glibc/sysdeps/x86_64/sysdep.h
2012-02-09 23:18:22 +00:00

99 lines
3.4 KiB
C

/* Assembler macros for x86-64.
Copyright (C) 2001, 2002, 2003, 2011, 2012 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>
#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
/* For ELF we need the `.type' directive to make shared libs work right. */
#define ASM_TYPE_DIRECTIVE(name,typearg) .type name,typearg;
#define ASM_SIZE_DIRECTIVE(name) .size name,.-name;
/* Define an entry point visible from C. */
#define ENTRY(name) \
ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name); \
ASM_TYPE_DIRECTIVE (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 \
pushq %rbp; \
cfi_adjust_cfa_offset(8); \
movq %rsp, %rbp; \
cfi_def_cfa_register(%rbp); \
call JUMPTARGET(mcount); \
popq %rbp; \
cfi_def_cfa(rsp,8);
#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) \
lose: \
jmp JUMPTARGET(syscall_error) \
.globl syscall_error; \
ENTRY (name) \
DO_CALL (syscall_name, args); \
jb lose
#undef PSEUDO_END
#define PSEUDO_END(name) \
END (name)
#undef JUMPTARGET
#ifdef PIC
#define JUMPTARGET(name) name##@PLT
#else
#define JUMPTARGET(name) name
#endif
/* Local label name for asm code. */
#ifndef L
/* ELF-like local names start with `.L'. */
# define L(name) .L##name
#endif
#define atom_text_section .section ".text.atom", "ax"
#endif /* __ASSEMBLER__ */