[AMDGPU] Remove return nullopt

Author: harrisonGPU

llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp

@@ -275,56 +275,61 @@ simplifyAMDGCNImageIntrinsic(const GCNSubtarget *ST,
       // an ExtractElementInst immediately followed by an FPTrunc to half.
       SmallVector<std::pair<ExtractElementInst *, FPTruncInst *>, 4>
           ExtractTruncPairs;
+      bool AllHalfExtracts = true;
 
       for (User *U : II.users()) {
         auto *Ext = dyn_cast<ExtractElementInst>(U);
-        if (!Ext || !Ext->hasOneUse())
-          return std::nullopt;
+        if (!Ext || !Ext->hasOneUse()) {
+          AllHalfExtracts = false;
+          break;
+        }
 
         auto *Tr = dyn_cast<FPTruncInst>(*Ext->user_begin());
-        if (!Tr || !Tr->getType()->isHalfTy())
-          return std::nullopt;
+        if (!Tr || !Tr->getType()->isHalfTy()) {
+          AllHalfExtracts = false;
+          break;
+        }
 
         ExtractTruncPairs.emplace_back(Ext, Tr);
       }
 
-      if (ExtractTruncPairs.empty())
-        return std::nullopt;
+      if (!ExtractTruncPairs.empty() && AllHalfExtracts) {
+        auto *VecTy = cast<VectorType>(II.getType());
+        Type *HalfVecTy =
+            VecTy->getWithNewType(Type::getHalfTy(II.getContext()));
 
-      auto *VecTy = cast<VectorType>(II.getType());
-      Type *HalfVecTy = VecTy->getWithNewType(Type::getHalfTy(II.getContext()));
+        // Obtain the original image sample intrinsic's signature
+        // and replace its return type with the half-vector for D16 folding
+        SmallVector<Type *, 8> SigTys;
+        Intrinsic::getIntrinsicSignature(II.getCalledFunction(), SigTys);
+        SigTys[0] = HalfVecTy;
 
-      // Obtain the original image sample intrinsic's signature
-      // and replace its return type with the half-vector for D16 folding
-      SmallVector<Type *, 8> SigTys;
-      Intrinsic::getIntrinsicSignature(II.getCalledFunction(), SigTys);
-      SigTys[0] = HalfVecTy;
+        Module *M = II.getModule();
+        Function *HalfDecl =
+            Intrinsic::getOrInsertDeclaration(M, ImageDimIntr->Intr, SigTys);
 
-      Module *M = II.getModule();
-      Function *HalfDecl =
-          Intrinsic::getOrInsertDeclaration(M, ImageDimIntr->Intr, SigTys);
+        II.mutateType(HalfVecTy);
+        II.setCalledFunction(HalfDecl);
 
-      II.mutateType(HalfVecTy);
-      II.setCalledFunction(HalfDecl);
+        IRBuilder<> Builder(II.getContext());
+        for (auto &[Ext, Tr] : ExtractTruncPairs) {
+          Value *Idx = Ext->getIndexOperand();
 
-      IRBuilder<> Builder(II.getContext());
-      for (auto &[Ext, Tr] : ExtractTruncPairs) {
-        Value *Idx = Ext->getIndexOperand();
+          Builder.SetInsertPoint(Tr);
 
-        Builder.SetInsertPoint(Tr);
+          Value *HalfExtract = Builder.CreateExtractElement(&II, Idx);
+          HalfExtract->takeName(Tr);
 
-        Value *HalfExtract = Builder.CreateExtractElement(&II, Idx);
-        HalfExtract->takeName(Tr);
+          Tr->replaceAllUsesWith(HalfExtract);
+        }
 
-        Tr->replaceAllUsesWith(HalfExtract);
-      }
+        for (auto &[Ext, Tr] : ExtractTruncPairs) {
+          IC.eraseInstFromFunction(*Tr);
+          IC.eraseInstFromFunction(*Ext);
+        }
 
-      for (auto &[Ext, Tr] : ExtractTruncPairs) {
-        IC.eraseInstFromFunction(*Tr);
-        IC.eraseInstFromFunction(*Ext);
+        return &II;
       }
-
-      return &II;
     }
   }