[PATCH] D78259: [TailCallElim] Add handling of readonly functions

[Layton Kifer via Phabricator via llvm-commits]

laytonio marked 2 inline comments as done.
laytonio added inline comments.


================
Comment at: llvm/lib/Transforms/Scalar/TailRecursionElimination.cpp:391
       if (SI->getCondition() == V)
         return SI->getDefaultDest() != RI->getParent();
 
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efriedma wrote:
> While you're in this area, the following currently crashes `opt -tailcallelim`:
> 
> ```
> define i32 @f() local_unnamed_addr {
> entry:
>   %call = call i32 @g()
>   switch i32 %call, label %sw.default [
>     i32 1, label %cleanup
>     i32 5, label %cleanup
>     i32 7, label %cleanup
>   ]
> 
> sw.default:
>   %call1 = call i32 @f()
>   %add = add nsw i32 %call1, 1
>   br label %cleanup
> 
> cleanup:
>   %retval.0 = phi i32 [ %add, %sw.default ], [ %call, %entry ], [ %call, %entry ], [ %call, %entry ]
>   ret i32 %retval.0
> }
> 
> declare i32 @g()
> ```
> 
> Please take a look, since it seems related to what you're doing.
I created a separate diff for this fix. https://reviews.llvm.org/D78765 


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https://reviews.llvm.org/D78259