[thirdparty/glibc.git] / sysdeps / i386 / sysdep.h

/* Assembler macros for i386.
   Copyright (C) 1991-93,95,96,98,2002,2003,2005,2006,2011,2012
   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, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#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
/* 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.

   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)							      \
  STABS_CURRENT_FILE1("")						      \
  STABS_CURRENT_FILE(name)						      \
  ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name);				      \
  ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),@function)			      \
  .align ALIGNARG(4);							      \
  STABS_FUN(name)							      \
  C_LABEL(name)								      \
  cfi_startproc;							      \
  CALL_MCOUNT

#undef	END
#define END(name)							      \
  cfi_endproc;								      \
  ASM_SIZE_DIRECTIVE(name)						      \
  STABS_FUN_END(name)

#define ENTRY_CHK(name) ENTRY (name)
#define END_CHK(name) END (name)

#ifdef HAVE_CPP_ASM_DEBUGINFO
/* Disable that goop, because we just pass -g through to the assembler
   and it generates proper line number information directly.  */
# define STABS_CURRENT_FILE1(name)
# define STABS_CURRENT_FILE(name)
# define STABS_FUN(name)
# define STABS_FUN_END(name)
#else
/* Remove the following two lines once the gdb bug is fixed.  */
#define STABS_CURRENT_FILE(name)					      \
  STABS_CURRENT_FILE1 (#name)
#define STABS_CURRENT_FILE1(name)					      \
  1: .stabs name,100,0,0,1b;
/* Emit stabs definition lines.  We use F(0,1) and define t(0,1) as `int',
   the same way gcc does it.  */
#define STABS_FUN(name) STABS_FUN2(name, name##:F(0,1))
#define STABS_FUN2(name, namestr)					      \
  .stabs "int:t(0,1)=r(0,1);-2147483648;2147483647;",128,0,0,0;		      \
  .stabs #namestr,36,0,0,name;
#define STABS_FUN_END(name)						      \
  1: .stabs "",36,0,0,1b-name;
#endif

