sysdeps/x86_64/sysdep.h

   1 /* Assembler macros for x86-64.
   2    Copyright (C) 2001-2017 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _X86_64_SYSDEP_H
  20 #define _X86_64_SYSDEP_H 1
  21
  22 #include <sysdeps/generic/sysdep.h>
  23
  24 #ifdef  __ASSEMBLER__
  25
  26 /* Syntactic details of assembler.  */
  27
  28 /* This macro is for setting proper CFI with DW_CFA_expression describing
  29    the register as saved relative to %rsp instead of relative to the CFA.
  30    Expression is DW_OP_drop, DW_OP_breg7 (%rsp is register 7), sleb128 offset
  31    from %rsp.  */
  32 #define cfi_offset_rel_rsp(regn, off)   .cfi_escape 0x10, regn, 0x4, 0x13, \
  33                                         0x77, off & 0x7F | 0x80, off >> 7
  34
  35 /* ELF uses byte-counts for .align, most others use log2 of count of bytes.  */
  36 #define ALIGNARG(log2) 1<<log2
  37 #define ASM_SIZE_DIRECTIVE(name) .size name,.-name;
  38
  39
  40 /* Define an entry point visible from C.  */
  41 #define ENTRY(name)                                                           \
  42   .globl C_SYMBOL_NAME(name);                                                 \
  43   .type C_SYMBOL_NAME(name),@function;                                        \
  44   .align ALIGNARG(4);                                                         \
  45   C_LABEL(name)                                                               \
  46   cfi_startproc;                                                              \
  47   CALL_MCOUNT
  48
  49 #undef  END
  50 #define END(name)                                                             \
  51   cfi_endproc;                                                                \
  52   ASM_SIZE_DIRECTIVE(name)
  53
  54 #define ENTRY_CHK(name) ENTRY (name)
  55 #define END_CHK(name) END (name)
  56
  57 /* If compiled for profiling, call `mcount' at the start of each function.  */
  58 #ifdef  PROF
  59 /* The mcount code relies on a normal frame pointer being on the stack
  60    to locate our caller, so push one just for its benefit.  */
  61 #define CALL_MCOUNT                                                          \
  62   pushq %rbp;                                                                \
  63   cfi_adjust_cfa_offset(8);                                                  \
  64   movq %rsp, %rbp;                                                           \
  65   cfi_def_cfa_register(%rbp);                                                \
  66   call JUMPTARGET(mcount);                                                   \
  67   popq %rbp;                                                                 \
  68   cfi_def_cfa(rsp,8);
  69 #else
  70 #define CALL_MCOUNT             /* Do nothing.  */
  71 #endif
  72
  73 /* Since C identifiers are not normally prefixed with an underscore
  74    on this system, the asm identifier `syscall_error' intrudes on the
  75    C name space.  Make sure we use an innocuous name.  */
  76 #define syscall_error   __syscall_error
  77 #define mcount          _mcount
  78
  79 #define PSEUDO(name, syscall_name, args)                                      \
  80 lose:                                                                         \
  81   jmp JUMPTARGET(syscall_error)                                               \
  82   .globl syscall_error;                                                       \
  83   ENTRY (name)                                                                \
  84   DO_CALL (syscall_name, args);                                               \
  85   jb lose
  86
  87 #undef  PSEUDO_END
  88 #define PSEUDO_END(name)                                                      \
  89   END (name)
  90
  91 #undef JUMPTARGET
  92 #ifdef SHARED
  93 # ifdef BIND_NOW
  94 #  define JUMPTARGET(name)      *name##@GOTPCREL(%rip)
  95 # else
  96 #  define JUMPTARGET(name)      name##@PLT
  97 # endif
  98 #else
  99 /* For static archives, branch to target directly.  */
 100 # define JUMPTARGET(name)       name
 101 #endif
 102
 103 /* Local label name for asm code. */
 104 #ifndef L
 105 /* ELF-like local names start with `.L'.  */
 106 # define L(name)        .L##name
 107 #endif
 108
 109 #define atom_text_section .section ".text.atom", "ax"
 110
 111 /* Long and pointer size in bytes.  */
 112 #define LP_SIZE 8
 113
 114 /* Instruction to operate on long and pointer.  */
 115 #define LP_OP(insn) insn##q
 116
 117 /* Assembler address directive. */
 118 #define ASM_ADDR .quad
 119
 120 /* Registers to hold long and pointer.  */
 121 #define RAX_LP  rax
 122 #define RBP_LP  rbp
 123 #define RBX_LP  rbx
 124 #define RCX_LP  rcx
 125 #define RDI_LP  rdi
 126 #define RDX_LP  rdx
 127 #define RSI_LP  rsi
 128 #define RSP_LP  rsp
 129 #define R8_LP   r8
 130 #define R9_LP   r9
 131 #define R10_LP  r10
 132 #define R11_LP  r11
 133 #define R12_LP  r12
 134 #define R13_LP  r13
 135 #define R14_LP  r14
 136 #define R15_LP  r15
 137
 138 #else   /* __ASSEMBLER__ */
 139
 140 /* Long and pointer size in bytes.  */
 141 #define LP_SIZE "8"
 142
 143 /* Instruction to operate on long and pointer.  */
 144 #define LP_OP(insn) #insn "q"
 145
 146 /* Assembler address directive. */
 147 #define ASM_ADDR ".quad"
 148
 149 /* Registers to hold long and pointer.  */
 150 #define RAX_LP  "rax"
 151 #define RBP_LP  "rbp"
 152 #define RBX_LP  "rbx"
 153 #define RCX_LP  "rcx"
 154 #define RDI_LP  "rdi"
 155 #define RDX_LP  "rdx"
 156 #define RSI_LP  "rsi"
 157 #define RSP_LP  "rsp"
 158 #define R8_LP   "r8"
 159 #define R9_LP   "r9"
 160 #define R10_LP  "r10"
 161 #define R11_LP  "r11"
 162 #define R12_LP  "r12"
 163 #define R13_LP  "r13"
 164 #define R14_LP  "r14"
 165 #define R15_LP  "r15"
 166
 167 #endif  /* __ASSEMBLER__ */
 168
 169 #endif  /* _X86_64_SYSDEP_H */