Apply again changes to support ARM memory asm parsing. I removed
all LDR/STR changes and left them to a future patch. Passing all
checks now.

- Implement asm parsing support for LDRT, LDRBT, STRT, STRBT and
  fix the encoding wherever is possible.
- Add a new encoding bit to describe the index mode used and teach
  printAddrMode2Operand to check by the addressing mode which index
  mode to print.
- Testcases

llvm-svn: 128689
diff --git a/llvm/lib/Target/ARM/ARMInstrInfo.td b/llvm/lib/Target/ARM/ARMInstrInfo.td
index 18127f3..34e86f9 100644
--- a/llvm/lib/Target/ARM/ARMInstrInfo.td
+++ b/llvm/lib/Target/ARM/ARMInstrInfo.td
@@ -498,6 +498,12 @@
   let MIOperandInfo = (ops GPR:$base, GPR:$offsreg, i32imm:$offsimm);
 }
 
+def MemMode2AsmOperand : AsmOperandClass {
+  let Name = "MemMode2";
+  let SuperClasses = [];
+  let ParserMethod = "tryParseMemMode2Operand";
+}
+
 // addrmode2 := reg +/- imm12
 //           := reg +/- reg shop imm
 //
@@ -505,6 +511,7 @@
                 ComplexPattern<i32, 3, "SelectAddrMode2", []> {
   let EncoderMethod = "getAddrMode2OpValue";
   let PrintMethod = "printAddrMode2Operand";
+  let ParserMatchClass = MemMode2AsmOperand;
   let MIOperandInfo = (ops GPR:$base, GPR:$offsreg, i32imm:$offsimm);
 }
 
@@ -1668,6 +1675,7 @@
     let Inst{23} = addr{12};
     let Inst{19-16} = addr{17-14};
     let Inst{11-0} = addr{11-0};
+    let AsmMatchConverter = "CvtLdWriteBackRegAddrMode2";
   }
   def _POST : AI2ldstidx<1, isByte, 0, (outs GPR:$Rt, GPR:$Rn_wb),
                       (ins GPR:$Rn, am2offset:$offset),
@@ -1726,17 +1734,35 @@
 
 // LDRT, LDRBT, LDRSBT, LDRHT, LDRSHT are for disassembly only.
 let mayLoad = 1, neverHasSideEffects = 1 in {
-def LDRT : AI2ldstidx<1, 0, 0, (outs GPR:$dst, GPR:$base_wb),
-                   (ins GPR:$base, am2offset:$offset), IndexModePost,
-                   LdFrm, IIC_iLoad_ru,
-                   "ldrt", "\t$dst, [$base], $offset", "$base = $base_wb", []> {
+def LDRT : AI2ldstidx<1, 0, 0, (outs GPR:$Rt, GPR:$base_wb),
+                   (ins addrmode2:$addr), IndexModePost, LdFrm, IIC_iLoad_ru,
+                   "ldrt", "\t$Rt, $addr", "$addr.base = $base_wb", []> {
+  // {17-14}  Rn
+  // {13}     1 == Rm, 0 == imm12
+  // {12}     isAdd
+  // {11-0}   imm12/Rm
+  bits<18> addr;
+  let Inst{25} = addr{13};
+  let Inst{23} = addr{12};
   let Inst{21} = 1; // overwrite
+  let Inst{19-16} = addr{17-14};
+  let Inst{11-0} = addr{11-0};
+  let AsmMatchConverter = "CvtLdWriteBackRegAddrMode2";
 }
-def LDRBT : AI2ldstidx<1, 1, 0, (outs GPR:$dst, GPR:$base_wb),
-                  (ins GPR:$base, am2offset:$offset), IndexModePost,
-                  LdFrm, IIC_iLoad_bh_ru,
-                  "ldrbt", "\t$dst, [$base], $offset", "$base = $base_wb", []> {
+def LDRBT : AI2ldstidx<1, 1, 0, (outs GPR:$Rt, GPR:$base_wb),
+                  (ins addrmode2:$addr), IndexModePost, LdFrm, IIC_iLoad_bh_ru,
+                  "ldrbt", "\t$Rt, $addr", "$addr.base = $base_wb", []> {
+  // {17-14}  Rn
+  // {13}     1 == Rm, 0 == imm12
+  // {12}     isAdd
+  // {11-0}   imm12/Rm
+  bits<18> addr;
+  let Inst{25} = addr{13};
+  let Inst{23} = addr{12};
   let Inst{21} = 1; // overwrite
+  let Inst{19-16} = addr{17-14};
+  let Inst{11-0} = addr{11-0};
+  let AsmMatchConverter = "CvtLdWriteBackRegAddrMode2";
 }
 def LDRSBT : AI3ldstidx<0b1101, 1, 1, 0, (outs GPR:$dst, GPR:$base_wb),
                  (ins GPR:$base, am3offset:$offset), IndexModePost,
@@ -1830,20 +1856,20 @@
 
 // STRT, STRBT, and STRHT are for disassembly only.
 
