2739cb00b381fe63f58135d78498c6955eb93736
[kopensolaris-gnu/glibc.git] / sysdeps / i386 / sysdep.h
1 /* Assembler macros for i386.
2    Copyright (C) 1991-93,95,96,98,2002,2003,2005 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, write to the Free
17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18    02111-1307 USA.  */
19
20 #include <sysdeps/generic/sysdep.h>
21
22 #ifdef  __ASSEMBLER__
23
24 /* Syntactic details of assembler.  */
25
26 #ifdef HAVE_ELF
27
28 /* ELF uses byte-counts for .align, most others use log2 of count of bytes.  */
29 #define ALIGNARG(log2) 1<<log2
30 /* For ELF we need the `.type' directive to make shared libs work right.  */
31 #define ASM_TYPE_DIRECTIVE(name,typearg) .type name,typearg;
32 #define ASM_SIZE_DIRECTIVE(name) .size name,.-name;
33
34 /* In ELF C symbols are asm symbols.  */
35 #undef  NO_UNDERSCORES
36 #define NO_UNDERSCORES
37
38 #else
39
40 #define ALIGNARG(log2) log2
41 #define ASM_TYPE_DIRECTIVE(name,type)   /* Nothing is specified.  */
42 #define ASM_SIZE_DIRECTIVE(name)        /* Nothing is specified.  */
43
44 #endif
45
46
47 /* Define an entry point visible from C.
48
49    There is currently a bug in gdb which prevents us from specifying
50    incomplete stabs information.  Fake some entries here which specify
51    the current source file.  */
52 #define ENTRY(name)                                                           \
53   STABS_CURRENT_FILE1("")                                                     \
54   STABS_CURRENT_FILE(name)                                                    \
55   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name);                                   \
56   ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),@function)                          \
57   .align ALIGNARG(4);                                                         \
58   STABS_FUN(name)                                                             \
59   C_LABEL(name)                                                               \
60   cfi_startproc;                                                              \
61   CALL_MCOUNT
62
63 #undef  END
64 #define END(name)                                                             \
65   cfi_endproc;                                                                \
66   ASM_SIZE_DIRECTIVE(name)                                                    \
67   STABS_FUN_END(name)
68
69 #ifdef HAVE_CPP_ASM_DEBUGINFO
70 /* Disable that goop, because we just pass -g through to the assembler
71    and it generates proper line number information directly.  */
72 # define STABS_CURRENT_FILE1(name)
73 # define STABS_CURRENT_FILE(name)
74 # define STABS_FUN(name)
75 # define STABS_FUN_END(name)
76 #else
77 /* Remove the following two lines once the gdb bug is fixed.  */
78 #define STABS_CURRENT_FILE(name)                                              \
79   STABS_CURRENT_FILE1 (#name)
80 #define STABS_CURRENT_FILE1(name)                                             \
81   1: .stabs name,100,0,0,1b;
82 /* Emit stabs definition lines.  We use F(0,1) and define t(0,1) as `int',
83    the same way gcc does it.  */
84 #define STABS_FUN(name) STABS_FUN2(name, name##:F(0,1))
85 #define STABS_FUN2(name, namestr)                                             \
86   .stabs "int:t(0,1)=r(0,1);-2147483648;2147483647;",128,0,0,0;               \
87   .stabs #namestr,36,0,0,name;
88 #define STABS_FUN_END(name)                                                   \
89   1: .stabs "",36,0,0,1b-name;
90 #endif
91
92 /* If compiled for profiling, call `mcount' at the start of each function.  */
93 #ifdef  PROF
94 /* The mcount code relies on a normal frame pointer being on the stack
95    to locate our caller, so push one just for its benefit.  */
96 #define CALL_MCOUNT \
97   pushl %ebp; cfi_adjust_cfa_offset (4); movl %esp, %ebp; \
98   cfi_def_cfa_register (ebp); call JUMPTARGET(mcount); \
99   popl %ebp; cfi_def_cfa (esp, 4);
100 #else
101 #define CALL_MCOUNT             /* Do nothing.  */
102 #endif
103
104 #ifdef  NO_UNDERSCORES
105 /* Since C identifiers are not normally prefixed with an underscore
106    on this system, the asm identifier `syscall_error' intrudes on the
107    C name space.  Make sure we use an innocuous name.  */
108 #define syscall_error   __syscall_error
109 #define mcount          _mcount
110 #endif
111
112 #define PSEUDO(name, syscall_name, args)                                      \
113   .globl syscall_error;                                                       \
114 lose: SYSCALL_PIC_SETUP                                                       \
115   jmp JUMPTARGET(syscall_error);                                              \
116   ENTRY (name)                                                                \
117   DO_CALL (syscall_name, args);                                               \
118   jb lose
119
120 #undef  PSEUDO_END
121 #define PSEUDO_END(name)                                                      \
122   END (name)
123
124 #undef JUMPTARGET
125 #ifdef PIC
126 #define JUMPTARGET(name)        name##@PLT
127 #define SYSCALL_PIC_SETUP \
128     pushl %ebx;                                                               \
129     cfi_adjust_cfa_offset (4);                                                \
130     call 0f;                                                                  \
131 0:  popl %ebx;                                                                \
132     cfi_adjust_cfa_offset (-4);                                               \
133     addl $_GLOBAL_OFFSET_TABLE+[.-0b], %ebx;
134
135 # ifndef HAVE_HIDDEN
136 #  define SETUP_PIC_REG(reg) \
137   call 1f;                                                                    \
138   .subsection 1;                                                              \
139 1:movl (%esp), %e##reg;                                                       \
140   ret;                                                                        \
141   .previous
142 # else
143 #  define SETUP_PIC_REG(reg) \
144   .ifndef __i686.get_pc_thunk.reg;                                            \
145   .section .gnu.linkonce.t.__i686.get_pc_thunk.reg,"ax",@progbits;            \
146   .globl __i686.get_pc_thunk.reg;                                             \
147   .hidden __i686.get_pc_thunk.reg;                                            \
148   .type __i686.get_pc_thunk.reg,@function;                                    \
149 __i686.get_pc_thunk.reg:                                                      \
150   movl (%esp), %e##reg;                                                       \
151   ret;                                                                        \
152   .size __i686.get_pc_thunk.reg, . - __i686.get_pc_thunk.reg;                 \
153   .previous;                                                                  \
154   .endif;                                                                     \
155   call __i686.get_pc_thunk.reg
156 # endif
157
158 # define LOAD_PIC_REG(reg) \
159   SETUP_PIC_REG(reg); addl $_GLOBAL_OFFSET_TABLE_, %e##reg
160
161 #else
162 #define JUMPTARGET(name)        name
163 #define SYSCALL_PIC_SETUP       /* Nothing.  */
164 #endif
165
166 /* Local label name for asm code. */
167 #ifndef L
168 #ifdef HAVE_ELF
169 #define L(name)         .L##name
170 #else
171 #define L(name)         name
172 #endif
173 #endif
174
175 #endif  /* __ASSEMBLER__ */