[Bug rtl-optimization/78546] [6/7 Regression] wrong code at -O2 and above

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78546

--- Comment #16 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Mon Nov 28 19:15:51 2016
New Revision: 242929

URL: https://gcc.gnu.org/viewcvs?rev=242929&root=gcc&view=rev
Log:
        PR rtl-optimization/78546
        * simplify-rtx.c (neg_const_int): When negating most negative
        number in mode wider than HOST_BITS_PER_WIDE_INT, use
        simplify_const_unary_operation to produce CONST_DOUBLE or
        CONST_WIDE_INT.
        (simplify_plus_minus): Hanlde the case where neg_const_int
        doesn't return a CONST_INT.

        * gcc.dg/torture/pr78546-1.c: New test.
        * gcc.dg/torture/pr78546-2.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/pr78546-1.c
    trunk/gcc/testsuite/gcc.dg/torture/pr78546-2.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/simplify-rtx.c
    trunk/gcc/testsuite/ChangeLog