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
|
#include "icsim.h"
#include <stdexcept>
#include <iostream>
#include <iomanip>
icsim_t::icsim_t(size_t _sets, size_t _ways, size_t _linesz, const char* _name)
: sets(_sets), ways(_ways), linesz(_linesz), idx_mask(_sets-1), name(_name)
{
if(sets == 0 || (sets & (sets-1)))
throw std::logic_error("sets not a power of 2");
if(linesz == 0 || (linesz & (linesz-1)))
throw std::logic_error("linesz not a power of 2");
idx_shift = 0;
while(_linesz >>= 1)
idx_shift++;
tags = new uint64_t[sets*ways];
memset(tags, 0, sets*ways*sizeof(uint64_t));
read_accesses = 0;
read_misses = 0;
bytes_read = 0;
write_accesses = 0;
write_misses = 0;
bytes_written = 0;
writebacks = 0;
}
icsim_t::icsim_t(const icsim_t& rhs)
: sets(rhs.sets), ways(rhs.ways), linesz(rhs.linesz),
idx_shift(rhs.idx_shift), idx_mask(rhs.idx_mask), name(rhs.name)
{
tags = new uint64_t[sets*ways];
memcpy(tags, rhs.tags, sets*ways*sizeof(uint64_t));
}
icsim_t::~icsim_t()
{
delete [] tags;
}
void icsim_t::print_stats()
{
if(read_accesses + write_accesses == 0)
return;
float mr = 100.0f*(read_misses+write_misses)/(read_accesses+write_accesses);
std::cout << std::setprecision(3) << std::fixed;
std::cout << name << " ";
std::cout << "Bytes Read: " << bytes_read << std::endl;
std::cout << name << " ";
std::cout << "Bytes Written: " << bytes_written << std::endl;
std::cout << name << " ";
std::cout << "Read Accesses: " << read_accesses << std::endl;
std::cout << name << " ";
std::cout << "Write Accesses: " << write_accesses << std::endl;
std::cout << name << " ";
std::cout << "Read Misses: " << read_misses << std::endl;
std::cout << name << " ";
std::cout << "Write Misses: " << write_misses << std::endl;
std::cout << name << " ";
std::cout << "Writebacks: " << writebacks << std::endl;
std::cout << name << " ";
std::cout << "Miss Rate: " << mr << '%' << std::endl;
float cr = read_accesses == 0 ? 0.0f : 100.0f*bytes_read/(4*read_accesses);
if(name == "I$")
{
std::cout << name << " ";
std::cout << "RVC compression ratio: " << cr << '%' << std::endl;
}
}
void icsim_t::tick(uint64_t pc, int insnlen, bool store)
{
store ? write_accesses++ : read_accesses++;
(store ? bytes_written : bytes_read) += insnlen;
size_t idx = (pc >> idx_shift) & idx_mask;
size_t tag = (pc >> idx_shift) | VALID;
for(size_t i = 0; i < ways; i++)
{
if(tag == (tags[idx + i*sets] & ~DIRTY)) // hit
{
if(store)
tags[idx + i*sets] |= DIRTY;
return;
}
}
store ? write_misses++ : read_misses++;
size_t way = lfsr.next() % ways;
if((tags[idx + way*sets] & (VALID | DIRTY)) == (VALID | DIRTY))
writebacks++;
tags[idx + way*sets] = tag;
}
|
