ports/sysdeps/arm/sysdep.h

   1 /* Assembler macros for ARM.
   2    Copyright (C) 1997, 1998, 2003, 2009, 2010, 2012
   3    Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library.  If not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <sysdeps/generic/sysdep.h>
  21 #include <features.h>
  22
  23 #if (!defined (__ARM_ARCH_2__) && !defined (__ARM_ARCH_3__) \
  24      && !defined (__ARM_ARCH_3M__) && !defined (__ARM_ARCH_4__))
  25 # define __USE_BX__
  26 #endif
  27
  28 #ifdef  __ASSEMBLER__
  29
  30 /* Syntactic details of assembler.  */
  31
  32 #define ALIGNARG(log2) log2
  33 /* For ELF we need the `.type' directive to make shared libs work right.  */
  34 #define ASM_TYPE_DIRECTIVE(name,typearg) .type name,%##typearg;
  35 #define ASM_SIZE_DIRECTIVE(name) .size name,.-name
  36
  37 #define PLTJMP(_x)      _x##(PLT)
  38
  39 /* APCS-32 doesn't preserve the condition codes across function call. */
  40 #ifdef __APCS_32__
  41 #define LOADREGS(cond, base, reglist...)\
  42         ldm##cond       base,reglist
  43 #ifdef __USE_BX__
  44 #define RETINSTR(cond, reg)     \
  45         bx##cond        reg
  46 #define DO_RET(_reg)            \
  47         bx _reg
  48 #else
  49 #define RETINSTR(cond, reg)     \
  50         mov##cond       pc, reg
  51 #define DO_RET(_reg)            \
  52         mov pc, _reg
  53 #endif
  54 #else  /* APCS-26 */
  55 #define LOADREGS(cond, base, reglist...)\
  56         ldm##cond       base,reglist^
  57 #define RETINSTR(cond, reg)     \
  58         mov##cond##s    pc, reg
  59 #define DO_RET(_reg)            \
  60         movs pc, _reg
  61 #endif
  62
  63 /* Define an entry point visible from C.  */
  64 #define ENTRY(name)                                                           \
  65   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name);                                   \
  66   ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),function)                           \
  67   .align ALIGNARG(4);                                                         \
  68   C_LABEL(name)                                                               \
  69   .cfi_sections .debug_frame;                                                 \
  70   cfi_startproc;                                                              \
  71   CALL_MCOUNT
  72
  73 #undef  END
  74 #define END(name)                                                             \
  75   cfi_endproc;                                                                \
  76   ASM_SIZE_DIRECTIVE(name)
  77
  78 /* If compiled for profiling, call `mcount' at the start of each function.  */
  79 #ifdef  PROF
  80 /* Call __gnu_mcount_nc if GCC >= 4.4.  */
  81 #if __GNUC_PREREQ(4,4)
  82 #define CALL_MCOUNT \
  83   str   lr,[sp, #-4]!; \
  84   cfi_adjust_cfa_offset (4); \
  85   cfi_rel_offset (lr, 0); \
  86   bl PLTJMP(mcount); \
  87   cfi_adjust_cfa_offset (-4); \
  88   cfi_restore (lr)
  89 #else /* else call _mcount */
  90 #define CALL_MCOUNT \
  91   str   lr,[sp, #-4]!; \
  92   cfi_adjust_cfa_offset (4); \
  93   cfi_rel_offset (lr, 0); \
  94   bl PLTJMP(mcount); \
  95   ldr lr, [sp], #4; \
  96   cfi_adjust_cfa_offset (-4); \
  97   cfi_restore (lr)
  98 #endif
  99 #else
 100 #define CALL_MCOUNT             /* Do nothing.  */
 101 #endif
 102
 103 /* Since C identifiers are not normally prefixed with an underscore
 104    on this system, the asm identifier `syscall_error' intrudes on the
 105    C name space.  Make sure we use an innocuous name.  */
 106 #define syscall_error   __syscall_error
 107 #if __GNUC_PREREQ(4,4)
 108 #define mcount          __gnu_mcount_nc
 109 #else
 110 #define mcount          _mcount
 111 #endif
 112
 113 /* Tag_ABI_align8_preserved: This code preserves 8-byte
 114    alignment in any callee.  */
 115         .eabi_attribute 25, 1
 116 /* Tag_ABI_align8_needed: This code may require 8-byte alignment from
 117    the caller.  */
 118         .eabi_attribute 24, 1
 119
 120 #endif  /* __ASSEMBLER__ */