| // Copyright 2015, 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 GenerateCrc32(MacroAssembler* masm) { |
| // uint32_t crc32(const char *msg, size_t length) |
| // Argument location: |
| // msg (pointer) -> x0 |
| // length (integer) -> x1 |
| |
| // This example computes CRC32CB on an input array of a given size |
| // and returns the resulting checksum in w0. |
| |
| Label loop, end; |
| |
| // Move input array to temp register so we can re-use w0 as return register. |
| __ Mov(x2, x0); |
| |
| // Initial remainder for the checksum. If length=0, then this value will be |
| // returned. |
| __ Mov(w0, 0xffffffff); |
| |
| // Loop for iterating through the array, starting at msg[0]. |
| __ Bind(&loop); |
| |
| // If no more elements to process, then exit function. |
| __ Cbz(x1, &end); |
| __ Sub(x1, x1, 1); |
| |
| // Compute checksum for msg[i]. |
| __ Ldrb(w3, MemOperand(x2, 1, PostIndex)); |
| __ Crc32b(w0, w0, w3); |
| __ B(&loop); |
| |
| __ Bind(&end); |
| |
| __ Ret(); |
| } |
| |
| #ifndef TEST_EXAMPLES |
| |
| void runExample(const char* msg) { |
| MacroAssembler masm; |
| |
| // Generate the code for the example function. |
| Label func; |
| masm.Bind(&func); |
| GenerateCrc32(&masm); |
| masm.FinalizeCode(); |
| |
| #ifdef VIXL_INCLUDE_SIMULATOR_AARCH64 |
| // Run example function in the simulator. |
| uintptr_t msg_addr = reinterpret_cast<uintptr_t>(msg); |
| size_t msg_size = strlen(msg); |
| Decoder decoder; |
| Simulator simulator(&decoder); |
| simulator.WriteXRegister(0, msg_addr); |
| simulator.WriteXRegister(1, msg_size); |
| simulator.RunFrom(masm.GetLabelAddress<Instruction*>(&func)); |
| printf("crc32(\"%s\")=0x%x\n", msg, simulator.ReadWRegister(0)); |
| #else |
| // Run example function natively. |
| printf("Not yet implemented.\n"); |
| USE(msg); |
| #endif // VIXL_INCLUDE_SIMULATOR_AARCH64 |
| } |
| |
| |
| int main(void) { |
| runExample("Hello World!"); |
| runExample("do"); |
| runExample("1"); |
| runExample(""); |
| |
| return 0; |
| } |
| #endif // TEST_EXAMPLES |