//===-- CGBuilder.h - Choose IRBuilder implementation  ----------*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_LIB_CODEGEN_CGBUILDER_H

#define LLVM_CLANG_LIB_CODEGEN_CGBUILDER_H

#include "Address.h"

#include "CodeGenTypeCache.h"

#include "llvm/IR/DataLayout.h"

#include "llvm/IR/IRBuilder.h"

#include "llvm/IR/Type.h"

namespace clang {

namespace CodeGen {

class CodeGenFunction;

/// This is an IRBuilder insertion helper that forwards to

/// CodeGenFunction::InsertHelper, which adds necessary metadata to

/// instructions.

class CGBuilderInserter final : public llvm::IRBuilderDefaultInserter {

public:

  CGBuilderInserter() = default;

  explicit CGBuilderInserter(CodeGenFunction *CGF) : CGF(CGF) {}

  /// This forwards to CodeGenFunction::InsertHelper.

  void InsertHelper(llvm::Instruction *I, const llvm::Twine &Name,

                    llvm::BasicBlock *BB,

                    llvm::BasicBlock::iterator InsertPt) const override;

private:

  CodeGenFunction *CGF = nullptr;

};

typedef CGBuilderInserter CGBuilderInserterTy;

typedef llvm::IRBuilder<llvm::ConstantFolder, CGBuilderInserterTy>

    CGBuilderBaseTy;

class CGBuilderTy : public CGBuilderBaseTy {

  /// Storing a reference to the type cache here makes it a lot easier

  /// to build natural-feeling, target-specific IR.

  const CodeGenTypeCache &TypeCache;

public:

  CGBuilderTy(const CodeGenTypeCache &TypeCache, llvm::LLVMContext &C)

      : CGBuilderBaseTy(C), TypeCache(TypeCache) {}

  CGBuilderTy(const CodeGenTypeCache &TypeCache, llvm::LLVMContext &C,

              const llvm::ConstantFolder &F,

              const CGBuilderInserterTy &Inserter)

      : CGBuilderBaseTy(C, F, Inserter), TypeCache(TypeCache) {}

  CGBuilderTy(const CodeGenTypeCache &TypeCache, llvm::Instruction *I)

      : CGBuilderBaseTy(I), TypeCache(TypeCache) {}

  CGBuilderTy(const CodeGenTypeCache &TypeCache, llvm::BasicBlock *BB)

      : CGBuilderBaseTy(BB), TypeCache(TypeCache) {}

  llvm::ConstantInt *getSize(CharUnits N) {

    return llvm::ConstantInt::get(TypeCache.SizeTy, N.getQuantity());

  }

  llvm::ConstantInt *getSize(uint64_t N) {

    return llvm::ConstantInt::get(TypeCache.SizeTy, N);

  }

  // Note that we intentionally hide the CreateLoad APIs that don't

  // take an alignment.

  llvm::LoadInst *CreateLoad(Address Addr, const llvm::Twine &Name = "") {

    return CreateAlignedLoad(Addr.getElementType(), Addr.getPointer(),

                             Addr.getAlignment().getAsAlign(), Name);

  }

  llvm::LoadInst *CreateLoad(Address Addr, const char *Name) {

    // This overload is required to prevent string literals from

    // ending up in the IsVolatile overload.

    return CreateAlignedLoad(Addr.getElementType(), Addr.getPointer(),

                             Addr.getAlignment().getAsAlign(), Name);

  }

  llvm::LoadInst *CreateLoad(Address Addr, bool IsVolatile,

                             const llvm::Twine &Name = "") {

    return CreateAlignedLoad(Addr.getElementType(), Addr.getPointer(),

                             Addr.getAlignment().getAsAlign(), IsVolatile,

                             Name);

  }

  using CGBuilderBaseTy::CreateAlignedLoad;

  llvm::LoadInst *CreateAlignedLoad(llvm::Type *Ty, llvm::Value *Addr,

                                    CharUnits Align,

                                    const llvm::Twine &Name = "") {

    assert(llvm::cast<llvm::PointerType>(Addr->getType())

               ->isOpaqueOrPointeeTypeMatches(Ty));

    return CreateAlignedLoad(Ty, Addr, Align.getAsAlign(), Name);

  }

  // Note that we intentionally hide the CreateStore APIs that don't

  // take an alignment.

  llvm::StoreInst *CreateStore(llvm::Value *Val, Address Addr,

                               bool IsVolatile = false) {

    return CreateAlignedStore(Val, Addr.getPointer(),

                              Addr.getAlignment().getAsAlign(), IsVolatile);

