Revert both r121082 (which broke a bunch of constant pool stuff) and r125074 (which worked around it). This should get us back to the old, correct behavior, though it will make the integrated assembler unhappy for the time being.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125127 91177308-0d34-0410-b5e6-96231b3b80d8

8 files changed, 86 insertions, 128 deletions

diff --git a/lib/Target/ARM/ARMConstantIslandPass.cpp b/lib/Target/ARM/ARMConstantIslandPass.cpp
index f8f717e4d4..934daba552 100644
--- a/lib/Target/ARM/ARMConstantIslandPass.cpp
+++ b/lib/Target/ARM/ARMConstantIslandPass.cpp
@@ -613,11 +613,7 @@ void ARMConstantIslands::InitialFunctionScan(MachineFunction &MF,
 
           case ARM::LDRi12:
           case ARM::LDRcp:
-          case ARM::t2LDRi12:
-          case ARM::t2LDRHi12:
-          case ARM::t2LDRBi12:
-          case ARM::t2LDRSHi12:
-          case ARM::t2LDRSBi12:
+          case ARM::t2LDRpci:
             Bits = 12;  // +-offset_12
             NegOk = true;
             break;
@@ -1576,16 +1572,6 @@ bool ARMConstantIslands::OptimizeThumb2Instructions(MachineFunction &MF) {
         Scale = 4;
       }
       break;
-    case ARM::t2LDRi12:
-      // FIXME: Temporary workaround for a  bug introduced by r121082.
-      // We should use t2LDRpci for loads from constantpools.
-      if (isARMLowRegister(U.MI->getOperand(0).getReg()) &&
-          U.MI->getOperand(1).getReg() == ARM::PC) {
-        NewOpc = ARM::tLDRpci;
-        Bits = 8;
-        Scale = 4;
-      }
-      break;
     }
 
