Issue #12599 has been updated by Noah Gibbs.
Subject changed from For CLang, increase inline-threshold to get 7% speedup of optcarrot to For CLang, increase inline-threshold to get 7%-10% speedup of optcarrot
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Bug #12599: For CLang, increase inline-threshold to get 7%-10% speedup of optcarrot
https://bugs.ruby-lang.org/issues/12599#change-59957
* Author: Noah Gibbs
* Status: Open
* Priority: Normal
* Assignee:
* ruby -v: 2.4.0dev
* Backport: 2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: UNKNOWN
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Here's a patch to set -inline-threshold where it's supported -- it's only for CLang, so I think this is mostly on Mac OS.
Clang's default inline threshold complexity is 225 (see "https://groups.google.com/forum/#!topic/llvm-dev/GpU79q9JzJI"). By turning it up to 5000, the Ruby binary's size goes from about 3MB to 6MB, but there's an overall speedup of the optcarrot benchmark of about 7%.
Here are roughly the speedups I found, using 500+ runs of the optcarrot benchmark for each check:
Threshold: Binary size: Speedup on optcarrot:
5000 6MB 7%
2500 5.5MB 6%
1800 4.8MB 5%
1000 4.4MB 5% (hard to measure diff between 1000 and 1800)
There doesn't seem to be any increase in dynamic memory use - this is only inlining the C code compiled by CLang/LLVM, not changing any Ruby data structures at runtime, so the memory cost seems to only be paid once.
For a desktop Mac in particular, it seems like using 3MB extra for a 7% speedup is a really good deal.
---Files--------------------------------
inline-threshold.patch (1.03 KB)
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