never construct value on stack in new_box_zeroed (#1601) #1604
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On lower opt-levels the compiler might not optimize out the `layout.size() == 0` branch and emits code for the if-body. This will cause a stack allocation for `Self`. Avoid calling new_zeroed() and directly construct the Box from a dangling pointer instead. Co-authored-by: Joshua Liebow-Feeser <[email protected]>
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jswrenn
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Sep 3, 2024
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On lower opt-levels the compiler might not optimize out the
layout.size() == 0branch and emits code for the if-body. This will cause a stack allocation forSelf. Avoid calling new_zeroed() and directly construct the Box from a dangling pointer instead.