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Re: [tree-ssa] Copy propagation [patch]
- From: law at redhat dot com
- To: Eric Christopher <echristo at redhat dot com>
- Cc: Steven Bosscher <s dot bosscher at student dot tudelft dot nl>, Diego Novillo <dnovillo at redhat dot com>, gcc-patches at gcc dot gnu dot org
- Date: Fri, 28 Feb 2003 18:58:45 -0700
- Subject: Re: [tree-ssa] Copy propagation [patch]
- Reply-to: law at redhat dot com
In message <1046482781 dot 1199 dot 22 dot camel at ghostwheel dot ges dot redhat dot com>, Eric Christoph
er writes:
>
>> >Well, one of the advantages that a hashed ssa gives you is the ability
>> >to get GVN for free, but your point still stands. :)
>> Note the stuff isn't really hashed SSA that you find in the SGI
>> compiler or under a different name in Morgan's book (yes, if you look
>> closely they're both basically the same thing).
>
>Yah. I had.
>
>> The stuff I'm talking about does value-numbering, constant and copy prop
>> on the dominator tree while rewriting the function into SSA. The cool thin
>g
>> is the cost is basically a hash table lookup and a little bookkeeping in th
>e
>> hash table as we leave blocks.
>>
>
>Hrm? Pointer to article?
Morgan touches ever-so-briefly on concepts similar to hashed ssa during
the introduction as part of building for formal temporary table during
building of the flow graph.
The dominator opts I've referred to are in a section called "dominator
based optimization" :-)
Jeff