sysdeps/powerpc/powerpc32/sysdep.h

   1 /* Assembly macros for 32-bit PowerPC.
   2    Copyright (C) 1999-2023 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    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <sysdeps/powerpc/sysdep.h>
  20
  21 #ifdef __ASSEMBLER__
  22
  23 /* If compiled for profiling, call `_mcount' at the start of each
  24    function.  */
  25 #ifdef  PROF
  26 /* The mcount code relies on a the return address being on the stack
  27    to locate our caller and so it can restore it; so store one just
  28    for its benefit.  */
  29 # define CALL_MCOUNT                                                          \
  30   mflr  r0;                                                                   \
  31   stw   r0,4(r1);                                                             \
  32   cfi_offset (lr, 4);                                                         \
  33   bl    JUMPTARGET(_mcount);
  34 #else  /* PROF */
  35 # define CALL_MCOUNT            /* Do nothing.  */
  36 #endif /* PROF */
  37
  38 #define ENTRY(name)                                                           \
  39   .globl C_SYMBOL_NAME(name);                                                 \
  40   .type C_SYMBOL_NAME(name),@function;                                        \
  41   .align ALIGNARG(2);                                                         \
  42   C_LABEL(name)                                                               \
  43   cfi_startproc;                                                              \
  44   CALL_MCOUNT
  45
  46 #define ENTRY_TOCLESS(name) ENTRY(name)
  47
  48 /* helper macro for accessing the 32-bit powerpc GOT. */
  49
  50 #define SETUP_GOT_ACCESS(regname,GOT_LABEL)                                   \
  51         bcl     20,31,GOT_LABEL ;                                             \
  52 GOT_LABEL:                      ;                                             \
  53         mflr    (regname)
  54
  55 #define EALIGN_W_0  /* No words to insert.  */
  56 #define EALIGN_W_1  nop
  57 #define EALIGN_W_2  nop;nop
  58 #define EALIGN_W_3  nop;nop;nop
  59 #define EALIGN_W_4  EALIGN_W_3;nop
  60 #define EALIGN_W_5  EALIGN_W_4;nop
  61 #define EALIGN_W_6  EALIGN_W_5;nop
  62 #define EALIGN_W_7  EALIGN_W_6;nop
  63
  64 /* EALIGN is like ENTRY, but does alignment to 'words'*4 bytes
  65    past a 2^align boundary.  */
  66 #ifdef PROF
  67 # define EALIGN(name, alignt, words)                                          \
  68   .globl C_SYMBOL_NAME(name);                                                 \
  69   .type C_SYMBOL_NAME(name),@function;                                        \
  70   .align ALIGNARG(2);                                                         \
  71   C_LABEL(name)                                                               \
  72   cfi_startproc;                                                              \
  73   CALL_MCOUNT                                                                 \
  74   b 0f;                                                                       \
  75   .align ALIGNARG(alignt);                                                    \
  76   EALIGN_W_##words;                                                           \
  77   0:
  78 #else /* PROF */
  79 # define EALIGN(name, alignt, words)                                          \
  80   .globl C_SYMBOL_NAME(name);                                                 \
  81   .type C_SYMBOL_NAME(name),@function;                                        \
  82   .align ALIGNARG(alignt);                                                    \
  83   EALIGN_W_##words;                                                           \
  84   C_LABEL(name)                                                               \
  85   cfi_startproc;
  86 #endif
  87
  88 #undef  END
  89 #define END(name)                                                             \
  90   cfi_endproc;                                                                \
