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	expanding pseudo LOAD_STATCK_GUARD using instructions that are normally used in pic mode. This patch fixes the bug. <rdar://problem/17886592> git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214614 91177308-0d34-0410-b5e6-96231b3b80d8
		
			
				
	
	
		
			640 lines
		
	
	
		
			21 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			640 lines
		
	
	
		
			21 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| //===-- Thumb2InstrInfo.cpp - Thumb-2 Instruction 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 Thumb-2 implementation of the TargetInstrInfo class.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #include "Thumb2InstrInfo.h"
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| #include "ARMConstantPoolValue.h"
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| #include "ARMMachineFunctionInfo.h"
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| #include "MCTargetDesc/ARMAddressingModes.h"
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| #include "llvm/CodeGen/MachineFrameInfo.h"
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| #include "llvm/CodeGen/MachineInstrBuilder.h"
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| #include "llvm/CodeGen/MachineMemOperand.h"
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| #include "llvm/CodeGen/MachineRegisterInfo.h"
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| #include "llvm/MC/MCInst.h"
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| #include "llvm/Support/CommandLine.h"
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| 
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| using namespace llvm;
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| 
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| static cl::opt<bool>
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| OldT2IfCvt("old-thumb2-ifcvt", cl::Hidden,
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|            cl::desc("Use old-style Thumb2 if-conversion heuristics"),
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|            cl::init(false));
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| 
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| Thumb2InstrInfo::Thumb2InstrInfo(const ARMSubtarget &STI)
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|   : ARMBaseInstrInfo(STI), RI(STI) {
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| }
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| 
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| /// getNoopForMachoTarget - Return the noop instruction to use for a noop.
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| void Thumb2InstrInfo::getNoopForMachoTarget(MCInst &NopInst) const {
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|   NopInst.setOpcode(ARM::tHINT);
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|   NopInst.addOperand(MCOperand::CreateImm(0));
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|   NopInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
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|   NopInst.addOperand(MCOperand::CreateReg(0));
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| }
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| 
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| unsigned Thumb2InstrInfo::getUnindexedOpcode(unsigned Opc) const {
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|   // FIXME
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|   return 0;
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| }
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| 
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| void
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| Thumb2InstrInfo::ReplaceTailWithBranchTo(MachineBasicBlock::iterator Tail,
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|                                          MachineBasicBlock *NewDest) const {
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|   MachineBasicBlock *MBB = Tail->getParent();
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|   ARMFunctionInfo *AFI = MBB->getParent()->getInfo<ARMFunctionInfo>();
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|   if (!AFI->hasITBlocks()) {
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|     TargetInstrInfo::ReplaceTailWithBranchTo(Tail, NewDest);
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|     return;
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|   }
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| 
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|   // If the first instruction of Tail is predicated, we may have to update
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|   // the IT instruction.
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|   unsigned PredReg = 0;
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|   ARMCC::CondCodes CC = getInstrPredicate(Tail, PredReg);
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|   MachineBasicBlock::iterator MBBI = Tail;
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|   if (CC != ARMCC::AL)
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|     // Expecting at least the t2IT instruction before it.
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|     --MBBI;
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| 
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|   // Actually replace the tail.
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|   TargetInstrInfo::ReplaceTailWithBranchTo(Tail, NewDest);
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| 
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|   // Fix up IT.
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|   if (CC != ARMCC::AL) {
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|     MachineBasicBlock::iterator E = MBB->begin();
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|     unsigned Count = 4; // At most 4 instructions in an IT block.
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|     while (Count && MBBI != E) {
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|       if (MBBI->isDebugValue()) {
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|         --MBBI;
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|         continue;
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|       }
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|       if (MBBI->getOpcode() == ARM::t2IT) {
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|         unsigned Mask = MBBI->getOperand(1).getImm();
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|         if (Count == 4)
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|           MBBI->eraseFromParent();
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|         else {
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|           unsigned MaskOn = 1 << Count;
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|           unsigned MaskOff = ~(MaskOn - 1);
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|           MBBI->getOperand(1).setImm((Mask & MaskOff) | MaskOn);
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|         }
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|         return;
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|       }
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|       --MBBI;
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|       --Count;
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|     }
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| 
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|     // Ctrl flow can reach here if branch folding is run before IT block
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|     // formation pass.
