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diff --git a/media/libyuv/source/cpu_id.cc b/media/libyuv/source/cpu_id.cc
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+/*
+ * Copyright 2011 The LibYuv 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 "libyuv/cpu_id.h"
+
+#if defined(_MSC_VER)
+#include <intrin.h> // For __cpuidex()
+#endif
+#if !defined(__pnacl__) && !defined(__CLR_VER) && \
+ !defined(__native_client__) && (defined(_M_IX86) || defined(_M_X64)) && \
+ defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219)
+#include <immintrin.h> // For _xgetbv()
+#endif
+
+#if !defined(__native_client__)
+#include <stdlib.h> // For getenv()
+#endif
+
+// For ArmCpuCaps() but unittested on all platforms
+#include <stdio.h>
+#include <string.h>
+
+#include "libyuv/basic_types.h" // For CPU_X86
+
+#ifdef __cplusplus
+namespace libyuv {
+extern "C" {
+#endif
+
+// For functions that use the stack and have runtime checks for overflow,
+// use SAFEBUFFERS to avoid additional check.
+#if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219) && \
+ !defined(__clang__)
+#define SAFEBUFFERS __declspec(safebuffers)
+#else
+#define SAFEBUFFERS
+#endif
+
+// Low level cpuid for X86.
+#if (defined(_M_IX86) || defined(_M_X64) || \
+ defined(__i386__) || defined(__x86_64__)) && \
+ !defined(__pnacl__) && !defined(__CLR_VER)
+LIBYUV_API
+void CpuId(uint32 info_eax, uint32 info_ecx, uint32* cpu_info) {
+#if defined(_MSC_VER)
+// Visual C version uses intrinsic or inline x86 assembly.
+#if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219)
+ __cpuidex((int*)(cpu_info), info_eax, info_ecx);
+#elif defined(_M_IX86)
+ __asm {
+ mov eax, info_eax
+ mov ecx, info_ecx
+ mov edi, cpu_info
+ cpuid
+ mov [edi], eax
+ mov [edi + 4], ebx
+ mov [edi + 8], ecx
+ mov [edi + 12], edx
+ }
+#else // Visual C but not x86
+ if (info_ecx == 0) {
+ __cpuid((int*)(cpu_info), info_eax);
+ } else {
+ cpu_info[3] = cpu_info[2] = cpu_info[1] = cpu_info[0] = 0;
+ }
+#endif
+// GCC version uses inline x86 assembly.
+#else // defined(_MSC_VER)
+ uint32 info_ebx, info_edx;
+ asm volatile (
+#if defined( __i386__) && defined(__PIC__)
+ // Preserve ebx for fpic 32 bit.
+ "mov %%ebx, %%edi \n"
+ "cpuid \n"
+ "xchg %%edi, %%ebx \n"
+ : "=D" (info_ebx),
+#else
+ "cpuid \n"
+ : "=b" (info_ebx),
+#endif // defined( __i386__) && defined(__PIC__)
+ "+a" (info_eax), "+c" (info_ecx), "=d" (info_edx));
+ cpu_info[0] = info_eax;
+ cpu_info[1] = info_ebx;
+ cpu_info[2] = info_ecx;
+ cpu_info[3] = info_edx;
+#endif // defined(_MSC_VER)
+}
+#else // (defined(_M_IX86) || defined(_M_X64) ...
+LIBYUV_API
+void CpuId(uint32 eax, uint32 ecx, uint32* cpu_info) {
+ cpu_info[0] = cpu_info[1] = cpu_info[2] = cpu_info[3] = 0;
+}
+#endif
+
+// For VS2010 and earlier emit can be used:
+// _asm _emit 0x0f _asm _emit 0x01 _asm _emit 0xd0 // For VS2010 and earlier.
+// __asm {
+// xor ecx, ecx // xcr 0
+// xgetbv
+// mov xcr0, eax
+// }
+// For VS2013 and earlier 32 bit, the _xgetbv(0) optimizer produces bad code.
+// https://code.google.com/p/libyuv/issues/detail?id=529
+#if defined(_M_IX86) && (_MSC_VER < 1900)
+#pragma optimize("g", off)
+#endif
+#if (defined(_M_IX86) || defined(_M_X64) || \
+ defined(__i386__) || defined(__x86_64__)) && \
+ !defined(__pnacl__) && !defined(__CLR_VER) && !defined(__native_client__)
+#define HAS_XGETBV
+// X86 CPUs have xgetbv to detect OS saves high parts of ymm registers.
