re PR tree-optimization/92252 (ICE: Segmentation fault (in vect_stmt_to_vectorize))

2019-10-28  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/92252
	* tree-vect-slp.c (vect_get_and_check_slp_defs): Adjust
	STMT_VINFO_REDUC_IDX when swapping operands.

	* gcc.dg/torture/pr92252.c: New testcase.

From-SVN: r277517

gcc/ChangeLog

 2019-10-28  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/92252
+	* tree-vect-slp.c (vect_get_and_check_slp_defs): Adjust
+	STMT_VINFO_REDUC_IDX when swapping operands.
+
+2019-10-28  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/92241
 	* tree-vect-loop.c (vect_fixup_scalar_cycles_with_patterns): When
 	we failed to update the reduction index do not use the pattern

gcc/testsuite/ChangeLog

 2019-10-28  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/92252
+	* gcc.dg/torture/pr92252.c: New testcase.
+
+2019-10-28  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/92241
 	* gcc.dg/torture/pr92241.c: New testcase.
 

gcc/testsuite/gcc.dg/torture/pr92252.c

+/* { do-do compile } */
+/* { dg-additional-options "-ftree-vectorize" } */
+
+long int ar;
+int dt;
+
+long int
+pc (unsigned long int q3, int zw)
+{
+  long int em = 0;
+
+  while (zw < 1)
+    {
+      q3 = zw * 2ul;
+      if (q3 != 0)
+        for (ar = 0; ar < 2; ++ar)
+          em = dt;
+
+      ++zw;
+    }
+
+  return em;
+}

gcc/tree-vect-slp.c

@@ -563,6 +563,10 @@ again:
 	    {
 	      swap_ssa_operands (stmt, gimple_assign_rhs2_ptr (stmt),
 				 gimple_assign_rhs3_ptr (stmt));
+	      if (STMT_VINFO_REDUC_IDX (stmt_info) == 1)
+		STMT_VINFO_REDUC_IDX (stmt_info) = 2;
+	      else if (STMT_VINFO_REDUC_IDX (stmt_info) == 2)
+		STMT_VINFO_REDUC_IDX (stmt_info) = 1;
 	      bool honor_nans = HONOR_NANS (TREE_OPERAND (cond, 0));
 	      code = invert_tree_comparison (TREE_CODE (cond), honor_nans);
 	      gcc_assert (code != ERROR_MARK);