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| author | Timothy Gu <timothygu99@gmail.com> | 2016-01-30 10:52:44 -0800 |
|---|---|---|
| committer | Timothy Gu <timothygu99@gmail.com> | 2016-02-08 16:25:44 -0800 |
| commit | cb8646af24bd8e9627cc5e1c62b049a00fe0b07b (patch) | |
| tree | 7094dfe5af383a9c8435b1678b8f8851f6c3466b | |
| parent | 8e46c7c1e7f5e775a152f6d75a08e93ddb9f7565 (diff) | |
| download | ffmpeg-cb8646af24bd8e9627cc5e1c62b049a00fe0b07b.tar.gz | |
configure: Enable GCC vectorization on ≥4.9 on x86
4.9 was released precisely nine years after the first GCC version with
autovectorizer (4.0) and six years after the first GCC version with
`-ftree-vectorize` default to enabled on `-O3` (4.3). We've given GCC
enough time to fix those bugs.
FATE passes here on a x86-64 machine with both GCC 4.9.2 and 5.3.1.
Some optimization hotspots benefit greatly from this change, especially
those without handwritten assembly. For instance, the main function in
vf_phase is now 1.6x faster (1.2x overall) on my machine.
| -rwxr-xr-x | configure | 6 |
1 files changed, 5 insertions, 1 deletions
@@ -5935,7 +5935,11 @@ elif enabled ccc; then add_cflags -msg_disable nonstandcast add_cflags -msg_disable unsupieee elif enabled gcc; then - check_optflags -fno-tree-vectorize + case $gcc_basever in + 4.9*) enabled x86 || check_optflags -fno-tree-vectorize ;; + 4.*) check_optflags -fno-tree-vectorize ;; + *) enabled x86 || check_optflags -fno-tree-vectorize ;; + esac check_cflags -Werror=format-security check_cflags -Werror=implicit-function-declaration check_cflags -Werror=missing-prototypes |