Added support for unpredictable mcrr/mcrr2/mrrc/mrrc2 ARM instruction…

… in the disassembler. Since the upredicability conditions are complex, C++ code was added to handle them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155001 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/ARM/ARMInstrInfo.td

@@ -4590,7 +4590,7 @@ def : ARMV5TPat<(int_arm_mrc2 imm:$cop, imm:$opc1, imm:$CRn,
 
 class MovRRCopro<string opc, bit direction, list<dag> pattern = []>
   : ABI<0b1100, (outs), (ins p_imm:$cop, imm0_15:$opc1,
-        GPR:$Rt, GPR:$Rt2, c_imm:$CRm),
+        GPRnopc:$Rt, GPRnopc:$Rt2, c_imm:$CRm),
         NoItinerary, opc, "\t$cop, $opc1, $Rt, $Rt2, $CRm", pattern> {
   let Inst{23-21} = 0b010;
   let Inst{20} = direction;
@@ -4609,13 +4609,13 @@ class MovRRCopro<string opc, bit direction, list<dag> pattern = []>
 }
 
 def MCRR : MovRRCopro<"mcrr", 0 /* from ARM core register to coprocessor */,
-                      [(int_arm_mcrr imm:$cop, imm:$opc1, GPR:$Rt, GPR:$Rt2,
+                      [(int_arm_mcrr imm:$cop, imm:$opc1, GPRnopc:$Rt, GPRnopc:$Rt2,
                                      imm:$CRm)]>;
 def MRRC : MovRRCopro<"mrrc", 1 /* from coprocessor to ARM core register */>;
 
 class MovRRCopro2<string opc, bit direction, list<dag> pattern = []>
   : ABXI<0b1100, (outs), (ins p_imm:$cop, imm0_15:$opc1,
-         GPR:$Rt, GPR:$Rt2, c_imm:$CRm), NoItinerary,
+         GPRnopc:$Rt, GPRnopc:$Rt2, c_imm:$CRm), NoItinerary,
          !strconcat(opc, "\t$cop, $opc1, $Rt, $Rt2, $CRm"), pattern> {
   let Inst{31-28} = 0b1111;
   let Inst{23-21} = 0b010;
@@ -4632,10 +4632,12 @@ class MovRRCopro2<string opc, bit direction, list<dag> pattern = []>
   let Inst{11-8}  = cop;
   let Inst{7-4}   = opc1;
   let Inst{3-0}   = CRm;
+
+  let DecoderMethod = "DecodeMRRC2";
 }
 
 def MCRR2 : MovRRCopro2<"mcrr2", 0 /* from ARM core register to coprocessor */,
-                        [(int_arm_mcrr2 imm:$cop, imm:$opc1, GPR:$Rt, GPR:$Rt2,
+                        [(int_arm_mcrr2 imm:$cop, imm:$opc1, GPRnopc:$Rt, GPRnopc:$Rt2,
                                         imm:$CRm)]>;
 def MRRC2 : MovRRCopro2<"mrrc2", 1 /* from coprocessor to ARM core register */>;
 

lib/Target/ARM/Disassembler/ARMDisassembler.cpp

@@ -326,6 +326,8 @@ static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
 
 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
                                 uint64_t Address, const void *Decoder);
+static DecodeStatus DecodeMRRC2(llvm::MCInst &Inst, unsigned Val,
+                                uint64_t Address, const void *Decoder);
 #include "ARMGenDisassemblerTables.inc"
 #include "ARMGenInstrInfo.inc"
 #include "ARMGenEDInfo.inc"
@@ -4403,3 +4405,31 @@ static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
   return S;
 }
 
+static DecodeStatus DecodeMRRC2(llvm::MCInst &Inst, unsigned Val,
+                                uint64_t Address, const void *Decoder) {
+
+  DecodeStatus S = MCDisassembler::Success;
+
+  unsigned CRm = fieldFromInstruction32(Val, 0, 4);
+  unsigned opc1 = fieldFromInstruction32(Val, 4, 4);
+  unsigned cop = fieldFromInstruction32(Val, 8, 4);
+  unsigned Rt = fieldFromInstruction32(Val, 12, 4);
+  unsigned Rt2 = fieldFromInstruction32(Val, 16, 4);
+
+  if ((cop & ~0x1) == 0xa)
+    return MCDisassembler::Fail;
+
+  if (Rt == Rt2)
+    S = MCDisassembler::SoftFail;
+
+  Inst.addOperand(MCOperand::CreateImm(cop));
+  Inst.addOperand(MCOperand::CreateImm(opc1));
+  if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
+    return MCDisassembler::Fail;
+  if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
+    return MCDisassembler::Fail;
+  Inst.addOperand(MCOperand::CreateImm(CRm));
+
+  return S;
+}
+

test/MC/Disassembler/ARM/invalid-MRRC2-arm.txt

@@ -0,0 +1,4 @@
+# RUN: llvm-mc --disassemble %s -triple=armv7-linux-gnueabi |& FileCheck %s
+
+# CHECK: invalid instruction encoding
+0x00 0x1a 0x50 0xfc

test/MC/Disassembler/ARM/unpredictable-MRRC2-arm.txt

@@ -0,0 +1,13 @@
+# RUN: llvm-mc --disassemble %s -triple=armv7-linux-gnueabi |& FileCheck %s
+
+# CHECK: potentially undefined
+# CHECK: 0x00 0x10 0x51 0xfc
+0x00 0x10 0x51 0xfc
+
+# CHECK: potentially undefined
+# CHECK: 0x00 0xf0 0x41 0x0c
+0x00 0xf0 0x41 0x0c
+
+# CHECK: potentially undefined
+# CHECK: 0x00 0x00 0x4f 0x0c
+0x00 0x00 0x4f 0x0c