3 files changed, 75 insertions, 2 deletions
diff --git a/lib/Target/ARM/ARMInstrFormats.td b/lib/Target/ARM/ARMInstrFormats.td
index d7446ffe1a..579f3835bc 100644
--- a/lib/Target/ARM/ARMInstrFormats.td
+++ b/lib/Target/ARM/ARMInstrFormats.td
@@ -189,6 +189,7 @@ def MSRMaskOperand : AsmOperandClass {
 }
 def msr_mask : Operand<i32> {
   let PrintMethod = "printMSRMaskOperand";
+  let DecoderMethod = "DecodeMSRMask";
   let ParserMatchClass = MSRMaskOperand;
 }
 
diff --git a/lib/Target/ARM/ARMInstrInfo.td b/lib/Target/ARM/ARMInstrInfo.td
index ae408ce9bc..c8eb025731 100644
--- a/lib/Target/ARM/ARMInstrInfo.td
+++ b/lib/Target/ARM/ARMInstrInfo.td
@@ -1259,6 +1259,37 @@ multiclass AI_ldr1<bit isByte, string opc, InstrItinClass iii,
 }
 }
 
+let canFoldAsLoad = 1, isReMaterializable = 1 in {
+multiclass AI_ldr1nopc<bit isByte, string opc, InstrItinClass iii,
+           InstrItinClass iir, PatFrag opnode> {
+  // Note: We use the complex addrmode_imm12 rather than just an input
+  // GPR and a constrained immediate so that we can use this to match
+  // frame index references and avoid matching constant pool references.
+  def i12: AI2ldst<0b010, 1, isByte, (outs GPRnopc:$Rt), (ins addrmode_imm12:$addr),
+                   AddrMode_i12, LdFrm, iii, opc, "\t$Rt, $addr",
+                  [(set GPRnopc:$Rt, (opnode addrmode_imm12:$addr))]> {
+    bits<4>  Rt;
+    bits<17> addr;
+    let Inst{23}    = addr{12};     // U (add = ('U' == 1))
+    let Inst{19-16} = addr{16-13};  // Rn
+    let Inst{15-12} = Rt;
+    let Inst{11-0}  = addr{11-0};   // imm12
+  }
+  def rs : AI2ldst<0b011, 1, isByte, (outs GPRnopc:$Rt), (ins ldst_so_reg:$shift),
+                  AddrModeNone, LdFrm, iir, opc, "\t$Rt, $shift",
+                 [(set GPRnopc:$Rt, (opnode ldst_so_reg:$shift))]> {
+    bits<4>  Rt;
+    bits<17> shift;
+    let shift{4}    = 0;            // Inst{4} = 0
+    let Inst{23}    = shift{12};    // U (add = ('U' == 1))
+    let Inst{19-16} = shift{16-13}; // Rn
+    let Inst{15-12} = Rt;
+    let Inst{11-0}  = shift{11-0};
+  }
+}
+}
+
+
 multiclass AI_str1<bit isByte, string opc, InstrItinClass iii,
            InstrItinClass iir, PatFrag opnode> {
   // Note: We use the complex addrmode_imm12 rather than just an input
@@ -1287,6 +1318,37 @@ multiclass AI_str1<bit isByte, string opc, InstrItinClass iii,
     let Inst{11-0}  = shift{11-0};
   }
 }
+
+multiclass AI_str1nopc<bit isByte, string opc, InstrItinClass iii,
+           InstrItinClass iir, PatFrag opnode> {
+  // Note: We use the complex addrmode_imm12 rather than just an input
+  // GPR and a constrained immediate so that we can use this to match
+  // frame index references and avoid matching constant pool references.
+  def i12 : AI2ldst<0b010, 0, isByte, (outs),
+                   (ins GPRnopc:$Rt, addrmode_imm12:$addr),
+                   AddrMode_i12, StFrm, iii, opc, "\t$Rt, $addr",
+                  [(opnode GPRnopc:$Rt, addrmode_imm12:$addr)]> {
+    bits<4> Rt;
+    bits<17> addr;
+    let Inst{23}    = addr{12};     // U (add = ('U' == 1))
+    let Inst{19-16} = addr{16-13};  // Rn
+    let Inst{15-12} = Rt;
+    let Inst{11-0}  = addr{11-0};   // imm12
+  }
+  def rs : AI2ldst<0b011, 0, isByte, (outs), (ins GPRnopc:$Rt, ldst_so_reg:$shift),
+                  AddrModeNone, StFrm, iir, opc, "\t$Rt, $shift",
+                 [(opnode GPRnopc:$Rt, ldst_so_reg:$shift)]> {
+    bits<4> Rt;
+    bits<17> shift;
+    let shift{4}    = 0;            // Inst{4} = 0
+    let Inst{23}    = shift{12};    // U (add = ('U' == 1))
+    let Inst{19-16} = shift{16-13}; // Rn
+    let Inst{15-12} = Rt;
+    let Inst{11-0}  = shift{11-0};
+  }
+}
+
+
 //===----------------------------------------------------------------------===//
 // Instructions
 //===----------------------------------------------------------------------===//
@@ -1894,11 +1956,11 @@ def RFEIB_UPD : RFEI<1, "rfeib\t$Rn!"> {
 
