diff options
| -rw-r--r-- | inc/id.h | 9 | ||||
| -rw-r--r-- | src/id.cc | 27 |
2 files changed, 18 insertions, 18 deletions
@@ -60,7 +60,7 @@ class ID : public Stage * @param the resulting third field, which varies per type. * @param the resulting mnemonic. */ - void get_instr_fields(signed int &s1); + void get_instr_fields(signed int instr_bits); void decode_R_type(signed int &s1); void decode_I_type(signed int &s1); void decode_J_type(signed int &s1); @@ -96,10 +96,11 @@ class ID : public Stage /** * Facilitates register checkout and data hazard management. * It does this by checking that the register passed in is not currently - * checked out. If true, then replaces reg with the value of the register and - * returns OK. If false, returns STALLED. + * checked out. If true, then sets `result' with the value of the register + * and returns OK. If false, returns STALLED. * - * @param the registers number, to be dereferenced. + * @param the registers number + * @param the dereferenced register value * @return OK if `reg` is not checked out, STALLED otherwise. */ template <typename T> Response read_guard(int reg, T &result) @@ -24,37 +24,35 @@ void ID::advance_helper() { - signed int s1; - if (this->curr_instr->mnemonic == NOP) this->status = OK; else { // instuction in bits in s1 - s1 = this->curr_instr->slot_A; - get_instr_fields(s1); + get_instr_fields(this->curr_instr->slot_A); } } -void ID::get_instr_fields(signed int &s1) +void ID::get_instr_fields(signed int instr_bits) { unsigned int type; Mnemonic m; - this->split_instr(s1, type, m); + this->split_instr(instr_bits, type, m); this->curr_instr->mnemonic = m; switch (type) { case 0b00: - this->decode_R_type(s1); + this->decode_R_type(instr_bits); break; case 0b01: - this->decode_I_type(s1); + this->decode_I_type(instr_bits); break; case 0b10: - this->decode_J_type(s1); + this->decode_J_type(instr_bits); break; case 0b11: - // not defined, m = NOP + this->curr_instr->mnemonic = NOP; this->status = OK; } + } void ID::split_instr(signed int &raw, unsigned int &type, Mnemonic &m) @@ -233,9 +231,10 @@ void ID::decode_J_type(signed int &s1) s2 = s1; // source s3 = 2; // stack pointer s1 = -1; // increment amount - r1 = this->read_guard<signed int>(s2, s2); + this->curr_instr->operands.integer.slot_one = s1; - this->curr_instr->operands.integer.slot_two = s2; + r1 = this->read_guard<signed int>( + s2, this->curr_instr->operands.integer.slot_two); r2 = (this->is_checked_out(s3)) ? STALLED : OK; // we read the stack pointer if (r1 == OK && r2 == OK) { @@ -265,9 +264,9 @@ void ID::decode_J_type(signed int &s1) s1 = 1; // link register [[fallthrough]]; default: - this->status = this->read_guard<signed int>(s1, s1); + this->status = this->read_guard<signed int>( + s1, this->curr_instr->operands.integer.slot_one); if (this->status == OK) { - this->curr_instr->operands.integer.slot_one = s1; this->curr_instr->operands.integer.slot_two = s2; this->curr_instr->operands.integer.slot_three = s3; } |