1 files changed, 150 insertions, 0 deletions
diff --git a/media/libaom/src/aom_ports/arm_cpudetect.c b/media/libaom/src/aom_ports/arm_cpudetect.c
new file mode 100644
index 0000000000..5a75bb3484
--- /dev/null
+++ b/media/libaom/src/aom_ports/arm_cpudetect.c
@@ -0,0 +1,150 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include "aom_ports/arm.h"
+#include "config/aom_config.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("AOM_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("AOM_SIMD_CAPS_MASK");
+  return env && *env ? (int)strtol(env, NULL, 0) : ~0;
+}
+
+#if !CONFIG_RUNTIME_CPU_DETECT
+
+int aom_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
+  flags |= HAS_NEON;
+#endif /* HAVE_NEON */
+  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 aom_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
+  if (mask & HAS_NEON) {
+    __try {
+      /*VORR q0,q0,q0*/
+      __emit(0xF2200150);
+      flags |= HAS_NEON;
+    } __except (GetExceptionCode() == EXCEPTION_ILLEGAL_INSTRUCTION) {
+      /*Ignore exception.*/
+    }
+  }
+#endif /* HAVE_NEON */
+  return flags & mask;
+}
+
+#elif defined(__ANDROID__) /* end _MSC_VER */
+#include <cpu-features.h>
+
+int aom_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
+  if (features & ANDROID_CPU_ARM_FEATURE_NEON) flags |= HAS_NEON;
+#endif /* HAVE_NEON */
+  return flags & mask;
+}
+
+#elif defined(__linux__) /* end __ANDROID__ */
+
+#include <stdio.h>
+
+int aom_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
+      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 */
+    }
+    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