diff options
Diffstat (limited to 'media/ffvpx/libavutil/aarch64/cpu.c')
| -rw-r--r-- | media/ffvpx/libavutil/aarch64/cpu.c | 30 |
1 files changed, 8 insertions, 22 deletions
diff --git a/media/ffvpx/libavutil/aarch64/cpu.c b/media/ffvpx/libavutil/aarch64/cpu.c index f27fef3992..7a05391343 100644 --- a/media/ffvpx/libavutil/aarch64/cpu.c +++ b/media/ffvpx/libavutil/aarch64/cpu.c @@ -24,34 +24,20 @@ #include <stdint.h> #include <sys/auxv.h> -#define get_cpu_feature_reg(reg, val) \ - __asm__("mrs %0, " #reg : "=r" (val)) +#define HWCAP_AARCH64_ASIMDDP (1 << 20) +#define HWCAP2_AARCH64_I8MM (1 << 13) static int detect_flags(void) { int flags = 0; -#if defined(HWCAP_CPUID) && HAVE_INLINE_ASM unsigned long hwcap = getauxval(AT_HWCAP); - // We can check for DOTPROD and I8MM using HWCAP_ASIMDDP and - // HWCAP2_I8MM too, avoiding to read the CPUID registers (which triggers - // a trap, handled by the kernel). However the HWCAP_* defines for these - // extensions are added much later than HWCAP_CPUID, so the userland - // headers might lack support for them even if the binary later is run - // on hardware that does support it (and where the kernel might support - // HWCAP_CPUID). - // See https://www.kernel.org/doc/html/latest/arm64/cpu-feature-registers.html - if (hwcap & HWCAP_CPUID) { - uint64_t tmp; - - get_cpu_feature_reg(ID_AA64ISAR0_EL1, tmp); - if (((tmp >> 44) & 0xf) == 0x1) - flags |= AV_CPU_FLAG_DOTPROD; - get_cpu_feature_reg(ID_AA64ISAR1_EL1, tmp); - if (((tmp >> 52) & 0xf) == 0x1) - flags |= AV_CPU_FLAG_I8MM; - } -#endif + unsigned long hwcap2 = getauxval(AT_HWCAP2); + + if (hwcap & HWCAP_AARCH64_ASIMDDP) + flags |= AV_CPU_FLAG_DOTPROD; + if (hwcap2 & HWCAP2_AARCH64_I8MM) + flags |= AV_CPU_FLAG_I8MM; return flags; } |