[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[steven at gcc dot gnu dot org]

------- Comment #28 from steven at gcc dot gnu dot org  2009-06-14 19:54 -------
Created an attachment (id=17995)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=17995&action=view)
Patch agains r148322, works pre-RA only

Joern's original ifcvt.c patch only dealt with pre-reload if-conversion.  The
subsequent changes to make struct-equiv work for crossjumping and after reload,
made the code too complicated IMHO.

So I've gone back to the roots of the patch.  I've simplified things a bit --
mostly by using the DF machinery.  This new attached patch is far from complete
though.  The struct-equiv code should use rtx_equal_p_cb, but the
rtx_equal_p_cb needs to be modified first (to be more like for_each_rtx:
3-state and passing around a pointer to auxiliary data).  The local_reg_p stuff
should probably go into df-problems.c as a _p function.  And so on.

But the patch does work.  I wanted to let folks now that this bug is not yet
forgotten!


-- 

steven at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |steven at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070