[llvm-commits] [llvm] r134114 - in /llvm/trunk: lib/Target/ARM/ARMAsmPrinter.cpp lib/Target/ARM/ARMBaseRegisterInfo.cpp lib/Target/ARM/ARMInstrThumb2.td lib/Target/ARM/ARMLoadStoreOptimizer.cpp lib/Target/ARM/Thumb2InstrInfo.cpp lib/Target/ARM/Thumb2SizeReduction.cpp utils/TableGen/ARMDecoderEmitter.cpp

Evan Cheng evan.cheng at apple.com
Wed Jun 29 18:49:34 PDT 2011


Thumb2InstrInfo.cpp:422:10: warning: unused variable 'isSP' [-Wunused-variable]
    bool isSP = FrameReg == ARM::SP;
         ^

On Jun 29, 2011, at 4:25 PM, Jim Grosbach wrote:

> Author: grosbach
> Date: Wed Jun 29 18:25:04 2011
> New Revision: 134114
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=134114&view=rev
> Log:
> Remove redundant Thumb2 ADD/SUB SP instruction definitions.
> 
> Unlike Thumb1, Thumb2 does not have dedicated encodings for adjusting the
> stack pointer. It can just use the normal add-register-immediate encoding
> since it can use all registers as a source, not just R0-R7. The extra
> instruction definitions are just duplicates of the normal instructions with
> the (not well enforced) constraint that the source register was SP.
> 
> 
> Modified:
>    llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp
>    llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp
>    llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td
>    llvm/trunk/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
>    llvm/trunk/lib/Target/ARM/Thumb2InstrInfo.cpp
>    llvm/trunk/lib/Target/ARM/Thumb2SizeReduction.cpp
>    llvm/trunk/utils/TableGen/ARMDecoderEmitter.cpp
> 
> Modified: llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp?rev=134114&r1=134113&r2=134114&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp (original)
> +++ llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp Wed Jun 29 18:25:04 2011
> @@ -1018,11 +1018,10 @@
>         Offset = -MI->getOperand(2).getImm();
>         break;
>       case ARM::SUBri:
> -      case ARM::t2SUBrSPi:
> -        Offset =  MI->getOperand(2).getImm();
> +        Offset = MI->getOperand(2).getImm();
>         break;
>       case ARM::tSUBspi:
> -        Offset =  MI->getOperand(2).getImm()*4;
> +        Offset = MI->getOperand(2).getImm()*4;
>         break;
>       case ARM::tADDspi:
>       case ARM::tADDrSPi:
> @@ -1097,13 +1096,6 @@
>     OutStreamer.EmitInstruction(TmpInst);
>     return;
>   }
> -  case ARM::t2ADDrSPi:
> -  case ARM::t2ADDrSPi12:
> -  case ARM::t2SUBrSPi:
> -  case ARM::t2SUBrSPi12:
> -    assert ((MI->getOperand(1).getReg() == ARM::SP) &&
> -            "Unexpected source register!");
> -    break;
> 
>   case ARM::t2MOVi32imm: assert(0 && "Should be lowered by thumb2it pass");
>   case ARM::DBG_VALUE: {
> 
> Modified: llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp?rev=134114&r1=134113&r2=134114&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp (original)
> +++ llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp Wed Jun 29 18:25:04 2011
> @@ -1284,9 +1284,5 @@
>     }
>     // Update the original instruction to use the scratch register.
>     MI.getOperand(i).ChangeToRegister(ScratchReg, false, false, true);
> -    if (MI.getOpcode() == ARM::t2ADDrSPi)
> -      MI.setDesc(TII.get(ARM::t2ADDri));
> -    else if (MI.getOpcode() == ARM::t2SUBrSPi)
> -      MI.setDesc(TII.get(ARM::t2SUBri));
>   }
> }
> 
> Modified: llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td?rev=134114&r1=134113&r2=134114&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td (original)
> +++ llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td Wed Jun 29 18:25:04 2011
> @@ -1169,63 +1169,6 @@
>                                 []>;
> 
> 
> -// FIXME: None of these add/sub SP special instructions should be necessary
> -// at all for thumb2 since they use the same encodings as the generic
> -// add/sub instructions. In thumb1 we need them since they have dedicated
> -// encodings. At the least, they should be pseudo instructions.