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|   }
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| }
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| 
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| bool
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| Thumb2InstrInfo::isLegalToSplitMBBAt(MachineBasicBlock &MBB,
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|                                      MachineBasicBlock::iterator MBBI) const {
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|   while (MBBI->isDebugValue()) {
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|     ++MBBI;
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|     if (MBBI == MBB.end())
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|       return false;
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|   }
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| 
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|   unsigned PredReg = 0;
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|   return getITInstrPredicate(MBBI, PredReg) == ARMCC::AL;
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| }
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| 
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| void Thumb2InstrInfo::copyPhysReg(MachineBasicBlock &MBB,
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|                                   MachineBasicBlock::iterator I, DebugLoc DL,
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|                                   unsigned DestReg, unsigned SrcReg,
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|                                   bool KillSrc) const {
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|   // Handle SPR, DPR, and QPR copies.
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|   if (!ARM::GPRRegClass.contains(DestReg, SrcReg))
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|     return ARMBaseInstrInfo::copyPhysReg(MBB, I, DL, DestReg, SrcReg, KillSrc);
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| 
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|   AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::tMOVr), DestReg)
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|     .addReg(SrcReg, getKillRegState(KillSrc)));
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| }
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| 
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| void Thumb2InstrInfo::
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| storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
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|                     unsigned SrcReg, bool isKill, int FI,
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|                     const TargetRegisterClass *RC,
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|                     const TargetRegisterInfo *TRI) const {
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|   DebugLoc DL;
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|   if (I != MBB.end()) DL = I->getDebugLoc();
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| 
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|   MachineFunction &MF = *MBB.getParent();
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|   MachineFrameInfo &MFI = *MF.getFrameInfo();
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|   MachineMemOperand *MMO =
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|     MF.getMachineMemOperand(MachinePointerInfo::getFixedStack(FI),
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|                             MachineMemOperand::MOStore,
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|                             MFI.getObjectSize(FI),
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|                             MFI.getObjectAlignment(FI));
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| 
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|   if (RC == &ARM::GPRRegClass   || RC == &ARM::tGPRRegClass ||
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|       RC == &ARM::tcGPRRegClass || RC == &ARM::rGPRRegClass ||
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|       RC == &ARM::GPRnopcRegClass) {
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|     AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::t2STRi12))
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|                    .addReg(SrcReg, getKillRegState(isKill))
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|                    .addFrameIndex(FI).addImm(0).addMemOperand(MMO));
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|     return;
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|   }
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| 
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|   if (ARM::GPRPairRegClass.hasSubClassEq(RC)) {
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|     // Thumb2 STRD expects its dest-registers to be in rGPR. Not a problem for
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|     // gsub_0, but needs an extra constraint for gsub_1 (which could be sp
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|     // otherwise).
