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
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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 "examples.h"
28
29 #define ARRAY_SIZE(Array) (sizeof(Array) / sizeof((Array)[0]))
30 #define __ masm->
31
GenerateSumArray(MacroAssembler * masm)32 void GenerateSumArray(MacroAssembler* masm) {
33 // uint32_t sum_array(uint8_t* array, uint32_t size)
34 // Argument locations:
35 // array (pointer) -> x0
36 // size -> x1
37
38 Label loop, end;
39
40 __ Mov(x2, x0);
41 __ Mov(w0, 0);
42
43 // There's nothing to do if the array is empty.
44 __ Cbz(w1, &end);
45
46 // Go through the array and sum the elements.
47 __ Bind(&loop);
48
49 __ Ldrb(w3, MemOperand(x2, 1, PostIndex)); // w3 = *(x2++)
50 __ Add(w0, w0, w3);
51
52 __ Sub(w1, w1, 1);
53 __ Cbnz(w1, &loop);
54
55 __ Bind(&end);
56 __ Ret();
57 }
58
59
60 #ifndef TEST_EXAMPLES
61 #ifdef VIXL_INCLUDE_SIMULATOR_AARCH64
main(void)62 int main(void) {
63 MacroAssembler masm;
64 Decoder decoder;
65 Simulator simulator(&decoder);
66
67 // Generate the code for the example function.
68 Label sum_array;
69 masm.Bind(&sum_array);
70 GenerateSumArray(&masm);
71 masm.FinalizeCode();
72
73 // Run the example function.
74 uint8_t data[] = {2, 45, 63, 7, 245, 38};
75 uintptr_t data_addr = reinterpret_cast<uintptr_t>(data);
76 simulator.WriteXRegister(0, data_addr);
77 simulator.WriteXRegister(1, ARRAY_SIZE(data));
78 simulator.RunFrom(masm.GetLabelAddress<Instruction*>(&sum_array));
79
80 unsigned int i;
81 for (i = 0; i < ARRAY_SIZE(data) - 1; ++i) {
82 printf("%d + ", data[i]);
83 }
84 printf("%d = %d\n", data[i], simulator.ReadWRegister(0));
85
86 return 0;
87 }
88 #else
89 // Without the simulator there is nothing to test.
main(void)90 int main(void) { return 0; }
91 #endif // VIXL_INCLUDE_SIMULATOR_AARCH64
92 #endif // TEST_EXAMPLES
93