clean up no longer needed code, we can use constantexpr bitcasts for more things in SimplifyStructRegSignatures

Author: kripken

lib/Target/JSBackend/NaCl/SimplifyStructRegSignatures.cpp

@@ -126,7 +126,6 @@ class SimplifyStructRegSignatures : public ModulePass {
   DenseSet<Function *> FunctionsToDelete;
   SetVector<CallInst *> CallsToPatch;
   SetVector<InvokeInst *> InvokesToPatch;
-  SetVector<BitCastInst *> BitCastsToPatch;
   DenseMap<Function *, Function *> FunctionMap;
 
   struct FunctionAddressing {
@@ -437,10 +436,6 @@ void SimplifyStructRegSignatures::scheduleInstructionsForCleanup(
         CallsToPatch.insert(Call);
       } else if (InvokeInst *Invoke = dyn_cast<InvokeInst>(&IIter)) {
         InvokesToPatch.insert(Invoke);
-      } else if (BitCastInst *BitCast = dyn_cast<BitCastInst>(&IIter)) {
-        if (isa<Function>(BitCast->getOperand(0))) {
-          BitCastsToPatch.insert(BitCast);
-        }
       }
     }
   }
@@ -542,16 +537,6 @@ bool SimplifyStructRegSignatures::runOnModule(Module &M) {
     fixCallSite(Ctx, InvokeToFix, PreferredAlignment);
   }
 
-  // BitCasts of a function we are modifying must be corrected
-  for (auto &BitCastToFix : BitCastsToPatch) {
-    auto *Old = cast<Function>(BitCastToFix->getOperand(0));
-    if (FunctionMap.find(Old) != FunctionMap.end()) {
-      auto *New = FunctionMap[Old];
-      IRBuilder<> Builder(BitCastToFix);
-      BitCastToFix->setOperand(0, Builder.CreateBitCast(New, Old->getType(), "bitcastfixcast"));
-    }
-  }
-
   // Update taking of a function's address from a parameter
   for (auto &Addressing : FunctionAddressings) {
     Value *Temp = Addressing.Temp;