[FFmpeg-cvslog] avcodec: [loongson] optimize get_cabac_inline.
Shiyou Yin
git at videolan.org
Wed Sep 19 19:52:50 EEST 2018
ffmpeg | branch: master | Shiyou Yin <yinshiyou-hf at loongson.cn> | Tue Sep 18 10:59:41 2018 +0800| [ba175578d14e6c8f5df8b63bdbb3bcac86dcdc30] | committer: Michael Niedermayer
avcodec: [loongson] optimize get_cabac_inline.
This optimization improved h264 decoding performance about 4%(from 74fps to 77fps, tested on loongson 3A3000).
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ba175578d14e6c8f5df8b63bdbb3bcac86dcdc30
---
libavcodec/cabac_functions.h | 3 ++
libavcodec/mips/cabac.h | 119 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 122 insertions(+)
diff --git a/libavcodec/cabac_functions.h b/libavcodec/cabac_functions.h
index fe72a826cf..bb2b4210b7 100644
--- a/libavcodec/cabac_functions.h
+++ b/libavcodec/cabac_functions.h
@@ -45,6 +45,9 @@
#if ARCH_X86
# include "x86/cabac.h"
#endif
+#if ARCH_MIPS
+# include "mips/cabac.h"
+#endif
static const uint8_t * const ff_h264_norm_shift = ff_h264_cabac_tables + H264_NORM_SHIFT_OFFSET;
static const uint8_t * const ff_h264_lps_range = ff_h264_cabac_tables + H264_LPS_RANGE_OFFSET;
diff --git a/libavcodec/mips/cabac.h b/libavcodec/mips/cabac.h
new file mode 100644
index 0000000000..82cee29d73
--- /dev/null
+++ b/libavcodec/mips/cabac.h
@@ -0,0 +1,119 @@
+/*
+ * Loongson SIMD optimized h264chroma
+ *
+ * Copyright (c) 2018 Loongson Technology Corporation Limited
+ * Copyright (c) 2018 Shiyou Yin <yinshiyou-hf at loongson.cn>
+ *
+ * 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
+ */
+
+#ifndef AVCODEC_MIPS_CABAC_H
+#define AVCODEC_MIPS_CABAC_H
+
+#include "libavcodec/cabac.h"
+#include "libavutil/mips/mmiutils.h"
+#include "config.h"
+
+#define get_cabac_inline get_cabac_inline_mips
+static av_always_inline int get_cabac_inline(CABACContext *c,
+ uint8_t * const state){
+ mips_reg tmp0, tmp1, tmp2, bit;
+
+ __asm__ volatile (
+ "lbu %[bit], 0(%[state]) \n\t"
+ "and %[tmp0], %[c_range], 0xC0 \n\t"
+ PTR_ADDU "%[tmp0], %[tmp0], %[tmp0] \n\t"
+ PTR_ADDU "%[tmp0], %[tmp0], %[tables] \n\t"
+ PTR_ADDU "%[tmp0], %[tmp0], %[bit] \n\t"
+ /* tmp1: RangeLPS */
+ "lbu %[tmp1], %[lps_off](%[tmp0]) \n\t"
+
+ PTR_SUBU "%[c_range], %[c_range], %[tmp1] \n\t"
+ PTR_SLL "%[tmp0], %[c_range], 0x11 \n\t"
+ PTR_SUBU "%[tmp0], %[tmp0], %[c_low] \n\t"
+
+ /* tmp2: lps_mask */
