[llvm] [SandboxIR] Implement PHINodes (PR #101111)

[via llvm-commits]

================
@@ -1290,6 +1292,97 @@ class GetElementPtrInst final : public Instruction {
 #endif
 };
 
+class PHINode final : public Instruction {
+  /// Use Context::createPHINode(). Don't call the
+  /// constructor directly.
+  PHINode(llvm::PHINode *PHI, Context &Ctx)
+      : Instruction(ClassID::PHI, Opcode::PHI, PHI, Ctx) {}
+  friend Context; // for SBPHINode()
+  Use getOperandUseInternal(unsigned OpIdx, bool Verify) const final {
+    return getOperandUseDefault(OpIdx, Verify);
+  }
+  SmallVector<llvm::Instruction *, 1> getLLVMInstrs() const final {
+    return {cast<llvm::Instruction>(Val)};
+  }
+  /// Helper for mapped_iterator.
+  struct LLVMBBToBB {
+    Context &Ctx;
+    LLVMBBToBB(Context &Ctx) : Ctx(Ctx) {}
+    BasicBlock *operator()(llvm::BasicBlock *LLVMBB) const;
+  };
+
+public:
+  unsigned getUseOperandNo(const Use &Use) const final {
+    return getUseOperandNoDefault(Use);
+  }
+  unsigned getNumOfIRInstrs() const final { return 1u; }
+  static PHINode *create(Type *Ty, unsigned NumReservedValues,
+                         Instruction *InsertBefore, Context &Ctx,
+                         const Twine &Name = "");
+  /// For isa/dyn_cast.
+  static bool classof(const Value *From);
+
+  using const_block_iterator =
+      mapped_iterator<llvm::PHINode::const_block_iterator, LLVMBBToBB>;
+
+  const_block_iterator block_begin() const {
+    LLVMBBToBB BBGetter(Ctx);
+    return const_block_iterator(cast<llvm::PHINode>(Val)->block_begin(),
+                                BBGetter);
+  }
+  const_block_iterator block_end() const {
+    LLVMBBToBB BBGetter(Ctx);
+    return const_block_iterator(cast<llvm::PHINode>(Val)->block_end(),
+                                BBGetter);
+  }
+  iterator_range<const_block_iterator> blocks() const {
+    return make_range(block_begin(), block_end());
+  }
+
+  op_range incoming_values() { return operands(); }
+
+  const_op_range incoming_values() const { return operands(); }
+
+  unsigned getNumIncomingValues() const {
+    return cast<llvm::PHINode>(Val)->getNumIncomingValues();
+  }
+  Value *getIncomingValue(unsigned Idx) const;
+  void setIncomingValue(unsigned Idx, Value *V);
+  static unsigned getOperandNumForIncomingValue(unsigned Idx) {
+    return llvm::PHINode::getOperandNumForIncomingValue(Idx);
+  }
+  static unsigned getIncomingValueNumForOperand(unsigned Idx) {
+    return llvm::PHINode::getIncomingValueNumForOperand(Idx);
+  }
+  BasicBlock *getIncomingBlock(unsigned Idx) const;
+  BasicBlock *getIncomingBlock(const Use &U) const;
+
+  void setIncomingBlock(unsigned Idx, BasicBlock *BB);
+
+  void addIncoming(Value *V, BasicBlock *BB);
+
+  Value *removeIncomingValue(unsigned Idx);
+  Value *removeIncomingValue(BasicBlock *BB);
+
+  int getBasicBlockIndex(const BasicBlock *BB) const;
+  Value *getIncomingValueForBlock(const BasicBlock *BB) const;
+
+  Value *hasConstantValue() const;
+
+  bool hasConstantOrUndefValue() const {
+    return cast<llvm::PHINode>(Val)->hasConstantOrUndefValue();
+  }
+  bool isComplete() const { return cast<llvm::PHINode>(Val)->isComplete(); }
+
----------------
vporpo wrote:

Some member functions have not been implemented yet, like `replaceIncomingBlockWith()`, `copyIncomingBlocks()`, `removeIncomingValueIf()`. Could you add a TODO in the code ?

https://github.com/llvm/llvm-project/pull/101111