+int GetXCR0() {
+ uint32 xcr0 = 0u;
+#if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219)
+ xcr0 = (uint32)(_xgetbv(0)); // VS2010 SP1 required.
+#elif defined(__i386__) || defined(__x86_64__)
+ asm(".byte 0x0f, 0x01, 0xd0" : "=a" (xcr0) : "c" (0) : "%edx");
+#endif // defined(__i386__) || defined(__x86_64__)
+ return xcr0;
+}
+#endif // defined(_M_IX86) || defined(_M_X64) ..
+// Return optimization to previous setting.
+#if defined(_M_IX86) && (_MSC_VER < 1900)
+#pragma optimize("g", on)
+#endif
+
+// based on libvpx arm_cpudetect.c
+// For Arm, but public to allow testing on any CPU
+LIBYUV_API SAFEBUFFERS
+int ArmCpuCaps(const char* cpuinfo_name) {
+ char cpuinfo_line[512];
+ FILE* f = fopen(cpuinfo_name, "r");
+ if (!f) {
+ // Assume Neon if /proc/cpuinfo is unavailable.
+ // This will occur for Chrome sandbox for Pepper or Render process.
+ return kCpuHasNEON;
+ }
+ while (fgets(cpuinfo_line, sizeof(cpuinfo_line) - 1, f)) {
+ if (memcmp(cpuinfo_line, "Features", 8) == 0) {
+ char* p = strstr(cpuinfo_line, " neon");
+ if (p && (p[5] == ' ' || p[5] == '\n')) {
+ fclose(f);
+ return kCpuHasNEON;
+ }
+ // aarch64 uses asimd for Neon.
+ p = strstr(cpuinfo_line, " asimd");
+ if (p && (p[6] == ' ' || p[6] == '\n')) {
+ fclose(f);
+ return kCpuHasNEON;
+ }
+ }
+ }
+ fclose(f);
+ return 0;
+}
+
+// CPU detect function for SIMD instruction sets.
+LIBYUV_API
+int cpu_info_ = 0; // cpu_info is not initialized yet.
+
+// Test environment variable for disabling CPU features. Any non-zero value
+// to disable. Zero ignored to make it easy to set the variable on/off.
+#if !defined(__native_client__) && !defined(_M_ARM)
+
+static LIBYUV_BOOL TestEnv(const char* name) {
+ const char* var = getenv(name);
+ if (var) {
+ if (var[0] != '0') {
+ return LIBYUV_TRUE;
+ }
+ }
+ return LIBYUV_FALSE;
+}
+#else // nacl does not support getenv().
+static LIBYUV_BOOL TestEnv(const char*) {
+ return LIBYUV_FALSE;
+}
+#endif
+
+LIBYUV_API SAFEBUFFERS
+int InitCpuFlags(void) {
+ // TODO(fbarchard): swap kCpuInit logic so 0 means uninitialized.
+ int cpu_info = 0;
+#if !defined(__pnacl__) && !defined(__CLR_VER) && defined(CPU_X86)
+ uint32 cpu_info0[4] = { 0, 0, 0, 0 };
+ uint32 cpu_info1[4] = { 0, 0, 0, 0 };
+ uint32 cpu_info7[4] = { 0, 0, 0, 0 };
+ CpuId(0, 0, cpu_info0);
+ CpuId(1, 0, cpu_info1);
+ if (cpu_info0[0] >= 7) {
+ CpuId(7, 0, cpu_info7);
+ }
+ cpu_info = ((cpu_info1[3] & 0x04000000) ? kCpuHasSSE2 : 0) |
+ ((cpu_info1[2] & 0x00000200) ? kCpuHasSSSE3 : 0) |
+ ((cpu_info1[2] & 0x00080000) ? kCpuHasSSE41 : 0) |
+ ((cpu_info1[2] & 0x00100000) ? kCpuHasSSE42 : 0) |
+ ((cpu_info7[1] & 0x00000200) ? kCpuHasERMS : 0) |
+ ((cpu_info1[2] & 0x00001000) ? kCpuHasFMA3 : 0) |
+ kCpuHasX86;
+
+#ifdef HAS_XGETBV
+ // AVX requires CPU has AVX, XSAVE and OSXSave for xgetbv
+ if (((cpu_info1[2] & 0x1c000000) == 0x1c000000) && // AVX and OSXSave
+ ((GetXCR0() & 6) == 6)) { // Test OS saves YMM registers
+ cpu_info |= ((cpu_info7[1] & 0x00000020) ? kCpuHasAVX2 : 0) | kCpuHasAVX;
+
+ // Detect AVX512bw
+ if ((GetXCR0() & 0xe0) == 0xe0) {
+ cpu_info |= (cpu_info7[1] & 0x40000000) ? kCpuHasAVX3 : 0;
+ }
+ }
+#endif
+
+ // Environment variable overrides for testing.
