From cdd38a2ffe9a6a092b5aee34cc5fe7fe20b72148 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?R=C3=A9mi=20Denis-Courmont?= Date: Sun, 17 Dec 2023 17:14:05 +0200 Subject: [PATCH] lavc/aacpsdsp: fix R-V V stereo interpolate The penultimate loop iteration could pick any vl such that: vlenb/4 < vl <= vlenb/2 Thus if the total length is not a multiple of vlenb/2, the vfadd.vf on the penultimate iteration would yield corrupt values for the last iteration. To avoid this, force vl = vlen/2 until the last iteration. Unfortunately this latent bug is not reproducible with either hardware or QEMU as of now. --- libavcodec/riscv/aacpsdsp_rvv.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/libavcodec/riscv/aacpsdsp_rvv.S b/libavcodec/riscv/aacpsdsp_rvv.S index f46b35fe91..a79d7d7818 100644 --- a/libavcodec/riscv/aacpsdsp_rvv.S +++ b/libavcodec/riscv/aacpsdsp_rvv.S @@ -234,7 +234,8 @@ func ff_ps_stereo_interpolate_rvv, zve32f vfmacc.vf v22, ft3, v24 fmul.s ft3, ft3, ft4 1: - vsetvli t0, a4, e32, m2, ta, ma + min t0, t0, a4 + vsetvli zero, t0, e32, m2, ta, ma vlseg2e32.v v0, (a0) // v0:l_re, v2:l_im sub a4, a4, t0 vlseg2e32.v v4, (a1) // v4:r_re, v6:r_im