Refactor away tSpill and tRestore pseudos in ARM backend.

The tSpill and tRestore instructions are just copies of the tSTRspi and
tLDRspi instructions, respectively. Just use those directly instead.

llvm-svn: 134092

llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp

@@ -792,7 +792,7 @@ ARMBaseInstrInfo::isStoreToStackSlot(const MachineInstr *MI,
     break;
   case ARM::STRi12:
   case ARM::t2STRi12:
-  case ARM::tSpill:
+  case ARM::tSTRspi:
   case ARM::VSTRD:
   case ARM::VSTRS:
     if (MI->getOperand(1).isFI() &&
@@ -927,7 +927,7 @@ ARMBaseInstrInfo::isLoadFromStackSlot(const MachineInstr *MI,
     break;
   case ARM::LDRi12:
   case ARM::t2LDRi12:
-  case ARM::tRestore:
+  case ARM::tLDRspi:
   case ARM::VLDRD:
   case ARM::VLDRS:
     if (MI->getOperand(1).isFI() &&

llvm/lib/Target/ARM/ARMInstrThumb.td

@@ -686,19 +686,6 @@ def tLDRspi : T1pIs<(outs tGPR:$Rt), (ins t_addrmode_sp:$addr), IIC_iLoad_i,
   let Inst{7-0} = addr;
 }
 
-// Special instruction for restore. It cannot clobber condition register
-// when it's expanded by eliminateCallFramePseudoInstr().
-let canFoldAsLoad = 1, mayLoad = 1, neverHasSideEffects = 1 in
-// FIXME: Pseudo for tLDRspi
-def tRestore : T1pIs<(outs tGPR:$dst), (ins t_addrmode_sp:$addr), IIC_iLoad_i,
-                     "ldr", "\t$dst, $addr", []>,
-               T1LdStSP<{1,?,?}> {
-  bits<3> Rt;
-  bits<8> addr;
-  let Inst{10-8} = Rt;
-  let Inst{7-0} = addr;
-}
-
 // Load tconstpool
 // FIXME: Use ldr.n to work around a Darwin assembler bug.
 let canFoldAsLoad = 1, isReMaterializable = 1 in
@@ -755,19 +742,6 @@ def tSTRspi : T1pIs<(outs), (ins tGPR:$Rt, t_addrmode_sp:$addr), IIC_iStore_i,
   let Inst{7-0} = addr;
 }
 
-let mayStore = 1, neverHasSideEffects = 1 in
-// Special instruction for spill. It cannot clobber condition register when it's
-// expanded by eliminateCallFramePseudoInstr().
-// FIXME: Pseudo for tSTRspi
-def tSpill : T1pIs<(outs), (ins tGPR:$src, t_addrmode_sp:$addr), IIC_iStore_i,
-                  "str", "\t$src, $addr", []>,
-             T1LdStSP<{0,?,?}> {
-  bits<3> Rt;
-  bits<8> addr;
-  let Inst{10-8} = Rt;
-  let Inst{7-0} = addr;
-}
-
 //===----------------------------------------------------------------------===//
 //  Load / store multiple Instructions.
 //

llvm/lib/Target/ARM/Thumb1FrameLowering.cpp

@@ -177,7 +177,7 @@ static bool isCalleeSavedRegister(unsigned Reg, const unsigned *CSRegs) {
 }
 
 static bool isCSRestore(MachineInstr *MI, const unsigned *CSRegs) {
-  if (MI->getOpcode() == ARM::tRestore &&
+  if (MI->getOpcode() == ARM::tLDRspi &&
       MI->getOperand(1).isFI() &&
       isCalleeSavedRegister(MI->getOperand(0).getReg(), CSRegs))
     return true;

llvm/lib/Target/ARM/Thumb1InstrInfo.cpp

@@ -75,7 +75,7 @@ storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
                               MachineMemOperand::MOStore,
                               MFI.getObjectSize(FI),
                               MFI.getObjectAlignment(FI));
-    AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::tSpill))
+    AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::tSTRspi))
                    .addReg(SrcReg, getKillRegState(isKill))
                    .addFrameIndex(FI).addImm(0).addMemOperand(MMO));
   }
@@ -104,7 +104,7 @@ loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
                               MachineMemOperand::MOLoad,
                               MFI.getObjectSize(FI),
                               MFI.getObjectAlignment(FI));
-    AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::tRestore), DestReg)
+    AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::tLDRspi), DestReg)
                    .addFrameIndex(FI).addImm(0).addMemOperand(MMO));
   }
 }

llvm/lib/Target/ARM/Thumb1RegisterInfo.cpp

@@ -377,11 +377,9 @@ static void removeOperands(MachineInstr &MI, unsigned i) {
 static unsigned convertToNonSPOpcode(unsigned Opcode) {
   switch (Opcode) {
   case ARM::tLDRspi:
-  case ARM::tRestore:           // FIXME: Should this opcode be here?
     return ARM::tLDRi;
 
   case ARM::tSTRspi:
-  case ARM::tSpill:             // FIXME: Should this opcode be here?
     return ARM::tSTRi;
   }
 
@@ -524,7 +522,7 @@ rewriteFrameIndex(MachineBasicBlock::iterator II, unsigned FrameRegIdx,
 
     // If this is a thumb spill / restore, we will be using a constpool load to
     // materialize the offset.
-    if (Opcode == ARM::tRestore || Opcode == ARM::tSpill) {
+    if (Opcode == ARM::tLDRspi || Opcode == ARM::tSTRspi) {
       ImmOp.ChangeToImmediate(0);
     } else {
       // Otherwise, it didn't fit. Pull in what we can to simplify the immed.
@@ -664,7 +662,7 @@ Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
     // Use the destination register to materialize sp + offset.
     unsigned TmpReg = MI.getOperand(0).getReg();
     bool UseRR = false;
-    if (Opcode == ARM::tRestore) {
+    if (Opcode == ARM::tLDRspi) {
       if (FrameReg == ARM::SP)
         emitThumbRegPlusImmInReg(MBB, II, dl, TmpReg, FrameReg,
                                  Offset, false, TII, *this);
@@ -687,7 +685,7 @@ Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
       VReg = MF.getRegInfo().createVirtualRegister(ARM::tGPRRegisterClass);
       bool UseRR = false;
 
-      if (Opcode == ARM::tSpill) {
+      if (Opcode == ARM::tSTRspi) {
         if (FrameReg == ARM::SP)
           emitThumbRegPlusImmInReg(MBB, II, dl, VReg, FrameReg,
                                    Offset, false, TII, *this);

llvm/utils/TableGen/ARMDecoderEmitter.cpp

@@ -1667,14 +1667,12 @@ ARMDEBackend::populateInstruction(const CodeGenInstruction &CGI,
     //   tPOP_RET/t2LDMIA_RET conflict with tPOP/t2LDM (ditto)
     //   tMOVCCi conflicts with tMOVi8
     //   tMOVCCr conflicts with tMOVgpr2gpr
-    //   tSpill conflicts with tSTRspi
     //   tLDRcp conflicts with tLDRspi
-    //   tRestore conflicts with tLDRspi
     //   t2MOVCCi16 conflicts with tMOVi16
     if (Name == "tBfar" ||
         Name == "tPOP_RET" || Name == "t2LDMIA_RET" ||
         Name == "tMOVCCi" || Name == "tMOVCCr" ||
-        Name == "tSpill" || Name == "tLDRcp" || Name == "tRestore" ||
+        Name == "tLDRcp" || 
         Name == "t2MOVCCi16")
       return false;
   }