forked from OSchip/llvm-project
1427 lines
52 KiB
C++
1427 lines
52 KiB
C++
//===-- PPCFrameLowering.cpp - PPC Frame Information ----------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file contains the PPC implementation of TargetFrameLowering class.
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//
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//===----------------------------------------------------------------------===//
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#include "PPCFrameLowering.h"
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#include "PPCInstrBuilder.h"
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#include "PPCInstrInfo.h"
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#include "PPCMachineFunctionInfo.h"
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#include "llvm/CodeGen/MachineFrameInfo.h"
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#include "llvm/CodeGen/MachineFunction.h"
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#include "llvm/CodeGen/MachineInstrBuilder.h"
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#include "llvm/CodeGen/MachineModuleInfo.h"
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#include "llvm/CodeGen/MachineRegisterInfo.h"
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#include "llvm/CodeGen/RegisterScavenging.h"
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#include "llvm/IR/Function.h"
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#include "llvm/Target/TargetOptions.h"
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using namespace llvm;
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/// VRRegNo - Map from a numbered VR register to its enum value.
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///
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static const uint16_t VRRegNo[] = {
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PPC::V0 , PPC::V1 , PPC::V2 , PPC::V3 , PPC::V4 , PPC::V5 , PPC::V6 , PPC::V7 ,
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PPC::V8 , PPC::V9 , PPC::V10, PPC::V11, PPC::V12, PPC::V13, PPC::V14, PPC::V15,
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PPC::V16, PPC::V17, PPC::V18, PPC::V19, PPC::V20, PPC::V21, PPC::V22, PPC::V23,
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PPC::V24, PPC::V25, PPC::V26, PPC::V27, PPC::V28, PPC::V29, PPC::V30, PPC::V31
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};
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/// RemoveVRSaveCode - We have found that this function does not need any code
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/// to manipulate the VRSAVE register, even though it uses vector registers.
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/// This can happen when the only registers used are known to be live in or out
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/// of the function. Remove all of the VRSAVE related code from the function.
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/// FIXME: The removal of the code results in a compile failure at -O0 when the
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/// function contains a function call, as the GPR containing original VRSAVE
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/// contents is spilled and reloaded around the call. Without the prolog code,
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/// the spill instruction refers to an undefined register. This code needs
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/// to account for all uses of that GPR.
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static void RemoveVRSaveCode(MachineInstr *MI) {
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MachineBasicBlock *Entry = MI->getParent();
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MachineFunction *MF = Entry->getParent();
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// We know that the MTVRSAVE instruction immediately follows MI. Remove it.
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MachineBasicBlock::iterator MBBI = MI;
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++MBBI;
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assert(MBBI != Entry->end() && MBBI->getOpcode() == PPC::MTVRSAVE);
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MBBI->eraseFromParent();
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bool RemovedAllMTVRSAVEs = true;
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// See if we can find and remove the MTVRSAVE instruction from all of the
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// epilog blocks.
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for (MachineFunction::iterator I = MF->begin(), E = MF->end(); I != E; ++I) {
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// If last instruction is a return instruction, add an epilogue
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if (!I->empty() && I->back().isReturn()) {
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bool FoundIt = false;
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for (MBBI = I->end(); MBBI != I->begin(); ) {
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--MBBI;
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if (MBBI->getOpcode() == PPC::MTVRSAVE) {
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MBBI->eraseFromParent(); // remove it.
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FoundIt = true;
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break;
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}
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}
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RemovedAllMTVRSAVEs &= FoundIt;
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}
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}
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// If we found and removed all MTVRSAVE instructions, remove the read of
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// VRSAVE as well.
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if (RemovedAllMTVRSAVEs) {
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MBBI = MI;
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assert(MBBI != Entry->begin() && "UPDATE_VRSAVE is first instr in block?");
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--MBBI;
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assert(MBBI->getOpcode() == PPC::MFVRSAVE && "VRSAVE instrs wandered?");
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MBBI->eraseFromParent();
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}
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// Finally, nuke the UPDATE_VRSAVE.
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MI->eraseFromParent();
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}
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// HandleVRSaveUpdate - MI is the UPDATE_VRSAVE instruction introduced by the
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// instruction selector. Based on the vector registers that have been used,
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// transform this into the appropriate ORI instruction.
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static void HandleVRSaveUpdate(MachineInstr *MI, const TargetInstrInfo &TII) {
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MachineFunction *MF = MI->getParent()->getParent();
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const TargetRegisterInfo *TRI = MF->getTarget().getRegisterInfo();
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DebugLoc dl = MI->getDebugLoc();
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unsigned UsedRegMask = 0;
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for (unsigned i = 0; i != 32; ++i)
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if (MF->getRegInfo().isPhysRegUsed(VRRegNo[i]))
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UsedRegMask |= 1 << (31-i);
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// Live in and live out values already must be in the mask, so don't bother
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// marking them.
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for (MachineRegisterInfo::livein_iterator
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I = MF->getRegInfo().livein_begin(),
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E = MF->getRegInfo().livein_end(); I != E; ++I) {
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unsigned RegNo = TRI->getEncodingValue(I->first);
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if (VRRegNo[RegNo] == I->first) // If this really is a vector reg.
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UsedRegMask &= ~(1 << (31-RegNo)); // Doesn't need to be marked.
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}
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// Live out registers appear as use operands on return instructions.
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for (MachineFunction::const_iterator BI = MF->begin(), BE = MF->end();
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UsedRegMask != 0 && BI != BE; ++BI) {
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const MachineBasicBlock &MBB = *BI;
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if (MBB.empty() || !MBB.back().isReturn())
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continue;
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const MachineInstr &Ret = MBB.back();
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for (unsigned I = 0, E = Ret.getNumOperands(); I != E; ++I) {
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const MachineOperand &MO = Ret.getOperand(I);
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if (!MO.isReg() || !PPC::VRRCRegClass.contains(MO.getReg()))
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continue;
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unsigned RegNo = TRI->getEncodingValue(MO.getReg());
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UsedRegMask &= ~(1 << (31-RegNo));
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}
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}
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// If no registers are used, turn this into a copy.
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if (UsedRegMask == 0) {
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// Remove all VRSAVE code.
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RemoveVRSaveCode(MI);
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return;
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}
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unsigned SrcReg = MI->getOperand(1).getReg();
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unsigned DstReg = MI->getOperand(0).getReg();
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if ((UsedRegMask & 0xFFFF) == UsedRegMask) {
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if (DstReg != SrcReg)
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BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORI), DstReg)
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.addReg(SrcReg)
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.addImm(UsedRegMask);
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else
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BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORI), DstReg)
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.addReg(SrcReg, RegState::Kill)
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.addImm(UsedRegMask);
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} else if ((UsedRegMask & 0xFFFF0000) == UsedRegMask) {
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if (DstReg != SrcReg)
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BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORIS), DstReg)
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.addReg(SrcReg)
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.addImm(UsedRegMask >> 16);
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else
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BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORIS), DstReg)
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.addReg(SrcReg, RegState::Kill)
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.addImm(UsedRegMask >> 16);
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} else {
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if (DstReg != SrcReg)
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BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORIS), DstReg)
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.addReg(SrcReg)
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.addImm(UsedRegMask >> 16);
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else
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BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORIS), DstReg)
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.addReg(SrcReg, RegState::Kill)
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.addImm(UsedRegMask >> 16);
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BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORI), DstReg)
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.addReg(DstReg, RegState::Kill)
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.addImm(UsedRegMask & 0xFFFF);
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}
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// Remove the old UPDATE_VRSAVE instruction.
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MI->eraseFromParent();
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}
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static bool spillsCR(const MachineFunction &MF) {
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const PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
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return FuncInfo->isCRSpilled();
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}
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static bool spillsVRSAVE(const MachineFunction &MF) {
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const PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
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return FuncInfo->isVRSAVESpilled();
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}
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static bool hasSpills(const MachineFunction &MF) {
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const PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
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return FuncInfo->hasSpills();
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}
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static bool hasNonRISpills(const MachineFunction &MF) {
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const PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
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return FuncInfo->hasNonRISpills();
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}
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/// determineFrameLayout - Determine the size of the frame and maximum call
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/// frame size.
