Separate decoding for STREXD and LDREXD to make each work better.

llvm-svn: 137476

2 files changed, 24 insertions, 7 deletions

diff --git a/llvm/lib/Target/ARM/ARMInstrInfo.td b/llvm/lib/Target/ARM/ARMInstrInfo.td
index fe6a27c1c00..bfcb0f23d93 100644
--- a/llvm/lib/Target/ARM/ARMInstrInfo.td
+++ b/llvm/lib/Target/ARM/ARMInstrInfo.td
@@ -4082,7 +4082,7 @@ def LDREX  : AIldrex<0b00, (outs GPR:$Rt), (ins addr_offset_none:$addr),
 let hasExtraDefRegAllocReq = 1 in
 def LDREXD: AIldrex<0b01, (outs GPR:$Rt, GPR:$Rt2),(ins addr_offset_none:$addr),
                       NoItinerary, "ldrexd", "\t$Rt, $Rt2, $addr", []> {
-  let DecoderMethod = "DecodeDoubleRegExclusive";
+  let DecoderMethod = "DecodeDoubleRegLoad";
 }
 }
 
@@ -4099,7 +4099,7 @@ let hasExtraSrcRegAllocReq = 1, Constraints = "@earlyclobber $Rd" in
 def STREXD : AIstrex<0b01, (outs GPR:$Rd),
                     (ins GPR:$Rt, GPR:$Rt2, addr_offset_none:$addr),
                     NoItinerary, "strexd", "\t$Rd, $Rt, $Rt2, $addr", []> {
-  let DecoderMethod = "DecodeDoubleRegExclusive";
+  let DecoderMethod = "DecodeDoubleRegStore";
 }
 
 def CLREX : AXI<(outs), (ins), MiscFrm, NoItinerary, "clrex", []>,
diff --git a/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index 201ccf88928..805cf544734 100644
--- a/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -135,9 +135,10 @@ 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 DecodeDoubleRegExclusive(llvm::MCInst &Inst, unsigned Insn,
+static bool DecodeDoubleRegLoad(llvm::MCInst &Inst, unsigned Insn,
+                               uint64_t Address, const void *Decoder);
+static bool DecodeDoubleRegStore(llvm::MCInst &Inst, unsigned Insn,
                                uint64_t Address, const void *Decoder);
-
 
 static bool DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
                                uint64_t Address, const void *Decoder);
@@ -2486,15 +2487,31 @@ static bool DecodeMSRMask(llvm::MCInst &Inst, unsigned Val,
   return true;
 }
 
-static bool DecodeDoubleRegExclusive(llvm::MCInst &Inst, unsigned Insn,
+static bool DecodeDoubleRegLoad(llvm::MCInst &Inst, unsigned Insn,
+                                          uint64_t Address, const void *Decoder) {
+  unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
+  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
+  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
+
+  if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return false;
+
+  if (!DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)) return false;
+  if (!DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)) return false;
+  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
+  if (!DecodePredicateOperand(Inst, pred, Address, Decoder)) return false;
+
+  return true;
+}
+
+
+static bool DecodeDoubleRegStore(llvm::MCInst &Inst, unsigned Insn,
                                           uint64_t Address, const void *Decoder) {
   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
   unsigned Rt = fieldFromInstruction32(Insn, 0, 4);
   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
 
-  if (Inst.getOpcode() == ARM::STREXD)
-    if (!DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
+  if (!DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
 
   if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return false;
   if (Rd == Rn || Rd == Rt || Rd == Rt+1) return false;