mt/common/util.h

   1 // helpful utility and synch functions
   2
   3 // relies on defining "ncores" before including this file...
   4
   5 #ifndef __UTIL_H
   6 #define __UTIL_H
   7
   8 #define rdcycle() ({ unsigned long _c; asm volatile ("rdcycle %0" : "=r"(_c) :: "memory"); _c; })
   9 #define rdinstret() ({ unsigned long _c; asm volatile ("rdinstret %0" : "=r"(_c) :: "memory"); _c; })
  10
  11 void __attribute__((noinline)) barrier()
  12 {
  13   static volatile int sense;
  14   static volatile int count;
  15   static __thread int threadsense;
  16
  17   __sync_synchronize();
  18
  19   threadsense = !threadsense;
  20   if (__sync_fetch_and_add(&count, 1) == ncores-1)
  21   {
  22     count = 0;
  23     sense = threadsense;
  24   }
  25   else while(sense != threadsense)
  26     ;
  27
  28   __sync_synchronize();
  29 }
  30
  31 #endif //__UTIL_H
  32