[PATCH] D116327: [Coroutines] Enhance symmetric transfer for constant CmpInst

[John McCall via Phabricator via llvm-commits]

rjmccall added inline comments.


================
Comment at: llvm/lib/Transforms/Coroutines/CoroSplit.cpp:1244
+        return false;
+
+      auto *CondConst = dyn_cast<ConstantInt>(CondCmp->getOperand(1));
----------------
I liked the old comment that was here that explained why we bother handling this case.


================
Comment at: llvm/lib/Transforms/Coroutines/CoroSplit.cpp:1247
+      if (!CondConst)
+        return false;
+
----------------
Should we do the same lookup in `ResolvedValues` here?

I would suggest having a general helper that you can put at the top of this function:

```
auto tryResolveConstant = [&](Value *V) -> Constant* {
  auto it = ResolvedValues.find(V));
  if (it != ResolvedValues.end())
   V = it->second;
  return dyn_cast<Constant>(V);
};
```

You don't need to check specifically for `ConstantInt`; LLVM can constant-fold some conditions on other kinds of constants.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D116327/new/

https://reviews.llvm.org/D116327