[PATCH] D89249: [SimplifyLibCalls] Preserve tail call indicator

[Eli Friedman via Phabricator via llvm-commits]

efriedma added inline comments.


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Comment at: llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp:1741
+    return replaceInstUsesWith(*CI, With);
   }
 
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xbolva00 wrote:
> jdoerfert wrote:
> > Can `omptimizeCall` ever break the tail requirements, e.g., create an alloca and pass it?
> I dont think so. @efriedma , what do you think?
> 
> 
I don't like this approach. I mean, I get the motivation, but I'm not sure this is the right way to address it.  Three issues:

1. Even if we don't break the "tail" requirements right now, it's likely if someone did introduce a way, they wouldn't notice this code (which isn't even in the same file).
2. A lot of combines create calls, but return some other value.
3. For the floating-point routines, we probably want to add "tail" unconditionally.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D89249/new/

https://reviews.llvm.org/D89249