Hi!
On 2022-03-01T17:46:20+0100, I wrote:
> On 2022-01-13T10:54:16+0100, I wrote:
>> On 2019-05-08T14:51:57+0100, Julian Brown <jul...@codesourcery.com> wrote:
>>> - The "addressable" bit is set during the kernels conversion pass for
>>> variables that have "create" (alloc) clauses created for them in the
>>> synthesised outer data region (instead of in the front-end, etc.,
>>> where it can't be done accurately). Such variables actually have
>>> their address taken during transformations made in a later pass
>>> (omp-low, I think), but there's a phase-ordering problem that means
>>> the flag should be set earlier.
>>
>> The actual issue is a bit different, but yes, there is a problem.
>> The related ICE has also been reported as <https://gcc.gnu.org/PR100280>
>> "ICE in lower_omp_target, at omp-low.c:12287". [...]
We've resolved all such known ICEs -- but still have open
<https://gcc.gnu.org/PR104892> "OpenACC 'kernels' decomposition:
wrong-code cases unless manually making certain variables addressable".
This is avoided by:
> workaround patches like
> we have on the og11 development branch:
> - "Avoid introducing 'create' mapping clauses for loop index variables in
> kernels regions",
> - "Run all kernels regions with GOMP_MAP_FORCE_TOFROM mappings
> synchronously",
> - "Fix for is_gimple_reg vars to 'data kernels'"
..., but the misbehavior is visible without the workaround patches, for
example on the master branch.
Pushed to master branch commit 535afbd959bc72de85fca36ba6417f075cca1018
"OpenACC 'kernels' decomposition: wrong-code cases unless manually making
certain variables addressable [PR104892]", see attached, to "Document a
few examples of the status quo".
Grüße
Thomas
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>From 535afbd959bc72de85fca36ba6417f075cca1018 Mon Sep 17 00:00:00 2001
From: Thomas Schwinge <tho...@codesourcery.com>
Date: Fri, 11 Mar 2022 15:11:25 +0100
Subject: [PATCH] OpenACC 'kernels' decomposition: wrong-code cases unless
manually making certain variables addressable [PR104892]
Document a few examples of the status quo.
PR middle-end/104892
libgomp/
* testsuite/libgomp.oacc-c-c++-common/kernels-decompose-1.c: Point
to PR104892.
* testsuite/libgomp.oacc-c-c++-common/default-1.c: Likewise,
enable '--param=openacc-kernels=decompose' and adjust.
* testsuite/libgomp.oacc-c-c++-common/kernels-reduction-1.c:
Likewise.
* testsuite/libgomp.oacc-c-c++-common/parallel-dims.c: Likewise.
* testsuite/libgomp.oacc-fortran/kernels-reduction-1.f90:
Likewise.
---
.../libgomp.oacc-c-c++-common/default-1.c | 14 ++++++--
.../kernels-decompose-1.c | 4 +--
.../kernels-reduction-1.c | 8 ++++-
.../libgomp.oacc-c-c++-common/parallel-dims.c | 34 +++++++++++++------
.../kernels-reduction-1.f90 | 15 +++++++-
5 files changed, 59 insertions(+), 16 deletions(-)
diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/default-1.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/default-1.c
index 0ac8d7132d4..fed65c8dccc 100644
--- a/libgomp/testsuite/libgomp.oacc-c-c++-common/default-1.c
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/default-1.c
@@ -1,3 +1,5 @@
+/* { dg-additional-options "--param=openacc-kernels=decompose" } */
+
/* { dg-additional-options "-fopt-info-all-omp" }
{ dg-additional-options "-foffload=-fopt-info-all-omp" } */
@@ -63,6 +65,8 @@ int test_parallel ()
int test_kernels ()
{
int val = 2;
+ /*TODO <https://gcc.gnu.org/PR104892> */
+ (volatile int *) &val;
int ary[32];
int ondev = 0;
@@ -71,12 +75,18 @@ int test_kernels ()
/* val defaults to copy, ary defaults to copy. */
#pragma acc kernels copy(ondev) /* { dg-line l_compute[incr c_compute] } */
- /* { dg-note {variable 'i' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_compute$c_compute } */
- /* { dg-optimized {assigned OpenACC seq loop parallelism} {} { target *-*-* } l_compute$c_compute } */
+ /* { dg-note {variable 'ondev\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_compute$c_compute } */
+ /* { dg-note {variable 'val\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_compute$c_compute } */
{
+ /* { dg-note {beginning 'gang-single' part in OpenACC 'kernels' region} {} { target *-*-* } .+1 } */
ondev = acc_on_device (acc_device_not_host);
+ /* { dg-optimized {assigned OpenACC seq loop parallelism} {} { target { c++ && { ! __OPTIMIZE__ } } } .-1 }
+ ..., as without optimizations, we're not inlining the C++ 'acc_on_device' wrapper. */
#pragma acc loop /* { dg-line l_loop_i[incr c_loop_i] } */
