1 // Copyright 2013, 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 "examples.h" 28 29 #define BUF_SIZE (4096) 30 #define __ masm-> 31 32 void 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 void run_function(Simulator *simulator, Label *function, 62 uint64_t value, uint64_t low, uint64_t high) { 63 simulator->set_xreg(0, value); 64 simulator->set_xreg(1, low); 65 simulator->set_xreg(2, high); 66 67 simulator->RunFrom(function->target()); 68 printf("%ld %s between %ld and %ld\n", value, 69 simulator->xreg(0) ? "is" : "is not", 70 low, high); 71 72 simulator->ResetState(); 73 } 74 75 int main(void) { 76 // Create and initialize the assembler and the simulator. 77 byte assm_buf[BUF_SIZE]; 78 MacroAssembler masm(assm_buf, BUF_SIZE); 79 Decoder decoder; 80 Simulator simulator(&decoder); 81 82 // Generate the code for the example function. 83 Label check_bounds; 84 masm.Bind(&check_bounds); 85 GenerateCheckBounds(&masm); 86 masm.FinalizeCode(); 87 88 // Run the example function. 89 run_function(&simulator, &check_bounds, 546, 50, 1000); 90 run_function(&simulator, &check_bounds, 62, 100, 200); 91 run_function(&simulator, &check_bounds, 200, 100, 200); 92 93 return 0; 94 } 95 #endif 96
