[llvm-commits] [llvm] r98023 - /llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp

[Jakob Stoklund Olesen]

On Mar 9, 2010, at 9:41 AM, Jakob Stoklund Olesen wrote:

> 
> On Mar 8, 2010, at 5:37 PM, Jakob Stoklund Olesen wrote:
> 
>> 
>> On Mar 8, 2010, at 5:23 PM, Evan Cheng wrote:
>> 
>>> Is 1000 scientific? :-)
>> 
> 
> The coalescer timing formed a perfect parabola with t=4.1s at N=2000. This is not a caching effect - the coalescer is quadratic in the number of function calls!

The attached graph shows the coalescer runtime as a function of the array length in my tiny test function (inlining disabled). The patch kicks in at N=500 and reduces runtime to nothing.

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