deinterlace: add RV-V merge functions

modules/video_filter/Makefile.am

@@ -191,6 +191,10 @@ if HAVE_SVE
 libdeinterlace_plugin_la_SOURCES += video_filter/deinterlace/merge_sve.S
 libdeinterlace_plugin_la_CPPFLAGS += -DCAN_COMPILE_SVE
 endif
+if HAVE_RVV
+libdeinterlace_plugin_la_SOURCES += video_filter/deinterlace/merge_rvv.S
+libdeinterlace_plugin_la_CPPFLAGS += -DCAN_COMPILE_RVV
+endif
 libdeinterlace_plugin_la_LIBADD = libdeinterlace_common.la
 video_filter_LTLIBRARIES += libdeinterlace_plugin.la
 

modules/video_filter/deinterlace/deinterlace.c

@@ -578,6 +578,11 @@ notsupp:
     if( vlc_CPU_ARM_NEON() )
         p_sys->pf_merge = pixel_size == 1 ? merge8_arm64_neon : merge16_arm64_neon;
     else
+#endif
+#if defined(CAN_COMPILE_RVV)
+    if( vlc_CPU_RV_V() )
+        p_sys->pf_merge = pixel_size == 1 ? merge8_rvv : merge16_rvv;
+    else
 #endif
     {
         p_sys->pf_merge = pixel_size == 1 ? Merge8BitGeneric : Merge16BitGeneric;

modules/video_filter/deinterlace/merge.h

@@ -159,6 +159,9 @@ void merge16_arm64_neon (void *, const void *, const void *, size_t);
 void merge8_arm_sve(void *, const void *, const void *, size_t);
 void merge16_arm_sve(void *, const void *, const void *, size_t);
 
+void merge8_rvv(void *, const void *, const void *, size_t);
+void merge16_rvv(void *, const void *, const void *, size_t);
+
 /*****************************************************************************
  * EndMerge routines
  *****************************************************************************/

modules/video_filter/deinterlace/merge_rvv.S

+/******************************************************************************
+ * merge_rvv.S: RISC-V Vector mean
+ ******************************************************************************
+ * Copyright (C) 2022 Rémi Denis-Courmont
+ *
+ * This program 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.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+	.option arch, +v
+	.text
+	.align	2
+
+	.globl	merge8_rvv
+	.type	merge8_rvv, %function
+merge8_rvv:
+	csrwi	vxrm, 0
+1:	vsetvli	t0, a3, e8, m8, ta, ma
+	vle8.v	v16, (a1)
+	add	a1, a1, t0
+	vle8.v	v24, (a2)
+	add	a2, a2, t0
+	vaaddu.vv	v16, v16, v24
+	sub	a3, a3, t0
+	vse8.v	v16, (a0)
+	add	a0, a0, t0
+	bnez	a3, 1b
+	ret
+
+	.globl	merge16_rvv
+	.type	merge16_rvv, %function
+merge16_rvv:
+	csrwi	vxrm, 0
+	srli	a3, a3, 1
+1:	vsetvli	t0, a3, e16, m8, ta, ma
+	slli	t1, t0, 1
+	vle16.v	v16, (a1)
+	add	a1, a1, t1
+	vle16.v	v24, (a2)
+	add	a2, a2, t1
+	vaaddu.vv	v16, v16, v24
+	sub	a3, a3, t0
+	vse16.v	v16, (a0)
+	add	a0, a0, t1
+	bnez	a3, 1b
+	ret
+