Hi, FWIW I don't really care personally but judging by the original author and their affiliation, the intent was most probably to enable this for RISC-V / RVA23.
On that platform it is *probably* safe to enable vectorisation on all GCC versions but I have not tested it. In fact, I don't have an RVA23-conformant board. Le 5 août 2025 21:15:26 GMT+07:00, "Martin Storsjö" <c...@ffmpeg.org> a écrit : >PR #20120 opened by Martin Storsjö (mstorsjo) >URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20120 >Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20120.patch > >This changes configure to stop disabling -ftree-vectorize on >GCC versions 13 and newer, on major architectures. > >Background: >- Original `-fno-tree-vectorize` was added in 2009 in commit > 973859f5230e to avoid compiler errors. >- Re-enabled in 2016 in commit cb8646af24bd but caused failures due > to inline CABAC assembly issues and was disabled again in > fd6dbc53855fb. >- Commit 182663a58a7a in 2023 fixed the inline CABAC assembly issues. >- Recent versions of GCC, in particular 13 and newer, seem to > generally work reliably with respect to vectorization, although bugs > have been observed on Loongarch. > >Cautiously allow the GCC default of having vectorization enabled, >on major architectures where we expect to see enough testing. If >further issues are observed, they should be reported and noted here in >configure, so the workarounds can be scoped and version limited. > > >From f95261fab763cae5723513c9281d073048284ed4 Mon Sep 17 00:00:00 2001 >From: Jiawei <jia...@iscas.ac.cn> >Date: Mon, 14 Jul 2025 19:29:57 +0800 >Subject: [PATCH] gcc: Don't disable '-ftree-vectorize' on GCC >= 13 on major > architectures > >This changes configure to stop disabling -ftree-vectorize on >GCC versions 13 and newer, on major architectures. > >Background: >- Original `-fno-tree-vectorize` was added in 2009 in commit > 973859f5230e to avoid compiler errors. >- Re-enabled in 2016 in commit cb8646af24bd but caused failures due > to inline CABAC assembly issues and was disabled again in > fd6dbc53855fb. >- Commit 182663a58a7a in 2023 fixed the inline CABAC assembly issues. >- Recent versions of GCC, in particular 13 and newer, seem to > generally work reliably with respect to vectorization, although bugs > have been observed on Loongarch. > >Cautiously allow the GCC default of having vectorization enabled, >on major architectures where we expect to see enough testing. If >further issues are observed, they should be reported and noted here in >configure, so the workarounds can be scoped and version limited. >--- > Changelog | 1 + > configure | 20 +++++++++++++++++++- > 2 files changed, 20 insertions(+), 1 deletion(-) > >diff --git a/Changelog b/Changelog >index 04db8e15b2..b7704604f4 100644 >--- a/Changelog >+++ b/Changelog >@@ -26,6 +26,7 @@ version <next>: > - OpenHarmony hardware decoder/encoder > - Colordetect filter > - Add vf_scale_d3d11 filter >+- No longer disabling GCC autovectorization, on X86, ARM and AArch64 > > > version 7.1: >diff --git a/configure b/configure >index c0a4c3c87c..760e27fd70 100755 >--- a/configure >+++ b/configure >@@ -7714,7 +7714,25 @@ if enabled icc; then > disable aligned_stack > fi > elif enabled gcc; then >- check_optflags -fno-tree-vectorize >+ gcc_version=$($cc -dumpversion) >+ major_version=${gcc_version%%.*} >+ if [ $major_version -lt 13 ]; then >+ # Disable tree-vectorize for GCC <13 - it has historically been buggy. >+ check_optflags -fno-tree-vectorize >+ else >+ case $arch in >+ x86|arm|aarch64) >+ # Allow the default of having tree-vectorize enabled on well >tested >+ # architectures. >+ ;; >+ *) >+ # Disable tree-vectorize on potentially less tested >+ # architectures. Known issues: >+ # - https://gcc.gnu.org/PR121064 on Loongarch >+ check_optflags -fno-tree-vectorize >+ ;; >+ esac >+ fi > check_cflags -Werror=format-security > check_cflags -Werror=implicit-function-declaration > check_cflags -Werror=missing-prototypes >-- >2.49.1 > >_______________________________________________ >ffmpeg-devel mailing list >ffmpeg-devel@ffmpeg.org >https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > >To unsubscribe, visit link above, or email >ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