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|     MachineRegisterInfo *MRI = &MF.getRegInfo();
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|     MRI->constrainRegClass(SrcReg, &ARM::GPRPair_with_gsub_1_in_rGPRRegClass);
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| 
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|     MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::t2STRDi8));
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|     AddDReg(MIB, SrcReg, ARM::gsub_0, getKillRegState(isKill), TRI);
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|     AddDReg(MIB, SrcReg, ARM::gsub_1, 0, TRI);
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|     MIB.addFrameIndex(FI).addImm(0).addMemOperand(MMO);
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|     AddDefaultPred(MIB);
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|     return;
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|   }
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| 
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|   ARMBaseInstrInfo::storeRegToStackSlot(MBB, I, SrcReg, isKill, FI, RC, TRI);
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| }
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| 
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| void Thumb2InstrInfo::
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| loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
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|                      unsigned DestReg, int FI,
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|                      const TargetRegisterClass *RC,
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|                      const TargetRegisterInfo *TRI) const {
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|   MachineFunction &MF = *MBB.getParent();
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|   MachineFrameInfo &MFI = *MF.getFrameInfo();
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|   MachineMemOperand *MMO =
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|     MF.getMachineMemOperand(MachinePointerInfo::getFixedStack(FI),
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|                             MachineMemOperand::MOLoad,
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|                             MFI.getObjectSize(FI),
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|                             MFI.getObjectAlignment(FI));
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|   DebugLoc DL;
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|   if (I != MBB.end()) DL = I->getDebugLoc();
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| 
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|   if (RC == &ARM::GPRRegClass   || RC == &ARM::tGPRRegClass ||
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|       RC == &ARM::tcGPRRegClass || RC == &ARM::rGPRRegClass ||
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|       RC == &ARM::GPRnopcRegClass) {
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|     AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::t2LDRi12), DestReg)
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|                    .addFrameIndex(FI).addImm(0).addMemOperand(MMO));
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|     return;
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|   }
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| 
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|   if (ARM::GPRPairRegClass.hasSubClassEq(RC)) {
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|     // Thumb2 LDRD expects its dest-registers to be in rGPR. Not a problem for
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|     // gsub_0, but needs an extra constraint for gsub_1 (which could be sp
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|     // otherwise).
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|     MachineRegisterInfo *MRI = &MF.getRegInfo();
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|     MRI->constrainRegClass(DestReg, &ARM::GPRPair_with_gsub_1_in_rGPRRegClass);
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| 
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|     MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::t2LDRDi8));
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|     AddDReg(MIB, DestReg, ARM::gsub_0, RegState::DefineNoRead, TRI);
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|     AddDReg(MIB, DestReg, ARM::gsub_1, RegState::DefineNoRead, TRI);
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|     MIB.addFrameIndex(FI).addImm(0).addMemOperand(MMO);
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|     AddDefaultPred(MIB);
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| 
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|     if (TargetRegisterInfo::isPhysicalRegister(DestReg))
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|       MIB.addReg(DestReg, RegState::ImplicitDefine);
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|     return;
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|   }
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| 
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|   ARMBaseInstrInfo::loadRegFromStackSlot(MBB, I, DestReg, FI, RC, TRI);
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| }
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| 
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| void
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| Thumb2InstrInfo::expandLoadStackGuard(MachineBasicBlock::iterator MI,
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|                                       Reloc::Model RM) const {
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|   if (RM == Reloc::PIC_)
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|     expandLoadStackGuardBase(MI, ARM::t2MOV_ga_pcrel, ARM::t2LDRi12, RM);
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|   else
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|     expandLoadStackGuardBase(MI, ARM::t2MOVi32imm, ARM::t2LDRi12, RM);
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| }
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| 
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| void llvm::emitT2RegPlusImmediate(MachineBasicBlock &MBB,
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|                                MachineBasicBlock::iterator &MBBI, DebugLoc dl,
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|                                unsigned DestReg, unsigned BaseReg, int NumBytes,
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|                                ARMCC::CondCodes Pred, unsigned PredReg,
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|                                const ARMBaseInstrInfo &TII, unsigned MIFlags) {
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|   if (NumBytes == 0 && DestReg != BaseReg) {
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|     BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), DestReg)
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|       .addReg(BaseReg, RegState::Kill)
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|       .addImm((unsigned)Pred).addReg(PredReg).setMIFlags(MIFlags);
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|     return;
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|   }
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| 
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|   bool isSub = NumBytes < 0;
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|   if (isSub) NumBytes = -NumBytes;
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| 
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|   // If profitable, use a movw or movt to materialize the offset.
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|   // FIXME: Use the scavenger to grab a scratch register.
