[Bug lto/43342] New: lto1: internal compiler error: failed to reclaim unneeded function

[Bug lto/43342] New: lto1: internal compiler error: failed to reclaim unneeded function

[pluto at agmk dot net]

here's a simple lto test on object with virtual methods:

$ LANG=C make clean all CPPFLAGS=-DCRASH
rm -f *.o *.s *.ii m
g++-4.5 -Wall -g2 -O3 -DCRASH a.cpp -c -flto
g++-4.5 -Wall -g2 -O3 -DCRASH m.cpp -c -flto
g++-4.5 -Wall -g2 -O3 -DCRASH a.o m.o -o m -fwhopr --save-temps -fverbose-asm
__base_dtor /6(-1) @0x7f82e673dea0 (clone of __base_dtor /3)
availability:not_available (25 after inlining) (7 after inlining) needed
address_taken body externally_visible finalized
  called by: main/1
  calls:
lto1: internal compiler error: failed to reclaim unneeded function
Please submit a full bug report,
with preprocessed source if appropriate.


another variant of testcase with dynamic object allocation compiles
but virtual calls aren't optimized.

$ LANG=C make clean all
rm -f *.o *.s *.ii m
g++-4.5 -Wall -g2 -O3  a.cpp -c -flto
g++-4.5 -Wall -g2 -O3  m.cpp -c -flto
g++-4.5 -Wall -g2 -O3  a.o m.o -o m -fwhopr --save-temps -fverbose-asm

m_a.wpa.s fragments:

indirect foo() call not optimized.

        movq    $_ZTV1X+16, (%rax)
        call    *_ZTV1X+32(%rip)

bar() call optimized :)

        movq    %rbp, %rsi
        movl    $.LC1, %edi
        xorl    %eax, %eax
        call    printf

indirect destructor call not optimized.

        movq    (%rbx), %rax
        movq    %rbx, %rdi
        call    *8(%rax)


-- 
           Summary: lto1: internal compiler error: failed to reclaim
                    unneeded function
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pluto at agmk dot net
 GCC build triplet: x86_64-gnu-linux
  GCC host triplet: x86_64-gnu-linux
GCC target triplet: x86_64-gnu-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43342

[Bug lto/43342] lto1: internal compiler error: failed to reclaim unneeded function

[pluto at agmk dot net]

------- Comment #1 from pluto at agmk dot net  2010-03-12 10:05 -------
Created an attachment (id=20093)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20093&action=view)
testcase.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43342

[Bug lto/43342] lto1: internal compiler error: failed to reclaim unneeded function

[pluto at agmk dot net]

------- Comment #2 from pluto at agmk dot net  2010-03-12 10:11 -------
i should mention that at -O2 with object allocated on *stack*
lto does a nice job and optimize indirect calls in main():

        call    _ZN1X3fooEv
        (...)
        call    _ZN1X3barEv
        (...)
        call    _ZN1XD1Ev

with dynamic allocation there's no progress.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43342

[Bug lto/43342] lto1: internal compiler error: failed to reclaim unneeded function

[rguenth at gcc dot gnu dot org]

------- Comment #3 from rguenth at gcc dot gnu dot org  2010-03-12 11:23 -------
I'm not sure you are supposed to mix -flto and -fwhopr (though it probably
just works).  This is btw the most prominent ICE I see when building SPEC
with -fwhopr and checking enabled.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hubicka at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |lto
   Last reconfirmed|0000-00-00 00:00:00         |2010-03-12 11:23:46
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43342

[Bug lto/43342] lto1: internal compiler error: failed to reclaim unneeded function

[astrange at ithinksw dot com]

------- Comment #4 from astrange at ithinksw dot com  2010-03-14 23:33 -------
This happens building ffmpeg --enable-shared with -fwhopr. I can make a
testcase out of that if needed.


-- 

astrange at ithinksw dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |astrange at ithinksw dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43342

[Bug lto/43342] lto1: internal compiler error: failed to reclaim unneeded function

[pluto at agmk dot net]

------- Comment #5 from pluto at agmk dot net  2010-03-15 11:28 -------
(In reply to comment #3)
> I'm not sure you are supposed to mix -flto and -fwhopr (though it probably
> just works).  This is btw the most prominent ICE I see when building SPEC
> with -fwhopr and checking enabled.

mixing -flto/-fwhopr is unnecessary. pure -fwhopr is enough to reproduce an
ICE.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43342

[Bug lto/43342] lto1: internal compiler error: failed to reclaim unneeded function

[rguenth at gcc dot gnu dot org]

------- Comment #6 from rguenth at gcc dot gnu dot org  2010-04-26 11:32 -------
The problem no longer occurs.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43342

[Bug lto/43342] lto1: internal compiler error: failed to reclaim unneeded function

[hubicka at gcc dot gnu dot org]

------- Comment #7 from hubicka at gcc dot gnu dot org  2010-04-26 12:41 -------
-fwhopr and -flto are intended to be interchangeable at link time. So it does
not matter with what flag you build the .o objects.
The problem was fixed by the clone streaming fix I submitted last week.

Honza


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43342