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
This commit is contained in:
Richard Sandiford 2018-01-13 17:56:52 +00:00 committed by Richard Sandiford
parent 825b856cd0
commit dbc3af4fc6
14 changed files with 349 additions and 4 deletions

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@ -1,3 +1,8 @@
2018-01-13 Richard Sandiford <richard.sandiford@linaro.org>
* doc/tm.texi.in (DWARF_LAZY_REGISTER_VALUE): Document.
* doc/tm.texi: Regenerate.
2018-01-13 Richard Sandiford <richard.sandiford@linaro.org>
Alan Hayward <alan.hayward@arm.com>
David Sherwood <david.sherwood@arm.com>

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@ -3621,6 +3621,13 @@ defined and 0 otherwise.
@end defmac
@defmac DWARF_LAZY_REGISTER_VALUE (@var{regno}, @var{value})
Define this macro if the target has pseudo DWARF registers whose
values need to be computed lazily on demand by the unwinder (such as when
referenced in a CFA expression). The macro returns true if @var{regno}
is such a register and stores its value in @samp{*@var{value}} if so.
@end defmac
@node Elimination
@subsection Eliminating Frame Pointer and Arg Pointer

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@ -3002,6 +3002,13 @@ defined and 0 otherwise.
@end defmac
@defmac DWARF_LAZY_REGISTER_VALUE (@var{regno}, @var{value})
Define this macro if the target has pseudo DWARF registers whose
values need to be computed lazily on demand by the unwinder (such as when
referenced in a CFA expression). The macro returns true if @var{regno}
is such a register and stores its value in @samp{*@var{value}} if so.
@end defmac
@node Elimination
@subsection Eliminating Frame Pointer and Arg Pointer

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@ -1,3 +1,13 @@
2018-01-13 Richard Sandiford <richard.sandiford@linaro.org>
* 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.
2018-01-13 Richard Sandiford <richard.sandiford@linaro.org>
Alan Hayward <alan.hayward@arm.com>
David Sherwood <david.sherwood@arm.com>

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@ -0,0 +1,45 @@
# Specific regression driver for AArch64.
# Copyright (C) 2009-2017 Free Software Foundation, Inc.
# Contributed by ARM Ltd.
#
# 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
# along with GCC; see the file COPYING3. If not see
# <http://www.gnu.org/licenses/>. */
# GCC testsuite that uses the `dg.exp' driver.
# Exit immediately if this isn't an AArch64 target.
if {![istarget aarch64*-*-*] } then {
return
}
# Load support procs.
load_lib g++-dg.exp
# Initialize `dg'.
dg-init
# Force SVE if we're not testing it already.
if { [check_effective_target_aarch64_sve] } {
set sve_flags ""
} else {
set sve_flags "-march=armv8.2-a+sve"
}
# Main loop.
dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.C]] $sve_flags ""
# All done.
dg-finish

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@ -0,0 +1,69 @@
/* { dg-do run { target aarch64_sve_hw } } */
/* { dg-options "-O3 -fopenmp-simd -fno-omit-frame-pointer" } */
/* Invoke X (P##n) for n in [0, 7]. */
#define REPEAT8(X, P) \
X (P##0) X (P##1) X (P##2) X (P##3) X (P##4) X (P##5) X (P##6) X (P##7)
/* Invoke X (n) for all octal n in [0, 39]. */
#define REPEAT40(X) \
REPEAT8 (X, 0) REPEAT8 (X, 1) REPEAT8 (X, 2) REPEAT8 (X, 3) REPEAT8 (X, 4)
volatile int testi;
/* Throw to f3. */
void __attribute__ ((weak))
f1 (int x[40][100], int *y)
{
/* A wild write to x and y. */
asm volatile ("" ::: "memory");
if (y[testi] == x[testi][testi])
throw 100;
}
/* Expect vector work to be done, with spilling of vector registers. */
void __attribute__ ((weak))
f2 (int x[40][100], int *y)
{
/* Try to force some spilling. */
#define DECLARE(N) int y##N = y[N];
REPEAT40 (DECLARE);
for (int j = 0; j < 20; ++j)
{
f1 (x, y);
#pragma omp simd
for (int i = 0; i < 100; ++i)
{
#define INC(N) x[N][i] += y##N;
REPEAT40 (INC);
}
}
}
/* Catch an exception thrown from f1, via f2. */
void __attribute__ ((weak))
f3 (int x[40][100], int *y, int *z)
{
volatile int extra = 111;
try
{
f2 (x, y);
}
catch (int val)
{
*z = val + extra;
}
}
static int x[40][100];
static int y[40];
static int z;
int
main (void)
{
f3 (x, y, &z);
if (z != 211)
__builtin_abort ();
return 0;
}

