sysdep.h 3.5 KB

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  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. The GNU C Library is free software; you can redistribute it and/or
  5. modify it under the terms of the GNU Lesser General Public
  6. License as published by the Free Software Foundation; either
  7. version 2.1 of the License, or (at your option) any later version.
  8. The GNU C Library is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. Lesser General Public License for more details.
  12. You should have received a copy of the GNU Lesser General Public
  13. License along with the GNU C Library; if not, write to the Free
  14. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  15. 02111-1307 USA. */
  16. #ifdef __ASSEMBLER__
  17. /* Syntactic details of assembler. */
  18. #ifdef HAVE_ELF
  19. /* ELF uses byte-counts for .align, most others use log2 of count of bytes. */
  20. #define ALIGNARG(log2) (1 << (log2))
  21. /* For ELF we need the `.type' directive to make shared libs work right. */
  22. #define ASM_TYPE_DIRECTIVE(name, typearg) .type name,typearg;
  23. #define ASM_SIZE_DIRECTIVE(name) .size name,.-name;
  24. /* In ELF C symbols are asm symbols. */
  25. #undef NO_UNDERSCORES
  26. #define NO_UNDERSCORES
  27. #else
  28. #define ALIGNARG(log2) (log2)
  29. #define ASM_TYPE_DIRECTIVE(name, type) /* Nothing is specified. */
  30. #define ASM_SIZE_DIRECTIVE(name) /* Nothing is specified. */
  31. #endif
  32. /* Define an entry point visible from C. */
  33. #define ENTRY(name) \
  34. ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name); \
  35. ASM_TYPE_DIRECTIVE(C_SYMBOL_NAME(name), @function); \
  36. .align ALIGNARG(4); \
  37. C_LABEL(name); \
  38. cfi_startproc; \
  39. CALL_MCOUNT
  40. #undef END
  41. #define END(name) \
  42. cfi_endproc; \
  43. ASM_SIZE_DIRECTIVE(name)
  44. /* If compiled for profiling, call `mcount' at the start of each function. */
  45. #ifdef PROF
  46. /* The mcount code relies on a normal frame pointer being on the stack
  47. to locate our caller, so push one just for its benefit. */
  48. #define CALL_MCOUNT \
  49. pushq %rbp; \
  50. cfi_adjust_cfa_offset(8); \
  51. movq %rsp, %rbp; \
  52. cfi_def_cfa_register(%rbp); \
  53. call JUMPTARGET(mcount); \
  54. popq %rbp; \
  55. cfi_def_cfa(rsp, 8);
  56. #else
  57. #define CALL_MCOUNT /* Do nothing. */
  58. #endif
  59. #ifdef NO_UNDERSCORES
  60. /* Since C identifiers are not normally prefixed with an underscore
  61. on this system, the asm identifier `syscall_error' intrudes on the
  62. C name space. Make sure we use an innocuous name. */
  63. #define syscall_error __syscall_error
  64. #define mcount _mcount
  65. #endif
  66. // commented by GP
  67. #define PSEUDO(name, syscall_name, args) \
  68. lose: \
  69. jmp JUMPTARGET(syscall_error); \
  70. .globl syscall_error; \
  71. ENTRY(name); \
  72. DO_CALL(syscall_name, args); \
  73. jb lose
  74. #undef PSEUDO_END
  75. #define PSEUDO_END(name) END(name)
  76. #undef JUMPTARGET
  77. #ifdef PIC
  78. #define JUMPTARGET(name) name##@PLT
  79. #else
  80. #define JUMPTARGET(name) name
  81. #endif
  82. /* Local label name for asm code. */
  83. #ifndef L
  84. #ifdef HAVE_ELF
  85. /* ELF-like local names start with `.L'. */
  86. #define L(name) .L##name
  87. #else
  88. #define L(name) name
  89. #endif
  90. #endif
  91. #endif /* __ASSEMBLER__ */