[Bug rtl-optimization/56494] [4.8 Regression] ICE in simplify_truncation, at simplify-rtx.c:619

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56494

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-03-05 06:04:23 UTC ---
Author: jakub
Date: Tue Mar  5 06:04:14 2013
New Revision: 196451

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=196451
Log:
    PR rtl-optimization/56494
    * simplify-rtx.c (simplify_truncation): If C is narrower than A,
    optimize (truncate:A (subreg:B (truncate:C X) 0)) into
    (subreg:A (truncate:C X) 0) instead of (truncate:A X).

    * gcc.dg/pr56494.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/pr56494.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/simplify-rtx.c
    trunk/gcc/testsuite/ChangeLog