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unsigned PPCFrameLowering::determineFrameLayout(MachineFunction &MF,
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bool UpdateMF,
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bool UseEstimate) const {
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MachineFrameInfo *MFI = MF.getFrameInfo();
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// Get the number of bytes to allocate from the FrameInfo
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unsigned FrameSize =
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UseEstimate ? MFI->estimateStackSize(MF) : MFI->getStackSize();
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// Get stack alignments. The frame must be aligned to the greatest of these:
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unsigned TargetAlign = getStackAlignment(); // alignment required per the ABI
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unsigned MaxAlign = MFI->getMaxAlignment(); // algmt required by data in frame
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unsigned AlignMask = std::max(MaxAlign, TargetAlign) - 1;
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const PPCRegisterInfo *RegInfo =
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static_cast<const PPCRegisterInfo*>(MF.getTarget().getRegisterInfo());
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// If we are a leaf function, and use up to 224 bytes of stack space,
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// don't have a frame pointer, calls, or dynamic alloca then we do not need
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// to adjust the stack pointer (we fit in the Red Zone).
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// The 32-bit SVR4 ABI has no Red Zone. However, it can still generate
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// stackless code if all local vars are reg-allocated.
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bool DisableRedZone = MF.getFunction()->getAttributes().
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hasAttribute(AttributeSet::FunctionIndex, Attribute::NoRedZone);
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if (!DisableRedZone &&
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(Subtarget.isPPC64() || // 32-bit SVR4, no stack-
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!Subtarget.isSVR4ABI() || // allocated locals.
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FrameSize == 0) &&
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FrameSize <= 224 && // Fits in red zone.
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!MFI->hasVarSizedObjects() && // No dynamic alloca.
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!MFI->adjustsStack() && // No calls.
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!RegInfo->hasBasePointer(MF)) { // No special alignment.
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// No need for frame
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if (UpdateMF)
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MFI->setStackSize(0);
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return 0;
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}
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// Get the maximum call frame size of all the calls.
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unsigned maxCallFrameSize = MFI->getMaxCallFrameSize();
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// Maximum call frame needs to be at least big enough for linkage and 8 args.
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unsigned minCallFrameSize = getMinCallFrameSize(Subtarget.isPPC64(),
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Subtarget.isDarwinABI());
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maxCallFrameSize = std::max(maxCallFrameSize, minCallFrameSize);
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// If we have dynamic alloca then maxCallFrameSize needs to be aligned so
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// that allocations will be aligned.
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if (MFI->hasVarSizedObjects())
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maxCallFrameSize = (maxCallFrameSize + AlignMask) & ~AlignMask;
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// Update maximum call frame size.
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if (UpdateMF)
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MFI->setMaxCallFrameSize(maxCallFrameSize);
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// Include call frame size in total.
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FrameSize += maxCallFrameSize;
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// Make sure the frame is aligned.
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FrameSize = (FrameSize + AlignMask) & ~AlignMask;
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// Update frame info.
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if (UpdateMF)
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MFI->setStackSize(FrameSize);
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return FrameSize;
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}
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// hasFP - Return true if the specified function actually has a dedicated frame
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// pointer register.
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bool PPCFrameLowering::hasFP(const MachineFunction &MF) const {
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const MachineFrameInfo *MFI = MF.getFrameInfo();
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// FIXME: This is pretty much broken by design: hasFP() might be called really
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// early, before the stack layout was calculated and thus hasFP() might return
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// true or false here depending on the time of call.
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return (MFI->getStackSize()) && needsFP(MF);
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}
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// needsFP - Return true if the specified function should have a dedicated frame
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// pointer register. This is true if the function has variable sized allocas or
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// if frame pointer elimination is disabled.
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bool PPCFrameLowering::needsFP(const MachineFunction &MF) const {
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const MachineFrameInfo *MFI = MF.getFrameInfo();
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// Naked functions have no stack frame pushed, so we don't have a frame
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// pointer.
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if (MF.getFunction()->getAttributes().hasAttribute(
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AttributeSet::FunctionIndex, Attribute::Naked))
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return false;
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return MF.getTarget().Options.DisableFramePointerElim(MF) ||
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MFI->hasVarSizedObjects() ||
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(MF.getTarget().Options.GuaranteedTailCallOpt &&
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MF.getInfo<PPCFunctionInfo>()->hasFastCall());
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}
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void PPCFrameLowering::replaceFPWithRealFP(MachineFunction &MF) const {
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bool is31 = needsFP(MF);
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unsigned FPReg = is31 ? PPC::R31 : PPC::R1;
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unsigned FP8Reg = is31 ? PPC::X31 : PPC::X1;
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const PPCRegisterInfo *RegInfo =
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static_cast<const PPCRegisterInfo*>(MF.getTarget().getRegisterInfo());
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bool HasBP = RegInfo->hasBasePointer(MF);
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unsigned BPReg = HasBP ? (unsigned) PPC::R30 : FPReg;
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unsigned BP8Reg = HasBP ? (unsigned) PPC::X30 : FPReg;
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for (MachineFunction::iterator BI = MF.begin(), BE = MF.end();
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BI != BE; ++BI)
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for (MachineBasicBlock::iterator MBBI = BI->end(); MBBI != BI->begin(); ) {
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--MBBI;
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for (unsigned I = 0, E = MBBI->getNumOperands(); I != E; ++I) {
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MachineOperand &MO = MBBI->getOperand(I);
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if (!MO.isReg())
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continue;
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switch (MO.getReg()) {
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case PPC::FP:
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MO.setReg(FPReg);
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break;
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case PPC::FP8:
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MO.setReg(FP8Reg);
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break;
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case PPC::BP:
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MO.setReg(BPReg);
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break;
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case PPC::BP8:
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MO.setReg(BP8Reg);
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break;
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}
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}
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}
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}
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void PPCFrameLowering::emitPrologue(MachineFunction &MF) const {
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MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
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MachineBasicBlock::iterator MBBI = MBB.begin();
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MachineFrameInfo *MFI = MF.getFrameInfo();
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const PPCInstrInfo &TII =
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*static_cast<const PPCInstrInfo*>(MF.getTarget().getInstrInfo());
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const PPCRegisterInfo *RegInfo =
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static_cast<const PPCRegisterInfo*>(MF.getTarget().getRegisterInfo());
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MachineModuleInfo &MMI = MF.getMMI();
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const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
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DebugLoc dl;
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bool needsFrameMoves = MMI.hasDebugInfo() ||
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MF.getFunction()->needsUnwindTableEntry();
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// Get processor type.
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bool isPPC64 = Subtarget.isPPC64();
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// Get the ABI.
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bool isDarwinABI = Subtarget.isDarwinABI();
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bool isSVR4ABI = Subtarget.isSVR4ABI();
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assert((isDarwinABI || isSVR4ABI) &&
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"Currently only Darwin and SVR4 ABIs are supported for PowerPC.");
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// Scan the prolog, looking for an UPDATE_VRSAVE instruction. If we find it,
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// process it.
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if (!isSVR4ABI)
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for (unsigned i = 0; MBBI != MBB.end(); ++i, ++MBBI) {
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if (MBBI->getOpcode() == PPC::UPDATE_VRSAVE) {
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HandleVRSaveUpdate(MBBI, TII);
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break;
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}
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}
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// Move MBBI back to the beginning of the function.
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MBBI = MBB.begin();
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// Work out frame sizes.
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unsigned FrameSize = determineFrameLayout(MF);
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int NegFrameSize = -FrameSize;
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if (!isInt<32>(NegFrameSize))
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llvm_unreachable("Unhandled stack size!");
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if (MFI->isFrameAddressTaken())
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replaceFPWithRealFP(MF);
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// Check if the link register (LR) must be saved.
