Complete rewrite.
[kopensolaris-gnu/glibc.git] / 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__ */