sysdeps/unix/sysv/linux/powerpc/sysdep.h

   1 /* Copyright (C) 1992, 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <sysdeps/unix/sysdep.h>
  20
  21 /* For Linux we can use the system call table in the header file
  22         /usr/include/asm/unistd.h
  23    of the kernel.  But these symbols do not follow the SYS_* syntax
  24    so we have to redefine the `SYS_ify' macro here.  */
  25 #undef SYS_ify
  26 #ifdef __STDC__
  27 # define SYS_ify(syscall_name)  __NR_##syscall_name
  28 #else
  29 # define SYS_ify(syscall_name)  __NR_/**/syscall_name
  30 #endif
  31
  32 #ifdef ASSEMBLER
  33
  34 /* This seems to always be the case on PPC.  */
  35 #define ALIGNARG(log2) log2
  36 /* For ELF we need the `.type' directive to make shared libs work right.  */
  37 #define ASM_TYPE_DIRECTIVE(name,typearg) .type name,typearg;
  38 #define ASM_SIZE_DIRECTIVE(name) .size name,.-name
  39
  40 /* If compiled for profiling, call `_mcount' at the start of each function.  */
  41 #ifdef  PROF
  42 /* The mcount code relies on a the return address being on the stack
  43    to locate our caller and so it can restore it; so store one just
  44    for its benefit.  */
  45 #ifdef PIC
  46 #define CALL_MCOUNT                                                           \
  47   .pushsection;                                                               \
  48   .section ".data";                                                           \
  49   .align ALIGNARG(2);                                                         \
  50 0:.long 0;                                                                    \
  51   .previous;                                                                  \
  52   mflr  %r0;                                                                  \
  53   stw   %r0,4(%r1);                                                           \
  54   bl    _GLOBAL_OFFSET_TABLE_@local-4;                                        \
  55   mflr  %r11;                                                                 \
  56   lwz   %r0,0b@got(%r11);                                                     \
  57   bl    JUMPTARGET(_mcount);
  58 #else  /* PIC */
  59 #define CALL_MCOUNT                                                           \
  60   .section ".data";                                                           \
  61   .align ALIGNARG(2);                                                         \
  62 0:.long 0;                                                                    \
  63   .previous;                                                                  \
  64   mflr  %r0;                                                                  \
  65   lis   %r11,0b@ha;                                                           \
  66   stw   %r0,4(%r1);                                                           \
  67   addi  %r0,%r11,0b@l;                                                        \
  68   bl    JUMPTARGET(_mcount);
  69 #endif /* PIC */
  70 #else  /* PROF */
  71 #define CALL_MCOUNT             /* Do nothing.  */
  72 #endif /* PROF */
  73
  74 #define ENTRY(name)                                                           \
  75   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name);                                   \
  76   ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),@function)                          \
  77   .align ALIGNARG(2);                                                         \
  78   C_LABEL(name)                                                               \
  79   CALL_MCOUNT
  80
  81 #define EALIGN_W_0  /* No words to insert.  */
  82 #define EALIGN_W_1  nop
  83 #define EALIGN_W_2  nop;nop
  84 #define EALIGN_W_3  nop;nop;nop
  85 #define EALIGN_W_4  EALIGN_W_3;nop
  86 #define EALIGN_W_5  EALIGN_W_4;nop
  87 #define EALIGN_W_6  EALIGN_W_5;nop
  88 #define EALIGN_W_7  EALIGN_W_6;nop
  89
  90 /* EALIGN is like ENTRY, but does alignment to 'words'*4 bytes
  91    past a 2^align boundary.  */
  92 #ifdef PROF
  93 #define EALIGN(name, alignt, words)                                           \
  94   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name);                                   \
  95   ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),@function)                          \
  96   .align ALIGNARG(2);                                                         \
  97   C_LABEL(name)                                                               \
  98   CALL_MCOUNT                                                                 \
  99   b 0f;                                                                       \
 100   .align ALIGNARG(alignt);                                                    \
 101   EALIGN_W_##words;                                                           \
 102   0:
 103 #else /* PROF */
 104 #define EALIGN(name, alignt, words)                                           \
 105   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name);                                   \
 106   ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),@function)                          \
 107   .align ALIGNARG(alignt);                                                    \
 108   EALIGN_W_##words;                                                           \
 109   C_LABEL(name)
 110 #endif
 111
 112 #undef  END
 113 #define END(name)                                                             \
 114   ASM_SIZE_DIRECTIVE(name)
 115
 116 #define DO_CALL(syscall)                                                      \
 117     li 0,syscall;                                                             \
 118     sc
 119
 120 #ifdef PIC
 121 #define JUMPTARGET(name) name##@plt
 122 #else
 123 #define JUMPTARGET(name) name
 124 #endif
 125
 126 #define PSEUDO(name, syscall_name, args)                                      \
 127   .section ".text";                                                           \
 128   ENTRY (name)                                                                \
 129     DO_CALL (SYS_ify (syscall_name));
 130
 131 #define PSEUDO_RET                                                            \
 132     bnslr;                                                                    \
 133     b JUMPTARGET(__syscall_error)
 134 #define ret PSEUDO_RET
 135
 136 #undef  PSEUDO_END
 137 #define PSEUDO_END(name)                                                      \
 138   END (name)
 139
 140 /* Local labels stripped out by the linker.  */
 141 #define L(x) .L##x
 142
 143 #endif  /* ASSEMBLER */