huffyuvencdsp: Convert ff_diff_bytes_mmx to yasm

Heavily based upon ff_add_bytes by Christophe Gisquet.

Reviewed-by: James Almer <jamrial@gmail.com>
Signed-off-by: Timothy Gu <timothygu99@gmail.com>

3 files changed, 81 insertions, 30 deletions

diff --git a/libavcodec/x86/Makefile b/libavcodec/x86/Makefile
index 4591e4bc80..e1b1f0c61f 100644
--- a/libavcodec/x86/Makefile
+++ b/libavcodec/x86/Makefile
@@ -115,6 +115,7 @@ YASM-OBJS-$(CONFIG_H264QPEL)           += x86/h264_qpel_8bit.o          \
 YASM-OBJS-$(CONFIG_HPELDSP)            += x86/fpel.o                    \
                                           x86/hpeldsp.o
 YASM-OBJS-$(CONFIG_HUFFYUVDSP)         += x86/huffyuvdsp.o
+YASM-OBJS-$(CONFIG_HUFFYUVENCDSP)      += x86/huffyuvencdsp.o
 YASM-OBJS-$(CONFIG_IDCTDSP)            += x86/idctdsp.o
 YASM-OBJS-$(CONFIG_LLAUDDSP)           += x86/lossless_audiodsp.o
 YASM-OBJS-$(CONFIG_LLVIDDSP)           += x86/lossless_videodsp.o
diff --git a/libavcodec/x86/huffyuvencdsp.asm b/libavcodec/x86/huffyuvencdsp.asm
new file mode 100644
index 0000000000..e001906742
--- /dev/null
+++ b/libavcodec/x86/huffyuvencdsp.asm
@@ -0,0 +1,73 @@
+;************************************************************************
+;* SIMD-optimized HuffYUV encoding functions
+;* Copyright (c) 2000, 2001 Fabrice Bellard
+;* Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
+;*
+;* MMX optimization by Nick Kurshev <nickols_k@mail.ru>
+;* Conversion to NASM format by Tiancheng "Timothy" Gu <timothygu99@gmail.com>
+;*
+;* 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
+;* 51, Inc., Foundation Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+;******************************************************************************
+
+%include "libavutil/x86/x86util.asm"
+
+section .text
+
+INIT_MMX mmx
+; void ff_diff_bytes_mmx(uint8_t *dst, const uint8_t *src1, const uint8_t *src2,
+;                        intptr_t w);
+%if ARCH_X86_32
+cglobal diff_bytes, 3,5,2, dst, src1, src2
+%define wq r4q
+    DECLARE_REG_TMP 3
+    mov               wq, r3mp
+%else
+cglobal diff_bytes, 4,5,2, dst, src1, src2, w
+    DECLARE_REG_TMP 4
+%endif ; ARCH_X86_32
+%define i t0q
+    mov                i, wq
+    and                i, -2 * mmsize
+        jz  .setup_loop2
+    add             dstq, i
+    add            src1q, i
+    add            src2q, i
+    neg                i
+.loop:
+    mova              m0, [src1q + i]
+    mova              m1, [src1q + i + mmsize]
+    psubb             m0, [src2q + i]
+    psubb             m1, [src2q + i + mmsize]
+    mova          [dstq + i], m0
+    mova [mmsize + dstq + i], m1
+    add                i, 2 * mmsize
+        jl         .loop
+.setup_loop2:
+    and               wq, 2 * mmsize - 1
+        jz          .end
+    add             dstq, wq
+    add            src1q, wq
+    add            src2q, wq
+    neg               wq
+.loop2:
+    mov              t0b, [src1q + wq]
+    sub              t0b, [src2q + wq]
+    mov      [dstq + wq], t0b
+    inc               wq
+        jl        .loop2
+.end:
+    REP_RET
diff --git a/libavcodec/x86/huffyuvencdsp_mmx.c b/libavcodec/x86/huffyuvencdsp_mmx.c
index ee60f4c573..f28df05dba 100644
--- a/libavcodec/x86/huffyuvencdsp_mmx.c
+++ b/libavcodec/x86/huffyuvencdsp_mmx.c
@@ -29,33 +29,10 @@
 #include "libavcodec/huffyuvencdsp.h"
 #include "libavcodec/mathops.h"
 
-#if HAVE_INLINE_ASM
-
-static void diff_bytes_mmx(uint8_t *dst, const uint8_t *src1, const uint8_t *src2,
-                           intptr_t w)
-{
-    x86_reg i = 0;
-
-    if (w >= 16)
-    __asm__ volatile (
-        "1:                             \n\t"
-        "movq  (%2, %0), %%mm0          \n\t"
-        "movq  (%1, %0), %%mm1          \n\t"
-        "psubb %%mm0, %%mm1             \n\t"
-        "movq %%mm1, (%3, %0)           \n\t"
-        "movq 8(%2, %0), %%mm0          \n\t"
-        "movq 8(%1, %0), %%mm1          \n\t"
-        "psubb %%mm0, %%mm1             \n\t"
-        "movq %%mm1, 8(%3, %0)          \n\t"
-        "add $16, %0                    \n\t"
-        "cmp %4, %0                     \n\t"
-        " jb 1b                         \n\t"
-        : "+r" (i)
-        : "r" (src1), "r" (src2), "r" (dst), "r" ((x86_reg) w - 15));
+void ff_diff_bytes_mmx(uint8_t *dst, const uint8_t *src1, const uint8_t *src2,
+                       intptr_t w);
 
-    for (; i < w; i++)
-        dst[i + 0] = src1[i + 0] - src2[i + 0];
-}
+#if HAVE_INLINE_ASM
 
 static void sub_hfyu_median_pred_mmxext(uint8_t *dst, const uint8_t *src1,
                                         const uint8_t *src2, intptr_t w,
@@ -101,13 +78,13 @@ static void sub_hfyu_median_pred_mmxext(uint8_t *dst, const uint8_t *src1,
 
 av_cold void ff_huffyuvencdsp_init_x86(HuffYUVEncDSPContext *c)
 {
-#if HAVE_INLINE_ASM
-    int cpu_flags = av_get_cpu_flags();
+    av_unused int cpu_flags = av_get_cpu_flags();
 
-    if (INLINE_MMX(cpu_flags)) {
-        c->diff_bytes = diff_bytes_mmx;
+    if (EXTERNAL_MMX(cpu_flags)) {
+        c->diff_bytes = ff_diff_bytes_mmx;
     }
 
+#if HAVE_INLINE_ASM
     if (INLINE_MMXEXT(cpu_flags)) {
         c->sub_hfyu_median_pred = sub_hfyu_median_pred_mmxext;
     }