re PR tree-optimization/81655 (new test case gcc.dg/tree-ssa/pr81588.c fails on powerpc64)

	PR tree-optimization/81655
	PR tree-optimization/81588
	* tree-ssa-reassoc.c (optimize_range_tests_var_bound): Handle also
	the case when ranges[i].low and high are 1 for unsigned type with
	precision 1.

From-SVN: r250849

gcc/ChangeLog

 2017-08-03  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/81655
+	PR tree-optimization/81588
+	* tree-ssa-reassoc.c (optimize_range_tests_var_bound): Handle also
+	the case when ranges[i].low and high are 1 for unsigned type with
+	precision 1.
+
 	PR middle-end/81052
 	* omp-low.c (diagnose_sb_0): Handle flag_openmp_simd like flag_openmp.
 	(pass_diagnose_omp_blocks::gate): Enable also for flag_openmp_simd.

gcc/tree-ssa-reassoc.c

@@ -2918,11 +2918,22 @@ optimize_range_tests_var_bound (enum tree_code opcode, int first, int length,
 
   for (i = 0; i < length; i++)
     {
+      bool in_p = ranges[i].in_p;
       if (ranges[i].low == NULL_TREE
-	  || ranges[i].high == NULL_TREE
-	  || !integer_zerop (ranges[i].low)
-	  || !integer_zerop (ranges[i].high))
+	  || ranges[i].high == NULL_TREE)
 	continue;
+      if (!integer_zerop (ranges[i].low)
+	  || !integer_zerop (ranges[i].high))
+	{
+	  if (ranges[i].exp
+	      && TYPE_PRECISION (TREE_TYPE (ranges[i].exp)) == 1
+	      && TYPE_UNSIGNED (TREE_TYPE (ranges[i].exp))
+	      && integer_onep (ranges[i].low)
+	      && integer_onep (ranges[i].high))
+	    in_p = !in_p;
+	  else
+	    continue;
+	}
 
       gimple *stmt;
       tree_code ccode;
@@ -2964,7 +2975,7 @@ optimize_range_tests_var_bound (enum tree_code opcode, int first, int length,
 	default:
 	  continue;
 	}
-      if (ranges[i].in_p)
+      if (in_p)
 	ccode = invert_tree_comparison (ccode, false);
       switch (ccode)
 	{