  }

  using CGBuilderBaseTy::CreateAlignedStore;

  llvm::StoreInst *CreateAlignedStore(llvm::Value *Val, llvm::Value *Addr,

                                      CharUnits Align,

                                      bool IsVolatile = false) {

    return CreateAlignedStore(Val, Addr, Align.getAsAlign(), IsVolatile);

  }

  // FIXME: these "default-aligned" APIs should be removed,

  // but I don't feel like fixing all the builtin code right now.

  llvm::StoreInst *CreateDefaultAlignedStore(llvm::Value *Val,

                                             llvm::Value *Addr,

                                             bool IsVolatile = false) {

    return CGBuilderBaseTy::CreateStore(Val, Addr, IsVolatile);

  }

  /// Emit a load from an i1 flag variable.

  llvm::LoadInst *CreateFlagLoad(llvm::Value *Addr,

                                 const llvm::Twine &Name = "") {

    assert(llvm::cast<llvm::PointerType>(Addr->getType())

               ->isOpaqueOrPointeeTypeMatches(getInt1Ty()));

    return CreateAlignedLoad(getInt1Ty(), Addr, CharUnits::One(), Name);

  }

  /// Emit a store to an i1 flag variable.

  llvm::StoreInst *CreateFlagStore(bool Value, llvm::Value *Addr) {

    assert(llvm::cast<llvm::PointerType>(Addr->getType())

               ->isOpaqueOrPointeeTypeMatches(getInt1Ty()));

    return CreateAlignedStore(getInt1(Value), Addr, CharUnits::One());

  }

  // Temporarily use old signature; clang will be updated to an Address overload

  // in a subsequent patch.

  llvm::AtomicCmpXchgInst *

  CreateAtomicCmpXchg(llvm::Value *Ptr, llvm::Value *Cmp, llvm::Value *New,

                      llvm::AtomicOrdering SuccessOrdering,

                      llvm::AtomicOrdering FailureOrdering,

                      llvm::SyncScope::ID SSID = llvm::SyncScope::System) {

    return CGBuilderBaseTy::CreateAtomicCmpXchg(

        Ptr, Cmp, New, llvm::MaybeAlign(), SuccessOrdering, FailureOrdering,

        SSID);

  }

  // Temporarily use old signature; clang will be updated to an Address overload

  // in a subsequent patch.

  llvm::AtomicRMWInst *

  CreateAtomicRMW(llvm::AtomicRMWInst::BinOp Op, llvm::Value *Ptr,

                  llvm::Value *Val, llvm::AtomicOrdering Ordering,

                  llvm::SyncScope::ID SSID = llvm::SyncScope::System) {

    return CGBuilderBaseTy::CreateAtomicRMW(Op, Ptr, Val, llvm::MaybeAlign(),

                                            Ordering, SSID);

  }

  using CGBuilderBaseTy::CreateAddrSpaceCast;

  Address CreateAddrSpaceCast(Address Addr, llvm::Type *Ty,

                              const llvm::Twine &Name = "") {

    assert(cast<llvm::PointerType>(Ty)->isOpaqueOrPointeeTypeMatches(

               Addr.getElementType()) &&

           "Should not change the element type");

    return Addr.withPointer(CreateAddrSpaceCast(Addr.getPointer(), Ty, Name));

  }

  /// Cast the element type of the given address to a different type,

  /// preserving information like the alignment and address space.

  Address CreateElementBitCast(Address Addr, llvm::Type *Ty,

                               const llvm::Twine &Name = "") {

    auto *PtrTy = Ty->getPointerTo(Addr.getAddressSpace());

    return Address(CreateBitCast(Addr.getPointer(), PtrTy, Name), Ty,

                   Addr.getAlignment());

  }

  using CGBuilderBaseTy::CreatePointerBitCastOrAddrSpaceCast;

  Address CreatePointerBitCastOrAddrSpaceCast(Address Addr, llvm::Type *Ty,

                                              llvm::Type *ElementTy,

                                              const llvm::Twine &Name = "") {

    llvm::Value *Ptr =

        CreatePointerBitCastOrAddrSpaceCast(Addr.getPointer(), Ty, Name);

    return Address(Ptr, ElementTy, Addr.getAlignment());

  }

  /// Given

  ///   %addr = {T1, T2...}* ...

