[committed] Fix OpenMP taskloop lowering (PR middle-end/86542)

[Jakub Jelinek]

Hi!

Another bug I've ran into while working on OpenMP 5.0 range for support.

For collapse(2) and higher taskloops, if there is any clause that
needs a cpyfn callback (e.g. firstprivate with non-POD, or VLA), we wouldn't
be copying over the temporaries needed for collapsed loop; without cpyfn
the default memcpy that copies the passed in data to the task arg area
handles that already.

Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux,
committed to trunk, queued for backports.

2018-07-17  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/86542
	* omp-low.c (create_task_copyfn): Copy over also fields corresponding
	to _looptemp_ clauses, other than the first two.

	* testsuite/libgomp.c++/pr86542.C: New test.

--- gcc/omp-low.c.jj	2018-06-22 19:17:12.219437746 +0200
+++ gcc/omp-low.c	2018-07-17 10:18:02.551015945 +0200
@@ -7026,6 +7026,7 @@ create_task_copyfn (gomp_task *task_stmt
   splay_tree_node n;
   struct omp_taskcopy_context tcctx;
   location_t loc = gimple_location (task_stmt);
+  size_t looptempno = 0;
 
   child_fn = gimple_omp_task_copy_fn (task_stmt);
   child_cfun = DECL_STRUCT_FUNCTION (child_fn);
@@ -7139,6 +7140,15 @@ create_task_copyfn (gomp_task *task_stmt
 	t = build2 (MODIFY_EXPR, TREE_TYPE (dst), dst, src);
 	append_to_statement_list (t, &list);
 	break;
+      case OMP_CLAUSE__LOOPTEMP_:
+	/* Fields for first two _looptemp_ clauses are initialized by
+	   GOMP_taskloop*, the rest are handled like firstprivate.  */
+        if (looptempno < 2)
+	  {
+	    looptempno++;
+	    break;
+	  }
+	/* FALLTHRU */
       case OMP_CLAUSE_FIRSTPRIVATE:
 	decl = OMP_CLAUSE_DECL (c);
 	if (is_variable_sized (decl))
@@ -7164,7 +7174,10 @@ create_task_copyfn (gomp_task *task_stmt
 	  src = decl;
 	dst = build_simple_mem_ref_loc (loc, arg);
 	dst = omp_build_component_ref (dst, f);
-	t = lang_hooks.decls.omp_clause_copy_ctor (c, dst, src);
+	if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE__LOOPTEMP_)
+	  t = build2 (MODIFY_EXPR, TREE_TYPE (dst), dst, src);
+	else
+	  t = lang_hooks.decls.omp_clause_copy_ctor (c, dst, src);
 	append_to_statement_list (t, &list);
 	break;
       case OMP_CLAUSE_PRIVATE:
--- libgomp/testsuite/libgomp.c++/pr86542.C.jj	2018-07-17 10:20:02.214127004 +0200
+++ libgomp/testsuite/libgomp.c++/pr86542.C	2018-07-17 10:19:39.207105565 +0200
@@ -0,0 +1,37 @@
+// PR middle-end/86542
+
+struct S { int s; S (); ~S (); S (const S &); };
+S s;
+
+S::S ()
+{
+}
+
+S::~S ()
+{
+}
+
+S::S (const S &x)
+{
+  s = x.s;
+}
+
+__attribute__((noipa)) void
+foo (int i, int j, int k, S s)
+{
+  if (i != 0 || j != 0 || k != 0 || s.s != 12)
+    __builtin_abort ();
+}
+
+int
+main ()
+{
+  volatile int inc = 16, jnc = 16, knc = 16;
+  s.s = 12;
+  #pragma omp taskloop collapse (3) firstprivate (s)
+  for (int i = 0; i < 16; i += inc)
+    for (int j = 0; j < 16; j += jnc)
+      for (int k = 0; k < 16; k += knc)
+	foo (i, j, k, s);
+  return 0;
+}

	Jakub