[FFmpeg-devel] [PATCH] avcodec: flac x86 asm fix
James Almer
jamrial at gmail.com
Mon Sep 5 14:19:29 EEST 2022
On 9/3/2022 6:45 PM, Paul B Mahol wrote:
> Patch attached.
[...]
> From 0f220489eb6402c6be3bc1d897c95fa9bc10431c Mon Sep 17 00:00:00 2001
> From: Paul B Mahol <onemda at gmail.com>
> Date: Sat, 3 Sep 2022 23:41:38 +0200
> Subject: [PATCH] avcodec/x86/flacdsp: fix bug in decorrelation
>
> Fixes #9297
>
> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
> libavcodec/x86/flacdsp.asm | 23 +++++++++++++++-----
> libavcodec/x86/flacdsp_init.c | 41 ++++++++++++++++++++++-------------
> 2 files changed, 44 insertions(+), 20 deletions(-)
>
> diff --git a/libavcodec/x86/flacdsp.asm b/libavcodec/x86/flacdsp.asm
> index 7138611526..6d755f4972 100644
> --- a/libavcodec/x86/flacdsp.asm
> +++ b/libavcodec/x86/flacdsp.asm
> @@ -23,6 +23,10 @@
>
> %include "libavutil/x86/x86util.asm"
>
> +SECTION_RODATA
> +
> +vector: db 0,1,4,5,8,9,12,13,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,0,1,4,5,8,9,12,13,
> +
> SECTION .text
>
> %macro PMACSDQL 5
> @@ -89,6 +93,9 @@ LPC_32 sse4
> ;----------------------------------------------------------------------------------
> %macro FLAC_DECORRELATE_16 3-4
> cglobal flac_decorrelate_%1_16, 2, 4, 4, out, in0, in1, len
> +%ifidn %1, indep2
> + VBROADCASTI128 m2, [vector]
You're loading 16 bytes, yet vector is 32 bytes. Are you sure this is
ok? The upper 16 bytes look different, which makes me think you meant to
use them.
> +%endif
> %if ARCH_X86_32
> mov lend, lenm
> %endif
> @@ -112,11 +119,17 @@ align 16
> %endif
> %ifnidn %1, indep2
> p%4d m2, m0, m1
> + packssdw m%2, m%2
> + packssdw m%3, m%3
> + punpcklwd m%2, m%3
> + psllw m%2, m3
> +%else
> + pslld m%2, m3
> + pslld m%3, m3
> + pshufb m%2, m%2, m2
> + pshufb m%3, m%3, m2
> + punpcklwd m%2, m%3
> %endif
> - packssdw m%2, m%2
> - packssdw m%3, m%3
> - punpcklwd m%2, m%3
> - psllw m%2, m3
> mova [outq + lenq], m%2
> add lenq, 16
> jl .loop
> @@ -292,7 +305,7 @@ align 16
> REP_RET
> %endmacro
>
> -INIT_XMM sse2
> +INIT_XMM ssse3
Why are you turning all the unrelated indep functions into ssse3 when
you only changed the FLAC_DECORRELATE_16 macro to fix the stereo 16bit
indep path?
And did you try using FLAC_DECORRELATE_INDEP for it instead? I did
mention below i purposely used a different macro for that specific
scenario (probably to save some instructions), so the fix could have
been using the proper indep macro.