  /// produce

  ///   %name = getelementptr inbounds %addr, i32 0, i32 index

  ///

  /// This API assumes that drilling into a struct like this is always an

  /// inbounds operation.

  using CGBuilderBaseTy::CreateStructGEP;

  Address CreateStructGEP(Address Addr, unsigned Index,

                          const llvm::Twine &Name = "") {

    llvm::StructType *ElTy = cast<llvm::StructType>(Addr.getElementType());

    const llvm::DataLayout &DL = BB->getParent()->getParent()->getDataLayout();

    const llvm::StructLayout *Layout = DL.getStructLayout(ElTy);

    auto Offset = CharUnits::fromQuantity(Layout->getElementOffset(Index));

    return Address(

        CreateStructGEP(Addr.getElementType(), Addr.getPointer(), Index, Name),

        ElTy->getElementType(Index),

        Addr.getAlignment().alignmentAtOffset(Offset));

  }

  /// Given

  ///   %addr = [n x T]* ...

  /// produce

  ///   %name = getelementptr inbounds %addr, i64 0, i64 index

  /// where i64 is actually the target word size.

  ///

  /// This API assumes that drilling into an array like this is always

  /// an inbounds operation.

  Address CreateConstArrayGEP(Address Addr, uint64_t Index,

                              const llvm::Twine &Name = "") {

    llvm::ArrayType *ElTy = cast<llvm::ArrayType>(Addr.getElementType());

    const llvm::DataLayout &DL = BB->getParent()->getParent()->getDataLayout();

    CharUnits EltSize =

        CharUnits::fromQuantity(DL.getTypeAllocSize(ElTy->getElementType()));

    return Address(

        CreateInBoundsGEP(Addr.getElementType(), Addr.getPointer(),

                          {getSize(CharUnits::Zero()), getSize(Index)}, Name),

        ElTy->getElementType(),

        Addr.getAlignment().alignmentAtOffset(Index * EltSize));

  }

  /// Given

  ///   %addr = T* ...

  /// produce

  ///   %name = getelementptr inbounds %addr, i64 index

  /// where i64 is actually the target word size.

  Address CreateConstInBoundsGEP(Address Addr, uint64_t Index,

                                 const llvm::Twine &Name = "") {

    llvm::Type *ElTy = Addr.getElementType();

    const llvm::DataLayout &DL = BB->getParent()->getParent()->getDataLayout();

    CharUnits EltSize = CharUnits::fromQuantity(DL.getTypeAllocSize(ElTy));

    return Address(CreateInBoundsGEP(Addr.getElementType(), Addr.getPointer(),

                                     getSize(Index), Name),

                   ElTy,

                   Addr.getAlignment().alignmentAtOffset(Index * EltSize));

  }

  /// Given

  ///   %addr = T* ...

  /// produce

  ///   %name = getelementptr inbounds %addr, i64 index

  /// where i64 is actually the target word size.

  Address CreateConstGEP(Address Addr, uint64_t Index,

                         const llvm::Twine &Name = "") {

    const llvm::DataLayout &DL = BB->getParent()->getParent()->getDataLayout();

    CharUnits EltSize =

        CharUnits::fromQuantity(DL.getTypeAllocSize(Addr.getElementType()));

    return Address(CreateGEP(Addr.getElementType(), Addr.getPointer(),

                             getSize(Index), Name),

                   Addr.getElementType(),

                   Addr.getAlignment().alignmentAtOffset(Index * EltSize));

  }

  /// Create GEP with single dynamic index. The address alignment is reduced

  /// according to the element size.

  using CGBuilderBaseTy::CreateGEP;

  Address CreateGEP(Address Addr, llvm::Value *Index,

                    const llvm::Twine &Name = "") {

    const llvm::DataLayout &DL = BB->getParent()->getParent()->getDataLayout();

    CharUnits EltSize =

        CharUnits::fromQuantity(DL.getTypeAllocSize(Addr.getElementType()));

    return Address(

        CreateGEP(Addr.getElementType(), Addr.getPointer(), Index, Name),

        Addr.getElementType(),

        Addr.getAlignment().alignmentOfArrayElement(EltSize));

  }

  /// Given a pointer to i8, adjust it by a given constant offset.

  Address CreateConstInBoundsByteGEP(Address Addr, CharUnits Offset,

                                     const llvm::Twine &Name = "") {

    assert(Addr.getElementType() == TypeCache.Int8Ty);

    return Address(CreateInBoundsGEP(Addr.getElementType(), Addr.getPointer(),

                                     getSize(Offset), Name),

                   Addr.getElementType(),

                   Addr.getAlignment().alignmentAtOffset(Offset));

  }

  Address CreateConstByteGEP(Address Addr, CharUnits Offset,

                             const llvm::Twine &Name = "") {

    assert(Addr.getElementType() == TypeCache.Int8Ty);

    return Address(CreateGEP(Addr.getElementType(), Addr.getPointer(),

                             getSize(Offset), Name),

                   Addr.getElementType(),

                   Addr.getAlignment().alignmentAtOffset(Offset));