+ PTR_SRA "%[tmp2], %[tmp0], 0x1F \n\t"
+ /* If tmp0 < 0, lps_mask == 0xffffffff*/
+ /* If tmp0 >= 0, lps_mask == 0x00000000*/
+ "beqz %[tmp2], 1f \n\t"
+ PTR_SLL "%[tmp0], %[c_range], 0x11 \n\t"
+ PTR_SUBU "%[c_low], %[c_low], %[tmp0] \n\t"
+ PTR_SUBU "%[tmp0], %[tmp1], %[c_range] \n\t"
+ PTR_ADDU "%[c_range], %[c_range], %[tmp0] \n\t"
+ "xor %[bit], %[bit], %[tmp2] \n\t"
+
+ "1: \n\t"
+ /* tmp1: *state */
+ PTR_ADDU "%[tmp0], %[tables], %[bit] \n\t"
+ "lbu %[tmp1], %[mlps_off](%[tmp0]) \n\t"
+ /* tmp2: lps_mask */
+ PTR_ADDU "%[tmp0], %[tables], %[c_range] \n\t"
+ "lbu %[tmp2], %[norm_off](%[tmp0]) \n\t"
+
+ "sb %[tmp1], 0(%[state]) \n\t"
+ "and %[bit], %[bit], 0x01 \n\t"
+ PTR_SLL "%[c_range], %[c_range], %[tmp2] \n\t"
+ PTR_SLL "%[c_low], %[c_low], %[tmp2] \n\t"
+
+ "and %[tmp0], %[c_low], %[cabac_mask] \n\t"
+ "bnez %[tmp0], 1f \n\t"
+ PTR_ADDI "%[tmp0], %[c_low], -0X01 \n\t"
+ "xor %[tmp0], %[c_low], %[tmp0] \n\t"
+ PTR_SRA "%[tmp0], %[tmp0], 0x0f \n\t"
+ PTR_ADDU "%[tmp0], %[tmp0], %[tables] \n\t"
+ "lbu %[tmp2], %[norm_off](%[tmp0]) \n\t"
+#if CABAC_BITS == 16
+ "lbu %[tmp0], 0(%[c_bytestream]) \n\t"
+ "lbu %[tmp1], 1(%[c_bytestream]) \n\t"
+ PTR_SLL "%[tmp0], %[tmp0], 0x09 \n\t"
+ PTR_SLL "%[tmp1], %[tmp1], 0x01 \n\t"
+ PTR_ADDU "%[tmp0], %[tmp0], %[tmp1] \n\t"
+#else
+ "lbu %[tmp0], 0(%[c_bytestream]) \n\t"
+ PTR_SLL "%[tmp0], %[tmp0], 0x01 \n\t"
+#endif
+ PTR_SUBU "%[tmp0], %[tmp0], %[cabac_mask] \n\t"
+
+ "li %[tmp1], 0x07 \n\t"
+ PTR_SUBU "%[tmp1], %[tmp1], %[tmp2] \n\t"
+ PTR_SLL "%[tmp0], %[tmp0], %[tmp1] \n\t"
+ PTR_ADDU "%[c_low], %[c_low], %[tmp0] \n\t"
+
+#if !UNCHECKED_BITSTREAM_READER
+ "bge %[c_bytestream], %[c_bytestream_end], 1f \n\t"
+#endif
+ PTR_ADDIU "%[c_bytestream], %[c_bytestream], 0X02 \n\t"
+ "1: \n\t"
+ : [bit]"=&r"(bit), [tmp0]"=&r"(tmp0), [tmp1]"=&r"(tmp1), [tmp2]"=&r"(tmp2),
+ [c_range]"+&r"(c->range), [c_low]"+&r"(c->low),
+ [c_bytestream]"+&r"(c->bytestream)
+ : [state]"r"(state), [tables]"r"(ff_h264_cabac_tables),
+#if !UNCHECKED_BITSTREAM_READER
+ [c_bytestream_end]"r"(c->bytestream_end),
+#endif
+ [lps_off]"i"(H264_LPS_RANGE_OFFSET),
+ [mlps_off]"i"(H264_MLPS_STATE_OFFSET + 128),
+ [norm_off]"i"(H264_NORM_SHIFT_OFFSET),
+ [cabac_mask]"i"(CABAC_MASK)
+ : "memory"
+ );
+
+ return bit;
+}
+
+#endif /* AVCODEC_MIPS_CABAC_H */
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