     if (!NewOpc)
@@ -1596,10 +1582,6 @@ bool ARMConstantIslands::OptimizeThumb2Instructions(MachineFunction &MF) {
     // FIXME: Check if offset is multiple of scale if scale is not 4.
     if (CPEIsInRange(U.MI, UserOffset, U.CPEMI, MaxOffs, false, true)) {
       U.MI->setDesc(TII->get(NewOpc));
-      if (NewOpc == ARM::tLDRpci)
-        // FIXME: Temporary workaround.
-        // PC is now an implicit operand.
-        U.MI->RemoveOperand(1);
       MachineBasicBlock *MBB = U.MI->getParent();
       BBSizes[MBB->getNumber()] -= 2;
       AdjustBBOffsetsAfter(MBB, -2);
diff --git a/lib/Target/ARM/ARMExpandPseudoInsts.cpp b/lib/Target/ARM/ARMExpandPseudoInsts.cpp
index e0aeb920af..bd753d29ab 100644
--- a/lib/Target/ARM/ARMExpandPseudoInsts.cpp
+++ b/lib/Target/ARM/ARMExpandPseudoInsts.cpp
@@ -780,7 +780,7 @@ bool ARMExpandPseudo::ExpandMI(MachineBasicBlock &MBB,
       return true;
     }
     case ARM::TPsoft: {
-      MachineInstrBuilder MIB = 
+      MachineInstrBuilder MIB =
         BuildMI(MBB, MBBI, MI.getDebugLoc(),
                 TII->get(ARM::BL))
         .addExternalSymbol("__aeabi_read_tp", 0);
@@ -790,49 +790,16 @@ bool ARMExpandPseudo::ExpandMI(MachineBasicBlock &MBB,
       MI.eraseFromParent();
       return true;
     }
-    case ARM::t2LDRHpci:
-    case ARM::t2LDRBpci:
-    case ARM::t2LDRSHpci:
-    case ARM::t2LDRSBpci:
-    case ARM::t2LDRpci: {
-      unsigned NewLdOpc;
-      if (Opcode == ARM::t2LDRpci)
-        NewLdOpc = ARM::t2LDRi12;
-      else if (Opcode == ARM::t2LDRHpci)
-        NewLdOpc = ARM::t2LDRHi12;
-      else if (Opcode == ARM::t2LDRBpci)
-        NewLdOpc = ARM::t2LDRBi12;
-      else if (Opcode == ARM::t2LDRSHpci)
-        NewLdOpc = ARM::t2LDRSHi12;
-      else if (Opcode == ARM::t2LDRSBpci)
-        NewLdOpc = ARM::t2LDRSBi12;
-      else
-        llvm_unreachable("Not a known opcode?");
-
-      unsigned DstReg = MI.getOperand(0).getReg();
-      MachineInstrBuilder MIB =
-        AddDefaultPred(BuildMI(MBB, MBBI, MI.getDebugLoc(),
-                               TII->get(NewLdOpc), DstReg)
-                       .addReg(ARM::PC)
-                       .addOperand(MI.getOperand(1)));
-      (*MIB).setMemRefs(MI.memoperands_begin(), MI.memoperands_end());
-      TransferImpOps(MI, MIB, MIB);
-      MI.eraseFromParent();
-      return true;
-    }
-
     case ARM::tLDRpci_pic:
     case ARM::t2LDRpci_pic: {
       unsigned NewLdOpc = (Opcode == ARM::tLDRpci_pic)
-        ? ARM::tLDRpci : ARM::t2LDRi12;
+        ? ARM::tLDRpci : ARM::t2LDRpci;
       unsigned DstReg = MI.getOperand(0).getReg();
       bool DstIsDead = MI.getOperand(0).isDead();
       MachineInstrBuilder MIB1 =
-        BuildMI(MBB, MBBI, MI.getDebugLoc(),
-                TII->get(NewLdOpc), DstReg);
-      if (Opcode == ARM::t2LDRpci_pic) MIB1.addReg(ARM::PC);
-      MIB1.addOperand(MI.getOperand(1));
-      AddDefaultPred(MIB1);
+        AddDefaultPred(BuildMI(MBB, MBBI, MI.getDebugLoc(),
+                               TII->get(NewLdOpc), DstReg)
+                       .addOperand(MI.getOperand(1)));
       (*MIB1).setMemRefs(MI.memoperands_begin(), MI.memoperands_end());
       MachineInstrBuilder MIB2 = BuildMI(MBB, MBBI, MI.getDebugLoc(),
                                          TII->get(ARM::tPICADD))
diff --git a/lib/Target/ARM/ARMInstrThumb2.td b/lib/Target/ARM/ARMInstrThumb2.td
index 60b6b1b331..c61c88f8cf 100644
--- a/lib/Target/ARM/ARMInstrThumb2.td
+++ b/lib/Target/ARM/ARMInstrThumb2.td
@@ -910,8 +910,23 @@ multiclass T2I_ld<bit signed, bits<2> opcod, string opc,
     let Inst{5-4}   = addr{1-0}; // imm
   }
 
-  def pci : t2PseudoInst<(outs GPR:$Rt), (ins i32imm:$addr), Size4Bytes, iis,
-                      [(set GPR:$Rt, (opnode (ARMWrapper tconstpool:$addr)))]>;
+  // FIXME: Is the pci variant actually needed?
+  def pci : T2Ipc <(outs GPR:$Rt), (ins i32imm:$addr), iii,
+                   opc, ".w\t$Rt, $addr",
+                   [(set GPR:$Rt, (opnode (ARMWrapper tconstpool:$addr)))]> {
+    let isReMaterializable = 1;
+    let Inst{31-27} = 0b11111;
+    let Inst{26-25} = 0b00;
+    let Inst{24} = signed;
+    let Inst{23} = ?; // add = (U == '1')
+    let Inst{22-21} = opcod;
+    let Inst{20} = 1; // load
+    let Inst{19-16} = 0b1111; // Rn
+    bits<4> Rt;
+    bits<12> addr;
+    let Inst{15-12} = Rt{3-0};
+    let Inst{11-0}  = addr{11-0};
+  }
 }
 
