1/*
2 * Copyright (c) 2012 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 __ARCH_ARM_DECODER_HH__
32#define __ARCH_ARM_DECODER_HH__
33
34#include <cassert>
35
36#include "arch/arm/miscregs.hh"
37#include "arch/arm/types.hh"
38#include "arch/generic/decode_cache.hh"
39#include "base/types.hh"
40#include "cpu/static_inst.hh"
41
42namespace ArmISA
43{
44
45class Decoder
46{
47 protected:
48 //The extended machine instruction being generated
49 ExtMachInst emi;
50 MachInst data;
51 bool bigThumb;
52 bool instDone;
53 bool outOfBytes;
54 int offset;
55 bool foundIt;
56 ITSTATE itBits;
57
58 int fpscrLen;
59 int fpscrStride;
60
61 public:
62 void reset()
63 {
64 bigThumb = false;
65 offset = 0;
66 emi = 0;
67 instDone = false;
68 outOfBytes = true;
69 foundIt = false;
70 }
71
72 Decoder() : data(0), fpscrLen(0), fpscrStride(0)
73 {
74 reset();
75 }
76
77 void process();
78
79 //Use this to give data to the decoder. This should be used
80 //when there is control flow.
81 void moreBytes(const PCState &pc, Addr fetchPC, MachInst inst);
82
83 //Use this to give data to the decoder. This should be used
84 //when instructions are executed in order.
85 void moreBytes(MachInst machInst)
86 {
87 moreBytes(0, 0, machInst);
88 }
89
90 inline void consumeBytes(int numBytes)
91 {
92 offset += numBytes;
93 assert(offset <= sizeof(MachInst));
94 if (offset == sizeof(MachInst))
95 outOfBytes = true;
96 }
97
98 bool needMoreBytes() const
99 {
100 return outOfBytes;
101 }
102
103 bool instReady() const
104 {
105 return instDone;
106 }
107
108 int getInstSize() const
109 {
110 return (!emi.thumb || emi.bigThumb) ? 4 : 2;
111 }
112
113 void setContext(FPSCR fpscr)
114 {
115 fpscrLen = fpscr.len;
116 fpscrStride = fpscr.stride;
117 }
118
| 1/*
2 * Copyright (c) 2012 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 __ARCH_ARM_DECODER_HH__
32#define __ARCH_ARM_DECODER_HH__
33
34#include <cassert>
35
36#include "arch/arm/miscregs.hh"
37#include "arch/arm/types.hh"
38#include "arch/generic/decode_cache.hh"
39#include "base/types.hh"
40#include "cpu/static_inst.hh"
41
42namespace ArmISA
43{
44
45class Decoder
46{
47 protected:
48 //The extended machine instruction being generated
49 ExtMachInst emi;
50 MachInst data;
51 bool bigThumb;
52 bool instDone;
53 bool outOfBytes;
54 int offset;
55 bool foundIt;
56 ITSTATE itBits;
57
58 int fpscrLen;
59 int fpscrStride;
60
61 public:
62 void reset()
63 {
64 bigThumb = false;
65 offset = 0;
66 emi = 0;
67 instDone = false;
68 outOfBytes = true;
69 foundIt = false;
70 }
71
72 Decoder() : data(0), fpscrLen(0), fpscrStride(0)
73 {
74 reset();
75 }
76
77 void process();
78
79 //Use this to give data to the decoder. This should be used
80 //when there is control flow.
81 void moreBytes(const PCState &pc, Addr fetchPC, MachInst inst);
82
83 //Use this to give data to the decoder. This should be used
84 //when instructions are executed in order.
85 void moreBytes(MachInst machInst)
86 {
87 moreBytes(0, 0, machInst);
88 }
89
90 inline void consumeBytes(int numBytes)
91 {
92 offset += numBytes;
93 assert(offset <= sizeof(MachInst));
94 if (offset == sizeof(MachInst))
95 outOfBytes = true;
96 }
97
98 bool needMoreBytes() const
99 {
100 return outOfBytes;
101 }
102
103 bool instReady() const
104 {
105 return instDone;
106 }
107
108 int getInstSize() const
109 {
110 return (!emi.thumb || emi.bigThumb) ? 4 : 2;
111 }
112
113 void setContext(FPSCR fpscr)
114 {
115 fpscrLen = fpscr.len;
116 fpscrStride = fpscr.stride;
117 }
118
|
119 protected:
120 /// A cache of decoded instruction objects.
121 static GenericISA::BasicDecodeCache defaultCache;
122
123 public:
124 StaticInstPtr decodeInst(ExtMachInst mach_inst);
125
126 /// Decode a machine instruction.
127 /// @param mach_inst The binary instruction to decode.
128 /// @retval A pointer to the corresponding StaticInst object.
129 StaticInstPtr
130 decode(ExtMachInst mach_inst, Addr addr)
131 {
132 return defaultCache.decode(this, mach_inst, addr);
133 }
134
135 StaticInstPtr
136 decode(ArmISA::PCState &nextPC)
137 {
138 if (!instDone)
139 return NULL;
140
141 assert(instDone);
142 ExtMachInst thisEmi = emi;
143 nextPC.npc(nextPC.pc() + getInstSize());
144 if (foundIt)
145 nextPC.nextItstate(itBits);
146 thisEmi.itstate = nextPC.itstate();
147 nextPC.size(getInstSize());
148 emi = 0;
149 instDone = false;
150 foundIt = false;
151 return decode(thisEmi, nextPC.instAddr());
152 }
153};
154
155} // namespace ArmISA
156
157#endif // __ARCH_ARM_DECODER_HH__
| 121 protected:
122 /// A cache of decoded instruction objects.
123 static GenericISA::BasicDecodeCache defaultCache;
124
125 public:
126 StaticInstPtr decodeInst(ExtMachInst mach_inst);
127
128 /// Decode a machine instruction.
129 /// @param mach_inst The binary instruction to decode.
130 /// @retval A pointer to the corresponding StaticInst object.
131 StaticInstPtr
132 decode(ExtMachInst mach_inst, Addr addr)
133 {
134 return defaultCache.decode(this, mach_inst, addr);
135 }
136
137 StaticInstPtr
138 decode(ArmISA::PCState &nextPC)
139 {
140 if (!instDone)
141 return NULL;
142
143 assert(instDone);
144 ExtMachInst thisEmi = emi;
145 nextPC.npc(nextPC.pc() + getInstSize());
146 if (foundIt)
147 nextPC.nextItstate(itBits);
148 thisEmi.itstate = nextPC.itstate();
149 nextPC.size(getInstSize());
150 emi = 0;
151 instDone = false;
152 foundIt = false;
153 return decode(thisEmi, nextPC.instAddr());
154 }
155};
156
157} // namespace ArmISA
158
159#endif // __ARCH_ARM_DECODER_HH__
|