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Re: Reload Issue -- I can't believe we haven't hit this before
- From: Eric Botcazou <ebotcazou at libertysurf dot fr>
- To: law at redhat dot com
- Cc: gcc at gcc dot gnu dot org
- Date: Tue, 19 Apr 2005 08:49:52 +0200
- Subject: Re: Reload Issue -- I can't believe we haven't hit this before
- References: <1113890539.803.116.camel@localhost.localdomain>
> So the combination of the TCB merge plus the pending jump threading
> changes apparently has ticked a reload bug which manifests itself with
> the stage1 compiler mis-compiling the stage2 compiler.
>
> [...]
>
> Which faults because the memory location is actually read-only memory.
PR rtl-optimization/15248.
> What's not clear to me is how best to fix this.
>
> We could try to delete all assignments to pseudos which are equivalent
> to MEMs.
>
> We could avoid recording equivalences when the pseudo is set more than
> once.
>
> Other possibilities?
For 3.3 and 3.4, this was "fixed" by not recording memory equivalences that
have the infamous RTX_UNCHANGING_P flag set.
--
Eric Botcazou