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[MIRVRegNamer] Experimental MachineInstr stable hashing (Fowler-Noll-Vo)

Authored by plotfi on Sep 3 2020, 12:38 PM.

Description

[MIRVRegNamer] Experimental MachineInstr stable hashing (Fowler-Noll-Vo)

This hashing scheme has been useful out of tree, and I want to start
experimenting with it. Specifically I want to experiment on the
MIRVRegNamer, MIRCanononicalizer, and eventually the MachineOutliner.

This diff is a first step, that optionally brings stable hashing to the
MIRVRegNamer (and as a result, the MIRCanonicalizer). We've tested this
hashing scheme on a lot of MachineOperand types that llvm::hash_value
can not handle in a stable manner.

This stable hashing was also the basis for

"Global Machine Outliner for ThinLTO" in EuroLLVM 2020

http://llvm.org/devmtg/2020-04/talks.html#TechTalk_58

Credits: Kyungwoo Lee, Nikolai Tillmann

Differential Revision: https://reviews.llvm.org/D86952

Details

Committed
Puyan Lotfi <plotfi@fb.com>Sep 3 2020, 1:13 PM
Differential Revision
D86952: [MIRVRegNamer] MachineInstr StableHashing.
Parents
rGc9771391ce05: [NewPM][Lint] Port -lint to NewPM
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