swiftlang/swift
Voir sur GitHub[SR-1111] Non-optimized builds should avoid redundant thick_to_objc_metatype conversions
Open
#43 724 ouverte le 30 mars 2016
IRGencompilergood first issueimprovementnon-optimized only
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Description
| Previous ID | SR-1111 |
| Radar | None |
| Original Reporter | @belkadan |
| Type | Improvement |
| Votes | 0 |
| Component/s | Compiler |
| Labels | Improvement, IRGen, NotOptimizedOnly, StarterBug |
| Assignee | None |
| Priority | Medium |
md5: ee5fa37243b2596a51a6125675863696
Issue Description:
In this code:
import Foundation
func test() -> Bool {
let a = RunLoop.current
let b = RunLoop.main
return a === b
}
We're smart enough to avoid emitting two references to the metadata for NSRunLoop, but not smart enough (in -Onone builds) to avoid emitting the conversion to an ObjC Class twice, which involves a branch. We should be able to reuse the value from the first thick_to_objc_metatype conversion.