libpthread/nptl/sysdeps/i386/sysdep.h

   1 /* Assembler macros for i386.
   2    Copyright (C) 1991-93,95,96,98,2002,2003,2005,2006
   3    Free Software Foundation, Inc.
   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
   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.
  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
  14    Lesser General Public License for more details.
  15
  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.  */
  20
  21 #include <sysdeps/generic/sysdep.h>
  22
  23 #ifdef  __ASSEMBLER__
  24
  25 /* Syntactic details of assembler.  */
  26
  27 /* ELF uses byte-counts for .align, most others use log2 of count of bytes.  */
  28 #define ALIGNARG(log2) 1<<log2
  29 /* For ELF we need the `.type' directive to make shared libs work right.  */
  30 #define ASM_TYPE_DIRECTIVE(name,typearg) .type name,typearg;
  31 #define ASM_SIZE_DIRECTIVE(name) .size name,.-name;
  32
  33 /* In ELF C symbols are asm symbols.  */
  34 #undef  NO_UNDERSCORES
  35 #define NO_UNDERSCORES
  36
  37 /* Define an entry point visible from C.
  38
  39    There is currently a bug in gdb which prevents us from specifying
  40    incomplete stabs information.  Fake some entries here which specify
  41    the current source file.  */
  42 #define ENTRY(name)                                                           \
  43   STABS_CURRENT_FILE1("")                                                     \
  44   STABS_CURRENT_FILE(name)                                                    \
  45   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name);                                   \
  46   ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),@function)                          \
  47   .align ALIGNARG(4);                                                         \
  48   STABS_FUN(name)                                                             \
  49   C_LABEL(name)                                                               \
  50   cfi_startproc;                                                              \
  51   CALL_MCOUNT
  52
  53 #undef  END
  54 #define END(name)                                                             \
  55   cfi_endproc;                                                                \
  56   ASM_SIZE_DIRECTIVE(name)                                                    \
  57   STABS_FUN_END(name)
  58
  59 #ifdef HAVE_CPP_ASM_DEBUGINFO
  60 /* Disable that goop, because we just pass -g through to the assembler
  61    and it generates proper line number information directly.  */
  62 # define STABS_CURRENT_FILE1(name)
  63 # define STABS_CURRENT_FILE(name)
  64 # define STABS_FUN(name)
  65 # define STABS_FUN_END(name)
  66 #else
  67 /* Remove the following two lines once the gdb bug is fixed.  */
  68 #define STABS_CURRENT_FILE(name)                                              \
  69   STABS_CURRENT_FILE1 (#name)
  70 #define STABS_CURRENT_FILE1(name)                                             \
  71   1: .stabs name,100,0,0,1b;
  72 /* Emit stabs definition lines.  We use F(0,1) and define t(0,1) as `int',
  73    the same way gcc does it.  */
  74 #define STABS_FUN(name) STABS_FUN2(name, name##:F(0,1))
  75 #define STABS_FUN2(name, namestr)                                             \
  76   .stabs "int:t(0,1)=r(0,1);-2147483648;2147483647;",128,0,0,0;               \
  77   .stabs #namestr,36,0,0,name;
  78 #define STABS_FUN_END(name)                                                   \
  79   1: .stabs "",36,0,0,1b-name;
  80 #endif
  81
  82 /* If compiled for profiling, call `mcount' at the start of each function.  */
  83 #ifdef  PROF
  84 /* The mcount code relies on a normal frame pointer being on the stack
  85    to locate our caller, so push one just for its benefit.  */
  86 #define CALL_MCOUNT \
  87   pushl %ebp; cfi_adjust_cfa_offset (4); movl %esp, %ebp; \
  88   cfi_def_cfa_register (ebp); call JUMPTARGET(mcount); \
  89   popl %ebp; cfi_def_cfa (esp, 4);
  90 #else
  91 #define CALL_MCOUNT             /* Do nothing.  */
  92 #endif
  93
  94 #ifdef  NO_UNDERSCORES
  95 /* Since C identifiers are not normally prefixed with an underscore
  96    on this system, the asm identifier `syscall_error' intrudes on the
  97    C name space.  Make sure we use an innocuous name.  */
  98 #define syscall_error   __syscall_error
  99 #define mcount          _mcount
 100 #endif
 101
 102 #define PSEUDO(name, syscall_name, args)                                      \
 103   .globl syscall_error;                                                       \
 104 lose: SYSCALL_PIC_SETUP                                                       \
 105   jmp JUMPTARGET(syscall_error);                                              \
 106   ENTRY (name)                                                                \
 107   DO_CALL (syscall_name, args);                                               \
 108   jb lose
 109
 110 #undef  PSEUDO_END
 111 #define PSEUDO_END(name)                                                      \
 112   END (name)
 113
 114 #undef JUMPTARGET
 115 #ifdef PIC
 116 #define JUMPTARGET(name)        name##@PLT
 117 #define SYSCALL_PIC_SETUP \
 118     pushl %ebx;                                                               \
 119     cfi_adjust_cfa_offset (4);                                                \
 120     call 0f;                                                                  \
 121 0:  popl %ebx;                                                                \
 122     cfi_adjust_cfa_offset (-4);                                               \
 123     addl $_GLOBAL_OFFSET_TABLE+[.-0b], %ebx;
 124
 125 # define SETUP_PIC_REG(reg) \
 126   .ifndef __i686.get_pc_thunk.reg;                                            \
 127   .section .gnu.linkonce.t.__i686.get_pc_thunk.reg,"ax",@progbits;            \
 128   .globl __i686.get_pc_thunk.reg;                                             \
 129   .hidden __i686.get_pc_thunk.reg;                                            \
 130   .type __i686.get_pc_thunk.reg,@function;                                    \
 131 __i686.get_pc_thunk.reg:                                                      \
 132   movl (%esp), %e##reg;                                                       \
 133   ret;                                                                        \
 134   .size __i686.get_pc_thunk.reg, . - __i686.get_pc_thunk.reg;                 \
 135   .previous;                                                                  \
 136   .endif;                                                                     \
 137   call __i686.get_pc_thunk.reg
 138
 139 # define LOAD_PIC_REG(reg) \
 140   SETUP_PIC_REG(reg); addl $_GLOBAL_OFFSET_TABLE_, %e##reg
 141
 142 #else
 143 #define JUMPTARGET(name)        name
 144 #define SYSCALL_PIC_SETUP       /* Nothing.  */
 145 #endif
 146
 147 /* Local label name for asm code. */
 148 #ifndef L
 149 #ifdef HAVE_ELF
 150 #define L(name)         .L##name
 151 #else
 152 #define L(name)         name
 153 #endif
 154 #endif
 155
 156 #endif  /* __ASSEMBLER__ */