diff options
Diffstat (limited to 'contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp')
| -rw-r--r-- | contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp | 242 |
1 files changed, 155 insertions, 87 deletions
diff --git a/contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp b/contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp index 08ae717..beab844 100644 --- a/contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp +++ b/contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp @@ -30,7 +30,7 @@ using namespace llvm; /// VRRegNo - Map from a numbered VR register to its enum value. /// -static const uint16_t VRRegNo[] = { +static const MCPhysReg VRRegNo[] = { PPC::V0 , PPC::V1 , PPC::V2 , PPC::V3 , PPC::V4 , PPC::V5 , PPC::V6 , PPC::V7 , PPC::V8 , PPC::V9 , PPC::V10, PPC::V11, PPC::V12, PPC::V13, PPC::V14, PPC::V15, PPC::V16, PPC::V17, PPC::V18, PPC::V19, PPC::V20, PPC::V21, PPC::V22, PPC::V23, @@ -270,7 +270,7 @@ static void RemoveVRSaveCode(MachineInstr *MI) { // epilog blocks. for (MachineFunction::iterator I = MF->begin(), E = MF->end(); I != E; ++I) { // If last instruction is a return instruction, add an epilogue - if (!I->empty() && I->back().isReturn()) { + if (I->isReturnBlock()) { bool FoundIt = false; for (MBBI = I->end(); MBBI != I->begin(); ) { --MBBI; @@ -306,9 +306,10 @@ static void HandleVRSaveUpdate(MachineInstr *MI, const TargetInstrInfo &TII) { const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo(); DebugLoc dl = MI->getDebugLoc(); + const MachineRegisterInfo &MRI = MF->getRegInfo(); unsigned UsedRegMask = 0; for (unsigned i = 0; i != 32; ++i) - if (MF->getRegInfo().isPhysRegUsed(VRRegNo[i])) + if (MRI.isPhysRegModified(VRRegNo[i])) UsedRegMask |= 1 << (31-i); // Live in and live out values already must be in the mask, so don't bother @@ -325,7 +326,7 @@ static void HandleVRSaveUpdate(MachineInstr *MI, const TargetInstrInfo &TII) { for (MachineFunction::const_iterator BI = MF->begin(), BE = MF->end(); UsedRegMask != 0 && BI != BE; ++BI) { const MachineBasicBlock &MBB = *BI; - if (MBB.empty() || !MBB.back().isReturn()) + if (!MBB.isReturnBlock()) continue; const MachineInstr &Ret = MBB.back(); for (unsigned I = 0, E = Ret.getNumOperands(); I != E; ++I) { @@ -555,9 +556,67 @@ void PPCFrameLowering::replaceFPWithRealFP(MachineFunction &MF) const { } } +bool PPCFrameLowering::findScratchRegister(MachineBasicBlock *MBB, + bool UseAtEnd, + unsigned *ScratchRegister) const { + RegScavenger RS; + unsigned R0 = Subtarget.isPPC64() ? PPC::X0 : PPC::R0; + + if (ScratchRegister) + *ScratchRegister = R0; + + // If MBB is an entry or exit block, use R0 as the scratch register + if ((UseAtEnd && MBB->isReturnBlock()) || + (!UseAtEnd && (&MBB->getParent()->front() == MBB))) + return true; + + RS.enterBasicBlock(MBB); + + if (UseAtEnd && !MBB->empty()) { + // The scratch register will be used at the end of the block, so must consider + // all registers used within the block + + MachineBasicBlock::iterator MBBI = MBB->getFirstTerminator(); + // If no terminator, back iterator up to previous instruction. + if (MBBI == MBB->end()) + MBBI = std::prev(MBBI); + + if (MBBI != MBB->begin()) + RS.forward(MBBI); + } + + if (!RS.isRegUsed(R0)) + return true; + + unsigned Reg = RS.FindUnusedReg(Subtarget.isPPC64() ? &PPC::G8RCRegClass + : &PPC::GPRCRegClass); + + // Make sure the register scavenger was able to find an available register + // If not, use R0 but return false to indicate no register was available and + // R0 must be used (as recommended by the ABI) + if (Reg == 0) + return