cpu/beta_cpu/btb.hh

   1 #ifndef __BTB_HH__
   2 #define __BTB_HH__
   3
   4 // For Addr type.
   5 #include "arch/alpha/isa_traits.hh"
   6
   7 class DefaultBTB
   8 {
   9   private:
  10     struct BTBEntry
  11     {
  12         BTBEntry()
  13             : tag(0), target(0), valid(false)
  14         {
  15         }
  16
  17         Addr tag;
  18         Addr target;
  19         bool valid;
  20     };
  21
  22   public:
  23     DefaultBTB(unsigned numEntries, unsigned tagBits,
  24                unsigned instShiftAmt);
  25
  26     Addr lookup(const Addr &inst_PC);
  27
  28     bool valid(const Addr &inst_PC);
  29
  30     void update(const Addr &inst_PC, const Addr &target_PC);
  31
  32   private:
  33     inline unsigned getIndex(const Addr &inst_PC);
  34
  35     inline Addr getTag(const Addr &inst_PC);
  36
  37     BTBEntry *btb;
  38
  39     unsigned numEntries;
  40
  41     unsigned idxMask;
  42
  43     unsigned tagBits;
  44
  45     unsigned tagMask;
  46
  47     unsigned instShiftAmt;
  48
  49     unsigned tagShiftAmt;
  50 };
  51
  52 #endif // __BTB_HH__