re PR tree-optimization/83957 (ICE: Segmentation fault (in gimple_phi_arg))

	PR tree-optimization/83957
	* omp-expand.c (expand_omp_for_generic): Ignore virtual PHIs.  Remove
	semicolon after for body surrounded by braces.

	* gcc.dg/autopar/pr83957.c: New test.

From-SVN: r256967

gcc/ChangeLog

 2018-01-22  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/83957
+	* omp-expand.c (expand_omp_for_generic): Ignore virtual PHIs.  Remove
+	semicolon after for body surrounded by braces.
+
 	PR tree-optimization/83081
 	* profile-count.h (profile_probability::split): New method.
 	* dojump.c (do_jump_1) <case TRUTH_ANDIF_EXPR, case TRUTH_ORIF_EXPR>:

gcc/omp-expand.c

@@ -3156,6 +3156,9 @@ expand_omp_for_generic (struct omp_region *region,
 	      gphi *nphi;
 	      gphi *exit_phi = psi.phi ();
 
+	      if (virtual_operand_p (gimple_phi_result (exit_phi)))
+		continue;
+
 	      edge l2_to_l3 = find_edge (l2_bb, l3_bb);
 	      tree exit_res = PHI_ARG_DEF_FROM_EDGE (exit_phi, l2_to_l3);
 
@@ -3178,7 +3181,7 @@ expand_omp_for_generic (struct omp_region *region,
 	      add_phi_arg (nphi, exit_res, l2_to_l0, UNKNOWN_LOCATION);
 
 	      add_phi_arg (inner_phi, new_res, l0_to_l1, UNKNOWN_LOCATION);
-	    };
+	    }
 	}
 
       set_immediate_dominator (CDI_DOMINATORS, l2_bb,

gcc/testsuite/ChangeLog

 2018-01-22  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/83957
+	* gcc.dg/autopar/pr83957.c: New test.
+
 	PR tree-optimization/83081
 	* gcc.dg/predict-8.c: Adjust expected probability.
 

gcc/testsuite/gcc.dg/autopar/pr83957.c

+/* PR tree-optimization/83957 */
+/* { dg-do compile } */
+/* { dg-options "-O1 -ftree-parallelize-loops=2 -fno-tree-dce --param parloops-schedule=dynamic" } */
+
+void
+foo (int *x, int y)
+{
+  if (y < 0)
+    for (; y < 1; ++y)
+      x = &y;
+}