Disable MandatoryCopyPropagation. #41469
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Mandatory copy propagation was primarily a stop-gap until lexcial lifetimes were implemented. It supposedly made variables lifetimes more consistent between -O and -Onone builds. Now that lexical lifetimes are enabled, it is no longer needed for that purpose (and will never satisfactorily meet that goal anyway). Mandatory copy propagation may be enabled again later as a -Onone " optimization. But that requires a more careful audit of the effect on debug information. For now, it should be disabled.
nate-chandler
approved these changes
Feb 19, 2022
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@swift-ci test |
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@swift-ci please clean test macos platform |
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Mandatory copy propagation was primarily a stop-gap until lexcial
lifetimes were implemented. It supposedly made variables lifetimes
more consistent between -O and -Onone builds. Now that lexical
lifetimes are enabled, it is no longer needed for that purpose (and
will never satisfactorily meet that goal anyway).
Mandatory copy propagation may be enabled again later as a -Onone "
optimization. But that requires a more careful audit of the effect on
debug information.
For now, it should be disabled.