[FFmpeg-devel] [PATCH] lavc/x86/videodsp: Drop MMX usage
Andreas Rheinhardt
andreas.rheinhardt at outlook.com
Fri Nov 15 22:55:53 EET 2024
Frank Plowman:
> Remove the MMX versions of these functions and modify the SSE
> implementations to avoid using MMX registers.
>
> Signed-off-by: Frank Plowman <post at frankplowman.com>
> ---
> This wasn't wholly straightforward as the existing SSE implementation did
> not only use SSE but rather a blend of SSE and MMX. I would appreciate
> some review, as I am not particularly familiar with x86 assembly. Of
> particular interest are the changes to {READ,WRITE}_NUM_BYTES. The new
> implementation does not make economic use of the XMM registers like the
> old one did, but it still does not exhaust them -- was this more of a
> concern when this was originally written?
> ---
> libavcodec/x86/videodsp.asm | 63 ++++++----------------
> libavcodec/x86/videodsp_init.c | 99 +++++++++++++++++-----------------
> 2 files changed, 65 insertions(+), 97 deletions(-)
>
> diff --git a/libavcodec/x86/videodsp.asm b/libavcodec/x86/videodsp.asm
> index 3cc07878d3..20dcd3e2b9 100644
> --- a/libavcodec/x86/videodsp.asm
> +++ b/libavcodec/x86/videodsp.asm
> @@ -123,54 +123,43 @@ hvar_fn
> ; - if (%2 & 8) fills 8 bytes into xmm$next
> ; - if (%2 & 4) fills 4 bytes into xmm$next
> ; - if (%2 & 3) fills 1, 2 or 4 bytes in eax
> -; on mmx, - fills mm0-7 for consecutive sets of 8 pixels
> -; - if (%2 & 4) fills 4 bytes into mm$next
> -; - if (%2 & 3) fills 1, 2 or 4 bytes in eax
> ; writing data out is in the same way
> %macro READ_NUM_BYTES 2
> %assign %%off 0 ; offset in source buffer
> -%assign %%mmx_idx 0 ; mmx register index
> %assign %%xmm_idx 0 ; xmm register index
>
> %rep %2/mmsize
> -%if mmsize == 16
> movu xmm %+ %%xmm_idx, [srcq+%%off]
> %assign %%xmm_idx %%xmm_idx+1
> -%else ; mmx
> - movu mm %+ %%mmx_idx, [srcq+%%off]
> -%assign %%mmx_idx %%mmx_idx+1
> -%endif
> %assign %%off %%off+mmsize
> %endrep ; %2/mmsize
>
> -%if mmsize == 16
> %if (%2-%%off) >= 8
> %if %2 > 16 && (%2-%%off) > 8
> movu xmm %+ %%xmm_idx, [srcq+%2-16]
> %assign %%xmm_idx %%xmm_idx+1
> %assign %%off %2
> %else
> - movq mm %+ %%mmx_idx, [srcq+%%off]
> -%assign %%mmx_idx %%mmx_idx+1
> + movq xmm %+ %%xmm_idx, [srcq+%%off]
> +%assign %%xmm_idx %%xmm_idx+1
> %assign %%off %%off+8
> %endif
> %endif ; (%2-%%off) >= 8
> -%endif
>
> %if (%2-%%off) >= 4
> %if %2 > 8 && (%2-%%off) > 4
> - movq mm %+ %%mmx_idx, [srcq+%2-8]
> + movq xmm %+ %%xmm_idx, [srcq+%2-8]
> %assign %%off %2
> %else
> - movd mm %+ %%mmx_idx, [srcq+%%off]
> + movd xmm %+ %%xmm_idx, [srcq+%%off]
> %assign %%off %%off+4
> %endif
> -%assign %%mmx_idx %%mmx_idx+1
> +%assign %%xmm_idx %%xmm_idx+1
> %endif ; (%2-%%off) >= 4
>
> %if (%2-%%off) >= 1
