From: Rémi Denis-Courmont <r...@remlab.net>
VSETVLI xd, x0, ...' has rather nonobvious semantics:
- If xd is x0, then it preserves the current vector length.
- If xd is not x0, it sets the vector length to the supported maximum.
Also somewhat confusingly, while VMV.X.S always does its thing
regardless of the selected vector length, VMV.S.X does _nothing_ if the
selected vector length is zero.
So the current code breaks fails to initialise the accumulator if we
are unlucky to have a selected vector length of zero on entry. Fix it
by forcing the vector length to one.
---
libavcodec/riscv/audiodsp_rvv.S | 2 +-
libavutil/riscv/float_dsp_rvv.S | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/libavcodec/riscv/audiodsp_rvv.S b/libavcodec/riscv/audiodsp_rvv.S
index f4308f27c5..8e8bbd2058 100644
--- a/libavcodec/riscv/audiodsp_rvv.S
+++ b/libavcodec/riscv/audiodsp_rvv.S
@@ -21,7 +21,7 @@
#include "libavutil/riscv/asm.S"
func ff_scalarproduct_int16_rvv, zve32x
- vsetvli zero, zero, e16, m1, ta, ma
+ vsetivli zero, 1, e16, m1, ta, ma
vmv.s.x v8, zero
1:
vsetvli t0, a2, e16, m1, ta, ma
diff --git a/libavutil/riscv/float_dsp_rvv.S b/libavutil/riscv/float_dsp_rvv.S
index ab2e0c42d7..e105f2d574 100644
--- a/libavutil/riscv/float_dsp_rvv.S
+++ b/libavutil/riscv/float_dsp_rvv.S
@@ -167,7 +167,7 @@ endfunc
// a0 = (a0).(a1) [0..a2-1]
func ff_scalarproduct_float_rvv, zve32f
- vsetvli zero, zero, e32, m1, ta, ma
+ vsetivli zero, 1, e32, m1, ta, ma
vmv.s.x v8, zero
1:
vsetvli t0, a2, e32, m1, ta, ma
--
2.37.2
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