| // Copyright 2014, 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 "examples.h" |
| |
| #define BUF_SIZE (4096) |
| #define __ masm-> |
| |
| void GenerateSwapInt32(MacroAssembler* masm) { |
| { |
| // In this scope the register x2 will be used by the macro-assembler |
| // as the stack pointer (via peek, poke, push, etc). |
| const Register old_stack_pointer = __ StackPointer(); |
| __ Mov(x2, __ StackPointer()); |
| __ SetStackPointer(x2); |
| |
| // This call to Claim is not 16-byte aligned and would have failed |
| // if the current stack pointer was sp. |
| __ Claim(8); |
| |
| __ Poke(w0, 0); |
| __ Poke(w1, 4); |
| __ Peek(w1, 0); |
| __ Peek(w0, 4); |
| |
| __ Drop(8); |
| |
| // Even if we didn't use the system stack pointer, sp might have been |
| // modified because the ABI forbids access to memory below the stack |
| // pointer. |
| __ Mov(old_stack_pointer, __ StackPointer()); |
| __ SetStackPointer(old_stack_pointer); |
| } |
| |
| // The stack pointer has now been switched back to sp. |
| __ Ret(); |
| } |
| |
| |
| #ifndef TEST_EXAMPLES |
| #ifdef VIXL_INCLUDE_SIMULATOR |
| int main(void) { |
| // Create and initialize the assembler and the simulator. |
| byte assm_buf[BUF_SIZE]; |
| MacroAssembler masm(assm_buf, BUF_SIZE); |
| Decoder decoder; |
| Simulator simulator(&decoder); |
| |
| // Generate the code for the example function. |
| Label swap_int32; |
| masm.Bind(&swap_int32); |
| GenerateSwapInt32(&masm); |
| masm.FinalizeCode(); |
| |
| // Run the example function. |
| simulator.set_wreg(0, 0x11111111); |
| simulator.set_wreg(1, 0x22222222); |
| |
| // clang-format off |
| printf("Before swap_int32:\n" |
| "x0 = 0x%" PRIx32 "\n" |
| "x1 = 0x%" PRIx32 "\n", |
| simulator.wreg(0), simulator.wreg(1)); |
| // clang-format on |
| |
| simulator.RunFrom(masm.GetLabelAddress<Instruction*>(&swap_int32)); |
| |
| // clang-format off |
| printf("After swap_int32:\n" |
| "x0 = 0x%" PRIx32 "\n" |
| "x1 = 0x%" PRIx32 "\n", |
| simulator.wreg(0), simulator.wreg(1)); |
| // clang-format on |
| |
| return 0; |
| } |
| #else |
| // Without the simulator there is nothing to test. |
| int main(void) { return 0; } |
| #endif // VIXL_INCLUDE_SIMULATOR |
| #endif // TEST_EXAMPLES |