branch.isa (7294:fda2c00880db) branch.isa (7594:9c9b3648c732)
1// -*- mode:c++ -*-
2
3// Copyright (c) 2010 ARM Limited
4// All rights reserved
5//
6// The license below extends only to copyright in the software and shall
7// not be construed as granting a license to any other intellectual
8// property including but not limited to intellectual property relating

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41
42 header_output = ""
43 decoder_output = ""
44 exec_output = ""
45
46 # B, BL
47 for (mnem, link) in (("b", False), ("bl", True)):
48 bCode = '''
1// -*- mode:c++ -*-
2
3// Copyright (c) 2010 ARM Limited
4// All rights reserved
5//
6// The license below extends only to copyright in the software and shall
7// not be construed as granting a license to any other intellectual
8// property including but not limited to intellectual property relating

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41
42 header_output = ""
43 decoder_output = ""
44 exec_output = ""
45
46 # B, BL
47 for (mnem, link) in (("b", False), ("bl", True)):
48 bCode = '''
49 Addr PC = readPC(xc);
50 NPC = ((PC + imm) & mask(32)) | (PC & ~mask(32));
49 Addr curPc = readPC(xc);
50 NPC = ((curPc + imm) & mask(32)) | (curPc & ~mask(32));
51 '''
52 if (link):
53 bCode += '''
51 '''
52 if (link):
53 bCode += '''
54 Addr tBit = PC & (ULL(1) << PcTBitShift);
54 Addr tBit = curPc & (ULL(1) << PcTBitShift);
55 if (!tBit)
55 if (!tBit)
56 LR = PC - 4;
56 LR = curPc - 4;
57 else
57 else
58 LR = PC | 1;
58 LR = curPc | 1;
59 '''
60
61 bIop = InstObjParams(mnem, mnem.capitalize(), "BranchImmCond",
62 {"code": bCode,
63 "predicate_test": predicateTest})
64 header_output += BranchImmCondDeclare.subst(bIop)
65 decoder_output += BranchImmCondConstructor.subst(bIop)
66 exec_output += PredOpExecute.subst(bIop)
67
68 # BX, BLX
69 blxCode = '''
59 '''
60
61 bIop = InstObjParams(mnem, mnem.capitalize(), "BranchImmCond",
62 {"code": bCode,
63 "predicate_test": predicateTest})
64 header_output += BranchImmCondDeclare.subst(bIop)
65 decoder_output += BranchImmCondConstructor.subst(bIop)
66 exec_output += PredOpExecute.subst(bIop)
67
68 # BX, BLX
69 blxCode = '''
70 Addr PC = readPC(xc);
71 Addr tBit = PC & (ULL(1) << PcTBitShift);
70 Addr curPc = readPC(xc);
71 Addr tBit = curPc & (ULL(1) << PcTBitShift);
72 bool arm = !tBit;
73 arm = arm; // In case it's not used otherwise.
74 %(link)s
75 // Switch modes
76 %(branch)s
77 '''
78
79 blxList = (("blx", True, True),
80 ("blx", False, True),
81 ("bx", False, False))
82
83 for (mnem, imm, link) in blxList:
84 Name = mnem.capitalize()
85 if imm:
86 Name += "Imm"
87 # Since we're switching ISAs, the target ISA will be the opposite
88 # of the current ISA. !arm is whether the target is ARM.
72 bool arm = !tBit;
73 arm = arm; // In case it's not used otherwise.
74 %(link)s
75 // Switch modes
76 %(branch)s
77 '''
78
79 blxList = (("blx", True, True),
80 ("blx", False, True),
81 ("bx", False, False))
82
83 for (mnem, imm, link) in blxList:
84 Name = mnem.capitalize()
85 if imm:
86 Name += "Imm"
87 # Since we're switching ISAs, the target ISA will be the opposite
88 # of the current ISA. !arm is whether the target is ARM.
89 newPC = '(!arm ? (roundDown(PC, 4) + imm) : (PC + imm))'
89 newPC = '(!arm ? (roundDown(curPc, 4) + imm) : (curPc + imm))'
90 base = "BranchImm"
91 declare = BranchImmDeclare
92 constructor = BranchImmConstructor
93 else:
94 Name += "Reg"
95 newPC = 'Op1'
96 base = "BranchRegCond"
97 declare = BranchRegCondDeclare
98 constructor = BranchRegCondConstructor
99 if link and imm:
100 linkStr = '''
101 // The immediate version of the blx thumb instruction
102 // is 32 bits wide, but "next pc" doesn't reflect that
103 // so we don't want to substract 2 from it at this point
104 if (arm)
90 base = "BranchImm"
91 declare = BranchImmDeclare
92 constructor = BranchImmConstructor
93 else:
94 Name += "Reg"
95 newPC = 'Op1'
96 base = "BranchRegCond"
97 declare = BranchRegCondDeclare
98 constructor = BranchRegCondConstructor
99 if link and imm:
100 linkStr = '''
101 // The immediate version of the blx thumb instruction
102 // is 32 bits wide, but "next pc" doesn't reflect that
103 // so we don't want to substract 2 from it at this point
104 if (arm)
105 LR = PC - 4;
105 LR = curPc - 4;
106 else
106 else
107 LR = PC | 1;
107 LR = curPc | 1;
108 '''
109 elif link:
110 linkStr = '''
111 if (arm)
108 '''
109 elif link:
110 linkStr = '''
111 if (arm)
112 LR = PC - 4;
112 LR = curPc - 4;
113 else
113 else
114 LR = (PC - 2) | 1;
114 LR = (curPc - 2) | 1;
115 '''
116 else:
117 linkStr = ""
118
119 if imm and link: #blx with imm
120 branchStr = '''
115 '''
116 else:
117 linkStr = ""
118
119 if imm and link: #blx with imm
120 branchStr = '''
121 Addr tempPc = ((%(newPC)s) & mask(32)) | (PC & ~mask(32));
121 Addr tempPc = ((%(newPC)s) & mask(32)) | (curPc & ~mask(32));
122 FNPC = tempPc ^ (ULL(1) << PcTBitShift);
123 '''
124 else:
125 branchStr = "IWNPC = %(newPC)s;"
126 branchStr = branchStr % { "newPC" : newPC }
127
128 code = blxCode % {"link": linkStr,
129 "newPC": newPC,