 defm LDR  : AI_ldr1<0, "ldr", IIC_iLoad_r, IIC_iLoad_si,
                     UnOpFrag<(load node:$Src)>>;
-defm LDRB : AI_ldr1<1, "ldrb", IIC_iLoad_bh_r, IIC_iLoad_bh_si,
+defm LDRB : AI_ldr1nopc<1, "ldrb", IIC_iLoad_bh_r, IIC_iLoad_bh_si,
                     UnOpFrag<(zextloadi8 node:$Src)>>;
 defm STR  : AI_str1<0, "str", IIC_iStore_r, IIC_iStore_si,
                    BinOpFrag<(store node:$LHS, node:$RHS)>>;
-defm STRB : AI_str1<1, "strb", IIC_iStore_bh_r, IIC_iStore_bh_si,
+defm STRB : AI_str1nopc<1, "strb", IIC_iStore_bh_r, IIC_iStore_bh_si,
                    BinOpFrag<(truncstorei8 node:$LHS, node:$RHS)>>;
 
 // Special LDR for loads from non-pc-relative constpools.
diff --git a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index d5994220a0..8cfb21793e 100644
--- a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -133,6 +133,8 @@ static bool DecodeAddrMode3Offset(llvm::MCInst &Inst, unsigned Insn,
                                uint64_t Address, const void *Decoder);
 static bool DecodeMemBarrierOption(llvm::MCInst &Inst, unsigned Insn,
                                uint64_t Address, const void *Decoder);
+static bool DecodeMSRMask(llvm::MCInst &Inst, unsigned Insn,
+                               uint64_t Address, const void *Decoder);
 
 
 static bool DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
@@ -759,6 +761,8 @@ static bool DecodeSORegRegOperand(llvm::MCInst &Inst, unsigned Val,
 
 static bool DecodeRegListOperand(llvm::MCInst &Inst, unsigned Val,
                                  uint64_t Address, const void *Decoder) {
+  // Empty register lists are not allowed.
+  if (CountPopulation_32(Val) == 0) return false;
   for (unsigned i = 0; i < 16; ++i) {
     if (Val & (1 << i)) {
       if (!DecodeGPRRegisterClass(Inst, i, Address, Decoder)) return false;
@@ -2467,3 +2471,9 @@ static bool DecodeMemBarrierOption(llvm::MCInst &Inst, unsigned Val,
   return true;
 }
 
+static bool DecodeMSRMask(llvm::MCInst &Inst, unsigned Val,
+                          uint64_t Address, const void *Decoder) {
+  if (!Val) return false;
+  Inst.addOperand(MCOperand::CreateImm(Val));
+  return true;
+}