false; + + if (ScratchRegister) + *ScratchRegister = Reg; + + return true; +} + +bool PPCFrameLowering::canUseAsPrologue(const MachineBasicBlock &MBB) const { + MachineBasicBlock *TmpMBB = const_cast<MachineBasicBlock *>(&MBB); + + return findScratchRegister(TmpMBB, false, nullptr); +} + +bool PPCFrameLowering::canUseAsEpilogue(const MachineBasicBlock &MBB) const { + MachineBasicBlock *TmpMBB = const_cast<MachineBasicBlock *>(&MBB); + + return findScratchRegister(TmpMBB, true, nullptr); +} + void PPCFrameLowering::emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const { - assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported"); MachineBasicBlock::iterator MBBI = MBB.begin(); MachineFrameInfo *MFI = MF.getFrameInfo(); const PPCInstrInfo &TII = @@ -589,7 +648,7 @@ void PPCFrameLowering::emitPrologue(MachineFunction &MF, } } - // Move MBBI back to the beginning of the function. + // Move MBBI back to the beginning of the prologue block. MBBI = MBB.begin(); // Work out frame sizes. @@ -613,7 +672,7 @@ void PPCFrameLowering::emitPrologue(MachineFunction &MF, unsigned BPReg = RegInfo->getBaseRegister(MF); unsigned FPReg = isPPC64 ? PPC::X31 : PPC::R31; unsigned LRReg = isPPC64 ? PPC::LR8 : PPC::LR; - unsigned ScratchReg = isPPC64 ? PPC::X0 : PPC::R0; + unsigned ScratchReg = 0; unsigned TempReg = isPPC64 ? PPC::X12 : PPC::R12; // another scratch reg // ...(R12/X12 is volatile in both Darwin & SVR4, & can't be a function arg.) const MCInstrDesc& MFLRInst = TII.get(isPPC64 ? PPC::MFLR8 @@ -642,6 +701,9 @@ void PPCFrameLowering::emitPrologue(MachineFunction &MF, assert((isPPC64 || !isSVR4ABI || !(!FrameSize && (MustSaveLR || HasFP))) && "FrameSize must be >0 to save/restore the FP or LR for 32-bit SVR4."); + findScratchRegister(&MBB, false, &ScratchReg); + assert(ScratchReg && "No scratch register!"); + int LROffset = getReturnSaveOffset(); int FPOffset = 0; @@ -916,27 +978,18 @@ void PPCFrameLowering::emitPrologue(MachineFunction &MF, } void PPCFrameLowering::emitEpilogue(MachineFunction &MF, - MachineBasicBlock &MBB) const { - MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr(); - assert(MBBI != MBB.end() && "Returning block has no terminator"); + MachineBasicBlock &MBB) const { + MachineBasicBlock::iterator MBBI = MBB.getFirstTerminator(); + DebugLoc dl; + + if (MBBI != MBB.end()) + dl = MBBI->getDebugLoc(); + const PPCInstrInfo &TII = *static_cast<const PPCInstrInfo *>(Subtarget.getInstrInfo()); const PPCRegisterInfo *RegInfo = static_cast<const PPCRegisterInfo *>(Subtarget.getRegisterInfo()); - unsigned RetOpcode = MBBI->getOpcode(); - DebugLoc dl; - - assert((RetOpcode == PPC::BLR || - RetOpcode == PPC::BLR8 || - RetOpcode == PPC::TCRETURNri || - RetOpcode == PPC::TCRETURNdi || - RetOpcode == PPC::TCRETURNai || - RetOpcode == PPC::TCRETURNri8 || - RetOpcode == PPC::TCRETURNdi8 || - RetOpcode == PPC::TCRETURNai8) && - "Can only insert epilog into returning blocks"); - // Get alignment info so we know how to restore the SP. const MachineFrameInfo *MFI = MF.getFrameInfo(); @@ -959,7 +1012,7 @@ void PPCFrameLowering::emitEpilogue(MachineFunction &MF, unsigned SPReg = isPPC64 ? PPC::X1 : PPC::R1; unsigned BPReg = RegInfo->getBaseRegister(MF); unsigned FPReg = isPPC64 ? PPC::X31 : PPC::R31; - unsigned ScratchReg = isPPC64 ? PPC::X0 : PPC::R0; + unsigned ScratchReg = 0; unsigned TempReg = isPPC64 ? PPC::X12 : PPC::R12; // another scratch reg const MCInstrDesc& MTLRInst = TII.get( isPPC64 ? PPC::MTLR8 : PPC::MTLR ); @@ -973,10 +1026,14 @@ void PPCFrameLowering::emitEpilogue(MachineFunction &MF, : PPC::ADDI ); const