Implement Thumb2 ldr.

After much back and forth, I decided to deviate from ARM design and split LDR into 4 instructions (r + imm12, r + imm8, r + r << imm12, constantpool). The advantage of this is 1) it follows the latest ARM technical manual, and 2) makes it easier to reduce the width of the instruction later. The down side is this creates more inconsistency between the two sub-targets. We should split ARM LDR instruction in a similar fashion later. I've added a README entry for this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74420 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp b/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
index 400f628..45c6727 100644
--- a/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
+++ b/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
@@ -93,45 +93,48 @@
       return "ARM Assembly Printer";
     }
 
-    void printOperand(const MachineInstr *MI, int opNum,
+    void printOperand(const MachineInstr *MI, int OpNum,
                       const char *Modifier = 0);
-    void printSOImmOperand(const MachineInstr *MI, int opNum);
-    void printSOImm2PartOperand(const MachineInstr *MI, int opNum);
-    void printSORegOperand(const MachineInstr *MI, int opNum);
-    void printAddrMode2Operand(const MachineInstr *MI, int OpNo);
-    void printAddrMode2OffsetOperand(const MachineInstr *MI, int OpNo);
-    void printAddrMode3Operand(const MachineInstr *MI, int OpNo);
-    void printAddrMode3OffsetOperand(const MachineInstr *MI, int OpNo);
-    void printAddrMode4Operand(const MachineInstr *MI, int OpNo,
+    void printSOImmOperand(const MachineInstr *MI, int OpNum);
+    void printSOImm2PartOperand(const MachineInstr *MI, int OpNum);
+    void printSORegOperand(const MachineInstr *MI, int OpNum);
+    void printAddrMode2Operand(const MachineInstr *MI, int OpNum);
+    void printAddrMode2OffsetOperand(const MachineInstr *MI, int OpNum);
+    void printAddrMode3Operand(const MachineInstr *MI, int OpNum);
+    void printAddrMode3OffsetOperand(const MachineInstr *MI, int OpNum);
+    void printAddrMode4Operand(const MachineInstr *MI, int OpNum,
                                const char *Modifier = 0);
-    void printAddrMode5Operand(const MachineInstr *MI, int OpNo,
+    void printAddrMode5Operand(const MachineInstr *MI, int OpNum,
                                const char *Modifier = 0);
-    void printAddrModePCOperand(const MachineInstr *MI, int OpNo,
+    void printAddrModePCOperand(const MachineInstr *MI, int OpNum,
                                 const char *Modifier = 0);
-    void printBitfieldInvMaskImmOperand (const MachineInstr *MI, int OpNo);
+    void printBitfieldInvMaskImmOperand (const MachineInstr *MI, int OpNum);
 
-    void printThumbAddrModeRROperand(const MachineInstr *MI, int OpNo);
-    void printThumbAddrModeRI5Operand(const MachineInstr *MI, int OpNo,
+    void printThumbAddrModeRROperand(const MachineInstr *MI, int OpNum);
+    void printThumbAddrModeRI5Operand(const MachineInstr *MI, int OpNum,
                                       unsigned Scale);
-    void printThumbAddrModeS1Operand(const MachineInstr *MI, int OpNo);
-    void printThumbAddrModeS2Operand(const MachineInstr *MI, int OpNo);
-    void printThumbAddrModeS4Operand(const MachineInstr *MI, int OpNo);
-    void printThumbAddrModeSPOperand(const MachineInstr *MI, int OpNo);
+    void printThumbAddrModeS1Operand(const MachineInstr *MI, int OpNum);
+    void printThumbAddrModeS2Operand(const MachineInstr *MI, int OpNum);
+    void printThumbAddrModeS4Operand(const MachineInstr *MI, int OpNum);
+    void printThumbAddrModeSPOperand(const MachineInstr *MI, int OpNum);
 
-    void printT2SOImmOperand(const MachineInstr *MI, int opNum);
+    void printT2SOImmOperand(const MachineInstr *MI, int OpNum);
     void printT2SOOperand(const MachineInstr *MI, int OpNum);
+    void printT2AddrModeImm12Operand(const MachineInstr *MI, int OpNum);
+    void printT2AddrModeImm8Operand(const MachineInstr *MI, int OpNum);
+    void printT2AddrModeSoRegOperand(const MachineInstr *MI, int OpNum);
 
-    void printPredicateOperand(const MachineInstr *MI, int opNum);
-    void printSBitModifierOperand(const MachineInstr *MI, int opNum);
-    void printPCLabel(const MachineInstr *MI, int opNum);
-    void printRegisterList(const MachineInstr *MI, int opNum);
-    void printCPInstOperand(const MachineInstr *MI, int opNum,
+    void printPredicateOperand(const MachineInstr *MI, int OpNum);
+    void printSBitModifierOperand(const MachineInstr *MI, int OpNum);
+    void printPCLabel(const MachineInstr *MI, int OpNum);
+    void printRegisterList(const MachineInstr *MI, int OpNum);
+    void printCPInstOperand(const MachineInstr *MI, int OpNum,
                             const char *Modifier);
-    void printJTBlockOperand(const MachineInstr *MI, int opNum);
+    void printJTBlockOperand(const MachineInstr *MI, int OpNum);
 