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@ -0,0 +1,4 @@
/* { dg-do run { target aarch64_sve_hw } } */
/* { dg-options "-O3 -fopenmp-simd -fomit-frame-pointer" } */
#include "catch_1.C"

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@ -0,0 +1,78 @@
/* { dg-do run { target aarch64_sve_hw } } */
/* { dg-options "-O3 -fopenmp-simd -fno-omit-frame-pointer" } */
/* Invoke X (P##n) for n in [0, 7]. */
#define REPEAT8(X, P) \
X (P##0) X (P##1) X (P##2) X (P##3) X (P##4) X (P##5) X (P##6) X (P##7)
/* Invoke X (n) for all octal n in [0, 39]. */
#define REPEAT40(X) \
REPEAT8 (X, 0) REPEAT8 (X, 1) REPEAT8 (X, 2) REPEAT8 (X, 3) REPEAT8 (X, 4)
volatile int testi, sink;
/* Take 2 stack arguments and throw to f3. */
void __attribute__ ((weak))
f1 (int x[40][100], int *y, int z1, int z2, int z3, int z4,
int z5, int z6, int z7, int z8)
{
/* A wild write to x and y. */
sink = z1;
sink = z2;
sink = z3;
sink = z4;
sink = z5;
sink = z6;
sink = z7;
sink = z8;
asm volatile ("" ::: "memory");
if (y[testi] == x[testi][testi])
throw 100;
}
/* Expect vector work to be done, with spilling of vector registers. */
void __attribute__ ((weak))
f2 (int x[40][100], int *y)
{
/* Try to force some spilling. */
#define DECLARE(N) int y##N = y[N];
REPEAT40 (DECLARE);
for (int j = 0; j < 20; ++j)
{
f1 (x, y, 1, 2, 3, 4, 5, 6, 7, 8);
#pragma omp simd
for (int i = 0; i < 100; ++i)
{
#define INC(N) x[N][i] += y##N;
REPEAT40 (INC);
}
}
}
/* Catch an exception thrown from f1, via f2. */
void __attribute__ ((weak))
f3 (int x[40][100], int *y, int *z)
{
volatile int extra = 111;
try
{
f2 (x, y);
}
catch (int val)
{
*z = val + extra;
}
}
static int x[40][100];
static int y[40];
static int z;
int
main (void)
{
f3 (x, y, &z);
if (z != 211)
__builtin_abort ();
return 0;
}

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@ -0,0 +1,4 @@
/* { dg-do run { target aarch64_sve_hw } } */
/* { dg-options "-O3 -fopenmp-simd -fomit-frame-pointer" } */
#include "catch_3.C"

