sysdeps/x86_64/sysdep.h

   1 /* Assembler macros for x86-64.
   2    Copyright (C) 2001, 2002, 2003 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 #define ENTRY(name)                                                           \
  49   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name);                                   \
  50   ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),@function)                          \
  51   .align ALIGNARG(4);                                                         \
  52   C_LABEL(name)                                                               \
  53   cfi_startproc;                                                              \
  54   CALL_MCOUNT
  55
  56 #undef  END
  57 #define END(name)                                                             \
  58   cfi_endproc;                                                                \
  59   ASM_SIZE_DIRECTIVE(name)
  60
  61 /* If compiled for profiling, call `mcount' at the start of each function.  */
  62 #ifdef  PROF
  63 /* The mcount code relies on a normal frame pointer being on the stack
  64    to locate our caller, so push one just for its benefit.  */
  65 #define CALL_MCOUNT                                                          \
  66   pushq %rbp;                                                                \
  67   cfi_adjust_cfa_offset(8);                                                  \
  68   movq %rsp, %rbp;                                                           \
  69   cfi_def_cfa_register(%rbp);                                                \
  70   call JUMPTARGET(mcount);                                                   \
  71   popq %rbp;                                                                 \
  72   cfi_def_cfa(rsp,8);
  73 #else
  74 #define CALL_MCOUNT             /* Do nothing.  */
  75 #endif
  76
  77 #ifdef  NO_UNDERSCORES
  78 /* Since C identifiers are not normally prefixed with an underscore
  79    on this system, the asm identifier `syscall_error' intrudes on the
  80    C name space.  Make sure we use an innocuous name.  */
  81 #define syscall_error   __syscall_error
  82 #define mcount          _mcount
  83 #endif
  84
  85 #define PSEUDO(name, syscall_name, args)                                      \
  86 lose:                                                                         \
  87   jmp JUMPTARGET(syscall_error)                                               \
  88   .globl syscall_error;                                                       \
  89   ENTRY (name)                                                                \
  90   DO_CALL (syscall_name, args);                                               \
  91   jb lose
  92
  93 #undef  PSEUDO_END
  94 #define PSEUDO_END(name)                                                      \
  95   END (name)
  96
  97 #undef JUMPTARGET
  98 #ifdef PIC
  99 #define JUMPTARGET(name)        name##@PLT
 100 #else
 101 #define JUMPTARGET(name)        name
 102 #endif
 103
 104 /* Local label name for asm code. */
 105 #ifndef L
 106 # ifdef HAVE_ELF
 107 /* ELF-like local names start with `.L'.  */
 108 #  define L(name)       .L##name
 109 # else
 110 #  define L(name)       name
 111 # endif
 112 #endif
 113
 114 #endif  /* __ASSEMBLER__ */