> -// ADD r, sp, {so_imm|i12}
> -let isCodeGenOnly = 1 in {
> -def t2ADDrSPi   : T2sTwoRegImm<(outs GPR:$Rd), (ins GPR:$Rn, t2_so_imm:$imm),
> -                        IIC_iALUi, "add", ".w\t$Rd, $Rn, $imm", []> {
> -  let Inst{31-27} = 0b11110;
> -  let Inst{25} = 0;
> -  let Inst{24-21} = 0b1000;
> -  let Inst{15} = 0;
> -}
> -def t2ADDrSPi12 : T2TwoRegImm<(outs GPR:$Rd), (ins GPR:$Rn, imm0_4095:$imm),
> -                       IIC_iALUi, "addw", "\t$Rd, $Rn, $imm", []> {
> -  let Inst{31-27} = 0b11110;
> -  let Inst{25-20} = 0b100000;
> -  let Inst{15} = 0;
> -}
> -
> -// ADD r, sp, so_reg
> -def t2ADDrSPs   : T2sTwoRegShiftedReg<
> -                        (outs GPR:$Rd), (ins GPR:$Rn, t2_so_reg:$ShiftedRm),
> -                        IIC_iALUsi, "add", ".w\t$Rd, $Rn, $ShiftedRm", []> {
> -  let Inst{31-27} = 0b11101;
> -  let Inst{26-25} = 0b01;
> -  let Inst{24-21} = 0b1000;
> -  let Inst{15} = 0;
> -}
> -
> -// SUB r, sp, {so_imm|i12}
> -def t2SUBrSPi   : T2sTwoRegImm<(outs GPR:$Rd), (ins GPR:$Rn, t2_so_imm:$imm),
> -                        IIC_iALUi, "sub", ".w\t$Rd, $Rn, $imm", []> {
> -  let Inst{31-27} = 0b11110;
> -  let Inst{25} = 0;
> -  let Inst{24-21} = 0b1101;
> -  let Inst{15} = 0;
> -}
> -def t2SUBrSPi12 : T2TwoRegImm<(outs GPR:$Rd), (ins GPR:$Rn, imm0_4095:$imm),
> -                       IIC_iALUi, "subw", "\t$Rd, $Rn, $imm", []> {
> -  let Inst{31-27} = 0b11110;
> -  let Inst{25-20} = 0b101010;
> -  let Inst{15} = 0;
> -}
> -
> -// SUB r, sp, so_reg
> -def t2SUBrSPs   : T2sTwoRegImm<(outs GPR:$Rd), (ins GPR:$Rn, t2_so_reg:$imm),
> -                       IIC_iALUsi,
> -                       "sub", "\t$Rd, $Rn, $imm", []> {
> -  let Inst{31-27} = 0b11101;
> -  let Inst{26-25} = 0b01;
> -  let Inst{24-21} = 0b1101;
> -  let Inst{19-16} = 0b1101; // Rn = sp
> -  let Inst{15} = 0;
> -}
> -} // end isCodeGenOnly = 1
> -
> //===----------------------------------------------------------------------===//
> //  Load / store Instructions.
