[llvm-commits] [llvm] r122326 - in /llvm/trunk: lib/Analysis/InstructionSimplify.cpp test/Transforms/InstSimplify/ test/Transforms/InstSimplify/2010-12-20-Reassociate.ll test/Transforms/InstSimplify/dg.exp

[Chris Lattner]

On Dec 21, 2010, at 12:49 AM, Duncan Sands wrote:

> Author: baldrick
> Date: Tue Dec 21 02:49:00 2010
> New Revision: 122326
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=122326&view=rev
> Log:
> Add generic simplification of associative operations, generalizing
> a couple of existing transforms.  This fires surprisingly often, for
> example when compiling gcc "(X+(-1))+1->X" fires quite a lot as well
> as various "and" simplifications (usually with a phi node operand).
> Most of the time this doesn't make a real difference since the same
> thing would have been done elsewhere anyway, eg: by instcombine, but
> there are a few places where this results in simplifications that we
> were not doing before.

Nice.  Should the related logic get ripped out of instcombine?  It is probably a little more general, but if it doesn't matter in practice, we should remove it.

-Chris