[FFmpeg-devel] [PATCH 18/18] lavu/riscv: fixed vector sum-and-difference with RVV

[remi at remlab.net]

From: Rémi Denis-Courmont <remi at remlab.net>

---
 libavutil/fixed_dsp.c            |  4 +++-
 libavutil/fixed_dsp.h            |  1 +
 libavutil/riscv/Makefile         |  4 +++-
 libavutil/riscv/fixed_dsp_init.c | 36 ++++++++++++++++++++++++++++++
 libavutil/riscv/fixed_dsp_rvv.S  | 38 ++++++++++++++++++++++++++++++++
 5 files changed, 81 insertions(+), 2 deletions(-)
 create mode 100644 libavutil/riscv/fixed_dsp_init.c
 create mode 100644 libavutil/riscv/fixed_dsp_rvv.S

diff --git a/libavutil/fixed_dsp.c b/libavutil/fixed_dsp.c
index 154f3bc2d3..bc847949dc 100644
--- a/libavutil/fixed_dsp.c
+++ b/libavutil/fixed_dsp.c
@@ -162,7 +162,9 @@ AVFixedDSPContext * avpriv_alloc_fixed_dsp(int bit_exact)
     fdsp->butterflies_fixed = butterflies_fixed_c;
     fdsp->scalarproduct_fixed = scalarproduct_fixed_c;
 
-#if ARCH_X86
+#if ARCH_RISCV
+    ff_fixed_dsp_init_riscv(fdsp);
+#elif ARCH_X86
     ff_fixed_dsp_init_x86(fdsp);
 #endif
 
diff --git a/libavutil/fixed_dsp.h b/libavutil/fixed_dsp.h
index fec806ff2d..1217d3a53b 100644
--- a/libavutil/fixed_dsp.h
+++ b/libavutil/fixed_dsp.h
@@ -161,6 +161,7 @@ typedef struct AVFixedDSPContext {
  */
 AVFixedDSPContext * avpriv_alloc_fixed_dsp(int strict);
 
+void ff_fixed_dsp_init_riscv(AVFixedDSPContext *fdsp);
 void ff_fixed_dsp_init_x86(AVFixedDSPContext *fdsp);
 
 /**
diff --git a/libavutil/riscv/Makefile b/libavutil/riscv/Makefile
index 89a8d0d990..1597154ba5 100644
--- a/libavutil/riscv/Makefile
+++ b/libavutil/riscv/Makefile
@@ -1,3 +1,5 @@
 OBJS +=     riscv/float_dsp_init.o \
+            riscv/fixed_dsp_init.o \
             riscv/cpu.o
-RVV-OBJS += riscv/float_dsp_rvv.o
+RVV-OBJS += riscv/float_dsp_rvv.o \
+            riscv/fixed_dsp_rvv.o
diff --git a/libavutil/riscv/fixed_dsp_init.c b/libavutil/riscv/fixed_dsp_init.c
new file mode 100644
index 0000000000..fc143fb419
--- /dev/null
+++ b/libavutil/riscv/fixed_dsp_init.c
@@ -0,0 +1,36 @@
+/*
+ * 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 <stdint.h>
+
+#include "config.h"
+#include "libavutil/attributes.h"
+#include "libavutil/cpu.h"
+#include "libavutil/fixed_dsp.h"
+
+void ff_butterflies_fixed_rvv(int *v1, int *v2, int len);
+
+av_cold void ff_fixed_dsp_init_riscv(AVFixedDSPContext *fdsp)
+{
+#if HAVE_RVV
+    int flags = av_get_cpu_flags();
+
+    if (flags & AV_CPU_FLAG_ZVE32X)
+        fdsp->butterflies_fixed = ff_butterflies_fixed_rvv;
+#endif
+}
diff --git a/libavutil/riscv/fixed_dsp_rvv.S b/libavutil/riscv/fixed_dsp_rvv.S
new file mode 100644
index 0000000000..beb1b949f7
--- /dev/null
+++ b/libavutil/riscv/fixed_dsp_rvv.S
@@ -0,0 +1,38 @@
+/*
+ * 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 "asm.S"
+
+// (a0) = (a0) + (a1), (a1) = (a0) - (a1) [0..a2-1]
+func ff_butterflies_fixed_rvv, zve32x
+1:      vsetvli t0, a2, e32, m8, ta, ma
+        slli    t1, t0, 2
+        vle32.v v16, (a0)
+        vle32.v v24, (a1)
+        vadd.vv v0, v16, v24
+        vsub.vv v8, v16, v24
+        sub     a2, a2, t0
+        vse32.v v0, (a0)
+        add     a0, a0, t1
+        vse32.v v8, (a1)
+        add     a1, a1, t1
+        bnez    a2, 1b
+
+        ret
+endfunc
-- 
2.37.2