> %if %2 >= 4
> - movd mm %+ %%mmx_idx, [srcq+%2-4]
> + movd xmm %+ %%xmm_idx, [srcq+%2-4]
> %elif (%2-%%off) == 1
> mov valb, [srcq+%2-1]
> %elif (%2-%%off) == 2
> @@ -185,48 +174,40 @@ hvar_fn
>
> %macro WRITE_NUM_BYTES 2
> %assign %%off 0 ; offset in destination buffer
> -%assign %%mmx_idx 0 ; mmx register index
> %assign %%xmm_idx 0 ; xmm register index
>
> %rep %2/mmsize
> -%if mmsize == 16
> movu [dstq+%%off], xmm %+ %%xmm_idx
> %assign %%xmm_idx %%xmm_idx+1
> -%else ; mmx
> - movu [dstq+%%off], mm %+ %%mmx_idx
> -%assign %%mmx_idx %%mmx_idx+1
> -%endif
> %assign %%off %%off+mmsize
> %endrep ; %2/mmsize
>
> -%if mmsize == 16
> %if (%2-%%off) >= 8
> %if %2 > 16 && (%2-%%off) > 8
> movu [dstq+%2-16], xmm %+ %%xmm_idx
> %assign %%xmm_idx %%xmm_idx+1
> %assign %%off %2
> %else
> - movq [dstq+%%off], mm %+ %%mmx_idx
> -%assign %%mmx_idx %%mmx_idx+1
> + movq [dstq+%%off], xmm %+ %%xmm_idx
> +%assign %%xmm_idx %%xmm_idx+1
> %assign %%off %%off+8
> %endif
> %endif ; (%2-%%off) >= 8
> -%endif
>
> %if (%2-%%off) >= 4
> %if %2 > 8 && (%2-%%off) > 4
> - movq [dstq+%2-8], mm %+ %%mmx_idx
> + movq [dstq+%2-8], xmm %+ %%xmm_idx
> %assign %%off %2
> %else
> - movd [dstq+%%off], mm %+ %%mmx_idx
> + movd [dstq+%%off], xmm %+ %%xmm_idx
> %assign %%off %%off+4
> %endif
> -%assign %%mmx_idx %%mmx_idx+1
> +%assign %%xmm_idx %%xmm_idx+1
> %endif ; (%2-%%off) >= 4
>
> %if (%2-%%off) >= 1
> %if %2 >= 4
> - movd [dstq+%2-4], mm %+ %%mmx_idx
> + movd [dstq+%2-4], xmm %+ %%xmm_idx
> %elif (%2-%%off) == 1
> mov [dstq+%2-1], valb
> %elif (%2-%%off) == 2
> @@ -318,11 +299,8 @@ cglobal emu_edge_vfix %+ %%n, 1, 5, 1, dst, src, start_y, end_y, bh
> %endrep ; 1+%2-%1
> %endmacro ; VERTICAL_EXTEND
>
> -INIT_MMX mmx
> -VERTICAL_EXTEND 1, 15
> -
> -INIT_XMM sse
> -VERTICAL_EXTEND 16, 22
> +INIT_XMM sse2
> +VERTICAL_EXTEND 1, 22
>
> ; left/right (horizontal) fast extend functions
> ; these are essentially identical to the vertical extend ones above,
> @@ -337,11 +315,7 @@ VERTICAL_EXTEND 16, 22
> imul vald, 0x01010101
> %if %1 >= 8
> movd m0, vald
> -%if mmsize == 16
> pshufd m0, m0, q0000
> -%else
> - punpckldq m0, m0
> -%endif ; mmsize == 16
> %endif ; %1 > 16
> %endif ; avx2
> %endmacro ; READ_V_PIXEL
> @@ -356,7 +330,6 @@ VERTICAL_EXTEND 16, 22
> %assign %%off %%off+mmsize
> %endrep ; %1/mmsize
>
> -%if mmsize == 16
> %if %1-%%off >= 8
> %if %1 > 16 && %1-%%off > 8
> movu [%2+%1-16], m0
> @@ -366,7 +339,6 @@ VERTICAL_EXTEND 16, 22
> %assign %%off %%off+8
> %endif
> %endif ; %1-%%off >= 8
> -%endif ; mmsize == 16
>
> %if %1-%%off >= 4
> %if %1 > 8 && %1-%%off > 4
> @@ -415,18 +387,15 @@ cglobal emu_edge_hfix %+ %%n, 4, 5, 1, dst, dst_stride, start_x, bh, val
> %endrep ; 1+(%2-%1)/2
> %endmacro ; H_EXTEND
>
> -INIT_MMX mmx