MCInstrDesc& AddInst = TII.get( isPPC64 ? PPC::ADD8 : PPC::ADD4 ); - + int LROffset = getReturnSaveOffset(); int FPOffset = 0; + + findScratchRegister(&MBB, true, &ScratchReg); + assert(ScratchReg && "No scratch register!"); + if (HasFP) { if (isSVR4ABI) { MachineFrameInfo *FFI = MF.getFrameInfo(); @@ -1008,25 +1065,30 @@ void PPCFrameLowering::emitEpilogue(MachineFunction &MF, PBPOffset = FFI->getObjectOffset(PBPIndex); } - bool UsesTCRet = RetOpcode == PPC::TCRETURNri || - RetOpcode == PPC::TCRETURNdi || - RetOpcode == PPC::TCRETURNai || - RetOpcode == PPC::TCRETURNri8 || - RetOpcode == PPC::TCRETURNdi8 || - RetOpcode == PPC::TCRETURNai8; - - if (UsesTCRet) { - int MaxTCRetDelta = FI->getTailCallSPDelta(); - MachineOperand &StackAdjust = MBBI->getOperand(1); - assert(StackAdjust.isImm() && "Expecting immediate value."); - // Adjust stack pointer. - int StackAdj = StackAdjust.getImm(); - int Delta = StackAdj - MaxTCRetDelta; - assert((Delta >= 0) && "Delta must be positive"); - if (MaxTCRetDelta>0) - FrameSize += (StackAdj +Delta); - else - FrameSize += StackAdj; + bool IsReturnBlock = (MBBI != MBB.end() && MBBI->isReturn()); + + if (IsReturnBlock) { + unsigned RetOpcode = MBBI->getOpcode(); + bool UsesTCRet = RetOpcode == PPC::TCRETURNri || + RetOpcode == PPC::TCRETURNdi || + RetOpcode == PPC::TCRETURNai || + RetOpcode == PPC::TCRETURNri8 || + RetOpcode == PPC::TCRETURNdi8 || + RetOpcode == PPC::TCRETURNai8; + + if (UsesTCRet) { + int MaxTCRetDelta = FI->getTailCallSPDelta(); + MachineOperand &StackAdjust = MBBI->getOperand(1); + assert(StackAdjust.isImm() && "Expecting immediate value."); + // Adjust stack pointer. + int StackAdj = StackAdjust.getImm(); + int Delta = StackAdj - MaxTCRetDelta; + assert((Delta >= 0) && "Delta must be positive"); + if (MaxTCRetDelta>0) + FrameSize += (StackAdj +Delta); + else + FrameSize += StackAdj; + } } // Frames of 32KB & larger require special handling because they cannot be @@ -1066,7 +1128,6 @@ void PPCFrameLowering::emitEpilogue(MachineFunction &MF, .addImm(0) .addReg(SPReg); } - } if (MustSaveLR) @@ -1109,52 +1170,55 @@ void PPCFrameLowering::emitEpilogue(MachineFunction &MF, // Callee pop calling convention. Pop parameter/linkage area. Used for tail // call optimization - if (MF.getTarget().Options.GuaranteedTailCallOpt && - (RetOpcode == PPC::BLR || RetOpcode == PPC::BLR8) && - MF.getFunction()->getCallingConv() == CallingConv::Fast) { - PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>(); - unsigned CallerAllocatedAmt = FI->getMinReservedArea(); - - if (CallerAllocatedAmt && isInt<16>(CallerAllocatedAmt)) { - BuildMI(MBB, MBBI, dl, AddImmInst, SPReg) - .addReg(SPReg).addImm(CallerAllocatedAmt); - } else { - BuildMI(MBB, MBBI, dl, LoadImmShiftedInst, ScratchReg) + if (IsReturnBlock) { + unsigned RetOpcode = MBBI->getOpcode(); + if (MF.getTarget().Options.GuaranteedTailCallOpt && + (RetOpcode == PPC::BLR || RetOpcode == PPC::BLR8) && + MF.getFunction()->getCallingConv() == CallingConv::Fast) { + PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>(); + unsigned CallerAllocatedAmt = FI->getMinReservedArea(); + + if (CallerAllocatedAmt && isInt<16>(CallerAllocatedAmt)) { + BuildMI(MBB, MBBI, dl, AddImmInst, SPReg) + .addReg(SPReg).addImm(CallerAllocatedAmt); + } else { + BuildMI(MBB, MBBI, dl, LoadImmShiftedInst, ScratchReg) .addImm(CallerAllocatedAmt >> 16); - BuildMI(MBB, MBBI, dl, OrImmInst, ScratchReg) + BuildMI(MBB, MBBI, dl, OrImmInst, ScratchReg) .addReg(ScratchReg, RegState::Kill) .addImm(CallerAllocatedAmt & 