[Bug tree-optimization/23429] Operations involving unsigneds could be simplified

[Bug tree-optimization/23429] Operations involving unsigneds could be simplified

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2005-12-13 04:30 -------
Fixed in 4.2.0 by:
2005-12-12  Jeff Law  <law@redhat.com>

        * tree-ssa-dom.c (simplify_rhs_and_lookup_avail_expr): Remove
        reassociation code.
        * passes.c (init_optimization_passes): Run reassociation again
        after loop optimizations.

2005-12-12  Daniel Berlin  <dberlin@dberlin.org>

        * tree-ssa-dom.c (thread_across_edge): Canonicalize condition
        if necessary.
        (optimize_stmt): Ditto.
        (canonicalize_comparison): New function.
        * tree-ssa-operands.c (swap_tree_operands): Make external.
        (get_expr_operands): Stop auto-canonicalization.
        * tree-ssa-reassoc.c: Rewrite.
        (init_optimization_passes):
        * tree-flow.h (swap_tree_operands): Prototype.
        * Makefile.in (tree-ssa-reassoc.o): Update dependencies.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.2.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23429

[Bug tree-optimization/23429] Operations involving unsigneds could be simplified

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-08-17 01:36 -------
Confirmed, this is basically the same issue as PR 22312.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |22312
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-08-17 01:36:50
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23429

[Bug tree-optimization/23429] Operations involving unsigneds could be simplified

[pinskia at physics dot uc dot edu]

------- Additional Comments From pinskia at physics dot uc dot edu  2005-08-16 21:10 -------
Subject: Re:  New: Operations involving unsigneds could be simplified

> 
> This could just return 1.
> 
> $ cat unsigned-arith.c
> int foo(unsigned int *a, unsigned int *b, unsigned int *c)
> {
>     unsigned int s1, s2;
> 
>     s1 = *a + *b;
>     s2 = *c + *b;
> 
>     return s1 + *c == s2 + *a;
> }

The issue here is the reassociater needs to be a fully reassociater
and that has a couple of different bugs about this filed already.

-- Pinski


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23429