* Re: Reload problem, advice required
@ 2004-09-11 10:48 Ulrich Weigand
2004-09-11 13:25 ` *** SPAM *** " Jon Beniston
0 siblings, 1 reply; 3+ messages in thread
From: Ulrich Weigand @ 2004-09-11 10:48 UTC (permalink / raw)
To: jon; +Cc: gcc
Jon Beniston wrote:
>(insn 4 936 932 0
>/home/Jon/build-gcc2/excess-elf/mall-enabled/libstdc++-v3/include/bits/istre
>am.tcc:865 (parallel [
> (set (mem/s:HI (reg:HI 1 ra) [52 __pos+0 S2 A16])
> (reg:HI 5 r5))
> (set (mem/s:HI (plus:HI (reg/f:HI 229)
> (const_int 2 [0x2])) [52 __pos+2 S2 A16])
> (reg:HI 6 r6))
> (set (mem/s:HI (plus:HI (reg/f:HI 229)
> (const_int 4 [0x4])) [52 __pos+4 S2 A16])
> (reg:HI 7 r7))
> ]) 26 {*sm} (insn_list 875 (nil))
> (nil))
I assume this is a store-multiple pattern that uses a
match_parallel with only the first operand explicitly
matched by a match_operand? It is a known problem that
reload doesn't handle such patterns correctly; in some
cases, register replacements are performed only in the
operand explicitly matches, not in the implicit operands
allowed by the match_parallel.
This is apparently difficult to fix; all back-ends using
load/store multiple patterns currently work around the
problem by either disabling them until after reload (so
that the prolog/epilog expanders can still use them),
like s390, or by having not one single match_parallel
pattern but multiple separate patterns, one for each
number of registers, like rs6000.
Bye,
Ulrich
--
Dr. Ulrich Weigand
weigand@informatik.uni-erlangen.de
^ permalink raw reply [flat|nested] 3+ messages in thread
* RE: *** SPAM *** Re: Reload problem, advice required
2004-09-11 10:48 Reload problem, advice required Ulrich Weigand
@ 2004-09-11 13:25 ` Jon Beniston
0 siblings, 0 replies; 3+ messages in thread
From: Jon Beniston @ 2004-09-11 13:25 UTC (permalink / raw)
To: 'Ulrich Weigand'; +Cc: gcc
Hi,
> I assume this is a store-multiple pattern that uses a
> match_parallel with only the first operand explicitly matched
> by a match_operand?
Yep.
> the prolog/epilog expanders can still use them), like s390,
> or by having not one single match_parallel pattern but
> multiple separate patterns, one for each number of registers,
> like rs6000.
Yep. Adding multile patterns has fixed it. Thanks a lot.
Cheers,
JonB
^ permalink raw reply [flat|nested] 3+ messages in thread
* Reload problem, advice required
@ 2004-09-11 3:49 Jon Beniston
0 siblings, 0 replies; 3+ messages in thread
From: Jon Beniston @ 2004-09-11 3:49 UTC (permalink / raw)
To: gcc
Hi,
I'm am seeing the following compiler abort on a new port I'm working on:
libstdc++-v3/include/bits/istream.tcc:124: internal compiler error: in relo
ad_combine_note_use, at postreload.c:1082
Which I believe is occuring because a pseduo register is detected in an
instruction after global register allocation.
The offending instruction in the .lreg dump is:
(insn 4 875 932 0
/home/Jon/build-gcc2/excess-elf/mall-enabled/libstdc++-v3/include/bits/istre
am.tcc:865 (parallel [
(set (mem/s:HI (reg/f:HI 229) [52 __pos+0 S2 A16])
(reg:HI 5 r5))
(set (mem/s:HI (plus:HI (reg/f:HI 229)
(const_int 2 [0x2])) [52 __pos+2 S2 A16])
(reg:HI 6 r6))
(set (mem/s:HI (plus:HI (reg/f:HI 229)
(const_int 4 [0x4])) [52 __pos+4 S2 A16])
(reg:HI 7 r7))
]) 26 {*sm} (insn_list 875 (nil))
(expr_list:REG_DEAD (reg:HI 7 r7)
(expr_list:REG_DEAD (reg:HI 6 r6)
(expr_list:REG_DEAD (reg:HI 5 r5)
(nil)))))
And in the .greg dump:
(insn 4 936 932 0
/home/Jon/build-gcc2/excess-elf/mall-enabled/libstdc++-v3/include/bits/istre
am.tcc:865 (parallel [
(set (mem/s:HI (reg:HI 1 ra) [52 __pos+0 S2 A16])
(reg:HI 5 r5))
(set (mem/s:HI (plus:HI (reg/f:HI 229)
(const_int 2 [0x2])) [52 __pos+2 S2 A16])
(reg:HI 6 r6))
(set (mem/s:HI (plus:HI (reg/f:HI 229)
(const_int 4 [0x4])) [52 __pos+4 S2 A16])
(reg:HI 7 r7))
]) 26 {*sm} (insn_list 875 (nil))
(nil))
I am assuming that the pseudo register references (reg/f:HI 229) shouldn't
appear in the .greg dump. Is that correct? If so, what is likely to be the
cause of this problem? Is it likely to be something I have done wrong in my
machine specific code, or is it a more general problem? Any pointers on
where I should be looking would be greatly appreciated.
I working off the 3.4.2 sources.
Cheers,
JonB
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2004-09-11 11:10 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-09-11 10:48 Reload problem, advice required Ulrich Weigand
2004-09-11 13:25 ` *** SPAM *** " Jon Beniston
-- strict thread matches above, loose matches on Subject: below --
2004-09-11 3:49 Jon Beniston
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).