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
