gcc/libgcc/config/aarch64/value-unwind.h
Richard Sandiford dbc3af4fc6 SVE unwinding
This patch adds support for unwinding frames that use the SVE
pseudo VG register.  We want this register to act like a normal
register if the CFI explicitly sets it, but want to provide a
default value otherwise.  Computing the default value requires
an SVE target, so we only want to compute it on demand.

aarch64_vg uses a hard-coded .inst in order to avoid a build
dependency on binutils 2.28 or later.

2018-01-13  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	* doc/tm.texi.in (DWARF_LAZY_REGISTER_VALUE): Document.
	* doc/tm.texi: Regenerate.

libgcc/
	* config/aarch64/value-unwind.h (aarch64_vg): New function.
	(DWARF_LAZY_REGISTER_VALUE): Define.
	* unwind-dw2.c (_Unwind_GetGR): Use DWARF_LAZY_REGISTER_VALUE
	to provide a fallback register value.

gcc/testsuite/
	* g++.target/aarch64/sve/aarch64-sve.exp: New harness.
	* g++.target/aarch64/sve/catch_1.C: New test.
	* g++.target/aarch64/sve/catch_2.C: Likewise.
	* g++.target/aarch64/sve/catch_3.C: Likewise.
	* g++.target/aarch64/sve/catch_4.C: Likewise.
	* g++.target/aarch64/sve/catch_5.C: Likewise.
	* g++.target/aarch64/sve/catch_6.C: Likewise.

Reviewed-by: James Greenhalgh <james.greenhalgh@arm.com>

From-SVN: r256615
2018-01-13 17:56:52 +00:00

42 lines
1.6 KiB
C

/* Store register values as _Unwind_Word type in DWARF2 EH unwind context.
Copyright (C) 2017-2018 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published
by the Free Software Foundation; either version 3, or (at your
option) any later version.
GCC is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
License for more details.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
/* Define this macro if the target stores register values as _Unwind_Word
type in unwind context. Only enable it for ilp32. */
#if defined __aarch64__ && !defined __LP64__
# define REG_VALUE_IN_UNWIND_CONTEXT
#endif
/* Return the value of the pseudo VG register. This should only be
called if we know this is an SVE host. */
static inline int
aarch64_vg (void)
{
register int vg asm ("x0");
/* CNTD X0. */
asm (".inst 0x04e0e3e0" : "=r" (vg));
return vg;
}
/* Lazily provide a value for VG, so that we don't try to execute SVE
instructions unless we know they're needed. */
#define DWARF_LAZY_REGISTER_VALUE(REGNO, VALUE) \
((REGNO) == AARCH64_DWARF_VG && ((*VALUE) = aarch64_vg (), 1))