by: Jean-Marc Valin <jmvalin@jmvalin.ca>

--- a/src/opus_decoder.c

+++ b/src/opus_decoder.c

@@ -931,7 +931,8 @@

        ret = opus_decode_native(st, data, len, out, frame_size, decode_fec, 0, NULL, 0, NULL, 0);

        if (ret > 0)

        {

-          for (i=0;i<ret*st->channels;i++)

+          nb_samples = ret*st->channels;

+          for (i=0;i<nb_samples;i++)

              pcm[i] = RES2INT24(out[i]);

        }

        RESTORE_STACK;

-- 

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