Merge pull request #37 from bdunahu/bdunahu

Instr, InstrDTO gets/sets, other structures required for decode

-- tests as we move forward
-- base classes
-- decode stage implemented

1 files changed, 25 insertions, 8 deletions

diff --git a/src/sim/if.cc b/src/sim/if.cc
index deed8e1..7d3291b 100644
--- a/src/sim/if.cc
+++ b/src/sim/if.cc
@@ -2,18 +2,35 @@
 #include "accessor.h"
 #include "instrDTO.h"
 #include "response.h"
+#include "stage.h"
 
-Response IF::advance(InstrDTO &i)
+IF::IF(Stage *stage) : Stage(stage) { this->id = FETCH; }
+
+Response IF::advance(InstrDTO &next_instr, Response p)
+{
+	this->advance_helper();
+	if (this->status == OK && p == OK) {
+		// mutual consent
+		++this->pc;
+		this->curr_instr->set_time_of(this->id, this->clock_cycle);
+		next_instr = *this->curr_instr;
+		curr_instr = nullptr;
+	}
+	return this->status;
+}
+
+void IF::advance_helper()
 {
 	Response r;
 	signed int bits;
 
-	r = this->storage->read_word(this->id, this->pc, bits);
-	if (r == OK) {
-		++this->pc;
-		i.set_if_cycle(this->clock_cycle);
-		i.set_instr_bits(bits);
+	if (this->curr_instr == nullptr) {
+		r = this->storage->read_word(this->id, this->pc, bits);
+		if (r == OK) {
+			this->status = r;
+			this->curr_instr = std::make_unique<InstrDTO>();
+			this->curr_instr->set_instr_bits(bits);
+		} else
+			this->status = STALLED;
 	}
-
-	return r;
 }