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PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
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bool MustSaveLR = FI->mustSaveLR();
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const SmallVectorImpl<unsigned> &MustSaveCRs = FI->getMustSaveCRs();
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// Do we have a frame pointer and/or base pointer for this function?
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bool HasFP = hasFP(MF);
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bool HasBP = RegInfo->hasBasePointer(MF);
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unsigned SPReg = isPPC64 ? PPC::X1 : PPC::R1;
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unsigned BPReg = isPPC64 ? PPC::X30 : PPC::R30;
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unsigned FPReg = isPPC64 ? PPC::X31 : PPC::R31;
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unsigned LRReg = isPPC64 ? PPC::LR8 : PPC::LR;
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unsigned ScratchReg = isPPC64 ? PPC::X0 : PPC::R0;
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unsigned TempReg = isPPC64 ? PPC::X12 : PPC::R12; // another scratch reg
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// ...(R12/X12 is volatile in both Darwin & SVR4, & can't be a function arg.)
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const MCInstrDesc& MFLRInst = TII.get(isPPC64 ? PPC::MFLR8
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: PPC::MFLR );
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const MCInstrDesc& StoreInst = TII.get(isPPC64 ? PPC::STD
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: PPC::STW );
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const MCInstrDesc& StoreUpdtInst = TII.get(isPPC64 ? PPC::STDU
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: PPC::STWU );
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const MCInstrDesc& StoreUpdtIdxInst = TII.get(isPPC64 ? PPC::STDUX
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: PPC::STWUX);
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const MCInstrDesc& LoadImmShiftedInst = TII.get(isPPC64 ? PPC::LIS8
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: PPC::LIS );
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const MCInstrDesc& OrImmInst = TII.get(isPPC64 ? PPC::ORI8
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: PPC::ORI );
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const MCInstrDesc& OrInst = TII.get(isPPC64 ? PPC::OR8
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: PPC::OR );
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const MCInstrDesc& SubtractCarryingInst = TII.get(isPPC64 ? PPC::SUBFC8
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: PPC::SUBFC);
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const MCInstrDesc& SubtractImmCarryingInst = TII.get(isPPC64 ? PPC::SUBFIC8
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: PPC::SUBFIC);
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// Regarding this assert: Even though LR is saved in the caller's frame (i.e.,
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// LROffset is positive), that slot is callee-owned. Because PPC32 SVR4 has no
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// Red Zone, an asynchronous event (a form of "callee") could claim a frame &
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// overwrite it, so PPC32 SVR4 must claim at least a minimal frame to save LR.
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assert((isPPC64 || !isSVR4ABI || !(!FrameSize && (MustSaveLR || HasFP))) &&
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"FrameSize must be >0 to save/restore the FP or LR for 32-bit SVR4.");
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int LROffset = PPCFrameLowering::getReturnSaveOffset(isPPC64, isDarwinABI);
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int FPOffset = 0;
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if (HasFP) {
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if (isSVR4ABI) {
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MachineFrameInfo *FFI = MF.getFrameInfo();
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int FPIndex = FI->getFramePointerSaveIndex();
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assert(FPIndex && "No Frame Pointer Save Slot!");
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FPOffset = FFI->getObjectOffset(FPIndex);
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} else {
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FPOffset =
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PPCFrameLowering::getFramePointerSaveOffset(isPPC64, isDarwinABI);
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}
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}
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int BPOffset = 0;
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if (HasBP) {
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if (isSVR4ABI) {
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MachineFrameInfo *FFI = MF.getFrameInfo();
|
|
int BPIndex = FI->getBasePointerSaveIndex();
|
|
assert(BPIndex && "No Base Pointer Save Slot!");
|
|
BPOffset = FFI->getObjectOffset(BPIndex);
|
|
} else {
|
|
BPOffset =
|
|
PPCFrameLowering::getBasePointerSaveOffset(isPPC64, isDarwinABI);
|
|
}
|
|
}
|
|
|
|
// Get stack alignments.
|
|
unsigned MaxAlign = MFI->getMaxAlignment();
|
|
if (HasBP && MaxAlign > 1)
|
|
assert(isPowerOf2_32(MaxAlign) && isInt<16>(MaxAlign) &&
|
|
"Invalid alignment!");
|
|
|
|
// Frames of 32KB & larger require special handling because they cannot be
|
|
// indexed into with a simple STDU/STWU/STD/STW immediate offset operand.
|
|
bool isLargeFrame = !isInt<16>(NegFrameSize);
|
|
|
|
if (MustSaveLR)
|
|
BuildMI(MBB, MBBI, dl, MFLRInst, ScratchReg);
|
|
|
|
assert((isPPC64 || MustSaveCRs.empty()) &&
|
|
"Prologue CR saving supported only in 64-bit mode");
|
|
|
|
if (!MustSaveCRs.empty()) { // will only occur for PPC64
|
|
MachineInstrBuilder MIB =
|
|
BuildMI(MBB, MBBI, dl, TII.get(PPC::MFCR8), TempReg);
|
|
for (unsigned i = 0, e = MustSaveCRs.size(); i != e; ++i)
|
|
MIB.addReg(MustSaveCRs[i], RegState::ImplicitKill);
|
|
}
|
|
|
|
if (HasFP)
|
|
// FIXME: On PPC32 SVR4, we must not spill before claiming the stackframe.
|
|
BuildMI(MBB, MBBI, dl, StoreInst)
|
|
.addReg(FPReg)
|
|
.addImm(FPOffset)
|
|
.addReg(SPReg);
|
|
|
|
if (HasBP)
|
|
// FIXME: On PPC32 SVR4, we must not spill before claiming the stackframe.
|
|
BuildMI(MBB, MBBI, dl, StoreInst)
|
|
.addReg(BPReg)
|
|
.addImm(BPOffset)
|
|
.addReg(SPReg);
|
|
|
|
if (MustSaveLR)
|
|
// FIXME: On PPC32 SVR4, we must not spill before claiming the stackframe.
|
|
BuildMI(MBB, MBBI, dl, StoreInst)
|
|
.addReg(ScratchReg)
|
|
.addImm(LROffset)
|
|
.addReg(SPReg);
|
|
|
|
if (!MustSaveCRs.empty()) // will only occur for PPC64
|
|
BuildMI(MBB, MBBI, dl, TII.get(PPC::STW8))
|
|
.addReg(TempReg, getKillRegState(true))
|
|
.addImm(8)
|
|
.addReg(SPReg);
|
|
|
|
// Skip the rest if this is a leaf function & all spills fit in the Red Zone.
|
|
if (!FrameSize) return;
|
|
|
|
// Adjust stack pointer: r1 += NegFrameSize.
|
|
// If there is a preferred stack alignment, align R1 now
|
|
|
|
if (HasBP) {
|
|
// Save a copy of r1 as the base pointer.
|
|
BuildMI(MBB, MBBI, dl, OrInst, BPReg)
|
|
.addReg(SPReg)
|
|
.addReg(SPReg);
|
|
}
|
|
|
|
if (HasBP && MaxAlign > 1) {
|
|
if (isPPC64)
|
|
BuildMI(MBB, MBBI, dl, TII.get(PPC::RLDICL), ScratchReg)
|
|
.addReg(SPReg)
|
|
.addImm(0)
|
|
.addImm(64 - Log2_32(MaxAlign));
|
|
else // PPC32...
