tapir compiler does not terminate

[wheatman]

After manually in-lining a single function inside of a cilk_for loop the compiler no longer terminates.
The code can be found here https://github.com/wheatman/extended-csr/tree/compilier-spin
If you change OFM.cpp: 1615 - 1660 to add_edge_update_fast
Which is the same thing just in its own function with a no inline attribute then the compiler will terminate with correct results.

[wsmoses]

Note this is not an issue on master, but rather with WIP-taskinfo @neboat assigning to you.

[neboat]

I think I've found the problem. On line 1638 of OFM.cpp, the code is performing a return in the body of a cilk_for loop. Such code is illegal — you can't return from the body of a cilk_for loop — but the front end doesn't currently report that this statement as illegal.

I think we've seen this error arise in other contexts, and it's definitely something we should fix.

[wheatman]

That does seem to be it, when I change the code to remove that,
By simply moving the rest of the function into an else and getting rid of the return statement the code compiles and is correct.

[neboat]

Glad to hear it.

On my end I'm adding some checks in Tapir-Clang to detect return and break statements in cilk_for loops and to throw compiler errors when such statements are detected. We probably want more front-end checks as well, but these two should take care of several problems.

[neboat]

The latest version of the WIP-csi-tapir-exceptions branch of Tapir-Clang addresses the issue of return and break statements in cilk_for loops, so I'm closing this issue.