[LLVMdev] [PATCH] FoldingSetNodeID: use MurmurHash2 instead of SuperFastHash

Chris Lattner clattner at apple.com
Mon Feb 8 10:31:23 PST 2010

On Feb 7, 2010, at 1:03 PM, Gregory Petrosyan wrote:

> On Sat, Feb 06, 2010 at 04:51:15PM -0800, Chandler Carruth wrote:
>> While I've not reviewed the patch in too much detail, it looks
>> promising. Can you run some end-to-end benchmarks to make sure that
>> cache pressure in the full program or other variables not accounted
>> for in a micro-benchmark don't dominate performance? Specifically the
>> nightly tester includes a number of real programs and machinery to
>> measure total compile time.
> Ok, now with some kinda-hard numbers!

Hi Gregory,

These numbers are so noisy, that they aren't particularly useful.   
Could you try instrumenting foldingset to keep track track of the #  
collisions and # hash table resizes and compare those?  They should be  
much more stable and still correlate directly to performance.


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