ffmpeg/libavcodec/x86/utvideodsp.asm
Lynne bbe95f7353
x86: replace explicit REP_RETs with RETs
From x86inc:
> On AMD cpus <=K10, an ordinary ret is slow if it immediately follows either
> a branch or a branch target. So switch to a 2-byte form of ret in that case.
> We can automatically detect "follows a branch", but not a branch target.
> (SSSE3 is a sufficient condition to know that your cpu doesn't have this problem.)

x86inc can automatically determine whether to use REP_RET rather than
REP in most of these cases, so impact is minimal. Additionally, a few
REP_RETs were used unnecessary, despite the return being nowhere near a
branch.

The only CPUs affected were AMD K10s, made between 2007 and 2011, 16
years ago and 12 years ago, respectively.

In the future, everyone involved with x86inc should consider dropping
REP_RETs altogether.
2023-02-01 04:23:55 +01:00

138 lines
4.2 KiB
NASM

;******************************************************************************
;* SIMD-optimized UTVideo functions
;* Copyright (c) 2017 Paul B Mahol
;* Copyright (c) 2017 Jokyo Images
;*
;* This file is part of FFmpeg.
;*
;* FFmpeg is free software; you can redistribute it and/or
;* modify it under the terms of the GNU Lesser General Public
;* License as published by the Free Software Foundation; either
;* version 2.1 of the License, or (at your option) any later version.
;*
;* FFmpeg is distributed in the hope that it will be useful,
;* but WITHOUT ANY WARRANTY; without even the implied warranty of
;* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;* Lesser General Public License for more details.
;*
;* You should have received a copy of the GNU Lesser General Public
;* License along with FFmpeg; if not, write to the Free Software
;* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
;******************************************************************************
%include "libavutil/x86/x86util.asm"
SECTION_RODATA
cextern pb_80
cextern pw_512
cextern pw_1023
SECTION .text
;-------------------------------------------------------------------------------------------
; void restore_rgb_planes(uint8_t *src_r, uint8_t *src_g, uint8_t *src_b,
; ptrdiff_t linesize_r, ptrdiff_t linesize_g, ptrdiff_t linesize_b,
; int width, int height)
;-------------------------------------------------------------------------------------------
%macro RESTORE_RGB_PLANES 0
cglobal restore_rgb_planes, 7 + ARCH_X86_64, 7 + ARCH_X86_64 * 2, 4, src_r, src_g, src_b, linesize_r, linesize_g, linesize_b, w, h, x
movsxdifnidn wq, wd
add src_rq, wq
add src_gq, wq
add src_bq, wq
neg wq
%if ARCH_X86_64 == 0
mov wm, wq
DEFINE_ARGS src_r, src_g, src_b, linesize_r, linesize_g, linesize_b, x
%define wq r6m
%define hd r7mp
%endif
mova m3, [pb_80]
.nextrow:
mov xq, wq
.loop:
mova m0, [src_rq + xq]
mova m1, [src_gq + xq]
mova m2, [src_bq + xq]
psubb m1, m3
paddb m0, m1
paddb m2, m1
mova [src_rq+xq], m0
mova [src_bq+xq], m2
add xq, mmsize
jl .loop
add src_rq, linesize_rq
add src_gq, linesize_gq
add src_bq, linesize_bq
sub hd, 1
jg .nextrow
RET
%endmacro
INIT_XMM sse2
RESTORE_RGB_PLANES
%if HAVE_AVX2_EXTERNAL
INIT_YMM avx2
RESTORE_RGB_PLANES
%endif
;-------------------------------------------------------------------------------------------
; void restore_rgb_planes10(uint16_t *src_r, uint16_t *src_g, uint16_t *src_b,
; ptrdiff_t linesize_r, ptrdiff_t linesize_g, ptrdiff_t linesize_b,
; int width, int height)
;-------------------------------------------------------------------------------------------
%macro RESTORE_RGB_PLANES10 0
cglobal restore_rgb_planes10, 7 + ARCH_X86_64, 7 + ARCH_X86_64 * 2, 5, src_r, src_g, src_b, linesize_r, linesize_g, linesize_b, w, h, x
shl wd, 1
shl linesize_rq, 1
shl linesize_gq, 1
shl linesize_bq, 1
add src_rq, wq
add src_gq, wq
add src_bq, wq
mova m3, [pw_512]
mova m4, [pw_1023]
neg wq
%if ARCH_X86_64 == 0
mov wm, wq
DEFINE_ARGS src_r, src_g, src_b, linesize_r, linesize_g, linesize_b, x
%define wq r6m
%define hd r7mp
%endif
.nextrow:
mov xq, wq
.loop:
mova m0, [src_rq + xq]
mova m1, [src_gq + xq]
mova m2, [src_bq + xq]
psubw m1, m3
paddw m0, m1
paddw m2, m1
pand m0, m4
pand m2, m4
mova [src_rq+xq], m0
mova [src_bq+xq], m2
add xq, mmsize
jl .loop
add src_rq, linesize_rq
add src_gq, linesize_gq
add src_bq, linesize_bq
sub hd, 1
jg .nextrow
RET
%endmacro
INIT_XMM sse2
RESTORE_RGB_PLANES10
%if HAVE_AVX2_EXTERNAL
INIT_YMM avx2
RESTORE_RGB_PLANES10
%endif