Re: [PATCH] ALSA: echoaudio: simplify get_audio_levels
From: Takashi Iwai
Date: Sun Dec 08 2019 - 03:48:21 EST
On Sat, 07 Dec 2019 23:49:53 +0100,
Olof Johansson wrote:
>
> The loop optimizer seems to go astray here, and produces some warnings
> that don't seem valid.
>
> Still, the code can be simplified -- just clear the whole array at the
> beginning, and fill in whatever values are valid on the platform.
>
> Warnings before this change (GCC 8.2.0 ARM allmodconfig):
>
> In file included from ../sound/pci/echoaudio/gina24.c:115:
> ../sound/pci/echoaudio/echoaudio.c: In function 'snd_echo_vumeters_get':
> ../sound/pci/echoaudio/echoaudio_dsp.c:647:9: warning: iteration 1073741824 invokes undefined behavior [-Waggressive-loop-optimizations]
> In file included from ../sound/pci/echoaudio/layla24.c:112:
> ../sound/pci/echoaudio/echoaudio.c: In function 'snd_echo_vumeters_get':
> ../sound/pci/echoaudio/echoaudio_dsp.c:658:9: warning: iteration 1073741824 invokes undefined behavior [-Waggressive-loop-optimizations]
> ../sound/pci/echoaudio/echoaudio_dsp.c:647:9: warning: iteration 1073741824 invokes undefined behavior [-Waggressive-loop-optimizations]
>
> Signed-off-by: Olof Johansson <olof@xxxxxxxxx>
Applied now, thanks.
Takashi