  91   ASM_SIZE_DIRECTIVE(name)
  92
  93 #define DO_CALL(syscall)                                                      \
  94     li 0,syscall;                                                             \
  95     DO_CALL_SC
  96
  97 #define DO_CALL_SC \
  98         sc
  99
 100 #undef JUMPTARGET
 101 #ifdef PIC
 102 # define JUMPTARGET(name) name##@plt
 103 #else
 104 # define JUMPTARGET(name) name
 105 #endif
 106
 107 #if defined SHARED && defined PIC && !defined NO_HIDDEN
 108 # undef HIDDEN_JUMPTARGET
 109 # define HIDDEN_JUMPTARGET(name) __GI_##name##@local
 110 #endif
 111
 112 #define TAIL_CALL_SYSCALL_ERROR \
 113     b __syscall_error@local
 114
 115 #define PSEUDO(name, syscall_name, args)                                      \
 116   .section ".text";                                                           \
 117   ENTRY (name)                                                                \
 118     DO_CALL (SYS_ify (syscall_name));
 119
 120 #define RET_SC \
 121     bnslr+;
 122
 123 #define PSEUDO_RET                                                            \
 124     RET_SC;                                                                   \
 125     TAIL_CALL_SYSCALL_ERROR
 126 #define ret PSEUDO_RET
 127
 128 #undef  PSEUDO_END
 129 #define PSEUDO_END(name)                                                      \
 130   END (name)
 131
 132 #define PSEUDO_NOERRNO(name, syscall_name, args)                              \
 133   .section ".text";                                                           \
 134   ENTRY (name)                                                                \
 135     DO_CALL (SYS_ify (syscall_name));
 136
 137 #define PSEUDO_RET_NOERRNO                                                    \
 138     blr
 139 #define ret_NOERRNO PSEUDO_RET_NOERRNO
 140
 141 #undef  PSEUDO_END_NOERRNO
 142 #define PSEUDO_END_NOERRNO(name)                                              \
 143   END (name)
 144
 145 #define PSEUDO_ERRVAL(name, syscall_name, args)                               \
 146   .section ".text";                                                           \
 147   ENTRY (name)                                                                \
 148     DO_CALL (SYS_ify (syscall_name));
 149
 150 #define PSEUDO_RET_ERRVAL                                                     \
 151     blr
 152 #define ret_ERRVAL PSEUDO_RET_ERRVAL
 153
 154 #undef  PSEUDO_END_ERRVAL
 155 #define PSEUDO_END_ERRVAL(name)                                               \
 156   END (name)
 157
 158 /* Local labels stripped out by the linker.  */
 159 #undef L
 160 #define L(x) .L##x
 161
 162 #define XGLUE(a,b) a##b
 163 #define GLUE(a,b) XGLUE (a,b)
 164 #define GENERATE_GOT_LABEL(name) GLUE (.got_label, name)
 165
 166 /* Label in text section.  */
 167 #define C_TEXT(name) name
 168
 169 /* Read the value of member from rtld_global_ro.  */
 170 #ifdef PIC
 171 # ifdef SHARED
 172 #  if IS_IN (rtld)
 173 /* Inside ld.so we use the local alias to avoid runtime GOT
 174    relocations.  */
 175 #   define __GLRO(rOUT, rGOT, member, offset)                           \
 176         lwz     rOUT,_rtld_local_ro@got(rGOT);                          \
 177         lwz     rOUT,offset(rOUT)
 178 #  else
 179 #   define __GLRO(rOUT, rGOT, member, offset)                           \
 180         lwz     rOUT,_rtld_global_ro@got(rGOT);                         \
 181         lwz     rOUT,offset(rOUT)
 182 #  endif
 183 # else
 184 #  define __GLRO(rOUT, rGOT, member, offset)                            \
 185         lwz     rOUT,member@got(rGOT);                                  \
 186         lwz     rOUT,0(rOUT)
 187 # endif
 188 #else
 189 /* Position-dependent code does not require access to the GOT.  */
 190 # define __GLRO(rOUT, rGOT, member, offset)                             \
 191         lis     rOUT,(member)@ha;                                       \
 192         lwz     rOUT,(member)@l(rOUT)
 193 #endif  /* PIC */
 194
 195 #endif  /* __ASSEMBLER__ */