/* 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__ */
Commit	Line	Data
e75154a6	1	/* Assembler macros for i386.
0269750c	2	Copyright (C) 1991-93,95,96,98,2002,2003,2005,2006,2011,2012
11bf311e	3	Free Software Foundation, Inc.
2c6fe0bd UD	4	This file is part of the GNU C Library.
	5
	6	The GNU C Library is free software; you can redistribute it and/or
41bdb6e2 AJ	7	modify it under the terms of the GNU Lesser General Public
	8	License as published by the Free Software Foundation; either
	9	version 2.1 of the License, or (at your option) any later version.
2c6fe0bd UD	10
	11	The GNU C Library is distributed in the hope that it will be useful,
	12	but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
41bdb6e2	14	Lesser General Public License for more details.
2c6fe0bd	15
41bdb6e2 AJ	16	You should have received a copy of the GNU Lesser General Public
	17	License along with the GNU C Library; if not, write to the Free
	18	Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	19	02111-1307 USA. */
e75154a6 RM	20
	21	#include <sysdeps/generic/sysdep.h>
	22
314054ea JM	23	#include <features.h> /* For __GNUC_PREREQ. */
	24
	25	/* It is desirable that the names of PIC thunks match those used by
d4a54ac6 JM	26	GCC so that multiple copies are eliminated by the linker. Because
	27	GCC 4.6 and earlier use __i686 in the names, it is necessary to
	28	override that predefined macro. */
	29	#if defined __i686 && defined __ASSEMBLER__
	30	#undef __i686
	31	#define __i686 __i686
	32	#endif
314054ea JM	33
	34	#ifdef __ASSEMBLER__
	35	# if __GNUC_PREREQ (4, 7)
	36	# define GET_PC_THUNK(reg) __x86.get_pc_thunk.reg
	37	# else
	38	# define GET_PC_THUNK(reg) __i686.get_pc_thunk.reg
	39	# endif
b1da7dd9	40	#else
314054ea JM	41	# if __GNUC_PREREQ (4, 7)
	42	# define GET_PC_THUNK_STR(reg) "__x86.get_pc_thunk." #reg
	43	# else
	44	# define GET_PC_THUNK_STR(reg) "__i686.get_pc_thunk." #reg
	45	# endif
b1da7dd9 JM	46	#endif
b1da7dd9 JM	47
66715f83	48	#ifdef __ASSEMBLER__
e75154a6 RM	49
	50	/* Syntactic details of assembler. */
	51
e75154a6 RM	52	/* ELF uses byte-counts for .align, most others use log2 of count of bytes. */
	53	#define ALIGNARG(log2) 1<<log2
	54	/* For ELF we need the `.type' directive to make shared libs work right. */
	55	#define ASM_TYPE_DIRECTIVE(name,typearg) .type name,typearg;
ae828bc6	56	#define ASM_SIZE_DIRECTIVE(name) .size name,.-name;
e75154a6	57
e75154a6	58
ae828bc6 UD	59	/* Define an entry point visible from C.
	60
	61	There is currently a bug in gdb which prevents us from specifying
	62	incomplete stabs information. Fake some entries here which specify
	63	the current source file. */
e75154a6	64	#define ENTRY(name) \
ae828bc6 UD	65	STABS_CURRENT_FILE1("") \
ae828bc6 UD	66	STABS_CURRENT_FILE(name) \
e75154a6 RM	67	ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name); \
	68	ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),@function) \
	69	.align ALIGNARG(4); \
ae828bc6	70	STABS_FUN(name) \
e75154a6	71	C_LABEL(name) \
62d01985	72	cfi_startproc; \
e75154a6 RM	73	CALL_MCOUNT
e75154a6 RM	74
6ed0492f UD	75	#undef END
6ed0492f UD	76	#define END(name) \
62d01985	77	cfi_endproc; \
ae828bc6 UD	78	ASM_SIZE_DIRECTIVE(name) \
	79	STABS_FUN_END(name)
	80
3af48cbd L	81	#define ENTRY_CHK(name) ENTRY (name)
	82	#define END_CHK(name) END (name)
	83
e48f9638 RM	84	#ifdef HAVE_CPP_ASM_DEBUGINFO
	85	/* Disable that goop, because we just pass -g through to the assembler
	86	and it generates proper line number information directly. */
	87	# define STABS_CURRENT_FILE1(name)
	88	# define STABS_CURRENT_FILE(name)
	89	# define STABS_FUN(name)
	90	# define STABS_FUN_END(name)
	91	#else
ae828bc6 UD	92	/* Remove the following two lines once the gdb bug is fixed. */
	93	#define STABS_CURRENT_FILE(name) \
	94	STABS_CURRENT_FILE1 (#name)
