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
|
#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; }
Response ID::advance(InstrDTO &next_instr, Response p)
{
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;
}
n = (p != OK || this->status != OK) ? BLOCKED : OK;
// the power of consent
n = this->next->advance(next_instr, n);
}
void ID::get_instr_fields(
signed int &s1, signed int &s2, signed int &s3, Mnemonic &m)
{
unsigned int type;
this->split_instr(s1, type, m);
switch (type) {
case 0b00:
this->decode_R_type(s1, s2, s3);
break;
case 0b01:
this->decode_I_type(s1, s2, s3);
break;
case 0b10:
this->decode_J_type(s1, s2);
break;
}
}
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 = BLOCKED;
else {
r = OK;
v = this->dereference_register(v);
}
return r;
}
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);
}
|
