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llvm-mirror/lib/Target/PowerPC/PPCMachineFunctionInfo.h
Arnold Schwaighofer f58a35e2ec Tail call optimization improvements:
Move platform independent code (lowering of possibly overwritten
arguments, check for tail call optimization eligibility) from
target X86ISelectionLowering.cpp to TargetLowering.h and
SelectionDAGISel.cpp.

Initial PowerPC tail call implementation:

Support ppc32 implemented and tested (passes my tests and
test-suite llvm-test).  
Support ppc64 implemented and half tested (passes my tests).
On ppc tail call optimization is performed if 
  caller and callee are fastcc
  call is a tail call (in tail call position, call followed by ret)
  no variable argument lists or byval arguments
  option -tailcallopt is enabled
Supported:
 * non pic tail calls on linux/darwin
 * module-local tail calls on linux(PIC/GOT)/darwin(PIC)
 * inter-module tail calls on darwin(PIC)
If constraints are not met a normal call will be emitted.

A test checking the argument lowering behaviour on x86-64 was added.

llvm-svn: 50477
2008-04-30 09:16:33 +00:00

103 lines
3.8 KiB
C++

//===-- PPCMachineFunctionInfo.h - Private data used for PowerPC --*- C++ -*-=//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares the PowerPC specific subclass of MachineFunctionInfo.
//
//===----------------------------------------------------------------------===//
#ifndef PPC_MACHINE_FUNCTION_INFO_H
#define PPC_MACHINE_FUNCTION_INFO_H
#include "llvm/CodeGen/MachineFunction.h"
namespace llvm {
/// PPCFunctionInfo - This class is derived from MachineFunction private
/// PowerPC target-specific information for each MachineFunction.
class PPCFunctionInfo : public MachineFunctionInfo {
private:
/// FramePointerSaveIndex - Frame index of where the old frame pointer is
/// stored. Also used as an anchor for instructions that need to be altered
/// when using frame pointers (dyna_add, dyna_sub.)
int FramePointerSaveIndex;
/// ReturnAddrSaveIndex - Frame index of where the return address is stored.
///
int ReturnAddrSaveIndex;
/// UsesLR - Indicates whether LR is used in the current function. This is
/// only valid after the initial scan of the function by PEI.
bool UsesLR;
/// SpillsCR - Indicates whether CR is spilled in the current function.
bool SpillsCR;
/// LRStoreRequired - The bool indicates whether there is some explicit use of
/// the LR/LR8 stack slot that is not obvious from scanning the code. This
/// requires that the code generator produce a store of LR to the stack on
/// entry, even though LR may otherwise apparently not be used.
bool LRStoreRequired;
/// MinReservedArea - This is the frame size that is at least reserved in a
/// potential caller (parameter+linkage area).
unsigned MinReservedArea;
/// TailCallSPDelta - Stack pointer delta used when tail calling. Maximum
/// amount the stack pointer is adjusted to make the frame bigger for tail
/// calls. Used for creating an area before the register spill area.
int TailCallSPDelta;
/// HasFastCall - Does this function contain a fast call. Used to determine
/// how the caller's stack pointer should be calculated (epilog/dynamicalloc).
bool HasFastCall;
public:
PPCFunctionInfo(MachineFunction &MF)
: FramePointerSaveIndex(0),
ReturnAddrSaveIndex(0),
SpillsCR(false),
LRStoreRequired(false),
MinReservedArea(0),
TailCallSPDelta(0),
HasFastCall(false) {}
int getFramePointerSaveIndex() const { return FramePointerSaveIndex; }
void setFramePointerSaveIndex(int Idx) { FramePointerSaveIndex = Idx; }
int getReturnAddrSaveIndex() const { return ReturnAddrSaveIndex; }
void setReturnAddrSaveIndex(int idx) { ReturnAddrSaveIndex = idx; }
unsigned getMinReservedArea() const { return MinReservedArea; }
void setMinReservedArea(unsigned size) { MinReservedArea = size; }
int getTailCallSPDelta() const { return TailCallSPDelta; }
void setTailCallSPDelta(int size) { TailCallSPDelta = size; }
/// UsesLR - This is set when the prolog/epilog inserter does its initial scan
/// of the function, it is true if the LR/LR8 register is ever explicitly
/// accessed/clobbered in the machine function (e.g. by calls and movpctolr,
/// which is used in PIC generation).
void setUsesLR(bool U) { UsesLR = U; }
bool usesLR() const { return UsesLR; }
void setSpillsCR() { SpillsCR = true; }
bool isCRSpilled() const { return SpillsCR; }
void setLRStoreRequired() { LRStoreRequired = true; }
bool isLRStoreRequired() const { return LRStoreRequired; }
void setHasFastCall() { HasFastCall = true; }
bool hasFastCall() const { return HasFastCall;}
};
} // end of namespace llvm
#endif