llvm::promoteCallWithVTableCmp

This is similar to promoteCallWithIfThenElse except that the condition to promote a virtual call is that VPtr is the same as any of AddressPoints.

Synopsis

Declared in <llvm/Transforms/Utils/CallPromotionUtils.h>

CallBase&
promoteCallWithVTableCmp(
    CallBase& CB,
    Instruction* VPtr,
    Function* Callee,
    ArrayRef<Constant*> AddressPoints,
    MDNode* BranchWeights);

Description

This function is expected to be used on virtual calls (a subset of indirect calls). VPtr is the virtual table address stored in the objects, and AddressPoints contains vtable address points. A vtable address point is a location inside the vtable that's referenced by vpointer in C++ objects.

TODO: sink the address‐calculation instructions of indirect callee to the indirect call fallback after transformation.

Return Value

The promoted direct call placed in the "then" block.

Parameters

Name

Description

Virtual call site to promote conditionally.

VPtr

Virtual table pointer compared against the address points.

Callee

Function to call on the promoted path.

AddressPoints

Vtable address points that identify the promoted type.

BranchWeights

Optional !prof metadata for the new conditional branch.

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