> -H_EXTEND 2, 14
> -
> INIT_XMM sse2
> -H_EXTEND 16, 22
> +H_EXTEND 2, 22
>
> %if HAVE_AVX2_EXTERNAL
> INIT_XMM avx2
> H_EXTEND 8, 22
> %endif
>
> -INIT_MMX mmxext
> +INIT_XMM sse2
> cglobal prefetch, 3, 3, 0, buf, stride, h
> .loop:
> prefetcht0 [bufq]
> diff --git a/libavcodec/x86/videodsp_init.c b/libavcodec/x86/videodsp_init.c
> index ae9db95624..376eec9c23 100644
> --- a/libavcodec/x86/videodsp_init.c
> +++ b/libavcodec/x86/videodsp_init.c
> @@ -37,37 +37,37 @@ typedef void emu_edge_vvar_func(uint8_t *dst, x86_reg dst_stride,
> x86_reg start_y, x86_reg end_y, x86_reg bh,
> x86_reg w);
>
> -extern emu_edge_vfix_func ff_emu_edge_vfix1_mmx;
> -extern emu_edge_vfix_func ff_emu_edge_vfix2_mmx;
> -extern emu_edge_vfix_func ff_emu_edge_vfix3_mmx;
> -extern emu_edge_vfix_func ff_emu_edge_vfix4_mmx;
> -extern emu_edge_vfix_func ff_emu_edge_vfix5_mmx;
> -extern emu_edge_vfix_func ff_emu_edge_vfix6_mmx;
> -extern emu_edge_vfix_func ff_emu_edge_vfix7_mmx;
> -extern emu_edge_vfix_func ff_emu_edge_vfix8_mmx;
> -extern emu_edge_vfix_func ff_emu_edge_vfix9_mmx;
> -extern emu_edge_vfix_func ff_emu_edge_vfix10_mmx;
> -extern emu_edge_vfix_func ff_emu_edge_vfix11_mmx;
> -extern emu_edge_vfix_func ff_emu_edge_vfix12_mmx;
> -extern emu_edge_vfix_func ff_emu_edge_vfix13_mmx;
> -extern emu_edge_vfix_func ff_emu_edge_vfix14_mmx;
> -extern emu_edge_vfix_func ff_emu_edge_vfix15_mmx;
> -extern emu_edge_vfix_func ff_emu_edge_vfix16_sse;
> -extern emu_edge_vfix_func ff_emu_edge_vfix17_sse;
> -extern emu_edge_vfix_func ff_emu_edge_vfix18_sse;
> -extern emu_edge_vfix_func ff_emu_edge_vfix19_sse;
> -extern emu_edge_vfix_func ff_emu_edge_vfix20_sse;
> -extern emu_edge_vfix_func ff_emu_edge_vfix21_sse;
> -extern emu_edge_vfix_func ff_emu_edge_vfix22_sse;
> -static emu_edge_vfix_func * const vfixtbl_sse[22] = {
> - ff_emu_edge_vfix1_mmx, ff_emu_edge_vfix2_mmx, ff_emu_edge_vfix3_mmx,
> - ff_emu_edge_vfix4_mmx, ff_emu_edge_vfix5_mmx, ff_emu_edge_vfix6_mmx,
> - ff_emu_edge_vfix7_mmx, ff_emu_edge_vfix8_mmx, ff_emu_edge_vfix9_mmx,
> - ff_emu_edge_vfix10_mmx, ff_emu_edge_vfix11_mmx, ff_emu_edge_vfix12_mmx,
> - ff_emu_edge_vfix13_mmx, ff_emu_edge_vfix14_mmx, ff_emu_edge_vfix15_mmx,
> - ff_emu_edge_vfix16_sse, ff_emu_edge_vfix17_sse, ff_emu_edge_vfix18_sse,
> - ff_emu_edge_vfix19_sse, ff_emu_edge_vfix20_sse, ff_emu_edge_vfix21_sse,
> - ff_emu_edge_vfix22_sse
