1 // Copyright 2014, VIXL authors
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions are met:
6 //
7 // * Redistributions of source code must retain the above copyright notice,
8 // this list of conditions and the following disclaimer.
9 // * Redistributions in binary form must reproduce the above copyright notice,
10 // this list of conditions and the following disclaimer in the documentation
11 // and/or other materials provided with the distribution.
12 // * Neither the name of ARM Limited nor the names of its contributors may be
13 // used to endorse or promote products derived from this software without
14 // specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
17 // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
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21 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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25 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26
27 #include "non-const-visitor.h"
28 #include "examples.h"
29
30 #define __ masm->
31
32
GenerateNonConstVisitorTestCode(MacroAssembler * masm)33 void GenerateNonConstVisitorTestCode(MacroAssembler* masm) {
34 // int64_t foo(int64_t a, int64_t b)
35 // Argument locations:
36 // a -> x0
37 // b -> x1
38 __ Sub(x0, x0, x1);
39 // The return value is in x0.
40 __ Ret();
41 }
42
43
RunNonConstVisitorTestGeneratedCode(const Instruction * start_instr)44 int64_t RunNonConstVisitorTestGeneratedCode(const Instruction* start_instr) {
45 #ifdef VIXL_INCLUDE_SIMULATOR_AARCH64
46 Decoder simulator_decoder;
47 Simulator simulator(&simulator_decoder);
48
49 int64_t a = 5;
50 int64_t b = 2;
51 simulator.WriteXRegister(0, a);
52 simulator.WriteXRegister(1, b);
53 simulator.RunFrom(start_instr);
54 int64_t res = simulator.ReadXRegister(0);
55 printf("foo(%" PRId64 ", %" PRId64 ") = %" PRId64 "\n", a, b, res);
56
57 return res;
58 #else
59 // Without the simulator there is nothing to test.
60 USE(start_instr);
61 return 0;
62 #endif
63 }
64
65
66 #ifndef TEST_EXAMPLES
67 #ifdef VIXL_INCLUDE_SIMULATOR_AARCH64
main(void)68 int main(void) {
69 MacroAssembler masm;
70
71 // Generate the code.
72 Label code_start, code_end;
73 masm.Bind(&code_start);
74 GenerateNonConstVisitorTestCode(&masm);
75 masm.Bind(&code_end);
76 masm.FinalizeCode();
77 Instruction* instr_start = masm.GetLabelAddress<Instruction*>(&code_start);
78 Instruction* instr_end = masm.GetLabelAddress<Instruction*>(&code_end);
79
80 // Run the code a first time.
81 RunNonConstVisitorTestGeneratedCode(instr_start);
82
83 // Instantiate a decoder, disassembler, and our custom modifying visitor.
84 Decoder decoder;
85 PrintDisassembler disasm(stdout);
86 SwitchAddSubRegisterSources modifying_visitor;
87
88 // Register visitors in such a way that when visiting instructions, the
89 // decoder will first disassemble the original instruction, modify it, and
90 // then disassemble the modified instruction.
91 decoder.AppendVisitor(&disasm);
92 decoder.AppendVisitor(&modifying_visitor);
93 decoder.AppendVisitor(&disasm);
94
95 // Iterate through the instructions.
96 Instruction* instr;
97 for (instr = instr_start; instr < instr_end; instr += kInstructionSize) {
98 printf("---\n");
99 decoder.Decode(instr);
100 }
101
102 // Run the modified code and observe the different output from before.
103 RunNonConstVisitorTestGeneratedCode(instr_start);
104
105 return 0;
106 }
107 #else
108 // Without the simulator there is nothing to test.
main(void)109 int main(void) { return 0; }
110 #endif // VIXL_INCLUDE_SIMULATOR_AARCH64
111 #endif // TEST_EXAMPLES
112
113
114 // This is only used by the testing code.
ModifyNonConstVisitorTestGeneratedCode(Instruction * start,Instruction * end)115 void ModifyNonConstVisitorTestGeneratedCode(Instruction* start,
116 Instruction* end) {
117 Decoder decoder;
118 SwitchAddSubRegisterSources modifying_visitor;
119 decoder.AppendVisitor(&modifying_visitor);
120
121 Instruction* instr;
122 for (instr = start; instr < end; instr += kInstructionSize) {
123 printf("---\n");
124 decoder.Decode(instr);
125 }
126 }
127