[llvm][NFC][CallSite] Remove CallSite from a few trivial locations

[mtrofin]

Summary

Implementation details and internal (to module) APIs.

[craig.topper]

llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp

729–730

This comment isn't relevant to this code. There used to be some code here that modified cpySrc/cpyDest. It was removed and the comment was orphaned.

I don't think we need CB. Can't we just use C directly, its already a CallInst.

[mtrofin]

feedback

[craig.topper]

LGTM

llvm/lib/Transforms/IPO/GlobalOpt.cpp

 #include "llvm/Analysis/BlockFrequencyInfo.h"
 #include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/MemoryBuiltins.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/CallSite.h"
 #include "llvm/IR/CallingConv.h"
 #include "llvm/IR/Constant.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
for (BasicBlock &BB : *F)
     if (BB.getTerminatingMustTailCall())
       return false;
 
   return true;
 }
 
 /// Return true if the block containing the call site has a BlockFrequency of
 /// less than ColdCCRelFreq% of the entry block.
-static bool isColdCallSite(CallSite CS, BlockFrequencyInfo &CallerBFI) {
+static bool isColdCallSite(CallBase &CB, BlockFrequencyInfo &CallerBFI) {
   const BranchProbability ColdProb(ColdCCRelFreq, 100);
-  auto CallSiteBB = CS.getInstruction()->getParent();
+  auto *CallSiteBB = CB.getParent();
   auto CallSiteFreq = CallerBFI.getBlockFreq(CallSiteBB);
   auto CallerEntryFreq =
-      CallerBFI.getBlockFreq(&(CS.getCaller()->getEntryBlock()));
+      CallerBFI.getBlockFreq(&(CB.getCaller()->getEntryBlock()));
   return CallSiteFreq < CallerEntryFreq * ColdProb;
 }
 
 // This function checks if the input function F is cold at all call sites. It
 // also looks each call site's containing function, returning false if the
 // caller function contains other non cold calls. The input vector AllCallsCold
 // contains a list of functions that only have call sites in cold blocks.
 static bool
 isValidCandidateForColdCC(Function &F,
                           function_ref<BlockFrequencyInfo &(Function &)> GetBFI,
                           const std::vector<Function *> &AllCallsCold) {
 
   if (F.user_empty())
     return false;
 
   for (User *U : F.users()) {
     if (isa<BlockAddress>(U))
       continue;
 
-    CallSite CS(cast<Instruction>(U));
-    Function *CallerFunc = CS.getInstruction()->getParent()->getParent();
+    CallBase &CB = cast<CallBase>(*U);
+    Function *CallerFunc = CB.getParent()->getParent();
     BlockFrequencyInfo &CallerBFI = GetBFI(*CallerFunc);
-    if (!isColdCallSite(CS, CallerBFI))
+    if (!isColdCallSite(CB, CallerBFI))
       return false;
     auto It = std::find(AllCallsCold.begin(), AllCallsCold.end(), CallerFunc);
     if (It == AllCallsCold.end())
       return false;
   }
   return true;
 }
 

 // and checks that all call sites are in cold blocks and are allowed to use the
 // coldcc calling convention.
 static bool
 hasOnlyColdCalls(Function &F,
                  function_ref<BlockFrequencyInfo &(Function &)> GetBFI) {
   for (BasicBlock &BB : F) {
     for (Instruction &I : BB) {
       if (CallInst *CI = dyn_cast<CallInst>(&I)) {
-        CallSite CS(cast<Instruction>(CI));
         // Skip over isline asm instructions since they aren't function calls.
         if (CI->isInlineAsm())
           continue;
         Function *CalledFn = CI->getCalledFunction();
         if (!CalledFn)
           return false;
         if (!CalledFn->hasLocalLinkage())
           return false;
         // Skip over instrinsics since they won't remain as function calls.
         if (CalledFn->getIntrinsicID() != Intrinsic::not_intrinsic)
           continue;
         // Check if it's valid to use coldcc calling convention.
         if (!hasChangeableCC(CalledFn) || CalledFn->isVarArg() ||
             CalledFn->hasAddressTaken())
           return false;
         BlockFrequencyInfo &CallerBFI = GetBFI(F);
-        if (!isColdCallSite(CS, CallerBFI))
+        if (!isColdCallSite(*CI, CallerBFI))
           return false;
       }
     }
   }
   return true;
 }
 
 static bool

llvm/lib/Transforms/IPO/IPConstantPropagation.cpp

 // them.  The existing dead argument elimination pass should be run after this
 // to clean up the mess.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/ValueTracking.h"
-#include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Module.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/Pass.h"
 #include "llvm/Transforms/IPO.h"
 using namespace llvm;
 
if (ReturnInst *RI = dyn_cast<ReturnInst>(BB.getTerminator())) {
       }
     }
 
   // If we got here, the function returns at least one constant value.  Loop
   // over all users, replacing any uses of the return value with the returned
   // constant.
   bool MadeChange = false;
   for (Use &U : F.uses()) {
-    CallSite CS(U.getUser());
-    Instruction* Call = CS.getInstruction();
+    CallBase *CB = dyn_cast<CallBase>(U.getUser());
 
