[Bug middle-end/28753] [4.2 regression] ICE in extract_insn, at recog.c:2075 on powerpc

[dje at gcc dot gnu dot org]

------- Comment #11 from dje at gcc dot gnu dot org  2006-08-24 18:19 -------
Created an attachment (id=12128)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=12128&action=view)
allow immediate load into CRs

Ulrich Weigand pointed out the instruction that is failing is a secondary
reload already.  Reload fundamentally does not check predicates, so that is a
red herring.

The bug is an omission in the movcc_internal1 pattern.  The secondary reload is
trying to load an immediate into a GPR, but the pattern does not provide any
alternative for immediate constants.  Although PPC CRs themselves generally
cannot materialize an immediate constant, a GPR in CC mode loading a constant
must be described by the pattern, which it was not.

PPC CRs can materialize two constants easily: all zeros and all ones.  The
particular case in this bug is (const_int 0) and that will be more common, so I
also added an alternative to materialize that directly without the secondary
reload.


-- 

dje at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #12118|0                           |1
        is obsolete|                            |
         AssignedTo|unassigned at gcc dot gnu   |dje at gcc dot gnu dot org
                   |dot org                     |
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28753