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#include "id.h"
#include "accessor.h"
#include "instr.h"
#include "instrDTO.h"
#include "logger.h"
#include "response.h"
#include "stage.h"
ID::ID(Stage *stage) : Stage(stage) { this->id = DCDE; }
Response ID::advance(InstrDTO &i)
{
Response r;
signed int s1, s2, s3;
Mnemonic m;
s1 = i.get_instr_bits();
get_instr_fields(s1, s2, s3, m);
return r;
}
// TODO this function is ugly
void ID::get_instr_fields(
signed int &s1, signed int &s2, signed int &s3, Mnemonic &m)
{
unsigned int type, s0b, s1b, s2b;
this->split_instr(s1, type, m);
// define the parsing bounds
s0b = REG_SIZE;
switch (type) {
case 0b00:
// R-TYPE
s1b = s0b + REG_SIZE;
s2b = s1b + REG_SIZE;
break;
case 0b01:
// I-TYPE
s1b = s0b + REG_SIZE;
s2b = WORD_SPEC;
break;
case 0b10:
// J-TYPE
s1b = WORD_SPEC;
}
if (type != 0b10)
s3 = GET_MID_BITS(s1, s1b, s2b);
s2 = GET_MID_BITS(s1, s0b, s1b);
s1 = GET_LS_BITS(s1, s0b);
}
void ID::split_instr(signed int &raw, unsigned int &type, Mnemonic &m)
{
unsigned int opcode, opcode_size;
type = GET_LS_BITS(raw, TYPE_SIZE);
opcode_size = (type == 0b0) ? R_OPCODE_SIZE : OPCODE_SIZE;
opcode = GET_MID_BITS(raw, TYPE_SIZE, TYPE_SIZE + opcode_size);
try {
m = instr::mnemonic_map.at((opcode << TYPE_SIZE) + type);
} catch (std::out_of_range const &) {
m = NOP;
}
raw = (unsigned int)raw >> (TYPE_SIZE + opcode_size);
}
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