+ /* { dg-note {forwarded loop nest in OpenACC 'kernels' region to 'parloops' for analysis} {} { target *-*-* } l_loop_i$c_loop_i } */
+ /* { dg-note {variable 'i' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_loop_i$c_loop_i } */
/* { dg-note {variable 'i' in 'private' clause isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_loop_i$c_loop_i } */
+ /* { dg-optimized {assigned OpenACC seq loop parallelism} {} { target *-*-* } l_loop_i$c_loop_i } */
for (unsigned i = 0; i < 32; i++)
{
ary[i] = val;
diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/kernels-decompose-1.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/kernels-decompose-1.c
index eb424776b6b..3db59e8a75c 100644
--- a/libgomp/testsuite/libgomp.oacc-c-c++-common/kernels-decompose-1.c
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/kernels-decompose-1.c
@@ -29,12 +29,12 @@ static int g2;
static void f1 ()
{
int a = 0;
- /*TODO Without making 'a' addressable, for GCN offloading we will not see the expected value copied out. (But it does work for nvptx offloading, strange...) */
+ /*TODO <https://gcc.gnu.org/PR104892> */
(volatile int *) &a;
#define N 123
int b[N] = { 0 };
unsigned long long f1;
- /*TODO See above. */
+ /*TODO <https://gcc.gnu.org/PR104892> */
(volatile void *) &f1;
#pragma acc kernels /* { dg-line l_compute[incr c_compute] } */
diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/kernels-reduction-1.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/kernels-reduction-1.c
index fbd9815f683..e7b2817a391 100644
--- a/libgomp/testsuite/libgomp.oacc-c-c++-common/kernels-reduction-1.c
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/kernels-reduction-1.c
@@ -1,6 +1,8 @@
/* Verify that a simple, explicit acc loop reduction works inside
a kernels region. */
+/* { dg-additional-options "--param=openacc-kernels=decompose" } */
+
/* { dg-additional-options "-fopt-info-all-omp" }
{ dg-additional-options "-foffload=-fopt-info-all-omp" } */
@@ -17,12 +19,16 @@ int
main ()
{
int i, red = 0;
+ /*TODO <https://gcc.gnu.org/PR104892> */
+ (volatile int *) &red;
#pragma acc kernels /* { dg-line l_compute1 } */
- /* { dg-optimized {assigned OpenACC seq loop parallelism} {} { target *-*-* } l_compute1 } */
+ /* { dg-note {variable 'red\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_compute1 } */
{
#pragma acc loop reduction (+:red) /* { dg-line l_loop_i1 } */
+ /* { dg-note {forwarded loop nest in OpenACC 'kernels' region to 'parloops' for analysis} {} { target *-*-* } l_loop_i1 } */
/* { dg-note {variable 'i' in 'private' clause isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_loop_i1 } */
+ /* { dg-optimized {assigned OpenACC seq loop parallelism} {} { target *-*-* } l_loop_i1 } */
for (i = 0; i < N; i++)
red++;
}
diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/parallel-dims.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/parallel-dims.c
index f9c7aed3a56..75e8cb510cc 100644
--- a/libgomp/testsuite/libgomp.oacc-c-c++-common/parallel-dims.c
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/parallel-dims.c
@@ -1,6 +1,8 @@
/* OpenACC parallelism dimensions clauses: num_gangs, num_workers,
vector_length. */
+/* { dg-additional-options "--param=openacc-kernels=decompose" } */
+
/* { dg-additional-options "-fopt-info-all-omp" }
{ dg-additional-options "-foffload=-fopt-info-all-omp" } */
@@ -640,20 +642,26 @@ int main ()
kernels. */
{
int gangs_min, gangs_max, workers_min, workers_max, vectors_min, vectors_max;
+ /*TODO <https://gcc.gnu.org/PR104892> */
+ (volatile int *) &gangs_min, &gangs_max, &workers_min, &workers_max, &vectors_min, &vectors_max;
gangs_min = workers_min = vectors_min = INT_MAX;
gangs_max = workers_max = vectors_max = INT_MIN;
#pragma acc kernels /* { dg-line l_compute[incr c_compute] } */
- /* { dg-note {variable 'i' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_compute$c_compute } */
- /* { dg-optimized {assigned OpenACC seq loop parallelism} {} { target *-*-* } l_compute$c_compute } */
+ /* { dg-note {variable 'gangs_max\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_compute$c_compute } */
+ /* { dg-note {variable 'workers_max\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_compute$c_compute } */
+ /* { dg-note {variable 'vectors_max\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_compute$c_compute } */
{
- /* This is to make the OpenACC kernels construct unparallelizable. */
