-//===-- CodeGen/FunctionFrameInfo.h - Abstract Stack Frame Rep --*- C++ -*-===//
-//
-// The FunctionFrameInfo class represents an abstract stack frame until
-// prolog/epilog code is inserted. This class is key to allowing stack frame
-// representation optimizations, such as frame pointer elimination. It also
-// allows more mundane (but still important) optimizations, such as reordering
-// of abstract objects on the stack frame.
+//===-- CodeGen/MachineFrameInfo.h - Abstract Stack Frame Rep. --*- C++ -*-===//
//
-// To support this, the class assigns unique integer identifiers to stack
-// objects requested clients. These identifiers are negative integers for fixed
-// stack objects (such as arguments passed on the stack) or positive for objects
-// that may be reordered. Instructions which refer to stack objects use a
-// special MO_FrameIndex operand to represent these frame indexes.
+// The LLVM Compiler Infrastructure
//
-// Because this class keeps track of all references to the stack frame, it knows
-// when a variable sized object is allocated on the stack. This is the sole
-// condition which prevents frame pointer elimination, which is an important
-// optimization on register-poor architectures. Because original variable sized
-// alloca's in the source program are the only source of variable sized stack
-// objects, it is safe to decide whether there will be any variable sized
-// objects before all stack objects are known (for example, register allocator
-// spill code never needs variable sized objects).
-//
-// When prolog/epilog code emission is performed, the final stack frame is built
-// and the machine instructions are modified to refer to the actual stack
-// offsets of the object, eliminating all MO_FrameIndex operands from the
-// program.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_CODEGEN_FUNCTIONFRAMEINFO_H
-#define LLVM_CODEGEN_FUNCTIONFRAMEINFO_H
-class FunctionFrameInfo {
+#ifndef LLVM_CODEGEN_MACHINEFRAMEINFO_H
+#define LLVM_CODEGEN_MACHINEFRAMEINFO_H
+
+#include <vector>
+
+namespace llvm {
+class TargetData;
+class TargetRegisterClass;
+class Type;
+class MachineModuleInfo;
+class MachineFunction;
+
+/// The CalleeSavedInfo class tracks the information need to locate where a
+/// callee saved register in the current frame.
+class CalleeSavedInfo {
+
+private:
+ unsigned Reg;
+ const TargetRegisterClass *RegClass;
+ int FrameIdx;
+
+public:
+ CalleeSavedInfo(unsigned R, const TargetRegisterClass *RC, int FI = 0)
+ : Reg(R)
+ , RegClass(RC)
+ , FrameIdx(FI)
+ {}
+
+ // Accessors.
+ unsigned getReg() const { return Reg; }
+ const TargetRegisterClass *getRegClass() const { return RegClass; }
+ int getFrameIdx() const { return FrameIdx; }
+ void setFrameIdx(int FI) { FrameIdx = FI; }
+};
+
+/// The MachineFrameInfo class represents an abstract stack frame until
+/// prolog/epilog code is inserted. This class is key to allowing stack frame
+/// representation optimizations, such as frame pointer elimination. It also
+/// allows more mundane (but still important) optimizations, such as reordering
+/// of abstract objects on the stack frame.
+///
+/// To support this, the class assigns unique integer identifiers to stack
+/// objects requested clients. These identifiers are negative integers for
+/// fixed stack objects (such as arguments passed on the stack) or positive
+/// for objects that may be reordered. Instructions which refer to stack
+/// objects use a special MO_FrameIndex operand to represent these frame
+/// indexes.
+///
+/// Because this class keeps track of all references to the stack frame, it
+/// knows when a variable sized object is allocated on the stack. This is the
+/// sole condition which prevents frame pointer elimination, which is an
+/// important optimization on register-poor architectures. Because original
+/// variable sized alloca's in the source program are the only source of
+/// variable sized stack objects, it is safe to decide whether there will be
+/// any variable sized objects before all stack objects are known (for
+/// example, register allocator spill code never needs variable sized
+/// objects).
+///
+/// When prolog/epilog code emission is performed, the final stack frame is
+/// built and the machine instructions are modified to refer to the actual
+/// stack offsets of the object, eliminating all MO_FrameIndex operands from
+/// the program.
