From 8bdb6630627a5c304e61f5b81be3af6da77c4a67 Mon Sep 17 00:00:00 2001
From: sunyuechi <sunyuechi@iscas.ac.cn>
Date: Wed, 22 Nov 2023 14:57:29 +0800
Subject: [PATCH] lavc/ac3dsp: R-V V float_to_fixed24
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c910
    float_to_fixed24_c: 2207.2
    float_to_fixed24_rvv_f32: 696.2

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>
---
 libavcodec/riscv/Makefile      |  1 +
 libavcodec/riscv/ac3dsp_init.c |  4 ++++
 libavcodec/riscv/ac3dsp_rvv.S  | 39 ++++++++++++++++++++++++++++++++++
 3 files changed, 44 insertions(+)
 create mode 100644 libavcodec/riscv/ac3dsp_rvv.S

diff --git a/libavcodec/riscv/Makefile b/libavcodec/riscv/Makefile
index 2d0e6c19c8..29a7fec455 100644
--- a/libavcodec/riscv/Makefile
+++ b/libavcodec/riscv/Makefile
@@ -2,6 +2,7 @@ OBJS-$(CONFIG_AAC_DECODER) += riscv/aacpsdsp_init.o riscv/sbrdsp_init.o
 RVV-OBJS-$(CONFIG_AAC_DECODER) += riscv/aacpsdsp_rvv.o riscv/sbrdsp_rvv.o
 OBJS-$(CONFIG_AC3DSP) += riscv/ac3dsp_init.o \
                          riscv/ac3dsp_rvb.o
+RVV-OBJS-$(CONFIG_AC3DSP) += riscv/ac3dsp_rvv.o
 OBJS-$(CONFIG_ALAC_DECODER) += riscv/alacdsp_init.o
 RVV-OBJS-$(CONFIG_ALAC_DECODER) += riscv/alacdsp_rvv.o
 OBJS-$(CONFIG_AUDIODSP) += riscv/audiodsp_init.o \
diff --git a/libavcodec/riscv/ac3dsp_init.c b/libavcodec/riscv/ac3dsp_init.c
index 20f294f1de..118b2955ca 100644
--- a/libavcodec/riscv/ac3dsp_init.c
+++ b/libavcodec/riscv/ac3dsp_init.c
@@ -18,6 +18,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include <stddef.h>
 #include <stdint.h>
 
 #include "config.h"
@@ -26,6 +27,7 @@
 #include "libavcodec/ac3dsp.h"
 
 void ff_extract_exponents_rvb(uint8_t *exp, int32_t *coef, int nb_coefs);
+void ff_float_to_fixed24_rvv(int32_t *dst, const float *src, size_t len);
 
 av_cold void ff_ac3dsp_init_riscv(AC3DSPContext *c)
 {
@@ -34,5 +36,7 @@ av_cold void ff_ac3dsp_init_riscv(AC3DSPContext *c)
     if (flags & AV_CPU_FLAG_RVB_ADDR) {
         if (flags & AV_CPU_FLAG_RVB_BASIC)
             c->extract_exponents = ff_extract_exponents_rvb;
+        if (flags & AV_CPU_FLAG_RVV_F32)
+            c->float_to_fixed24 = ff_float_to_fixed24_rvv;
     }
 }
diff --git a/libavcodec/riscv/ac3dsp_rvv.S b/libavcodec/riscv/ac3dsp_rvv.S
new file mode 100644
index 0000000000..b8d32c4677
--- /dev/null
+++ b/libavcodec/riscv/ac3dsp_rvv.S
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2023 Institue of Software Chinese Academy of Sciences (ISCAS).
+ *
+ * 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 "config.h"
+#include "libavutil/riscv/asm.S"
+
+func ff_float_to_fixed24_rvv, zve32f
+        li            t1, 1 << 24
+        fcvt.s.w      f0, t1
+1:
+        vsetvli       t0, a2, e32, m8, ta, ma
+        sub           a2, a2, t0
+        vle32.v       v0, (a1)
+        vfmul.vf      v0, v0, f0
+        vfcvt.x.f.v   v0, v0
+        sh2add        a1, t0, a1
+        vse32.v       v0, (a0)
+        sh2add        a0, t0, a0
+        bnez          a2, 1b
+
+        ret
+endfunc