[committed] Fix OpenMP 5.0 task reduction lowering (PR ipa/88586)

[Jakub Jelinek]

Hi!

The following testcase ICEs with -fopenmp -flto, because two fields in task
reduction structure had NULL DECL_CONTEXT.  Fixed thusly, additionally I've
added type alignment adjustments that insert_field_into_struct normally
does; I couldn't use that function though, because I don't want the
reordering of fields that those functions do.

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

2018-12-29  Jakub Jelinek  <jakub@redhat.com>

	PR ipa/88586
	* omp-low.c (lower_omp_task_reductions): Set DECL_CONTEXT on field
	and ifield.  Update TYPE_ALIGN from alignment of field, ifield or
	bfield.

	* g++.dg/gomp/pr88586.C: New test.

--- gcc/omp-low.c.jj	2018-12-02 13:47:35.082132060 +0100
+++ gcc/omp-low.c	2018-12-28 11:40:47.214649851 +0100
@@ -7011,6 +7011,12 @@ lower_omp_task_reductions (omp_context *
       *last = field;
       DECL_CHAIN (field) = ifield;
       last = &DECL_CHAIN (ifield);
+      DECL_CONTEXT (field) = record_type;
+      if (TYPE_ALIGN (record_type) < DECL_ALIGN (field))
+	SET_TYPE_ALIGN (record_type, DECL_ALIGN (field));
+      DECL_CONTEXT (ifield) = record_type;
+      if (TYPE_ALIGN (record_type) < DECL_ALIGN (ifield))
+	SET_TYPE_ALIGN (record_type, DECL_ALIGN (ifield));
     }
   for (int pass = 0; pass < 2; pass++)
     {
@@ -7036,12 +7042,16 @@ lower_omp_task_reductions (omp_context *
 	  else
 	    SET_DECL_ALIGN (field, TYPE_ALIGN (type));
 	  DECL_CONTEXT (field) = record_type;
+	  if (TYPE_ALIGN (record_type) < DECL_ALIGN (field))
+	    SET_TYPE_ALIGN (record_type, DECL_ALIGN (field));
 	  *last = field;
 	  last = &DECL_CHAIN (field);
 	  tree bfield
 	    = build_decl (OMP_CLAUSE_LOCATION (c), FIELD_DECL, NULL_TREE,
 			  boolean_type_node);
 	  DECL_CONTEXT (bfield) = record_type;
+	  if (TYPE_ALIGN (record_type) < DECL_ALIGN (bfield))
+	    SET_TYPE_ALIGN (record_type, DECL_ALIGN (bfield));
 	  *last = bfield;
 	  last = &DECL_CHAIN (bfield);
 	}
--- gcc/testsuite/g++.dg/gomp/pr88586.C.jj	2018-12-28 11:48:01.085562936 +0100
+++ gcc/testsuite/g++.dg/gomp/pr88586.C	2018-12-28 11:47:54.031678152 +0100
@@ -0,0 +1,77 @@
+// PR ipa/88586
+// { dg-do compile { target lto } }
+// { dg-options "-fopenmp -flto" }
+
+extern "C" int omp_get_cancellation ();
+extern "C" int omp_get_thread_num ();
+extern "C" void abort ();
+
+struct A { A (); ~A (); A (const A &); static int cnt1, cnt2, cnt3; int a; };
+int A::cnt1;
+int A::cnt2;
+int A::cnt3;
+A::A () : a (0)
+{
+  #pragma omp atomic
+  cnt1++;
+}
+A::A (const A &x) : a (x.a)
+{
+  #pragma omp atomic
+  cnt2++;
+}
+A::~A ()
+{
+  #pragma omp atomic
+  cnt3++;
+}
+#pragma omp declare reduction (+: A: omp_out.a += omp_in.a)
+
+void
+foo (int x)
+{
+  A a, b[2];
+  int d = 1;
+  long int e[2] = { 1L, 1L };
+  int c = 0;
+  #pragma omp parallel
+  {
+    if (x && omp_get_thread_num () == 0)
+      {
+	for (int i = 0; i < 10000000; ++i)
+	  asm volatile ("");
+	c = 1;
+	#pragma omp cancel parallel
+      }
+    #pragma omp for reduction (task, +: a, b) reduction (task, *: d, e)
+    for (int i = 0; i < 64; i++)
+      #pragma omp task in_reduction (+: a, b) in_reduction (*: d, e)
+      {
+	a.a++;
+	b[0].a += 2;
+	b[1].a += 3;
+	d *= ((i & 7) == 0) + 1;
+	e[0] *= ((i & 7) == 3) + 1;
+	e[1] *= ((i & 3) == 2) + 1;
+      }
+    if (x && omp_get_cancellation ())
+      abort ();
+  }
+  if (!c)
+    {
+      if (a.a != 64 || b[0].a != 128 || b[1].a != 192)
+	abort ();
+      if (d != 256 || e[0] != 256L || e[1] != 65536L)
+	abort ();
+    }
+}
+
+int
+main ()
+{
+  int c1 = A::cnt1, c2 = A::cnt2, c3 = A::cnt3;
+  volatile int zero = 0;
+  foo (zero);
+  if (A::cnt1 + A::cnt2 - c1 - c2 != A::cnt3 - c3)
+    abort ();
+}

	Jakub