Hi!
gimplify_scan_omp_clauses was already calling gimplify_expr with false as
last argument to make sure it is not an SSA_NAME, but as the testcases show,
that is not enough, SSA_NAME temporaries created during that gimplification
can be reused too and we can't allow SSA_NAMEs to be used across OpenMP
region boundaries, as we can only firstprivatize decls.
Fixed by temporarily disabling into_ssa.
Bootstrapped/regtested on x86_64-linux and i686-linux, committed to trunk.
2021-02-10 Jakub Jelinek <ja...@redhat.com>
PR middle-end/99007
* gimplify.c (gimplify_scan_omp_clauses): For MEM_REF on reductions,
temporarily disable gimplify_ctxp->into_ssa around gimplify_expr
calls.
* g++.dg/gomp/pr99007.C: New test.
* gcc.dg/gomp/pr99007-1.c: New test.
* gcc.dg/gomp/pr99007-2.c: New test.
* gcc.dg/gomp/pr99007-3.c: New test.
--- gcc/gimplify.c.jj 2021-01-26 08:57:46.473172059 +0100
+++ gcc/gimplify.c 2021-02-09 17:15:29.391887803 +0100
@@ -8781,13 +8781,17 @@ gimplify_scan_omp_clauses (tree *list_p,
if (TREE_CODE (decl) == MEM_REF)
{
tree type = TREE_TYPE (decl);
+ bool saved_into_ssa = gimplify_ctxp->into_ssa;
+ gimplify_ctxp->into_ssa = false;
if (gimplify_expr (&TYPE_MAX_VALUE (TYPE_DOMAIN (type)), pre_p,
NULL, is_gimple_val, fb_rvalue, false)
== GS_ERROR)
{
+ gimplify_ctxp->into_ssa = saved_into_ssa;
remove = true;
break;
}
+ gimplify_ctxp->into_ssa = saved_into_ssa;
tree v = TYPE_MAX_VALUE (TYPE_DOMAIN (type));
if (DECL_P (v))
{
@@ -8797,13 +8801,16 @@ gimplify_scan_omp_clauses (tree *list_p,
decl = TREE_OPERAND (decl, 0);
if (TREE_CODE (decl) == POINTER_PLUS_EXPR)
{
+ gimplify_ctxp->into_ssa = false;
if (gimplify_expr (&TREE_OPERAND (decl, 1), pre_p,
NULL, is_gimple_val, fb_rvalue, false)
== GS_ERROR)
{
+ gimplify_ctxp->into_ssa = saved_into_ssa;
remove = true;
break;
}
+ gimplify_ctxp->into_ssa = saved_into_ssa;
v = TREE_OPERAND (decl, 1);
if (DECL_P (v))
{
--- gcc/testsuite/g++.dg/gomp/pr99007.C.jj 2021-02-09 17:20:36.487454483
+0100
+++ gcc/testsuite/g++.dg/gomp/pr99007.C 2021-02-09 17:26:08.779739476 +0100
@@ -0,0 +1,18 @@
+// PR middle-end/99007
+// { dg-additional-options "-Wno-div-by-zero" }
+
+template <typename T>
+void
+bar (T *)
+{
+ T s[0/0];
+ #pragma omp teams distribute parallel for reduction(+:s) allocate(s)
+ for (int i = 0; i < 8; i++)
+ ;
+}
+
+void
+foo (long *a)
+{
+ bar (a);
+}
--- gcc/testsuite/gcc.dg/gomp/pr99007-1.c.jj 2021-02-09 17:22:57.456878452
+0100
+++ gcc/testsuite/gcc.dg/gomp/pr99007-1.c 2021-02-09 17:22:38.101094856
+0100
@@ -0,0 +1,13 @@
+/* PR middle-end/99007 */
+
+void
+bar (int n)
+{
+ int i;
+ long s[n];
+ for (i = 0; i < n; i++)
+ s[i] = 0;
+ #pragma omp teams distribute parallel for reduction(+:s) allocate(s)
+ for (i = 0; i < 8; i++)
+ s[3]++;
+}
--- gcc/testsuite/gcc.dg/gomp/pr99007-2.c.jj 2021-02-09 17:23:00.449844997
+0100
+++ gcc/testsuite/gcc.dg/gomp/pr99007-2.c 2021-02-09 17:22:44.682021286
+0100
@@ -0,0 +1,15 @@
+/* PR middle-end/99007 */
+
+int
+bar (int n)
+{
+ int s[n];
+ int i, j;
+ for (i = 0; i < n; i++)
+ s[i] = 0;
+ #pragma omp teams distribute parallel for reduction(+:s) private (j)
+ for (i = 0; i < 8; i++)
+ for (j = 0; j < n; j++)
+ s[j] += i;
+ return s[0] + s[n - 1];
+}
--- gcc/testsuite/gcc.dg/gomp/pr99007-3.c.jj 2021-02-09 17:23:03.315812951
+0100
+++ gcc/testsuite/gcc.dg/gomp/pr99007-3.c 2021-02-09 17:22:52.281936308
+0100
@@ -0,0 +1,16 @@
+/* PR middle-end/99007 */
+
+int
+bar (int n)
+{
+ int s[n];
+ int i, j;
+ for (i = 0; i < n; i++)
+ s[i] = 0;
+ #pragma omp parallel reduction(+:s) num_threads(2)
+ #pragma omp parallel for reduction(+:s) private (j)
+ for (i = 0; i < 8; i++)
+ for (j = 0; j < n; j++)
+ s[j] += i;
+ return s[0] + s[n - 1];
+}
Jakub
