[FFmpeg-devel] [PATCH] riscv: vc1dsp: Don't check vlenb before checking the CPU flags

[Rémi Denis-Courmont]

Le 15 décembre 2023 15:02:04 GMT+02:00, "Martin Storsjö" <martin at martin.st> a écrit :
>We can't call ff_get_rv_vlenb() if we don't have RVV available
>at all.
>
>Due to the SIGILL signal handler in checkasm catching it, in an
>unexpected place, this caused checkasm to hang instead of reporting
>the issue.
>---
> libavcodec/riscv/vc1dsp_init.c | 16 +++++++---------
> 1 file changed, 7 insertions(+), 9 deletions(-)
>
>diff --git a/libavcodec/riscv/vc1dsp_init.c b/libavcodec/riscv/vc1dsp_init.c
>index 0d22d28f4d..2bb7e7fe8f 100644
>--- a/libavcodec/riscv/vc1dsp_init.c
>+++ b/libavcodec/riscv/vc1dsp_init.c
>@@ -35,15 +35,13 @@ av_cold void ff_vc1dsp_init_riscv(VC1DSPContext *dsp)
> #if HAVE_RVV
>     int flags = av_get_cpu_flags();
> 
>-    if (ff_get_rv_vlenb() >= 16) {
>-        if (flags & AV_CPU_FLAG_RVV_I64) {
>-            dsp->vc1_inv_trans_8x8_dc = ff_vc1_inv_trans_8x8_dc_rvv;
>-            dsp->vc1_inv_trans_8x4_dc = ff_vc1_inv_trans_8x4_dc_rvv;
>-        }
>-        if (flags & AV_CPU_FLAG_RVV_I32) {
>-            dsp->vc1_inv_trans_4x8_dc = ff_vc1_inv_trans_4x8_dc_rvv;
>-            dsp->vc1_inv_trans_4x4_dc = ff_vc1_inv_trans_4x4_dc_rvv;
>-        }
>+    if (flags & AV_CPU_FLAG_RVV_I64 && ff_get_rv_vlenb() >= 16) {
>+        dsp->vc1_inv_trans_8x8_dc = ff_vc1_inv_trans_8x8_dc_rvv;
>+        dsp->vc1_inv_trans_8x4_dc = ff_vc1_inv_trans_8x4_dc_rvv;
>+    }
>+    if (flags & AV_CPU_FLAG_RVV_I32 && ff_get_rv_vlenb() >= 16) {
>+        dsp->vc1_inv_trans_4x8_dc = ff_vc1_inv_trans_4x8_dc_rvv;
>+        dsp->vc1_inv_trans_4x4_dc = ff_vc1_inv_trans_4x4_dc_rvv;

I64 implies I32 so it is not necessary to check vlenb twice. That's what I was going for originally in my then review comments but then woopsie.

>     }
> #endif
> }