1// Copyright 2014, ARM Limited
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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 BUF_SIZE (4096)
30#define __ masm->
31
32void GenerateCheckBounds(MacroAssembler* masm) {
33  // uint64_t check_bounds(uint64_t value, uint64_t low, uint64_t high)
34  // Argument locations:
35  //   value -> x0
36  //   low   -> x1
37  //   high  -> x2
38
39  // First we compare 'value' with the 'low' bound. If x1 <= x0 the N flag will
40  // be cleared. This configuration can be checked with the 'pl' condition.
41  __ Cmp(x0, x1);
42
43  // Now we will compare 'value' and 'high' (x0 and x2) but only if the 'pl'
44  // condition is verified. If the condition is not verified, we will clear
45  // all the flags except the carry one (C flag).
46  __ Ccmp(x0, x2, CFlag, pl);
47
48  // We set x0 to 1 only if the 'ls' condition is satisfied.
49  // 'ls' performs the following test: !(C==1 && Z==0). If the previous
50  // comparison has been skipped we have C==1 and Z==0, so the 'ls' test
51  // will fail and x0 will be set to 0.
52  // Otherwise if the previous comparison occurred, x0 will be set to 1
53  // only if x0 is less than or equal to x2.
54  __ Cset(x0, ls);
55
56  __ Ret();
57}
58
59
60#ifndef TEST_EXAMPLES
61#ifdef VIXL_INCLUDE_SIMULATOR
62void run_function(Simulator *simulator, Instruction * function,
63                  uint64_t value, uint64_t low, uint64_t high) {
64  simulator->set_xreg(0, value);
65  simulator->set_xreg(1, low);
66  simulator->set_xreg(2, high);
67
68  simulator->RunFrom(function);
69  printf("%ld %s between %ld and %ld\n", value,
70         simulator->xreg(0) ? "is" : "is not",
71         low, high);
72
73  simulator->ResetState();
74}
75
76int main(void) {
77  // Create and initialize the assembler and the simulator.
78  byte assm_buf[BUF_SIZE];
79  MacroAssembler masm(assm_buf, BUF_SIZE);
80  Decoder decoder;
81  Simulator simulator(&decoder);
82
83  // Generate the code for the example function.
84  Label check_bounds;
85  masm.Bind(&check_bounds);
86  GenerateCheckBounds(&masm);
87  masm.FinalizeCode();
88
89  // Run the example function.
90  Instruction * function = masm.GetLabelAddress<Instruction*>(&check_bounds);
91  run_function(&simulator, function, 546, 50, 1000);
92  run_function(&simulator, function, 62, 100, 200);
93  run_function(&simulator, function, 200, 100, 200);
94
95  return 0;
96}
97#else
98// Without the simulator there is nothing to test.
99int main(void) { return 0; }
100#endif  // VIXL_INCLUDE_SIMULATOR
101#endif  // TEST_EXAMPLES
102