This makes the code much simpler (especially for adding support
for other instruction set extensions), avoids needing inline
assembly for this feature, and generally is more of the canonical
way to do this.
The CPU feature detection was added in
493fcde50a, using HWCAP_CPUID.
The argument for using that, was that HWCAP_CPUID was added much
earlier in the kernel (in Linux v4.11), while the HWCAP flags for
individual features always come later. This allows detecting support
for new CPU extensions before the kernel exposes information about
them via hwcap flags.
However in practice, there's probably quite little advantage in this.
E.g. HWCAP2_I8MM was added in Linux v5.10 - long after HWCAP_CPUID,
but there's probably very little practical cases where one would
run a kernel older than that on a CPU that supports those instructions.
Additionally, we provide our own definitions of the flag values to
check (as they are fixed constants anyway), with names not conflicting
with the ones from system headers. This reduces the number of ifdefs
needed, and allows detecting those features even if building with
userland headers that are lacking the definitions of those flags.
Also, slightly older versions of QEMU, e.g. 6.2 in Ubuntu 22.04,
do expose support for these features via HWCAP flags, but the
emulated cpuid registers are missing the bits for exposing e.g. I8MM.
(This issue is fixed in later versions of QEMU though.)
Signed-off-by: Martin Storsjö <martin@martin.st>
This is not actually used for anything. The configure check causes the
CPU feature flag to be set, but nothing consumes it at all.
While AArch64 does have VFP, it is only used for the scalar C code.
Conversely, it is still possible to disable VFP, by changing the
C compiler flags as before (though that only makes sense for an
hypothetical non-standard Armv8 platform without VFP).
Note that this retains the "vfp" option flag, for backward
compatibility and on the very remote but theoretically possible chance
that FFmpeg actually makes use of it in the future.
AV_CPU_FLAG_VFP is retained as it is actually used by AArch32.
For now, there's not much value in this since Clang don't support
enabling the dotprod or i8mm features with either .arch_extension
or .arch (it has to be enabled by the base arch flags passed to
the compiler). But it may be supported in the future.
Signed-off-by: Martin Storsjö <martin@martin.st>
NEON and VFP are currently mandatory for all ARMv8 profiles. Both are
handled as extensions as far as cpuflags are concerned. This is
consistent with handling x86_64 which always has SSE2, but still
handles it as an extension.
These decoders use a special non-MPEG2 IDCT. Call it directly
instead of going through dsputil. There is never any reason
to use a regular IDCT with these decoders or to use the EA IDCT
with other codecs.
This also fixes the bizarre situation of eamad and eatqi decoding
incorrectly if eatgq is disabled.
Signed-off-by: Mans Rullgard <mans@mansr.com>
The were broken since August of 2010 without anyone noticing until
three weeks ago. Nobody cares about it anymore and hopefully Marvell
will support NEON like in the PXA978 from now on.
It contains optimizations that are not specific to i386 and
libavutil uses this naming scheme already.
Originally committed as revision 16270 to svn://svn.ffmpeg.org/ffmpeg/trunk
c is 1.9x faster than previous c (on various x86 cpus), sse is 1.6x faster than previous sse.
Originally committed as revision 14698 to svn://svn.ffmpeg.org/ffmpeg/trunk
include paths in the source files.
mostly from a patch by Ronald S. Bultje, rbultje ronald.bitfreak net
Originally committed as revision 9034 to svn://svn.ffmpeg.org/ffmpeg/trunk
Patch by Zuxy Meng, zuxy <<dot>> meng >>at<< gmail <<dot>> com
Minor non-functional diff-related fixes by me.
Originally committed as revision 5125 to svn://svn.ffmpeg.org/ffmpeg/trunk
Brad Smith
Martin Storsjö
Reimar Döffinger
Rémi Denis-Courmont
James Almer
Janne Grunau
Janne Grunau
Diego Biurrun
Mans Rullgard
Loren Merritt
Ramiro Polla
Ronald S. Bultje
Zuxy Meng