1/*
2 * Copyright (c) 2011 Google
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Gabe Black
29 */
30
31#ifndef __CPU_DECODE_CACHE_HH__
32#define __CPU_DECODE_CACHE_HH__
33
34#include <unordered_map>
35
36#include "arch/isa_traits.hh"
37#include "arch/types.hh"
38#include "config/the_isa.hh"
39#include "cpu/static_inst_fwd.hh"
40
41namespace TheISA
42{
43 class Decoder;
44}
45
46namespace DecodeCache
47{
48
49/// Hash for decoded instructions.
| 1/*
2 * Copyright (c) 2011 Google
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Gabe Black
29 */
30
31#ifndef __CPU_DECODE_CACHE_HH__
32#define __CPU_DECODE_CACHE_HH__
33
34#include <unordered_map>
35
36#include "arch/isa_traits.hh"
37#include "arch/types.hh"
38#include "config/the_isa.hh"
39#include "cpu/static_inst_fwd.hh"
40
41namespace TheISA
42{
43 class Decoder;
44}
45
46namespace DecodeCache
47{
48
49/// Hash for decoded instructions.
|
51
52/// A sparse map from an Addr to a Value, stored in page chunks.
53template<class Value>
54class AddrMap
55{
56 protected:
57 // A pages worth of cache entries.
58 struct CachePage {
59 Value items[TheISA::PageBytes];
60 };
61 // A map of cache pages which allows a sparse mapping.
62 typedef typename std::unordered_map<Addr, CachePage *> PageMap;
63 typedef typename PageMap::iterator PageIt;
64 // Mini cache of recent lookups.
65 PageIt recent[2];
66 PageMap pageMap;
67
68 /// Update the mini cache of recent lookups.
69 /// @param recentest The most recent result;
70 void
71 update(PageIt recentest)
72 {
73 recent[1] = recent[0];
74 recent[0] = recentest;
75 }
76
77 /// Attempt to find the CacheePage which goes with a particular
78 /// address. First check the small cache of recent results, then
79 /// actually look in the hash map.
80 /// @param addr The address to look up.
81 CachePage *
82 getPage(Addr addr)
83 {
84 Addr page_addr = addr & ~(TheISA::PageBytes - 1);
85
86 // Check against recent lookups.
87 if (recent[0] != pageMap.end()) {
88 if (recent[0]->first == page_addr)
89 return recent[0]->second;
90 if (recent[1] != pageMap.end() &&
91 recent[1]->first == page_addr) {
92 update(recent[1]);
93 // recent[1] has just become recent[0].
94 return recent[0]->second;
95 }
96 }
97
98 // Actually look in the has_map.
99 PageIt it = pageMap.find(page_addr);
100 if (it != pageMap.end()) {
101 update(it);
102 return it->second;
103 }
104
105 // Didn't find an existing page, so add a new one.
106 CachePage *newPage = new CachePage;
107 page_addr = page_addr & ~(TheISA::PageBytes - 1);
108 typename PageMap::value_type to_insert(page_addr, newPage);
109 update(pageMap.insert(to_insert).first);
110 return newPage;
111 }
112
113 public:
114 /// Constructor
115 AddrMap()
116 {
117 recent[0] = recent[1] = pageMap.end();
118 }
119
120 Value &
121 lookup(Addr addr)
122 {
123 CachePage *page = getPage(addr);
124 return page->items[addr & (TheISA::PageBytes - 1)];
125 }
126};
127
128} // namespace DecodeCache
129
130#endif // __CPU_DECODE_CACHE_HH__
| 52
53/// A sparse map from an Addr to a Value, stored in page chunks.
54template<class Value>
55class AddrMap
56{
57 protected:
58 // A pages worth of cache entries.
59 struct CachePage {
60 Value items[TheISA::PageBytes];
61 };
62 // A map of cache pages which allows a sparse mapping.
63 typedef typename std::unordered_map<Addr, CachePage *> PageMap;
64 typedef typename PageMap::iterator PageIt;
65 // Mini cache of recent lookups.
66 PageIt recent[2];
67 PageMap pageMap;
68
69 /// Update the mini cache of recent lookups.
70 /// @param recentest The most recent result;
71 void
72 update(PageIt recentest)
73 {
74 recent[1] = recent[0];
75 recent[0] = recentest;
76 }
77
78 /// Attempt to find the CacheePage which goes with a particular
79 /// address. First check the small cache of recent results, then
80 /// actually look in the hash map.
81 /// @param addr The address to look up.
82 CachePage *
83 getPage(Addr addr)
84 {
85 Addr page_addr = addr & ~(TheISA::PageBytes - 1);
86
87 // Check against recent lookups.
88 if (recent[0] != pageMap.end()) {
89 if (recent[0]->first == page_addr)
90 return recent[0]->second;
91 if (recent[1] != pageMap.end() &&
92 recent[1]->first == page_addr) {
93 update(recent[1]);
94 // recent[1] has just become recent[0].
95 return recent[0]->second;
96 }
97 }
98
99 // Actually look in the has_map.
100 PageIt it = pageMap.find(page_addr);
101 if (it != pageMap.end()) {
102 update(it);
103 return it->second;
104 }
105
106 // Didn't find an existing page, so add a new one.
107 CachePage *newPage = new CachePage;
108 page_addr = page_addr & ~(TheISA::PageBytes - 1);
109 typename PageMap::value_type to_insert(page_addr, newPage);
110 update(pageMap.insert(to_insert).first);
111 return newPage;
112 }
113
114 public:
115 /// Constructor
116 AddrMap()
117 {
118 recent[0] = recent[1] = pageMap.end();
119 }
120
121 Value &
122 lookup(Addr addr)
123 {
124 CachePage *page = getPage(addr);
125 return page->items[addr & (TheISA::PageBytes - 1)];
126 }
127};
128
129} // namespace DecodeCache
130
131#endif // __CPU_DECODE_CACHE_HH__
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