|
|
BuildMI(MBB, MBBI, dl, TII.get(PPC::RLWINM), ScratchReg)
|
|
.addReg(SPReg)
|
|
.addImm(0)
|
|
.addImm(32 - Log2_32(MaxAlign))
|
|
.addImm(31);
|
|
if (!isLargeFrame) {
|
|
BuildMI(MBB, MBBI, dl, SubtractImmCarryingInst, ScratchReg)
|
|
.addReg(ScratchReg, RegState::Kill)
|
|
.addImm(NegFrameSize);
|
|
} else {
|
|
BuildMI(MBB, MBBI, dl, LoadImmShiftedInst, TempReg)
|
|
.addImm(NegFrameSize >> 16);
|
|
BuildMI(MBB, MBBI, dl, OrImmInst, TempReg)
|
|
.addReg(TempReg, RegState::Kill)
|
|
.addImm(NegFrameSize & 0xFFFF);
|
|
BuildMI(MBB, MBBI, dl, SubtractCarryingInst, ScratchReg)
|
|
.addReg(ScratchReg, RegState::Kill)
|
|
.addReg(TempReg, RegState::Kill);
|
|
}
|
|
BuildMI(MBB, MBBI, dl, StoreUpdtIdxInst, SPReg)
|
|
.addReg(SPReg, RegState::Kill)
|
|
.addReg(SPReg)
|
|
.addReg(ScratchReg);
|
|
|
|
} else if (!isLargeFrame) {
|
|
BuildMI(MBB, MBBI, dl, StoreUpdtInst, SPReg)
|
|
.addReg(SPReg)
|
|
.addImm(NegFrameSize)
|
|
.addReg(SPReg);
|
|
|
|
} else {
|
|
BuildMI(MBB, MBBI, dl, LoadImmShiftedInst, ScratchReg)
|
|
.addImm(NegFrameSize >> 16);
|
|
BuildMI(MBB, MBBI, dl, OrImmInst, ScratchReg)
|
|
.addReg(ScratchReg, RegState::Kill)
|
|
.addImm(NegFrameSize & 0xFFFF);
|
|
BuildMI(MBB, MBBI, dl, StoreUpdtIdxInst, SPReg)
|
|
.addReg(SPReg, RegState::Kill)
|
|
.addReg(SPReg)
|
|
.addReg(ScratchReg);
|
|
}
|
|
|
|
// Add the "machine moves" for the instructions we generated above, but in
|
|
// reverse order.
|
|
if (needsFrameMoves) {
|
|
// Show update of SP.
|
|
assert(NegFrameSize);
|
|
unsigned CFIIndex = MMI.addFrameInst(
|
|
MCCFIInstruction::createDefCfaOffset(nullptr, NegFrameSize));
|
|
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
|
|
.addCFIIndex(CFIIndex);
|
|
|
|
if (HasFP) {
|
|
unsigned Reg = MRI->getDwarfRegNum(FPReg, true);
|
|
CFIIndex = MMI.addFrameInst(
|
|
MCCFIInstruction::createOffset(nullptr, Reg, FPOffset));
|
|
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
|
|
.addCFIIndex(CFIIndex);
|
|
}
|
|
|
|
if (HasBP) {
|
|
unsigned Reg = MRI->getDwarfRegNum(BPReg, true);
|
|
CFIIndex = MMI.addFrameInst(
|
|
MCCFIInstruction::createOffset(nullptr, Reg, BPOffset));
|
|
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
|
|
.addCFIIndex(CFIIndex);
|
|
}
|
|
|
|
if (MustSaveLR) {
|
|
unsigned Reg = MRI->getDwarfRegNum(LRReg, true);
|
|
CFIIndex = MMI.addFrameInst(
|
|
MCCFIInstruction::createOffset(nullptr, Reg, LROffset));
|
|
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
|
|
.addCFIIndex(CFIIndex);
|
|
}
|
|
}
|
|
|
|
// If there is a frame pointer, copy R1 into R31
|
|
if (HasFP) {
|
|
BuildMI(MBB, MBBI, dl, OrInst, FPReg)
|
|
.addReg(SPReg)
|
|
.addReg(SPReg);
|
|
|
|
if (needsFrameMoves) {
|
|
// Mark effective beginning of when frame pointer is ready.
|
|
unsigned Reg = MRI->getDwarfRegNum(FPReg, true);
|
|
unsigned CFIIndex = MMI.addFrameInst(
|
|
MCCFIInstruction::createDefCfaRegister(nullptr, Reg));
|
|
|
|
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
|
|
.addCFIIndex(CFIIndex);
|
|
}
|
|
}
|
|
|
|
if (needsFrameMoves) {
|
|
// Add callee saved registers to move list.
|
|
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
|
|
for (unsigned I = 0, E = CSI.size(); I != E; ++I) {
|
|
unsigned Reg = CSI[I].getReg();
|
|
if (Reg == PPC::LR || Reg == PPC::LR8 || Reg == PPC::RM) continue;
|
|
|
|
// This is a bit of a hack: CR2LT, CR2GT, CR2EQ and CR2UN are just
|
|
// subregisters of CR2. We just need to emit a move of CR2.
|
|
if (PPC::CRBITRCRegClass.contains(Reg))
|
|
continue;
|
|
|
|
// For SVR4, don't emit a move for the CR spill slot if we haven't
|
|
// spilled CRs.
|
|
if (isSVR4ABI && (PPC::CR2 <= Reg && Reg <= PPC::CR4)
|
|
&& MustSaveCRs.empty())
|
|
continue;
|
|
|
|
// For 64-bit SVR4 when we have spilled CRs, the spill location
|
|
// is SP+8, not a frame-relative slot.
|
|
if (isSVR4ABI && isPPC64 && (PPC::CR2 <= Reg && Reg <= PPC::CR4)) {
|
|
unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createOffset(
|
|
nullptr, MRI->getDwarfRegNum(PPC::CR2, true), 8));
|
|
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
|
|
.addCFIIndex(CFIIndex);
|
|
continue;
|
|
}
|
|
|
|
int Offset = MFI->getObjectOffset(CSI[I].getFrameIdx());
|
|
unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createOffset(
|
|
nullptr, MRI->getDwarfRegNum(Reg, true), Offset));
|
|
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
|
|
.addCFIIndex(CFIIndex);
|
|
}
|
|
}
|
|
}
|
|
|
|
void PPCFrameLowering::emitEpilogue(MachineFunction &MF,
|
|
MachineBasicBlock &MBB) const {
|
|
MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
|
|
assert(MBBI != MBB.end() && "Returning block has no terminator");
|
|
const PPCInstrInfo &TII =
|
|
*static_cast<const PPCInstrInfo*>(MF.getTarget().getInstrInfo());
|
|
const PPCRegisterInfo *RegInfo =
|
|
static_cast<const PPCRegisterInfo*>(MF.getTarget().getRegisterInfo());
|
|
|
|
unsigned RetOpcode = MBBI->getOpcode();
|
|
DebugLoc dl;
|
|
|
|
assert((RetOpcode == PPC::BLR ||
|
|
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();
|
|
|
|
// Get the number of bytes allocated from the FrameInfo.
|
|
int FrameSize = MFI->getStackSize();
|
|
|
|
// Get processor type.
|
|
bool isPPC64 = Subtarget.isPPC64();
|
|
// Get the ABI.
|
|
bool isDarwinABI = Subtarget.isDarwinABI();
|
|
bool isSVR4ABI = Subtarget.isSVR4ABI();
|
|
|
|
// Check if the link register (LR) has been saved.
|
|
PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
|
|
bool MustSaveLR = FI->mustSaveLR();
|
|
const SmallVectorImpl<unsigned> &MustSaveCRs = FI->getMustSaveCRs();
|
|
// Do we have a frame pointer and/or base pointer for this function?
