[FFmpeg-devel] [PATCH v3 2/5] avcodec/mips: Refine get_cabac_inline_mips.
Shiyou Yin
yinshiyou-hf at loongson.cn
Tue Mar 30 15:51:52 EEST 2021
1. Refined function get_cabac_inline_mips.
2. Optimize function get_cabac_bypass and get_cabac_bypass_sign.
Speed of decoding h264: 4.89x ==> 5.05x(tested on 3A4000).
---
libavcodec/mips/cabac.h | 131 +++++++++++++++++++++++++++++++++++++-----------
1 file changed, 102 insertions(+), 29 deletions(-)
diff --git a/libavcodec/mips/cabac.h b/libavcodec/mips/cabac.h
index 3d09e93..0ee7594 100644
--- a/libavcodec/mips/cabac.h
+++ b/libavcodec/mips/cabac.h
@@ -2,7 +2,8 @@
* Loongson SIMD optimized h264chroma
*
* Copyright (c) 2018 Loongson Technology Corporation Limited
- * Copyright (c) 2018 Shiyou Yin <yinshiyou-hf at loongson.cn>
+ * Contributed by Shiyou Yin <yinshiyou-hf at loongson.cn>
+ * Gu Xiwei(guxiwei-hf at loongson.cn)
*
* This file is part of FFmpeg.
*
@@ -25,18 +26,18 @@
#define AVCODEC_MIPS_CABAC_H
#include "libavcodec/cabac.h"
-#include "libavutil/mips/asmdefs.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_mips(CABACContext *c,
- uint8_t * const state){
+ 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_SLL "%[tmp0], %[tmp0], 0x01 \n\t"
PTR_ADDU "%[tmp0], %[tmp0], %[tables] \n\t"
PTR_ADDU "%[tmp0], %[tmp0], %[bit] \n\t"
/* tmp1: RangeLPS */
@@ -44,18 +45,11 @@ static av_always_inline int get_cabac_inline_mips(CABACContext *c,
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*/
+ "slt %[tmp2], %[tmp0], %[c_low] \n\t"
"beqz %[tmp2], 1f \n\t"
- PTR_SLL "%[tmp0], %[c_range], 0x11 \n\t"
+ "move %[c_range], %[tmp1] \n\t"
+ "not %[bit], %[bit] \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 */
@@ -70,23 +64,18 @@ static av_always_inline int get_cabac_inline_mips(CABACContext *c,
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_ADDIU "%[tmp0], %[c_low], -0x01 \n\t"
+ "and %[tmp1], %[c_low], %[cabac_mask] \n\t"
+ "bnez %[tmp1], 1f \n\t"
+ PTR_ADDIU "%[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"
+ /* tmp2: ff_h264_norm_shift[x >> (CABAC_BITS - 1)] */
"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"
+
+ "lhu %[tmp0], 0(%[c_bytestream]) \n\t"
+ "wsbh %[tmp0], %[tmp0] \n\t"
PTR_SLL "%[tmp0], %[tmp0], 0x01 \n\t"
-#endif
PTR_SUBU "%[tmp0], %[tmp0], %[cabac_mask] \n\t"
"li %[tmp1], 0x07 \n\t"
@@ -94,10 +83,13 @@ static av_always_inline int get_cabac_inline_mips(CABACContext *c,
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"
+#if UNCHECKED_BITSTREAM_READER
+ PTR_ADDIU "%[c_bytestream], %[c_bytestream], 0x02 \n\t"
+#else
+ "slt %[tmp0], %[c_bytestream], %[c_bytestream_end] \n\t"
+ PTR_ADDIU "%[tmp2], %[c_bytestream], 0x02 \n\t"
+ "movn %[c_bytestream], %[tmp2], %[tmp0] \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),
@@ -116,4 +108,85 @@ static av_always_inline int get_cabac_inline_mips(CABACContext *c,
