[Bug tree-optimization/45232] [4.6 regression] tree reassociation introduces undefined overflow

["rguenth at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #6 from rguenth at gcc dot gnu dot org  2010-08-12 10:38 -------
Subject: Bug 45232

Author: rguenth
Date: Thu Aug 12 10:38:05 2010
New Revision: 163190

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=163190
Log:
2010-08-12  Richard Guenther  <rguenther@suse.de>

        PR tree-optimization/45232
        * tree-ssa-reassoc.c (can_reassociate_p): Disable re-association
        for types with undefined overflow.
        (reassociate_bb): Allow re-associating of bit and min/max
        operations for types with undefined overflow.
        * tree-ssa-forwprop.c (associate_plusminus): New function.
        (tree_ssa_forward_propagate_single_use_vars): Call it.

        * gcc.dg/tree-ssa/pr44133.c: Adjust warning location.
        * gcc.dg/tree-ssa/loop-7.c: Adjust.
        * gcc.dg/tree-ssa/reassoc-1.c: XFAIL.
        * gcc.dg/tree-ssa/reassoc-20.c: Add reassoc-1.c variant with
        unsigned arithmetic.
        * gcc.dg/tree-ssa/reassoc-14.c: Use unsigned arithmetic.
        * gcc.dg/tree-ssa/reassoc-15.c: Likewise.
        * gcc.dg/tree-ssa/reassoc-18.c: Likewise.
        * gcc.dg/tree-ssa/reassoc-2.c: XFAIL.
        * gcc.dg/tree-ssa/reassoc-21.c: Add reassoc-2.c variant with
        unsigned arithmetic.
        * gcc.dg/tree-ssa/reassoc-6.c: XFAIL.
        * gcc.dg/tree-ssa/reassoc-22.c: Add reassoc-6.c variant with
        unsigned arithmetic.
        * gcc.dg/tree-ssa/reassoc-7.c: Use unsigned arithmetic.
        * gcc.dg/tree-ssa/reassoc-9.c: XFAIL.
        * gcc.dg/tree-ssa/reassoc-23.c: Add reassoc-9.c variant with
        unsigned arithmetic.
        * gcc.dg/tree-ssa/ssa-pre-2.c: Adjust.
        * gcc.dg/tree-ssa/negate.c: Adjust.
        * gcc.dg/vect/vect-1.c: Adjust.
        * gfortran.dg/reassoc_6.f: XFAIL.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-20.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-21.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-22.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-23.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/tree-ssa/loop-7.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/negate.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/pr44133.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-1.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-14.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-15.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-18.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-2.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-6.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-7.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-9.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-2.c
    trunk/gcc/testsuite/gcc.dg/vect/vect-1.c
    trunk/gcc/testsuite/gfortran.dg/reassoc_6.f
    trunk/gcc/tree-ssa-forwprop.c
    trunk/gcc/tree-ssa-reassoc.c


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45232