-// $Id$ -*-c++-*-
-//***************************************************************************
-// File:
-// MachineFrameInfo.h
-//
-// Purpose:
-// Interface to layout of stack frame on target machine.
-//
-// History:
-// 11/6/01 - Vikram Adve - Created
-//**************************************************************************/
+//===-- llvm/Target/TargetFrameInfo.h ---------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Interface to describe the layout of a stack frame on the target machine.
+//
+//===----------------------------------------------------------------------===//
-#ifndef LLVM_CODEGEN_FRAMEINFO_H
-#define LLVM_CODEGEN_FRAMEINFO_H
+#ifndef LLVM_TARGET_TARGETFRAMEINFO_H
+#define LLVM_TARGET_TARGETFRAMEINFO_H
-#include "Support/NonCopyable.h"
-#include <vector>
+#include <utility>
+namespace llvm {
-//************************* Forward Declarations **************************/
+/// Information about stack frame layout on the target. It holds the direction
+/// of stack growth, the known stack alignment on entry to each function, and
+/// the offset to the locals area.
+///
+/// The offset to the local area is the offset from the stack pointer on
+/// function entry to the first location where function data (local variables,
+/// spill locations) can be stored.
+class TargetFrameInfo {
+public:
+ enum StackDirection {
+ StackGrowsUp, // Adding to the stack increases the stack address
+ StackGrowsDown // Adding to the stack decreases the stack address
+ };
+private:
+ StackDirection StackDir;
+ unsigned StackAlignment;
+ int LocalAreaOffset;
+public:
+ TargetFrameInfo(StackDirection D, unsigned StackAl, int LAO)
+ : StackDir(D), StackAlignment(StackAl), LocalAreaOffset(LAO) {}
-class MachineCodeForMethod;
-class TargetMachine;
+ virtual ~TargetFrameInfo();
+ // These methods return information that describes the abstract stack layout
+ // of the target machine.
-//*************************** External Classes ****************************/
+ /// getStackGrowthDirection - Return the direction the stack grows
+ ///
+ StackDirection getStackGrowthDirection() const { return StackDir; }
+ /// getStackAlignment - This method returns the number of bytes that the stack
+ /// pointer must be aligned to. Typically, this is the largest alignment for
+ /// any data object in the target.
+ ///
+ unsigned getStackAlignment() const { return StackAlignment; }
-class MachineFrameInfo : public NonCopyableV {
-public:
- const TargetMachine& target;
-
-public:
- /*ctor*/ MachineFrameInfo(const TargetMachine& tgt) : target(tgt) {}
-
- //
- // These methods provide constant parameters of the frame layout.
- //
- virtual int getStackFrameSizeAlignment () const = 0;
- virtual int getMinStackFrameSize () const = 0;
- virtual int getNumFixedOutgoingArgs () const = 0;
- virtual int getSizeOfEachArgOnStack () const = 0;
- virtual bool argsOnStackHaveFixedSize () const = 0;
-
- //
- // These methods compute offsets using the frame contents for a
- // particular method. The frame contents are obtained from the
- // MachineCodeInfoForMethod object for the given method.
- // The first few methods have default machine-independent implementations.
- // The rest must be implemented by the machine-specific subclass.
- //
- virtual int getIncomingArgOffset (MachineCodeForMethod& mcInfo,
- unsigned argNum) const;
- virtual int getOutgoingArgOffset (MachineCodeForMethod& mcInfo,
- unsigned argNum) const;
-
- virtual int getFirstIncomingArgOffset (MachineCodeForMethod& mcInfo,
- bool& growUp) const=0;
- virtual int getFirstOutgoingArgOffset (MachineCodeForMethod& mcInfo,
- bool& growUp) const=0;
- virtual int getFirstOptionalOutgoingArgOffset (MachineCodeForMethod&,
- bool& growUp) const=0;
- virtual int getFirstAutomaticVarOffset (MachineCodeForMethod& mcInfo,
- bool& growUp) const=0;
- virtual int getRegSpillAreaOffset (MachineCodeForMethod& mcInfo,
- bool& growUp) const=0;
- virtual int getTmpAreaOffset (MachineCodeForMethod& mcInfo,
- bool& growUp) const=0;
- virtual int getDynamicAreaOffset (MachineCodeForMethod& mcInfo,
- bool& growUp) const=0;
+ /// getOffsetOfLocalArea - This method returns the offset of the local area
+ /// from the stack pointer on entrance to a function.
+ ///
+ int getOffsetOfLocalArea() const { return LocalAreaOffset; }
- //
- // These methods specify the base register used for each stack area
- // (generally FP or SP)
- //
- virtual int getIncomingArgBaseRegNum() const=0;
- virtual int getOutgoingArgBaseRegNum() const=0;
- virtual int getOptionalOutgoingArgBaseRegNum() const=0;
- virtual int getAutomaticVarBaseRegNum() const=0;
- virtual int getRegSpillAreaBaseRegNum() const=0;
- virtual int getDynamicAreaBaseRegNum() const=0;
+ /// getCalleeSavedSpillSlots - This method returns a pointer to an array of
+ /// pairs, that contains an entry for each callee saved register that must be
+ /// spilled to a particular stack location if it is spilled.
+ ///
+ /// Each entry in this array contains a <register,offset> pair, indicating the
+ /// fixed offset from the incoming stack pointer that each register should be
+ /// spilled at. If a register is not listed here, the code generator is
+ /// allowed to spill it anywhere it chooses.
+ ///
+ virtual const std::pair<unsigned, int> *
+ getCalleeSavedSpillSlots(unsigned &NumEntries) const {
+ NumEntries = 0;
+ return 0;
+ }
};
+} // End llvm namespace
+
#endif
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