There are 32 pseudo-instructions for each floating-point comparison
instruction, but only 8 of them are actually valid in legacy-encoded mode.
The remaining 24 requires the use of VEX-encoded (v-prefixed) instructions
and can therefore be disregarded for this purpose.
AVX-512 consists of a plethora of different extensions, but in order to keep
things a bit more manageable we group together the following extensions
under a single baseline cpu flag which should cover SKL-X and future CPUs:
* AVX-512 Foundation (F)
* AVX-512 Conflict Detection Instructions (CD)
* AVX-512 Byte and Word Instructions (BW)
* AVX-512 Doubleword and Quadword Instructions (DQ)
* AVX-512 Vector Length Extensions (VL)
On x86-64 AVX-512 provides 16 additional vector registers, prefer using
those over existing ones since it allows us to avoid using `vzeroupper`
unless more than 16 vector registers are required. They also happen to
be volatile on Windows which means that we don't need to save and restore
existing xmm register contents unless more than 22 vector registers are
required.
Big thanks to Intel for their support.
Technically _tzcnt* intrinsics are only available when the BMI
instruction set is present. However the instruction encoding
degrades to "rep bsf" on older processors.
Clang for Windows debatably restricts the _tzcnt* instrinics behind
the __BMI__ architecture define, so check for its presence or
exclude the usage of these intrinics when clang is present.
See also:
https://ffmpeg.org/pipermail/ffmpeg-devel/2015-November/183404.htmlhttps://bugs.llvm.org/show_bug.cgi?id=30506http://lists.llvm.org/pipermail/cfe-dev/2016-October/051034.html
Signed-off-by: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Matt Oliver <protogonoi@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Improved version of VBROADCASTSS that works like the avx2 instruction.
Emulation of vpbroadcastd.
Horizontal sum HSUMPS that places the result in all elements.
Emulation of blendvps and pblendvb.
Signed-off-by: Ivan Kalvachev <ikalvachev@gmail.com>
Yasm:
src/libavfilter/x86/af_volume.asm:24: warning: Standard COFF does not support read-only data sections
src/libavfilter/x86/af_volume.asm:24: warning: Unrecognized qualifier `align'
Nasm:
src/libavfilter/x86/af_volume.asm:24: error: standard COFF does not support section alignment specification
src/libavutil/x86/x86inc.asm:92: ... from macro `SECTION_RODATA' defined here
Tested-by: Clément Bœsch <u@pkh.me>
Signed-off-by: James Almer <jamrial@gmail.com>
Due to a peculiarity in the ModR/M addressing encoding, the r12 and r13
registers sometimes requires an additional byte when used as a base register.
r14 and r15 doesn't have that issue, so prefer using them.
We overload the `call` instruction with a macro, but it would misbehave when
the macro argument wasn't a valid identifier. Fix it by explicitly checking
if the argument is an identifier.
Also do some small cosmetic changes: Drop pointless _MMX suffix from ABSD2
macro name, drop pointless check for MMX support, we always assume MMX is
available in our SIMD code, fix spelling.
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.
When allocating stack space with an alignment requirement that is larger
than the current stack alignment we need to store a copy of the original
stack pointer in order to be able to restore it later.
If we chose to use another register for this purpose we should not pick
eax/rax since it can be overwritten as a return value.
When allocating stack space with an alignment requirement that is larger
than the current stack alignment we need to store a copy of the original
stack pointer in order to be able to restore it later.
If we chose to use another register for this purpose we should not pick
eax/rax since it can be overwritten as a return value.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
libavutil/x86/float_dsp_init.c(144) : warning C4028: formal parameter 1 different from declaration
libavutil/x86/float_dsp_init.c(144) : warning C4028: formal parameter 2 different from declaration
James Almer
Jun Zhao
alexander schmid
Diego Biurrun
Henrik Gramner
James Darnley
Martin Vignali
Dale Curtis
Ivan Kalvachev
Anton Mitrofanov
Michael Niedermayer
Alexandra Hájková
Anton Khirnov
Fiona Glaser