  }

  using CGBuilderBaseTy::CreateConstInBoundsGEP2_32;

  Address CreateConstInBoundsGEP2_32(Address Addr, unsigned Idx0, unsigned Idx1,

                                     const llvm::Twine &Name = "") {

    const llvm::DataLayout &DL = BB->getParent()->getParent()->getDataLayout();

    auto *GEP = cast<llvm::GetElementPtrInst>(CreateConstInBoundsGEP2_32(

        Addr.getElementType(), Addr.getPointer(), Idx0, Idx1, Name));

    llvm::APInt Offset(

        DL.getIndexSizeInBits(Addr.getType()->getPointerAddressSpace()), 0,

        /*isSigned=*/true);

    if (!GEP->accumulateConstantOffset(DL, Offset))

      llvm_unreachable("offset of GEP with constants is always computable");

    return Address(GEP, GEP->getResultElementType(),

                   Addr.getAlignment().alignmentAtOffset(

                       CharUnits::fromQuantity(Offset.getSExtValue())));

  }

  using CGBuilderBaseTy::CreateMemCpy;

  llvm::CallInst *CreateMemCpy(Address Dest, Address Src, llvm::Value *Size,

                               bool IsVolatile = false) {

    return CreateMemCpy(Dest.getPointer(), Dest.getAlignment().getAsAlign(),

                        Src.getPointer(), Src.getAlignment().getAsAlign(), Size,

                        IsVolatile);

  }

  llvm::CallInst *CreateMemCpy(Address Dest, Address Src, uint64_t Size,

                               bool IsVolatile = false) {

    return CreateMemCpy(Dest.getPointer(), Dest.getAlignment().getAsAlign(),

                        Src.getPointer(), Src.getAlignment().getAsAlign(), Size,

                        IsVolatile);

  }

  using CGBuilderBaseTy::CreateMemCpyInline;

  llvm::CallInst *CreateMemCpyInline(Address Dest, Address Src, uint64_t Size) {

    return CreateMemCpyInline(

        Dest.getPointer(), Dest.getAlignment().getAsAlign(), Src.getPointer(),

        Src.getAlignment().getAsAlign(), getInt64(Size));

  }

  using CGBuilderBaseTy::CreateMemMove;

  llvm::CallInst *CreateMemMove(Address Dest, Address Src, llvm::Value *Size,

                                bool IsVolatile = false) {

    return CreateMemMove(Dest.getPointer(), Dest.getAlignment().getAsAlign(),

                         Src.getPointer(), Src.getAlignment().getAsAlign(),

                         Size, IsVolatile);

  }

  using CGBuilderBaseTy::CreateMemSet;

  llvm::CallInst *CreateMemSet(Address Dest, llvm::Value *Value,

                               llvm::Value *Size, bool IsVolatile = false) {

    return CreateMemSet(Dest.getPointer(), Value, Size,

                        Dest.getAlignment().getAsAlign(), IsVolatile);

  }

  using CGBuilderBaseTy::CreateMemSetInline;

  llvm::CallInst *CreateMemSetInline(Address Dest, llvm::Value *Value,

                                     uint64_t Size) {

    return CreateMemSetInline(Dest.getPointer(),

                              Dest.getAlignment().getAsAlign(), Value,

                              getInt64(Size));

  }

  using CGBuilderBaseTy::CreatePreserveStructAccessIndex;

  Address CreatePreserveStructAccessIndex(Address Addr, unsigned Index,

                                          unsigned FieldIndex,

                                          llvm::MDNode *DbgInfo) {

    llvm::StructType *ElTy = cast<llvm::StructType>(Addr.getElementType());

    const llvm::DataLayout &DL = BB->getParent()->getParent()->getDataLayout();

    const llvm::StructLayout *Layout = DL.getStructLayout(ElTy);

    auto Offset = CharUnits::fromQuantity(Layout->getElementOffset(Index));

    return Address(CreatePreserveStructAccessIndex(ElTy, Addr.getPointer(),

                                                   Index, FieldIndex, DbgInfo),

                   ElTy->getElementType(Index),

                   Addr.getAlignment().alignmentAtOffset(Offset));

  }

  using CGBuilderBaseTy::CreateLaunderInvariantGroup;

  Address CreateLaunderInvariantGroup(Address Addr) {

    return Addr.withPointer(CreateLaunderInvariantGroup(Addr.getPointer()));

  }

};

} // end namespace CodeGen

} // end namespace clang

#endif