1 // Copyright 2015, ARM Limited
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
20 // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
23 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26
27 #include "vixl/globals.h"
28
29 #include "vixl/a64/macro-assembler-a64.h"
30 #include "vixl/a64/instructions-a64.h"
31
32 using namespace vixl;
33
34 static const int kDefaultIterationCount = 100000;
35
36 // This program focuses on emitting branch instructions targeting a label bound
37 // very closely. Here the MacroAssembler is used. This exercises label binding
38 // and patching mechanisms, as well as the veneer resolving mechanisms for
39 // branches not requiring veneers.
main(int argc,char * argv[])40 int main(int argc, char* argv[]) {
41 int iterations = 0;
42
43 switch (argc) {
44 case 1: iterations = kDefaultIterationCount; break;
45 case 2: iterations = atoi(argv[1]); break;
46 default:
47 printf("Usage: %s [#iterations]\n", argv[0]);
48 exit(1);
49 }
50
51 const int buffer_size = 256 * KBytes;
52 const int instructions_per_iteration = 4;
53 const int max_buffer_iterations =
54 buffer_size / (instructions_per_iteration * kInstructionSize);
55
56 MacroAssembler masm(buffer_size);
57
58 #define __ masm.
59
60 for (int i = 0; i < iterations;) {
61 masm.Reset();
62 for (int j = 0; (j < max_buffer_iterations) && (i < iterations); ++j, ++i) {
63 Label target;
64 __ B(&target);
65 __ B(eq, &target);
66 __ Cbz(x2, &target);
67 __ Tbz(x3, 2, &target);
68 __ Bind(&target);
69 }
70 }
71
72 masm.FinalizeCode();
73
74 return 0;
75 }
76