https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92033
--- Comment #4 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> --- Author: rsandifo Date: Wed Oct 16 09:50:44 2019 New Revision: 277056 URL: https://gcc.gnu.org/viewcvs?rev=277056&root=gcc&view=rev Log: Deal with incoming POLY_INT_CST ranges (PR92033) This patch makes value_range_base::set convert POLY_INT_CST bounds into the worst-case INTEGER_CST bounds. The main case in which this gives useful ranges is a lower bound of A + B * X becoming A when B >= 0. E.g.: [32 + 16X, 100] -> [32, 100] [32 + 16X, 32 + 16X] -> [32, MAX] But the same thing can be useful for the upper bound with negative X coefficients. 2019-10-16 Richard Sandiford <richard.sandif...@arm.com> gcc/ PR middle-end/92033 * poly-int.h (constant_lower_bound_with_limit): New function. (constant_upper_bound_with_limit): Likewise. * doc/poly-int.texi: Document them. * tree-vrp.c (value_range_base::set): Convert POLY_INT_CST bounds into the worst-case INTEGER_CST bounds. Modified: trunk/gcc/ChangeLog trunk/gcc/doc/poly-int.texi trunk/gcc/poly-int.h trunk/gcc/tree-vrp.c
