clang/lib/CodeGen/CGBuilder.h

   1 //===-- CGBuilder.h - Choose IRBuilder implementation  ----------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_CLANG_LIB_CODEGEN_CGBUILDER_H
  10 #define LLVM_CLANG_LIB_CODEGEN_CGBUILDER_H
  11
  12 #include "Address.h"
  13 #include "CodeGenTypeCache.h"
  14 #include "llvm/IR/DataLayout.h"
  15 #include "llvm/IR/IRBuilder.h"
  16 #include "llvm/IR/Type.h"
  17
  18 namespace clang {
  19 namespace CodeGen {
  20
  21 class CodeGenFunction;
  22
  23 /// This is an IRBuilder insertion helper that forwards to
  24 /// CodeGenFunction::InsertHelper, which adds necessary metadata to
  25 /// instructions.
  26 class CGBuilderInserter final : public llvm::IRBuilderDefaultInserter {
  27 public:
  28   CGBuilderInserter() = default;
  29   explicit CGBuilderInserter(CodeGenFunction *CGF) : CGF(CGF) {}
  30
  31   /// This forwards to CodeGenFunction::InsertHelper.
  32   void InsertHelper(llvm::Instruction *I, const llvm::Twine &Name,
  33                     llvm::BasicBlock *BB,
  34                     llvm::BasicBlock::iterator InsertPt) const override;
  35
  36 private:
  37   CodeGenFunction *CGF = nullptr;
  38 };
  39
  40 typedef CGBuilderInserter CGBuilderInserterTy;
  41
  42 typedef llvm::IRBuilder<llvm::ConstantFolder, CGBuilderInserterTy>
  43     CGBuilderBaseTy;
  44
  45 class CGBuilderTy : public CGBuilderBaseTy {
  46   /// Storing a reference to the type cache here makes it a lot easier
  47   /// to build natural-feeling, target-specific IR.
  48   const CodeGenTypeCache &TypeCache;
  49
  50 public:
  51   CGBuilderTy(const CodeGenTypeCache &TypeCache, llvm::LLVMContext &C)
  52       : CGBuilderBaseTy(C), TypeCache(TypeCache) {}
  53   CGBuilderTy(const CodeGenTypeCache &TypeCache, llvm::LLVMContext &C,
  54               const llvm::ConstantFolder &F,
  55               const CGBuilderInserterTy &Inserter)
  56       : CGBuilderBaseTy(C, F, Inserter), TypeCache(TypeCache) {}
  57   CGBuilderTy(const CodeGenTypeCache &TypeCache, llvm::Instruction *I)
  58       : CGBuilderBaseTy(I), TypeCache(TypeCache) {}
  59   CGBuilderTy(const CodeGenTypeCache &TypeCache, llvm::BasicBlock *BB)
  60       : CGBuilderBaseTy(BB), TypeCache(TypeCache) {}
  61
  62   llvm::ConstantInt *getSize(CharUnits N) {
  63     return llvm::ConstantInt::get(TypeCache.SizeTy, N.getQuantity());
  64   }
  65   llvm::ConstantInt *getSize(uint64_t N) {
  66     return llvm::ConstantInt::get(TypeCache.SizeTy, N);
  67   }
  68
  69   // Note that we intentionally hide the CreateLoad APIs that don't
  70   // take an alignment.
  71   llvm::LoadInst *CreateLoad(Address Addr, const llvm::Twine &Name = "") {
  72     return CreateAlignedLoad(Addr.getElementType(), Addr.getPointer(),
  73                              Addr.getAlignment().getAsAlign(), Name);
  74   }
  75   llvm::LoadInst *CreateLoad(Address Addr, const char *Name) {
  76     // This overload is required to prevent string literals from
  77     // ending up in the IsVolatile overload.
