Add explicit tail calls to Clight and C#minor #422
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By popular demand. The tail call optimization pass performed later in CompCert will not turn a call into a tail call if the function has stack-allocated data, because this might change the semantics. Having an explicit Stailcall form in Clight makes it possible to force some calls in tail position to be tail calls, deallocating. deallocate stack-allocated data before the call. This is the same reason why we have an Stailcall form in Cminor already.
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I would have thought that ExportClight.ml would also need to be edited, but I don't see that in the list of "files changed." |
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My mistake. Will fix soon. |
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Tentative fix pushed. |
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Ping! Does this PR address the need? |
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Yes, I'm pretty sure it does. I don't have time to test it this month. I recommend merge the P.R. Thank you. |
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By popular demand.
The tail call optimization pass performed later in CompCert will not turn a call into a tail call if the function has stack-allocated data, because this might change the semantics.
Having an explicit Stailcall form in Clight makes it possible to force a call in tail position to be a tail call, deallocating stack-allocated data before the call. This is the same reason why we have an Stailcall form in Cminor already.
Cc: @andrew-appel