 /// T2I_st - Defines a set of (op r, {imm12|imm8|so_reg}) store patterns.
diff --git a/lib/Target/ARM/ARMMCCodeEmitter.cpp b/lib/Target/ARM/ARMMCCodeEmitter.cpp
index 94321ad57a..6d7b48587d 100644
--- a/lib/Target/ARM/ARMMCCodeEmitter.cpp
+++ b/lib/Target/ARM/ARMMCCodeEmitter.cpp
@@ -58,7 +58,7 @@ public:
                              SmallVectorImpl<MCFixup> &Fixups) const;
 
   /// getHiLo16ImmOpValue - Return the encoding for the hi / low 16-bit of
-  /// the specified operand. This is used for operands with :lower16: and 
+  /// the specified operand. This is used for operands with :lower16: and
   /// :upper16: prefixes.
   uint32_t getHiLo16ImmOpValue(const MCInst &MI, unsigned OpIdx,
                                SmallVectorImpl<MCFixup> &Fixups) const;
@@ -112,7 +112,7 @@ public:
                               SmallVectorImpl<MCFixup> &Fixups) const;
   uint32_t getT2AdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
                               SmallVectorImpl<MCFixup> &Fixups) const;
-  
+
 
   /// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12'
   /// operand.
@@ -536,12 +536,12 @@ getUnconditionalBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
     Val &= ~0x400000;
   else
     Val |= 0x400000;
-    
+
   if (I ^ J2)
     Val &= ~0x200000;
   else
     Val |= 0x200000;
-  
+
   return Val;
 }
 
@@ -601,17 +601,13 @@ getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
   bool isAdd = true;
   // If The first operand isn't a register, we have a label reference.
   const MCOperand &MO = MI.getOperand(OpIdx);
-  const MCOperand &MO2 = MI.getOperand(OpIdx+1);
-  if (!MO.isReg() || (MO.getReg() == ARM::PC && MO2.isExpr())) {
+  if (!MO.isReg()) {
     Reg = getARMRegisterNumbering(ARM::PC);   // Rn is PC.
     Imm12 = 0;
     isAdd = false ; // 'U' bit is set as part of the fixup.
 
-    const MCExpr *Expr = 0;
-    if (!MO.isReg())
-      Expr = MO.getExpr();
-    else
-      Expr = MO2.getExpr();
+    assert(MO.isExpr() && "Unexpected machine operand type!");
+    const MCExpr *Expr = MO.getExpr();
 
     MCFixupKind Kind;
     if (Subtarget->isThumb2())
@@ -699,7 +695,7 @@ ARMMCCodeEmitter::getHiLo16ImmOpValue(const MCInst &MI, unsigned OpIdx,
     switch (ARM16Expr->getKind()) {
     default: assert(0 && "Unsupported ARMFixup");
     case ARMMCExpr::VK_ARM_HI16:
-      if (!Subtarget->isTargetDarwin() && EvaluateAsPCRel(E)) 
+      if (!Subtarget->isTargetDarwin() && EvaluateAsPCRel(E))
         Kind = MCFixupKind(Subtarget->isThumb2()
                            ? ARM::fixup_t2_movt_hi16_pcrel
                            : ARM::fixup_arm_movt_hi16_pcrel);
@@ -709,7 +705,7 @@ ARMMCCodeEmitter::getHiLo16ImmOpValue(const MCInst &MI, unsigned OpIdx,
                            : ARM::fixup_arm_movt_hi16);
       break;
     case ARMMCExpr::VK_ARM_LO16:
-      if (!Subtarget->isTargetDarwin() && EvaluateAsPCRel(E)) 
+      if (!Subtarget->isTargetDarwin() && EvaluateAsPCRel(E))
         Kind = MCFixupKind(Subtarget->isThumb2()
                            ? ARM::fixup_t2_movw_lo16_pcrel
                            : ARM::fixup_arm_movw_lo16_pcrel);
diff --git a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index 4964c64242..78d73d3a27 100644
--- a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -256,27 +256,27 @@ static unsigned T2Morph2LoadLiteral(unsigned Opcode) {
   case ARM::t2LDR_POST:   case ARM::t2LDR_PRE:
   case ARM::t2LDRi12:     case ARM::t2LDRi8:
   case ARM::t2LDRs:       case ARM::t2LDRT:
-    return ARM::t2LDRi12;
+    return ARM::t2LDRpci;
 