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|   if (DestReg != ARM::SP && DestReg != BaseReg &&
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|       NumBytes >= 4096 &&
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|       ARM_AM::getT2SOImmVal(NumBytes) == -1) {
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|     bool Fits = false;
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|     if (NumBytes < 65536) {
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|       // Use a movw to materialize the 16-bit constant.
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|       BuildMI(MBB, MBBI, dl, TII.get(ARM::t2MOVi16), DestReg)
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|         .addImm(NumBytes)
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|         .addImm((unsigned)Pred).addReg(PredReg).setMIFlags(MIFlags);
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|       Fits = true;
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|     } else if ((NumBytes & 0xffff) == 0) {
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|       // Use a movt to materialize the 32-bit constant.
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|       BuildMI(MBB, MBBI, dl, TII.get(ARM::t2MOVTi16), DestReg)
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|         .addReg(DestReg)
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|         .addImm(NumBytes >> 16)
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|         .addImm((unsigned)Pred).addReg(PredReg).setMIFlags(MIFlags);
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|       Fits = true;
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|     }
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| 
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|     if (Fits) {
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|       if (isSub) {
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|         BuildMI(MBB, MBBI, dl, TII.get(ARM::t2SUBrr), DestReg)
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|           .addReg(BaseReg, RegState::Kill)
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|           .addReg(DestReg, RegState::Kill)
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|           .addImm((unsigned)Pred).addReg(PredReg).addReg(0)
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|           .setMIFlags(MIFlags);
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|       } else {
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|         BuildMI(MBB, MBBI, dl, TII.get(ARM::t2ADDrr), DestReg)
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|           .addReg(DestReg, RegState::Kill)
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|           .addReg(BaseReg, RegState::Kill)
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|           .addImm((unsigned)Pred).addReg(PredReg).addReg(0)
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|           .setMIFlags(MIFlags);
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|       }
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|       return;
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|     }
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|   }
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| 
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|   while (NumBytes) {
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|     unsigned ThisVal = NumBytes;
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|     unsigned Opc = 0;
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|     if (DestReg == ARM::SP && BaseReg != ARM::SP) {
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|       // mov sp, rn. Note t2MOVr cannot be used.
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|       AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr),DestReg)
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|         .addReg(BaseReg).setMIFlags(MIFlags));
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|       BaseReg = ARM::SP;
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|       continue;
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|     }
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| 
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|     bool HasCCOut = true;
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|     if (BaseReg == ARM::SP) {
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|       // sub sp, sp, #imm7
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|       if (DestReg == ARM::SP && (ThisVal < ((1 << 7)-1) * 4)) {
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|         assert((ThisVal & 3) == 0 && "Stack update is not multiple of 4?");
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|         Opc = isSub ? ARM::tSUBspi : ARM::tADDspi;
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|         AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg)
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|           .addReg(BaseReg).addImm(ThisVal/4).setMIFlags(MIFlags));
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|         NumBytes = 0;
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|         continue;
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|       }
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| 
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|       // sub rd, sp, so_imm
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|       Opc = isSub ? ARM::t2SUBri : ARM::t2ADDri;
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|       if (ARM_AM::getT2SOImmVal(NumBytes) != -1) {
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|         NumBytes = 0;
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|       } else {
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|         // FIXME: Move this to ARMAddressingModes.h?
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|         unsigned RotAmt = countLeadingZeros(ThisVal);
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|         ThisVal = ThisVal & ARM_AM::rotr32(0xff000000U, RotAmt);
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|         NumBytes &= ~ThisVal;
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|         assert(ARM_AM::getT2SOImmVal(ThisVal) != -1 &&
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|                "Bit extraction didn't work?");
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|       }
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|     } else {
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|       assert(DestReg != ARM::SP && BaseReg != ARM::SP);
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|       Opc = isSub ? ARM::t2SUBri : ARM::t2ADDri;
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|       if (ARM_AM::getT2SOImmVal(NumBytes) != -1) {
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|         NumBytes = 0;
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|       } else if (ThisVal < 4096) {
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|         Opc = isSub ? ARM::t2SUBri12 : ARM::t2ADDri12;
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|         HasCCOut = false;
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|         NumBytes = 0;
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|       } else {
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|         // FIXME: Move this to ARMAddressingModes.h?
