[PATCH] Further OpenMP linear NO_COPYOUT or lastprivate changes (PR c++/67514)

[PATCH] Further OpenMP linear NO_COPYOUT or lastprivate changes (PR c++/67514)

[Jakub Jelinek]

Hi!

Apparently in some cases with template instantiation it is hard to get all
the DECL_EXPRs into OMP_FOR_PRE_BODY, I've been attempting it for a while
on the C++ FE side, but it broke lots of tests.

So, this instead deals with it at the gimplifier side, for combined for simd
if the IV is defined inside of the for, it is to be treated as NO_COPYOUT
or private instead of lastprivate.

Bootstrapped/regtested on x86_64-linux and i686-linux, committed to trunk
and 5 branch.

2015-09-10  Jakub Jelinek  <jakub@redhat.com>

	PR c++/67514
	* gimplify.c (gimplify_omp_for): For loop SIMD construct, if
	iterator is not explicitly determined, but is defined inside
	of the combined workshare region, handle it like if it has
	DECL_EXPR in OMP_FOR_PRE_BODY.

	* g++.dg/gomp/pr67514.C: New test.

--- gcc/gimplify.c.jj	2015-09-09 09:19:53.000000000 +0200
+++ gcc/gimplify.c	2015-09-09 13:16:14.575761790 +0200
@@ -7123,13 +7123,27 @@ gimplify_omp_for (tree *expr_p, gimple_s
 		  OMP_CLAUSE_LINEAR_NO_COPYOUT (c) = 1;
 		  flags |= GOVD_LINEAR_LASTPRIVATE_NO_OUTER;
 		}
+	      struct gimplify_omp_ctx *outer
+		= gimplify_omp_ctxp->outer_context;
+	      if (outer && !OMP_CLAUSE_LINEAR_NO_COPYOUT (c))
+		{
+		  if (outer->region_type == ORT_WORKSHARE
+		      && outer->combined_loop)
+		    {
+		      n = splay_tree_lookup (outer->variables,
+					     (splay_tree_key)decl);
+		      if (n != NULL && (n->value & GOVD_LOCAL) != 0)
+			{
+			  OMP_CLAUSE_LINEAR_NO_COPYOUT (c) = 1;
+			  flags |= GOVD_LINEAR_LASTPRIVATE_NO_OUTER;
+			}
+		    }
+		}
+
 	      OMP_CLAUSE_DECL (c) = decl;
 	      OMP_CLAUSE_CHAIN (c) = OMP_FOR_CLAUSES (for_stmt);
 	      OMP_FOR_CLAUSES (for_stmt) = c;
-	      
 	      omp_add_variable (gimplify_omp_ctxp, decl, flags);
-	      struct gimplify_omp_ctx *outer
-		= gimplify_omp_ctxp->outer_context;
 	      if (outer && !OMP_CLAUSE_LINEAR_NO_COPYOUT (c))
 		{
 		  if (outer->region_type == ORT_WORKSHARE
@@ -7166,9 +7180,16 @@ gimplify_omp_for (tree *expr_p, gimple_s
 		  if (outer->region_type == ORT_WORKSHARE
 		      && outer->combined_loop)
 		    {
-		      if (outer->outer_context
-			  && (outer->outer_context->region_type
-			      == ORT_COMBINED_PARALLEL))
+		      n = splay_tree_lookup (outer->variables,
+					     (splay_tree_key)decl);
+		      if (n != NULL && (n->value & GOVD_LOCAL) != 0)
+			{
+			  lastprivate = false;
+			  outer = NULL;
+			}
+		      else if (outer->outer_context
+			       && (outer->outer_context->region_type
+				   == ORT_COMBINED_PARALLEL))
 			outer = outer->outer_context;
 		      else if (omp_check_private (outer, decl, false))
 			outer = NULL;
--- gcc/testsuite/g++.dg/gomp/pr67514.C.jj	2015-09-09 13:32:37.941269205 +0200
+++ gcc/testsuite/g++.dg/gomp/pr67514.C	2015-09-09 13:32:17.000000000 +0200
@@ -0,0 +1,30 @@
+// PR c++/67514
+// { dg-do compile }
+// { dg-options "-fopenmp" }
+
+template <class T>
+void
+foo (T x, T y)
+{
+  #pragma omp parallel
+  #pragma omp for simd
+  for (T i = x; i < y; ++i)
+    ;
+  #pragma omp parallel
+  #pragma omp for simd collapse (2)
+  for (T i = x; i < y; ++i)
+    for (T j = x; j < y; j++)
+      ;
+}
+
+void
+bar (int *x, int *y)
+{
+  foo (x, y);
+}
+
+void
+baz (int x, int y)
+{
+  foo (x, y);
+}

	Jakub