1 files changed, 53 insertions, 0 deletions
diff --git a/vpx_ports/riscv_cpudetect.c b/vpx_ports/riscv_cpudetect.c
new file mode 100644
index 000000000..830b18869
--- /dev/null
+++ b/vpx_ports/riscv_cpudetect.c
@@ -0,0 +1,53 @@
+/*
+ *  Copyright (c) 2017 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 <fcntl.h>
+#include <unistd.h>
+#include <stdint.h>
+
+#include "./vpx_config.h"
+#include "vpx_ports/riscv.h"
+
+#if CONFIG_RUNTIME_CPU_DETECT
+static int 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 cpu_env_mask(void) {
+  char *env;
+  env = getenv("VPX_SIMD_CAPS_MASK");
+  return env && *env ? (int)strtol(env, NULL, 0) : ~0;
+}
+
+int riscv_cpu_caps(void) {
+  int flags = HAS_RVV;
+  int mask;
+
+  // If VPX_SIMD_CAPS is set then allow only those capabilities.
+  if (!cpu_env_flags(&flags)) {
+    return flags;
+  }
+
+  mask = cpu_env_mask();
+
+  return flags & mask;
+}
+#else
+// If there is no RTCD the function pointers are not used and can not be
+// changed.
+int riscv_cpu_caps(void) { return 0; }
+#endif  // CONFIG_RUNTIME_CPU_DETECT