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
32using namespace vixl;
33
34static 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.
40int 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