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[doc] Atomic.add, .subtract: Add note on atomic codegen #78799

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merged 1 commit into from
May 17, 2025
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[doc] Atomic.add, .subtract: Add note on atomic codegen #78799

merged 1 commit into from
May 17, 2025

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lorentey
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Add this note to the doc string of Atomic.add and Atomic.subtract, highlighting a subtle aspect that tends to surprise folks who're porting code from C/C++:

The need to check for overflow means that this operation is typically compiled into a compare-exchange loop. For use cases that require a direct atomic addition, see the wrappingAdd operation: it avoids the loop, but in exchange it allows silent wraps on overflow.

@lorentey lorentey requested a review from Azoy January 22, 2025 00:02
@lorentey lorentey requested a review from a team as a code owner January 22, 2025 00:02
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@swift-ci test

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@swift-ci smoke test linux platform

@lorentey lorentey marked this pull request as draft January 23, 2025 17:49
@lorentey lorentey marked this pull request as ready for review February 1, 2025 02:15
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lorentey commented Feb 1, 2025

@swift-ci smoke test

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@swift-ci test linux platform

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@swift-ci test linux platform

@lorentey lorentey merged commit 02adf95 into swiftlang:main May 17, 2025
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@lorentey lorentey deleted the note-cas-loops branch May 17, 2025 02:05
hamishknight added a commit to hamishknight/swift that referenced this pull request May 22, 2025
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Revert "Merge pull request swiftlang#78799 from lorentey/note-cas-loops"
89546c3 
This reverts commit 02adf95.
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@glessard glessard glessard approved these changes

@stephentyrone stephentyrone stephentyrone approved these changes

@Azoy Azoy Azoy approved these changes

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