  78     return CreateAlignedLoad(Addr.getElementType(), Addr.getPointer(),
  79                              Addr.getAlignment().getAsAlign(), Name);
  80   }
  81   llvm::LoadInst *CreateLoad(Address Addr, bool IsVolatile,
  82                              const llvm::Twine &Name = "") {
  83     return CreateAlignedLoad(Addr.getElementType(), Addr.getPointer(),
  84                              Addr.getAlignment().getAsAlign(), IsVolatile,
  85                              Name);
  86   }
  87
  88   using CGBuilderBaseTy::CreateAlignedLoad;
  89   llvm::LoadInst *CreateAlignedLoad(llvm::Type *Ty, llvm::Value *Addr,
  90                                     CharUnits Align,
  91                                     const llvm::Twine &Name = "") {
  92     return CreateAlignedLoad(Ty, Addr, Align.getAsAlign(), Name);
  93   }
  94
  95   // Note that we intentionally hide the CreateStore APIs that don't
  96   // take an alignment.
  97   llvm::StoreInst *CreateStore(llvm::Value *Val, Address Addr,
  98                                bool IsVolatile = false) {
  99     return CreateAlignedStore(Val, Addr.getPointer(),
 100                               Addr.getAlignment().getAsAlign(), IsVolatile);
 101   }
 102
 103   using CGBuilderBaseTy::CreateAlignedStore;
 104   llvm::StoreInst *CreateAlignedStore(llvm::Value *Val, llvm::Value *Addr,
 105                                       CharUnits Align,
 106                                       bool IsVolatile = false) {
 107     return CreateAlignedStore(Val, Addr, Align.getAsAlign(), IsVolatile);
 108   }
 109
 110   // FIXME: these "default-aligned" APIs should be removed,
 111   // but I don't feel like fixing all the builtin code right now.
 112   llvm::StoreInst *CreateDefaultAlignedStore(llvm::Value *Val,
 113                                              llvm::Value *Addr,
 114                                              bool IsVolatile = false) {
 115     return CGBuilderBaseTy::CreateStore(Val, Addr, IsVolatile);
 116   }
 117
 118   /// Emit a load from an i1 flag variable.
 119   llvm::LoadInst *CreateFlagLoad(llvm::Value *Addr,
 120                                  const llvm::Twine &Name = "") {
 121     return CreateAlignedLoad(getInt1Ty(), Addr, CharUnits::One(), Name);
 122   }
 123
 124   /// Emit a store to an i1 flag variable.
 125   llvm::StoreInst *CreateFlagStore(bool Value, llvm::Value *Addr) {
 126     return CreateAlignedStore(getInt1(Value), Addr, CharUnits::One());
 127   }
 128
 129   // Temporarily use old signature; clang will be updated to an Address overload
 130   // in a subsequent patch.
 131   llvm::AtomicCmpXchgInst *
 132   CreateAtomicCmpXchg(llvm::Value *Ptr, llvm::Value *Cmp, llvm::Value *New,
 133                       llvm::AtomicOrdering SuccessOrdering,
 134                       llvm::AtomicOrdering FailureOrdering,
 135                       llvm::SyncScope::ID SSID = llvm::SyncScope::System) {
 136     return CGBuilderBaseTy::CreateAtomicCmpXchg(
 137         Ptr, Cmp, New, llvm::MaybeAlign(), SuccessOrdering, FailureOrdering,
 138         SSID);
 139   }
 140
 141   // Temporarily use old signature; clang will be updated to an Address overload
 142   // in a subsequent patch.
 143   llvm::AtomicRMWInst *
 144   CreateAtomicRMW(llvm::AtomicRMWInst::BinOp Op, llvm::Value *Ptr,
 145                   llvm::Value *Val, llvm::AtomicOrdering Ordering,
 146                   llvm::SyncScope::ID SSID = llvm::SyncScope::System) {
 147     return CGBuilderBaseTy::CreateAtomicRMW(Op, Ptr, Val, llvm::MaybeAlign(),
 148                                             Ordering, SSID);
 149   }
 150
 151   using CGBuilderBaseTy::CreateAddrSpaceCast;
 152   Address CreateAddrSpaceCast(Address Addr, llvm::Type *Ty,
 153                               const llvm::Twine &Name = "") {
 154     return Addr.withPointer(CreateAddrSpaceCast(Addr.getPointer(), Ty, Name),
 155                             Addr.isKnownNonNull());
 156   }
 157
 158   /// Cast the element type of the given address to a different type,
 159   /// preserving information like the alignment and address space.
