[Bug middle-end/64309] if (1 & (1 << n)) not simplified to if (n == 0)

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64309

--- Comment #14 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Author: mpolacek
Date: Tue Dec 16 18:29:01 2014
New Revision: 218787

URL: https://gcc.gnu.org/viewcvs?rev=218787&root=gcc&view=rev
Log:
    PR middle-end/64309
    * match.pd: Add ((1 << A) & 1) != 0 -> A == 0 and
    ((1 << A) & 1) == 0 -> A != 0.

    * gcc.dg/pr64309.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/pr64309.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/match.pd
    trunk/gcc/testsuite/ChangeLog