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Diffstat (limited to '')
-rw-r--r-- | third_party/aom/aom_ports/aarch32_cpudetect.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/third_party/aom/aom_ports/aarch32_cpudetect.c b/third_party/aom/aom_ports/aarch32_cpudetect.c new file mode 100644 index 0000000000..753f957112 --- /dev/null +++ b/third_party/aom/aom_ports/aarch32_cpudetect.c @@ -0,0 +1,86 @@ +/* + * Copyright (c) 2023, Alliance for Open Media. All rights reserved + * + * This source code is subject to the terms of the BSD 2 Clause License and + * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License + * was not distributed with this source code in the LICENSE file, you can + * obtain it at www.aomedia.org/license/software. If the Alliance for Open + * Media Patent License 1.0 was not distributed with this source code in the + * PATENTS file, you can obtain it at www.aomedia.org/license/patent. + */ +// Feature detection code for Armv7-A / AArch32. + +#include "arm_cpudetect.h" + +#if !CONFIG_RUNTIME_CPU_DETECT + +static int arm_get_cpu_caps(void) { + // This function should actually be a no-op. There is no way to adjust any of + // these because the RTCD tables do not exist: the functions are called + // statically. + int flags = 0; +#if HAVE_NEON + flags |= HAS_NEON; +#endif // HAVE_NEON + return flags; +} + +#elif defined(_MSC_VER) // end !CONFIG_RUNTIME_CPU_DETECT + +static int arm_get_cpu_caps(void) { + int flags = 0; +#if HAVE_NEON + // MSVC has no inline __asm support for Arm, but it does let you __emit + // instructions via their assembled hex code. + // All of these instructions should be essentially nops. + __try { + // VORR q0,q0,q0 + __emit(0xF2200150); + flags |= HAS_NEON; + } __except (GetExceptionCode() == EXCEPTION_ILLEGAL_INSTRUCTION) { + // Ignore exception. + } +#endif // HAVE_NEON + return flags; +} + +#elif defined(ANDROID_USE_CPU_FEATURES_LIB) + +static int arm_get_cpu_caps(void) { + int flags = 0; +#if HAVE_NEON + uint64_t features = android_getCpuFeatures(); + if (features & ANDROID_CPU_ARM_FEATURE_NEON) flags |= HAS_NEON; +#endif // HAVE_NEON + return flags; +} + +#elif defined(__linux__) // end defined(AOM_USE_ANDROID_CPU_FEATURES) + +#include <sys/auxv.h> + +// Define hwcap values ourselves: building with an old auxv header where these +// hwcap values are not defined should not prevent features from being enabled. +#define AOM_AARCH32_HWCAP_NEON (1 << 12) + +static int arm_get_cpu_caps(void) { + int flags = 0; + unsigned long hwcap = getauxval(AT_HWCAP); +#if HAVE_NEON + if (hwcap & AOM_AARCH32_HWCAP_NEON) flags |= HAS_NEON; +#endif // HAVE_NEON + return flags; +} +#else // end __linux__ +#error \ + "Runtime CPU detection selected, but no CPU detection method " \ +"available for your platform. Rerun cmake with -DCONFIG_RUNTIME_CPU_DETECT=0." +#endif + +int aom_arm_cpu_caps(void) { + int flags = 0; + if (arm_cpu_env_flags(&flags)) { + return flags; + } + return arm_get_cpu_caps() & arm_cpu_env_mask(); +} |