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|         unsigned RotAmt = countLeadingZeros(ThisVal);
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|         ThisVal = ThisVal & ARM_AM::rotr32(0xff000000U, RotAmt);
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|         NumBytes &= ~ThisVal;
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|         assert(ARM_AM::getT2SOImmVal(ThisVal) != -1 &&
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|                "Bit extraction didn't work?");
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|       }
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|     }
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| 
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|     // Build the new ADD / SUB.
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|     MachineInstrBuilder MIB =
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|       AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg)
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|                      .addReg(BaseReg, RegState::Kill)
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|                      .addImm(ThisVal)).setMIFlags(MIFlags);
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|     if (HasCCOut)
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|       AddDefaultCC(MIB);
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| 
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|     BaseReg = DestReg;
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|   }
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| }
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| 
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| static unsigned
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| negativeOffsetOpcode(unsigned opcode)
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| {
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|   switch (opcode) {
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|   case ARM::t2LDRi12:   return ARM::t2LDRi8;
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|   case ARM::t2LDRHi12:  return ARM::t2LDRHi8;
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|   case ARM::t2LDRBi12:  return ARM::t2LDRBi8;
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|   case ARM::t2LDRSHi12: return ARM::t2LDRSHi8;
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|   case ARM::t2LDRSBi12: return ARM::t2LDRSBi8;
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|   case ARM::t2STRi12:   return ARM::t2STRi8;
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|   case ARM::t2STRBi12:  return ARM::t2STRBi8;
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|   case ARM::t2STRHi12:  return ARM::t2STRHi8;
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|   case ARM::t2PLDi12:   return ARM::t2PLDi8;
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| 
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|   case ARM::t2LDRi8:
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|   case ARM::t2LDRHi8:
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|   case ARM::t2LDRBi8:
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|   case ARM::t2LDRSHi8:
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|   case ARM::t2LDRSBi8:
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|   case ARM::t2STRi8:
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|   case ARM::t2STRBi8:
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|   case ARM::t2STRHi8:
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|   case ARM::t2PLDi8:
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|     return opcode;
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| 
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|   default:
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|     break;
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|   }
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| 
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|   return 0;
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| }
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| 
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| static unsigned
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| positiveOffsetOpcode(unsigned opcode)
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| {
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|   switch (opcode) {
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|   case ARM::t2LDRi8:   return ARM::t2LDRi12;
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|   case ARM::t2LDRHi8:  return ARM::t2LDRHi12;
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|   case ARM::t2LDRBi8:  return ARM::t2LDRBi12;
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|   case ARM::t2LDRSHi8: return ARM::t2LDRSHi12;
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|   case ARM::t2LDRSBi8: return ARM::t2LDRSBi12;
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|   case ARM::t2STRi8:   return ARM::t2STRi12;
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|   case ARM::t2STRBi8:  return ARM::t2STRBi12;
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|   case ARM::t2STRHi8:  return ARM::t2STRHi12;
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|   case ARM::t2PLDi8:   return ARM::t2PLDi12;
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| 
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|   case ARM::t2LDRi12:
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|   case ARM::t2LDRHi12:
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|   case ARM::t2LDRBi12:
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|   case ARM::t2LDRSHi12:
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|   case ARM::t2LDRSBi12:
