[Bug rtl-optimization/51023] [4.7 Regression] likely integer wrong code bug

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51023

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-11-10 15:36:52 UTC ---
Author: jakub
Date: Thu Nov 10 15:36:48 2011
New Revision: 181257

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=181257
Log:
    PR rtl-optimization/51023
    * combine.c (simplify_comparison) <case SIGN_EXTEND>: Don't use
    val_signbit_known_clear_p for signed comparison narrowing
    optimization.  Don't check for non-VOIDmode, use
    HWI_COMPUTABLE_MODE_P macro.
    <case ZERO_EXTEND>: Don't check for non-VOIDmode.
    Optimize even when const_op is equal to GET_MODE_MASK (mode),
    don't optimize if const_op is negative.

    * gcc.c-torture/execute/pr51023.c: New test.

Added:
    trunk/gcc/testsuite/gcc.c-torture/execute/pr51023.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/combine.c
    trunk/gcc/testsuite/ChangeLog