     // Not a call instruction or a call instruction that's not calling F
     // directly?
-    if (!Call || !CS.isCallee(&U))
+    if (!CB || !CB->isCallee(&U))
       continue;
 
     // Call result not used?
-    if (Call->use_empty())
+    if (CB->use_empty())
       continue;
 
     MadeChange = true;
 
     if (!STy) {
       Value* New = RetVals[0];
       if (Argument *A = dyn_cast<Argument>(New))
         // Was an argument returned? Then find the corresponding argument in
         // the call instruction and use that.
-        New = CS.getArgument(A->getArgNo());
-      Call->replaceAllUsesWith(New);
+        New = CB->getArgOperand(A->getArgNo());
+      CB->replaceAllUsesWith(New);
       continue;
     }
 
-    for (auto I = Call->user_begin(), E = Call->user_end(); I != E;) {
+    for (auto I = CB->user_begin(), E = CB->user_end(); I != E;) {
       Instruction *Ins = cast<Instruction>(*I);
 
       // Increment now, so we can remove the use
       ++I;
 
       // Find the index of the retval to replace with
       int index = -1;
       if (ExtractValueInst *EV = dyn_cast<ExtractValueInst>(Ins))
         if (EV->getNumIndices() == 1)
           index = *EV->idx_begin();
 
       // If this use uses a specific return value, and we have a replacement,
       // replace it.
       if (index != -1) {
         Value *New = RetVals[index];
         if (New) {
           if (Argument *A = dyn_cast<Argument>(New))
             // Was an argument returned? Then find the corresponding argument in
             // the call instruction and use that.
-            New = CS.getArgument(A->getArgNo());
+            New = CB->getArgOperand(A->getArgNo());
           Ins->replaceAllUsesWith(New);
           Ins->eraseFromParent();
         }
       }
     }
   }
 
   if (MadeChange) ++NumReturnValProped;

llvm/lib/Transforms/IPO/LowerTypeTests.cpp

bool LowerTypeTestsModule::runForTesting(Module &M) {
   }
 
   return Changed;
 }
 
 static bool isDirectCall(Use& U) {
   auto *Usr = dyn_cast<CallInst>(U.getUser());
   if (Usr) {
-    CallSite CS(Usr);
-    if (CS.isCallee(&U))
+    auto *CB = dyn_cast<CallBase>(Usr);
+    if (CB && CB->isCallee(&U))
       return true;
   }
   return false;
 }
 
 void LowerTypeTestsModule::replaceCfiUses(Function *Old, Value *New,
                                           bool IsJumpTableCanonical) {
   SmallSetVector<Constant *, 4> Constants;

llvm/lib/Transforms/IPO/MergeFunctions.cpp

 
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/IR/Argument.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constant.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/DebugLoc.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/GlobalValue.h"
 #include "llvm/IR/IRBuilder.h"

 }
 
 // Replace direct callers of Old with New.
 void MergeFunctions::replaceDirectCallers(Function *Old, Function *New) {
   Constant *BitcastNew = ConstantExpr::getBitCast(New, Old->getType());
   for (auto UI = Old->use_begin(), UE = Old->use_end(); UI != UE;) {
     Use *U = &*UI;
     ++UI;
-    CallSite CS(U->getUser());
-    if (CS && CS.isCallee(U)) {
+    CallBase *CB = dyn_cast<CallBase>(U->getUser());
+    if (CB && CB->isCallee(U)) {
       // Do not copy attributes from the called function to the call-site.
       // Function comparison ensures that the attributes are the same up to
       // type congruences in byval(), in which case we need to keep the byval
       // type of the call-site, not the callee function.
-      remove(CS.getInstruction()->getFunction());
+      remove(CB->getFunction());
       U->set(BitcastNew);
     }
   }
 }
 
 // Helper for writeThunk,
 // Selects proper bitcast operation,
 // but a bit simpler then CastInst::getCastOpcode.