+ if (TestEnv("LIBYUV_DISABLE_X86")) {
+ cpu_info &= ~kCpuHasX86;
+ }
+ if (TestEnv("LIBYUV_DISABLE_SSE2")) {
+ cpu_info &= ~kCpuHasSSE2;
+ }
+ if (TestEnv("LIBYUV_DISABLE_SSSE3")) {
+ cpu_info &= ~kCpuHasSSSE3;
+ }
+ if (TestEnv("LIBYUV_DISABLE_SSE41")) {
+ cpu_info &= ~kCpuHasSSE41;
+ }
+ if (TestEnv("LIBYUV_DISABLE_SSE42")) {
+ cpu_info &= ~kCpuHasSSE42;
+ }
+ if (TestEnv("LIBYUV_DISABLE_AVX")) {
+ cpu_info &= ~kCpuHasAVX;
+ }
+ if (TestEnv("LIBYUV_DISABLE_AVX2")) {
+ cpu_info &= ~kCpuHasAVX2;
+ }
+ if (TestEnv("LIBYUV_DISABLE_ERMS")) {
+ cpu_info &= ~kCpuHasERMS;
+ }
+ if (TestEnv("LIBYUV_DISABLE_FMA3")) {
+ cpu_info &= ~kCpuHasFMA3;
+ }
+ if (TestEnv("LIBYUV_DISABLE_AVX3")) {
+ cpu_info &= ~kCpuHasAVX3;
+ }
+#endif
+#if defined(__mips__) && defined(__linux__)
+#if defined(__mips_dspr2)
+ cpu_info |= kCpuHasDSPR2;
+#endif
+ cpu_info |= kCpuHasMIPS;
+ if (getenv("LIBYUV_DISABLE_DSPR2")) {
+ cpu_info &= ~kCpuHasDSPR2;
+ }
+#endif
+#if defined(__arm__) || defined(__aarch64__)
+// gcc -mfpu=neon defines __ARM_NEON__
+// __ARM_NEON__ generates code that requires Neon. NaCL also requires Neon.
+// For Linux, /proc/cpuinfo can be tested but without that assume Neon.
+#if defined(__ARM_NEON__) || defined(__native_client__) || !defined(__linux__)
+ cpu_info = kCpuHasNEON;
+// For aarch64(arm64), /proc/cpuinfo's feature is not complete, e.g. no neon
+// flag in it.
+// So for aarch64, neon enabling is hard coded here.
+#endif
+#if defined(__aarch64__)
+ cpu_info = kCpuHasNEON;
+#else
+ // Linux arm parse text file for neon detect.
+ cpu_info = ArmCpuCaps("/proc/cpuinfo");
+#endif
+ cpu_info |= kCpuHasARM;
+ if (TestEnv("LIBYUV_DISABLE_NEON")) {
+ cpu_info &= ~kCpuHasNEON;
+ }
+#endif // __arm__
+ if (TestEnv("LIBYUV_DISABLE_ASM")) {
+ cpu_info = 0;
+ }
+ cpu_info |= kCpuInitialized;
+ cpu_info_ = cpu_info;
+ return cpu_info;
+}
+
+// Note that use of this function is not thread safe.
+LIBYUV_API
+void MaskCpuFlags(int enable_flags) {
+ cpu_info_ = InitCpuFlags() & enable_flags;
+}
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace libyuv
+#endif
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