ref: cf35ffc025086588db5ccab977a94a325a50f949
dir: /vpx_ports/arm_cpudetect.c/
/* * Copyright (c) 2010 The WebM project authors. All Rights Reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be found * in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ #include <stdlib.h> #include <string.h> #include "./vpx_config.h" #include "vpx_ports/arm.h" #ifdef WINAPI_FAMILY #include <winapifamily.h> #if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP) #define getenv(x) NULL #endif #endif static int arm_cpu_env_flags(int *flags) { char *env; env = getenv("VPX_SIMD_CAPS"); if (env && *env) { *flags = (int)strtol(env, NULL, 0); return 0; } *flags = 0; return -1; } static int arm_cpu_env_mask(void) { char *env; env = getenv("VPX_SIMD_CAPS_MASK"); return env && *env ? (int)strtol(env, NULL, 0) : ~0; } #if !CONFIG_RUNTIME_CPU_DETECT int arm_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; int mask; if (!arm_cpu_env_flags(&flags)) { return flags; } mask = arm_cpu_env_mask(); #if HAVE_NEON || HAVE_NEON_ASM flags |= HAS_NEON; #endif /* HAVE_NEON || HAVE_NEON_ASM */ return flags & mask; } #elif defined(_MSC_VER) /* end !CONFIG_RUNTIME_CPU_DETECT */ /*For GetExceptionCode() and EXCEPTION_ILLEGAL_INSTRUCTION.*/ #define WIN32_LEAN_AND_MEAN #define WIN32_EXTRA_LEAN #include <windows.h> int arm_cpu_caps(void) { int flags; int mask; if (!arm_cpu_env_flags(&flags)) { return flags; } mask = arm_cpu_env_mask(); /* 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. */ #if HAVE_NEON || HAVE_NEON_ASM if (mask & HAS_NEON) { __try { /*VORR q0,q0,q0*/ __emit(0xF2200150); flags |= HAS_NEON; } __except (GetExceptionCode() == EXCEPTION_ILLEGAL_INSTRUCTION) { /*Ignore exception.*/ } } #endif /* HAVE_NEON || HAVE_NEON_ASM */ return flags & mask; } #elif defined(__ANDROID__) /* end _MSC_VER */ #include <cpu-features.h> int arm_cpu_caps(void) { int flags; int mask; uint64_t features; if (!arm_cpu_env_flags(&flags)) { return flags; } mask = arm_cpu_env_mask(); features = android_getCpuFeatures(); #if HAVE_NEON || HAVE_NEON_ASM if (features & ANDROID_CPU_ARM_FEATURE_NEON) flags |= HAS_NEON; #endif /* HAVE_NEON || HAVE_NEON_ASM */ return flags & mask; } #elif defined(__linux__) /* end __ANDROID__ */ #include <stdio.h> int arm_cpu_caps(void) { FILE *fin; int flags; int mask; if (!arm_cpu_env_flags(&flags)) { return flags; } mask = arm_cpu_env_mask(); /* Reading /proc/self/auxv would be easier, but that doesn't work reliably * on Android. * This also means that detection will fail in Scratchbox. */ fin = fopen("/proc/cpuinfo", "r"); if (fin != NULL) { /* 512 should be enough for anybody (it's even enough for all the flags * that x86 has accumulated... so far). */ char buf[512]; while (fgets(buf, 511, fin) != NULL) { #if HAVE_NEON || HAVE_NEON_ASM if (memcmp(buf, "Features", 8) == 0) { char *p; p = strstr(buf, " neon"); if (p != NULL && (p[5] == ' ' || p[5] == '\n')) { flags |= HAS_NEON; } } #endif /* HAVE_NEON || HAVE_NEON_ASM */ } fclose(fin); } return flags & mask; } #else /* end __linux__ */ #error \ "--enable-runtime-cpu-detect selected, but no CPU detection method " \ "available for your platform. Reconfigure with --disable-runtime-cpu-detect." #endif