> FLAC_DECORRELATE_16 indep2, 0, 1 ; Reuse stereo 16bits macro
> FLAC_DECORRELATE_INDEP 32, 2, 3, d
> FLAC_DECORRELATE_INDEP 16, 4, 3, w
> diff --git a/libavcodec/x86/flacdsp_init.c b/libavcodec/x86/flacdsp_init.c
> index 2deaf3117f..48e3e7c55c 100644
> --- a/libavcodec/x86/flacdsp_init.c
> +++ b/libavcodec/x86/flacdsp_init.c
> @@ -34,7 +34,9 @@ void ff_flac_decorrelate_ls_##fmt##_##opt(uint8_t **out, int32_t **in, int chann
> void ff_flac_decorrelate_rs_##fmt##_##opt(uint8_t **out, int32_t **in, int channels, \
> int len, int shift); \
> void ff_flac_decorrelate_ms_##fmt##_##opt(uint8_t **out, int32_t **in, int channels, \
> - int len, int shift); \
> + int len, int shift);
> +
> +#define DECORRELATE_IFUNCS(fmt, opt) \
> void ff_flac_decorrelate_indep2_##fmt##_##opt(uint8_t **out, int32_t **in, int channels, \
> int len, int shift); \
> void ff_flac_decorrelate_indep4_##fmt##_##opt(uint8_t **out, int32_t **in, int channels, \
> @@ -48,6 +50,10 @@ DECORRELATE_FUNCS(16, sse2);
> DECORRELATE_FUNCS(16, avx);
> DECORRELATE_FUNCS(32, sse2);
> DECORRELATE_FUNCS(32, avx);
> +DECORRELATE_IFUNCS(16, ssse3);
> +DECORRELATE_IFUNCS(16, avx);
> +DECORRELATE_IFUNCS(32, ssse3);
> +DECORRELATE_IFUNCS(32, avx);
>
> av_cold void ff_flacdsp_init_x86(FLACDSPContext *c, enum AVSampleFormat fmt, int channels)
> {
> @@ -55,30 +61,35 @@ av_cold void ff_flacdsp_init_x86(FLACDSPContext *c, enum AVSampleFormat fmt, int
> int cpu_flags = av_get_cpu_flags();
>
> if (EXTERNAL_SSE2(cpu_flags)) {
> + if (fmt == AV_SAMPLE_FMT_S16) {
> + c->decorrelate[1] = ff_flac_decorrelate_ls_16_sse2;
> + c->decorrelate[2] = ff_flac_decorrelate_rs_16_sse2;
> + c->decorrelate[3] = ff_flac_decorrelate_ms_16_sse2;
> + } else if (fmt == AV_SAMPLE_FMT_S32) {
> + c->decorrelate[1] = ff_flac_decorrelate_ls_32_sse2;
> + c->decorrelate[2] = ff_flac_decorrelate_rs_32_sse2;
> + c->decorrelate[3] = ff_flac_decorrelate_ms_32_sse2;
> + }
> + }
> + if (EXTERNAL_SSSE3(cpu_flags)) {
> if (fmt == AV_SAMPLE_FMT_S16) {
> if (channels == 2)
> - c->decorrelate[0] = ff_flac_decorrelate_indep2_16_sse2;
> + c->decorrelate[0] = ff_flac_decorrelate_indep2_16_ssse3;
> else if (channels == 4)
> - c->decorrelate[0] = ff_flac_decorrelate_indep4_16_sse2;
> + c->decorrelate[0] = ff_flac_decorrelate_indep4_16_ssse3;
> else if (channels == 6)
> - c->decorrelate[0] = ff_flac_decorrelate_indep6_16_sse2;
> + c->decorrelate[0] = ff_flac_decorrelate_indep6_16_ssse3;
> else if (ARCH_X86_64 && channels == 8)
> - c->decorrelate[0] = ff_flac_decorrelate_indep8_16_sse2;
> - c->decorrelate[1] = ff_flac_decorrelate_ls_16_sse2;
> - c->decorrelate[2] = ff_flac_decorrelate_rs_16_sse2;
> - c->decorrelate[3] = ff_flac_decorrelate_ms_16_sse2;
> + c->decorrelate[0] = ff_flac_decorrelate_indep8_16_ssse3;
> } else if (fmt == AV_SAMPLE_FMT_S32) {
> if (channels == 2)
> - c->decorrelate[0] = ff_flac_decorrelate_indep2_32_sse2;
> + c->decorrelate[0] = ff_flac_decorrelate_indep2_32_ssse3;
> else if (channels == 4)
> - c->decorrelate[0] = ff_flac_decorrelate_indep4_32_sse2;
> + c->decorrelate[0] = ff_flac_decorrelate_indep4_32_ssse3;
> else if (channels == 6)
> - c->decorrelate[0] = ff_flac_decorrelate_indep6_32_sse2;
> + c->decorrelate[0] = ff_flac_decorrelate_indep6_32_ssse3;
> else if (ARCH_X86_64 && channels == 8)
> - c->decorrelate[0] = ff_flac_decorrelate_indep8_32_sse2;
> - c->decorrelate[1] = ff_flac_decorrelate_ls_32_sse2;
> - c->decorrelate[2] = ff_flac_decorrelate_rs_32_sse2;
> - c->decorrelate[3] = ff_flac_decorrelate_ms_32_sse2;
> + c->decorrelate[0] = ff_flac_decorrelate_indep8_32_ssse3;
> }
> }
> if (EXTERNAL_SSE4(cpu_flags)) {
> --
> 2.37.2
>
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