1 files changed, 25 insertions, 0 deletions

diff --git a/nacl/cpucycles/amd64cpuspeed.c b/nacl/cpucycles/amd64cpuspeed.c
new file mode 100644
index 00000000..7e89511c
--- /dev/null
+++ b/nacl/cpucycles/amd64cpuspeed.c
@@ -0,0 +1,25 @@
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/sysctl.h>
+
+long long cpucycles_amd64cpuspeed(void)
+{
+  unsigned long long result;
+  asm volatile(".byte 15;.byte 49;shlq $32,%%rdx;orq %%rdx,%%rax"
+    : "=a" (result) ::  "%rdx");
+  return result;
+}
+
+long long cpucycles_amd64cpuspeed_persecond(void)
+{
+  int oid[2];
+  int val;
+  size_t size;
+  oid[0] = CTL_HW;
+  oid[1] = HW_CPUSPEED;
+  size = sizeof val;
+  if (sysctl(oid,2,&val,&size,0,0) == -1) return 0;
+  if (size != sizeof val) return 0;
+  return val * 1000000LL;
+}