[CallSite removal][ExecutionEngine] Use CallBase in the Interpreter. NFC

[craig.topper]

Summary

While there use the VAStart/VAEnd/VACopy/IntrinsicInst visitor
methods to avoid custom checking for these cases.

[mtrofin]

lgtm, some nits

llvm/lib/ExecutionEngine/Interpreter/Execution.cpp

1139

"me" -> "Me"?

1164

Can the iterator be capitalized? Since there's an "I", how about ArgI?

llvm/lib/ExecutionEngine/Interpreter/Execution.cpp

 //===-- Execution.cpp - Implement code to simulate the program ------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
if (RetTy && !RetTy->isVoidTy()) {          // Nonvoid return type?
       ExitValue = Result;   // Capture the exit value of the program
     } else {
       memset(&ExitValue.Untyped, 0, sizeof(ExitValue.Untyped));
     }
   } else {
     // If we have a previous stack frame, and we have a previous call,
     // fill in the return value...
     ExecutionContext &CallingSF = ECStack.back();
-    if (Instruction *I = CallingSF.Caller.getInstruction()) {
+    if (CallingSF.Caller) {
       // Save result...
-      if (!CallingSF.Caller.getType()->isVoidTy())
-        SetValue(I, Result, CallingSF);
-      if (InvokeInst *II = dyn_cast<InvokeInst> (I))
+      if (!CallingSF.Caller->getType()->isVoidTy())
+        SetValue(CallingSF.Caller, Result, CallingSF);
+      if (InvokeInst *II = dyn_cast<InvokeInst>(CallingSF.Caller))
         SwitchToNewBasicBlock (II->getNormalDest (), CallingSF);
-      CallingSF.Caller = CallSite();          // We returned from the call...
+      CallingSF.Caller = nullptr;             // We returned from the call...
     }
   }
 }
 
 void Interpreter::visitReturnInst(ReturnInst &I) {
   ExecutionContext &SF = ECStack.back();
   Type *RetTy = Type::getVoidTy(I.getContext());
   GenericValue Result;
void Interpreter::visitStoreInst(StoreInst &I) {
   if (I.isVolatile() && PrintVolatile)
     dbgs() << "Volatile store: " << I;
 }
 
 //===----------------------------------------------------------------------===//
 //                 Miscellaneous Instruction Implementations
 //===----------------------------------------------------------------------===//
 
-void Interpreter::visitCallSite(CallSite CS) {
+void Interpreter::visitVAStartInst(VAStartInst &I) {
   ExecutionContext &SF = ECStack.back();
-
-  // Check to see if this is an intrinsic function call...
-  Function *F = CS.getCalledFunction();
-  if (F && F->isDeclaration())
-    switch (F->getIntrinsicID()) {
-    case Intrinsic::not_intrinsic:
-      break;
-    case Intrinsic::vastart: { // va_start
-      GenericValue ArgIndex;
-      ArgIndex.UIntPairVal.first = ECStack.size() - 1;
-      ArgIndex.UIntPairVal.second = 0;
-      SetValue(CS.getInstruction(), ArgIndex, SF);
-      return;
-    }
-    case Intrinsic::vaend:    // va_end is a noop for the interpreter
-      return;
-    case Intrinsic::vacopy:   // va_copy: dest = src
-      SetValue(CS.getInstruction(), getOperandValue(*CS.arg_begin(), SF), SF);
-      return;
-    default:
-      // If it is an unknown intrinsic function, use the intrinsic lowering
-      // class to transform it into hopefully tasty LLVM code.
-      //
-      BasicBlock::iterator me(CS.getInstruction());
-      BasicBlock *Parent = CS.getInstruction()->getParent();
-      bool atBegin(Parent->begin() == me);
-      if (!atBegin)
-        --me;
-      IL->LowerIntrinsicCall(cast<CallInst>(CS.getInstruction()));
+  SetValue(&I, ArgIndex, SF);
+
+void Interpreter::visitVAEndInst(VAEndInst &I) {
+  // va_end is a noop for the interpreter
+}
+
+void Interpreter::visitVACopyInst(VACopyInst &I) {
+  ExecutionContext &SF = ECStack.back();
+  SetValue(&I, getOperandValue(*I.arg_begin(), SF), SF);
+}
+
+void Interpreter::visitIntrinsicInst(IntrinsicInst &I) {
+  ExecutionContext &SF = ECStack.back();
+
+  BasicBlock::iterator me(&I);
+  BasicBlock *Parent = I.getParent();
+  IL->LowerIntrinsicCall(&I);
 
-      // Restore the CurInst pointer to the first instruction newly inserted, if
-      // any.
-      if (atBegin) {
-        SF.CurInst = Parent->begin();
-      } else {
-        SF.CurInst = me;
-        ++SF.CurInst;
-      }
-      return;
-    }
 