llvm/lib/Transforms/IPO/SyntheticCountsPropagation.cpp

 
 #include "llvm/Transforms/IPO/SyntheticCountsPropagation.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Analysis/BlockFrequencyInfo.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/Analysis/SyntheticCountsUtils.h"
-#include "llvm/IR/CallSite.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
PreservedAnalyses SyntheticCountsPropagation::run(Module &M,
   // Edge includes information about the source. Hence ignore the first
   // parameter.
   auto GetCallSiteProfCount = [&](const CallGraphNode *,
                                   const CallGraphNode::CallRecord &Edge) {
     Optional<Scaled64> Res = None;
     if (!Edge.first)
       return Res;
     assert(isa<Instruction>(Edge.first));
-    CallSite CS(cast<Instruction>(Edge.first));
-    Function *Caller = CS.getCaller();
+    CallBase &CB = cast<CallBase>(*Edge.first);
+    Function *Caller = CB.getCaller();
     auto &BFI = FAM.getResult<BlockFrequencyAnalysis>(*Caller);
 
     // Now compute the callsite count from relative frequency and
     // entry count:
-    BasicBlock *CSBB = CS.getInstruction()->getParent();
+    BasicBlock *CSBB = CB.getParent();
     Scaled64 EntryFreq(BFI.getEntryFreq(), 0);
     Scaled64 BBCount(BFI.getBlockFreq(CSBB).getFrequency(), 0);
     BBCount /= EntryFreq;
     BBCount *= Counts[Caller];
     return Optional<Scaled64>(BBCount);
   };
 
   CallGraph CG(M);

llvm/lib/Transforms/Instrumentation/CGProfile.cpp

 //===-- CGProfile.cpp -----------------------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Instrumentation/CGProfile.h"
 
 #include "llvm/ADT/MapVector.h"
 #include "llvm/Analysis/BlockFrequencyInfo.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
-#include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/MDBuilder.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/ProfileData/InstrProf.h"
 #include "llvm/Transforms/Instrumentation.h"
 
 #include <array>
for (auto &F : M) {
     if (BFI.getEntryFreq() == 0)
       continue;
     TargetTransformInfo &TTI = FAM.getResult<TargetIRAnalysis>(F);
     for (auto &BB : F) {
       Optional<uint64_t> BBCount = BFI.getBlockProfileCount(&BB);
       if (!BBCount)
         continue;
       for (auto &I : BB) {
-        CallSite CS(&I);
-        if (!CS)
+        CallBase *CB = dyn_cast<CallBase>(&I);
+        if (!CB)
           continue;
-        if (CS.isIndirectCall()) {
+        if (CB->isIndirectCall()) {
           InstrProfValueData ValueData[8];
           uint32_t ActualNumValueData;
           uint64_t TotalC;
-          if (!getValueProfDataFromInst(*CS.getInstruction(),
-                                        IPVK_IndirectCallTarget, 8, ValueData,
-                                        ActualNumValueData, TotalC))
+          if (!getValueProfDataFromInst(*CB, IPVK_IndirectCallTarget, 8,
+                                        ValueData, ActualNumValueData, TotalC))
             continue;
           for (const auto &VD :
                ArrayRef<InstrProfValueData>(ValueData, ActualNumValueData)) {
             UpdateCounts(TTI, &F, Symtab.getFunction(VD.Value), VD.Count);
           }
           continue;
         }
-        UpdateCounts(TTI, &F, CS.getCalledFunction(), *BBCount);
+        UpdateCounts(TTI, &F, CB->getCalledFunction(), *BBCount);
       }
     }
   }
 
   addModuleFlags(M, Counts);
 
   return PreservedAnalyses::all();
 }

llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp

 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Instrumentation/SanitizerCoverage.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Analysis/EHPersonalities.h"
 #include "llvm/Analysis/PostDominators.h"
 #include "llvm/IR/CFG.h"
-#include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constant.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/InlineAsm.h"
void ModuleSanitizerCoverage::instrumentFunction(
   const PostDominatorTree *PDT = PDTCallback(F);
   bool IsLeafFunc = true;
 
   for (auto &BB : F) {
     if (shouldInstrumentBlock(F, &BB, DT, PDT, Options))
       BlocksToInstrument.push_back(&BB);
     for (auto &Inst : BB) {
       if (Options.IndirectCalls) {
-        CallSite CS(&Inst);
-        if (CS && !CS.getCalledFunction())
+        CallBase *CB = dyn_cast<CallBase>(&Inst);
+        if (CB && !CB->getCalledFunction())
           IndirCalls.push_back(&Inst);
       }
       if (Options.TraceCmp) {
         if (ICmpInst *CMP = dyn_cast<ICmpInst>(&Inst))
           if (IsInterestingCmp(CMP, DT, Options))
             CmpTraceTargets.push_back(&Inst);
         if (isa<SwitchInst>(&Inst))
           SwitchTraceTargets.push_back(&Inst);

