libgcc/config/aarch64/aarch64-asm.h

   1 /* AArch64 asm definitions.
   2    Copyright (C) 2023-2024 Free Software Foundation, Inc.
   3
   4    This file is part of GCC.
   5
   6    GCC is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published
   8    by the Free Software Foundation; either version 3, or (at your
   9    option) any later version.
  10
  11    GCC is distributed in the hope that it will be useful, but WITHOUT
  12    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  14    License for more details.
  15
  16    Under Section 7 of GPL version 3, you are granted additional
  17    permissions described in the GCC Runtime Library Exception, version
  18    3.1, as published by the Free Software Foundation.
  19
  20    You should have received a copy of the GNU General Public License and
  21    a copy of the GCC Runtime Library Exception along with this program;
  22    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23    <http://www.gnu.org/licenses/>.  */
  24
  25 #include "auto-target.h"
  26
  27 #define L(label) .L ## label
  28
  29 /* Marking variant PCS symbol references is important for PLT calls
  30    otherwise it is for documenting the PCS in the symbol table.  */
  31 #ifdef HAVE_AS_VARIANT_PCS
  32 # define variant_pcs(name) .variant_pcs name
  33 #else
  34 # define variant_pcs(name)
  35 #endif
  36
  37 /* GNU_PROPERTY_AARCH64_* macros from elf.h for use in asm code.  */
  38 #define FEATURE_1_AND 0xc0000000
  39 #define FEATURE_1_BTI 1
  40 #define FEATURE_1_PAC 2
  41
  42 /* Supported features based on the code generation options.  */
  43 #if defined(__ARM_FEATURE_BTI_DEFAULT)
  44 # define BTI_FLAG FEATURE_1_BTI
  45 # define BTI_C hint     34
  46 #else
  47 # define BTI_FLAG 0
  48 # define BTI_C
  49 #endif
  50
  51 #if __ARM_FEATURE_PAC_DEFAULT & 3
  52 # define PAC_FLAG FEATURE_1_PAC
  53 # define PACIASP hint   25; .cfi_window_save
  54 # define AUTIASP hint   29; .cfi_window_save
  55 #else
  56 # define PAC_FLAG 0
  57 # define PACIASP
  58 # define AUTIASP
  59 #endif
  60
  61 /* Add a NT_GNU_PROPERTY_TYPE_0 note.  */
  62 #define GNU_PROPERTY(type, value)       \
  63   .section .note.gnu.property, "a";     \
  64   .p2align 3;                           \
  65   .word 4;                              \
  66   .word 16;                             \
  67   .word 5;                              \
  68   .asciz "GNU";                         \
  69   .word type;                           \
  70   .word 4;                              \
  71   .word value;                          \
  72   .word 0;                              \
  73   .previous
  74
  75 #if defined(__linux__) || defined(__FreeBSD__)
  76 /* Do not require executable stack.  */
  77 .section .note.GNU-stack, "", %progbits
  78 .previous
  79
  80 /* Add GNU property note if built with branch protection.  */
  81 # if (BTI_FLAG|PAC_FLAG) != 0
  82 GNU_PROPERTY (FEATURE_1_AND, BTI_FLAG|PAC_FLAG)
  83 # endif
  84 #endif
  85
  86 #define ENTRY_ALIGN(name, align) \
  87   .global name;         \
  88   .type name,%function; \
  89   .balign align;        \
  90   name:                 \
  91   .cfi_startproc;       \
  92   BTI_C
  93
  94 #define ENTRY(name) ENTRY_ALIGN(name, 16)
  95
  96 #define END(name) \
  97   .cfi_endproc;         \
  98   .size name, .-name