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|   case ARM::t2STRi12:
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|   case ARM::t2STRBi12:
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|   case ARM::t2STRHi12:
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|   case ARM::t2PLDi12:
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|     return opcode;
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| 
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|   default:
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|     break;
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|   }
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| 
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|   return 0;
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| }
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| 
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| static unsigned
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| immediateOffsetOpcode(unsigned opcode)
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| {
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|   switch (opcode) {
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|   case ARM::t2LDRs:   return ARM::t2LDRi12;
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|   case ARM::t2LDRHs:  return ARM::t2LDRHi12;
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|   case ARM::t2LDRBs:  return ARM::t2LDRBi12;
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|   case ARM::t2LDRSHs: return ARM::t2LDRSHi12;
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|   case ARM::t2LDRSBs: return ARM::t2LDRSBi12;
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|   case ARM::t2STRs:   return ARM::t2STRi12;
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|   case ARM::t2STRBs:  return ARM::t2STRBi12;
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|   case ARM::t2STRHs:  return ARM::t2STRHi12;
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|   case ARM::t2PLDs:   return ARM::t2PLDi12;
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| 
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|   case ARM::t2LDRi12:
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|   case ARM::t2LDRHi12:
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|   case ARM::t2LDRBi12:
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|   case ARM::t2LDRSHi12:
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|   case ARM::t2LDRSBi12:
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|   case ARM::t2STRi12:
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|   case ARM::t2STRBi12:
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|   case ARM::t2STRHi12:
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|   case ARM::t2PLDi12:
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|   case ARM::t2LDRi8:
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|   case ARM::t2LDRHi8:
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|   case ARM::t2LDRBi8:
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|   case ARM::t2LDRSHi8:
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|   case ARM::t2LDRSBi8:
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|   case ARM::t2STRi8:
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|   case ARM::t2STRBi8:
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|   case ARM::t2STRHi8:
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|   case ARM::t2PLDi8:
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|     return opcode;
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| 
 | |
|   default:
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|     break;
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|   }
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| 
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| bool llvm::rewriteT2FrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
 | |
|                                unsigned FrameReg, int &Offset,
 | |
|                                const ARMBaseInstrInfo &TII) {
 | |
|   unsigned Opcode = MI.getOpcode();
 | |
|   const MCInstrDesc &Desc = MI.getDesc();
 | |
|   unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
 | |
|   bool isSub = false;
 | |
| 
 | |
|   // Memory operands in inline assembly always use AddrModeT2_i12.
 | |
|   if (Opcode == ARM::INLINEASM)
 | |
|     AddrMode = ARMII::AddrModeT2_i12; // FIXME. mode for thumb2?
 | |
| 
 | |
|   if (Opcode == ARM::t2ADDri || Opcode == ARM::t2ADDri12) {
 | |
|     Offset += MI.getOperand(FrameRegIdx+1).getImm();
 | |
| 
 | |
|     unsigned PredReg;
 | |
|     if (Offset == 0 && getInstrPredicate(&MI, PredReg) == ARMCC::AL) {
 | |
|       // Turn it into a move.
 | |
|       MI.setDesc(TII.get(ARM::tMOVr));
 | |
|       MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
 | |
|       // Remove offset and remaining explicit predicate operands.
 | |
|       do MI.RemoveOperand(FrameRegIdx+1);
 | |
|       while (MI.getNumOperands() > FrameRegIdx+1);
 | |
|       MachineInstrBuilder MIB(*MI.getParent()->getParent(), &MI);
 | |
|       AddDefaultPred(MIB);
 | |
|       return true;
 | |
|     }
 | |
| 
 | |
|     bool HasCCOut = Opcode != ARM::t2ADDri12;
 | |
| 
 | |
|     if (Offset < 0) {
 | |
|       Offset = -Offset;
 | |
|       isSub = true;
 | |
|       MI.setDesc(TII.get(ARM::t2SUBri));
 | |
|     } else {
 | |
|       MI.setDesc(TII.get(ARM::t2ADDri));
 | |
|     }
 | |
| 
 | |
|     // Common case: small offset, fits into instruction.
 | |
|     if (ARM_AM::getT2SOImmVal(Offset) != -1) {
 | |
|       MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
 | |
|       MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset);
 | |
|       // Add cc_out operand if the original instruction did not have one.
