[llvm] 061bb65 - [ConstantFold] Remove typed pointer specific folds (NFC)

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2023-07-12T15:20:29+02:00
New Revision: 061bb65f7463e84be359b2ded0db309c018f9121

URL: https://github.com/llvm/llvm-project/commit/061bb65f7463e84be359b2ded0db309c018f9121
DIFF: https://github.com/llvm/llvm-project/commit/061bb65f7463e84be359b2ded0db309c018f9121.diff

LOG: [ConstantFold] Remove typed pointer specific folds (NFC)

Added: 
    

Modified: 
    llvm/lib/IR/ConstantFold.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/IR/ConstantFold.cpp b/llvm/lib/IR/ConstantFold.cpp
index fda8bc11bffaa0..20e2882837d13d 100644
--- a/llvm/lib/IR/ConstantFold.cpp
+++ b/llvm/lib/IR/ConstantFold.cpp
@@ -111,29 +111,6 @@ static Constant *FoldBitCast(Constant *V, Type *DestTy) {
   if (SrcTy == DestTy)
     return V; // no-op cast
 
-  // Check to see if we are casting a pointer to an aggregate to a pointer to
-  // the first element.  If so, return the appropriate GEP instruction.
-  if (PointerType *PTy = dyn_cast<PointerType>(V->getType()))
-    if (PointerType *DPTy = dyn_cast<PointerType>(DestTy))
-      if (PTy->getAddressSpace() == DPTy->getAddressSpace() &&
-          !PTy->isOpaque() && !DPTy->isOpaque() &&
-          PTy->getNonOpaquePointerElementType()->isSized()) {
-        SmallVector<Value*, 8> IdxList;
-        Value *Zero =
-          Constant::getNullValue(Type::getInt32Ty(DPTy->getContext()));
-        IdxList.push_back(Zero);
-        Type *ElTy = PTy->getNonOpaquePointerElementType();
-        while (ElTy && ElTy != DPTy->getNonOpaquePointerElementType()) {
-          ElTy = GetElementPtrInst::getTypeAtIndex(ElTy, (uint64_t)0);
-          IdxList.push_back(Zero);
-        }
-
-        if (ElTy == DPTy->getNonOpaquePointerElementType())
-          // This GEP is inbounds because all indices are zero.
-          return ConstantExpr::getInBoundsGetElementPtr(
-              PTy->getNonOpaquePointerElementType(), V, IdxList);
-      }
-
   // Handle casts from one vector constant to another.  We know that the src
   // and dest type have the same size (otherwise its an illegal cast).
   if (VectorType *DestPTy = dyn_cast<VectorType>(DestTy)) {
@@ -2033,11 +2010,6 @@ Constant *llvm::ConstantFoldGetElementPtr(Type *PointeeTy, Constant *C,
     return InBounds ? PoisonValue::get(GEPTy) : UndefValue::get(GEPTy);
 
   auto IsNoOp = [&]() {
-    // For non-opaque pointers having multiple indices will change the result
-    // type of the GEP.
-    if (!C->getType()->getScalarType()->isOpaquePointerTy() && Idxs.size() != 1)
-      return false;
-
     // Avoid losing inrange information.
     if (InRangeIndex)
       return false;
@@ -2086,41 +2058,11 @@ Constant *llvm::ConstantFoldGetElementPtr(Type *PointeeTy, Constant *C,
     }
   }
 
-  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
+  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
     if (auto *GEP = dyn_cast<GEPOperator>(CE))
       if (Constant *C = foldGEPOfGEP(GEP, PointeeTy, InBounds, Idxs))
         return C;
 
-    // Attempt to fold casts to the same type away.  For example, folding:
-    //
-    //   i32* getelementptr ([2 x i32]* bitcast ([3 x i32]* %X to [2 x i32]*),
-    //                       i64 0, i64 0)
-    // into:
-    //
-    //   i32* getelementptr ([3 x i32]* %X, i64 0, i64 0)
-    //
-    // Don't fold if the cast is changing address spaces.
-    Constant *Idx0 = cast<Constant>(Idxs[0]);
-    if (CE->isCast() && Idxs.size() > 1 && Idx0->isNullValue()) {
-      PointerType *SrcPtrTy =
-        dyn_cast<PointerType>(CE->getOperand(0)->getType());
-      PointerType *DstPtrTy = dyn_cast<PointerType>(CE->getType());
-      if (SrcPtrTy && DstPtrTy && !SrcPtrTy->isOpaque() &&
-          !DstPtrTy->isOpaque()) {
-        ArrayType *SrcArrayTy =
-          dyn_cast<ArrayType>(SrcPtrTy->getNonOpaquePointerElementType());
-        ArrayType *DstArrayTy =
-          dyn_cast<ArrayType>(DstPtrTy->getNonOpaquePointerElementType());
-        if (SrcArrayTy && DstArrayTy
-            && SrcArrayTy->getElementType() == DstArrayTy->getElementType()
-            && SrcPtrTy->getAddressSpace() == DstPtrTy->getAddressSpace())
-          return ConstantExpr::getGetElementPtr(SrcArrayTy,
-                                                (Constant *)CE->getOperand(0),
-                                                Idxs, InBounds, InRangeIndex);
-      }
-    }
-  }
-
   // Check to see if any array indices are not within the corresponding
   // notional array or vector bounds. If so, try to determine if they can be
   // factored out into preceding dimensions.