 void ModuleSanitizerCoverage::InjectCoverageForIndirectCalls(
     Function &F, ArrayRef<Instruction *> IndirCalls) {
   if (IndirCalls.empty())
     return;
   assert(Options.TracePC || Options.TracePCGuard ||
          Options.Inline8bitCounters || Options.InlineBoolFlag);
   for (auto I : IndirCalls) {
     IRBuilder<> IRB(I);
-    CallSite CS(I);
-    Value *Callee = CS.getCalledValue();
+    CallBase &CB = cast<CallBase>(*I);
+    Value *Callee = CB.getCalledValue();
     if (isa<InlineAsm>(Callee))
       continue;
     IRB.CreateCall(SanCovTracePCIndir, IRB.CreatePointerCast(Callee, IntptrTy));
   }
 }
 
 // For every switch statement we insert a call:
 // __sanitizer_cov_trace_switch(CondValue,

llvm/lib/Transforms/Instrumentation/ValueProfilePlugins.inc

 public:
   static constexpr InstrProfValueKind Kind = IPVK_IndirectCallTarget;
 
   IndirectCallPromotionPlugin(Function &Fn) : F(Fn) {}
 
   void run(std::vector<CandidateInfo> &Candidates) {
     std::vector<Instruction *> Result = findIndirectCalls(F);
     for (Instruction *I : Result) {
-      Value *Callee = CallSite(I).getCalledValue();
+      Value *Callee = cast<CallBase>(I)->getCalledValue();
       Instruction *InsertPt = I;
       Instruction *AnnotatedInst = I;
       Candidates.emplace_back(CandidateInfo{Callee, InsertPt, AnnotatedInst});
     }
   }
 };
 
 ///----------------------- Registration of the plugins -------------------------
 /// For now, registering a plugin with the ValueProfileCollector is done by
 /// adding the plugin type to the VP_PLUGIN_LIST macro.
 #define VP_PLUGIN_LIST           \
     MemIntrinsicPlugin,          \
     IndirectCallPromotionPlugin

llvm/lib/Transforms/Scalar/LoopUnswitch.cpp

 #include "llvm/Analysis/LoopPass.h"
 #include "llvm/Analysis/MemorySSA.h"
 #include "llvm/Analysis/MemorySSAUpdater.h"
 #include "llvm/Analysis/MustExecute.h"
 #include "llvm/Analysis/ScalarEvolution.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constant.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/InstrTypes.h"
 #include "llvm/IR/Instruction.h"
bool LoopUnswitch::processCurrentLoop() {
   //
   //  - The set of guard intrinsics encountered (these are non terminator
   //    instructions that are also profitable to be unswitched).
 
   SmallVector<IntrinsicInst *, 4> Guards;
 
   for (const auto BB : CurrentLoop->blocks()) {
     for (auto &I : *BB) {
-      auto CS = CallSite(&I);
-      if (!CS) continue;
-      if (CS.isConvergent())
+      auto *CB = dyn_cast<CallBase>(&I);
+      if (!CB)
+        continue;
+      if (CB->isConvergent())
         return false;
       if (auto *II = dyn_cast<InvokeInst>(&I))
         if (!II->getUnwindDest()->canSplitPredecessors())
           return false;
       if (auto *II = dyn_cast<IntrinsicInst>(&I))
         if (II->getIntrinsicID() == Intrinsic::experimental_guard)
           Guards.push_back(II);
     }

llvm/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp

void linearizeExpr(Value *Expr, unsigned Indent, bool ParentReused,
 
       bool Reused = !ReusedExprs.insert(Expr).second;
       if (Reused && !ParentReused)
         write("(reused) ");
 
       if (auto *CI = dyn_cast<CallInst>(I)) {
         writeFnName(CI);
 
-        Ops.append(CallSite(CI).arg_begin(),
-                   CallSite(CI).arg_end() - getNumShapeArgs(CI));
+        Ops.append(CI->arg_begin(), CI->arg_end() - getNumShapeArgs(CI));
       } else if (isa<BitCastInst>(Expr)) {
         // Special case bitcasts, which are used to materialize matrixes from
         // non-matrix ops.
         write("matrix");
         return;
       } else {
         Ops.append(I->value_op_begin(), I->value_op_end());
         write(std::string(I->getOpcodeName()));

llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp

 #include "llvm/Analysis/AssumptionCache.h"
 #include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/Analysis/MemoryDependenceAnalysis.h"
 #include "llvm/Analysis/MemoryLocation.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/IR/Argument.h"
 #include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/GetElementPtrTypeIterator.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/IRBuilder.h"
bool MemCpyOptPass::performCallSlotOptzn(Instruction *cpy, Value *cpyDest,
   // Since moving the memcpy is technically awkward, we additionally check that
   // src only holds uninitialized values at the moment of the call, meaning that
   // the memcpy can be discarded rather than moved.
 
