re PR tree-optimization/67328 (range test rather than single bit test for code testin...

re PR tree-optimization/67328 (range test rather than single bit test for code testing enum values)

2017-06-13  Yury Gribov  <tetra2005@gmail.com>

gcc/
	PR tree-optimization/67328
	* fold-const.c (maskable_range_p): New function.
	(build_range_check): Generate bittests if possible.

gcc/testsuite/
	PR tree-optimization/67328
	* c-c++-common/fold-masked-cmp-1.c: New test.
	* c-c++-common/fold-masked-cmp-2.c: Likewise.
	* gcc.dg/pr46309.c: Fix pattern.
	* gcc.dg/pr46309-2.c: Likewise.

From-SVN: r249149