Opened 3 years ago

Last modified 2 years ago

#12412 new bug

SIMD things introduce a metric ton of known key things

Reported by: bgamari Owned by:
Priority: low Milestone:
Component: Compiler Version: 8.0.1
Keywords: SIMD Cc:
Operating System: Unknown/Multiple Architecture: Unknown/Multiple
Type of failure: Compile-time performance bug Test Case:
Blocked By: Blocking:
Related Tickets: Differential Rev(s):
Wiki Page:

Description

In #12357 we were looking at reducing the number of entries in the knownKeyNames. This has the potential to improve compiler performance since this set of things is always present in the original name cache, which is often referred to.

#12357 reduced the number of elements in knownKeyNames from 2017 to 1834. Not a bad improvement. That being said, the SIMD operations introduce nearly four times that number. These include things like readWord64OffAddrAsWord64X2#, indexInt16OffAddrAsInt16X16#, and remInt16X16#. All in all these operations constitute nearly a third of the known key names.

I'm not really sure what can be done about this, but I thought it should be noted.

Change History (3)

comment:1 Changed 3 years ago by simonpj

As far as I know, nothing in #12357 suggested that the size of the knownKeyNames had the slightest impact on performance. I'm very un-bothered by the number of knownKeyNames until I see evidence that it has some impact.

Why shoudl we care?

comment:2 Changed 3 years ago by bgamari

As far as I know, nothing in #12357 suggested that the size of the knownKeyNames had the slightest impact on performance.

It's not clear that we should. I merely opened this ticket so I had someplace to write the answer when I find out whether this is something worth worrying about, otherwise I would have surely forgotten.

comment:3 Changed 2 years ago by bgamari

Keywords: SIMD added
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