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Re: PATCH - [tree-ssa] regrouping of expression tree for single multiply add.


In message <1080008847.31835.196.camel@localhost.localdomain>, Diego Novillo wr
ites:
 >On Mon, 2004-03-22 at 21:25, Fariborz Jahanian wrote:
 >
 >> tree-ssa because it is an 'improvement' patch and I believe mainline is
 >> frozen for improvement patches.
 >> 
 >On the contrary.  It is tree-ssa the frozen one.  mainline is in
 >stage1.  If this goes in mainline, tree-ssa will inherit it at the next
 >merge.
 >
 >> OK for tree-ssa?
 >> 
 >No.  Try mainline.
And I think there's an excellent argument against this kind of transformation
for the mainline as well, at least for FP types.

This kind of transformation makes sense for integers though :-)  THere's
some mips targets that have integer madd and several targets now have
> 1 integer multiply pipeline.  Thus stuff like

a * b * c * d  which is implemented as (((a * b) * c) * d) can be
profitably turned into (a * b) * (c * d).

jeff









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