Update common_arm64.h

Author: martin-frbg

common_arm64.h

@@ -78,7 +78,17 @@ static void __inline blas_lock(volatile BLASULONG *address){
 
 #define BLAS_LOCK_DEFINED
 
+static __inline BLASULONG rpcc(void){
+  BLASULONG ret = 0;
+ 
+  __asm__ __volatile__ ("mrs %0,cntvct_el0":"=r"(ret));
 
+  return ret;
+}
+
+#define RPCC_DEFINED
+#define RPCC64BIT
+ 
 
 static inline int blas_quickdivide(blasint x, blasint y){
   return x / y;