return bit;
}
+#define get_cabac_bypass get_cabac_bypass_mips
+static av_always_inline int get_cabac_bypass_mips(CABACContext *c)
+{
+ mips_reg tmp0, tmp1;
+ int res = 0;
+ __asm__ volatile(
+ PTR_SLL "%[c_low], %[c_low], 0x01 \n\t"
+ "and %[tmp0], %[c_low], %[cabac_mask] \n\t"
+ "bnez %[tmp0], 1f \n\t"
+ "lhu %[tmp1], 0(%[c_bytestream]) \n\t"
+ "wsbh %[tmp1], %[tmp1] \n\t"
+ PTR_SLL "%[tmp1], %[tmp1], 0x01 \n\t"
+ PTR_SUBU "%[tmp1], %[tmp1], %[cabac_mask] \n\t"
+ PTR_ADDU "%[c_low], %[c_low], %[tmp1] \n\t"
+#if UNCHECKED_BITSTREAM_READER
+ PTR_ADDIU "%[c_bytestream], %[c_bytestream], 0x02 \n\t"
+#else
+ "slt %[tmp0], %[c_bytestream], %[c_bytestream_end] \n\t"
+ PTR_ADDIU "%[tmp1], %[c_bytestream], 0x02 \n\t"
+ "movn %[c_bytestream], %[tmp1], %[tmp0] \n\t"
+#endif
+ "1: \n\t"
+ PTR_SLL "%[tmp1], %[c_range], 0x11 \n\t"
+ "slt %[tmp0], %[c_low], %[tmp1] \n\t"
+ PTR_SUBU "%[tmp1], %[c_low], %[tmp1] \n\t"
+ "movz %[res], %[one], %[tmp0] \n\t"
+ "movz %[c_low], %[tmp1], %[tmp0] \n\t"
+ : [tmp0]"=&r"(tmp0), [tmp1]"=&r"(tmp1), [res]"+&r"(res),
+ [c_range]"+&r"(c->range), [c_low]"+&r"(c->low),
+ [c_bytestream]"+&r"(c->bytestream)
+ : [cabac_mask]"r"(CABAC_MASK),
+#if !UNCHECKED_BITSTREAM_READER
+ [c_bytestream_end]"r"(c->bytestream_end),
+#endif
+ [one]"r"(0x01)
+ : "memory"
+ );
+ return res;
+}
+
+#define get_cabac_bypass_sign get_cabac_bypass_sign_mips
+static av_always_inline int get_cabac_bypass_sign_mips(CABACContext *c, int val)
+{
+ mips_reg tmp0, tmp1;
+ int res = val;
+ __asm__ volatile(
+ PTR_SLL "%[c_low], %[c_low], 0x01 \n\t"
+ "and %[tmp0], %[c_low], %[cabac_mask] \n\t"
+ "bnez %[tmp0], 1f \n\t"
+ "lhu %[tmp1], 0(%[c_bytestream]) \n\t"
+ "wsbh %[tmp1], %[tmp1] \n\t"
+ PTR_SLL "%[tmp1], %[tmp1], 0x01 \n\t"
+ PTR_SUBU "%[tmp1], %[tmp1], %[cabac_mask] \n\t"
+ PTR_ADDU "%[c_low], %[c_low], %[tmp1] \n\t"
+#if UNCHECKED_BITSTREAM_READER
+ PTR_ADDIU "%[c_bytestream], %[c_bytestream], 0x02 \n\t"
+#else
+ "slt %[tmp0], %[c_bytestream], %[c_bytestream_end] \n\t"
+ PTR_ADDIU "%[tmp1], %[c_bytestream], 0x02 \n\t"
+ "movn %[c_bytestream], %[tmp1], %[tmp0] \n\t"
+#endif
+ "1: \n\t"
+ PTR_SLL "%[tmp1], %[c_range], 0x11 \n\t"
+ "slt %[tmp0], %[c_low], %[tmp1] \n\t"
+ PTR_SUBU "%[tmp1], %[c_low], %[tmp1] \n\t"
+ "movz %[c_low], %[tmp1], %[tmp0] \n\t"
+ PTR_SUBU "%[tmp1], %[zero], %[res] \n\t"
+ "movn %[res], %[tmp1], %[tmp0] \n\t"
+ : [tmp0]"=&r"(tmp0), [tmp1]"=&r"(tmp1), [res]"+&r"(res),
+ [c_range]"+&r"(c->range), [c_low]"+&r"(c->low),
+ [c_bytestream]"+&r"(c->bytestream)
+ : [cabac_mask]"r"(CABAC_MASK),
+#if !UNCHECKED_BITSTREAM_READER
+ [c_bytestream_end]"r"(c->bytestream_end),
+#endif
+ [zero]"r"(0x0)
+ : "memory"
+ );
+
+ return res;
+}
#endif /* AVCODEC_MIPS_CABAC_H */
--
2.1.0
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