Status of GCC 4.3 on Alpha (Debian)

Status of GCC 4.3 on Alpha (Debian)

[Martin Michlmayr]

I recently compiled the Debian archive on Alpha using trunk to identify
new issues before GCC 4.3 is released.  I actually started a first
attempt in the middle of November but had to stop after about 2500
packages because of hardware problems.  During my first attempt, I
found the following Alpha related compiler bugs:

 - PR34132: internal consistency failure (invalid rtl sharing found in
   the insn)
   Fixed by Jakub Jelinek

 - PR34171: Segfault in df_chain_remove_problem with -O3 on alpha
   Fixed by Seongbae Park

My second attempt was more successful and I compiled the entire Debian
archive (over 7000 packages that need to be compiled).  I compiled the
archive with optimization set to -O3 and found the following ICEs with
trunk from 20071212:

 - PR34571: Segfault in alpha_expand_mov at -O3 (1 failure)
   Filed two days ago so no progress yet

 - PR33410: ICE in iv_analyze_expr, at loop-iv.c (14 failures)
   This is actually a known regression from 4.1 that has became a
   problem for us when we moved to GCC 4.2.  Unfortunately, nobody
   seems to be investigating this issue.

 - PR34467: ICE in lookup_subvars_for_var, at tree-flow-inline.h:1586
   (5 failures)
   Aldy has a patch but I'm not sure what the status is.
 - PR34585: ICE in remove_useless_stmts_1, at tree-cfg.c:1863 (1 failure)
   Probably the same issue
 - PR34465: verify_stmts failed (incorrect sharing of tree nodes) (1
   failure)
   I believe this is fixed by Aldy's patch too

If someone can look at PR34571 and particularly at PR33410, Alpha will
be in pretty good shape for 4.3.  I should also note that a couple of
software packages failed to build because of problems with their
testsuites.  I still have to investigate these failures.

The testing was done with 4.3.0 20071212 r130789 from 2007-12-12 to
2007-12-24.

Thanks to Alexander Wong of St Hugh's College, Oxford for giving me
remote access to an Alpha, and to Florian Lohoff for hosting two
DS25 Alpha servers that Richard Higson kindly donated to Debian.
-- 
Martin Michlmayr
http://www.cyrius.com/