[CloneFunction] Remove check that is no longer necessary

[danilaml]

We do not need to concern ourselves with CGSCC since all remaining CG related updates went away in fa6ea7a as pointed out by @nikic in #87963 (comment).

[llvmbot]

@llvm/pr-subscribers-llvm-transforms

Author: Danila Malyutin (danilaml)

Changes

We do not need to concern ourselves with CGSCC since all remaining CG related updates went away in fa6ea7a as pointed out by @nikic in #87963 (comment).

---

Full diff: https://github.com/llvm/llvm-project/pull/92577.diff

1 Files Affected:

• (modified) llvm/lib/Transforms/Utils/CloneFunction.cpp (-7)

diff --git a/llvm/lib/Transforms/Utils/CloneFunction.cpp b/llvm/lib/Transforms/Utils/CloneFunction.cpp
index 981183682b8bf..1fef8bc461211 100644
--- a/llvm/lib/Transforms/Utils/CloneFunction.cpp
+++ b/llvm/lib/Transforms/Utils/CloneFunction.cpp
@@ -825,13 +825,6 @@ void llvm::CloneAndPruneIntoFromInst(Function *NewFunc, const Function *OldFunc,
       if (!NewI)
         continue;
 
-      // Skip over non-intrinsic callsites, we don't want to remove any nodes
-      // from the CGSCC.
-      CallBase *CB = dyn_cast<CallBase>(NewI);
-      if (CB && CB->getCalledFunction() &&
-          !CB->getCalledFunction()->isIntrinsic())
-        continue;
-
       if (Value *V = simplifyInstruction(NewI, DL)) {
         NewI->replaceAllUsesWith(V);
 

[nikic]

Could you please add a test for the additional folding this enables?

[danilaml]

@nikic have some downstream function calls that can be simplified but not constant folded. Will see if I can come up with a test for current main.

[nikic]

It looks like InstSimplify only does constant folding for non-intrinsics, so probably the only way to hit this with upstream LLVM is if it's constant folding that involves a loop phi in some way and thus only happens late?

Given that, constructing a test case may be tricky, so I'm fine with landing it as-is.

[danilaml]

@nikic Yeah, wasn't able to come up with the test. Another thing is that upstream simplifyCall currently only handles poison/undef callee (wasn't skipped due to CB->getCalledFunction() check), intrinsics (wasn't skipped by the check) and also attempt to constant fold call (was already done before), but I still think it's good to remove this "dead" code with outdated comment.