> +extern emu_edge_vfix_func ff_emu_edge_vfix1_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix2_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix3_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix4_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix5_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix6_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix7_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix8_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix9_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix10_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix11_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix12_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix13_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix14_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix15_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix16_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix17_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix18_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix19_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix20_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix21_sse2;
> +extern emu_edge_vfix_func ff_emu_edge_vfix22_sse2;
> +static emu_edge_vfix_func * const vfixtbl_sse2[22] = {
> + ff_emu_edge_vfix1_sse2, ff_emu_edge_vfix2_sse2, ff_emu_edge_vfix3_sse2,
> + ff_emu_edge_vfix4_sse2, ff_emu_edge_vfix5_sse2, ff_emu_edge_vfix6_sse2,
> + ff_emu_edge_vfix7_sse2, ff_emu_edge_vfix8_sse2, ff_emu_edge_vfix9_sse2,
> + ff_emu_edge_vfix10_sse2, ff_emu_edge_vfix11_sse2, ff_emu_edge_vfix12_sse2,
> + ff_emu_edge_vfix13_sse2, ff_emu_edge_vfix14_sse2, ff_emu_edge_vfix15_sse2,
> + ff_emu_edge_vfix16_sse2, ff_emu_edge_vfix17_sse2, ff_emu_edge_vfix18_sse2,
> + ff_emu_edge_vfix19_sse2, ff_emu_edge_vfix20_sse2, ff_emu_edge_vfix21_sse2,
> + ff_emu_edge_vfix22_sse2
> };
> extern emu_edge_vvar_func ff_emu_edge_vvar_sse;
>
> @@ -76,21 +76,21 @@ typedef void emu_edge_hfix_func(uint8_t *dst, x86_reg dst_stride,
> typedef void emu_edge_hvar_func(uint8_t *dst, x86_reg dst_stride,
> x86_reg start_x, x86_reg n_words, x86_reg bh);
>
> -extern emu_edge_hfix_func ff_emu_edge_hfix2_mmx;
> -extern emu_edge_hfix_func ff_emu_edge_hfix4_mmx;
> -extern emu_edge_hfix_func ff_emu_edge_hfix6_mmx;
> -extern emu_edge_hfix_func ff_emu_edge_hfix8_mmx;
> -extern emu_edge_hfix_func ff_emu_edge_hfix10_mmx;
> -extern emu_edge_hfix_func ff_emu_edge_hfix12_mmx;
> -extern emu_edge_hfix_func ff_emu_edge_hfix14_mmx;
> +extern emu_edge_hfix_func ff_emu_edge_hfix2_sse2;
> +extern emu_edge_hfix_func ff_emu_edge_hfix4_sse2;
> +extern emu_edge_hfix_func ff_emu_edge_hfix6_sse2;
> +extern emu_edge_hfix_func ff_emu_edge_hfix8_sse2;
> +extern emu_edge_hfix_func ff_emu_edge_hfix10_sse2;
> +extern emu_edge_hfix_func ff_emu_edge_hfix12_sse2;
> +extern emu_edge_hfix_func ff_emu_edge_hfix14_sse2;
> extern emu_edge_hfix_func ff_emu_edge_hfix16_sse2;
> extern emu_edge_hfix_func ff_emu_edge_hfix18_sse2;
> extern emu_edge_hfix_func ff_emu_edge_hfix20_sse2;
> extern emu_edge_hfix_func ff_emu_edge_hfix22_sse2;
> static emu_edge_hfix_func * const hfixtbl_sse2[11] = {