-    virtual bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
+    virtual bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
                                  unsigned AsmVariant, const char *ExtraCode);
-    virtual bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
+    virtual bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum,
                                        unsigned AsmVariant,
                                        const char *ExtraCode);
 
@@ -282,9 +285,9 @@
   return false;
 }
 
-void ARMAsmPrinter::printOperand(const MachineInstr *MI, int opNum,
+void ARMAsmPrinter::printOperand(const MachineInstr *MI, int OpNum,
                                  const char *Modifier) {
-  const MachineOperand &MO = MI->getOperand(opNum);
+  const MachineOperand &MO = MI->getOperand(OpNum);
   switch (MO.getType()) {
   case MachineOperand::MO_Register: {
     unsigned Reg = MO.getReg();
@@ -606,6 +609,8 @@
   O << "#" << lsb << ", #" << width;
 }
 
+//===--------------------------------------------------------------------===//
+
 void
 ARMAsmPrinter::printThumbAddrModeRROperand(const MachineInstr *MI, int Op) {
   const MachineOperand &MO1 = MI->getOperand(Op);
@@ -659,6 +664,8 @@
   O << "]";
 }
 
+//===--------------------------------------------------------------------===//
+
 /// printT2SOImmOperand - T2SOImm is:
 ///  1. a 4-bit splat control value and 8 bit immediate value
 ///  2. a 5-bit rotate amount and a non-zero 8-bit immediate value
@@ -694,47 +701,99 @@
   O << "#" << ARM_AM::getSORegOffset(MO2.getImm());
 }
 
+void ARMAsmPrinter::printT2AddrModeImm12Operand(const MachineInstr *MI,
+                                                int OpNum) {
+  const MachineOperand &MO1 = MI->getOperand(OpNum);
+  const MachineOperand &MO2 = MI->getOperand(OpNum+1);
 
-void ARMAsmPrinter::printPredicateOperand(const MachineInstr *MI, int opNum) {
-  ARMCC::CondCodes CC = (ARMCC::CondCodes)MI->getOperand(opNum).getImm();
+  O << "[" << TM.getRegisterInfo()->get(MO1.getReg()).AsmName;
+
+  unsigned OffImm = MO2.getImm();
+  if (OffImm)  // Don't print +0.
+    O << ", #+" << OffImm;
+  O << "]";
+}
+
+void ARMAsmPrinter::printT2AddrModeImm8Operand(const MachineInstr *MI,
+                                               int OpNum) {
+  const MachineOperand &MO1 = MI->getOperand(OpNum);
+  const MachineOperand &MO2 = MI->getOperand(OpNum+1);
+
+  O << "[" << TM.getRegisterInfo()->get(MO1.getReg()).AsmName;
+
+  int32_t OffImm = (int32_t)MO2.getImm();
+  // Don't print +0.
+  if (OffImm < 0)
+    O << ", #-" << -OffImm;
+  else if (OffImm > 0)
+    O << ", #+" << OffImm;
+  O << "]";
+}
+
+void ARMAsmPrinter::printT2AddrModeSoRegOperand(const MachineInstr *MI,
+                                                int OpNum) {
+  const MachineOperand &MO1 = MI->getOperand(OpNum);
+  const MachineOperand &MO2 = MI->getOperand(OpNum+1);
+  const MachineOperand &MO3 = MI->getOperand(OpNum+2);
+
+  O << "[" << TM.getRegisterInfo()->get(MO1.getReg()).AsmName;
+
+  if (MO2.getReg()) {
+    O << ", +"
+      << TM.getRegisterInfo()->get(MO2.getReg()).AsmName;
+
+    unsigned ShAmt = MO3.getImm();
+    if (ShAmt) {
+      assert(ShAmt <= 3 && "Not a valid Thumb2 addressing mode!");
+      O << ", lsl #" << ShAmt;
+    }
+  }
+  O << "]";
+}
+
+
+//===--------------------------------------------------------------------===//
+
+void ARMAsmPrinter::printPredicateOperand(const MachineInstr *MI, int OpNum) {
+  ARMCC::CondCodes CC = (ARMCC::CondCodes)MI->getOperand(OpNum).getImm();
   if (CC != ARMCC::AL)
     O << ARMCondCodeToString(CC);
 }
 
