Import LLVM, at r72732.

1 files changed, 317 insertions, 0 deletions

diff --git a/include/llvm/Target/TargetData.h b/include/llvm/Target/TargetData.h
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+//===-- llvm/Target/TargetData.h - Data size & alignment info ---*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines target properties related to datatype size/offset/alignment
+// information.  It uses lazy annotations to cache information about how
+// structure types are laid out and used.
+//
+// This structure should be created once, filled in if the defaults are not
+// correct and then passed around by const&.  None of the members functions
+// require modification to the object.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TARGET_TARGETDATA_H
+#define LLVM_TARGET_TARGETDATA_H
+
+#include "llvm/Pass.h"
+#include "llvm/Support/DataTypes.h"
+#include "llvm/ADT/SmallVector.h"
+#include <string>
+
+namespace llvm {
+
+class Value;
+class Type;
+class IntegerType;
+class StructType;
+class StructLayout;
+class GlobalVariable;
+
+/// Enum used to categorize the alignment types stored by TargetAlignElem
+enum AlignTypeEnum {
+  INTEGER_ALIGN = 'i',               ///< Integer type alignment
+  VECTOR_ALIGN = 'v',                ///< Vector type alignment
+  FLOAT_ALIGN = 'f',                 ///< Floating point type alignment
+  AGGREGATE_ALIGN = 'a',             ///< Aggregate alignment
+  STACK_ALIGN = 's'                  ///< Stack objects alignment
+};
+/// Target alignment element.
+///
+/// Stores the alignment data associated with a given alignment type (pointer,
+/// integer, vector, float) and type bit width.
+///
+/// @note The unusual order of elements in the structure attempts to reduce
+/// padding and make the structure slightly more cache friendly.
+struct TargetAlignElem {
+  AlignTypeEnum       AlignType : 8;  //< Alignment type (AlignTypeEnum)
+  unsigned char       ABIAlign;       //< ABI alignment for this type/bitw
+  unsigned char       PrefAlign;      //< Pref. alignment for this type/bitw
+  uint32_t            TypeBitWidth;   //< Type bit width
+
+  /// Initializer
+  static TargetAlignElem get(AlignTypeEnum align_type, unsigned char abi_align,
+                             unsigned char pref_align, uint32_t bit_width);
+  /// Equality predicate
+  bool operator==(const TargetAlignElem &rhs) const;
+  /// output stream operator
+  std::ostream &dump(std::ostream &os) const;
+};
+
+class TargetData : public ImmutablePass {
+private:
+  bool          LittleEndian;          ///< Defaults to false
+  unsigned char PointerMemSize;        ///< Pointer size in bytes
+  unsigned char PointerABIAlign;       ///< Pointer ABI alignment
+  unsigned char PointerPrefAlign;      ///< Pointer preferred alignment
+
+  //! Where the primitive type alignment data is stored.
+  /*!
+   @sa init().
+   @note Could support multiple size pointer alignments, e.g., 32-bit pointers
+   vs. 64-bit pointers by extending TargetAlignment, but for now, we don't.
+   */
+  SmallVector<TargetAlignElem, 16> Alignments;
+  //! Alignment iterator shorthand
+  typedef SmallVector<TargetAlignElem, 16>::iterator align_iterator;
+  //! Constant alignment iterator shorthand
+  typedef SmallVector<TargetAlignElem, 16>::const_iterator align_const_iterator;
+  //! Invalid alignment.
+  /*!
+    This member is a signal that a requested alignment type and bit width were
+    not found in the SmallVector.
+   */
+  static const TargetAlignElem InvalidAlignmentElem;
+
+  //! Set/initialize target alignments
+  void setAlignment(AlignTypeEnum align_type, unsigned char abi_align,
+                    unsigned char pref_align, uint32_t bit_width);
+  unsigned getAlignmentInfo(AlignTypeEnum align_type, uint32_t bit_width,
+                            bool ABIAlign, const Type *Ty) const;
+  //! Internal helper method that returns requested alignment for type.
+  unsigned char getAlignment(const Type *Ty, bool abi_or_pref) const;
+
+  /// Valid alignment predicate.
+  ///
+  /// Predicate that tests a TargetAlignElem reference returned by get() against
+  /// InvalidAlignmentElem.
+  inline bool validAlignment(const TargetAlignElem &align) const {
+    return (&align != &InvalidAlignmentElem);
+  }
+
+public:
+  /// Default ctor.