   // Lifetime marks shouldn't be operated on.
   if (Function *F = C->getCalledFunction())
     if (F->isIntrinsic() && F->getIntrinsicID() == Intrinsic::lifetime_start)
       return false;
 
-  // Deliberately get the source and destination with bitcasts stripped away,
-  // because we'll need to do type comparisons based on the underlying type.
-  CallSite CS(C);
-
   // Require that src be an alloca.  This simplifies the reasoning considerably.
   AllocaInst *srcAlloca = dyn_cast<AllocaInst>(cpySrc);
   if (!srcAlloca)
     return false;
 
   ConstantInt *srcArraySize = dyn_cast<ConstantInt>(srcAlloca->getArraySize());
   if (!srcArraySize)
     return false;
 
if (const IntrinsicInst *IT = dyn_cast<IntrinsicInst>(U))
         continue;
 
     if (U != C && U != cpy)
       return false;
   }
 
   // Check that src isn't captured by the called function since the
   // transformation can cause aliasing issues in that case.
-  for (unsigned i = 0, e = CS.arg_size(); i != e; ++i)
-    if (CS.getArgument(i) == cpySrc && !CS.doesNotCapture(i))
+  for (unsigned ArgI = 0, E = C->arg_size(); ArgI != E; ++ArgI)
+    if (C->getArgOperand(ArgI) == cpySrc && !C->doesNotCapture(ArgI))
       return false;
 
   // Since we're changing the parameter to the callsite, we need to make sure
   // that what would be the new parameter dominates the callsite.
   DominatorTree &DT = LookupDomTree();
   if (Instruction *cpyDestInst = dyn_cast<Instruction>(cpyDest))
     if (!DT.dominates(cpyDestInst, C))
       return false;
bool MemCpyOptPass::performCallSlotOptzn(Instruction *cpy, Value *cpyDest,
   if (isModOrRefSet(MR))
     return false;
 
   // We can't create address space casts here because we don't know if they're
   // safe for the target.
   if (cpySrc->getType()->getPointerAddressSpace() !=
       cpyDest->getType()->getPointerAddressSpace())
     return false;
-  for (unsigned i = 0; i < CS.arg_size(); ++i)
-    if (CS.getArgument(i)->stripPointerCasts() == cpySrc &&
+  for (unsigned ArgI = 0; ArgI < C->arg_size(); ++ArgI)
+    if (C->getArgOperand(ArgI)->stripPointerCasts() == cpySrc &&
         cpySrc->getType()->getPointerAddressSpace() !=
-        CS.getArgument(i)->getType()->getPointerAddressSpace())
+            C->getArgOperand(ArgI)->getType()->getPointerAddressSpace())
       return false;
 
   // All the checks have passed, so do the transformation.
   bool changedArgument = false;
-  for (unsigned i = 0; i < CS.arg_size(); ++i)
-    if (CS.getArgument(i)->stripPointerCasts() == cpySrc) {
+  for (unsigned ArgI = 0; ArgI < C->arg_size(); ++ArgI)
+    if (C->getArgOperand(ArgI)->stripPointerCasts() == cpySrc) {
       Value *Dest = cpySrc->getType() == cpyDest->getType() ?  cpyDest
         : CastInst::CreatePointerCast(cpyDest, cpySrc->getType(),
                                       cpyDest->getName(), C);
       changedArgument = true;
-      if (CS.getArgument(i)->getType() == Dest->getType())
-        CS.setArgument(i, Dest);
+      if (C->getArgOperand(ArgI)->getType() == Dest->getType())
+        C->setArgOperand(ArgI, Dest);
       else
-        CS.setArgument(i, CastInst::CreatePointerCast(Dest,
-                          CS.getArgument(i)->getType(), Dest->getName(), C));
+        C->setArgOperand(ArgI, CastInst::CreatePointerCast(
+                                   Dest, C->getArgOperand(ArgI)->getType(),
+                                   Dest->getName(), C));
     }
 
   if (!changedArgument)
     return false;
 
   // If the destination wasn't sufficiently aligned then increase its alignment.
   if (!isDestSufficientlyAligned) {
     assert(isa<AllocaInst>(cpyDest) && "Can only increase alloca alignment!");