riscv/sv_decode.h

   1 // See LICENSE for license details.
   2
   3 #ifndef _RISCV_SV_DECODE_H
   4 #define _RISCV_SV_DECODE_H
   5
   6 #include "sv.h"
   7 #include "decode.h"
   8
   9 #define REG_RD 0x1
  10 #define REG_RS1 0x2
  11 #define REG_RS2 0x4
  12 #define REG_RS3 0x8
  13
  14 class sv_insn_t: public insn_t
  15 {
  16 public:
  17   sv_insn_t(insn_bits_t bits, unsigned int f) :
  18             insn_t(bits), fimap(f),
  19             cached_rd(0xff), cached_rs1(0xff),
  20             cached_rs2(0xff), cached_rs3(0xff),
  21             offs_rd(0), offs_rs1(0),
  22             offs_rs2(0), offs_rs3(0) {}
  23   uint64_t rd ()
  24     { return _remap(insn_t::rd (), fimap & REG_RD , offs_rd , cached_rd); }
  25   uint64_t rs1()
  26     { return _remap(insn_t::rs1(), fimap & REG_RS1, offs_rs1, cached_rs1); }
  27   uint64_t rs2()
  28     { return _remap(insn_t::rs2(), fimap & REG_RS2, offs_rs2, cached_rs2); }
  29   uint64_t rs3()
  30     { return _remap(insn_t::rs3(), fimap & REG_RS3, offs_rs3, cached_rs3); }
  31
  32   void reset_caches(void)
  33   {
  34     cached_rd = 0xff;
  35     cached_rs1 = 0xff;
  36     cached_rs2 = 0xff;
  37     cached_rs3 = 0xff;
  38   }
  39 private:
  40   unsigned int fimap;
  41   uint64_t cached_rd;
  42   uint64_t cached_rs1;
  43   uint64_t cached_rs2;
  44   uint64_t cached_rs3;
  45   int offs_rd;
  46   int offs_rs1;
  47   int offs_rs2;
  48   int offs_rs3;
  49   // remaps the register through the lookup table.
  50   // will need to take the current loop index/offset somehow
  51   uint64_t remap(uint64_t reg, bool isint, int &offs);
  52
  53   // cached version of remap: if remap is called multiple times
  54   // by an emulated instruction it would increment the loop offset
  55   // before it's supposed to.
  56   uint64_t _remap(uint64_t reg, bool isint, int &offs, uint64_t &cached)
  57   {
  58     if (cached == 0xff)
  59     {
  60         cached = remap(reg, isint, offs);
  61     }
  62     return cached;
  63   }
  64 };
  65
  66 #endif