> //
> 
> Modified: llvm/trunk/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMLoadStoreOptimizer.cpp?rev=134114&r1=134113&r2=134114&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/ARM/ARMLoadStoreOptimizer.cpp (original)
> +++ llvm/trunk/lib/Target/ARM/ARMLoadStoreOptimizer.cpp Wed Jun 29 18:25:04 2011
> @@ -329,13 +329,9 @@
>       if (NewBase == 0)
>         return false;
>     }
> -    int BaseOpc = !isThumb2
> -      ? ARM::ADDri
> -      : ((Base == ARM::SP) ? ARM::t2ADDrSPi : ARM::t2ADDri);
> +    int BaseOpc = !isThumb2 ? ARM::ADDri : ARM::t2ADDri;
>     if (Offset < 0) {
> -      BaseOpc = !isThumb2
> -        ? ARM::SUBri
> -        : ((Base == ARM::SP) ? ARM::t2SUBrSPi : ARM::t2SUBri);
> +      BaseOpc = !isThumb2 ? ARM::SUBri : ARM::t2SUBri;
>       Offset = - Offset;
>     }
>     int ImmedOffset = isThumb2
> @@ -516,8 +512,6 @@
>   if (!MI)
>     return false;
>   if (MI->getOpcode() != ARM::t2SUBri &&
> -      MI->getOpcode() != ARM::t2SUBrSPi &&
> -      MI->getOpcode() != ARM::t2SUBrSPi12 &&
>       MI->getOpcode() != ARM::tSUBspi &&
>       MI->getOpcode() != ARM::SUBri)
>     return false;
> @@ -541,8 +535,6 @@
>   if (!MI)
>     return false;
>   if (MI->getOpcode() != ARM::t2ADDri &&
> -      MI->getOpcode() != ARM::t2ADDrSPi &&
> -      MI->getOpcode() != ARM::t2ADDrSPi12 &&
>       MI->getOpcode() != ARM::tADDspi &&
>       MI->getOpcode() != ARM::ADDri)
>     return false;
> 
> Modified: llvm/trunk/lib/Target/ARM/Thumb2InstrInfo.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/Thumb2InstrInfo.cpp?rev=134114&r1=134113&r2=134114&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/ARM/Thumb2InstrInfo.cpp (original)
> +++ llvm/trunk/lib/Target/ARM/Thumb2InstrInfo.cpp Wed Jun 29 18:25:04 2011
> @@ -251,7 +251,7 @@
>       }
> 
>       // sub rd, sp, so_imm
> -      Opc = isSub ? ARM::t2SUBrSPi : ARM::t2ADDrSPi;
> +      Opc = isSub ? ARM::t2SUBri : ARM::t2ADDri;
>       if (ARM_AM::getT2SOImmVal(NumBytes) != -1) {
>         NumBytes = 0;
>       } else {
> @@ -425,9 +425,9 @@
>     if (Offset < 0) {
>       Offset = -Offset;
>       isSub = true;
> -      MI.setDesc(TII.get(isSP ? ARM::t2SUBrSPi : ARM::t2SUBri));
> +      MI.setDesc(TII.get(ARM::t2SUBri));
>     } else {
> -      MI.setDesc(TII.get(isSP ? ARM::t2ADDrSPi : ARM::t2ADDri));
> +      MI.setDesc(TII.get(ARM::t2ADDri));
>     }
> 
>     // Common case: small offset, fits into instruction.
> @@ -443,9 +443,7 @@
>     // Another common case: imm12.
>     if (Offset < 4096 &&
>         (!HasCCOut || MI.getOperand(MI.getNumOperands()-1).getReg() == 0)) {
> -      unsigned NewOpc = isSP
> -        ? (isSub ? ARM::t2SUBrSPi12 : ARM::t2ADDrSPi12)
> -        : (isSub ? ARM::t2SUBri12   : ARM::t2ADDri12);
> +      unsigned NewOpc = isSub ? ARM::t2SUBri12 : ARM::t2ADDri12;
>       MI.setDesc(TII.get(NewOpc));
>       MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
>       MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset);
> 
> Modified: llvm/trunk/lib/Target/ARM/Thumb2SizeReduction.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/Thumb2SizeReduction.cpp?rev=134114&r1=134113&r2=134114&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/ARM/Thumb2SizeReduction.cpp (original)
> +++ llvm/trunk/lib/Target/ARM/Thumb2SizeReduction.cpp Wed Jun 29 18:25:04 2011
> @@ -57,10 +57,8 @@
>   static const ReduceEntry ReduceTable[] = {
>     // Wide,        Narrow1,      Narrow2,     imm1,imm2,  lo1, lo2, P/C, PF, S
>     { ARM::t2ADCrr, 0,            ARM::tADC,     0,   0,    0,   1,  0,0, 0,0 },
> -    { ARM::t2ADDri, ARM::tADDi3,  ARM::tADDi8,   3,   8,    1,   1,  0,0, 0,0 },
> +    { ARM::t2ADDri, ARM::tADDi3,  ARM::tADDi8,   3,   8,    1,   1,  0,0, 0,1 },
>     { ARM::t2ADDrr, ARM::tADDrr,  ARM::tADDhirr, 0,   0,    1,   0,  0,1, 0,0 },
> -    // Note: immediate scale is 4.
