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Re: PR 10540


On Fri, 2003-07-25 at 00:18, Richard Sandiford wrote:
> Mark Mitchell <mark@codesourcery.com> writes:
> > Does anyone understand what is going wrong in PR 10540?
> > 
> > This is a MIPS PR, relating to a crash on invalid code.
> 
> Are you sure the code is invalid?  I thought it was testing for a
> "wrong-code" bug.
> 
> > Note that the crash only occurs with --enable-checking.  Is the check
> > valid?
> 
> FWIW, I think it's (correctly) detecting the problem that causes the
> execution failure.  We're storing a complex float value in a 64-bit
> register and referring to its components using subregs.  The subregs
> that refer to the high part of the register are not correctly reloaded,
> so we get the sort of thing you mentioned:
> 
>     (subreg:SF (reg:DI 3 v1) 0)
> 
> This is indeed invalid on big-endian 64-bit MIPS targets like irix6.
> 
> So really, it's a good thing that we're detecting this at compile time
> rather than silently generating wrong code. ;)
> 
> There's a separate PR to track the execution failure (6221) so maybe
> we could close 10540 and just keep that?

Agreed.  I've done as you suggest.

Thanks for the additional information!

-- 
Mark Mitchell
CodeSourcery, LLC
mark@codesourcery.com


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