[instcombine] Cleanup foldAllocaCmp slightly [NFC]

Author: preames

llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp

@@ -1006,8 +1006,7 @@ Instruction *InstCombinerImpl::foldGEPICmp(GEPOperator *GEPLHS, Value *RHS,
 }
 
 Instruction *InstCombinerImpl::foldAllocaCmp(ICmpInst &ICI,
-                                             const AllocaInst *Alloca,
-                                             const Value *Other) {
+                                             const AllocaInst *Alloca) {
   assert(ICI.isEquality() && "Cannot fold non-equality comparison.");
 
   // It would be tempting to fold away comparisons between allocas and any
@@ -1076,10 +1075,9 @@ Instruction *InstCombinerImpl::foldAllocaCmp(ICmpInst &ICI,
     }
   }
 
-  Type *CmpTy = CmpInst::makeCmpResultType(Other->getType());
-  return replaceInstUsesWith(
-      ICI,
-      ConstantInt::get(CmpTy, !CmpInst::isTrueWhenEqual(ICI.getPredicate())));
+  auto *Res = ConstantInt::get(ICI.getType(),
+                               !CmpInst::isTrueWhenEqual(ICI.getPredicate()));
+  return replaceInstUsesWith(ICI, Res);
 }
 
 /// Fold "icmp pred (X+C), X".
@@ -6061,10 +6059,10 @@ Instruction *InstCombinerImpl::visitICmpInst(ICmpInst &I) {
   if (Op0->getType()->isPointerTy() && I.isEquality()) {
     assert(Op1->getType()->isPointerTy() && "Comparing pointer with non-pointer?");
     if (auto *Alloca = dyn_cast<AllocaInst>(getUnderlyingObject(Op0)))
-      if (Instruction *New = foldAllocaCmp(I, Alloca, Op1))
+      if (Instruction *New = foldAllocaCmp(I, Alloca))
         return New;
     if (auto *Alloca = dyn_cast<AllocaInst>(getUnderlyingObject(Op1)))
-      if (Instruction *New = foldAllocaCmp(I, Alloca, Op0))
+      if (Instruction *New = foldAllocaCmp(I, Alloca))
         return New;
   }
 

llvm/lib/Transforms/InstCombine/InstCombineInternal.h

@@ -650,8 +650,7 @@ class LLVM_LIBRARY_VISIBILITY InstCombinerImpl final
 
   Instruction *foldGEPICmp(GEPOperator *GEPLHS, Value *RHS,
                            ICmpInst::Predicate Cond, Instruction &I);
-  Instruction *foldAllocaCmp(ICmpInst &ICI, const AllocaInst *Alloca,
-                             const Value *Other);
+  Instruction *foldAllocaCmp(ICmpInst &ICI, const AllocaInst *Alloca);
   Instruction *foldCmpLoadFromIndexedGlobal(LoadInst *LI,
                                             GetElementPtrInst *GEP,
                                             GlobalVariable *GV, CmpInst &ICI,