// Copyright 2014, VIXL authors // All rights reserved. // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are met: // // * Redistributions of source code must retain the above copyright notice, // this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above copyright notice, // this list of conditions and the following disclaimer in the documentation // and/or other materials provided with the distribution. // * Neither the name of ARM Limited nor the names of its contributors may be // used to endorse or promote products derived from this software without // specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. #include "examples.h" #define __ masm-> void GenerateFactorialRec(MacroAssembler* masm) { // uint64_t factorial_rec(uint64_t n) // Argument location: // n -> x0 Label entry, input_is_zero; __ Bind(&entry); // Check for the stopping condition: the input number is null. __ Cbz(x0, &input_is_zero); __ Mov(x1, x0); __ Sub(x0, x0, 1); __ Push(x1, lr); __ Bl(&entry); // Recursive call factorial_rec(n - 1). __ Pop(lr, x1); __ Mul(x0, x0, x1); __ Ret(); __ Bind(&input_is_zero); __ Mov(x0, 1); __ Ret(); } #ifndef TEST_EXAMPLES #ifdef VIXL_INCLUDE_SIMULATOR_AARCH64 int main(void) { MacroAssembler masm; Decoder decoder; Simulator simulator(&decoder); // Generate the code for the example function. Label factorial_rec; masm.Bind(&factorial_rec); GenerateFactorialRec(&masm); masm.FinalizeCode(); // Run the example function. uint64_t input_val = 16; simulator.WriteXRegister(0, input_val); simulator.RunFrom(masm.GetLabelAddress(&factorial_rec)); printf("factorial(%" PRIu64 ") = %" PRId64 "\n", input_val, simulator.ReadXRegister(0)); return 0; } #else // Without the simulator there is nothing to test. int main(void) { return 0; } #endif // VIXL_INCLUDE_SIMULATOR_AARCH64 #endif // TEST_EXAMPLES