 160   Address CreateElementBitCast(Address Addr, llvm::Type *Ty,
 161                                const llvm::Twine &Name = "") {
 162     auto *PtrTy = Ty->getPointerTo(Addr.getAddressSpace());
 163     return Address(CreateBitCast(Addr.getPointer(), PtrTy, Name), Ty,
 164                    Addr.getAlignment(), Addr.isKnownNonNull());
 165   }
 166
 167   using CGBuilderBaseTy::CreatePointerBitCastOrAddrSpaceCast;
 168   Address CreatePointerBitCastOrAddrSpaceCast(Address Addr, llvm::Type *Ty,
 169                                               llvm::Type *ElementTy,
 170                                               const llvm::Twine &Name = "") {
 171     llvm::Value *Ptr =
 172         CreatePointerBitCastOrAddrSpaceCast(Addr.getPointer(), Ty, Name);
 173     return Address(Ptr, ElementTy, Addr.getAlignment(), Addr.isKnownNonNull());
 174   }
 175
 176   /// Given
 177   ///   %addr = {T1, T2...}* ...
 178   /// produce
 179   ///   %name = getelementptr inbounds %addr, i32 0, i32 index
 180   ///
 181   /// This API assumes that drilling into a struct like this is always an
 182   /// inbounds operation.
 183   using CGBuilderBaseTy::CreateStructGEP;
 184   Address CreateStructGEP(Address Addr, unsigned Index,
 185                           const llvm::Twine &Name = "") {
 186     llvm::StructType *ElTy = cast<llvm::StructType>(Addr.getElementType());
 187     const llvm::DataLayout &DL = BB->getParent()->getParent()->getDataLayout();
 188     const llvm::StructLayout *Layout = DL.getStructLayout(ElTy);
 189     auto Offset = CharUnits::fromQuantity(Layout->getElementOffset(Index));
 190
 191     return Address(
 192         CreateStructGEP(Addr.getElementType(), Addr.getPointer(), Index, Name),
 193         ElTy->getElementType(Index),
 194         Addr.getAlignment().alignmentAtOffset(Offset), Addr.isKnownNonNull());
 195   }
 196
 197   /// Given
 198   ///   %addr = [n x T]* ...
 199   /// produce
 200   ///   %name = getelementptr inbounds %addr, i64 0, i64 index
 201   /// where i64 is actually the target word size.
 202   ///
 203   /// This API assumes that drilling into an array like this is always
 204   /// an inbounds operation.
 205   Address CreateConstArrayGEP(Address Addr, uint64_t Index,
 206                               const llvm::Twine &Name = "") {
 207     llvm::ArrayType *ElTy = cast<llvm::ArrayType>(Addr.getElementType());
 208     const llvm::DataLayout &DL = BB->getParent()->getParent()->getDataLayout();
 209     CharUnits EltSize =
 210         CharUnits::fromQuantity(DL.getTypeAllocSize(ElTy->getElementType()));
 211
 212     return Address(
 213         CreateInBoundsGEP(Addr.getElementType(), Addr.getPointer(),
 214                           {getSize(CharUnits::Zero()), getSize(Index)}, Name),
 215         ElTy->getElementType(),
 216         Addr.getAlignment().alignmentAtOffset(Index * EltSize),
 217         Addr.isKnownNonNull());
 218   }
 219
 220   /// Given
 221   ///   %addr = T* ...
 222   /// produce
 223   ///   %name = getelementptr inbounds %addr, i64 index
 224   /// where i64 is actually the target word size.