-void ARMAsmPrinter::printSBitModifierOperand(const MachineInstr *MI, int opNum){
-  unsigned Reg = MI->getOperand(opNum).getReg();
+void ARMAsmPrinter::printSBitModifierOperand(const MachineInstr *MI, int OpNum){
+  unsigned Reg = MI->getOperand(OpNum).getReg();
   if (Reg) {
     assert(Reg == ARM::CPSR && "Expect ARM CPSR register!");
     O << 's';
   }
 }
 
-void ARMAsmPrinter::printPCLabel(const MachineInstr *MI, int opNum) {
-  int Id = (int)MI->getOperand(opNum).getImm();
+void ARMAsmPrinter::printPCLabel(const MachineInstr *MI, int OpNum) {
+  int Id = (int)MI->getOperand(OpNum).getImm();
   O << TAI->getPrivateGlobalPrefix() << "PC" << Id;
 }
 
-void ARMAsmPrinter::printRegisterList(const MachineInstr *MI, int opNum) {
+void ARMAsmPrinter::printRegisterList(const MachineInstr *MI, int OpNum) {
   O << "{";
-  for (unsigned i = opNum, e = MI->getNumOperands(); i != e; ++i) {
+  for (unsigned i = OpNum, e = MI->getNumOperands(); i != e; ++i) {
     printOperand(MI, i);
     if (i != e-1) O << ", ";
   }
   O << "}";
 }
 
-void ARMAsmPrinter::printCPInstOperand(const MachineInstr *MI, int OpNo,
+void ARMAsmPrinter::printCPInstOperand(const MachineInstr *MI, int OpNum,
                                        const char *Modifier) {
   assert(Modifier && "This operand only works with a modifier!");
   // There are two aspects to a CONSTANTPOOL_ENTRY operand, the label and the
   // data itself.
   if (!strcmp(Modifier, "label")) {
-    unsigned ID = MI->getOperand(OpNo).getImm();
+    unsigned ID = MI->getOperand(OpNum).getImm();
     O << TAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber()
       << '_' << ID << ":\n";
   } else {
     assert(!strcmp(Modifier, "cpentry") && "Unknown modifier for CPE");
-    unsigned CPI = MI->getOperand(OpNo).getIndex();
+    unsigned CPI = MI->getOperand(OpNum).getIndex();
 
     const MachineConstantPoolEntry &MCPE = MCP->getConstants()[CPI];
     
@@ -746,9 +805,9 @@
   }
 }
 
-void ARMAsmPrinter::printJTBlockOperand(const MachineInstr *MI, int OpNo) {
-  const MachineOperand &MO1 = MI->getOperand(OpNo);
-  const MachineOperand &MO2 = MI->getOperand(OpNo+1); // Unique Id
+void ARMAsmPrinter::printJTBlockOperand(const MachineInstr *MI, int OpNum) {
+  const MachineOperand &MO1 = MI->getOperand(OpNum);
+  const MachineOperand &MO2 = MI->getOperand(OpNum+1); // Unique Id
   unsigned JTI = MO1.getIndex();
   O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
     << '_' << JTI << '_' << MO2.getImm() << ":\n";
@@ -787,7 +846,7 @@
 }
 
 
-bool ARMAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
+bool ARMAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
                                     unsigned AsmVariant, const char *ExtraCode){
   // Does this asm operand have a single letter operand modifier?
   if (ExtraCode && ExtraCode[0]) {
@@ -797,10 +856,10 @@
     default: return true;  // Unknown modifier.
     case 'a': // Don't print "#" before a global var name or constant.
     case 'c': // Don't print "$" before a global var name or constant.
-      printOperand(MI, OpNo, "no_hash");
+      printOperand(MI, OpNum, "no_hash");
       return false;
     case 'P': // Print a VFP double precision register.
-      printOperand(MI, OpNo);
+      printOperand(MI, OpNum);
       return false;
     case 'Q':
       if (TM.getTargetData()->isLittleEndian())
@@ -812,24 +871,24 @@
       // Fallthrough
     case 'H': // Write second word of DI / DF reference.  
       // Verify that this operand has two consecutive registers.
-      if (!MI->getOperand(OpNo).isReg() ||
-          OpNo+1 == MI->getNumOperands() ||
-          !MI->getOperand(OpNo+1).isReg())
+      if (!MI->getOperand(OpNum).isReg() ||
+          OpNum+1 == MI->getNumOperands() ||
+          !MI->getOperand(OpNum+1).isReg())
         return true;
-      ++OpNo;   // Return the high-part.
+      ++OpNum;   // Return the high-part.
     }
   }
   
-  printOperand(MI, OpNo);
+  printOperand(MI, OpNum);
   return false;
 }
 
 bool ARMAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
-                                          unsigned OpNo, unsigned AsmVariant,
+                                          unsigned OpNum, unsigned AsmVariant,
                                           const char *ExtraCode) {
   if (ExtraCode && ExtraCode[0])
     return true; // Unknown modifier.
-  printAddrMode2Operand(MI, OpNo);
+  printAddrMode2Operand(MI, OpNum);
   return false;
 }