ctable: fix power-of-2 issue #1360
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LuaJIT dislikes pointer subtractions when the size of the pointed-to objects is not a power of two, which leads to trace aborts. ctable suffers from this problem. The patch pads the cdata type used as entry for the table to the next power of two. We also disable tail-call optimization for functions that end with a call to a built-in, which also causes trace aborts in certain cases.
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Making this optional is probably not a good idea. |
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I have brought this up in issue #1207, which is still open. I propose this fix at least as an interim solution until RaptorJIT lands (provided it will contain the fix proposed by @lukego).
Removal of two tail-call optimizations is also part of this PR. I found that this reduces trace aborts in my ipfix app some time ago. I'm not sure if we have converged on a common strategy to deal with this sort of problem, so this could be debatable.