[5.9] StackPromotion: fix a crash due to a problem in liferange evaluation #67391
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The analysis to check if an alloc_ref outlives it's "inner" liferange had a bug which resulted in a crash in the StackPromotion pass rdar://112275272
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@swift-ci test |
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We're getting close to 5.9 and I don't think this is critical enough. Let's hold for later. |
tbkka
approved these changes
Jul 26, 2023
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Explanation: The analysis to check if an alloc_ref outlives its "inner" liferange had a bug which resulted in a crash in the StackPromotion pass. It is very rare that this bug shows up and I only found it by coincidence. Still, it makes sense to fix it in 5.9 because the risk is very low.
Issue: rdar://112275272
Risk: Very low. It's a small change which makes the optimization more conservative.
Testing: With a regression test
Reviewer: @atrick
Main branch PR: StackPromotion: fix a crash due to a problem in liferange evaluation #67331