Merge pull request #2467 from AGSaidi/rpcc

Make rpcc() on arm64 get closer to what x86 returns

Author: martin-frbg

common_arm64.h

@@ -81,10 +81,12 @@ static void __inline blas_lock(volatile BLASULONG *address){
 #if !defined(OS_DARWIN) && !defined (OS_ANDROID)
 static __inline BLASULONG rpcc(void){
   BLASULONG ret = 0;
+  blasint shift;
 
   __asm__ __volatile__ ("isb; mrs %0,cntvct_el0":"=r"(ret));
+  __asm__ __volatile__ ("mrs %0,cntfrq_el0; clz %w0, %w0":"=&r"(shift));
 
-  return ret;
+  return ret << shift;
 }
 
 #define RPCC_DEFINED