lavc/flacdsp: R-V V flac_wasted32

T-Head C908:
flac_wasted_32_c:       949.0
flac_wasted_32_rvv_i32: 278.7

libavcodec/riscv/flacdsp_init.c

@@ -31,6 +31,7 @@ void ff_flac_lpc32_rvv(int32_t *decoded, const int coeffs[32],
                        int pred_order, int qlevel, int len);
 void ff_flac_lpc32_rvv_simple(int32_t *decoded, const int coeffs[32],
                               int pred_order, int qlevel, int len);
+void ff_flac_wasted32_rvv(int32_t *, int shift, int len);
 void ff_flac_decorrelate_indep2_16_rvv(uint8_t **out, int32_t **in,
                                        int channels, int len, int shift);
 void ff_flac_decorrelate_indep4_16_rvv(uint8_t **out, int32_t **in,
@@ -79,7 +80,11 @@ av_cold void ff_flacdsp_init_riscv(FLACDSPContext *c, enum AVSampleFormat fmt,
             else
                 c->lpc32 = ff_flac_lpc32_rvv;
         }
+# endif
+
+        c->wasted32 = ff_flac_wasted32_rvv;
 
+# if (__riscv_xlen >= 64)
         switch (fmt) {
         case AV_SAMPLE_FMT_S16:
             switch (channels) {
@@ -119,8 +124,8 @@ av_cold void ff_flacdsp_init_riscv(FLACDSPContext *c, enum AVSampleFormat fmt,
             c->decorrelate[2] = ff_flac_decorrelate_rs_32_rvv;
             c->decorrelate[3] = ff_flac_decorrelate_ms_32_rvv;
             break;
-# endif
         }
+# endif
     }
 #endif
 }

libavcodec/riscv/flacdsp_rvv.S

@@ -100,7 +100,22 @@ func ff_flac_lpc32_rvv_simple, zve64x
 
         ret
 endfunc
+#endif
+
+func ff_flac_wasted32_rvv, zve32x
+1:
+        vsetvli t0, a2, e32, m8, ta, ma
+        vle32.v v8, (a0)
+        sub     a2, a2, t0
+        vsll.vx v8, v8, a1
+        vse32.v v8, (a0)
+        sh2add  a0, t0, a0
+        bnez    a2, 1b
 
+        ret
+endfunc
+
+#if (__riscv_xlen == 64)
 func ff_flac_decorrelate_indep2_16_rvv, zve32x
         ld      a0,  (a0)
         ld      a2, 8(a1)