ARM assembly parsing and encoding for RFE instruction.

Fill in the missing fixed bits and the register operand bits of the instruction
encoding. Refactor the definition to make the mode explicit, which is
consistent with how loads and stores are normally represented and makes
parsing much easier. Add parsing aliases for pseudo-instruction variants.
Update the disassembler for the new representations. Add tests for parsing and
encoding.

llvm-svn: 136479

1 files changed, 11 insertions, 4 deletions

diff --git a/llvm/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp b/llvm/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp
index 1f3920bd8cf..983589f6983 100644
--- a/llvm/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp
+++ b/llvm/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp
@@ -799,7 +799,7 @@ static bool DisassembleCoprocessor(MCInst &MI, unsigned Opcode, uint32_t insn,
 // BXJ:        Rm
 // MSRi/MSRsysi: so_imm
 // SRSW/SRS: ldstm_mode:$amode mode_imm
-// RFEW/RFE: ldstm_mode:$amode Rn
+// RFE: Rn
 static bool DisassembleBrFrm(MCInst &MI, unsigned Opcode, uint32_t insn,
     unsigned short NumOps, unsigned &NumOpsAdded, BO B) {
 
@@ -858,19 +858,26 @@ static bool DisassembleBrFrm(MCInst &MI, unsigned Opcode, uint32_t insn,
     NumOpsAdded = 2;
     return true;
   }
-  if (Opcode == ARM::SRSW || Opcode == ARM::SRS ||
-      Opcode == ARM::RFEW || Opcode == ARM::RFE) {
+  if (Opcode == ARM::SRSW || Opcode == ARM::SRS) {
     ARM_AM::AMSubMode SubMode = getAMSubModeForBits(getPUBits(insn));
     MI.addOperand(MCOperand::CreateImm(ARM_AM::getAM4ModeImm(SubMode)));
 
     if (Opcode == ARM::SRSW || Opcode == ARM::SRS)
       MI.addOperand(MCOperand::CreateImm(slice(insn, 4, 0)));
-    else
       MI.addOperand(MCOperand::CreateReg(getRegisterEnum(B, ARM::GPRRegClassID,
                                                          decodeRn(insn))));
     NumOpsAdded = 3;
     return true;
   }
+  if (Opcode == ARM::RFEDA || Opcode == ARM::RFEDB ||
+      Opcode == ARM::RFEIA || Opcode == ARM::RFEIB ||
+      Opcode == ARM::RFEDA_UPD || Opcode == ARM::RFEDB_UPD ||
+      Opcode == ARM::RFEIA_UPD || Opcode == ARM::RFEIB_UPD) {
+    MI.addOperand(MCOperand::CreateReg(getRegisterEnum(B, ARM::GPRRegClassID,
+                                                       decodeRn(insn))));
+    NumOpsAdded = 1;
+    return true;
+  }
 
   assert((Opcode == ARM::Bcc || Opcode == ARM::BL || Opcode == ARM::BL_pred
           || Opcode == ARM::SMC || Opcode == ARM::SVC) &&