Add advance logic for decode

2 files changed, 78 insertions, 56 deletions

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;