Bug 230908

Summary: Reduce loop strength on ARM64 too
Product: WebKit Reporter: Justin Michaud <justin_michaud>
Component: New BugsAssignee: Justin Michaud <justin_michaud>
Status: NEW ---    
Severity: Normal CC: ews-watchlist, keith_miller, mark.lam, msaboff, sbarati, tzagallo, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Bug Depends on: 232647    
Bug Blocks:    
Attachments:
Description Flags
Patch
none
Patch ews-feeder: commit-queue-

Description Justin Michaud 2021-09-28 11:57:15 PDT
Reduce loop strength on ARM64 too
Comment 1 Justin Michaud 2021-09-28 12:06:16 PDT
Created attachment 439504 [details]
Patch
Comment 2 Justin Michaud 2021-09-28 12:07:14 PDT
This is WIP, but I wanted to save it here so I don't lose it while testing perf
Comment 3 Justin Michaud 2021-09-28 13:01:22 PDT
A mixed bag so far:

memcpy-wasm-small                  171.2750+-1.6420     !    181.5388+-0.9457        ! definitely 1.0599x slower
memcpy-wasm-large                  438.1443+-14.3229    ^     44.0324+-1.8863        ^ definitely 9.9505x faster
memcpy-wasm-medium                  20.1398+-0.6413     !     22.5029+-0.4836        ! definitely 1.1173x slower
memcpy-typed-loop-speculative     1304.0646+-23.7363        1283.0492+-10.2491         might be 1.0164x faster
memcpy-typed-loop                   59.6541+-0.3893     ?     59.7131+-0.6997        ?
memcpy-wasm                        339.8212+-1.6913     ^     46.7857+-0.6053        ^ definitely 7.2634x faster
memcpy-typed-loop-large          81118.9502+-150.6358      80774.3593+-894.3635      
memcpy-loop                       4919.8907+-68.8522    ?   4960.3104+-48.1172       ?
memcpy-typed-loop-small             76.2613+-1.0061     !     78.2971+-0.7698        ! definitely 1.0267x slower
Comment 4 Justin Michaud 2021-09-29 16:17:52 PDT
Created attachment 439678 [details]
Patch
Comment 5 Radar WebKit Bug Importer 2021-10-05 11:58:22 PDT
<rdar://problem/83897351>