| // Copyright 2020 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // Push all callee-saved registers to get them on the stack for conservative |
| // stack scanning. |
| // |
| // See asm/x64/push_registers_clang.cc for why the function is not generated |
| // using clang. |
| // |
| // Do not depend on V8_TARGET_OS_* defines as some embedders may override the |
| // GN toolchain (e.g. ChromeOS) and not provide them. |
| |
| // We maintain 16-byte alignment. |
| // |
| // Calling convention source: |
| // https://en.wikipedia.org/wiki/Calling_convention#ARM_(A64) |
| |
| asm( |
| #if defined(__APPLE__) |
| ".globl _PushAllRegistersAndIterateStack \n" |
| ".private_extern _PushAllRegistersAndIterateStack \n" |
| ".p2align 2 \n" |
| "_PushAllRegistersAndIterateStack: \n" |
| #else // !defined(__APPLE__) |
| ".globl PushAllRegistersAndIterateStack \n" |
| #if !defined(_WIN64) |
| ".type PushAllRegistersAndIterateStack, %function \n" |
| ".hidden PushAllRegistersAndIterateStack \n" |
| #endif // !defined(_WIN64) |
| ".p2align 2 \n" |
| "PushAllRegistersAndIterateStack: \n" |
| #endif // !defined(__APPLE__) |
| // x19-x29 are callee-saved. |
| " stp x19, x20, [sp, #-16]! \n" |
| " stp x21, x22, [sp, #-16]! \n" |
| " stp x23, x24, [sp, #-16]! \n" |
| " stp x25, x26, [sp, #-16]! \n" |
| " stp x27, x28, [sp, #-16]! \n" |
| " stp fp, lr, [sp, #-16]! \n" |
| // Maintain frame pointer. |
| " mov fp, sp \n" |
| // Pass 1st parameter (x0) unchanged (Stack*). |
| // Pass 2nd parameter (x1) unchanged (StackVisitor*). |
| // Save 3rd parameter (x2; IterateStackCallback) |
| " mov x7, x2 \n" |
| // Pass 3rd parameter as sp (stack pointer). |
| " mov x2, sp \n" |
| " blr x7 \n" |
| // Load return address. |
| " ldr lr, [sp, #8] \n" |
| // Restore frame pointer and pop all callee-saved registers. |
| " ldr fp, [sp], #96 \n" |
| " ret \n"); |
