llvm-6502/lib/Target/CellSPU/SPUFrameInfo.h
2007-12-29 20:36:04 +00:00

76 lines
2.4 KiB
C++

//===-- SPUFrameInfo.h - Top-level interface for Cell SPU Target -*- C++ -*-==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains CellSPU frame information that doesn't fit anywhere else
// cleanly...
//
//===----------------------------------------------------------------------===//
#if !defined(SPUFRAMEINFO_H)
#include "llvm/Target/TargetFrameInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "SPURegisterInfo.h"
namespace llvm {
class SPUFrameInfo: public TargetFrameInfo {
const TargetMachine &TM;
std::pair<unsigned, int> LR[1];
public:
SPUFrameInfo(const TargetMachine &tm);
//! Return a function's saved spill slots
/*!
For CellSPU, a function's saved spill slots is just the link register.
*/
const std::pair<unsigned, int> *
getCalleeSaveSpillSlots(unsigned &NumEntries) const;
//! Stack slot size (16 bytes)
static const int stackSlotSize() {
return 16;
}
//! Maximum frame offset representable by a signed 10-bit integer
/*!
This is the maximum frame offset that can be expressed as a 10-bit
integer, used in D-form addresses.
*/
static const int maxFrameOffset() {
return ((1 << 9) - 1) * stackSlotSize();
}
//! Minimum frame offset representable by a signed 10-bit integer
static const int minFrameOffset() {
return -(1 << 9) * stackSlotSize();
}
//! Minimum frame size (enough to spill LR + SP)
static const int minStackSize() {
return (2 * stackSlotSize());
}
//! Frame size required to spill all registers plus frame info
static const int fullSpillSize() {
return (SPURegisterInfo::getNumArgRegs() * stackSlotSize());
}
//! Number of instructions required to overcome hint-for-branch latency
/*!
HBR (hint-for-branch) instructions can be inserted when, for example,
we know that a given function is going to be called, such as printf(),
in the control flow graph. HBRs are only inserted if a sufficient number
of instructions occurs between the HBR and the target. Currently, HBRs
take 6 cycles, ergo, the magic number 6.
*/
static const int branchHintPenalty() {
return 6;
}
};
}
#define SPUFRAMEINFO_H 1
#endif