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Re: [PATCH] Fix PR29519 Bad code on MIPS with -fnon-call-exceptions

Roger Sayle wrote:
Hi David,

On Sun, 22 Oct 2006, David Daney wrote:
2006-10-22  Richard Sandiford  <>
            David Daney  <>

PR middle-end/29519
* rtlanal.c (nonzero_address_p): Remove check for values wrapping.


This is ugly.  I agree with you and Richard that this optimization isn't
safe unless we can somehow prevent the RTL optimizers from creating the
problematic RTL that they currently do.  But I also worry how much benefit
some platforms get from the current unsafe transformation, and whether
there'd be an observable performance degradation with this fix.

I think its best to apply this patch to mainline to allow the benchmarking
folks test whether there's any change.  Likewise if someone could check
whether there are any/many code generation differences in cc1 files (or
similar), that'd go some way to silencing my potential concerns.

OK, I will try to do this right after I find GMP 4.1+ and MPFR 2.2+...

David Daney

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