diff options
Diffstat (limited to 'contrib/llvm/lib/Target/Sparc/SparcFrameLowering.cpp')
| -rw-r--r-- | contrib/llvm/lib/Target/Sparc/SparcFrameLowering.cpp | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/Sparc/SparcFrameLowering.cpp b/contrib/llvm/lib/Target/Sparc/SparcFrameLowering.cpp new file mode 100644 index 0000000..c0279da --- /dev/null +++ b/contrib/llvm/lib/Target/Sparc/SparcFrameLowering.cpp @@ -0,0 +1,261 @@ +//===-- SparcFrameLowering.cpp - Sparc Frame Information ------------------===// +// +// 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 Sparc implementation of TargetFrameLowering class. +// +//===----------------------------------------------------------------------===// + +#include "SparcFrameLowering.h" +#include "SparcInstrInfo.h" +#include "SparcMachineFunctionInfo.h" +#include "SparcSubtarget.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/IR/DataLayout.h" +#include "llvm/IR/Function.h" +#include "llvm/Support/CommandLine.h" +#include "llvm/Target/TargetOptions.h" + +using namespace llvm; + +static cl::opt<bool> +DisableLeafProc("disable-sparc-leaf-proc", + cl::init(false), + cl::desc("Disable Sparc leaf procedure optimization."), + cl::Hidden); + +SparcFrameLowering::SparcFrameLowering(const SparcSubtarget &ST) + : TargetFrameLowering(TargetFrameLowering::StackGrowsDown, + ST.is64Bit() ? 16 : 8, 0, ST.is64Bit() ? 16 : 8) {} + +void SparcFrameLowering::emitSPAdjustment(MachineFunction &MF, + MachineBasicBlock &MBB, + MachineBasicBlock::iterator MBBI, + int NumBytes, + unsigned ADDrr, + unsigned ADDri) const { + + DebugLoc dl = (MBBI != MBB.end()) ? MBBI->getDebugLoc() : DebugLoc(); + const SparcInstrInfo &TII = + *static_cast<const SparcInstrInfo *>(MF.getSubtarget().getInstrInfo()); + + if (NumBytes >= -4096 && NumBytes < 4096) { + BuildMI(MBB, MBBI, dl, TII.get(ADDri), SP::O6) + .addReg(SP::O6).addImm(NumBytes); + return; + } + + // Emit this the hard way. This clobbers G1 which we always know is + // available here. + if (NumBytes >= 0) { + // Emit nonnegative numbers with sethi + or. + // sethi %hi(NumBytes), %g1 + // or %g1, %lo(NumBytes), %g1 + // add %sp, %g1, %sp + BuildMI(MBB, MBBI, dl, TII.get(SP::SETHIi), SP::G1) + .addImm(HI22(NumBytes)); + BuildMI(MBB, MBBI, dl, TII.get(SP::ORri), SP::G1) + .addReg(SP::G1).addImm(LO10(NumBytes)); + BuildMI(MBB, MBBI, dl, TII.get(ADDrr), SP::O6) + .addReg(SP::O6).addReg(SP::G1); + return ; + } + + // Emit negative numbers with sethi + xor. + // sethi %hix(NumBytes), %g1 + // xor %g1, %lox(NumBytes), %g1 + // add %sp, %g1, %sp + BuildMI(MBB, MBBI, dl, TII.get(SP::SETHIi), SP::G1) + .addImm(HIX22(NumBytes)); + BuildMI(MBB, MBBI, dl, TII.get(SP::XORri), SP::G1) + .addReg(SP::G1).addImm(LOX10(NumBytes)); + BuildMI(MBB, MBBI, dl, TII.get(ADDrr), SP::O6) + .addReg(SP::O6).addReg(SP::G1); +} + +void SparcFrameLowering::emitPrologue(MachineFunction &MF, + MachineBasicBlock &MBB) const { + SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>(); + + assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported"); + MachineFrameInfo *MFI = MF.getFrameInfo(); + const SparcInstrInfo &TII = + *static_cast<const SparcInstrInfo *>(MF.getSubtarget().getInstrInfo()); + MachineBasicBlock::iterator MBBI = MBB.begin(); + DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc(); + + // Get the number of bytes to allocate from the FrameInfo + int NumBytes = (int) MFI->getStackSize(); + + unsigned SAVEri = SP::SAVEri; + unsigned SAVErr = SP::SAVErr; + if (FuncInfo->isLeafProc()) { + if (NumBytes == 0) + return; + SAVEri = SP::ADDri; + SAVErr = SP::ADDrr; + } + NumBytes = -MF.getSubtarget<SparcSubtarget>().getAdjustedFrameSize(NumBytes); + emitSPAdjustment(MF, MBB, MBBI, NumBytes, SAVErr, SAVEri); + + MachineModuleInfo &MMI = MF.getMMI(); + const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo(); + unsigned regFP = MRI->getDwarfRegNum(SP::I6, true); + + // Emit ".cfi_def_cfa_register 30". + unsigned CFIIndex = + MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(nullptr, regFP)); + BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION)) + .addCFIIndex(CFIIndex); + + // Emit ".cfi_window_save". + CFIIndex = MMI.addFrameInst(MCCFIInstruction::createWindowSave(nullptr)); + BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION)) + .addCFIIndex(CFIIndex); + + unsigned regInRA = MRI->getDwarfRegNum(SP::I7, true); + unsigned regOutRA = MRI->getDwarfRegNum(SP::O7, true); + // Emit ".cfi_register 15, 31". + CFIIndex = MMI.addFrameInst( + MCCFIInstruction::createRegister(nullptr, regOutRA, regInRA)); + BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION)) + .addCFIIndex(CFIIndex); +} + +void SparcFrameLowering:: +eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, + MachineBasicBlock::iterator I) const { + if (!hasReservedCallFrame(MF)) { + MachineInstr &MI = *I; + int Size = MI.getOperand(0).getImm(); + if (MI.getOpcode() == SP::ADJCALLSTACKDOWN) + Size = -Size; + + if (Size) + emitSPAdjustment(MF, MBB, I, Size, SP::ADDrr, SP::ADDri); + } + MBB.erase(I); +} + + +void SparcFrameLowering::emitEpilogue(MachineFunction &MF, + MachineBasicBlock &MBB) const { + SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>(); + MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr(); + const SparcInstrInfo &TII = + *static_cast<const SparcInstrInfo *>(MF.getSubtarget().getInstrInfo()); + DebugLoc dl = MBBI->getDebugLoc(); + assert(MBBI->getOpcode() == SP::RETL && + "Can only put epilog before 'retl' instruction!"); + if (!FuncInfo->isLeafProc()) { + BuildMI(MBB, MBBI, dl, TII.get(SP::RESTORErr), SP::G0).addReg(SP::G0) + .addReg(SP::G0); + return; + } + MachineFrameInfo *MFI = MF.getFrameInfo(); + + int NumBytes = (int) MFI->getStackSize(); + if (NumBytes == 0) + return; + + NumBytes = MF.getSubtarget<SparcSubtarget>().getAdjustedFrameSize(NumBytes); + emitSPAdjustment(MF, MBB, MBBI, NumBytes, SP::ADDrr, SP::ADDri); +} + +bool SparcFrameLowering::hasReservedCallFrame(const MachineFunction &MF) const { + // Reserve call frame if there are no variable sized objects on the stack. + return !MF.getFrameInfo()->hasVarSizedObjects(); +} + +// hasFP - Return true if the specified function should have a dedicated frame +// pointer register. This is true if the function has variable sized allocas or +// if frame pointer elimination is disabled. +bool SparcFrameLowering::hasFP(const MachineFunction &MF) const { + const MachineFrameInfo *MFI = MF.getFrameInfo(); + return MF.getTarget().Options.DisableFramePointerElim(MF) || + MFI->hasVarSizedObjects() || MFI->isFrameAddressTaken(); +} + + +static bool LLVM_ATTRIBUTE_UNUSED verifyLeafProcRegUse(MachineRegisterInfo *MRI) +{ + + for (unsigned reg = SP::I0; reg <= SP::I7; ++reg) + if (MRI->isPhysRegUsed(reg)) + return false; + + for (unsigned reg = SP::L0; reg <= SP::L7; ++reg) + if (MRI->isPhysRegUsed(reg)) + return false; + + return true; +} + +bool SparcFrameLowering::isLeafProc(MachineFunction &MF) const +{ + + MachineRegisterInfo &MRI = MF.getRegInfo(); + MachineFrameInfo *MFI = MF.getFrameInfo(); + + return !(MFI->hasCalls() // has calls + || MRI.isPhysRegUsed(SP::L0) // Too many registers needed + || MRI.isPhysRegUsed(SP::O6) // %SP is used + || hasFP(MF)); // need %FP +} + +void SparcFrameLowering::remapRegsForLeafProc(MachineFunction &MF) const { + + MachineRegisterInfo &MRI = MF.getRegInfo(); + + // Remap %i[0-7] to %o[0-7]. + for (unsigned reg = SP::I0; reg <= SP::I7; ++reg) { + if (!MRI.isPhysRegUsed(reg)) + continue; + unsigned mapped_reg = (reg - SP::I0 + SP::O0); + assert(!MRI.isPhysRegUsed(mapped_reg)); + + // Replace I register with O register. + MRI.replaceRegWith(reg, mapped_reg); + + // Mark the reg unused. + MRI.setPhysRegUnused(reg); + } + + // Rewrite MBB's Live-ins. + for (MachineFunction::iterator MBB = MF.begin(), E = MF.end(); + MBB != E; ++MBB) { + for (unsigned reg = SP::I0; reg <= SP::I7; ++reg) { + if (!MBB->isLiveIn(reg)) + continue; + MBB->removeLiveIn(reg); + MBB->addLiveIn(reg - SP::I0 + SP::O0); + } + } + + assert(verifyLeafProcRegUse(&MRI)); +#ifdef XDEBUG + MF.verify(0, "After LeafProc Remapping"); +#endif +} + +void SparcFrameLowering::determineCalleeSaves(MachineFunction &MF, + BitVector &SavedRegs, + RegScavenger *RS) const { + TargetFrameLowering::determineCalleeSaves(MF, SavedRegs, RS); + if (!DisableLeafProc && isLeafProc(MF)) { + SparcMachineFunctionInfo *MFI = MF.getInfo<SparcMachineFunctionInfo>(); + MFI->setLeafProc(true); + + remapRegsForLeafProc(MF); + } + +} |
