Provide support for detecting if the Win32 imaghlp and psapi libraries

[oota-llvm.git] / include / llvm / CodeGen / MachineConstantPool.h

diff --git a/include/llvm/CodeGen/MachineConstantPool.h b/include/llvm/CodeGen/MachineConstantPool.h
index edfd601faa1ec2b2d0523c6d79e87fd487e5cc9e..9c729b230a1ce3cbde7e8810baa1a7fb9a196f77 100644 (file)
--- a/include/llvm/CodeGen/MachineConstantPool.h
+++ b/include/llvm/CodeGen/MachineConstantPool.h
@@ -1,21 +1,14 @@
 //===-- CodeGen/MachineConstantPool.h - Abstract Constant Pool --*- C++ -*-===//
-// 
+//
 //                     The LLVM Compiler Infrastructure
 //
 // This file was developed by the LLVM research group and is distributed under
 // the University of Illinois Open Source License. See LICENSE.TXT for details.
-// 
+//
 //===----------------------------------------------------------------------===//
-// 
-// The MachineConstantPool class keeps track of constants referenced by a
-// function which must be spilled to memory.  This is used for constants which
-// are unable to be used directly as operands to instructions, which typically
-// include floating point and large integer constants.
 //
-// Instructions reference the address of these constant pool constants through
-// the use of MO_ConstantPoolIndex values.  When emitting assembly or machine
-// code, these virtual address references are converted to refer to the
-// address of the function constant pool values.
+/// @file This file declares the MachineConstantPool class which is an abstract
+/// constant pool to keep track of constants referenced by a function.
 //
 //===----------------------------------------------------------------------===//
 
@@ -23,37 +16,63 @@
 #define LLVM_CODEGEN_MACHINECONSTANTPOOL_H
 
 #include <vector>
+#include <iosfwd>
 
 namespace llvm {
 
 class Constant;
+class TargetData;
 
+/// This class is a data container for one entry in a MachineConstantPool.
+/// It contains a pointer to the value and an offset from the start of
+/// the constant pool.
+/// @brief An entry in a MachineConstantPool
+struct MachineConstantPoolEntry {
+  Constant *Val;   ///< The constant itself.
+  unsigned Offset; ///< The offset of the constant from the start of the pool.
+  MachineConstantPoolEntry(Constant *V, unsigned O) : Val(V), Offset(O) {}
+};
+  
+/// The MachineConstantPool class keeps track of constants referenced by a
+/// function which must be spilled to memory.  This is used for constants which
+/// are unable to be used directly as operands to instructions, which typically
+/// include floating point and large integer constants.
+///
+/// Instructions reference the address of these constant pool constants through
+/// the use of MO_ConstantPoolIndex values.  When emitting assembly or machine
+/// code, these virtual address references are converted to refer to the
+/// address of the function constant pool values.
+/// @brief The machine constant pool.
 class MachineConstantPool {
-  std::vector<Constant*> Constants;
+  const TargetData *TD;   ///< The machine's TargetData.
+  unsigned PoolAlignment; ///< The alignment for the pool.
+  std::vector<MachineConstantPoolEntry> Constants; ///< The pool of constants.
 public:
-
+  /// @brief The only constructor.
+  MachineConstantPool(const TargetData *td) : TD(td), PoolAlignment(1) {}
+    
+  /// getConstantPoolAlignment - Return the log2 of the alignment required by
+  /// the whole constant pool, of which the first element must be aligned.
+  unsigned getConstantPoolAlignment() const { return PoolAlignment; }
+  
   /// getConstantPoolIndex - Create a new entry in the constant pool or return
-  /// an existing one.
-  ///
-  unsigned getConstantPoolIndex(Constant *C) {
-    // Check to see if we already have this constant.
-    //
-    // FIXME, this could be made much more efficient for large constant pools.
-    for (unsigned i = 0, e = Constants.size(); i != e; ++i)
-      if (Constants[i] == C)
-        return i;
-    Constants.push_back(C);
-    return Constants.size()-1;
-  }
+  /// an existing one.  User must specify an alignment in bytes for the object.
+  unsigned getConstantPoolIndex(Constant *C, unsigned Alignment);
+  
+  /// isEmpty - Return true if this constant pool contains no constants.
+  bool isEmpty() const { return Constants.empty(); }
 
-  const std::vector<Constant*> &getConstants() const { return Constants; }
+  const std::vector<MachineConstantPoolEntry> &getConstants() const {
+    return Constants;
+  }
 
   /// print - Used by the MachineFunction printer to print information about
-  /// stack objects.  Implemented in MachineFunction.cpp
+  /// constant pool objects.  Implemented in MachineFunction.cpp
   ///
   void print(std::ostream &OS) const;
 
   /// dump - Call print(std::cerr) to be called from the debugger.
+  ///
   void dump() const;
 };