-def STRT : AI2stridx<0, 0, (outs GPR:$Rn_wb),
-                    (ins GPR:$Rt, GPR:$Rn,am2offset:$offset),
-                    IndexModePost, StFrm, IIC_iStore_ru,
-                    "strt", "\t$Rt, [$Rn], $offset", "$Rn = $Rn_wb",
-                    [/* For disassembly only; pattern left blank */]> {
-  let Inst{21} = 1; // overwrite
-}
-
-def STRBT : AI2stridx<1, 0, (outs GPR:$Rn_wb),
-                     (ins GPR:$Rt, GPR:$Rn, am2offset:$offset),
-                     IndexModePost, StFrm, IIC_iStore_bh_ru,
-                     "strbt", "\t$Rt, [$Rn], $offset", "$Rn = $Rn_wb",
+def STRT : AI2stridxT<0, 0, (outs GPR:$Rn_wb), (ins GPR:$Rt, addrmode2:$addr),
+                     IndexModePost, StFrm, IIC_iStore_ru,
+                     "strt", "\t$Rt, $addr", "$addr.base = $Rn_wb",
                      [/* For disassembly only; pattern left blank */]> {
   let Inst{21} = 1; // overwrite
+  let AsmMatchConverter = "CvtStWriteBackRegAddrMode2";
+}
+
+def STRBT : AI2stridxT<1, 0, (outs GPR:$Rn_wb), (ins GPR:$Rt, addrmode2:$addr),
+                      IndexModePost, StFrm, IIC_iStore_bh_ru,
+                      "strbt", "\t$Rt, $addr", "$addr.base = $Rn_wb",
+                      [/* For disassembly only; pattern left blank */]> {
+  let Inst{21} = 1; // overwrite
+  let AsmMatchConverter = "CvtStWriteBackRegAddrMode2";
 }
 
 def STRHT: AI3sthpo<(outs GPR:$base_wb),
@@ -3403,8 +3429,9 @@
   let Inst{23-20} = opc1;
 }
 
-class ACI<dag oops, dag iops, string opc, string asm>
-  : I<oops, iops, AddrModeNone, Size4Bytes, IndexModeNone, BrFrm, NoItinerary,
+class ACI<dag oops, dag iops, string opc, string asm,
+          IndexMode im = IndexModeNone>
+  : I<oops, iops, AddrModeNone, Size4Bytes, im, BrFrm, NoItinerary,
       opc, asm, "", [/* For disassembly only; pattern left blank */]> {
   let Inst{27-25} = 0b110;
 }
@@ -3423,7 +3450,7 @@
 
   def _PRE : ACI<(outs),
       (ins nohash_imm:$cop, nohash_imm:$CRd, addrmode2:$addr),
-      opc, "\tp$cop, cr$CRd, $addr!"> {
+      opc, "\tp$cop, cr$CRd, $addr!", IndexModePre> {
     let Inst{31-28} = op31_28;
     let Inst{24} = 1; // P = 1
     let Inst{21} = 1; // W = 1
@@ -3432,8 +3459,8 @@
   }
 
   def _POST : ACI<(outs),
-      (ins nohash_imm:$cop, nohash_imm:$CRd, GPR:$base, am2offset:$offset),
-      opc, "\tp$cop, cr$CRd, [$base], $offset"> {
+      (ins nohash_imm:$cop, nohash_imm:$CRd, addrmode2:$addr),
+      opc, "\tp$cop, cr$CRd, $addr", IndexModePost> {
     let Inst{31-28} = op31_28;
     let Inst{24} = 0; // P = 0
     let Inst{21} = 1; // W = 1
@@ -3464,7 +3491,7 @@
 
   def L_PRE : ACI<(outs),
       (ins nohash_imm:$cop, nohash_imm:$CRd, addrmode2:$addr),
-      !strconcat(opc, "l"), "\tp$cop, cr$CRd, $addr!"> {
+      !strconcat(opc, "l"), "\tp$cop, cr$CRd, $addr!", IndexModePre> {
     let Inst{31-28} = op31_28;
     let Inst{24} = 1; // P = 1
     let Inst{21} = 1; // W = 1
@@ -3473,8 +3500,8 @@
   }
 
   def L_POST : ACI<(outs),
-      (ins nohash_imm:$cop, nohash_imm:$CRd, GPR:$base, am2offset:$offset),
-      !strconcat(opc, "l"), "\tp$cop, cr$CRd, [$base], $offset"> {
+      (ins nohash_imm:$cop, nohash_imm:$CRd, addrmode2:$addr),
+      !strconcat(opc, "l"), "\tp$cop, cr$CRd, $addr", IndexModePost> {
     let Inst{31-28} = op31_28;
     let Inst{24} = 0; // P = 0
     let Inst{21} = 1; // W = 1