re PR tree-optimization/83221 (qsort comparator not anti-commutative: -2147483648, -2147483648)

	PR tree-optimization/83221
	* tree-ssa-reassoc.c (sort_by_operand_rank): Shift bb_rank
	down by 16.
	(init_reassoc): Formatting fix.

From-SVN: r255297

gcc/ChangeLog

 2017-12-01  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/83221
+	* tree-ssa-reassoc.c (sort_by_operand_rank): Shift bb_rank
+	down by 16.
+	(init_reassoc): Formatting fix.
+
 	PR sanitizer/81275
 	* tree-cfg.c (group_case_labels_stmt): Don't optimize away
 	C++ FE implicitly added __builtin_unreachable () until -Wreturn-type

gcc/tree-ssa-reassoc.c

@@ -543,7 +543,7 @@ sort_by_operand_rank (const void *pa, const void *pb)
 	    return -1;
 	  /* If neither is, compare bb_rank.  */
 	  if (bb_rank[bbb->index] != bb_rank[bba->index])
-	    return bb_rank[bbb->index] - bb_rank[bba->index];
+	    return (bb_rank[bbb->index] >> 16) - (bb_rank[bba->index] >> 16);
 	}
 
       bool da = reassoc_stmt_dominates_stmt_p (stmta, stmtb);