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Diffstat (limited to 'lib/Target/Blackfin/BlackfinFrameInfo.cpp')
-rw-r--r-- | lib/Target/Blackfin/BlackfinFrameInfo.cpp | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/lib/Target/Blackfin/BlackfinFrameInfo.cpp b/lib/Target/Blackfin/BlackfinFrameInfo.cpp new file mode 100644 index 0000000..83f28b0 --- /dev/null +++ b/lib/Target/Blackfin/BlackfinFrameInfo.cpp @@ -0,0 +1,97 @@ +//====- BlackfinFrameInfo.cpp - Blackfin Frame Information ------*- 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 the Blackfin implementation of TargetFrameInfo class. +// +//===----------------------------------------------------------------------===// + +#include "BlackfinFrameInfo.h" +#include "BlackfinInstrInfo.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineInstrBuilder.h" + +using namespace llvm; + + +// Emit a prologue that sets up a stack frame. +// On function entry, R0-R2 and P0 may hold arguments. +// R3, P1, and P2 may be used as scratch registers +void BlackfinFrameInfo::emitPrologue(MachineFunction &MF) const { + MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB + MachineBasicBlock::iterator MBBI = MBB.begin(); + MachineFrameInfo *MFI = MF.getFrameInfo(); + const BlackfinRegisterInfo *RegInfo = + static_cast<const BlackfinRegisterInfo*>(MF.getTarget().getRegisterInfo()); + const BlackfinInstrInfo &TII = + *static_cast<const BlackfinInstrInfo*>(MF.getTarget().getInstrInfo()); + + DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc(); + + int FrameSize = MFI->getStackSize(); + if (FrameSize%4) { + FrameSize = (FrameSize+3) & ~3; + MFI->setStackSize(FrameSize); + } + + if (!RegInfo->hasFP(MF)) { + assert(!MFI->adjustsStack() && + "FP elimination on a non-leaf function is not supported"); + RegInfo->adjustRegister(MBB, MBBI, dl, BF::SP, BF::P1, -FrameSize); + return; + } + + // emit a LINK instruction + if (FrameSize <= 0x3ffff) { + BuildMI(MBB, MBBI, dl, TII.get(BF::LINK)).addImm(FrameSize); + return; + } + + // Frame is too big, do a manual LINK: + // [--SP] = RETS; + // [--SP] = FP; + // FP = SP; + // P1 = -FrameSize; + // SP = SP + P1; + BuildMI(MBB, MBBI, dl, TII.get(BF::PUSH)) + .addReg(BF::RETS, RegState::Kill); + BuildMI(MBB, MBBI, dl, TII.get(BF::PUSH)) + .addReg(BF::FP, RegState::Kill); + BuildMI(MBB, MBBI, dl, TII.get(BF::MOVE), BF::FP) + .addReg(BF::SP); + RegInfo->loadConstant(MBB, MBBI, dl, BF::P1, -FrameSize); + BuildMI(MBB, MBBI, dl, TII.get(BF::ADDpp), BF::SP) + .addReg(BF::SP, RegState::Kill) + .addReg(BF::P1, RegState::Kill); + +} + +void BlackfinFrameInfo::emitEpilogue(MachineFunction &MF, + MachineBasicBlock &MBB) const { + MachineFrameInfo *MFI = MF.getFrameInfo(); + const BlackfinRegisterInfo *RegInfo = + static_cast<const BlackfinRegisterInfo*>(MF.getTarget().getRegisterInfo()); + const BlackfinInstrInfo &TII = + *static_cast<const BlackfinInstrInfo*>(MF.getTarget().getInstrInfo()); + MachineBasicBlock::iterator MBBI = prior(MBB.end()); + DebugLoc dl = MBBI->getDebugLoc(); + + int FrameSize = MFI->getStackSize(); + assert(FrameSize%4 == 0 && "Misaligned frame size"); + + if (!RegInfo->hasFP(MF)) { + assert(!MFI->adjustsStack() && + "FP elimination on a non-leaf function is not supported"); + RegInfo->adjustRegister(MBB, MBBI, dl, BF::SP, BF::P1, FrameSize); + return; + } + + // emit an UNLINK instruction + BuildMI(MBB, MBBI, dl, TII.get(BF::UNLINK)); +} |