blob: 53d31fec0eeb09138de3b2b4d630d53f9db5804e (
plain)
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
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
|
#include "booksim.hpp"
#include <iostream>
#include "selalloc.hpp"
#include "random_utils.hpp"
//#define DEBUG_SELALLOC
SelAlloc::SelAlloc( const Configuration &config,
Module *parent, const string& name,
int inputs, int outputs ) :
SparseAllocator( config, parent, name, inputs, outputs )
{
_iter = config.GetInt( "alloc_iters" );
_grants = new int [_outputs];
_gptrs = new int [_outputs];
_aptrs = new int [_inputs];
for ( int i = 0; i < _inputs; ++i ) {
_aptrs[i] = 0;
}
for ( int j = 0; j < _outputs; ++j ) {
_gptrs[j] = 0;
}
}
SelAlloc::~SelAlloc( )
{
delete [] _grants;
delete [] _aptrs;
delete [] _gptrs;
}
void SelAlloc::Allocate( )
{
int input;
int output;
int input_offset;
int output_offset;
list<sRequest>::iterator p;
list<int>::iterator outer_iter;
bool wrapped;
int max_index;
int max_pri;
_ClearMatching( );
for ( int i = 0; i < _outputs; ++i ) {
_grants[i] = -1;
}
for ( int iter = 0; iter < _iter; ++iter ) {
// Grant phase
for ( outer_iter = _out_occ.begin( );
outer_iter != _out_occ.end( ); ++outer_iter ) {
output = *outer_iter;
// Skip loop if there are no requests
// or the output is already matched or
// the output is masked
if ( ( _out_req[output].empty( ) ) ||
( _outmatch[output] != -1 ) ||
( _outmask[output] != 0 ) ) {
continue;
}
// A round-robin arbiter between input requests
input_offset = _gptrs[output];
p = _out_req[output].begin( );
while ( ( p != _out_req[output].end( ) ) &&
( p->port < input_offset ) ) {
p++;
}
max_index = -1;
max_pri = 0;
wrapped = false;
while ( (!wrapped) || ( p->port < input_offset ) ) {
if ( p == _out_req[output].end( ) ) {
if ( wrapped ) {
break;
}
// p is valid here because empty lists
// are skipped (above)
p = _out_req[output].begin( );
wrapped = true;
}
input = p->port;
// we know the output is free (above) and
// if the input is free, check if request is the
// highest priority so far
if ( ( _inmatch[input] == -1 ) &&
( ( p->out_pri > max_pri ) || ( max_index == -1 ) ) ) {
max_pri = p->out_pri;
max_index = input;
}
p++;
}
if ( max_index != -1 ) { // grant
_grants[output] = max_index;
}
}
#ifdef DEBUG_SELALLOC
cout << "grants: ";
for ( int i = 0; i < _outputs; ++i ) {
cout << _grants[i] << " ";
}
cout << endl;
cout << "aptrs: ";
for ( int i = 0; i < _inputs; ++i ) {
cout << _aptrs[i] << " ";
}
cout << endl;
#endif
// Accept phase
for ( outer_iter = _in_occ.begin( );
outer_iter != _in_occ.end( ); ++outer_iter ) {
input = *outer_iter;
if ( _in_req[input].empty( ) ) {
continue;
}
// A round-robin arbiter between output grants
output_offset = _aptrs[input];
p = _in_req[input].begin( );
while ( ( p != _in_req[input].end( ) ) &&
( p->port < output_offset ) ) {
p++;
}
max_index = -1;
max_pri = 0;
wrapped = false;
while ( (!wrapped) || ( p->port < output_offset ) ) {
if ( p == _in_req[input].end( ) ) {
if ( wrapped ) {
break;
}
// p is valid here because empty lists
// are skipped (above)
p = _in_req[input].begin( );
wrapped = true;
}
output = p->port;
// we know the output is free (above) and
// if the input is free, check if the highest
// priroity
if ( ( _grants[output] == input ) &&
( !_out_req[output].empty( ) ) &&
( ( p->in_pri > max_pri ) || ( max_index == -1 ) ) ) {
max_pri = p->in_pri;
max_index = output;
}
p++;
}
if ( max_index != -1 ) {
// Accept
output = max_index;
_inmatch[input] = output;
_outmatch[output] = input;
// Only update pointers if accepted during the 1st iteration
if ( iter == 0 ) {
_gptrs[output] = ( input + 1 ) % _inputs;
_aptrs[input] = ( output + 1 ) % _outputs;
}
}
}
}
#ifdef DEBUG_SELALLOC
cout << "input match: ";
for ( int i = 0; i < _inputs; ++i ) {
cout << _inmatch[i] << " ";
}
cout << endl;
cout << "output match: ";
for ( int j = 0; j < _outputs; ++j ) {
cout << _outmatch[j] << " ";
}
cout << endl;
#endif
}
|
