[Bug middle-end/91680] Integer promotion quirk prevents efficient power of 2 division

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91680

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Tue Sep 10 08:15:46 2019
New Revision: 275587

URL: https://gcc.gnu.org/viewcvs?rev=275587&root=gcc&view=rev
Log:
        PR middle-end/91680
        * match.pd ((A / (1 << B)) -> (A >> B)): Allow widening cast from
        the shift type to type.

        * gcc.dg/tree-ssa/pr91680.c: New test.
        * g++.dg/torture/pr91680.C: New test.

Added:
    trunk/gcc/testsuite/g++.dg/torture/pr91680.C
    trunk/gcc/testsuite/gcc.dg/tree-ssa/pr91680.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/match.pd
    trunk/gcc/testsuite/ChangeLog