opencv

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#include "../../zbuild.h"
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#include "arm_features.h"
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#if defined(__linux__) && defined(HAVE_SYS_AUXV_H)
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#  include <sys/auxv.h>
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#  ifdef ARM_ASM_HWCAP
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#    include <asm/hwcap.h>
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#  endif
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#elif defined(__FreeBSD__) && defined(__aarch64__)
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#  include <machine/armreg.h>
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#  ifndef ID_AA64ISAR0_CRC32_VAL
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#    define ID_AA64ISAR0_CRC32_VAL ID_AA64ISAR0_CRC32
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#  endif
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#elif defined(__APPLE__)
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#  if !defined(_DARWIN_C_SOURCE)
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#    define _DARWIN_C_SOURCE /* enable types aliases (eg u_int) */
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#  endif
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#  include <sys/sysctl.h>
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#elif defined(_WIN32)
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#  include <windows.h>
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#endif
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static int arm_has_crc32() {
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#if defined(__linux__) && defined(ARM_AUXV_HAS_CRC32)
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#  ifdef HWCAP_CRC32
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    return (getauxval(AT_HWCAP) & HWCAP_CRC32) != 0 ? 1 : 0;
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#  else
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    return (getauxval(AT_HWCAP2) & HWCAP2_CRC32) != 0 ? 1 : 0;
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#  endif
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#elif defined(__FreeBSD__) && defined(__aarch64__)
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    return getenv("QEMU_EMULATING") == NULL
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      && ID_AA64ISAR0_CRC32_VAL(READ_SPECIALREG(id_aa64isar0_el1)) >= ID_AA64ISAR0_CRC32_BASE;
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#elif defined(__APPLE__)
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    int hascrc32;
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    size_t size = sizeof(hascrc32);
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    return sysctlbyname("hw.optional.armv8_crc32", &hascrc32, &size, NULL, 0) == 0
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      && hascrc32 == 1;
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#elif defined(_WIN32)
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    return IsProcessorFeaturePresent(PF_ARM_V8_CRC32_INSTRUCTIONS_AVAILABLE);
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#elif defined(ARM_NOCHECK_ACLE)
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    return 1;
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#else
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    return 0;
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#endif
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}
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/* AArch64 has neon. */
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#if !defined(__aarch64__) && !defined(_M_ARM64) && !defined(_M_ARM64EC)
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static inline int arm_has_neon() {
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#if defined(__linux__) && defined(ARM_AUXV_HAS_NEON)
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#  ifdef HWCAP_ARM_NEON
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    return (getauxval(AT_HWCAP) & HWCAP_ARM_NEON) != 0 ? 1 : 0;
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#  else
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    return (getauxval(AT_HWCAP) & HWCAP_NEON) != 0 ? 1 : 0;
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#  endif
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#elif defined(__APPLE__)
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    int hasneon;
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    size_t size = sizeof(hasneon);
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    return sysctlbyname("hw.optional.neon", &hasneon, &size, NULL, 0) == 0
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      && hasneon == 1;
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#elif defined(_M_ARM) && defined(WINAPI_FAMILY_PARTITION)
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#  if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_PHONE_APP)
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    return 1; /* Always supported */
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#  endif
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#endif
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#if defined(ARM_NOCHECK_NEON)
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    return 1;
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#else
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    return 0;
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#endif
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}
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#endif
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/* AArch64 does not have ARMv6 SIMD. */
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#if !defined(__aarch64__) && !defined(_M_ARM64) && !defined(_M_ARM64EC)
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static inline int arm_has_simd() {
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#if defined(__linux__) && defined(HAVE_SYS_AUXV_H)
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    const char *platform = (const char *)getauxval(AT_PLATFORM);
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    return strncmp(platform, "v6l", 3) == 0
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        || strncmp(platform, "v7l", 3) == 0
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        || strncmp(platform, "v8l", 3) == 0;
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#elif defined(ARM_NOCHECK_SIMD)
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    return 1;
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#else
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    return 0;
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#endif
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}
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#endif
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void Z_INTERNAL arm_check_features(struct arm_cpu_features *features) {
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#if defined(__aarch64__) || defined(_M_ARM64) || defined(_M_ARM64EC)
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    features->has_simd = 0; /* never available */
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    features->has_neon = 1; /* always available */
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#else
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    features->has_simd = arm_has_simd();
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    features->has_neon = arm_has_neon();
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#endif
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    features->has_crc32 = arm_has_crc32();
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}
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