Re: DF_DU_CHAIN | DF_UD_CHAIN flags in new-ra

[Michael Matz <matz at suse dot de>]

Hi,

On Mon, 18 Aug 2003, Mukta Punjani, Noida wrote:

> In the call to df-analyse() in ra.c, passing DF_DU_CHAIN | DF_UD_CHAIN (any
> or both) results in ICE in compiling stress

Note that those flags can slow down the df_analyze process quite much.

> programs(advmilitary.i,advdomestic.i) with the following error report:
>
> [muktap@eagle test]$ ../objs/gcc/cc1 -O2 -ml -m4 -fnew-ra
> -fno-schedule-insns -fno-schedule-insns2 advmilitary.i
>  military_advisor_choose_tech assess_defense_quadratic
> advmilitary.i: In function `assess_defense_quadratic':
> advmilitary.i:1906: internal compiler error: in parts_to_webs_1, at
> ra-build.c:1981

It's possible that this is a problem with the incremental building.  The
later rounds of coloring just update the df information, instead of
rebuilding it from scratch.  Because I never used the def-use chains from
df.c I also didn't test if the updating mechanism works correctly on that
part of the information.  The strange thing though is, that the allocator
doesn't make use of this information anyway, so I wonder why it causes any
errors depending on the existence of it.  You would have to debug it
further.  The error itself means, that some sanity check went wrong.  Have
you tried also with the newregalloc-branch?


Ciao,
Michael.