- asm volatile ("" : : : "memory");
-
#pragma acc loop /* { dg-line l_loop_i[incr c_loop_i] } */ \
reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max)
+ /* { dg-note {forwarded loop nest in OpenACC 'kernels' region to 'parloops' for analysis} {} { target *-*-* } l_loop_i$c_loop_i } */
+ /* { dg-note {variable 'i' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_loop_i$c_loop_i } */
/* { dg-note {variable 'i' in 'private' clause isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_loop_i$c_loop_i } */
+ /* { dg-optimized {assigned OpenACC seq loop parallelism} {} { target *-*-* } l_loop_i$c_loop_i } */
for (int i = 100; i > -100; --i)
{
+ /* This is to make the loop unparallelizable. */
+ asm volatile ("" : : : "memory");
+
gangs_min = gangs_max = acc_gang ();
workers_min = workers_max = acc_worker ();
vectors_min = vectors_max = acc_vector ();
@@ -674,23 +682,29 @@ int main ()
#define WORKERS 5
#define VECTORS 13
int gangs_min, gangs_max, workers_min, workers_max, vectors_min, vectors_max;
+ /*TODO <https://gcc.gnu.org/PR104892> */
+ (volatile int *) &gangs_min, &gangs_max, &workers_min, &workers_max, &vectors_min, &vectors_max;
gangs_min = workers_min = vectors_min = INT_MAX;
gangs_max = workers_max = vectors_max = INT_MIN;
#pragma acc kernels /* { dg-line l_compute[incr c_compute] } */ \
num_gangs (gangs) \
num_workers (WORKERS) \
vector_length (VECTORS)
- /* { dg-note {variable 'i' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_compute$c_compute } */
- /* { dg-optimized {assigned OpenACC seq loop parallelism} {} { target *-*-* } l_compute$c_compute } */
+ /* { dg-note {variable 'gangs_max\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_compute$c_compute } */
+ /* { dg-note {variable 'workers_max\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_compute$c_compute } */
+ /* { dg-note {variable 'vectors_max\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_compute$c_compute } */
{
- /* This is to make the OpenACC kernels construct unparallelizable. */
- asm volatile ("" : : : "memory");
-
#pragma acc loop /* { dg-line l_loop_i[incr c_loop_i] } */ \
reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max)
+ /* { dg-note {forwarded loop nest in OpenACC 'kernels' region to 'parloops' for analysis} {} { target *-*-* } l_loop_i$c_loop_i } */
+ /* { dg-note {variable 'i' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_loop_i$c_loop_i } */
/* { dg-note {variable 'i' in 'private' clause isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_loop_i$c_loop_i } */
+ /* { dg-optimized {assigned OpenACC seq loop parallelism} {} { target *-*-* } l_loop_i$c_loop_i } */
for (int i = 100; i > -100; --i)
{
+ /* This is to make the loop unparallelizable. */
+ asm volatile ("" : : : "memory");
+
gangs_min = gangs_max = acc_gang ();
workers_min = workers_max = acc_worker ();
vectors_min = vectors_max = acc_vector ();
diff --git a/libgomp/testsuite/libgomp.oacc-fortran/kernels-reduction-1.f90 b/libgomp/testsuite/libgomp.oacc-fortran/kernels-reduction-1.f90
index 6ff740efc32..89bae49c94c 100644
--- a/libgomp/testsuite/libgomp.oacc-fortran/kernels-reduction-1.f90
+++ b/libgomp/testsuite/libgomp.oacc-fortran/kernels-reduction-1.f90
@@ -2,6 +2,8 @@
! { dg-do run }
+! { dg-additional-options "--param=openacc-kernels=decompose" }
+
! { dg-additional-options "-fopt-info-all-omp" }
! { dg-additional-options "-foffload=-fopt-info-all-omp" } */
@@ -13,17 +15,28 @@
program reduction
integer, parameter :: n = 20
integer :: i, red
+ !TODO <https://gcc.gnu.org/PR104892>
+ call make_addressable (red)
red = 0
!$acc kernels ! { dg-line l_compute1 } */
- ! { dg-optimized {assigned OpenACC seq loop parallelism} {} { target *-*-* } l_compute1 }
+ ! { dg-note {variable 'red\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_compute1 }
!$acc loop reduction (+:red) ! { dg-line l_loop_i1 }
+ ! { dg-note {forwarded loop nest in OpenACC 'kernels' region to 'parloops' for analysis} {} { target *-*-* } l_loop_i1 }
! { dg-note {variable 'i' in 'private' clause isn't candidate for adjusting OpenACC privatization level: not addressable} {} { target *-*-* } l_loop_i1 }
+ ! { dg-optimized {assigned OpenACC seq loop parallelism} {} { target *-*-* } l_loop_i1 }
do i = 1, n
red = red + 1
end do
!$acc end kernels
if (red .ne. n) stop 1
+
+contains
+
+ subroutine make_addressable (v)
+ integer :: v ! by reference
+ end subroutine make_addressable
+
end program reduction
--
2.34.1
