[Bug c/24661] unable to find a register to spill in class NO_REGS on ia64

[Bug c/24661] unable to find a register to spill in class NO_REGS on ia64

[vapier at gentoo dot org]

------- Comment #1 from vapier at gentoo dot org  2005-11-03 23:51 -------
Created an attachment (id=10138)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=10138&action=view)
reduced test case, sym.c


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24661

[Bug c/24661] New: unable to find a register to spill in class NO_REGS on ia64

[vapier at gentoo dot org]

trying to build quake3 on ia64 ... reduced test case looks like this:

$ gcc -O2 -c sym.c
sym.c: In function `vtoa':
sym.c:28: error: unable to find a register to spill in class `FR_REGS'
sym.c:28: error: this is the insn:
(insn 12 3 13 0 (set (reg:DF 134 f6 [343])
        (float_truncate:DF (subreg:XF (reg/v:TI 112 in0 [orig:340 v ] [340])
0))) 39 {truncxfdf2} (insn_list 3 (nil))
    (expr_list:REG_DEAD (reg/v:TI 112 in0 [orig:340 v ] [340])
        (nil)))
sym.c:28: confused by earlier errors, bailing out

tested Gentoo 3.3.2 / 3.3.6 / 3.4.4 / 4.0.2, all fail same way


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           Summary: unable to find a register to spill in class NO_REGS on
                    ia64
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: vapier at gentoo dot org
  GCC host triplet: ia64-linux-gnu
GCC target triplet: ia64-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24661

[Bug c/24661] unable to find a register to spill in class NO_REGS on ia64

[vapier at gentoo dot org]

------- Comment #2 from vapier at gentoo dot org  2005-11-03 23:52 -------
Created an attachment (id=10139)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=10139&action=view)
full test case from quake3 source quake3-register-spill-insn.tar.bz2


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24661

[Bug target/24661] unable to find a register to spill in class NO_REGS on ia64

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2005-11-04 00:07 -------
I cannot reproduce this on the mainline.  Are you sure that this is not due to
a modification that gentoo has done?


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pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24661

[Bug target/24661] unable to find a register to spill in class NO_REGS on ia64

[vapier at gentoo dot org]

------- Comment #4 from vapier at gentoo dot org  2005-11-04 00:12 -------
i had a SuSE guy report the samething, but i'll go ahead and rebuild a vanilla
4.0.2 to be sure


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24661

[Bug target/24661] unable to find a register to spill in class NO_REGS on ia64

[vapier at gentoo dot org]

------- Comment #5 from vapier at gentoo dot org  2005-11-04 00:55 -------
ok, gcc-4.0.2 on Gentoo with no Gentoo patches fails same way

i'll see about creating a Debian chroot to doubly verify


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24661

[Bug target/24661] unable to find a register to spill in class NO_REGS on ia64

[pinskia at gcc dot gnu dot org]

------- Comment #6 from pinskia at gcc dot gnu dot org  2005-11-04 01:06 -------
Then maybe this has been fixed in 4.1.0 already.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24661

[Bug target/24661] unable to find a register to spill in class NO_REGS on ia64

[vapier at gentoo dot org]

------- Comment #7 from vapier at gentoo dot org  2005-11-04 01:46 -------
if that's the case, since this doesnt seem to be a regression (unless it worked
in like 3.2.x or older), does that mean i'm sol with 3.4.x/4.0.x ? :)


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24661

[Bug target/24661] unable to find a register to spill in class NO_REGS on ia64

[vapier at gentoo dot org]

------- Comment #8 from vapier at gentoo dot org  2005-11-04 02:09 -------
yes, debian 3.3.6-10 (3.3.6) and 3.4.4-9 (3.4.5 20051015) both fail in the same
way ... debian's 4.0.3 (4.0.3 20051023) however fails in a different way:

sym.c: In function 'vtoa':
sym.c:28: internal compiler error: in find_valid_class, at reload.c:719
Please submit a full bug report,

i'll see about installing gcc-4.1 on my Gentoo box


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24661

[Bug target/24661] unable to find a register to spill in class NO_REGS on ia64

[matz at suse dot de]

------- Comment #9 from matz at suse dot de  2005-11-09 14:49 -------
A shorter testcase (which at least breaks on SuSEs 3.3-hammer compiler) is:
---------------------------------------
typedef union value {
        long double d;
} Value;

double ld2d(Value v) {
        return v.d;
}
---------------------------------------

The problem seems to be that the register containing the union is TImode,
which gets converted to TFmode via subreg, which in turn is truncated to
DFmode via float_truncate, which somehow confuses gcc.


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matz at suse dot de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |matz at suse dot de


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24661

[Bug target/24661] unable to find a register to spill in class NO_REGS on ia64

[pinskia at gcc dot gnu dot org]

------- Comment #10 from pinskia at gcc dot gnu dot org  2005-11-09 15:23 -------
Hmm, do we have an ABI change in 4.1:
We get in 4.1.0:
ld2d:
        .prologue
        .body
        fnorm.d f8 = f8
        br.ret.sptk.many b0


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24661

[Bug target/24661] unable to find a register to spill in class NO_REGS on ia64

[matz at suse dot de]

------- Comment #11 from matz at suse dot de  2005-11-09 15:32 -------
You mean ABI change, because the input register seems to be f8, instead of
in0 (as would be need for this union)?  I'm not sure, but it looks fishy
at least.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24661

[Bug target/24661] unable to find a register to spill in class NO_REGS on ia64

[pinskia at gcc dot gnu dot org]

------- Comment #12 from pinskia at gcc dot gnu dot org  2005-11-09 15:57 -------
(In reply to comment #11)
> You mean ABI change, because the input register seems to be f8, instead of
> in0 (as would be need for this union)?  I'm not sure, but it looks fishy
> at least.
Actually it is not an ABI change as the 3.4's RTL looks like:
(insn 3 2 4 (set (reg/v:TI 340 [ v ])
        (reg:TI 136 f8 [ v ])) -1 (nil)
    (nil))

so it comes in as f8.

Note 4.0.3 20051105 fails the same way as your 4.0.3 does

So closing as fixed as this is not a regression.
Note gcc 4.1 produces the RTL as:
(insn 6 11 7 0 (set (reg:XF 340)
        (reg:XF 136 f8 [ v ])) -1 (nil)
    (nil))

Which is in the correct mode right away.


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pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
      Known to fail|3.3.2 3.3.6 3.4.4 4.0.2     |3.3.2 3.3.6 3.4.4 4.0.2
                   |                            |4.0.3
      Known to work|                            |4.1.0
         Resolution|                            |FIXED
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24661