| // Copyright 2015, ARM Limited |
| // 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 "vixl/a64/macro-assembler-a64.h" |
| #include "vixl/a64/instructions-a64.h" |
| #include "vixl/globals.h" |
| |
| using namespace vixl; |
| |
| static const int kDefaultInstructionCount = 100000; |
| |
| // This program focuses on emitting branch instructions. |
| // |
| // This code will emit a given number of branch immediate to the next |
| // instructions in a fixed size buffer, looping over the buffer if necessary. |
| // This code therefore focuses on Emit and label binding/patching. |
| int main(int argc, char* argv[]) { |
| int instructions = 0; |
| |
| switch (argc) { |
| case 1: instructions = kDefaultInstructionCount; break; |
| case 2: instructions = atoi(argv[1]); break; |
| default: |
| printf("Usage: %s [#instructions]\n", argv[0]); |
| exit(1); |
| } |
| |
| const int buffer_size = 256 * KBytes; |
| const int buffer_instruction_count = buffer_size / kInstructionSize; |
| MacroAssembler masm(buffer_size); |
| |
| #define __ masm. |
| // We emit a branch to the next instruction. |
| |
| int rounds = instructions / buffer_instruction_count; |
| for (int i = 0; i < rounds; ++i) { |
| { |
| InstructionAccurateScope scope(&masm, buffer_instruction_count); |
| for (int j = 0; j < buffer_instruction_count; ++j) { |
| Label target; |
| __ b(&target); |
| __ bind(&target); |
| } |
| } |
| masm.Reset(); |
| } |
| |
| int remaining = instructions % buffer_instruction_count; |
| { |
| InstructionAccurateScope scope(&masm, remaining); |
| for (int i = 0; i < remaining; ++i) { |
| Label target; |
| __ b(&target); |
| __ bind(&target); |
| } |
| } |
| |
| masm.FinalizeCode(); |
| |
| return 0; |
| } |