riscv/icsim.h

   1 #ifndef _RISCV_ICSIM_H
   2 #define _RISCV_ICSIM_H
   3
   4 // this file models a simple cache to estimate hit/miss rates.
   5 // it is currently unused.
   6
   7 #include <cstring>
   8 #include <string>
   9 #include <stdint.h>
  10
  11 class lfsr_t
  12 {
  13 public:
  14   lfsr_t() : reg(1) {}
  15   lfsr_t(const lfsr_t& lfsr) : reg(lfsr.reg) {}
  16   uint32_t next() { return reg = (reg>>1)^(-(reg&1) & 0xd0000001); }
  17 private:
  18   uint32_t reg;
  19 };
  20
  21 class icsim_t
  22 {
  23 public:
  24   icsim_t(size_t sets, size_t ways, size_t linesz, const char* name);
  25   icsim_t(const icsim_t& rhs);
  26   ~icsim_t();
  27
  28   void tick(uint64_t pc, int insnlen, bool store);
  29   void print_stats();
  30 private:
  31   lfsr_t lfsr;
  32
  33   size_t sets;
  34   size_t ways;
  35   size_t linesz;
  36   size_t idx_shift;
  37   size_t idx_mask;
  38
  39   uint64_t* tags;
  40
  41   uint64_t read_accesses;
  42   uint64_t read_misses;
  43   uint64_t bytes_read;
  44   uint64_t write_accesses;
  45   uint64_t write_misses;
  46   uint64_t bytes_written;
  47   uint64_t writebacks;
  48
  49   std::string name;
  50
  51   static const uint64_t VALID = 1ULL << 63;
  52   static const uint64_t DIRTY = 1ULL << 62;
  53 };
  54
  55 #endif