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 GenerateFactorial(MacroAssembler* masm) { 33 // uint64_t factorial(uint64_t n) 34 // Argument location: 35 // n -> x0 36 37 Label loop, end; 38 39 __ Mov(x1, x0); 40 __ Mov(x0, 1); // Use x0 as the accumulator. 41 42 __ Cbz(x1, &end); // Nothing to do if the input is null. 43 44 __ Bind(&loop); 45 __ Mul(x0, x0, x1); 46 __ Sub(x1, x1, 1); 47 __ Cbnz(x1, &loop); 48 49 __ Bind(&end); 50 // The return value is in x0. 51 __ Ret(); 52 } 53 54 55 #ifndef TEST_EXAMPLES 56 int main(void) { 57 // Create and initialize the assembler and the simulator. 58 byte assm_buf[BUF_SIZE]; 59 MacroAssembler masm(assm_buf, BUF_SIZE); 60 Decoder decoder; 61 Simulator simulator(&decoder); 62 63 // Generate the code for the example function. 64 Label factorial; 65 masm.Bind(&factorial); 66 GenerateFactorial(&masm); 67 masm.FinalizeCode(); 68 69 // Run the example function. 70 uint64_t input_val = 16; 71 simulator.set_xreg(0, input_val); 72 simulator.RunFrom(factorial.target()); 73 printf("factorial(%ld) = %ld\n", input_val, simulator.xreg(0)); 74 75 return 0; 76 } 77 #endif 78
