Re: more hpux fun (ICE building libgcc2.c in __fixunsdfdi)

["John David Anglin" <dave at hiauly1 dot hia dot nrc dot ca>]

> Still can't bootstrap hppa2.0-hp-hpux10.20.
> 
> We get further than before (the duplicate-include problem is gone),
> but still bomb early in stage 2.  The latest failure is
> 
> ./xgcc -B./ -B/u/jbuck/cvs-gcc-hp/hppa2.0-hp-hpux10.20/bin/ -isystem \
> /u/jbuck/cvs-gcc-hp/hppa2.0-hp-hpux10.20/include -O2   -DIN_GCC \
> -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes \
> -isystem ./include  -fPIC -g1  -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED  \
> -I. -I. -I/u/jbuck/gnu/src/cvs/gcc/gcc -I/u/jbuck/gnu/src/cvs/gcc/gcc/. \
> -I/u/jbuck/gnu/src/cvs/gcc/gcc/config \
> -I/u/jbuck/gnu/src/cvs/gcc/gcc/../include -DUSE_COLLECT2 -DL_fixunsdfdi \
> -c /u/jbuck/gnu/src/cvs/gcc/gcc/libgcc2.c -o libgcc/./_fixunsdfdi.o
> /u/jbuck/gnu/src/cvs/gcc/gcc/libgcc2.c: In function `__fixunsdfdi':
> /u/jbuck/gnu/src/cvs/gcc/gcc/libgcc2.c:949: Internal compiler error in propagate
> _one_insn, at flow.c:3790

This is caused by the insn which saves the pic offset table register in
the prologue being dead.  It is a result of a lack of a use for the
register in the epilogue.  This causes the insn which restores this
register after a function call to be deleted.  When this happens, the
saving insn may become dead and cause the error.

I posted a patch to fix the problem here:
<http://gcc.gnu.org/ml/gcc-patches/2001-01/msg01482.html>.  I believe
Jeff is also working on a solution.  There are reasons why fixing the
problem is tricky and I think you will just have to hold on a bit until
the details are resolved and fully tested.  

Dave
-- 
J. David Anglin                                  dave.anglin@nrc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6605)