	95	#define STABS_CURRENT_FILE1(name) \
	96	1: .stabs name,100,0,0,1b;
	97	/* Emit stabs definition lines. We use F(0,1) and define t(0,1) as `int',
	98	the same way gcc does it. */
	99	#define STABS_FUN(name) STABS_FUN2(name, name##:F(0,1))
	100	#define STABS_FUN2(name, namestr) \
	101	.stabs "int:t(0,1)=r(0,1);-2147483648;2147483647;",128,0,0,0; \
	102	.stabs #namestr,36,0,0,name;
	103	#define STABS_FUN_END(name) \
	104	1: .stabs "",36,0,0,1b-name;
e48f9638	105	#endif
6ed0492f	106
e75154a6 RM	107	/* If compiled for profiling, call `mcount' at the start of each function. */
	108	#ifdef PROF
	109	/* The mcount code relies on a normal frame pointer being on the stack
	110	to locate our caller, so push one just for its benefit. */
	111	#define CALL_MCOUNT \
cb8d9c93	112	pushl %ebp; cfi_adjust_cfa_offset (4); movl %esp, %ebp; \
62d01985 UD	113	cfi_def_cfa_register (ebp); call JUMPTARGET(mcount); \
62d01985 UD	114	popl %ebp; cfi_def_cfa (esp, 4);
e75154a6 RM	115	#else
	116	#define CALL_MCOUNT /* Do nothing. */
	117	#endif
	118
e75154a6 RM	119	/* Since C identifiers are not normally prefixed with an underscore
	120	on this system, the asm identifier `syscall_error' intrudes on the
	121	C name space. Make sure we use an innocuous name. */
	122	#define syscall_error __syscall_error
	123	#define mcount _mcount
e75154a6 RM	124
e75154a6 RM	125	#define PSEUDO(name, syscall_name, args) \
e75154a6	126	.globl syscall_error; \
ffa8d2a0 RM	127	lose: SYSCALL_PIC_SETUP \
ffa8d2a0 RM	128	jmp JUMPTARGET(syscall_error); \
e75154a6 RM	129	ENTRY (name) \
	130	DO_CALL (syscall_name, args); \
	131	jb lose
	132
cccda09f UD	133	#undef PSEUDO_END
cccda09f UD	134	#define PSEUDO_END(name) \
6ed0492f	135	END (name)
cccda09f	136
11bf311e	137	# define SETUP_PIC_REG(reg) \
b1da7dd9 JM	138	.ifndef GET_PC_THUNK(reg); \
	139	.section .gnu.linkonce.t.GET_PC_THUNK(reg),"ax",@progbits; \
	140	.globl GET_PC_THUNK(reg); \
	141	.hidden GET_PC_THUNK(reg); \
9a1d9254	142	.p2align 4; \
b1da7dd9 JM	143	.type GET_PC_THUNK(reg),@function; \
b1da7dd9 JM	144	GET_PC_THUNK(reg): \
1f708405 RM	145	movl (%esp), %e##reg; \
1f708405 RM	146	ret; \
b1da7dd9	147	.size GET_PC_THUNK(reg), . - GET_PC_THUNK(reg); \
1f708405 RM	148	.previous; \
1f708405 RM	149	.endif; \
b1da7dd9	150	call GET_PC_THUNK(reg)
1f708405 RM	151
	152	# define LOAD_PIC_REG(reg) \
	153	SETUP_PIC_REG(reg); addl $_GLOBAL_OFFSET_TABLE_, %e##reg
	154
9a1d9254 JM	155	#undef JUMPTARGET
	156	#ifdef PIC
	157	#define JUMPTARGET(name) name##@PLT
	158	#define SYSCALL_PIC_SETUP \
	159	pushl %ebx; \
	160	cfi_adjust_cfa_offset (4); \
	161	call 0f; \
	162	0: popl %ebx; \
	163	cfi_adjust_cfa_offset (-4); \
	164	addl $_GLOBAL_OFFSET_TABLE+[.-0b], %ebx;
	165
e75154a6 RM	166	#else
	167	#define JUMPTARGET(name) name
	168	#define SYSCALL_PIC_SETUP /* Nothing. */
	169	#endif
	170
ac16e905 UD	171	/* Local label name for asm code. */
ac16e905 UD	172	#ifndef L
ffa8d2a0	173	#define L(name) .L##name
ffa8d2a0	174	#endif
ac16e905	175
ceaa0c5d UD	176	#define atom_text_section .section ".text.atom", "ax"
ceaa0c5d UD	177
d8e0ca50 JM	178	#else /* __ASSEMBLER__ */
	179
	180	# define SETUP_PIC_REG_STR(reg) \
	181	".ifndef " GET_PC_THUNK_STR (reg) "\n" \
	182	".section .gnu.linkonce.t." GET_PC_THUNK_STR (reg) ",\"ax\",@progbits\n" \
	183	".globl " GET_PC_THUNK_STR (reg) "\n" \
	184	".hidden " GET_PC_THUNK_STR (reg) "\n" \
	185	".p2align 4\n" \
	186	".type " GET_PC_THUNK_STR (reg) ",@function\n" \
	187	GET_PC_THUNK_STR (reg) ":" \
	188	"movl (%%esp), %%e" #reg "\n" \
	189	"ret\n" \
	190	".size " GET_PC_THUNK_STR (reg) ", . - " GET_PC_THUNK_STR (reg) "\n" \
	191	".previous\n" \
	192	".endif\n" \
	193	"call " GET_PC_THUNK_STR (reg)
	194
	195	# define LOAD_PIC_REG_STR(reg) \
	196	SETUP_PIC_REG_STR (reg) "\naddl $_GLOBAL_OFFSET_TABLE_, %%e" #reg
	197
66715f83	198	#endif /* __ASSEMBLER__ */