|
|
bool HasFP = hasFP(MF);
|
|
bool HasBP = RegInfo->hasBasePointer(MF);
|
|
|
|
unsigned SPReg = isPPC64 ? PPC::X1 : PPC::R1;
|
|
unsigned BPReg = isPPC64 ? PPC::X30 : PPC::R30;
|
|
unsigned FPReg = isPPC64 ? PPC::X31 : PPC::R31;
|
|
unsigned ScratchReg = isPPC64 ? PPC::X0 : PPC::R0;
|
|
unsigned TempReg = isPPC64 ? PPC::X12 : PPC::R12; // another scratch reg
|
|
const MCInstrDesc& MTLRInst = TII.get( isPPC64 ? PPC::MTLR8
|
|
: PPC::MTLR );
|
|
const MCInstrDesc& LoadInst = TII.get( isPPC64 ? PPC::LD
|
|
: PPC::LWZ );
|
|
const MCInstrDesc& LoadImmShiftedInst = TII.get( isPPC64 ? PPC::LIS8
|
|
: PPC::LIS );
|
|
const MCInstrDesc& OrImmInst = TII.get( isPPC64 ? PPC::ORI8
|
|
: PPC::ORI );
|
|
const MCInstrDesc& AddImmInst = TII.get( isPPC64 ? PPC::ADDI8
|
|
: PPC::ADDI );
|
|
const MCInstrDesc& AddInst = TII.get( isPPC64 ? PPC::ADD8
|
|
: PPC::ADD4 );
|
|
|
|
int LROffset = PPCFrameLowering::getReturnSaveOffset(isPPC64, isDarwinABI);
|
|
|
|
int FPOffset = 0;
|
|
if (HasFP) {
|
|
if (isSVR4ABI) {
|
|
MachineFrameInfo *FFI = MF.getFrameInfo();
|
|
int FPIndex = FI->getFramePointerSaveIndex();
|
|
assert(FPIndex && "No Frame Pointer Save Slot!");
|
|
FPOffset = FFI->getObjectOffset(FPIndex);
|
|
} else {
|
|
FPOffset =
|
|
PPCFrameLowering::getFramePointerSaveOffset(isPPC64, isDarwinABI);
|
|
}
|
|
}
|
|
|
|
int BPOffset = 0;
|
|
if (HasBP) {
|
|
if (isSVR4ABI) {
|
|
MachineFrameInfo *FFI = MF.getFrameInfo();
|
|
int BPIndex = FI->getBasePointerSaveIndex();
|
|
assert(BPIndex && "No Base Pointer Save Slot!");
|
|
BPOffset = FFI->getObjectOffset(BPIndex);
|
|
} else {
|
|
BPOffset =
|
|
PPCFrameLowering::getBasePointerSaveOffset(isPPC64, isDarwinABI);
|
|
}
|
|
}
|
|
|
|
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
|
|
// indexed into with a simple LD/LWZ immediate offset operand.
|
|
bool isLargeFrame = !isInt<16>(FrameSize);
|
|
|
|
if (FrameSize) {
|
|
// In the prologue, the loaded (or persistent) stack pointer value is offset
|
|
// by the STDU/STDUX/STWU/STWUX instruction. Add this offset back now.
|
|
|
|
// If this function contained a fastcc call and GuaranteedTailCallOpt is
|
|
// enabled (=> hasFastCall()==true) the fastcc call might contain a tail
|
|
// call which invalidates the stack pointer value in SP(0). So we use the
|
|
// value of R31 in this case.
|
|
if (FI->hasFastCall()) {
|
|
assert(HasFP && "Expecting a valid frame pointer.");
|
|
if (!isLargeFrame) {
|
|
BuildMI(MBB, MBBI, dl, AddImmInst, SPReg)
|
|
.addReg(FPReg).addImm(FrameSize);
|
|
} else {
|
|
BuildMI(MBB, MBBI, dl, LoadImmShiftedInst, ScratchReg)
|
|
.addImm(FrameSize >> 16);
|
|
BuildMI(MBB, MBBI, dl, OrImmInst, ScratchReg)
|
|
.addReg(ScratchReg, RegState::Kill)
|
|
.addImm(FrameSize & 0xFFFF);
|
|
BuildMI(MBB, MBBI, dl, AddInst)
|
|
.addReg(SPReg)
|
|
.addReg(FPReg)
|
|
.addReg(ScratchReg);
|
|
}
|
|
} else if (!isLargeFrame && !HasBP && !MFI->hasVarSizedObjects()) {
|
|
BuildMI(MBB, MBBI, dl, AddImmInst, SPReg)
|
|
.addReg(SPReg)
|
|
.addImm(FrameSize);
|
|
} else {
|
|
BuildMI(MBB, MBBI, dl, LoadInst, SPReg)
|
|
.addImm(0)
|
|
.addReg(SPReg);
|
|
}
|
|
|
|
}
|
|
|
|
if (MustSaveLR)
|
|
BuildMI(MBB, MBBI, dl, LoadInst, ScratchReg)
|
|
.addImm(LROffset)
|
|
.addReg(SPReg);
|
|
|
|
assert((isPPC64 || MustSaveCRs.empty()) &&
|
|
"Epilogue CR restoring supported only in 64-bit mode");
|
|
|
|
if (!MustSaveCRs.empty()) // will only occur for PPC64
|
|
BuildMI(MBB, MBBI, dl, TII.get(PPC::LWZ8), TempReg)
|
|
.addImm(8)
|
|
.addReg(SPReg);
|
|
|
|
if (HasFP)
|
|
BuildMI(MBB, MBBI, dl, LoadInst, FPReg)
|
|
.addImm(FPOffset)
|
|
.addReg(SPReg);
|
|
|
|
if (HasBP)
|
|
BuildMI(MBB, MBBI, dl, LoadInst, BPReg)
|
|
.addImm(BPOffset)
|
|
.addReg(SPReg);
|
|
|
|
if (!MustSaveCRs.empty()) // will only occur for PPC64
|
|
for (unsigned i = 0, e = MustSaveCRs.size(); i != e; ++i)
|
|
BuildMI(MBB, MBBI, dl, TII.get(PPC::MTOCRF8), MustSaveCRs[i])
|
|
.addReg(TempReg, getKillRegState(i == e-1));
|
|
|
|
if (MustSaveLR)
|
|
BuildMI(MBB, MBBI, dl, MTLRInst).addReg(ScratchReg);
|
|
|
|
// Callee pop calling convention. Pop parameter/linkage area. Used for tail
|
|
// call optimization
|
|
if (MF.getTarget().Options.GuaranteedTailCallOpt && RetOpcode == PPC::BLR &&
|
|
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)
|
|
.addReg(ScratchReg, RegState::Kill)
|
|
.addImm(CallerAllocatedAmt & 0xFFFF);
|
|
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());
|
|
}
|
|
}
|
|
|
|
/// MustSaveLR - Return true if this function requires that we save the LR
|
|
/// register onto the stack in the prolog and restore it in the epilog of the
|
|
/// function.
|
|
static bool MustSaveLR(const MachineFunction &MF, unsigned LR) {
|
|
const PPCFunctionInfo *MFI = MF.getInfo<PPCFunctionInfo>();
|
|
|
|
// We need a save/restore of LR if there is any def of LR (which is
|
|
// defined by calls, including the PIC setup sequence), or if there is
|
|
// some use of the LR stack slot (e.g. for builtin_return_address).
|
|
// (LR comes in 32 and 64 bit versions.)
|
|
MachineRegisterInfo::def_iterator RI = MF.getRegInfo().def_begin(LR);
|
|
return RI !=MF.getRegInfo().def_end() || MFI->isLRStoreRequired();
|
|
}
|
|
|
|
void
|
|
PPCFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
|
|
RegScavenger *) const {
|
|
const PPCRegisterInfo *RegInfo =
|
|
static_cast<const PPCRegisterInfo*>(MF.getTarget().getRegisterInfo());
|
|
|
|
// Save and clear the LR state.
|
|
PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
|
|
unsigned LR = RegInfo->getRARegister();
|
|
FI->setMustSaveLR(MustSaveLR(MF, LR));
|
|
MachineRegisterInfo &MRI = MF.getRegInfo();
|
|
MRI.setPhysRegUnused(LR);
|
|
|
|
// Save R31 if necessary
|
|
int FPSI = FI->getFramePointerSaveIndex();
|
|
bool isPPC64 = Subtarget.isPPC64();
|
|
bool isDarwinABI = Subtarget.isDarwinABI();
|
|
MachineFrameInfo *MFI = MF.getFrameInfo();
|
|
|
|
// If the frame pointer save index hasn't been defined yet.
