/* Assembler macros for i386. Copyright (C) 1991-2020 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see . */ #include #include /* For __GNUC_PREREQ. */ /* It is desirable that the names of PIC thunks match those used by GCC so that multiple copies are eliminated by the linker. Because GCC 4.6 and earlier use __i686 in the names, it is necessary to override that predefined macro. */ #if defined __i686 && defined __ASSEMBLER__ #undef __i686 #define __i686 __i686 #endif #ifdef __ASSEMBLER__ # define GET_PC_THUNK(reg) __x86.get_pc_thunk.reg #else # define GET_PC_THUNK_STR(reg) "__x86.get_pc_thunk." #reg #endif #ifdef __ASSEMBLER__ /* Syntactic details of assembler. */ /* If compiled for profiling, call `mcount' at the start of each function. */ #ifdef PROF /* The mcount code relies on a normal frame pointer being on the stack to locate our caller, so push one just for its benefit. */ #define CALL_MCOUNT \ pushl %ebp; cfi_adjust_cfa_offset (4); movl %esp, %ebp; \ cfi_def_cfa_register (ebp); call JUMPTARGET(mcount); \ popl %ebp; cfi_def_cfa (esp, 4); #else #define CALL_MCOUNT /* Do nothing. */ #endif #define PSEUDO(name, syscall_name, args) \ .globl syscall_error; \ lose: SYSCALL_PIC_SETUP \ jmp JUMPTARGET(syscall_error); \ ENTRY (name) \ DO_CALL (syscall_name, args); \ jb lose # define SETUP_PIC_REG(reg) \ .ifndef GET_PC_THUNK(reg); \ .section .text.GET_PC_THUNK(reg),"axG",@progbits,GET_PC_THUNK(reg),comdat; \ .globl GET_PC_THUNK(reg); \ .hidden GET_PC_THUNK(reg); \ .p2align 4; \ .type GET_PC_THUNK(reg),@function; \ GET_PC_THUNK(reg): \ movl (%esp), %e##reg; \ ret; \ .size GET_PC_THUNK(reg), . - GET_PC_THUNK(reg); \ .previous; \ .endif; \ call GET_PC_THUNK(reg) # define LOAD_PIC_REG(reg) \ SETUP_PIC_REG(reg); addl $_GLOBAL_OFFSET_TABLE_, %e##reg #undef JUMPTARGET #ifdef PIC #define JUMPTARGET(name) name##@PLT #define SYSCALL_PIC_SETUP \ pushl %ebx; \ cfi_adjust_cfa_offset (4); \ call 0f; \ 0: popl %ebx; \ cfi_adjust_cfa_offset (-4); \ addl $_GLOBAL_OFFSET_TABLE_+[.-0b], %ebx; #else #define JUMPTARGET(name) name #define SYSCALL_PIC_SETUP /* Nothing. */ #endif #else /* __ASSEMBLER__ */ # define SETUP_PIC_REG_STR(reg) \ ".ifndef " GET_PC_THUNK_STR (reg) "\n" \ ".section .text." GET_PC_THUNK_STR (reg) ",\"axG\",@progbits," \ GET_PC_THUNK_STR (reg) ",comdat\n" \ ".globl " GET_PC_THUNK_STR (reg) "\n" \ ".hidden " GET_PC_THUNK_STR (reg) "\n" \ ".p2align 4\n" \ ".type " GET_PC_THUNK_STR (reg) ",@function\n" \ GET_PC_THUNK_STR (reg) ":" \ "movl (%%esp), %%e" #reg "\n" \ "ret\n" \ ".size " GET_PC_THUNK_STR (reg) ", . - " GET_PC_THUNK_STR (reg) "\n" \ ".previous\n" \ ".endif\n" \ "call " GET_PC_THUNK_STR (reg) # define LOAD_PIC_REG_STR(reg) \ SETUP_PIC_REG_STR (reg) "\naddl $_GLOBAL_OFFSET_TABLE_, %%e" #reg #endif /* __ASSEMBLER__ */