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Re: SRA bit-field optimization


On Oct  8, 2007, John David Anglin <dave@hiauly1.hia.nrc.ca> wrote:

> On Sun, 07 Oct 2007, Alexandre Oliva wrote:
>> On Oct  6, 2007, Richard Sandiford <rsandifo@nildram.co.uk> wrote:
>> 
>> > Ah, thanks.  I did have a quick look at it, and it seemed to be caused
>> > by a missing conversion at the tree level.  Expand was being given
>> > a BIT_AND_EXPR with a DImode-typed result and HImode-typed operand.
>> > I didn't try to track down where it was coming from.  So it does seem
>> > to be a tree-level bug after all.
>> 
>> Yep, fixed in the revised patch below.

> The 991118-1.c and longlong.c fails are still present on
> hppa-unknown-linux-gnu with the revised patch.

Since there isn't AFAIK a simulator for hppa-elf and the failure isn't
present on mipsisa32-elf, I'm going to need some help tracking this
down.  I've stared at the final tree code, the final RTL and the
generated assembly for 991118-1.c on hppa-linux-gnu for a couple of
hours already, and I haven't been able to locate any error :-(

Could you please let me know which comparison fails, what we're
comparing with and what the computed value is, such that I can stand a
better chance of fixing the problem?


Thanks,

-- 
Alexandre Oliva         http://www.lsd.ic.unicamp.br/~oliva/
FSF Latin America Board Member         http://www.fsfla.org/
Red Hat Compiler Engineer   aoliva@{redhat.com, gcc.gnu.org}
Free Software Evangelist  oliva@{lsd.ic.unicamp.br, gnu.org}


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