+///
+/// @brief Abstract Stack Frame Information
+class MachineFrameInfo {
// StackObject - Represent a single object allocated on the stack.
struct StackObject {
// The size of this object on the stack. 0 means a variable sized object
- unsigned Size;
+ uint64_t Size;
// Alignment - The required alignment of this stack slot.
unsigned Alignment;
// SPOffset - The offset of this object from the stack pointer on entry to
// the function. This field has no meaning for a variable sized element.
- int SPOffset;
+ int64_t SPOffset;
- StackObject(unsigned Sz, unsigned Al, int SP)
+ StackObject(uint64_t Sz, unsigned Al, int64_t SP)
: Size(Sz), Alignment(Al), SPOffset(SP) {}
};
/// above. It then updates StackSize to contain the number of bytes that need
/// to be allocated on entry to the function.
///
- unsigned StackSize;
+ uint64_t StackSize;
+
+ /// OffsetAdjustment - The amount that a frame offset needs to be adjusted to
+ /// have the actual offset from the stack/frame pointer. The calculation is
+ /// MFI->getObjectOffset(Index) + StackSize - TFI.getOffsetOfLocalArea() +
+ /// OffsetAdjustment. If OffsetAdjustment is zero (default) then offsets are
+ /// away from TOS. If OffsetAdjustment == StackSize then offsets are toward
+ /// TOS.
+ int OffsetAdjustment;
+
+ /// MaxAlignment - The prolog/epilog code inserter may process objects
+ /// that require greater alignment than the default alignment the target
+ /// provides. To handle this, MaxAlignment is set to the maximum alignment
+ /// needed by the objects on the current frame. If this is greater than the
+ /// native alignment maintained by the compiler, dynamic alignment code will
+ /// be needed.
+ ///
+ unsigned MaxAlignment;
/// HasCalls - Set to true if this function has any function calls. This is
/// only valid during and after prolog/epilog code insertion.
/// insertion.
///
unsigned MaxCallFrameSize;
+
+ /// CSInfo - The prolog/epilog code inserter fills in this vector with each
+ /// callee saved register saved in the frame. Beyond its use by the prolog/
+ /// epilog code inserter, this data used for debug info and exception
+ /// handling.
+ std::vector<CalleeSavedInfo> CSInfo;
+
+ /// MMI - This field is set (via setMachineModuleInfo) by a module info
+ /// consumer (ex. DwarfWriter) to indicate that frame layout information
+ /// should be acquired. Typically, it's the responsibility of the target's
+ /// MRegisterInfo prologue/epilogue emitting code to inform MachineModuleInfo
+ /// of frame layouts.
+ MachineModuleInfo *MMI;
+
public:
- FunctionFrameInfo() {
- NumFixedObjects = StackSize = 0;
+ MachineFrameInfo() {
+ StackSize = NumFixedObjects = OffsetAdjustment = MaxAlignment = 0;
HasVarSizedObjects = false;
HasCalls = false;
MaxCallFrameSize = 0;
+ MMI = 0;
}
/// hasStackObjects - Return true if there are any stack objects in this
/// getObjectSize - Return the size of the specified object
///
- int getObjectSize(int ObjectIdx) const {
+ int64_t getObjectSize(int ObjectIdx) const {
assert(ObjectIdx+NumFixedObjects < Objects.size() && "Invalid Object Idx!");
return Objects[ObjectIdx+NumFixedObjects].Size;
}
/// getObjectOffset - Return the assigned stack offset of the specified object
/// from the incoming stack pointer.
///
- int getObjectOffset(int ObjectIdx) const {
+ int64_t getObjectOffset(int ObjectIdx) const {
assert(ObjectIdx+NumFixedObjects < Objects.size() && "Invalid Object Idx!");
return Objects[ObjectIdx+NumFixedObjects].SPOffset;
}
/// setObjectOffset - Set the stack frame offset of the specified object. The
/// offset is relative to the stack pointer on entry to the function.
///
- void setObjectOffset(int ObjectIdx, int SPOffset) {
+ void setObjectOffset(int ObjectIdx, int64_t SPOffset) {
assert(ObjectIdx+NumFixedObjects < Objects.size() && "Invalid Object Idx!");
Objects[ObjectIdx+NumFixedObjects].SPOffset = SPOffset;
}
/// all of the fixed size frame objects. This is only valid after
/// Prolog/Epilog code insertion has finalized the stack frame layout.
///
- unsigned getStackSize() const { return StackSize; }
+ uint64_t getStackSize() const { return StackSize; }
/// setStackSize - Set the size of the stack...
