Dan Hecht has posted comments on this change.

Change subject: Use AVX2 operations to speedup Bloom filter insert by 10-50%.
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Patch Set 4:

(1 comment)

http://gerrit.cloudera.org:8080/#/c/3338/4/be/src/util/bloom-filter.h
File be/src/util/bloom-filter.h:

Line 160:   if (CpuInfo::IsSupported(CpuInfo::AVX2)) {
We should standardize on one way to dispatch based on CPUs.  According to this 
page: https://gcc.gnu.org/wiki/FunctionMultiVersioning, GCC also has built in 
support for this if you define two versions of BucketInsert(), one with 
"default" target and one with "avx2" target.  It doesn't sound like it patches 
the code directly, though, so still incurs a runtime cost of dispatching 
(sounds like they are using "jmp *ptr"). 

Have you looked at that to see which way would be better?


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Gerrit-MessageType: comment
Gerrit-Change-Id: I6fef4f6652876f8fd7e3f0e41431702380418c98
Gerrit-PatchSet: 4
Gerrit-Project: Impala
Gerrit-Branch: cdh5-trunk
Gerrit-Owner: Jim Apple <[email protected]>
Gerrit-Reviewer: Dan Hecht <[email protected]>
Gerrit-Reviewer: Jim Apple <[email protected]>
Gerrit-Reviewer: Tim Armstrong <[email protected]>
Gerrit-HasComments: Yes

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