diff options
| -rw-r--r-- | inc/id.h | 21 | ||||
| -rw-r--r-- | inc/if.h | 2 | ||||
| -rw-r--r-- | src/sim/id.cc | 130 | ||||
| -rw-r--r-- | src/sim/if.cc | 4 |
4 files changed, 91 insertions, 66 deletions
@@ -17,6 +17,10 @@ class ID : public Stage Response advance(InstrDTO &next_instr, Response p) override; + /* The following methods are made public so that they may be tested, and are + * not to be called from outside classes during standard execution. + */ + /** * Parse an instruction into a type, opcode, and fields. If the type is * invalid, only the type field will be set. @@ -33,11 +37,6 @@ class ID : public Stage */ void get_instr_fields( signed int &s1, signed int &s2, signed int &s3, Mnemonic &m); - - /* The following methods are made public so that they may be tested, and are - * not to be called from outside classes during standard execution. - */ - /** * Facilitates register checkout and data hazard management. * It does this by checking that the register passed in is not currently @@ -57,11 +56,15 @@ class ID : public Stage void write_guard(signed int &r); private: - // TODO write me /** - * Helper for `` - * Attempts to parse and dereference instruction arguments. If a desc - + * Decodes `curr_instr` and sets status to BLOCKED if a data hazard occurs. + */ + void advance_helper(); + /** + * Helper for `get_instr_fields` + * Attempts to parse and dereference instruction arguments. Uses read and + * write guards to prevent RAW conflicts. + * * @param the resulting first field. To call this function properly, this * field must contain the section of the instruction to be parsed. * @param the resulting second field. @@ -25,7 +25,7 @@ class IF : public Stage * the nullptr. * @return STALLED if we are waiting on the storage devices, OK otherwise. */ - void fetch_with_buffer(); + void advance_helper(); }; #endif /* IF_H_INCLUDED */ diff --git a/src/sim/id.cc b/src/sim/id.cc index c04b31f..68ac555 100644 --- a/src/sim/id.cc +++ b/src/sim/id.cc @@ -5,68 +5,26 @@ #include "logger.h" #include "response.h" #include "stage.h" -#include <algorithm> ID::ID(Stage *stage) : Stage(stage) { this->id = DCDE; } Response ID::advance(InstrDTO &next_instr, Response p) { - Response r; - signed int s1, s2, s3; - Mnemonic m; - - s1 = next_instr.get_instr_bits(); - - get_instr_fields(s1, s2, s3, m); - return r; -} - -void ID::decode_R_type(signed int &s1, signed int &s2, signed int &s3) -{ - unsigned int s0b, s1b, s2b; - Response r1, r2; - - s0b = REG_SIZE; - s1b = s0b + REG_SIZE; - s2b = s1b + REG_SIZE; - s3 = GET_MID_BITS(s1, s1b, s2b); - s2 = GET_MID_BITS(s1, s0b, s1b); - s1 = GET_LS_BITS(s1, s0b); - - r1 = this->read_guard(s1); - r2 = this->read_guard(s2); - this->write_guard(s3); - - this->status = std::max(r1, r2); -} -void ID::decode_I_type(signed int &s1, signed int &s2, signed int &s3) -{ - unsigned int s0b, s1b, s2b; - - s0b = REG_SIZE; - s1b = s0b + REG_SIZE; - s2b = WORD_SPEC; - s3 = GET_MID_BITS(s1, s1b, s2b); - s2 = GET_MID_BITS(s1, s0b, s1b); - s1 = GET_LS_BITS(s1, s0b); - - this->status = this->read_guard(s1); - this->write_guard(s2); -} - -void ID::decode_J_type(signed int &s1, signed int &s2) -{ - unsigned int s0b, s1b; - - s0b = REG_SIZE; - s1b = WORD_SPEC; - s2 = GET_MID_BITS(s1, s0b, s1b); - s1 = GET_LS_BITS(s1, s0b); + Response n; + + this->advance_helper(); + if (this->status == OK && p == OK) { + // mutual consent + this->curr_instr->set_time_of(this->id, this->clock_cycle); + next_instr = *this->curr_instr; + curr_instr = nullptr; + } - this->status = this->read_guard(*&s1); + n = (p != OK || this->status != OK) ? BLOCKED : OK; + // the power of consent + n = this->next->advance(next_instr, n); } -// TODO this function is ugly void ID::get_instr_fields( signed int &s1, signed int &s2, signed int &s3, Mnemonic &m) { @@ -119,3 +77,67 @@ void ID::write_guard(signed int &v) this->checked_out.push_back(v); v = this->dereference_register(v); } + +void ID::advance_helper() +{ + signed int s1, s2, s3; + Mnemonic m; + + // it may be good to ensure we are not doing + // work that has already been done + if (this->curr_instr) { + s1 = curr_instr->get_instr_bits(); + get_instr_fields(s1, s2, s3, m); + if (this->status == OK) { + curr_instr->set_s1(s1); + curr_instr->set_s2(s2); + curr_instr->set_s3(s3); + curr_instr->set_mnemonic(m); + } + } +} + +void ID::decode_R_type(signed int &s1, signed int &s2, signed int &s3) +{ + unsigned int s0b, s1b, s2b; + Response r1, r2; + + s0b = REG_SIZE; + s1b = s0b + REG_SIZE; + s2b = s1b + REG_SIZE; + s3 = GET_MID_BITS(s1, s1b, s2b); + s2 = GET_MID_BITS(s1, s0b, s1b); + s1 = GET_LS_BITS(s1, s0b); + + r1 = this->read_guard(s1); + r2 = this->read_guard(s2); + this->write_guard(s3); + + this->status = (r1 == BLOCKED || r2 == BLOCKED) ? BLOCKED : OK; +} +void ID::decode_I_type(signed int &s1, signed int &s2, signed int &s3) +{ + unsigned int s0b, s1b, s2b; + + s0b = REG_SIZE; + s1b = s0b + REG_SIZE; + s2b = WORD_SPEC; + s3 = GET_MID_BITS(s1, s1b, s2b); + s2 = GET_MID_BITS(s1, s0b, s1b); + s1 = GET_LS_BITS(s1, s0b); + + this->status = this->read_guard(s1); + this->write_guard(s2); +} + +void ID::decode_J_type(signed int &s1, signed int &s2) +{ + unsigned int s0b, s1b; + + s0b = REG_SIZE; + s1b = WORD_SPEC; + s2 = GET_MID_BITS(s1, s0b, s1b); + s1 = GET_LS_BITS(s1, s0b); + + this->status = this->read_guard(*&s1); +} diff --git a/src/sim/if.cc b/src/sim/if.cc index de044f8..7d3291b 100644 --- a/src/sim/if.cc +++ b/src/sim/if.cc @@ -8,7 +8,7 @@ IF::IF(Stage *stage) : Stage(stage) { this->id = FETCH; } Response IF::advance(InstrDTO &next_instr, Response p) { - this->fetch_with_buffer(); + this->advance_helper(); if (this->status == OK && p == OK) { // mutual consent ++this->pc; @@ -19,7 +19,7 @@ Response IF::advance(InstrDTO &next_instr, Response p) return this->status; } -void IF::fetch_with_buffer() +void IF::advance_helper() { Response r; signed int bits; |