|
|
if (!FPSI && needsFP(MF)) {
|
|
// Find out what the fix offset of the frame pointer save area.
|
|
int FPOffset = getFramePointerSaveOffset(isPPC64, isDarwinABI);
|
|
// Allocate the frame index for frame pointer save area.
|
|
FPSI = MFI->CreateFixedObject(isPPC64? 8 : 4, FPOffset, true);
|
|
// Save the result.
|
|
FI->setFramePointerSaveIndex(FPSI);
|
|
}
|
|
|
|
int BPSI = FI->getBasePointerSaveIndex();
|
|
if (!BPSI && RegInfo->hasBasePointer(MF)) {
|
|
int BPOffset = getBasePointerSaveOffset(isPPC64, isDarwinABI);
|
|
// Allocate the frame index for the base pointer save area.
|
|
BPSI = MFI->CreateFixedObject(isPPC64? 8 : 4, BPOffset, true);
|
|
// Save the result.
|
|
FI->setBasePointerSaveIndex(BPSI);
|
|
}
|
|
|
|
// Reserve stack space to move the linkage area to in case of a tail call.
|
|
int TCSPDelta = 0;
|
|
if (MF.getTarget().Options.GuaranteedTailCallOpt &&
|
|
(TCSPDelta = FI->getTailCallSPDelta()) < 0) {
|
|
MFI->CreateFixedObject(-1 * TCSPDelta, TCSPDelta, true);
|
|
}
|
|
|
|
// For 32-bit SVR4, allocate the nonvolatile CR spill slot iff the
|
|
// function uses CR 2, 3, or 4.
|
|
if (!isPPC64 && !isDarwinABI &&
|
|
(MRI.isPhysRegUsed(PPC::CR2) ||
|
|
MRI.isPhysRegUsed(PPC::CR3) ||
|
|
MRI.isPhysRegUsed(PPC::CR4))) {
|
|
int FrameIdx = MFI->CreateFixedObject((uint64_t)4, (int64_t)-4, true);
|
|
FI->setCRSpillFrameIndex(FrameIdx);
|
|
}
|
|
}
|
|
|
|
void PPCFrameLowering::processFunctionBeforeFrameFinalized(MachineFunction &MF,
|
|
RegScavenger *RS) const {
|
|
// Early exit if not using the SVR4 ABI.
|
|
if (!Subtarget.isSVR4ABI()) {
|
|
addScavengingSpillSlot(MF, RS);
|
|
return;
|
|
}
|
|
|
|
// Get callee saved register information.
|
|
MachineFrameInfo *FFI = MF.getFrameInfo();
|
|
const std::vector<CalleeSavedInfo> &CSI = FFI->getCalleeSavedInfo();
|
|
|
|
// Early exit if no callee saved registers are modified!
|
|
if (CSI.empty() && !needsFP(MF)) {
|
|
addScavengingSpillSlot(MF, RS);
|
|
return;
|
|
}
|
|
|
|
unsigned MinGPR = PPC::R31;
|
|
unsigned MinG8R = PPC::X31;
|
|
unsigned MinFPR = PPC::F31;
|
|
unsigned MinVR = PPC::V31;
|
|
|
|
bool HasGPSaveArea = false;
|
|
bool HasG8SaveArea = false;
|
|
bool HasFPSaveArea = false;
|
|
bool HasVRSAVESaveArea = false;
|
|
bool HasVRSaveArea = false;
|
|
|
|
SmallVector<CalleeSavedInfo, 18> GPRegs;
|
|
SmallVector<CalleeSavedInfo, 18> G8Regs;
|
|
SmallVector<CalleeSavedInfo, 18> FPRegs;
|
|
SmallVector<CalleeSavedInfo, 18> VRegs;
|
|
|
|
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
|
|
unsigned Reg = CSI[i].getReg();
|
|
if (PPC::GPRCRegClass.contains(Reg)) {
|
|
HasGPSaveArea = true;
|
|
|
|
GPRegs.push_back(CSI[i]);
|
|
|
|
if (Reg < MinGPR) {
|
|
MinGPR = Reg;
|
|
}
|
|
} else if (PPC::G8RCRegClass.contains(Reg)) {
|
|
HasG8SaveArea = true;
|
|
|
|
G8Regs.push_back(CSI[i]);
|
|
|
|
if (Reg < MinG8R) {
|
|
MinG8R = Reg;
|
|
}
|
|
} else if (PPC::F8RCRegClass.contains(Reg)) {
|
|
HasFPSaveArea = true;
|
|
|
|
FPRegs.push_back(CSI[i]);
|
|
|
|
if (Reg < MinFPR) {
|
|
MinFPR = Reg;
|
|
}
|
|
} else if (PPC::CRBITRCRegClass.contains(Reg) ||
|
|
PPC::CRRCRegClass.contains(Reg)) {
|
|
; // do nothing, as we already know whether CRs are spilled
|
|
} else if (PPC::VRSAVERCRegClass.contains(Reg)) {
|
|
HasVRSAVESaveArea = true;
|
|
} else if (PPC::VRRCRegClass.contains(Reg)) {
|
|
HasVRSaveArea = true;
|
|
|
|
VRegs.push_back(CSI[i]);
|
|
|
|
if (Reg < MinVR) {
|
|
MinVR = Reg;
|
|
}
|
|
} else {
|
|
llvm_unreachable("Unknown RegisterClass!");
|
|
}
|
|
}
|
|
|
|
PPCFunctionInfo *PFI = MF.getInfo<PPCFunctionInfo>();
|
|
const TargetRegisterInfo *TRI = MF.getTarget().getRegisterInfo();
|
|
|
|
int64_t LowerBound = 0;
|
|
|
|
// Take into account stack space reserved for tail calls.
|
|
int TCSPDelta = 0;
|
|
if (MF.getTarget().Options.GuaranteedTailCallOpt &&
|
|
(TCSPDelta = PFI->getTailCallSPDelta()) < 0) {
|
|
LowerBound = TCSPDelta;
|
|
}
|
|
|
|
// The Floating-point register save area is right below the back chain word
|
|
// of the previous stack frame.
|
|
if (HasFPSaveArea) {
|
|
for (unsigned i = 0, e = FPRegs.size(); i != e; ++i) {
|
|
int FI = FPRegs[i].getFrameIdx();
|
|
|
|
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
|
|
}
|
|
|
|
LowerBound -= (31 - TRI->getEncodingValue(MinFPR) + 1) * 8;
|
|
}
|
|
|
|
// Check whether the frame pointer register is allocated. If so, make sure it
|
|
// is spilled to the correct offset.
|
|
if (needsFP(MF)) {
|
|
HasGPSaveArea = true;
|
|
|
|
int FI = PFI->getFramePointerSaveIndex();
|
|
assert(FI && "No Frame Pointer Save Slot!");
|
|
|
|
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
|
|
}
|
|
|
|
const PPCRegisterInfo *RegInfo =
|
|
static_cast<const PPCRegisterInfo*>(MF.getTarget().getRegisterInfo());
|
|
if (RegInfo->hasBasePointer(MF)) {
|
|
HasGPSaveArea = true;
|
|
|
|
int FI = PFI->getBasePointerSaveIndex();
|
|
assert(FI && "No Base Pointer Save Slot!");
|
|
|
|
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
|
|
}
|
|
|
|
// General register save area starts right below the Floating-point
|
|
// register save area.
|
|
if (HasGPSaveArea || HasG8SaveArea) {
|
|
// Move general register save area spill slots down, taking into account
|
|
// the size of the Floating-point register save area.
|
|
for (unsigned i = 0, e = GPRegs.size(); i != e; ++i) {
|
|
int FI = GPRegs[i].getFrameIdx();
|
|
|
|
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
|
|
}
|
|
|
|
// Move general register save area spill slots down, taking into account
|
|
// the size of the Floating-point register save area.
