xref: /netbsd-src/external/gpl3/gcc/dist/libgcc/config/aarch64/value-unwind.h (revision e6c7e151de239c49d2e38720a061ed9d1fa99309)
1 /* Store register values as _Unwind_Word type in DWARF2 EH unwind context.
2    Copyright (C) 2017-2018 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))
42