gcc/config/arm/elf.h

   1 /* Definitions of target machine for GNU compiler.
   2    For ARM with ELF obj format.
   3    Copyright (C) 1995-2024 Free Software Foundation, Inc.
   4    Contributed by Philip Blundell <philb@gnu.org> and
   5    Catherine Moore <clm@cygnus.com>
   6
   7    This file is part of GCC.
   8
   9    GCC is free software; you can redistribute it and/or modify it
  10    under the terms of the GNU General Public License as published
  11    by the Free Software Foundation; either version 3, or (at your
  12    option) any later version.
  13
  14    GCC is distributed in the hope that it will be useful, but WITHOUT
  15    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  16    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  17    License for more details.
  18
  19    Under Section 7 of GPL version 3, you are granted additional
  20    permissions described in the GCC Runtime Library Exception, version
  21    3.1, as published by the Free Software Foundation.
  22
  23    You should have received a copy of the GNU General Public License and
  24    a copy of the GCC Runtime Library Exception along with this program;
  25    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  26    <http://www.gnu.org/licenses/>.  */
  27
  28 #ifndef OBJECT_FORMAT_ELF
  29  #error elf.h included before elfos.h
  30 #endif
  31
  32 #ifndef LOCAL_LABEL_PREFIX
  33 #define LOCAL_LABEL_PREFIX "."
  34 #endif
  35
  36 #ifndef SUBTARGET_CPP_SPEC
  37 #define SUBTARGET_CPP_SPEC  "-D__ELF__"
  38 #endif
  39
  40 #ifndef SUBTARGET_EXTRA_SPECS
  41 #define SUBTARGET_EXTRA_SPECS \
  42   { "subtarget_extra_asm_spec", SUBTARGET_EXTRA_ASM_SPEC }, \
  43   { "subtarget_asm_float_spec", SUBTARGET_ASM_FLOAT_SPEC }, \
  44   SUBSUBTARGET_EXTRA_SPECS
  45 #endif
  46
  47 #ifndef SUBTARGET_EXTRA_ASM_SPEC
  48 #define SUBTARGET_EXTRA_ASM_SPEC ""
  49 #endif
  50
  51 #ifndef SUBTARGET_ASM_FLOAT_SPEC
  52 #define SUBTARGET_ASM_FLOAT_SPEC "\
  53 %{mapcs-float:-mfloat}"
  54 #endif
  55
  56 #undef SUBSUBTARGET_EXTRA_SPECS
  57 #define SUBSUBTARGET_EXTRA_SPECS
  58
  59 #ifndef ASM_SPEC
  60 #define ASM_SPEC "\
  61 %{mbig-endian:-EB} \
  62 %{mlittle-endian:-EL} \
  63 %(asm_cpu_spec) \
  64 %{mapcs-*:-mapcs-%*} \
  65 %(subtarget_asm_float_spec) \
  66 %{mthumb-interwork:-mthumb-interwork} \
  67 %{mfloat-abi=*} %{!mfpu=auto: %{mfpu=*}} \
  68 %(subtarget_extra_asm_spec)"
  69 #endif
  70
  71 /* The ARM uses @ are a comment character so we need to redefine
  72    TYPE_OPERAND_FMT.  */
  73 #undef  TYPE_OPERAND_FMT
  74 #define TYPE_OPERAND_FMT        "%%%s"
  75
  76 /* We might need a ARM specific header to function declarations.  */
  77 #undef  ASM_DECLARE_FUNCTION_NAME
  78 #define ASM_DECLARE_FUNCTION_NAME arm_asm_declare_function_name
  79
  80 /* We might need an ARM specific trailer for function declarations.  */
  81 #undef  ASM_DECLARE_FUNCTION_SIZE
  82 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL)            \
  83   do                                                            \
  84     {                                                           \
  85       ARM_OUTPUT_FN_UNWIND (FILE, FALSE);                       \
  86       if (!flag_inhibit_size_directive)                         \
  87         ASM_OUTPUT_MEASURED_SIZE (FILE, FNAME);                 \
  88     }                                                           \
  89   while (0)
  90
  91 /* Define this macro if jump tables (for `tablejump' insns) should be
  92    output in the text section, along with the assembler instructions.
  93    Otherwise, the readonly data section is used.  */
  94 /* The choice of placement for jump tables is nuanced.  For cores with
  95    Harvard caches (pretty much all cases these days), there is a
  96    benefit of maintaing a separation between I- and D-cache candidates
  97    and that favors having jump tables in the RO data section.  This
  98    makes the dispatch sequence slightly longer as we need to load the
  99    address of the jump table first, but we often save elsewhere as the
 100    content of the code section becomes better packed and we need
 101    fewer long-range branch operations.  We also require the dispatch
 102    table to be in the RO section when compiling for pure code.  We
 103    currently place jump tables in the RO-data section for Arm or
 104    whenever pure code is required; we also do it for Thumb-1 when
 105    using an ADDR_VEC.  The remaining cases put the jump table in the
 106    text section, but we should revisit this choice.  */
 107 #define JUMP_TABLES_IN_TEXT_SECTION                                     \
 108    ((TARGET_THUMB2 || (TARGET_THUMB && (optimize_size || flag_pic))) \
 109     && !target_pure_code)
 110
 111 #ifndef LINK_SPEC
 112 #define LINK_SPEC "%{mbig-endian:-EB} %{mlittle-endian:-EL} -X"
 113 #endif
 114
 115 /* Run-time Target Specification.  */
 116 #ifndef TARGET_DEFAULT
 117 #define TARGET_DEFAULT (MASK_APCS_FRAME)
 118 #endif
 119
 120 \f
 121 #define TARGET_ASM_FILE_START_FILE_DIRECTIVE true
 122 \f
 123
 124 /* Output an element in the static constructor array.  */
 125 #undef TARGET_ASM_CONSTRUCTOR
 126 #define TARGET_ASM_CONSTRUCTOR arm_elf_asm_constructor
 127
 128 #undef TARGET_ASM_DESTRUCTOR
 129 #define TARGET_ASM_DESTRUCTOR arm_elf_asm_destructor
 130
 131 /* For PIC code we need to explicitly specify (PLT) and (GOT) relocs.  */
 132 #define NEED_PLT_RELOC  flag_pic
 133 #define NEED_GOT_RELOC  flag_pic
 134
 135 /* The ELF assembler handles GOT addressing differently to NetBSD.  */
 136 #define GOT_PCREL       0
 137
 138 /* Align output to a power of two.  Note ".align 0" is redundant,
 139    and also GAS will treat it as ".align 2" which we do not want.  */
 140 #define ASM_OUTPUT_ALIGN(STREAM, POWER)                 \
 141   do                                                    \
 142     {                                                   \
 143       if ((POWER) > 0)                                  \
 144         fprintf (STREAM, "\t.align\t%d\n", POWER);      \
 145     }                                                   \
 146   while (0)
 147
 148 /* Horrible hack: We want to prevent some libgcc routines being included
 149    for some multilibs.  The condition should match the one in
 150    libgcc/config/arm/lib1funcs.S and libgcc/config/arm/t-elf.  */
 151 #if __ARM_ARCH_ISA_ARM || __ARM_ARCH_ISA_THUMB != 1
 152 #undef L_fixdfsi
 153 #undef L_fixunsdfsi
 154 #undef L_truncdfsf2
 155 #undef L_fixsfsi
 156 #undef L_fixunssfsi
 157 #undef L_floatdidf
 158 #undef L_floatdisf
 159 #undef L_floatundidf
 160 #undef L_floatundisf
 161 #endif
 162