 | |
|       if (!HasCCOut)
 | |
|         MI.addOperand(MachineOperand::CreateReg(0, false));
 | |
|       Offset = 0;
 | |
|       return true;
 | |
|     }
 | |
|     // Another common case: imm12.
 | |
|     if (Offset < 4096 &&
 | |
|         (!HasCCOut || MI.getOperand(MI.getNumOperands()-1).getReg() == 0)) {
 | |
|       unsigned NewOpc = isSub ? ARM::t2SUBri12 : ARM::t2ADDri12;
 | |
|       MI.setDesc(TII.get(NewOpc));
 | |
|       MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
 | |
|       MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset);
 | |
|       // Remove the cc_out operand.
 | |
|       if (HasCCOut)
 | |
|         MI.RemoveOperand(MI.getNumOperands()-1);
 | |
|       Offset = 0;
 | |
|       return true;
 | |
|     }
 | |
| 
 | |
|     // Otherwise, extract 8 adjacent bits from the immediate into this
 | |
|     // t2ADDri/t2SUBri.
 | |
|     unsigned RotAmt = countLeadingZeros<unsigned>(Offset);
 | |
|     unsigned ThisImmVal = Offset & ARM_AM::rotr32(0xff000000U, RotAmt);
 | |
| 
 | |
|     // We will handle these bits from offset, clear them.
 | |
|     Offset &= ~ThisImmVal;
 | |
| 
 | |
|     assert(ARM_AM::getT2SOImmVal(ThisImmVal) != -1 &&
 | |
|            "Bit extraction didn't work?");
 | |
|     MI.getOperand(FrameRegIdx+1).ChangeToImmediate(ThisImmVal);
 | |
|     // Add cc_out operand if the original instruction did not have one.
 | |
|     if (!HasCCOut)
 | |
|       MI.addOperand(MachineOperand::CreateReg(0, false));
 | |
| 
 | |
|   } else {
 | |
| 
 | |
|     // AddrMode4 and AddrMode6 cannot handle any offset.
 | |
|     if (AddrMode == ARMII::AddrMode4 || AddrMode == ARMII::AddrMode6)
 | |
|       return false;
 | |
| 
 | |
|     // AddrModeT2_so cannot handle any offset. If there is no offset
 | |
|     // register then we change to an immediate version.
 | |
|     unsigned NewOpc = Opcode;
 | |
|     if (AddrMode == ARMII::AddrModeT2_so) {
 | |
|       unsigned OffsetReg = MI.getOperand(FrameRegIdx+1).getReg();
 | |
|       if (OffsetReg != 0) {
 | |
|         MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
 | |
|         return Offset == 0;
 | |
|       }
 | |
| 
 | |
|       MI.RemoveOperand(FrameRegIdx+1);
 | |
|       MI.getOperand(FrameRegIdx+1).ChangeToImmediate(0);
 | |
|       NewOpc = immediateOffsetOpcode(Opcode);
 | |
|       AddrMode = ARMII::AddrModeT2_i12;
 | |
|     }
 | |
| 
 | |
|     unsigned NumBits = 0;
 | |
|     unsigned Scale = 1;
 | |
|     if (AddrMode == ARMII::AddrModeT2_i8 || AddrMode == ARMII::AddrModeT2_i12) {
 | |
|       // i8 supports only negative, and i12 supports only positive, so
 | |
|       // based on Offset sign convert Opcode to the appropriate
 | |
|       // instruction
 | |
|       Offset += MI.getOperand(FrameRegIdx+1).getImm();
 | |
|       if (Offset < 0) {
 | |
|         NewOpc = negativeOffsetOpcode(Opcode);
 | |
|         NumBits = 8;
 | |
|         isSub = true;
 | |
|         Offset = -Offset;
 | |
|       } else {
 | |
|         NewOpc = positiveOffsetOpcode(Opcode);
 | |
|         NumBits = 12;
 | |
|       }
 | |
|     } else if (AddrMode == ARMII::AddrMode5) {
 | |
|       // VFP address mode.