+  ///
+  /// @note This has to exist, because this is a pass, but it should never be
+  /// used.
+  TargetData() : ImmutablePass(&ID) {
+    assert(0 && "ERROR: Bad TargetData ctor used.  "
+           "Tool did not specify a TargetData to use?");
+    abort();
+  }
+
+  /// Constructs a TargetData from a specification string. See init().
+  explicit TargetData(const std::string &TargetDescription)
+    : ImmutablePass(&ID) {
+    init(TargetDescription);
+  }
+
+  /// Initialize target data from properties stored in the module.
+  explicit TargetData(const Module *M);
+
+  TargetData(const TargetData &TD) :
+    ImmutablePass(&ID),
+    LittleEndian(TD.isLittleEndian()),
+    PointerMemSize(TD.PointerMemSize),
+    PointerABIAlign(TD.PointerABIAlign),
+    PointerPrefAlign(TD.PointerPrefAlign),
+    Alignments(TD.Alignments)
+  { }
+
+  ~TargetData();  // Not virtual, do not subclass this class
+
+  //! Parse a target data layout string and initialize TargetData alignments.
+  void init(const std::string &TargetDescription);
+
+  /// Target endianness...
+  bool          isLittleEndian()       const { return     LittleEndian; }
+  bool          isBigEndian()          const { return    !LittleEndian; }
+
+  /// getStringRepresentation - Return the string representation of the
+  /// TargetData.  This representation is in the same format accepted by the
+  /// string constructor above.
+  std::string getStringRepresentation() const;
+  /// Target pointer alignment
+  unsigned char getPointerABIAlignment() const { return PointerABIAlign; }
+  /// Return target's alignment for stack-based pointers
+  unsigned char getPointerPrefAlignment() const { return PointerPrefAlign; }
+  /// Target pointer size
+  unsigned char getPointerSize()         const { return PointerMemSize; }
+  /// Target pointer size, in bits
+  unsigned char getPointerSizeInBits()   const { return 8*PointerMemSize; }
+
+  /// Size examples:
+  ///
+  /// Type        SizeInBits  StoreSizeInBits  AllocSizeInBits[*]
+  /// ----        ----------  ---------------  ---------------
+  ///  i1            1           8                8
+  ///  i8            8           8                8
+  ///  i19          19          24               32
+  ///  i32          32          32               32
+  ///  i100        100         104              128
+  ///  i128        128         128              128
+  ///  Float        32          32               32
+  ///  Double       64          64               64
+  ///  X86_FP80     80          80               96
+  ///
+  /// [*] The alloc size depends on the alignment, and thus on the target.
+  ///     These values are for x86-32 linux.
+
+  /// getTypeSizeInBits - Return the number of bits necessary to hold the
+  /// specified type.  For example, returns 36 for i36 and 80 for x86_fp80.
+  uint64_t getTypeSizeInBits(const Type* Ty) const;
+
+  /// getTypeStoreSize - Return the maximum number of bytes that may be
+  /// overwritten by storing the specified type.  For example, returns 5
+  /// for i36 and 10 for x86_fp80.
+  uint64_t getTypeStoreSize(const Type *Ty) const {
+    return (getTypeSizeInBits(Ty)+7)/8;
+  }
+
+  /// getTypeStoreSizeInBits - Return the maximum number of bits that may be
+  /// overwritten by storing the specified type; always a multiple of 8.  For
+  /// example, returns 40 for i36 and 80 for x86_fp80.
+  uint64_t getTypeStoreSizeInBits(const Type *Ty) const {
+    return 8*getTypeStoreSize(Ty);
+  }
+
+  /// getTypeAllocSize - Return the offset in bytes between successive objects
+  /// of the specified type, including alignment padding.  This is the amount
+  /// that alloca reserves for this type.  For example, returns 12 or 16 for
+  /// x86_fp80, depending on alignment.
+  uint64_t getTypeAllocSize(const Type* Ty) const {
+    // Round up to the next alignment boundary.
+    return RoundUpAlignment(getTypeStoreSize(Ty), getABITypeAlignment(Ty));
+  }
+
+  /// getTypeAllocSizeInBits - Return the offset in bits between successive
+  /// objects of the specified type, including alignment padding; always a
+  /// multiple of 8.  This is the amount that alloca reserves for this type.
+  /// For example, returns 96 or 128 for x86_fp80, depending on alignment.