   case ARM::t2LDRB_POST:  case ARM::t2LDRB_PRE:
   case ARM::t2LDRBi12:    case ARM::t2LDRBi8:
   case ARM::t2LDRBs:      case ARM::t2LDRBT:
-    return ARM::t2LDRBi12;
+    return ARM::t2LDRBpci;
 
   case ARM::t2LDRH_POST:  case ARM::t2LDRH_PRE:
   case ARM::t2LDRHi12:    case ARM::t2LDRHi8:
   case ARM::t2LDRHs:      case ARM::t2LDRHT:
-    return ARM::t2LDRHi12;
+    return ARM::t2LDRHpci;
 
   case ARM::t2LDRSB_POST:  case ARM::t2LDRSB_PRE:
   case ARM::t2LDRSBi12:    case ARM::t2LDRSBi8:
   case ARM::t2LDRSBs:      case ARM::t2LDRSBT:
-    return ARM::t2LDRSBi12;
+    return ARM::t2LDRSBpci;
 
   case ARM::t2LDRSH_POST:  case ARM::t2LDRSH_PRE:
   case ARM::t2LDRSHi12:    case ARM::t2LDRSHi8:
   case ARM::t2LDRSHs:      case ARM::t2LDRSHT:
-    return ARM::t2LDRSHi12;
+    return ARM::t2LDRSHpci;
   }
 }
 
@@ -531,9 +531,9 @@ static MCDisassembler *createThumbDisassembler(const Target &T) {
   return new ThumbDisassembler;
 }
 
-extern "C" void LLVMInitializeARMDisassembler() { 
+extern "C" void LLVMInitializeARMDisassembler() {
   // Register the disassembler.
-  TargetRegistry::RegisterMCDisassembler(TheARMTarget, 
+  TargetRegistry::RegisterMCDisassembler(TheARMTarget,
                                          createARMDisassembler);
   TargetRegistry::RegisterMCDisassembler(TheThumbTarget,
                                          createThumbDisassembler);
diff --git a/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h b/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h
index 0418543f83..8a38507a5a 100644
--- a/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h
+++ b/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h
@@ -564,6 +564,38 @@ static bool DisassembleThumb1LdPC(MCInst &MI, unsigned Opcode, uint32_t insn,
 // t_addrmode_sp := sp + imm8 * 4
 //
 
