2017-07-25 Richard Biener <rguenther@suse.de>

	PR tree-optimization/81510
	* tree-vect-loop.c (vect_is_simple_reduction): When the
	reduction stmt is not inside the loop bail out.

	* gcc.dg/torture/pr81510.c: New testcase.
	* gcc.dg/torture/pr81510-2.c: Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@250504 138bc75d-0d04-0410-961f-82ee72b054a4

5 files changed, 81 insertions, 19 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 82c7edc595d..880b10e2955 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,11 @@
 2017-07-25  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/81510
+	* tree-vect-loop.c (vect_is_simple_reduction): When the
+	reduction stmt is not inside the loop bail out.
+
+2017-07-25  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/81303
 	* tree-vect-loop-manip.c (vect_loop_versioning): Build
 	profitability check against LOOP_VINFO_NITERSM1.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 2762ae5b70f..f75186947ad 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2017-07-25  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/81510
+	* gcc.dg/torture/pr81510.c: New testcase.
+	* gcc.dg/torture/pr81510-2.c: Likewise.
+
 2017-07-25  Martin Liska  <mliska@suse.cz>
 
 	PR ipa/81520
diff --git a/gcc/testsuite/gcc.dg/torture/pr81510-2.c b/gcc/testsuite/gcc.dg/torture/pr81510-2.c
new file mode 100644
index 00000000000..7e2bc9866f7
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr81510-2.c
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+
+typedef int h;
+typedef int k;
+int a;
+int b;
+int c;
+int d;
+int e;
+int f(int g)
+{
+  h *i = &e;
+  k *j;
+  if (d -= b)
+    for (; *j; *j += 1) {
+	g = g || (a = e ? c = (__UINTPTR_TYPE__)j : 0) + *i;
+	i = &d;
+    }
+}
diff --git a/gcc/testsuite/gcc.dg/torture/pr81510.c b/gcc/testsuite/gcc.dg/torture/pr81510.c
new file mode 100644
index 00000000000..c93c4683629
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr81510.c
@@ -0,0 +1,29 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-w" } */
+
+typedef int d;
+typedef int f;
+typedef long h;
+int a;
+int b;
+int c;
+int e()
+{
+  f *g;
+  h i;
+  for (;;)
+    if (g)
+      for (; b; b++) {
+	  g = c;
+	  if (a &= c) {
+	      d *j = &b;
+	      h k;
+	      for (; i; i++) {
+		  *g ?: (*j = k);
+		  g = &a;
+	      }
+	      for (; i <= 3; i++)
+		;
+	  }
+      }
+}
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index 931f1b5872e..5b1b8a1fdee 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -2813,27 +2813,29 @@ vect_is_simple_reduction (loop_vec_info loop_info, gimple *phi,
       return NULL;
     }
 
+  if (! flow_bb_inside_loop_p (loop, gimple_bb (def_stmt)))
+    return NULL;
+
   nloop_uses = 0;
   auto_vec<gphi *, 3> lcphis;
-  if (flow_bb_inside_loop_p (loop, gimple_bb (def_stmt)))
-    FOR_EACH_IMM_USE_FAST (use_p, imm_iter, name)
-      {
-	gimple *use_stmt = USE_STMT (use_p);
-	if (is_gimple_debug (use_stmt))
-	  continue;
-	if (flow_bb_inside_loop_p (loop, gimple_bb (use_stmt)))
-	  nloop_uses++;
-	else
-	  /* We can have more than one loop-closed PHI.  */
-	  lcphis.safe_push (as_a <gphi *> (use_stmt));
-	if (nloop_uses > 1)
-	  {
-	    if (dump_enabled_p ())
-	      dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-			       "reduction used in loop.\n");
-	    return NULL;
-	  }
-      }
+  FOR_EACH_IMM_USE_FAST (use_p, imm_iter, name)
+    {
+      gimple *use_stmt = USE_STMT (use_p);
+      if (is_gimple_debug (use_stmt))
+	continue;
+      if (flow_bb_inside_loop_p (loop, gimple_bb (use_stmt)))
+	nloop_uses++;
+      else
+	/* We can have more than one loop-closed PHI.  */
+	lcphis.safe_push (as_a <gphi *> (use_stmt));
+      if (nloop_uses > 1)
+	{
+	  if (dump_enabled_p ())
+	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+			     "reduction used in loop.\n");
+	  return NULL;
+	}
+    }
 
   /* If DEF_STMT is a phi node itself, we expect it to have a single argument
      defined in the inner loop.  */