lavc/blockdsp: R-V V clear_blocks

C908:
blockdsp.clear_blocks_c: 128.2
blockdsp.clear_blocks_rvv_i64: 102.5

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

libavcodec/riscv/blockdsp_init.c

@@ -26,6 +26,7 @@
 #include "libavcodec/blockdsp.h"
 
 void ff_clear_block_rvv(int16_t *block);
+void ff_clear_blocks_rvv(int16_t *block);
 
 av_cold void ff_blockdsp_init_riscv(BlockDSPContext *c)
 {
@@ -34,6 +35,7 @@ av_cold void ff_blockdsp_init_riscv(BlockDSPContext *c)
 
     if (flags & AV_CPU_FLAG_RVV_I64 && ff_get_rv_vlenb() >= 16) {
         c->clear_block = ff_clear_block_rvv;
+        c->clear_blocks = ff_clear_blocks_rvv;
     }
 #endif
 }

libavcodec/riscv/blockdsp_rvv.S

@@ -27,3 +27,16 @@ func ff_clear_block_rvv, zve64x
 
         ret
 endfunc
+
+func ff_clear_blocks_rvv, zve64x
+        vsetivli      zero, 16, e64, m8, ta, ma
+        vmv.v.i       v0, 0
+
+        .rept 5
+        vse64.v       v0, (a0)
+        addi          a0, a0, 128
+        .endr
+        vse64.v       v0, (a0)
+
+        ret
+endfunc