+  uint64_t getTypeAllocSizeInBits(const Type* Ty) const {
+    return 8*getTypeAllocSize(Ty);
+  }
+
+  /// getABITypeAlignment - Return the minimum ABI-required alignment for the
+  /// specified type.
+  unsigned char getABITypeAlignment(const Type *Ty) const;
+
+  /// getCallFrameTypeAlignment - Return the minimum ABI-required alignment
+  /// for the specified type when it is part of a call frame.
+  unsigned char getCallFrameTypeAlignment(const Type *Ty) const;
+
+
+  /// getPrefTypeAlignment - Return the preferred stack/global alignment for
+  /// the specified type.  This is always at least as good as the ABI alignment.
+  unsigned char getPrefTypeAlignment(const Type *Ty) const;
+
+  /// getPreferredTypeAlignmentShift - Return the preferred alignment for the
+  /// specified type, returned as log2 of the value (a shift amount).
+  ///
+  unsigned char getPreferredTypeAlignmentShift(const Type *Ty) const;
+
+  /// getIntPtrType - Return an unsigned integer type that is the same size or
+  /// greater to the host pointer size.
+  ///
+  const IntegerType *getIntPtrType() const;
+
+  /// getIndexedOffset - return the offset from the beginning of the type for
+  /// the specified indices.  This is used to implement getelementptr.
+  ///
+  uint64_t getIndexedOffset(const Type *Ty,
+                            Value* const* Indices, unsigned NumIndices) const;
+
+  /// getStructLayout - Return a StructLayout object, indicating the alignment
+  /// of the struct, its size, and the offsets of its fields.  Note that this
+  /// information is lazily cached.
+  const StructLayout *getStructLayout(const StructType *Ty) const;
+
+  /// InvalidateStructLayoutInfo - TargetData speculatively caches StructLayout
+  /// objects.  If a TargetData object is alive when types are being refined and
+  /// removed, this method must be called whenever a StructType is removed to
+  /// avoid a dangling pointer in this cache.
+  void InvalidateStructLayoutInfo(const StructType *Ty) const;
+
+  /// getPreferredAlignment - Return the preferred alignment of the specified
+  /// global.  This includes an explicitly requested alignment (if the global
+  /// has one).
+  unsigned getPreferredAlignment(const GlobalVariable *GV) const;
+
+  /// getPreferredAlignmentLog - Return the preferred alignment of the
+  /// specified global, returned in log form.  This includes an explicitly
+  /// requested alignment (if the global has one).
+  unsigned getPreferredAlignmentLog(const GlobalVariable *GV) const;
+
+  /// RoundUpAlignment - Round the specified value up to the next alignment
+  /// boundary specified by Alignment.  For example, 7 rounded up to an
+  /// alignment boundary of 4 is 8.  8 rounded up to the alignment boundary of 4
+  /// is 8 because it is already aligned.
+  template <typename UIntTy>
+  static UIntTy RoundUpAlignment(UIntTy Val, unsigned Alignment) {
+    assert((Alignment & (Alignment-1)) == 0 && "Alignment must be power of 2!");
+    return (Val + (Alignment-1)) & ~UIntTy(Alignment-1);
+  }
+  
+  static char ID; // Pass identification, replacement for typeid
+};
+
+/// StructLayout - used to lazily calculate structure layout information for a
+/// target machine, based on the TargetData structure.
+///
+class StructLayout {
+  uint64_t StructSize;
+  unsigned StructAlignment;
+  unsigned NumElements;
+  uint64_t MemberOffsets[1];  // variable sized array!
+public:
+
+  uint64_t getSizeInBytes() const {
+    return StructSize;
+  }
+
+  uint64_t getSizeInBits() const {
+    return 8*StructSize;
+  }
+
+  unsigned getAlignment() const {
+    return StructAlignment;
+  }
+
+  /// getElementContainingOffset - Given a valid byte offset into the structure,
+  /// return the structure index that contains it.
+  ///
+  unsigned getElementContainingOffset(uint64_t Offset) const;
+
+  uint64_t getElementOffset(unsigned Idx) const {
+    assert(Idx < NumElements && "Invalid element idx!");
+    return MemberOffsets[Idx];
+  }
+
+  uint64_t getElementOffsetInBits(unsigned Idx) const {
+    return getElementOffset(Idx)*8;
+  }
+
+private:
+  friend class TargetData;   // Only TargetData can create this class
+  StructLayout(const StructType *ST, const TargetData &TD);
+};
+
+} // End llvm namespace
+
+#endif