FFmpeg/aarch64 at a1be08ba0515b0224f7c433fc471e61013a12ff2 - FFmpeg - Gitea: Git with a cup of tea

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Martin Storsjö e30369bc1c aarch64: Use regular hwcaps flags instead of HWCAP_CPUID for CPU feature detection on Linux 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>		9 months ago
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Makefile	lavu/tx: implement aarch64 NEON SIMD FFT	2 years ago
asm.S	aarch64: Only enable extensions in the intended files/regions	1 year ago
bswap.h	aarch64: relax byte-swap assembler constraints	2 years ago
cpu.c	aarch64: Use regular hwcaps flags instead of HWCAP_CPUID for CPU feature detection on Linux	9 months ago
cpu.h	aarch64: Add cpu flags for the dotprod and i8mm extensions	1 year ago
float_dsp_init.c	Merge remote-tracking branch 'qatar/master'	11 years ago
float_dsp_neon.S	aarch64: Consistently use lowercase for vector element specifiers	1 year ago
neontest.h	all: Add missing header guards	9 years ago
timer.h	arm/aarch64: Use mach_absolute_time as timer on apple platforms	4 years ago
tx_float_init.c	lavu/tx: refactor to explicitly track and convert lookup table order	2 years ago
tx_float_neon.S	aarch64: Manually tweak vertical alignment/indentation in tx_float_neon.S	1 year ago