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Diffstat (limited to 'contrib/llvm/lib/Target/CellSPU/SPUFrameLowering.cpp')
| -rw-r--r-- | contrib/llvm/lib/Target/CellSPU/SPUFrameLowering.cpp | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/CellSPU/SPUFrameLowering.cpp b/contrib/llvm/lib/Target/CellSPU/SPUFrameLowering.cpp new file mode 100644 index 0000000..432f4a1 --- /dev/null +++ b/contrib/llvm/lib/Target/CellSPU/SPUFrameLowering.cpp @@ -0,0 +1,276 @@ +//===-- SPUTargetMachine.cpp - Define TargetMachine for Cell SPU ----------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// Top-level implementation for the Cell SPU target. +// +//===----------------------------------------------------------------------===// + +#include "SPU.h" +#include "SPUFrameLowering.h" +#include "SPURegisterNames.h" +#include "SPUInstrBuilder.h" +#include "SPUInstrInfo.h" +#include "llvm/Function.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineInstrBuilder.h" +#include "llvm/CodeGen/MachineModuleInfo.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/CodeGen/RegisterScavenging.h" +#include "llvm/Target/TargetData.h" +#include "llvm/Target/TargetOptions.h" +#include "llvm/Support/CommandLine.h" +using namespace llvm; + +//===----------------------------------------------------------------------===// +// SPUFrameLowering: +//===----------------------------------------------------------------------===// + +SPUFrameLowering::SPUFrameLowering(const SPUSubtarget &sti) + : TargetFrameLowering(TargetFrameLowering::StackGrowsDown, 16, 0), + Subtarget(sti) { + LR[0].first = SPU::R0; + LR[0].second = 16; +} + + +//-------------------------------------------------------------------------- +// hasFP - Return true if the specified function actually has a dedicated frame +// pointer register. This is true if the function needs a frame pointer and has +// a non-zero stack size. +bool SPUFrameLowering::hasFP(const MachineFunction &MF) const { + const MachineFrameInfo *MFI = MF.getFrameInfo(); + + return MFI->getStackSize() && + (DisableFramePointerElim(MF) || MFI->hasVarSizedObjects()); +} + + +/// determineFrameLayout - Determine the size of the frame and maximum call +/// frame size. +void SPUFrameLowering::determineFrameLayout(MachineFunction &MF) const { + MachineFrameInfo *MFI = MF.getFrameInfo(); + + // Get the number of bytes to allocate from the FrameInfo + unsigned FrameSize = MFI->getStackSize(); + + // Get the alignments provided by the target, and the maximum alignment + // (if any) of the fixed frame objects. + unsigned TargetAlign = getStackAlignment(); + unsigned Align = std::max(TargetAlign, MFI->getMaxAlignment()); + assert(isPowerOf2_32(Align) && "Alignment is not power of 2"); + unsigned AlignMask = Align - 1; + + // Get the maximum call frame size of all the calls. + unsigned maxCallFrameSize = MFI->getMaxCallFrameSize(); + + // If we have dynamic alloca then maxCallFrameSize needs to be aligned so + // that allocations will be aligned. + if (MFI->hasVarSizedObjects()) + maxCallFrameSize = (maxCallFrameSize + AlignMask) & ~AlignMask; + + // Update maximum call frame size. + MFI->setMaxCallFrameSize(maxCallFrameSize); + + // Include call frame size in total. + FrameSize += maxCallFrameSize; + + // Make sure the frame is aligned. + FrameSize = (FrameSize + AlignMask) & ~AlignMask; + + // Update frame info. + MFI->setStackSize(FrameSize); +} + +void SPUFrameLowering::emitPrologue(MachineFunction &MF) const { + MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB + MachineBasicBlock::iterator MBBI = MBB.begin(); + MachineFrameInfo *MFI = MF.getFrameInfo(); + const SPUInstrInfo &TII = + *static_cast<const SPUInstrInfo*>(MF.getTarget().getInstrInfo()); + MachineModuleInfo &MMI = MF.getMMI(); + DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc(); + + // Prepare for debug frame info. + bool hasDebugInfo = MMI.hasDebugInfo(); + MCSymbol *FrameLabel = 0; + + // Move MBBI back to the beginning of the function. + MBBI = MBB.begin(); + + // Work out frame sizes. + determineFrameLayout(MF); + int FrameSize = MFI->getStackSize(); + + assert((FrameSize & 0xf) == 0 + && "SPURegisterInfo::emitPrologue: FrameSize not aligned"); + + // the "empty" frame size is 16 - just the register scavenger spill slot + if (FrameSize > 16 || MFI->adjustsStack()) { + FrameSize = -(FrameSize + SPUFrameLowering::minStackSize()); + if (hasDebugInfo) { + // Mark effective beginning of when frame pointer becomes valid. + FrameLabel = MMI.getContext().CreateTempSymbol(); + BuildMI(MBB, MBBI, dl, TII.get(SPU::PROLOG_LABEL)).addSym(FrameLabel); + } + + // Adjust stack pointer, spilling $lr -> 16($sp) and $sp -> -FrameSize($sp) + // for the ABI + BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr32), SPU::R0).addImm(16) + .addReg(SPU::R1); + if (isInt<10>(FrameSize)) { + // Spill $sp to adjusted $sp + BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr32), SPU::R1).addImm(FrameSize) + .addReg(SPU::R1); + // Adjust $sp by required amout + BuildMI(MBB, MBBI, dl, TII.get(SPU::AIr32), SPU::R1).addReg(SPU::R1) + .addImm(FrameSize); + } else if (isInt<16>(FrameSize)) { + // Frame size can be loaded into ILr32n, so temporarily spill $r2 and use + // $r2 to adjust $sp: + BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr128), SPU::R2) + .addImm(-16) + .addReg(SPU::R1); + BuildMI(MBB, MBBI, dl, TII.get(SPU::ILr32), SPU::R2) + .addImm(FrameSize); + BuildMI(MBB, MBBI, dl, TII.get(SPU::STQXr32), SPU::R1) + .addReg(SPU::R2) + .addReg(SPU::R1); + BuildMI(MBB, MBBI, dl, TII.get(SPU::Ar32), SPU::R1) + .addReg(SPU::R1) + .addReg(SPU::R2); + BuildMI(MBB, MBBI, dl, TII.get(SPU::SFIr32), SPU::R2) + .addReg(SPU::R2) + .addImm(16); + BuildMI(MBB, MBBI, dl, TII.get(SPU::LQXr128), SPU::R2) + .addReg(SPU::R2) + .addReg(SPU::R1); + } else { + report_fatal_error("Unhandled frame size: " + Twine(FrameSize)); + } + + if (hasDebugInfo) { + std::vector<MachineMove> &Moves = MMI.getFrameMoves(); + + // Show update of SP. + MachineLocation SPDst(MachineLocation::VirtualFP); + MachineLocation SPSrc(MachineLocation::VirtualFP, -FrameSize); + Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc)); + + // Add callee saved registers to move list. + const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo(); + for (unsigned I = 0, E = CSI.size(); I != E; ++I) { + int Offset = MFI->getObjectOffset(CSI[I].getFrameIdx()); + unsigned Reg = CSI[I].getReg(); + if (Reg == SPU::R0) continue; + MachineLocation CSDst(MachineLocation::VirtualFP, Offset); + MachineLocation CSSrc(Reg); + Moves.push_back(MachineMove(FrameLabel, CSDst, CSSrc)); + } + + // Mark effective beginning of when frame pointer is ready. + MCSymbol *ReadyLabel = MMI.getContext().CreateTempSymbol(); + BuildMI(MBB, MBBI, dl, TII.get(SPU::PROLOG_LABEL)).addSym(ReadyLabel); + + MachineLocation FPDst(SPU::R1); + MachineLocation FPSrc(MachineLocation::VirtualFP); + Moves.push_back(MachineMove(ReadyLabel, FPDst, FPSrc)); + } + } else { + // This is a leaf function -- insert a branch hint iff there are + // sufficient number instructions in the basic block. Note that + // this is just a best guess based on the basic block's size. + if (MBB.size() >= (unsigned) SPUFrameLowering::branchHintPenalty()) { + MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr(); + dl = MBBI->getDebugLoc(); + + // Insert terminator label + BuildMI(MBB, MBBI, dl, TII.get(SPU::PROLOG_LABEL)) + .addSym(MMI.getContext().CreateTempSymbol()); + } + } +} + +void SPUFrameLowering::emitEpilogue(MachineFunction &MF, + MachineBasicBlock &MBB) const { + MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr(); + const SPUInstrInfo &TII = + *static_cast<const SPUInstrInfo*>(MF.getTarget().getInstrInfo()); + const MachineFrameInfo *MFI = MF.getFrameInfo(); + int FrameSize = MFI->getStackSize(); + int LinkSlotOffset = SPUFrameLowering::stackSlotSize(); + DebugLoc dl = MBBI->getDebugLoc(); + + assert(MBBI->getOpcode() == SPU::RET && + "Can only insert epilog into returning blocks"); + assert((FrameSize & 0xf) == 0 && "FrameSize not aligned"); + + // the "empty" frame size is 16 - just the register scavenger spill slot + if (FrameSize > 16 || MFI->adjustsStack()) { + FrameSize = FrameSize + SPUFrameLowering::minStackSize(); + if (isInt<10>(FrameSize + LinkSlotOffset)) { + // Reload $lr, adjust $sp by required amount + // Note: We do this to slightly improve dual issue -- not by much, but it + // is an opportunity for dual issue. + BuildMI(MBB, MBBI, dl, TII.get(SPU::LQDr128), SPU::R0) + .addImm(FrameSize + LinkSlotOffset) + .addReg(SPU::R1); + BuildMI(MBB, MBBI, dl, TII.get(SPU::AIr32), SPU::R1) + .addReg(SPU::R1) + .addImm(FrameSize); + } else if (FrameSize <= (1 << 16) - 1 && FrameSize >= -(1 << 16)) { + // Frame size can be loaded into ILr32n, so temporarily spill $r2 and use + // $r2 to adjust $sp: + BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr128), SPU::R2) + .addImm(16) + .addReg(SPU::R1); + BuildMI(MBB, MBBI, dl, TII.get(SPU::ILr32), SPU::R2) + .addImm(FrameSize); + BuildMI(MBB, MBBI, dl, TII.get(SPU::Ar32), SPU::R1) + .addReg(SPU::R1) + .addReg(SPU::R2); + BuildMI(MBB, MBBI, dl, TII.get(SPU::LQDr128), SPU::R0) + .addImm(16) + .addReg(SPU::R1); + BuildMI(MBB, MBBI, dl, TII.get(SPU::SFIr32), SPU::R2). + addReg(SPU::R2) + .addImm(16); + BuildMI(MBB, MBBI, dl, TII.get(SPU::LQXr128), SPU::R2) + .addReg(SPU::R2) + .addReg(SPU::R1); + } else { + report_fatal_error("Unhandled frame size: " + Twine(FrameSize)); + } + } +} + +void SPUFrameLowering::getInitialFrameState(std::vector<MachineMove> &Moves) + const { + // Initial state of the frame pointer is R1. + MachineLocation Dst(MachineLocation::VirtualFP); + MachineLocation Src(SPU::R1, 0); + Moves.push_back(MachineMove(0, Dst, Src)); +} + +void SPUFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF, + RegScavenger *RS) const{ + // Mark LR and SP unused, since the prolog spills them to stack and + // we don't want anyone else to spill them for us. + // + // Also, unless R2 is really used someday, don't spill it automatically. + MF.getRegInfo().setPhysRegUnused(SPU::R0); + MF.getRegInfo().setPhysRegUnused(SPU::R1); + MF.getRegInfo().setPhysRegUnused(SPU::R2); + + MachineFrameInfo *MFI = MF.getFrameInfo(); + const TargetRegisterClass *RC = &SPU::R32CRegClass; + RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(), + RC->getAlignment(), + false)); +} |
