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| author | James Darnley <jdarnley@obe.tv> | 2017-02-11 13:25:09 +0100 |
|---|---|---|
| committer | James Darnley <jdarnley@obe.tv> | 2017-02-18 20:26:51 +0100 |
| commit | 7627df15d411a69f236b4650e88b1ab911f38efc (patch) | |
| tree | 5c96771296d82fc23b52e8959e364a55cd368ba1 | |
| parent | e18bc2114f3deb8ef1ab9ddaef282c8d9678669d (diff) | |
| download | ffmpeg-7627df15d411a69f236b4650e88b1ab911f38efc.tar.gz | |
x86util: import MOVHL macro
Originally committed to x264 in 1637239a by Henrik Gramner who has
agreed to re-license it as LGPL. Original commit message follows.
x86: Avoid some bypass delays and false dependencies
A bypass delay of 1-3 clock cycles may occur on some CPUs when transitioning
between int and float domains, so try to avoid that if possible.
| -rw-r--r-- | libavutil/x86/x86util.asm | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/libavutil/x86/x86util.asm b/libavutil/x86/x86util.asm index c063436e0a..1408f0a176 100644 --- a/libavutil/x86/x86util.asm +++ b/libavutil/x86/x86util.asm @@ -876,3 +876,15 @@ psrlq %1, 8*(%2) %endif %endmacro + +%macro MOVHL 2 ; dst, src +%ifidn %1, %2 + punpckhqdq %1, %2 +%elif cpuflag(avx) + punpckhqdq %1, %2, %2 +%elif cpuflag(sse4) + pshufd %1, %2, q3232 ; pshufd is slow on some older CPUs, so only use it on more modern ones +%else + movhlps %1, %2 ; may cause an int/float domain transition and has a dependency on dst +%endif +%endmacro |