| // 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. |
| |
| // PPC ABI source: |
| // http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.html |
| |
| // AIX Runtime process stack: |
| // https://www.ibm.com/support/knowledgecenter/ssw_aix_71/assembler/idalangref_runtime_process.html |
| asm( |
| #if defined(_AIX) |
| ".globl .PushAllRegistersAndIterateStack, hidden \n" |
| ".csect .text[PR] \n" |
| ".PushAllRegistersAndIterateStack: \n" |
| #else |
| ".globl PushAllRegistersAndIterateStack \n" |
| ".type PushAllRegistersAndIterateStack, %function \n" |
| ".hidden PushAllRegistersAndIterateStack \n" |
| "PushAllRegistersAndIterateStack: \n" |
| #endif |
| // Push all callee-saved registers. |
| // lr, TOC pointer, r16 to r31. 160 bytes. |
| // The parameter save area shall be allocated by the caller. 112 btes. |
| // At anytime, SP (r1) needs to be multiple of 16 (i.e. 16-aligned). |
| " mflr 0 \n" |
| " std 0, 16(1) \n" |
| #if defined(_AIX) |
| " std 2, 40(1) \n" |
| #else |
| " std 2, 24(1) \n" |
| #endif |
| " stdu 1, -256(1) \n" |
| " std 14, 112(1) \n" |
| " std 15, 120(1) \n" |
| " std 16, 128(1) \n" |
| " std 17, 136(1) \n" |
| " std 18, 144(1) \n" |
| " std 19, 152(1) \n" |
| " std 20, 160(1) \n" |
| " std 21, 168(1) \n" |
| " std 22, 176(1) \n" |
| " std 23, 184(1) \n" |
| " std 24, 192(1) \n" |
| " std 25, 200(1) \n" |
| " std 26, 208(1) \n" |
| " std 27, 216(1) \n" |
| " std 28, 224(1) \n" |
| " std 29, 232(1) \n" |
| " std 30, 240(1) \n" |
| " std 31, 248(1) \n" |
| // Pass 1st parameter (r3) unchanged (Stack*). |
| // Pass 2nd parameter (r4) unchanged (StackVisitor*). |
| // Save 3rd parameter (r5; IterateStackCallback). |
| " mr 6, 5 \n" |
| #if defined(_AIX) |
| // Set up TOC for callee. |
| " ld 2,8(5) \n" |
| // AIX uses function descriptors, which means that |
| // pointers to functions do not point to code, but |
| // instead point to metadata about them, hence |
| // need to deterrence. |
| " ld 6,0(6) \n" |
| #endif |
| // Pass 3rd parameter as sp (stack pointer). |
| " mr 5, 1 \n" |
| #if !defined(_AIX) |
| // Set up r12 to be equal to the callee address (in order for TOC |
| // relocation). Only needed on LE Linux. |
| " mr 12, 6 \n" |
| #endif |
| // Call the callback. |
| " mtctr 6 \n" |
| " bctrl \n" |
| // Discard all the registers. |
| " addi 1, 1, 256 \n" |
| // Restore lr. |
| " ld 0, 16(1) \n" |
| " mtlr 0 \n" |
| #if defined(_AIX) |
| // Restore TOC pointer. |
| " ld 2, 40(1) \n" |
| #else |
| " ld 2, 24(1) \n" |
| #endif |
| " blr \n"); |