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135 decoder_output += constructor.subst(blxIop)
136 exec_output += PredOpExecute.subst(blxIop)
137
138 #Ignore BXJ for now
139
140 #CBNZ, CBZ. These are always unconditional as far as predicates
141 for (mnem, test) in (("cbz", "=="), ("cbnz", "!=")):
142 code = '''
122 FNPC = tempPc ^ (ULL(1) << PcTBitShift);
123 '''
124 else:
125 branchStr = "IWNPC = %(newPC)s;"
126 branchStr = branchStr % { "newPC" : newPC }
127
128 code = blxCode % {"link": linkStr,
129 "newPC": newPC,

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135 decoder_output += constructor.subst(blxIop)
136 exec_output += PredOpExecute.subst(blxIop)
137
138 #Ignore BXJ for now
139
140 #CBNZ, CBZ. These are always unconditional as far as predicates
141 for (mnem, test) in (("cbz", "=="), ("cbnz", "!=")):
142 code = '''
143 Addr PC = readPC(xc);
144 NPC = ((PC + imm) & mask(32)) | (PC & ~mask(32));
143 Addr curPc = readPC(xc);
144 NPC = ((curPc + imm) & mask(32)) | (curPc & ~mask(32));
145 '''
146 predTest = "Op1 %(test)s 0" % {"test": test}
147 iop = InstObjParams(mnem, mnem.capitalize(), "BranchImmReg",
148 {"code": code, "predicate_test": predTest})
149 header_output += BranchImmRegDeclare.subst(iop)
150 decoder_output += BranchImmRegConstructor.subst(iop)
151 exec_output += PredOpExecute.subst(iop)
152

--- 30 unchanged lines hidden --- 		145 '''
146 predTest = "Op1 %(test)s 0" % {"test": test}
147 iop = InstObjParams(mnem, mnem.capitalize(), "BranchImmReg",
148 {"code": code, "predicate_test": predTest})
149 header_output += BranchImmRegDeclare.subst(iop)
150 decoder_output += BranchImmRegConstructor.subst(iop)
151 exec_output += PredOpExecute.subst(iop)
152

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