0xFFFF); - BuildMI(MBB, MBBI, dl, AddInst) + BuildMI(MBB, MBBI, dl, AddInst) .addReg(SPReg) .addReg(FPReg) .addReg(ScratchReg); - } - } else if (RetOpcode == PPC::TCRETURNdi) { - MBBI = MBB.getLastNonDebugInstr(); - MachineOperand &JumpTarget = MBBI->getOperand(0); - BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILB)). - addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset()); - } else if (RetOpcode == PPC::TCRETURNri) { - MBBI = MBB.getLastNonDebugInstr(); - assert(MBBI->getOperand(0).isReg() && "Expecting register operand."); - BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBCTR)); - } else if (RetOpcode == PPC::TCRETURNai) { - MBBI = MBB.getLastNonDebugInstr(); - MachineOperand &JumpTarget = MBBI->getOperand(0); - BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBA)).addImm(JumpTarget.getImm()); - } else if (RetOpcode == PPC::TCRETURNdi8) { - MBBI = MBB.getLastNonDebugInstr(); - MachineOperand &JumpTarget = MBBI->getOperand(0); - BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILB8)). - addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset()); - } else if (RetOpcode == PPC::TCRETURNri8) { - MBBI = MBB.getLastNonDebugInstr(); - assert(MBBI->getOperand(0).isReg() && "Expecting register operand."); - BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBCTR8)); - } else if (RetOpcode == PPC::TCRETURNai8) { - MBBI = MBB.getLastNonDebugInstr(); - MachineOperand &JumpTarget = MBBI->getOperand(0); - BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBA8)).addImm(JumpTarget.getImm()); + } + } else if (RetOpcode == PPC::TCRETURNdi) { + MBBI = MBB.getLastNonDebugInstr(); + MachineOperand &JumpTarget = MBBI->getOperand(0); + BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILB)). + addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset()); + } else if (RetOpcode == PPC::TCRETURNri) { + MBBI = MBB.getLastNonDebugInstr(); + assert(MBBI->getOperand(0).isReg() && "Expecting register operand."); + BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBCTR)); + } else if (RetOpcode == PPC::TCRETURNai) { + MBBI = MBB.getLastNonDebugInstr(); + MachineOperand &JumpTarget = MBBI->getOperand(0); + BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBA)).addImm(JumpTarget.getImm()); + } else if (RetOpcode == PPC::TCRETURNdi8) { + MBBI = MBB.getLastNonDebugInstr(); + MachineOperand &JumpTarget = MBBI->getOperand(0); + BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILB8)). + addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset()); + } else if (RetOpcode == PPC::TCRETURNri8) { + MBBI = MBB.getLastNonDebugInstr(); + assert(MBBI->getOperand(0).isReg() && "Expecting register operand."); + BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBCTR8)); + } else if (RetOpcode == PPC::TCRETURNai8) { + MBBI = MBB.getLastNonDebugInstr(); + MachineOperand &JumpTarget = MBBI->getOperand(0); + BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBA8)).addImm(JumpTarget.getImm()); + } } } @@ -1200,8 +1264,7 @@ void PPCFrameLowering::determineCalleeSaves(MachineFunction &MF, // Reserve stack space for the PIC Base register (R30). // Only used in SVR4 32-bit. if (FI->usesPICBase()) { - int PBPSI = FI->getPICBasePointerSaveIndex(); - PBPSI = MFI->CreateFixedObject(4, -8, true); + int PBPSI = MFI->CreateFixedObject(4, -8, true); FI->setPICBasePointerSaveIndex(PBPSI); } @@ -1710,3 +1773,8 @@ PPCFrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB, return true; } + +bool PPCFrameLowering::enableShrinkWrapping(const MachineFunction &MF) const { + return (MF.getSubtarget<PPCSubtarget>().isSVR4ABI() && + MF.getSubtarget<PPCSubtarget>().isPPC64()); +} |
