1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
#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; }
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);
}
Response ID::read_guard(signed int &v)
{
Response r;
if (this->is_checked_out(v))
r = STALLED;
else {
r = OK;
v = this->dereference_register(v);
}
return r;
}
void ID::write_guard(signed int &v)
{
// zero register shouldn't be written.
if (v != 0) {
// keep track in the instrDTO for displaying to user and writeback
// keep track in checked_out so we can still access this information!
this->checked_out.push_back(v);
this->curr_instr->set_checked_out(v);
}
v = this->dereference_register(v);
}
void ID::advance_helper()
{
signed int s1, s2, s3;
Mnemonic m;
Type t;
if (curr_instr->get_mnemonic() == NOP)
this->status = OK;
else {
s1 = curr_instr->get_instr_bits();
get_instr_fields(s1, s2, s3, m, t);
if (this->status == OK) {
curr_instr->set_s1(s1);
curr_instr->set_s2(s2);
curr_instr->set_s3(s3);
curr_instr->set_mnemonic(m);
curr_instr->set_type(t);
}
}
}
void ID::get_instr_fields(
signed int &s1, signed int &s2, signed int &s3, Mnemonic &m, Type &t)
{
unsigned int type;
this->split_instr(s1, type, m);
switch (type) {
case 0b00:
t = R;
this->decode_R_type(s1, s2, s3, m);
break;
case 0b01:
t = I;
this->decode_I_type(s1, s2, s3, m);
break;
case 0b10:
t = J;
this->decode_J_type(s1, s2, s3);
break;
case 0b11:
t = INV;
this->status = OK;
}
}
void ID::decode_R_type(
signed int &s1, signed int &s2, signed int &s3, Mnemonic &m)
{
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->status = (r1 == OK && r2 == OK) ? OK : STALLED;
switch (m) {
case CMP:
case CEV:
break;
default:
if (this->status == OK)
this->write_guard(s3);
}
}
void ID::decode_I_type(
signed int &s1, signed int &s2, signed int &s3, Mnemonic &m)
{
unsigned int s0b, s1b, s2b;
Response r1, r2;
s0b = REG_SIZE;
s1b = s0b + REG_SIZE;
s2b = WORD_SPEC - LINE_SPEC - OPCODE_SIZE;
s3 = GET_BITS_SIGN_EXTEND(s1, s1b, s2b);
switch (m) {
case STORE:
case STOREV:
s2 = GET_MID_BITS(s1, s0b, s1b);
s1 = GET_LS_BITS(s1, s0b);
// both operands are read values
r1 = this->read_guard(s1);
r2 = this->read_guard(s2);
this->status = (r1 == OK && r2 == OK) ? OK : STALLED;
return;
case LOAD:
case LOADV:
s2 = GET_LS_BITS(s1, s0b);
s1 = GET_MID_BITS(s1, s0b, s1b);
break;
default:
s2 = GET_MID_BITS(s1, s0b, s1b);
s1 = GET_LS_BITS(s1, s0b);
}
r1 = this->read_guard(s1);
if (r1 == OK)
this->write_guard(s2);
this->status = r1;
}
void ID::decode_J_type(signed int &s1, signed int &s2, signed int &s3)
{
unsigned int s0b, s1b;
s0b = REG_SIZE;
s1b = WORD_SPEC - LINE_SPEC - OPCODE_SIZE;
s3 = 0;
s2 = GET_BITS_SIGN_EXTEND(s1, s0b, s1b);
s1 = GET_LS_BITS(s1, s0b);
this->status = this->read_guard(*&s1);
}
std::vector<int> ID::stage_info()
{
std::vector<int> info;
if (this->curr_instr) {
info.push_back(this->curr_instr->get_pc());
info.push_back(this->curr_instr->get_instr_bits());
}
return info;
}
|
