X86: Don't read in dest regs if all bits are replaced.
[gem5.git] / src / arch / x86 / isa / microops / seqop.isa
1 // Copyright (c) 2008 The Hewlett-Packard Development Company
2 // All rights reserved.
3 //
4 // The license below extends only to copyright in the software and shall
5 // not be construed as granting a license to any other intellectual
6 // property including but not limited to intellectual property relating
7 // to a hardware implementation of the functionality of the software
8 // licensed hereunder. You may use the software subject to the license
9 // terms below provided that you ensure that this notice is replicated
10 // unmodified and in its entirety in all distributions of the software,
11 // modified or unmodified, in source code or in binary form.
12 //
13 // Redistribution and use in source and binary forms, with or without
14 // modification, are permitted provided that the following conditions are
15 // met: redistributions of source code must retain the above copyright
16 // notice, this list of conditions and the following disclaimer;
17 // redistributions in binary form must reproduce the above copyright
18 // notice, this list of conditions and the following disclaimer in the
19 // documentation and/or other materials provided with the distribution;
20 // neither the name of the copyright holders nor the names of its
21 // contributors may be used to endorse or promote products derived from
22 // this software without specific prior written permission.
23 //
24 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
27 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
28 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
29 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
30 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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33 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
34 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 //
36 // Authors: Gabe Black
37
38 output header {{
39 class SeqOpBase : public X86ISA::X86MicroopBase
40 {
41 protected:
42 uint16_t target;
43 uint8_t cc;
44
45 public:
46 SeqOpBase(ExtMachInst _machInst, const char * instMnem,
47 const char * mnemonic, uint64_t setFlags,
48 uint16_t _target, uint8_t _cc);
49
50 SeqOpBase(ExtMachInst _machInst, const char * instMnem,
51 const char * mnemonic,
52 uint16_t _target, uint8_t _cc);
53
54 std::string generateDisassembly(Addr pc,
55 const SymbolTable *symtab) const;
56 };
57 }};
58
59 def template SeqOpDeclare {{
60 class %(class_name)s : public %(base_class)s
61 {
62 public:
63 %(class_name)s(ExtMachInst _machInst, const char * instMnem,
64 uint64_t setFlags, uint16_t _target, uint8_t _cc);
65
66 %(BasicExecDeclare)s
67 };
68 }};
69
70 def template SeqOpExecute {{
71 Fault %(class_name)s::execute(%(CPU_exec_context)s *xc,
72 Trace::InstRecord *traceData) const
73 {
74 %(op_decl)s;
75 %(op_rd)s;
76 if (%(cond_test)s) {
77 %(code)s;
78 } else {
79 %(else_code)s;
80 }
81 %(op_wb)s;
82 return NoFault;
83 }
84 }};
85
86 output decoder {{
87 inline SeqOpBase::SeqOpBase(
88 ExtMachInst machInst, const char * mnemonic, const char * instMnem,
89 uint64_t setFlags, uint16_t _target, uint8_t _cc) :
90 X86MicroopBase(machInst, mnemonic, instMnem, setFlags, No_OpClass),
91 target(_target), cc(_cc)
92 {
93 }
94 }};
95
96 def template SeqOpConstructor {{
97 inline %(class_name)s::%(class_name)s(
98 ExtMachInst machInst, const char * instMnem,
99 uint64_t setFlags, uint16_t _target, uint8_t _cc) :
100 %(base_class)s(machInst, "%(mnemonic)s", instMnem,
101 setFlags, _target, _cc)
102 {
103 %(constructor)s;
104 %(cond_control_flag_init)s;
105 }
106 }};
107
108 output decoder {{
109 std::string SeqOpBase::generateDisassembly(Addr pc,
110 const SymbolTable *symtab) const
111 {
112 std::stringstream response;
113
114 printMnemonic(response, instMnem, mnemonic);
115 ccprintf(response, "%#x", target);
116
117 return response.str();
118 }
119 }};
120
121 let {{
122 class SeqOp(X86Microop):
123 def __init__(self, target, flags=None):
124 self.target = target
125 if flags:
126 if not isinstance(flags, (list, tuple)):
127 raise Exception, "flags must be a list or tuple of flags"
128 self.cond = " | ".join(flags)
129 self.className += "Flags"
130 else:
131 self.cond = "0"
132
133 def getAllocator(self, microFlags):
134 allocator = '''new %(class_name)s(machInst, macrocodeBlock,
135 %(flags)s, %(target)s, %(cc)s)''' % {
136 "class_name" : self.className,
137 "flags" : self.microFlagsText(microFlags),
138 "target" : self.target,
139 "cc" : self.cond}
140 return allocator
141
142 class Br(SeqOp):
143 className = "MicroBranch"
144
145 def getAllocator(self, microFlags):
146 if "IsLastMicroop" in microFlags:
147 microFlags.remove("IsLastMicroop")
148 if not "IsDelayedCommit" in microFlags:
149 microFlags.append("IsDelayedCommit")
150 return super(Br, self).getAllocator(microFlags)
151
152 class Eret(SeqOp):
153 target = "normalMicroPC(0)"
154 className = "Eret"
155
156 def __init__(self, flags=None):
157 if flags:
158 if not isinstance(flags, (list, tuple)):
159 raise Exception, "flags must be a list or tuple of flags"
160 self.cond = " | ".join(flags)
161 self.className += "Flags"
162 else:
163 self.cond = "0"
164
165 def getAllocator(self, microFlags):
166 if not "IsLastMicroop" in microFlags:
167 microFlags.append("IsLastMicroop")
168 if "IsDelayedCommit" in microFlags:
169 microFlags.remove("IsDelayedCommit")
170 return super(Eret, self).getAllocator(microFlags)
171
172 iop = InstObjParams("br", "MicroBranchFlags", "SeqOpBase",
173 {"code": "nuIP = target;",
174 "else_code": "nuIP = nuIP;",
175 "cond_test": "checkCondition(ccFlagBits, cc)",
176 "cond_control_flag_init": "flags[IsCondControl] = true"})
177 exec_output += SeqOpExecute.subst(iop)
178 header_output += SeqOpDeclare.subst(iop)
179 decoder_output += SeqOpConstructor.subst(iop)
180 iop = InstObjParams("br", "MicroBranch", "SeqOpBase",
181 {"code": "nuIP = target;",
182 "else_code": "nuIP = nuIP;",
183 "cond_test": "true",
184 "cond_control_flag_init": ""})
185 exec_output += SeqOpExecute.subst(iop)
186 header_output += SeqOpDeclare.subst(iop)
187 decoder_output += SeqOpConstructor.subst(iop)
188 microopClasses["br"] = Br
189
190 iop = InstObjParams("eret", "EretFlags", "SeqOpBase",
191 {"code": "", "else_code": "",
192 "cond_test": "checkCondition(ccFlagBits, cc)",
193 "cond_control_flag_init": ""})
194 exec_output += SeqOpExecute.subst(iop)
195 header_output += SeqOpDeclare.subst(iop)
196 decoder_output += SeqOpConstructor.subst(iop)
197 iop = InstObjParams("eret", "Eret", "SeqOpBase",
198 {"code": "", "else_code": "",
199 "cond_test": "true",
200 "cond_control_flag_init": ""})
201 exec_output += SeqOpExecute.subst(iop)
202 header_output += SeqOpDeclare.subst(iop)
203 decoder_output += SeqOpConstructor.subst(iop)
204 microopClasses["eret"] = Eret
205 }};