+// A8.6.63 LDRB (literal)
+// A8.6.79 LDRSB (literal)
+// A8.6.75 LDRH (literal)
+// A8.6.83 LDRSH (literal)
+// A8.6.59 LDR (literal)
+//
+// These instrs calculate an address from the PC value and an immediate offset.
+// Rd Rn=PC (+/-)imm12 (+ if Inst{23} == 0b1)
+static bool DisassembleThumb2Ldpci(MCInst &MI, unsigned Opcode,
+    uint32_t insn, unsigned short NumOps, unsigned &NumOpsAdded, BO B) {
+
+  const TargetOperandInfo *OpInfo = ARMInsts[Opcode].OpInfo;
+  if (!OpInfo) return false;
+
+  assert(NumOps >= 2 &&
+         OpInfo[0].RegClass == ARM::GPRRegClassID &&
+         OpInfo[1].RegClass < 0 &&
+         "Expect >= 2 operands, first as reg, and second as imm operand");
+
+  // Build the register operand, followed by the (+/-)imm12 immediate.
+
+  MI.addOperand(MCOperand::CreateReg(getRegisterEnum(B, ARM::GPRRegClassID,
+                                                     decodeRd(insn))));
+
+  MI.addOperand(MCOperand::CreateImm(decodeImm12(insn)));
+
+  NumOpsAdded = 2;
+
+  return true;
+}
+
+
 // A6.2.4 Load/store single data item
 //
 // Load/Store Register (reg|imm):      tRd tRn imm5 tRm
@@ -1755,7 +1787,7 @@ static bool DisassembleThumb2PreLoad(MCInst &MI, unsigned Opcode, uint32_t insn,
     if (slice(insn, 19, 16) == 0xFF) {
       bool Negative = slice(insn, 23, 23) == 0;
       unsigned Imm12 = getImm12(insn);
-      Offset = Negative ? -1 - Imm12 : 1 * Imm12;      
+      Offset = Negative ? -1 - Imm12 : 1 * Imm12;
     } else if (Opcode == ARM::t2PLDi8 || Opcode == ARM::t2PLDWi8 ||
                Opcode == ARM::t2PLIi8) {
       // A8.6.117 Encoding T2: add = FALSE
@@ -1812,6 +1844,9 @@ static bool DisassembleThumb2LdSt(bool Load, MCInst &MI, unsigned Opcode,
   if (Thumb2PreloadOpcode(Opcode))
     return DisassembleThumb2PreLoad(MI, Opcode, insn, NumOps, NumOpsAdded, B);
 
+  // See, for example, A6.3.7 Load word: Table A6-18 Load word.
+  if (Load && Rn == 15)
+    return DisassembleThumb2Ldpci(MI, Opcode, insn, NumOps, NumOpsAdded, B);
   const TargetInstrDesc &TID = ARMInsts[Opcode];
   const TargetOperandInfo *OpInfo = TID.OpInfo;
   unsigned &OpIdx = NumOpsAdded;
@@ -1858,7 +1893,7 @@ static bool DisassembleThumb2LdSt(bool Load, MCInst &MI, unsigned Opcode,
     else
       Imm = decodeImm8(insn);
   }
-  
+
   MI.addOperand(MCOperand::CreateReg(getRegisterEnum(B, ARM::GPRRegClassID,
                                                      R0)));
   ++OpIdx;
@@ -2183,7 +2218,7 @@ static bool DisassembleThumbFrm(MCInst &MI, unsigned Opcode, uint32_t insn,
   }
 
   // A6.3 32-bit Thumb instruction encoding
-  
+
   uint16_t op1 = slice(HalfWord, 12, 11);
   uint16_t op2 = slice(HalfWord, 10, 4);
   uint16_t op = slice(insn, 15, 15);
diff --git a/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp b/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
index 941c69d14e..4f03b8497b 100644
--- a/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
+++ b/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
@@ -574,9 +574,6 @@ void ARMInstPrinter::printAddrModeImm12Operand(const MCInst *MI, unsigned OpNum,
   if (!MO1.isReg()) {   // FIXME: This is for CP entries, but isn't right.
     printOperand(MI, OpNum, O);
     return;
-  } else if (MO1.getReg() == ARM::PC && MO2.isExpr()) {
-    printOperand(MI, OpNum+1, O);
-    return;
   }
 