///
- void setStackSize(unsigned Size) { StackSize = Size; }
+ void setStackSize(uint64_t Size) { StackSize = Size; }
+
+ /// getOffsetAdjustment - Return the correction for frame offsets.
+ ///
+ int getOffsetAdjustment() const { return OffsetAdjustment; }
+
+ /// setOffsetAdjustment - Set the correction for frame offsets.
+ ///
+ void setOffsetAdjustment(int Adj) { OffsetAdjustment = Adj; }
+ /// getMaxAlignment - Return the alignment in bytes that this function must be
+ /// aligned to, which is greater than the default stack alignment provided by
+ /// the target.
+ ///
+ unsigned getMaxAlignment() const { return MaxAlignment; }
+
+ /// setMaxAlignment - Set the preferred alignment.
+ ///
+ void setMaxAlignment(unsigned Align) { MaxAlignment = Align; }
+
/// hasCalls - Return true if the current function has no function calls.
/// This is only valid during or after prolog/epilog code emission.
///
bool hasCalls() const { return HasCalls; }
void setHasCalls(bool V) { HasCalls = V; }
-
+
/// getMaxCallFrameSize - Return the maximum size of a call frame that must be
/// allocated for an outgoing function call. This is only available if
/// CallFrameSetup/Destroy pseudo instructions are used by the target, and
/// All fixed objects should be created before other objects are created for
/// efficiency. This returns an index with a negative value.
///
- int CreateFixedObject(unsigned Size, int SPOffset) {
+ int CreateFixedObject(uint64_t Size, int64_t SPOffset) {
assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset));
return -++NumFixedObjects;
}
-
+
+ /// isFixedObjectIndex - Returns true if the specified index corresponds to a
+ /// fixed stack object.
+ bool isFixedObjectIndex(int ObjectIdx) const {
+ return ObjectIdx < 0 && (ObjectIdx >= -(int)NumFixedObjects);
+ }
+
/// CreateStackObject - Create a new statically sized stack object, returning
/// a postive identifier to represent it.
///
- int CreateStackObject(unsigned Size, unsigned Alignment) {
+ int CreateStackObject(uint64_t Size, unsigned Alignment) {
+ // Keep track of the maximum alignment.
+ if (MaxAlignment < Alignment) MaxAlignment = Alignment;
+
assert(Size != 0 && "Cannot allocate zero size stack objects!");
Objects.push_back(StackObject(Size, Alignment, -1));
return Objects.size()-NumFixedObjects-1;
}
- /// CreateVariableSizedObject - Notify the FunctionFrameInfo object that a
+ /// CreateVariableSizedObject - Notify the MachineFrameInfo object that a
/// variable sized object has been created. This must be created whenever a
/// variable sized object is created, whether or not the index returned is
/// actually used.
///
int CreateVariableSizedObject() {
HasVarSizedObjects = true;
+ if (MaxAlignment < 1) MaxAlignment = 1;
Objects.push_back(StackObject(0, 1, -1));
return Objects.size()-NumFixedObjects-1;
}
+
+ /// getCalleeSavedInfo - Returns a reference to call saved info vector for the
+ /// current function.
+ const std::vector<CalleeSavedInfo> &getCalleeSavedInfo() const {
+ return CSInfo;
+ }
+
+ /// setCalleeSavedInfo - Used by prolog/epilog inserter to set the function's
+ /// callee saved information.
+ void setCalleeSavedInfo(const std::vector<CalleeSavedInfo> &CSI) {
+ CSInfo = CSI;
+ }
+
+ /// getMachineModuleInfo - Used by a prologue/epilogue emitter (MRegisterInfo)
+ /// to provide frame layout information.
+ MachineModuleInfo *getMachineModuleInfo() const { return MMI; }
+
+ /// setMachineModuleInfo - Used by a meta info consumer (DwarfWriter) to
+ /// indicate that frame layout information should be gathered.
+ void setMachineModuleInfo(MachineModuleInfo *mmi) { MMI = mmi; }
/// print - Used by the MachineFunction printer to print information about
/// stack objects. Implemented in MachineFunction.cpp
///
- void print(std::ostream &OS) const;
+ void print(const MachineFunction &MF, std::ostream &OS) const;
- /// dump - Call print(std::cerr) to be called from the debugger.
- void dump() const;
+ /// dump - Call print(MF, std::cerr) to be called from the debugger.
+ void dump(const MachineFunction &MF) const;
};
+} // End llvm namespace
+
#endif
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