1 // Copyright 2014, ARM Limited
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5 // modification, are permitted provided that the following conditions are met:
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26
27 #include "examples.h"
28 #include "non-const-visitor.h"
29
30 #define BUF_SIZE (4096)
31 #define __ masm->
32
33
GenerateNonConstVisitorTestCode(MacroAssembler * masm)34 void GenerateNonConstVisitorTestCode(MacroAssembler* masm) {
35 // int64_t foo(int64_t a, int64_t b)
36 // Argument locations:
37 // a -> x0
38 // b -> x1
39 __ Sub(x0, x0, x1);
40 // The return value is in x0.
41 __ Ret();
42 }
43
44
RunNonConstVisitorTestGeneratedCode(const Instruction * start_instr)45 int64_t RunNonConstVisitorTestGeneratedCode(const Instruction* start_instr) {
46 #ifdef USE_SIMULATOR
47 Decoder simulator_decoder;
48 Simulator simulator(&simulator_decoder);
49
50 int64_t a = 5;
51 int64_t b = 2;
52 simulator.set_xreg(0, a);
53 simulator.set_xreg(1, b);
54 simulator.RunFrom(start_instr);
55 int64_t res = simulator.xreg(0);
56 printf("foo(%" PRId64", %" PRId64") = %" PRId64"\n", a, b, res);
57
58 return res;
59 #else
60 // Without the simulator there is nothing to test.
61 USE(start_instr);
62 return 0;
63 #endif
64 }
65
66
67 #ifndef TEST_EXAMPLES
68 #ifdef USE_SIMULATOR
main(void)69 int main(void) {
70 // Create and initialize the assembler.
71 byte assm_buf[BUF_SIZE];
72 MacroAssembler masm(assm_buf, BUF_SIZE);
73
74 // Generate the code.
75 Label code_start, code_end;
76 masm.Bind(&code_start);
77 GenerateNonConstVisitorTestCode(&masm);
78 masm.Bind(&code_end);
79 masm.FinalizeCode();
80 Instruction* instr_start = masm.GetLabelAddress<Instruction*>(&code_start);
81 Instruction* instr_end = masm.GetLabelAddress<Instruction*>(&code_end);
82
83 // Run the code a first time.
84 RunNonConstVisitorTestGeneratedCode(instr_start);
85
86 // Instantiate a decoder, disassembler, and our custom modifying visitor.
87 Decoder decoder;
88 PrintDisassembler disasm(stdout);
89 SwitchAddSubRegisterSources modifying_visitor;
90
91 // Register visitors in such a way that when visiting instructions, the
92 // decoder will first disassemble the original instruction, modify it, and
93 // then disassemble the modified instruction.
94 decoder.AppendVisitor(&disasm);
95 decoder.AppendVisitor(&modifying_visitor);
96 decoder.AppendVisitor(&disasm);
97
98 // Iterate through the instructions.
99 Instruction* instr;
100 for (instr = instr_start; instr < instr_end; instr += kInstructionSize) {
101 printf("---\n");
102 decoder.Decode(instr);
103 }
104
105 // Run the modified code and observe the different output from before.
106 RunNonConstVisitorTestGeneratedCode(instr_start);
107
108 return 0;
109 }
110 #else
111 // Without the simulator there is nothing to test.
main(void)112 int main(void) { return 0; }
113 #endif // USE_SIMULATOR
114 #endif // TEST_EXAMPLES
115
116
117 // This is only used by the testing code.
ModifyNonConstVisitorTestGeneratedCode(Instruction * start,Instruction * end)118 void ModifyNonConstVisitorTestGeneratedCode(Instruction* start,
119 Instruction* end) {
120 Decoder decoder;
121 SwitchAddSubRegisterSources modifying_visitor;
122 decoder.AppendVisitor(&modifying_visitor);
123
124 Instruction* instr;
125 for (instr = start; instr < end; instr += kInstructionSize) {
126 printf("---\n");
127 decoder.Decode(instr);
128 }
129 }
130