[Bug middle-end/21616] New: ICE: unable to find a register to spill in class `FLOAT_REGS'

[Bug middle-end/21616] New: ICE: unable to find a register to spill in class `FLOAT_REGS'

[raj dot khem at gmail dot com]

GCC produced this ICE when the attached program was compiled. I tried the fix
from http://gcc.gnu.org/PR18641 but it did not fix the problem.

commandline options

-O2 -msoft-float -m64 -c


gcc output
=================================
a.c: In function `do_select':
a.c:12770: error: unable to find a register to spill in class `FLOAT_REGS'
a.c:12770: error: this is the insn:
(insn:HI 355 353 357 27 (set (mem/s:DI (plus:DI (reg/f:DI 31 31)
                (const_int 149 [0x95])) [4 fs_event.event_data2+0 S8 A8])
        (reg/v:DI 125 [ __timeout ])) 322 {*movdi_internal64} (nil)
    (nil))
a.c:12770: confused by earlier errors, bailing out

-- 
           Summary: ICE: unable to find a register to spill in class
                    `FLOAT_REGS'
           Product: gcc
           Version: 3.4.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: raj dot khem at gmail dot com
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: powerpc64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21616

[Bug middle-end/21616] ICE: unable to find a register to spill in class `FLOAT_REGS'

[raj dot khem at gmail dot com]

------- Additional Comments From raj dot khem at gmail dot com  2005-05-17 08:43 -------
Created an attachment (id=8907)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=8907&action=view)
testcase


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21616

[Bug middle-end/21616] ICE: unable to find a register to spill in class `FLOAT_REGS'

[amodra at bigpond dot net dot au]

------- Additional Comments From amodra at bigpond dot net dot au  2005-05-17 09:58 -------
Fails with 3.4.4 too

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
      Known to fail|                            |3.4.3 3.4.4
   Last reconfirmed|0000-00-00 00:00:00         |2005-05-17 09:58:34
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21616

[Bug target/21616] ICE: unable to find a register to spill in class `FLOAT_REGS'

[guptan at hotmail dot com]

------- Additional Comments From guptan at hotmail dot com  2005-05-20 17:43 -------
Alan, Andrew,

If any one of you have setup with gcc-4.0 handy, could you verify if this bug
exists there as well?

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21616

[Bug target/21616] [3.4 only] ICE: unable to find a register to spill in class `FLOAT_REGS'

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-05-21 00:14 -------
This was really fixed on the mainline by:
2005-01-07  David Edelsohn  <edelsohn@gnu.org>

        PR target/13674
        * config/rs6000/rs6000.c (rs6000_legitimize_reload_address):
        Convert non-word aligned offset address using ld/std into
        indirect address.

There is a work around on the 3.4 branch which looks like it is not working for this case for some 
reason.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|ICE: unable to find a       |[3.4 only] ICE: unable to
                   |register to spill in class  |find a register to spill in
                   |`FLOAT_REGS'                |class `FLOAT_REGS'
   Target Milestone|---                         |3.4.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21616

[Bug target/21616] [3.4 only] ICE: unable to find a register to spill in class `FLOAT_REGS'

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-05-21 00:19 -------
The work around for PR 13674 in the 3.4 branch is trying to use a FP register as that is what the work 
around says to do.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21616

[Bug target/21616] [3.4 only] ICE: unable to find a register to spill in class `FLOAT_REGS'

[guptan at hotmail dot com]

------- Additional Comments From guptan at hotmail dot com  2005-05-21 00:28 -------
Thanks Andrew.

[17:00] <ngupta> pinskia, yes I am trying to get an answer if PR21616 existed on
gcc-4.0 :)
[17:01] <pinskia> it might be worked around by optimizing it better :)
[17:01] <ngupta> I suspect its already fixed in rs6000.md, but dont want to go
over the whole setup thingie
[17:02] <pinskia> let me try it
[17:02] <ngupta> than I rather backport that from gcc-4.0
[17:05] <pinskia> did you try the patch for PR 15286?
[17:07] <ngupta> nope, lemme look
[17:08] <pinskia> oh, that will not help
[17:08] <pinskia> I know which bug this is, it has to do with ld not taking any
old offset but only aligned offsets
[17:08] <pinskia> let me find that patch
[17:08] <-- rosalesa has quit ("Leaving")
[17:13] <ngupta> oh ok, i m waiting
[17:14] --> jk- (~jk@toolbox.otago.ac.nz) has joined #ppc64
[17:14] <pinskia> ngupta: the patch for PR 13674 is the one which really fixed
the problem I think
[17:15] <pinskia> there is a workaround on the 3.4 branch for PR 13674 but it
looks like it does not work for this testcase :(
[17:16] <ngupta> yup, thats what I was abt to try
[17:16] <ngupta> -fnew-ra
[17:17] <pinskia> in fact I think the work around is causing the ICE to show up,
it is trying to use FP register because that is what the work around says to use
[17:19] <ngupta> so back to, could u try gcc-4.0
[17:20] <pinskia> I did and it worked
[17:20] <ngupta> I have started a build with this patch anyway
[17:20] <pinskia> you might need to revert the work around though
[17:20] <ngupta> oh ok, u mean patch for PR13674?
[17:21] <pinskia> the one which is on the 3.4 branch yes
[17:22] <ngupta> ok, got it
[17:22] <ngupta> thx, will update the bug after testing it
[17:24] <pinskia> 2004-03-10  Alan Modra  <amodra@bigpond.net.au>
[17:24] <pinskia>             Hartmut Penner  <hpenner@de.ibm.com>
[17:25] <ngupta> BTW, I will also CC dje/hpenner on this bug.
[17:25] <pinskia> one from http://gcc.gnu.org/ml/gcc-cvs/2004-03/msg00482.html
by the way

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hpenner at de dot ibm dot
                   |                            |com, dje at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21616

[Bug target/21616] [3.4 only] ICE: unable to find a register to spill in class `FLOAT_REGS'

[guptan at hotmail dot com]

------- Additional Comments From guptan at hotmail dot com  2005-05-24 20:39 -------
Andrew,

I was able to strip the worksround mentioned in
http://gcc.gnu.org/ml/gcc-cvs/2004-03/msg00482.html and apply the patch at  PR
target/13674 to avoid this bug.

If its of interest, I can post a patch for gcc-3.4 . I need to do a little bit
of cleanup before that.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21616