libgcc/config/aarch64/value-unwind.h

   1 /* Store register values as _Unwind_Word type in DWARF2 EH unwind context.
   2    Copyright (C) 2017-2020 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    You should have received a copy of the GNU General Public License and
  17    a copy of the GCC Runtime Library Exception along with this program;
  18    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  19    <http://www.gnu.org/licenses/>.  */
  20
  21 /* Define this macro if the target stores register values as _Unwind_Word
  22    type in unwind context.  Only enable it for ilp32.  */
  23 #if defined __aarch64__ && !defined __LP64__
  24 # define REG_VALUE_IN_UNWIND_CONTEXT
  25 #endif
  26
  27 /* Return the value of the pseudo VG register.  This should only be
  28    called if we know this is an SVE host.  */
  29 static inline int
  30 aarch64_vg (void)
  31 {
  32   register int vg asm ("x0");
  33   /* CNTD X0.  */
  34   asm (".inst 0x04e0e3e0" : "=r" (vg));
  35   return vg;
  36 }
  37
  38 /* Lazily provide a value for VG, so that we don't try to execute SVE
  39    instructions unless we know they're needed.  */
  40 #define DWARF_LAZY_REGISTER_VALUE(REGNO, VALUE) \
  41   ((REGNO) == AARCH64_DWARF_VG && ((*VALUE) = aarch64_vg (), 1))