[6.2] [IRGen] Correctly sext instead of zext for negative integer types #84749

Azoy · 2025-10-07T21:30:07Z

Explanation: Resolves a problem where IRGen was using zext to get the static value of a compile time integer generic. This caused issues with negative integer generics incorrectly being reported as somewhat random values instead of their desired value. Use sext instead.
Risk: Low. Only affects debugs builds (as far as I'm aware) and negative integer generics should be rare still.
Original PR: [IRGen] Correctly sext instead of zext for negative integer types #84655
Reviewed by: @slavapestov and @rjmccall
Resolves: rdar://162147174
Tests: Added a test exercising the exact failure described from the forum post that was failing.

[IRGen] Correctly sext instead of zext for negative integer types

Azoy · 2025-10-07T21:30:15Z

Merge pull request swiftlang#84655 from Azoy/negative-nancy

fbf07e7

[IRGen] Correctly sext instead of zext for negative integer types

Azoy requested a review from a team as a code owner October 7, 2025 21:30

Azoy added 🍒 release cherry pick Flag: Release branch cherry picks swift 6.2 labels Oct 7, 2025

stephentyrone approved these changes Oct 7, 2025

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Azoy merged commit 2a18def into swiftlang:release/6.2 Oct 8, 2025
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Azoy deleted the 62-sext-instead-of-zext branch October 8, 2025 15:03

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