|
|
for (unsigned i = 0, e = G8Regs.size(); i != e; ++i) {
|
|
int FI = G8Regs[i].getFrameIdx();
|
|
|
|
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
|
|
}
|
|
|
|
unsigned MinReg =
|
|
std::min<unsigned>(TRI->getEncodingValue(MinGPR),
|
|
TRI->getEncodingValue(MinG8R));
|
|
|
|
if (Subtarget.isPPC64()) {
|
|
LowerBound -= (31 - MinReg + 1) * 8;
|
|
} else {
|
|
LowerBound -= (31 - MinReg + 1) * 4;
|
|
}
|
|
}
|
|
|
|
// For 32-bit only, the CR save area is below the general register
|
|
// save area. For 64-bit SVR4, the CR save area is addressed relative
|
|
// to the stack pointer and hence does not need an adjustment here.
|
|
// Only CR2 (the first nonvolatile spilled) has an associated frame
|
|
// index so that we have a single uniform save area.
|
|
if (spillsCR(MF) && !(Subtarget.isPPC64() && Subtarget.isSVR4ABI())) {
|
|
// Adjust the frame index of the CR spill slot.
|
|
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
|
|
unsigned Reg = CSI[i].getReg();
|
|
|
|
if ((Subtarget.isSVR4ABI() && Reg == PPC::CR2)
|
|
// Leave Darwin logic as-is.
|
|
|| (!Subtarget.isSVR4ABI() &&
|
|
(PPC::CRBITRCRegClass.contains(Reg) ||
|
|
PPC::CRRCRegClass.contains(Reg)))) {
|
|
int FI = CSI[i].getFrameIdx();
|
|
|
|
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
|
|
}
|
|
}
|
|
|
|
LowerBound -= 4; // The CR save area is always 4 bytes long.
|
|
}
|
|
|
|
if (HasVRSAVESaveArea) {
|
|
// FIXME SVR4: Is it actually possible to have multiple elements in CSI
|
|
// which have the VRSAVE register class?
|
|
// Adjust the frame index of the VRSAVE spill slot.
|
|
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
|
|
unsigned Reg = CSI[i].getReg();
|
|
|
|
if (PPC::VRSAVERCRegClass.contains(Reg)) {
|
|
int FI = CSI[i].getFrameIdx();
|
|
|
|
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
|
|
}
|
|
}
|
|
|
|
LowerBound -= 4; // The VRSAVE save area is always 4 bytes long.
|
|
}
|
|
|
|
if (HasVRSaveArea) {
|
|
// Insert alignment padding, we need 16-byte alignment.
|
|
LowerBound = (LowerBound - 15) & ~(15);
|
|
|
|
for (unsigned i = 0, e = VRegs.size(); i != e; ++i) {
|
|
int FI = VRegs[i].getFrameIdx();
|
|
|
|
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
|
|
}
|
|
}
|
|
|
|
addScavengingSpillSlot(MF, RS);
|
|
}
|
|
|
|
void
|
|
PPCFrameLowering::addScavengingSpillSlot(MachineFunction &MF,
|
|
RegScavenger *RS) const {
|
|
// Reserve a slot closest to SP or frame pointer if we have a dynalloc or
|
|
// a large stack, which will require scavenging a register to materialize a
|
|
// large offset.
|
|
|
|
// We need to have a scavenger spill slot for spills if the frame size is
|
|
// large. In case there is no free register for large-offset addressing,
|
|
// this slot is used for the necessary emergency spill. Also, we need the
|
|
// slot for dynamic stack allocations.
|
|
|
|
// The scavenger might be invoked if the frame offset does not fit into
|
|
// the 16-bit immediate. We don't know the complete frame size here
|
|
// because we've not yet computed callee-saved register spills or the
|
|
// needed alignment padding.
|
|
unsigned StackSize = determineFrameLayout(MF, false, true);
|
|
MachineFrameInfo *MFI = MF.getFrameInfo();
|
|
if (MFI->hasVarSizedObjects() || spillsCR(MF) || spillsVRSAVE(MF) ||
|
|
hasNonRISpills(MF) || (hasSpills(MF) && !isInt<16>(StackSize))) {
|
|
const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
|
|
const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
|
|
const TargetRegisterClass *RC = Subtarget.isPPC64() ? G8RC : GPRC;
|
|
RS->addScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
|
|
RC->getAlignment(),
|
|
false));
|
|
|
|
// Might we have over-aligned allocas?
|
|
bool HasAlVars = MFI->hasVarSizedObjects() &&
|
|
MFI->getMaxAlignment() > getStackAlignment();
|
|
|
|
// These kinds of spills might need two registers.
|
|
if (spillsCR(MF) || spillsVRSAVE(MF) || HasAlVars)
|
|
RS->addScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
|
|
RC->getAlignment(),
|
|
false));
|
|
|
|
}
|
|
}
|
|
|
|
bool
|
|
PPCFrameLowering::spillCalleeSavedRegisters(MachineBasicBlock &MBB,
|
|
MachineBasicBlock::iterator MI,
|
|
const std::vector<CalleeSavedInfo> &CSI,
|
|
const TargetRegisterInfo *TRI) const {
|
|
|
|
// Currently, this function only handles SVR4 32- and 64-bit ABIs.
|
|
// Return false otherwise to maintain pre-existing behavior.
|
|
if (!Subtarget.isSVR4ABI())
|
|
return false;
|
|
|
|
MachineFunction *MF = MBB.getParent();
|
|
const PPCInstrInfo &TII =
|
|
*static_cast<const PPCInstrInfo*>(MF->getTarget().getInstrInfo());
|
|
DebugLoc DL;
|
|
bool CRSpilled = false;
|
|
MachineInstrBuilder CRMIB;
|
|
|
|
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
|
|
unsigned Reg = CSI[i].getReg();
|
|
// Only Darwin actually uses the VRSAVE register, but it can still appear
|
|
// here if, for example, @llvm.eh.unwind.init() is used. If we're not on
|
|
// Darwin, ignore it.
|
|
if (Reg == PPC::VRSAVE && !Subtarget.isDarwinABI())
|
|
continue;
|
|
|
|
// CR2 through CR4 are the nonvolatile CR fields.
|
|
bool IsCRField = PPC::CR2 <= Reg && Reg <= PPC::CR4;
|
|
|
|
// Add the callee-saved register as live-in; it's killed at the spill.
|
|
MBB.addLiveIn(Reg);
|
|
|
|
if (CRSpilled && IsCRField) {
|
|
CRMIB.addReg(Reg, RegState::ImplicitKill);
|
|
continue;
|
|
}
|
|
|
|
// Insert the spill to the stack frame.
|
|
if (IsCRField) {
|
|
PPCFunctionInfo *FuncInfo = MF->getInfo<PPCFunctionInfo>();
|
|
if (Subtarget.isPPC64()) {
|
|
// The actual spill will happen at the start of the prologue.
|
|
FuncInfo->addMustSaveCR(Reg);
|
|
} else {
|
|
CRSpilled = true;
|
|
FuncInfo->setSpillsCR();
|
|
|
|
// 32-bit: FP-relative. Note that we made sure CR2-CR4 all have
|
|
// the same frame index in PPCRegisterInfo::hasReservedSpillSlot.
|
|
CRMIB = BuildMI(*MF, DL, TII.get(PPC::MFCR), PPC::R12)
|
|
.addReg(Reg, RegState::ImplicitKill);
|
|
|
|
MBB.insert(MI, CRMIB);
|
|
MBB.insert(MI, addFrameReference(BuildMI(*MF, DL, TII.get(PPC::STW))
|
|
.addReg(PPC::R12,
|
|
getKillRegState(true)),
|
|
CSI[i].getFrameIdx()));
|
|
}
|
|
} else {
|
|
const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
|
|
TII.storeRegToStackSlot(MBB, MI, Reg, true,
|
|
CSI[i].getFrameIdx(), RC, TRI);
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static void
|
|
restoreCRs(bool isPPC64, bool is31,
|
|
bool CR2Spilled, bool CR3Spilled, bool CR4Spilled,
|
|
MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
|
|
const std::vector<CalleeSavedInfo> &CSI, unsigned CSIIndex) {
|
|
|
|
MachineFunction *MF = MBB.getParent();
|
|
const PPCInstrInfo &TII =
|
|
*static_cast<const PPCInstrInfo*>(MF->getTarget().getInstrInfo());
|
|
DebugLoc DL;
|
|
unsigned RestoreOp, MoveReg;
|
|
|
|
if (isPPC64)
|
|
// This is handled during epilogue generation.