   O << "[" << getRegisterName(MO1.getReg());
diff --git a/lib/Target/ARM/Thumb2SizeReduction.cpp b/lib/Target/ARM/Thumb2SizeReduction.cpp
index 3d7bcb23f8..cc8f61cd72 100644
--- a/lib/Target/ARM/Thumb2SizeReduction.cpp
+++ b/lib/Target/ARM/Thumb2SizeReduction.cpp
@@ -234,7 +234,7 @@ static bool VerifyLowRegs(MachineInstr *MI) {
   unsigned Opc = MI->getOpcode();
   bool isPCOk = (Opc == ARM::t2LDMIA_RET || Opc == ARM::t2LDMIA     ||
                  Opc == ARM::t2LDMDB     || Opc == ARM::t2LDMIA_UPD ||
-                 Opc == ARM::t2LDMDB_UPD || Opc == ARM::t2LDRi12);
+                 Opc == ARM::t2LDMDB_UPD);
   bool isLROk = (Opc == ARM::t2STMIA_UPD || Opc == ARM::t2STMDB_UPD);
   bool isSPOk = isPCOk || isLROk || (Opc == ARM::t2ADDrSPi);
   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
@@ -268,7 +268,6 @@ Thumb2SizeReduce::ReduceLoadStore(MachineBasicBlock &MBB, MachineInstr *MI,
     return false;
 
   unsigned Scale = 1;
-  bool HasBaseReg = true;
   bool HasImmOffset = false;
   bool HasShift = false;
   bool HasOffReg = true;
@@ -289,50 +288,19 @@ Thumb2SizeReduce::ReduceLoadStore(MachineBasicBlock &MBB, MachineInstr *MI,
     }
 
     Scale = 4;
-
-    if (MI->getOperand(2).isImm()) {
-      HasImmOffset = true;
-      HasOffReg = false;
-    } else {
-      // FIXME: Temporary workaround for a  bug introduced by r121082.
-      // We should use t2LDRpci for loads from constantpools.
-      // We don't want to narrow this to tLDRpci until constant island pass
-      // for fear of pessimizing code.
-      return false;
-    }
+    HasImmOffset = true;
+    HasOffReg = false;
     break;
   case ARM::t2LDRBi12:
   case ARM::t2STRBi12:
-    if (MI->getOperand(2).isImm()) {
-      HasImmOffset = true;
-      HasOffReg = false;
-    } else {
-      if (Entry.WideOpc == ARM::t2LDRBi12) {
-        Opc = ARM::tLDRpci;
-        OpNum = 2;
-      }
-
-      HasImmOffset = false;
-      HasBaseReg = false;
-      HasOffReg = false;
-    }
+    HasImmOffset = true;
+    HasOffReg = false;
     break;
   case ARM::t2LDRHi12:
   case ARM::t2STRHi12:
     Scale = 2;
-    if (MI->getOperand(2).isImm()) {
-      HasImmOffset = true;
-      HasOffReg = false;
-    } else {
-      if (Entry.WideOpc == ARM::t2LDRHi12) {
-        Opc = ARM::tLDRpci;
-        OpNum = 2;
-      }
-
-      HasImmOffset = false;
-      HasBaseReg = false;
-      HasOffReg = false;
-    }
+    HasImmOffset = true;
+    HasOffReg = false;
     break;
   case ARM::t2LDRs:
   case ARM::t2LDRBs:
@@ -426,9 +394,7 @@ Thumb2SizeReduce::ReduceLoadStore(MachineBasicBlock &MBB, MachineInstr *MI,
   MachineInstrBuilder MIB = BuildMI(MBB, *MI, dl, TII->get(Opc));
   if (!isLdStMul) {
     MIB.addOperand(MI->getOperand(0));
-
-    if (HasBaseReg)
-      MIB.addOperand(MI->getOperand(1));
+    MIB.addOperand(MI->getOperand(1));
 
     if (HasImmOffset)
       MIB.addImm(OffsetImm / Scale);
@@ -467,7 +433,7 @@ Thumb2SizeReduce::ReduceSpecial(MachineBasicBlock &MBB, MachineInstr *MI,
   unsigned Opc = MI->getOpcode();
   switch (Opc) {
   default: break;
-  case ARM::t2ADDSri: 
+  case ARM::t2ADDSri:
   case ARM::t2ADDSrr: {
     unsigned PredReg = 0;
     if (getInstrPredicate(MI, PredReg) == ARMCC::AL) {