Hi Richard,
On 26.09.22 10:32, Richard Biener wrote:
On Fri, Sep 23, 2022 at 5:25 PM Tobias Burnus
<tob...@codesourcery.com><mailto:tob...@codesourcery.com> wrote:
This fixes a tree-sharing ICE. It seems as if all unshare_expr
I added were required in this case. [...]
looks like v1/v2/v3 are now unshared twice
According to the assert, that's not the case. 'var' is a memory
reference – and taking out any of the newly added unshare_expr
will give an ICE with the new *8.c testcase.
better done when its used. That said, please put the unshares
at places where new things are built, that's much clearer. That means
the 'outgoing' at
gimplify_assign (outgoing, teardown_call, &after_join);
The most localized change is the 'else' branch:
else
- v1 = v2 = v3 = var;
+ {
+ /* Note that 'var' might be a mem ref. */
+ v1 = unshare_expr (var);
+ v2 = unshare_expr (var);
+ v3 = unshare_expr (var);
+ incoming = unshare_expr (incoming);
+ outgoing = unshare_expr (outgoing);
+ }
But then I still need to unshare v1/v2/v3 at one other place. Namely:
Either in
- gimplify_assign (v1, setup_call, &before_fork);
+ gimplify_assign (unshare_expr (v1), setup_call, &before_fork);
or in
= build_call_expr_internal_loc (loc, IFN_GOACC_REDUCTION,
TREE_TYPE (var), 6, init_code,
unshare_expr (ref_to_res),
- v1, level, op, off);
+ unshare_expr (v1), level, op, off);
Alternatively, I keep the
else
v1 = v2 = v3 = var;
as is, possible adding the comment there, – and then add the unshare_expr
for v1/v2/v3/incoming to build_call_expr_internal_loc
*and* for v1/v2/v3/outgoind to gimplify_assign.
Which variant do you prefer?
(I have attached both – and the only difference is in omp-low.cc.)
(Certainly, other permutations are possible, one is the one in the first patch,
but I like either of the two new patches more.)
Tobias
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gcc/omp-low.cc | 15 +++++++++++----
gcc/testsuite/c-c++-common/goacc/reduction-7.c | 22 ++++++++++++++++++++++
gcc/testsuite/c-c++-common/goacc/reduction-8.c | 12 ++++++++++++
3 files changed, 45 insertions(+), 4 deletions(-)
diff --git a/gcc/omp-low.cc b/gcc/omp-low.cc
index d9f9aaebc0b..144ccd4bd3d 100644
--- a/gcc/omp-low.cc
+++ b/gcc/omp-low.cc
@@ -7631,7 +7631,14 @@ lower_oacc_reductions (location_t loc, tree clauses, tree level, bool inner,
incoming = build_simple_mem_ref (incoming);
}
else
- v1 = v2 = v3 = var;
+ {
+ /* Note that 'var' might be a mem ref. */
+ v1 = unshare_expr (var);
+ v2 = unshare_expr (var);
+ v3 = unshare_expr (var);
+ incoming = unshare_expr (incoming);
+ outgoing = unshare_expr (outgoing);
+ }
/* Determine position in reduction buffer, which may be used
by target. The parser has ensured that this is not a
@@ -7675,9 +7682,9 @@ lower_oacc_reductions (location_t loc, tree clauses, tree level, bool inner,
TREE_TYPE (var), 6, teardown_code,
ref_to_res, v3, level, op, off);
- gimplify_assign (v1, setup_call, &before_fork);
- gimplify_assign (v2, init_call, &after_fork);
- gimplify_assign (v3, fini_call, &before_join);
+ gimplify_assign (unshare_expr (v1), setup_call, &before_fork);
+ gimplify_assign (unshare_expr (v2), init_call, &after_fork);
+ gimplify_assign (unshare_expr (v3), fini_call, &before_join);
gimplify_assign (outgoing, teardown_call, &after_join);
}
diff --git a/gcc/testsuite/c-c++-common/goacc/reduction-7.c b/gcc/testsuite/c-c++-common/goacc/reduction-7.c
new file mode 100644
index 00000000000..482b0ab1984
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/reduction-7.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+
+/* PR middle-end/106982 */
+
+long long n = 100;
+int multiplicitive_n = 128;
+
+void test1(double *rand, double *a, double *b, double *c)
+{
+#pragma acc data copyin(a[0:10*multiplicitive_n], b[0:10*multiplicitive_n]) copyout(c[0:10])
+ {
+#pragma acc parallel loop
+ for (int i = 0; i < 10; ++i)
+ {
+ double temp = 1.0;
+#pragma acc loop vector reduction(*:temp)
+ for (int j = 0; j < multiplicitive_n; ++j)
+ temp *= a[(i * multiplicitive_n) + j] + b[(i * multiplicitive_n) + j];
+ c[i] = temp;
+ }
+ }
+}
diff --git a/gcc/testsuite/c-c++-common/goacc/reduction-8.c b/gcc/testsuite/c-c++-common/goacc/reduction-8.c
new file mode 100644
index 00000000000..2c3ed499d5b
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/reduction-8.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+
+/* PR middle-end/106982 */
+
+void test1(double *c)
+{
+ double reduced[5];
+#pragma acc parallel loop gang private(reduced)
+ for (int x = 0; x < 5; ++x)
+#pragma acc loop worker reduction(*:reduced)
+ for (int y = 0; y < 5; ++y) { }
+}
OpenACC: Fix reduction tree-sharing issue [PR106982]
The tree for var == incoming == outgound was
'MEM <double[5]> [(double *)&reduced]' which caused the ICE
"incorrect sharing of tree nodes".