 225   Address CreateConstInBoundsGEP(Address Addr, uint64_t Index,
 226                                  const llvm::Twine &Name = "") {
 227     llvm::Type *ElTy = Addr.getElementType();
 228     const llvm::DataLayout &DL = BB->getParent()->getParent()->getDataLayout();
 229     CharUnits EltSize = CharUnits::fromQuantity(DL.getTypeAllocSize(ElTy));
 230
 231     return Address(CreateInBoundsGEP(Addr.getElementType(), Addr.getPointer(),
 232                                      getSize(Index), Name),
 233                    ElTy, Addr.getAlignment().alignmentAtOffset(Index * EltSize),
 234                    Addr.isKnownNonNull());
 235   }
 236
 237   /// Given
 238   ///   %addr = T* ...
 239   /// produce
 240   ///   %name = getelementptr inbounds %addr, i64 index
 241   /// where i64 is actually the target word size.
 242   Address CreateConstGEP(Address Addr, uint64_t Index,
 243                          const llvm::Twine &Name = "") {
 244     const llvm::DataLayout &DL = BB->getParent()->getParent()->getDataLayout();
 245     CharUnits EltSize =
 246         CharUnits::fromQuantity(DL.getTypeAllocSize(Addr.getElementType()));
 247
 248     return Address(CreateGEP(Addr.getElementType(), Addr.getPointer(),
 249                              getSize(Index), Name),
 250                    Addr.getElementType(),
 251                    Addr.getAlignment().alignmentAtOffset(Index * EltSize),
 252                    NotKnownNonNull);
 253   }
 254
 255   /// Create GEP with single dynamic index. The address alignment is reduced
 256   /// according to the element size.
 257   using CGBuilderBaseTy::CreateGEP;
 258   Address CreateGEP(Address Addr, llvm::Value *Index,
 259                     const llvm::Twine &Name = "") {
 260     const llvm::DataLayout &DL = BB->getParent()->getParent()->getDataLayout();
 261     CharUnits EltSize =
 262         CharUnits::fromQuantity(DL.getTypeAllocSize(Addr.getElementType()));
 263
 264     return Address(
 265         CreateGEP(Addr.getElementType(), Addr.getPointer(), Index, Name),
 266         Addr.getElementType(),
 267         Addr.getAlignment().alignmentOfArrayElement(EltSize), NotKnownNonNull);
 268   }
 269
 270   /// Given a pointer to i8, adjust it by a given constant offset.
 271   Address CreateConstInBoundsByteGEP(Address Addr, CharUnits Offset,
 272                                      const llvm::Twine &Name = "") {
 273     assert(Addr.getElementType() == TypeCache.Int8Ty);
 274     return Address(CreateInBoundsGEP(Addr.getElementType(), Addr.getPointer(),
 275                                      getSize(Offset), Name),
 276                    Addr.getElementType(),
 277                    Addr.getAlignment().alignmentAtOffset(Offset),
 278                    Addr.isKnownNonNull());
 279   }
 280   Address CreateConstByteGEP(Address Addr, CharUnits Offset,
 281                              const llvm::Twine &Name = "") {
 282     assert(Addr.getElementType() == TypeCache.Int8Ty);
 283     return Address(CreateGEP(Addr.getElementType(), Addr.getPointer(),
 284                              getSize(Offset), Name),
 285                    Addr.getElementType(),
 286                    Addr.getAlignment().alignmentAtOffset(Offset),
 287                    NotKnownNonNull);
 288   }
 289
 290   using CGBuilderBaseTy::CreateConstInBoundsGEP2_32;
 291   Address CreateConstInBoundsGEP2_32(Address Addr, unsigned Idx0, unsigned Idx1,
 292                                      const llvm::Twine &Name = "") {
 293     const llvm::DataLayout &DL = BB->getParent()->getParent()->getDataLayout();
 294
 295     auto *GEP = cast<llvm::GetElementPtrInst>(CreateConstInBoundsGEP2_32(
 296         Addr.getElementType(), Addr.getPointer(), Idx0, Idx1, Name));
 297     llvm::APInt Offset(
 298         DL.getIndexSizeInBits(Addr.getType()->getPointerAddressSpace()), 0,
 299         /*isSigned=*/true);
