Fixes use of bultins on clang x86_64-pc-windows-msvc which does not
define any __GNUC__. Also on other targets __GNUC__ is defined to 4 by
default, so any feature testing based on version is not really valid.
Signed-off-by: Kacper Michajłow <kasper93@gmail.com>
Signed-off-by: Martin Storsjö <martin@martin.st>
GCC/Clang is smart enough to emit minss/maxss the same way as these functions.
The only theoretical benefit was in x86_32, where x87 floats are used, but the
penalty of making the clipping opaque to the compiler's scheduler plus moving
values from mmx regs to xmm and back will offset any potential speedup.
x86_32 builds targetting anything made in the last two decades and a half
should use -msse -mfp=sse anyway.
Signed-off-by: James Almer <jamrial@gmail.com>
Changes av_clipf to return amin if a is nan.
Before if a is nan av_clipf_c returned nan and
av_clipf_sse would return amax. Now the both
should behave the same.
This works because nan > amin is false.
The max(nan, amin) will be amin.
Signed-off-by: James Almer <jamrial@gmail.com>
It seems to miscompile them
Should fix fate-ra-288 and fate-twinvq
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: James Almer <jamrial@gmail.com>
ICC versions older than atleast 12.1.6 dont have the tzcnt intrinsics.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Matt Oliver <protogonoi@gmail.com>
GCC 4.3 and later do the right thing with the plain C code. Earlier
versions in 32-bit mode generate one extra instruction, needlessly
zeroing what would be the high half of the shifted value. At least
two gcc configurations miscompile the inline asm in some situations.
In 64-bit mode, all gcc versions generate imul r64, r64 followed by
shr. On Intel i7 and later, this imul is faster 32-bit mul. On
older Intel and all AMD, it is slightly slower. On Atom it is much
slower.
Considering where the FASTDIV macro is used, any overall negative
performance impact of this change should be negligible. If anyone
cares, they should file a bug against gcc and get the instruction
selection fixed.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This reduces the number of false dependencies on header files and
speeds up compilation.
Originally committed as revision 22407 to svn://svn.ffmpeg.org/ffmpeg/trunk