|
|
return;
|
|
else {
|
|
// 32-bit: FP-relative
|
|
MBB.insert(MI, addFrameReference(BuildMI(*MF, DL, TII.get(PPC::LWZ),
|
|
PPC::R12),
|
|
CSI[CSIIndex].getFrameIdx()));
|
|
RestoreOp = PPC::MTOCRF;
|
|
MoveReg = PPC::R12;
|
|
}
|
|
|
|
if (CR2Spilled)
|
|
MBB.insert(MI, BuildMI(*MF, DL, TII.get(RestoreOp), PPC::CR2)
|
|
.addReg(MoveReg, getKillRegState(!CR3Spilled && !CR4Spilled)));
|
|
|
|
if (CR3Spilled)
|
|
MBB.insert(MI, BuildMI(*MF, DL, TII.get(RestoreOp), PPC::CR3)
|
|
.addReg(MoveReg, getKillRegState(!CR4Spilled)));
|
|
|
|
if (CR4Spilled)
|
|
MBB.insert(MI, BuildMI(*MF, DL, TII.get(RestoreOp), PPC::CR4)
|
|
.addReg(MoveReg, getKillRegState(true)));
|
|
}
|
|
|
|
void PPCFrameLowering::
|
|
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
|
|
MachineBasicBlock::iterator I) const {
|
|
const PPCInstrInfo &TII =
|
|
*static_cast<const PPCInstrInfo*>(MF.getTarget().getInstrInfo());
|
|
if (MF.getTarget().Options.GuaranteedTailCallOpt &&
|
|
I->getOpcode() == PPC::ADJCALLSTACKUP) {
|
|
// Add (actually subtract) back the amount the callee popped on return.
|
|
if (int CalleeAmt = I->getOperand(1).getImm()) {
|
|
bool is64Bit = Subtarget.isPPC64();
|
|
CalleeAmt *= -1;
|
|
unsigned StackReg = is64Bit ? PPC::X1 : PPC::R1;
|
|
unsigned TmpReg = is64Bit ? PPC::X0 : PPC::R0;
|
|
unsigned ADDIInstr = is64Bit ? PPC::ADDI8 : PPC::ADDI;
|
|
unsigned ADDInstr = is64Bit ? PPC::ADD8 : PPC::ADD4;
|
|
unsigned LISInstr = is64Bit ? PPC::LIS8 : PPC::LIS;
|
|
unsigned ORIInstr = is64Bit ? PPC::ORI8 : PPC::ORI;
|
|
MachineInstr *MI = I;
|
|
DebugLoc dl = MI->getDebugLoc();
|
|
|
|
if (isInt<16>(CalleeAmt)) {
|
|
BuildMI(MBB, I, dl, TII.get(ADDIInstr), StackReg)
|
|
.addReg(StackReg, RegState::Kill)
|
|
.addImm(CalleeAmt);
|
|
} else {
|
|
MachineBasicBlock::iterator MBBI = I;
|
|
BuildMI(MBB, MBBI, dl, TII.get(LISInstr), TmpReg)
|
|
.addImm(CalleeAmt >> 16);
|
|
BuildMI(MBB, MBBI, dl, TII.get(ORIInstr), TmpReg)
|
|
.addReg(TmpReg, RegState::Kill)
|
|
.addImm(CalleeAmt & 0xFFFF);
|
|
BuildMI(MBB, MBBI, dl, TII.get(ADDInstr), StackReg)
|
|
.addReg(StackReg, RegState::Kill)
|
|
.addReg(TmpReg);
|
|
}
|
|
}
|
|
}
|
|
// Simply discard ADJCALLSTACKDOWN, ADJCALLSTACKUP instructions.
|
|
MBB.erase(I);
|
|
}
|
|
|
|
bool
|
|
PPCFrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
|
|
MachineBasicBlock::iterator MI,
|
|
const std::vector<CalleeSavedInfo> &CSI,
|
|
const TargetRegisterInfo *TRI) const {
|
|
|
|
// Currently, this function only handles SVR4 32- and 64-bit ABIs.
|
|
// Return false otherwise to maintain pre-existing behavior.
|
|
if (!Subtarget.isSVR4ABI())
|
|
return false;
|
|
|
|
MachineFunction *MF = MBB.getParent();
|
|
const PPCInstrInfo &TII =
|
|
*static_cast<const PPCInstrInfo*>(MF->getTarget().getInstrInfo());
|
|
bool CR2Spilled = false;
|
|
bool CR3Spilled = false;
|
|
bool CR4Spilled = false;
|
|
unsigned CSIIndex = 0;
|
|
|
|
// Initialize insertion-point logic; we will be restoring in reverse
|
|
// order of spill.
|
|
MachineBasicBlock::iterator I = MI, BeforeI = I;
|
|
bool AtStart = I == MBB.begin();
|
|
|
|
if (!AtStart)
|
|
--BeforeI;
|
|
|
|
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
|
|
unsigned Reg = CSI[i].getReg();
|
|
|
|
// Only Darwin actually uses the VRSAVE register, but it can still appear
|
|
// here if, for example, @llvm.eh.unwind.init() is used. If we're not on
|
|
// Darwin, ignore it.
|
|
if (Reg == PPC::VRSAVE && !Subtarget.isDarwinABI())
|
|
continue;
|
|
|
|
if (Reg == PPC::CR2) {
|
|
CR2Spilled = true;
|
|
// The spill slot is associated only with CR2, which is the
|
|
// first nonvolatile spilled. Save it here.
|
|
CSIIndex = i;
|
|
continue;
|
|
} else if (Reg == PPC::CR3) {
|
|
CR3Spilled = true;
|
|
continue;
|
|
} else if (Reg == PPC::CR4) {
|
|
CR4Spilled = true;
|
|
continue;
|
|
} else {
|
|
// When we first encounter a non-CR register after seeing at
|
|
// least one CR register, restore all spilled CRs together.
|
|
if ((CR2Spilled || CR3Spilled || CR4Spilled)
|
|
&& !(PPC::CR2 <= Reg && Reg <= PPC::CR4)) {
|
|
bool is31 = needsFP(*MF);
|
|
restoreCRs(Subtarget.isPPC64(), is31,
|
|
CR2Spilled, CR3Spilled, CR4Spilled,
|
|
MBB, I, CSI, CSIIndex);
|
|
CR2Spilled = CR3Spilled = CR4Spilled = false;
|
|
}
|
|
|
|
// Default behavior for non-CR saves.
|
|
const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
|
|
TII.loadRegFromStackSlot(MBB, I, Reg, CSI[i].getFrameIdx(),
|
|
RC, TRI);
|
|
assert(I != MBB.begin() &&
|
|
"loadRegFromStackSlot didn't insert any code!");
|
|
}
|
|
|
|
// Insert in reverse order.
|
|
if (AtStart)
|
|
I = MBB.begin();
|
|
else {
|
|
I = BeforeI;
|
|
++I;
|
|
}
|
|
}
|
|
|
|
// If we haven't yet spilled the CRs, do so now.
|
|
if (CR2Spilled || CR3Spilled || CR4Spilled) {
|
|
bool is31 = needsFP(*MF);
|
|
restoreCRs(Subtarget.isPPC64(), is31, CR2Spilled, CR3Spilled, CR4Spilled,
|
|
MBB, I, CSI, CSIIndex);
|
|
}
|
|
|
|
return true;
|
|
}
|