| /* Assembler macros for i386. |
| Copyright (C) 1991-2014 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 |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <sysdeps/generic/sysdep.h> |
| |
| #include <features.h> /* 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__ |
| # if __GNUC_PREREQ (4, 7) |
| # define GET_PC_THUNK(reg) __x86.get_pc_thunk.reg |
| # else |
| # define GET_PC_THUNK(reg) __i686.get_pc_thunk.reg |
| # endif |
| #else |
| # if __GNUC_PREREQ (4, 7) |
| # define GET_PC_THUNK_STR(reg) "__x86.get_pc_thunk." #reg |
| # else |
| # define GET_PC_THUNK_STR(reg) "__i686.get_pc_thunk." #reg |
| # endif |
| #endif |
| |
| #ifdef __ASSEMBLER__ |
| |
| /* Syntactic details of assembler. */ |
| |
| /* ELF uses byte-counts for .align, most others use log2 of count of bytes. */ |
| #define ALIGNARG(log2) 1<<log2 |
| #define ASM_SIZE_DIRECTIVE(name) .size name,.-name; |
| |
| |
| /* Define an entry point visible from C. |
| |
| There is currently a bug in gdb which prevents us from specifying |
| incomplete stabs information. Fake some entries here which specify |
| the current source file. */ |
| #define ENTRY(name) \ |
| .globl C_SYMBOL_NAME(name); \ |
| .type C_SYMBOL_NAME(name),@function; \ |
| .align ALIGNARG(4); \ |
| C_LABEL(name) \ |
| cfi_startproc; \ |
| CALL_MCOUNT |
| |
| #undef END |
| #define END(name) \ |
| cfi_endproc; \ |
| ASM_SIZE_DIRECTIVE(name) |
| |
| #define ENTRY_CHK(name) ENTRY (name) |
| #define END_CHK(name) END (name) |
| |
| /* 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 |
| |
| /* Since C identifiers are not normally prefixed with an underscore |
| on this system, the asm identifier `syscall_error' intrudes on the |
| C name space. Make sure we use an innocuous name. */ |
| #define syscall_error __syscall_error |
| #define mcount _mcount |
| |
| #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 |
| |
| #undef PSEUDO_END |
| #define PSEUDO_END(name) \ |
| END (name) |
| |
| # define SETUP_PIC_REG(reg) \ |
| .ifndef GET_PC_THUNK(reg); \ |
| .section .gnu.linkonce.t.GET_PC_THUNK(reg),"ax",@progbits; \ |
| .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 |
| |
| /* Local label name for asm code. */ |
| #ifndef L |
| #define L(name) .L##name |
| #endif |
| |
| #define atom_text_section .section ".text.atom", "ax" |
| |
| #else /* __ASSEMBLER__ */ |
| |
| # define SETUP_PIC_REG_STR(reg) \ |
| ".ifndef " GET_PC_THUNK_STR (reg) "\n" \ |
| ".section .gnu.linkonce.t." GET_PC_THUNK_STR (reg) ",\"ax\",@progbits\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__ */ |