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@ -0,0 +1,81 @@
/* { dg-do run { target aarch64_sve_hw } } */
/* { dg-options "-O3 -fopenmp-simd -fno-omit-frame-pointer" } */
/* Invoke X (P##n) for n in [0, 7]. */
#define REPEAT8(X, P) \
X (P##0) X (P##1) X (P##2) X (P##3) X (P##4) X (P##5) X (P##6) X (P##7)
/* Invoke X (n) for all octal n in [0, 39]. */
#define REPEAT40(X) \
REPEAT8 (X, 0) REPEAT8 (X, 1) REPEAT8 (X, 2) REPEAT8 (X, 3) REPEAT8 (X, 4)
volatile int testi, sink;
volatile void *ptr;
/* Take 2 stack arguments and throw to f3. */
void __attribute__ ((weak))
f1 (int x[40][100], int *y, int z1, int z2, int z3, int z4,
int z5, int z6, int z7, int z8)
{
/* A wild write to x and y. */
sink = z1;
sink = z2;
sink = z3;
sink = z4;
sink = z5;
sink = z6;
sink = z7;
sink = z8;
asm volatile ("" ::: "memory");
if (y[testi] == x[testi][testi])
throw 100;
}
/* Expect vector work to be done, with spilling of vector registers. */
void __attribute__ ((weak))
f2 (int x[40][100], int *y)
{
/* Create a true variable-sized frame. */
ptr = __builtin_alloca (testi + 40);
/* Try to force some spilling. */
#define DECLARE(N) int y##N = y[N];
REPEAT40 (DECLARE);
for (int j = 0; j < 20; ++j)
{
f1 (x, y, 1, 2, 3, 4, 5, 6, 7, 8);
#pragma omp simd
for (int i = 0; i < 100; ++i)
{
#define INC(N) x[N][i] += y##N;
REPEAT40 (INC);
}
}
}
/* Catch an exception thrown from f1, via f2. */
void __attribute__ ((weak))
f3 (int x[40][100], int *y, int *z)
{
volatile int extra = 111;
try
{
f2 (x, y);
}
catch (int val)
{
*z = val + extra;
}
}
static int x[40][100];
static int y[40];
static int z;
int
main (void)
{
f3 (x, y, &z);
if (z != 211)
__builtin_abort ();
return 0;
}

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@ -0,0 +1,4 @@
/* { dg-do run { target aarch64_sve_hw } } */
/* { dg-options "-O3 -fopenmp-simd -fomit-frame-pointer" } */
#include "catch_5.C"

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@ -1,3 +1,10 @@
2018-01-13 Richard Sandiford <richard.sandiford@linaro.org>
* 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.
2018-01-08 Michael Meissner <meissner@linux.vnet.ibm.com>
* config/rs6000/quad-float128.h (IBM128_TYPE): Explicitly use

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@ -23,3 +23,19 @@
#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))

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@ -216,12 +216,12 @@ _Unwind_IsExtendedContext (struct _Unwind_Context *context)
|| (context->flags & EXTENDED_CONTEXT_BIT));
}
/* Get the value of register INDEX as saved in CONTEXT. */
/* Get the value of register REGNO as saved in CONTEXT. */
inline _Unwind_Word
_Unwind_GetGR (struct _Unwind_Context *context, int index)
_Unwind_GetGR (struct _Unwind_Context *context, int regno)
{
int size;
int size, index;
_Unwind_Context_Reg_Val val;
#ifdef DWARF_ZERO_REG
@ -229,7 +229,7 @@ _Unwind_GetGR (struct _Unwind_Context *context, int index)
return 0;
#endif
index = DWARF_REG_TO_UNWIND_COLUMN (index);
index = DWARF_REG_TO_UNWIND_COLUMN (regno);
gcc_assert (index < (int) sizeof(dwarf_reg_size_table));
size = dwarf_reg_size_table[index];
val = context->reg[index];
@ -237,6 +237,14 @@ _Unwind_GetGR (struct _Unwind_Context *context, int index)
if (_Unwind_IsExtendedContext (context) && context->by_value[index])
return _Unwind_Get_Unwind_Word (val);
#ifdef DWARF_LAZY_REGISTER_VALUE
{
_Unwind_Word value;
if (DWARF_LAZY_REGISTER_VALUE (regno, &value))
return value;
}
#endif
/* This will segfault if the register hasn't been saved. */
if (size == sizeof(_Unwind_Ptr))
return * (_Unwind_Ptr *) (_Unwind_Internal_Ptr) val;