> -    { ARM::t2ADDrSPi,ARM::tADDrSPi,0,            8,   0,    1,   0,  1,0, 0,1 },
>     { ARM::t2ADDSri,ARM::tADDi3,  ARM::tADDi8,   3,   8,    1,   1,  2,2, 0,1 },
>     { ARM::t2ADDSrr,ARM::tADDrr,  0,             0,   0,    1,   0,  2,0, 0,1 },
>     { ARM::t2ANDrr, 0,            ARM::tAND,     0,   0,    0,   1,  0,0, 1,0 },
> @@ -291,7 +289,7 @@
>                  Opc == ARM::t2LDMDB     || Opc == ARM::t2LDMIA_UPD ||
>                  Opc == ARM::t2LDMDB_UPD);
>   bool isLROk = (Opc == ARM::t2STMIA_UPD || Opc == ARM::t2STMDB_UPD);
> -  bool isSPOk = isPCOk || isLROk || (Opc == ARM::t2ADDrSPi);
> +  bool isSPOk = isPCOk || isLROk;
>   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
>     const MachineOperand &MO = MI->getOperand(i);
>     if (!MO.isReg() || MO.isImplicit())
> @@ -481,6 +479,44 @@
> Thumb2SizeReduce::ReduceSpecial(MachineBasicBlock &MBB, MachineInstr *MI,
>                                 const ReduceEntry &Entry,
>                                 bool LiveCPSR, MachineInstr *CPSRDef) {
> +  unsigned Opc = MI->getOpcode();
> +  if (Opc == ARM::t2ADDri) {
> +    // If the source register is SP, try to reduce to tADDrSPi, otherwise
> +    // it's a normal reduce.
> +    if (MI->getOperand(1).getReg() != ARM::SP) {
> +      if (ReduceTo2Addr(MBB, MI, Entry, LiveCPSR, CPSRDef))
> +        return true;
> +      return ReduceToNarrow(MBB, MI, Entry, LiveCPSR, CPSRDef);
> +    }
> +    // Try to reduce to tADDrSPi.
> +    unsigned Imm = MI->getOperand(2).getImm();
> +    // The immediate must be in range, the destination register must be a low
> +    // reg, and the condition flags must not be being set.
> +    if (Imm & 3 || Imm > 1024)
> +      return false;
> +    if (!isARMLowRegister(MI->getOperand(0).getReg()))
> +      return false;
> +    const MCInstrDesc &MCID = MI->getDesc();
> +    if (MCID.hasOptionalDef() &&
> +        MI->getOperand(MCID.getNumOperands()-1).getReg() == ARM::CPSR)
> +      return false;
> +
> +    MachineInstrBuilder MIB = BuildMI(MBB, *MI, MI->getDebugLoc(),
> +                                      TII->get(ARM::tADDrSPi))
> +      .addOperand(MI->getOperand(0))
> +      .addOperand(MI->getOperand(1))
> +      .addImm(Imm / 4); // The tADDrSPi has an implied scale by four.
> +
> +    // Transfer MI flags.