PR middle-end/106982
gcc/ChangeLog:
* omp-low.cc (lower_oacc_reductions): Add some unshare_expr.
gcc/testsuite/ChangeLog:
* c-c++-common/goacc/reduction-7.c: New test.
* c-c++-common/goacc/reduction-8.c: New test.
gcc/omp-low.cc | 19 +++++++++++--------
gcc/testsuite/c-c++-common/goacc/reduction-7.c | 22 ++++++++++++++++++++++
gcc/testsuite/c-c++-common/goacc/reduction-8.c | 12 ++++++++++++
3 files changed, 45 insertions(+), 8 deletions(-)
diff --git a/gcc/omp-low.cc b/gcc/omp-low.cc
index d9f9aaebc0b..dc42c752017 100644
--- a/gcc/omp-low.cc
+++ b/gcc/omp-low.cc
@@ -7631,6 +7631,7 @@ lower_oacc_reductions (location_t loc, tree clauses, tree level, bool inner,
incoming = build_simple_mem_ref (incoming);
}
else
+ /* Note that 'var' might be a mem ref. */
v1 = v2 = v3 = var;
/* Determine position in reduction buffer, which may be used
@@ -7659,26 +7660,28 @@ lower_oacc_reductions (location_t loc, tree clauses, tree level, bool inner,
= build_call_expr_internal_loc (loc, IFN_GOACC_REDUCTION,
TREE_TYPE (var), 6, setup_code,
unshare_expr (ref_to_res),
- incoming, level, op, off);
+ unshare_expr (incoming),
+ level, op, off);
tree init_call
= build_call_expr_internal_loc (loc, IFN_GOACC_REDUCTION,
TREE_TYPE (var), 6, init_code,
unshare_expr (ref_to_res),
- v1, level, op, off);
+ unshare_expr (v1), level, op, off);
tree fini_call
= build_call_expr_internal_loc (loc, IFN_GOACC_REDUCTION,
TREE_TYPE (var), 6, fini_code,
unshare_expr (ref_to_res),
- v2, level, op, off);
+ unshare_expr (v2), level, op, off);
tree teardown_call
= build_call_expr_internal_loc (loc, IFN_GOACC_REDUCTION,
TREE_TYPE (var), 6, teardown_code,
- ref_to_res, v3, level, op, off);
+ ref_to_res, unshare_expr (v3),
+ level, op, off);
- gimplify_assign (v1, setup_call, &before_fork);
- gimplify_assign (v2, init_call, &after_fork);
- gimplify_assign (v3, fini_call, &before_join);
- gimplify_assign (outgoing, teardown_call, &after_join);
+ gimplify_assign (unshare_expr (v1), setup_call, &before_fork);
+ gimplify_assign (unshare_expr (v2), init_call, &after_fork);
+ gimplify_assign (unshare_expr (v3), fini_call, &before_join);
+ gimplify_assign (unshare_expr (outgoing), teardown_call, &after_join);
}
/* Now stitch things together. */
diff --git a/gcc/testsuite/c-c++-common/goacc/reduction-7.c b/gcc/testsuite/c-c++-common/goacc/reduction-7.c
new file mode 100644
index 00000000000..482b0ab1984
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/reduction-7.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+
+/* PR middle-end/106982 */
+
+long long n = 100;
+int multiplicitive_n = 128;
+
+void test1(double *rand, double *a, double *b, double *c)
+{
+#pragma acc data copyin(a[0:10*multiplicitive_n], b[0:10*multiplicitive_n]) copyout(c[0:10])
+ {
+#pragma acc parallel loop
+ for (int i = 0; i < 10; ++i)
+ {
+ double temp = 1.0;
+#pragma acc loop vector reduction(*:temp)
+ for (int j = 0; j < multiplicitive_n; ++j)
+ temp *= a[(i * multiplicitive_n) + j] + b[(i * multiplicitive_n) + j];
+ c[i] = temp;
+ }
+ }
+}
diff --git a/gcc/testsuite/c-c++-common/goacc/reduction-8.c b/gcc/testsuite/c-c++-common/goacc/reduction-8.c
new file mode 100644
index 00000000000..2c3ed499d5b
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/reduction-8.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+
+/* PR middle-end/106982 */
+
+void test1(double *c)
+{
+ double reduced[5];
+#pragma acc parallel loop gang private(reduced)
+ for (int x = 0; x < 5; ++x)
+#pragma acc loop worker reduction(*:reduced)
+ for (int y = 0; y < 5; ++y) { }
+}
