re PR tree-optimization/43833 (false warning: array subscript is above array bounds with -O3)
PR tree-optimization/43833
* tree-vrp.c (range_int_cst_p): New.
(range_int_cst_singleton_p): New.
(extract_range_from_binary_expr): Optimize BIT_AND_EXPR case
when both operands are constants. Use range_int_cst_p in
BIT_IOR_EXPR case.
testsuite/
PR tree-optimization/43833
gcc.dg/Warray-bounds-8.c: New test case.