- Implement asm parsing support for LDRT, LDRBT, STRT, STRBT and
  {STR,LDC}{2}_PRE.
- Fixed the encoding in some places.
- Some of those instructions were using am2offset and now use addrmode2.
Codegen isn't affected, instructions which use SelectAddrMode2Offset were not
touched.
- Teach printAddrMode2Operand to check by the addressing mode which index
mode to print.
- This is a work in progress, more work to come. The idea is to change places
which use am2offset to use addrmode2 instead, as to unify assembly parser.
- Add testcases for assembly parser

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128585 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp b/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
index 3220627..c998748 100644
--- a/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
+++ b/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
@@ -14,6 +14,7 @@
 #define DEBUG_TYPE "asm-printer"
 #include "ARMBaseInfo.h"
 #include "ARMInstPrinter.h"
+#include "ARMInstrInfo.h"
 #include "ARMAddressingModes.h"
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCAsmInfo.h"
@@ -181,18 +182,12 @@
   }
 }
 
-
-void ARMInstPrinter::printAddrMode2Operand(const MCInst *MI, unsigned Op,
-                                           raw_ostream &O) {
+void ARMInstPrinter::printAM2PreOrOffsetIndexOp(const MCInst *MI, unsigned Op,
+                                                raw_ostream &O) {
   const MCOperand &MO1 = MI->getOperand(Op);
   const MCOperand &MO2 = MI->getOperand(Op+1);
   const MCOperand &MO3 = MI->getOperand(Op+2);
 
-  if (!MO1.isReg()) {   // FIXME: This is for CP entries, but isn't right.
-    printOperand(MI, Op, O);
-    return;
-  }
-
   O << "[" << getRegisterName(MO1.getReg());
 
   if (!MO2.getReg()) {
@@ -215,6 +210,52 @@
   O << "]";
 }
 
+void ARMInstPrinter::printAM2PostIndexOp(const MCInst *MI, unsigned Op,
+                                         raw_ostream &O) {
+  const MCOperand &MO1 = MI->getOperand(Op);
+  const MCOperand &MO2 = MI->getOperand(Op+1);
+  const MCOperand &MO3 = MI->getOperand(Op+2);
+
+  O << "[" << getRegisterName(MO1.getReg()) << "], ";
+
+  if (!MO2.getReg()) {
+    unsigned ImmOffs = ARM_AM::getAM2Offset(MO3.getImm());
+    O << '#'
+      << ARM_AM::getAddrOpcStr(ARM_AM::getAM2Op(MO3.getImm()))
+      << ImmOffs;
+    return;
+  }
+
+  O << ARM_AM::getAddrOpcStr(ARM_AM::getAM2Op(MO3.getImm()))
+    << getRegisterName(MO2.getReg());
+
+  if (unsigned ShImm = ARM_AM::getAM2Offset(MO3.getImm()))
+    O << ", "
+    << ARM_AM::getShiftOpcStr(ARM_AM::getAM2ShiftOpc(MO3.getImm()))
+    << " #" << ShImm;
+}
+
+void ARMInstPrinter::printAddrMode2Operand(const MCInst *MI, unsigned Op,
+                                           raw_ostream &O) {
+  const MCOperand &MO1 = MI->getOperand(Op);
+
+  if (!MO1.isReg()) {   // FIXME: This is for CP entries, but isn't right.
+    printOperand(MI, Op, O);
+    return;
+  }
+
+  unsigned Opcode = MI->getOpcode();
+  const TargetInstrDesc &Desc = TM.getInstrInfo()->get(Opcode);
+  uint64_t TSFlags = Desc.TSFlags;
+  unsigned IdxMode = (TSFlags & ARMII::IndexModeMask) >> ARMII::IndexModeShift;
+
+  if (IdxMode == ARMII::IndexModePost) {
+    printAM2PostIndexOp(MI, Op, O);
+    return;
+  }
+  printAM2PreOrOffsetIndexOp(MI, Op, O);
+}
+
 void ARMInstPrinter::printAddrMode2OffsetOperand(const MCInst *MI,
                                                  unsigned OpNum,
                                                  raw_ostream &O) {