> +    MIB.setMIFlags(MI->getFlags());
> +
> +    DEBUG(errs() << "Converted 32-bit: " << *MI << "       to 16-bit: " <<*MIB);
> +
> +    MBB.erase(MI);
> +    ++NumNarrows;
> +    return true;
> +  }
> +
>   if (Entry.LowRegs1 && !VerifyLowRegs(MI))
>     return false;
> 
> @@ -488,7 +524,6 @@
>   if (MCID.mayLoad() || MCID.mayStore())
>     return ReduceLoadStore(MBB, MI, Entry);
> 
> -  unsigned Opc = MI->getOpcode();
>   switch (Opc) {
>   default: break;
>   case ARM::t2ADDSri:
> @@ -531,13 +566,6 @@
>       return true;
>     return ReduceToNarrow(MBB, MI, Entry, LiveCPSR, CPSRDef);
>   }
> -  case ARM::t2ADDrSPi: {
> -    static const ReduceEntry NarrowEntry =
> -      { ARM::t2ADDrSPi,ARM::tADDspi, 0, 7, 0, 1, 0, 1, 0, 0,1 };
> -    if (MI->getOperand(0).getReg() == ARM::SP)
> -      return ReduceToNarrow(MBB, MI, NarrowEntry, LiveCPSR, CPSRDef);
> -    return ReduceToNarrow(MBB, MI, Entry, LiveCPSR, CPSRDef);
> -  }
>   }
>   return false;
> }
> @@ -645,9 +673,8 @@
>     return false;
> 
>   unsigned Limit = ~0U;
> -  unsigned Scale = (Entry.WideOpc == ARM::t2ADDrSPi) ? 4 : 1;
>   if (Entry.Imm1Limit)
> -    Limit = ((1 << Entry.Imm1Limit) - 1) * Scale;
> +    Limit = (1 << Entry.Imm1Limit) - 1;
> 
>   const MCInstrDesc &MCID = MI->getDesc();
>   for (unsigned i = 0, e = MCID.getNumOperands(); i != e; ++i) {
> @@ -658,13 +685,11 @@
>       unsigned Reg = MO.getReg();
>       if (!Reg || Reg == ARM::CPSR)
>         continue;
> -      if (Entry.WideOpc == ARM::t2ADDrSPi && Reg == ARM::SP)
> -        continue;
>       if (Entry.LowRegs1 && !isARMLowRegister(Reg))
>         return false;
>     } else if (MO.isImm() &&
>                !MCID.OpInfo[i].isPredicate()) {
> -      if (((unsigned)MO.getImm()) > Limit || (MO.getImm() & (Scale-1)) != 0)
> +      if (((unsigned)MO.getImm()) > Limit)
>         return false;
>     }
>   }
> @@ -723,15 +748,11 @@
>     if (SkipPred && isPred)
>         continue;
>     const MachineOperand &MO = MI->getOperand(i);
> -    if (Scale > 1 && !isPred && MO.isImm())
> -      MIB.addImm(MO.getImm() / Scale);
> -    else {
> -      if (MO.isReg() && MO.isImplicit() && MO.getReg() == ARM::CPSR)
> -        // Skip implicit def of CPSR. Either it's modeled as an optional
> -        // def now or it's already an implicit def on the new instruction.
> -        continue;
> -      MIB.addOperand(MO);
> -    }
> +    if (MO.isReg() && MO.isImplicit() && MO.getReg() == ARM::CPSR)
> +      // Skip implicit def of CPSR. Either it's modeled as an optional
> +      // def now or it's already an implicit def on the new instruction.
> +      continue;
> +    MIB.addOperand(MO);
>   }
>   if (!MCID.isPredicable() && NewMCID.isPredicable())
>     AddDefaultPred(MIB);
> 
> Modified: llvm/trunk/utils/TableGen/ARMDecoderEmitter.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/ARMDecoderEmitter.cpp?rev=134114&r1=134113&r2=134114&view=diff
> ==============================================================================
> --- llvm/trunk/utils/TableGen/ARMDecoderEmitter.cpp (original)
> +++ llvm/trunk/utils/TableGen/ARMDecoderEmitter.cpp Wed Jun 29 18:25:04 2011
> @@ -1640,12 +1640,8 @@
>     // Ignore tADDrSP, tADDspr, and tPICADD, prefer the generic tADDhirr.
>     // Ignore t2SUBrSPs, prefer the t2SUB[S]r[r|s].
>     // Ignore t2ADDrSPs, prefer the t2ADD[S]r[r|s].
> -    // Ignore t2ADDrSPi/t2SUBrSPi, which have more generic couterparts.
> -    // Ignore t2ADDrSPi12/t2SUBrSPi12, which have more generic couterparts
>     if (Name == "tADDrSP" || Name == "tADDspr" || Name == "tPICADD" ||
> -        Name == "t2SUBrSPs" || Name == "t2ADDrSPs" ||
> -        Name == "t2ADDrSPi" || Name == "t2SUBrSPi" ||
> -        Name == "t2ADDrSPi12" || Name == "t2SUBrSPi12")
> +        Name == "t2SUBrSPs" || Name == "t2ADDrSPs")
>       return false;
> 
>     // FIXME: Use ldr.n to work around a Darwin assembler bug.
> 
> 
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits




More information about the llvm-commits mailing list