 300     if (!GEP->accumulateConstantOffset(DL, Offset))
 301       llvm_unreachable("offset of GEP with constants is always computable");
 302     return Address(GEP, GEP->getResultElementType(),
 303                    Addr.getAlignment().alignmentAtOffset(
 304                        CharUnits::fromQuantity(Offset.getSExtValue())),
 305                    Addr.isKnownNonNull());
 306   }
 307
 308   using CGBuilderBaseTy::CreateMemCpy;
 309   llvm::CallInst *CreateMemCpy(Address Dest, Address Src, llvm::Value *Size,
 310                                bool IsVolatile = false) {
 311     return CreateMemCpy(Dest.getPointer(), Dest.getAlignment().getAsAlign(),
 312                         Src.getPointer(), Src.getAlignment().getAsAlign(), Size,
 313                         IsVolatile);
 314   }
 315   llvm::CallInst *CreateMemCpy(Address Dest, Address Src, uint64_t Size,
 316                                bool IsVolatile = false) {
 317     return CreateMemCpy(Dest.getPointer(), Dest.getAlignment().getAsAlign(),
 318                         Src.getPointer(), Src.getAlignment().getAsAlign(), Size,
 319                         IsVolatile);
 320   }
 321
 322   using CGBuilderBaseTy::CreateMemCpyInline;
 323   llvm::CallInst *CreateMemCpyInline(Address Dest, Address Src, uint64_t Size) {
 324     return CreateMemCpyInline(
 325         Dest.getPointer(), Dest.getAlignment().getAsAlign(), Src.getPointer(),
 326         Src.getAlignment().getAsAlign(), getInt64(Size));
 327   }
 328
 329   using CGBuilderBaseTy::CreateMemMove;
 330   llvm::CallInst *CreateMemMove(Address Dest, Address Src, llvm::Value *Size,
 331                                 bool IsVolatile = false) {
 332     return CreateMemMove(Dest.getPointer(), Dest.getAlignment().getAsAlign(),
 333                          Src.getPointer(), Src.getAlignment().getAsAlign(),
 334                          Size, IsVolatile);
 335   }
 336
 337   using CGBuilderBaseTy::CreateMemSet;
 338   llvm::CallInst *CreateMemSet(Address Dest, llvm::Value *Value,
 339                                llvm::Value *Size, bool IsVolatile = false) {
 340     return CreateMemSet(Dest.getPointer(), Value, Size,
 341                         Dest.getAlignment().getAsAlign(), IsVolatile);
 342   }
 343
 344   using CGBuilderBaseTy::CreateMemSetInline;
 345   llvm::CallInst *CreateMemSetInline(Address Dest, llvm::Value *Value,
 346                                      uint64_t Size) {
 347     return CreateMemSetInline(Dest.getPointer(),
 348                               Dest.getAlignment().getAsAlign(), Value,
 349                               getInt64(Size));
 350   }
 351
 352   using CGBuilderBaseTy::CreatePreserveStructAccessIndex;
 353   Address CreatePreserveStructAccessIndex(Address Addr, unsigned Index,
 354                                           unsigned FieldIndex,
 355                                           llvm::MDNode *DbgInfo) {
 356     llvm::StructType *ElTy = cast<llvm::StructType>(Addr.getElementType());
 357     const llvm::DataLayout &DL = BB->getParent()->getParent()->getDataLayout();
 358     const llvm::StructLayout *Layout = DL.getStructLayout(ElTy);
 359     auto Offset = CharUnits::fromQuantity(Layout->getElementOffset(Index));
 360
 361     return Address(CreatePreserveStructAccessIndex(ElTy, Addr.getPointer(),
 362                                                    Index, FieldIndex, DbgInfo),
 363                    ElTy->getElementType(Index),
 364                    Addr.getAlignment().alignmentAtOffset(Offset));
 365   }
 366
 367   using CGBuilderBaseTy::CreateLaunderInvariantGroup;
 368   Address CreateLaunderInvariantGroup(Address Addr) {
 369     return Addr.withPointer(CreateLaunderInvariantGroup(Addr.getPointer()),
 370                             Addr.isKnownNonNull());
 371   }
 372 };
 373
 374 } // end namespace CodeGen
 375 } // end namespace clang
 376
 377 #endif