+void Interpreter::visitCallBase(CallBase &I) {
+  ExecutionContext &SF = ECStack.back();
 
-  SF.Caller = CS;
+  SF.Caller = &I;
   std::vector<GenericValue> ArgVals;
-  const unsigned NumArgs = SF.Caller.arg_size();
+  const unsigned NumArgs = SF.Caller->arg_size();
   ArgVals.reserve(NumArgs);
   uint16_t pNum = 1;
-  for (CallSite::arg_iterator i = SF.Caller.arg_begin(),
-         e = SF.Caller.arg_end(); i != e; ++i, ++pNum) {
+  for (auto i = SF.Caller->arg_begin(), e = SF.Caller->arg_end(); i != e;
+       ++i, ++pNum) {
     Value *V = *i;
     ArgVals.push_back(getOperandValue(V, SF));
   }
 
   // To handle indirect calls, we must get the pointer value from the argument
   // and treat it as a function pointer.
-  GenericValue SRC = getOperandValue(SF.Caller.getCalledValue(), SF);
+  GenericValue SRC = getOperandValue(SF.Caller->getCalledValue(), SF);
   callFunction((Function*)GVTOP(SRC), ArgVals);
 }
 
 // auxiliary function for shift operations
 static unsigned getShiftAmount(uint64_t orgShiftAmount,
                                llvm::APInt valueToShift) {
   unsigned valueWidth = valueToShift.getBitWidth();
   if (orgShiftAmount < (uint64_t)valueWidth)

 //===----------------------------------------------------------------------===//
 //                        Dispatch and Execution Code
 //===----------------------------------------------------------------------===//
 
 //===----------------------------------------------------------------------===//
 // callFunction - Execute the specified function...
 //
 void Interpreter::callFunction(Function *F, ArrayRef<GenericValue> ArgVals) {
-  assert((ECStack.empty() || !ECStack.back().Caller.getInstruction() ||
-          ECStack.back().Caller.arg_size() == ArgVals.size()) &&
+  assert((ECStack.empty() || !ECStack.back().Caller ||
+          ECStack.back().Caller->arg_size() == ArgVals.size()) &&
          "Incorrect number of arguments passed into function call!");
   // Make a new stack frame... and fill it in.
   ECStack.emplace_back();
   ExecutionContext &StackFrame = ECStack.back();
   StackFrame.CurFunction = F;
 
   // Special handling for external functions.
   if (F->isDeclaration()) {

llvm/lib/ExecutionEngine/Interpreter/Interpreter.h

 //===-- Interpreter.h ------------------------------------------*- C++ -*--===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //

 
 // ExecutionContext struct - This struct represents one stack frame currently
 // executing.
 //
 struct ExecutionContext {
   Function             *CurFunction;// The currently executing function
   BasicBlock           *CurBB;      // The currently executing BB
   BasicBlock::iterator  CurInst;    // The next instruction to execute
-  CallSite             Caller;     // Holds the call that called subframes.
+  CallBase             *Caller;     // Holds the call that called subframes.
                                     // NULL if main func or debugger invoked fn
   std::map<Value *, GenericValue> Values; // LLVM values used in this invocation
   std::vector<GenericValue>  VarArgs; // Values passed through an ellipsis
   AllocaHolder Allocas;            // Track memory allocated by alloca
 
   ExecutionContext() : CurFunction(nullptr), CurBB(nullptr), CurInst(nullptr) {}
 };
 
 // Interpreter - This class represents the entirety of the interpreter.
public:
   void visitSIToFPInst(SIToFPInst &I);
   void visitFPToUIInst(FPToUIInst &I);
   void visitFPToSIInst(FPToSIInst &I);
   void visitPtrToIntInst(PtrToIntInst &I);
   void visitIntToPtrInst(IntToPtrInst &I);
   void visitBitCastInst(BitCastInst &I);
   void visitSelectInst(SelectInst &I);
 
-
-  void visitCallSite(CallSite CS);
-  void visitCallInst(CallInst &I) { visitCallSite (CallSite (&I)); }
-  void visitInvokeInst(InvokeInst &I) { visitCallSite (CallSite (&I)); }
+  void visitVAStartInst(VAStartInst &I);
+  void visitVAEndInst(VAEndInst &I);
+  void visitVACopyInst(VACopyInst &I);
+  void visitIntrinsicInst(IntrinsicInst &I);
+  void visitCallBase(CallBase &I);
   void visitUnreachableInst(UnreachableInst &I);
 
   void visitShl(BinaryOperator &I);
   void visitLShr(BinaryOperator &I);
   void visitAShr(BinaryOperator &I);
 
   void visitVAArgInst(VAArgInst &I);
   void visitExtractElementInst(ExtractElementInst &I);