[llvm-commits] [llvm] r122819 - /llvm/trunk/lib/Transforms/Scalar/GVN.cpp

[Owen Anderson]

On Jan 4, 2011, at 1:29 PM, Chris Lattner wrote:

> 
> On Jan 4, 2011, at 10:54 AM, Owen Anderson wrote:
> 
>> Author: resistor
>> Date: Tue Jan  4 12:54:18 2011
>> New Revision: 122819
>> 
>> URL: http://llvm.org/viewvc/llvm-project?rev=122819&view=rev
>> Log:
>> Branch instructions don't produce values, so there's no need to generate a value number for them.  This
>> avoids adding them to the various value numbering tables, resulting in a minor (~3%) speedup for GVN
>> on 40.gcc.
> 
> Is there a way to handle "everything that returns void" in one place?  Stores are pretty common as well.
> 
> -Chris

I actually experimented with adding a check for stores to do the same thing when I was writing this patch, but it made absolutely no difference in GVN's runtime.

--Owen
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