> - ff_emu_edge_hfix2_mmx, ff_emu_edge_hfix4_mmx, ff_emu_edge_hfix6_mmx,
> - ff_emu_edge_hfix8_mmx, ff_emu_edge_hfix10_mmx, ff_emu_edge_hfix12_mmx,
> - ff_emu_edge_hfix14_mmx, ff_emu_edge_hfix16_sse2, ff_emu_edge_hfix18_sse2,
> + ff_emu_edge_hfix2_sse2, ff_emu_edge_hfix4_sse2, ff_emu_edge_hfix6_sse2,
> + ff_emu_edge_hfix8_sse2, ff_emu_edge_hfix10_sse2, ff_emu_edge_hfix12_sse2,
> + ff_emu_edge_hfix14_sse2, ff_emu_edge_hfix16_sse2, ff_emu_edge_hfix18_sse2,
> ff_emu_edge_hfix20_sse2, ff_emu_edge_hfix22_sse2
> };
> extern emu_edge_hvar_func ff_emu_edge_hvar_sse2;
> @@ -104,7 +104,7 @@ extern emu_edge_hfix_func ff_emu_edge_hfix18_avx2;
> extern emu_edge_hfix_func ff_emu_edge_hfix20_avx2;
> extern emu_edge_hfix_func ff_emu_edge_hfix22_avx2;
> static emu_edge_hfix_func * const hfixtbl_avx2[11] = {
> - ff_emu_edge_hfix2_mmx, ff_emu_edge_hfix4_mmx, ff_emu_edge_hfix6_mmx,
> + ff_emu_edge_hfix2_sse2, ff_emu_edge_hfix4_sse2, ff_emu_edge_hfix6_sse2,
> ff_emu_edge_hfix8_avx2, ff_emu_edge_hfix10_avx2, ff_emu_edge_hfix12_avx2,
> ff_emu_edge_hfix14_avx2, ff_emu_edge_hfix16_avx2, ff_emu_edge_hfix18_avx2,
> ff_emu_edge_hfix20_avx2, ff_emu_edge_hfix22_avx2
> @@ -196,7 +196,7 @@ static av_noinline void emulated_edge_mc_sse2(uint8_t *buf, const uint8_t *src,
> int h)
> {
> emulated_edge_mc(buf, src, buf_stride, src_stride, block_w, block_h,
> - src_x, src_y, w, h, vfixtbl_sse, &ff_emu_edge_vvar_sse,
> + src_x, src_y, w, h, vfixtbl_sse2, &ff_emu_edge_vvar_sse,
> hfixtbl_sse2, &ff_emu_edge_hvar_sse2);
> }
>
> @@ -209,24 +209,23 @@ static av_noinline void emulated_edge_mc_avx2(uint8_t *buf, const uint8_t *src,
> int h)
> {
> emulated_edge_mc(buf, src, buf_stride, src_stride, block_w, block_h,
> - src_x, src_y, w, h, vfixtbl_sse, &ff_emu_edge_vvar_sse,
> + src_x, src_y, w, h, vfixtbl_sse2, &ff_emu_edge_vvar_sse,
> hfixtbl_avx2, &ff_emu_edge_hvar_avx2);
> }
> #endif /* HAVE_AVX2_EXTERNAL */
> #endif /* HAVE_X86ASM */
>
> -void ff_prefetch_mmxext(const uint8_t *buf, ptrdiff_t stride, int h);
> +void ff_prefetch_sse2(const uint8_t *buf, ptrdiff_t stride, int h);
>
> av_cold void ff_videodsp_init_x86(VideoDSPContext *ctx, int bpc)
> {
> #if HAVE_X86ASM
> int cpu_flags = av_get_cpu_flags();
>
> - if (EXTERNAL_MMXEXT(cpu_flags)) {
> - ctx->prefetch = ff_prefetch_mmxext;
> - }
> - if (EXTERNAL_SSE2(cpu_flags) && bpc <= 8) {
> - ctx->emulated_edge_mc = emulated_edge_mc_sse2;
> + if (EXTERNAL_SSE2(cpu_flags)) {
> + ctx->prefetch = ff_prefetch_sse2;
> + if (bpc <= 8)
> + ctx->emulated_edge_mc = emulated_edge_mc_sse2;
> }
> #if HAVE_AVX2_EXTERNAL
> if (EXTERNAL_AVX2(cpu_flags) && bpc <= 8) {
Why did you change prefetch to declare an SSE2 requirement?
- Andreas
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