[Patch]: Fix PR rtl-optimization/50448

[Paolo Bonzini]

On 11/03/2011 10:21 PM, Eric Botcazou wrote:
>> 	PR rtl-optimization/50448
>> >  	* cprop.c (try_replace_reg): Try to simplify SET_SRC given the
>> >  	substitution.
> The whole patch is about SET_DEST though, so I'm a little confused.

Yes, the changelog is wrong indeed.  Registers in a SET_DEST memory are 
uses, so they are like SET_SRC in this context which is why I think the 
patch does belong in try_replace_reg.  Georg, what do you think of a 
changelog like this:

   Also try to replace uses of FROM that appear in SET_DEST.

> And the
> head comment of try_replace_reg reads:
>
> /* Try to replace all non-SET_DEST occurrences of FROM in INSN with TO.
>     Returns nonzero is successful.  */

I agree; like above, the patch should also change the head comment like 
this:

/* Try to replace all uses of FROM in INSN with TO.  Returns
    nonzero is successful.  */

Paolo