 | |
|       const MachineOperand &OffOp = MI.getOperand(FrameRegIdx+1);
 | |
|       int InstrOffs = ARM_AM::getAM5Offset(OffOp.getImm());
 | |
|       if (ARM_AM::getAM5Op(OffOp.getImm()) == ARM_AM::sub)
 | |
|         InstrOffs *= -1;
 | |
|       NumBits = 8;
 | |
|       Scale = 4;
 | |
|       Offset += InstrOffs * 4;
 | |
|       assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!");
 | |
|       if (Offset < 0) {
 | |
|         Offset = -Offset;
 | |
|         isSub = true;
 | |
|       }
 | |
|     } else if (AddrMode == ARMII::AddrModeT2_i8s4) {
 | |
|       Offset += MI.getOperand(FrameRegIdx + 1).getImm() * 4;
 | |
|       NumBits = 8;
 | |
|       // MCInst operand has already scaled value.
 | |
|       Scale = 1;
 | |
|       if (Offset < 0) {
 | |
|         isSub = true;
 | |
|         Offset = -Offset;
 | |
|       }
 | |
|     } else {
 | |
|       llvm_unreachable("Unsupported addressing mode!");
 | |
|     }
 | |
| 
 | |
|     if (NewOpc != Opcode)
 | |
|       MI.setDesc(TII.get(NewOpc));
 | |
| 
 | |
|     MachineOperand &ImmOp = MI.getOperand(FrameRegIdx+1);
 | |
| 
 | |
|     // Attempt to fold address computation
 | |
|     // Common case: small offset, fits into instruction.
 | |
|     int ImmedOffset = Offset / Scale;
 | |
|     unsigned Mask = (1 << NumBits) - 1;
 | |
|     if ((unsigned)Offset <= Mask * Scale) {
 | |
|       // Replace the FrameIndex with fp/sp
 | |
|       MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
 | |
|       if (isSub) {
 | |
|         if (AddrMode == ARMII::AddrMode5)
 | |
|           // FIXME: Not consistent.
 | |
|           ImmedOffset |= 1 << NumBits;
 | |
|         else
 | |
|           ImmedOffset = -ImmedOffset;
 | |
|       }
 | |
|       ImmOp.ChangeToImmediate(ImmedOffset);
 | |
|       Offset = 0;
 | |
|       return true;
 | |
|     }
 | |
| 
 | |
|     // Otherwise, offset doesn't fit. Pull in what we can to simplify
 | |
|     ImmedOffset = ImmedOffset & Mask;
 | |
|     if (isSub) {
 | |
|       if (AddrMode == ARMII::AddrMode5)
 | |
|         // FIXME: Not consistent.
 | |
|         ImmedOffset |= 1 << NumBits;
 | |
|       else {
 | |
|         ImmedOffset = -ImmedOffset;
 | |
|         if (ImmedOffset == 0)
 | |
|           // Change the opcode back if the encoded offset is zero.
 | |
|           MI.setDesc(TII.get(positiveOffsetOpcode(NewOpc)));
 | |
|       }
 | |
|     }
 | |
|     ImmOp.ChangeToImmediate(ImmedOffset);
 | |
|     Offset &= ~(Mask*Scale);
 | |
|   }
 | |
| 
 | |
|   Offset = (isSub) ? -Offset : Offset;
 | |
|   return Offset == 0;
 | |
| }
 | |
| 
 | |
| ARMCC::CondCodes
 | |
| llvm::getITInstrPredicate(const MachineInstr *MI, unsigned &PredReg) {
 | |
|   unsigned Opc = MI->getOpcode();
 | |
|   if (Opc == ARM::tBcc || Opc == ARM::t2Bcc)
 | |
|     return ARMCC::AL;
 | |
|   return getInstrPredicate(MI, PredReg);
 | |
| }
 |