Fix an ambiguous decoding where we failed to properly decode VMOVv2f32 and VMOVv4f32.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144683 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 66 insertions, 8 deletions

diff --git a/lib/Target/ARM/ARMInstrNEON.td b/lib/Target/ARM/ARMInstrNEON.td
index d24a8f5..417f181 100644
--- a/lib/Target/ARM/ARMInstrNEON.td
+++ b/lib/Target/ARM/ARMInstrNEON.td
@@ -4815,6 +4815,7 @@ def  VCVTu2fq : N2VQ<0b11, 0b11, 0b10, 0b11, 0b01101, 0, "vcvt", "f32.u32",
                      v4f32, v4i32, uint_to_fp>;
 
 //   VCVT     : Vector Convert Between Floating-Point and Fixed-Point.
+let DecoderMethod = "DecodeVCVTD" in {
 def VCVTf2xsd : N2VCvtD<0, 1, 0b1111, 0, 1, "vcvt", "s32.f32",
                         v2i32, v2f32, int_arm_neon_vcvtfp2fxs>;
 def VCVTf2xud : N2VCvtD<1, 1, 0b1111, 0, 1, "vcvt", "u32.f32",
@@ -4823,7 +4824,9 @@ def VCVTxs2fd : N2VCvtD<0, 1, 0b1110, 0, 1, "vcvt", "f32.s32",
                         v2f32, v2i32, int_arm_neon_vcvtfxs2fp>;
 def VCVTxu2fd : N2VCvtD<1, 1, 0b1110, 0, 1, "vcvt", "f32.u32",
                         v2f32, v2i32, int_arm_neon_vcvtfxu2fp>;
+}
 
+let DecoderMethod = "DecodeVCVTQ" in {
 def VCVTf2xsq : N2VCvtQ<0, 1, 0b1111, 0, 1, "vcvt", "s32.f32",
                         v4i32, v4f32, int_arm_neon_vcvtfp2fxs>;
 def VCVTf2xuq : N2VCvtQ<1, 1, 0b1111, 0, 1, "vcvt", "u32.f32",
@@ -4832,6 +4835,7 @@ def VCVTxs2fq : N2VCvtQ<0, 1, 0b1110, 0, 1, "vcvt", "f32.s32",
                         v4f32, v4i32, int_arm_neon_vcvtfxs2fp>;
 def VCVTxu2fq : N2VCvtQ<1, 1, 0b1110, 0, 1, "vcvt", "f32.u32",
                         v4f32, v4i32, int_arm_neon_vcvtfxu2fp>;
+}
 
 //   VCVT     : Vector Convert Between Half-Precision and Single-Precision.
 def  VCVTf2h  : N2VNInt<0b11, 0b11, 0b01, 0b10, 0b01100, 0, 0,
diff --git a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index 0b9b5d0..65e2d04 100644
--- a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -179,8 +179,6 @@ static DecodeStatus DecodeAddrMode7Operand(llvm::MCInst &Inst, unsigned Val,
                                uint64_t Address, const void *Decoder);
 static DecodeStatus DecodeBranchImmInstruction(llvm::MCInst &Inst,unsigned Insn,
                                uint64_t Address, const void *Decoder);
-static DecodeStatus DecodeVCVTImmOperand(llvm::MCInst &Inst, unsigned Val,
-                               uint64_t Address, const void *Decoder);
 static DecodeStatus DecodeAddrMode6Operand(llvm::MCInst &Inst, unsigned Val,
                                uint64_t Address, const void *Decoder);
 static DecodeStatus DecodeVLDInstruction(llvm::MCInst &Inst, unsigned Val,
@@ -251,6 +249,11 @@ static DecodeStatus DecodeVMOVRRS(llvm::MCInst &Inst, unsigned Insn,
                                uint64_t Address, const void *Decoder);
 static DecodeStatus DecodeSwap(llvm::MCInst &Inst, unsigned Insn,
                                uint64_t Address, const void *Decoder);
+static DecodeStatus DecodeVCVTD(llvm::MCInst &Inst, unsigned Insn,
+                                uint64_t Address, const void *Decoder);
+static DecodeStatus DecodeVCVTQ(llvm::MCInst &Inst, unsigned Insn,
+                                uint64_t Address, const void *Decoder);
+
 
 static DecodeStatus DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
                                uint64_t Address, const void *Decoder);
@@ -1921,12 +1924,6 @@ DecodeBranchImmInstruction(llvm::MCInst &Inst, unsigned Insn,
 }
 
 
-static DecodeStatus DecodeVCVTImmOperand(llvm::MCInst &Inst, unsigned Val,
-                                 uint64_t Address, const void *Decoder) {
-  Inst.addOperand(MCOperand::CreateImm(64 - Val));
-  return MCDisassembler::Success;
-}
-
 static DecodeStatus DecodeAddrMode6Operand(llvm::MCInst &Inst, unsigned Val,
                                    uint64_t Address, const void *Decoder) {
   DecodeStatus S = MCDisassembler::Success;
@@ -4085,3 +4082,60 @@ static DecodeStatus DecodeSwap(llvm::MCInst &Inst, unsigned Insn,
 
   return S;
 }
+
+static DecodeStatus DecodeVCVTD(llvm::MCInst &Inst, unsigned Insn,
+                                uint64_t Address, const void *Decoder) {
+  unsigned Vd = (fieldFromInstruction32(Insn, 12, 4) << 0);
+  Vd |= (fieldFromInstruction32(Insn, 22, 1) << 4);
+  unsigned Vm = (fieldFromInstruction32(Insn, 0, 4) << 0);
+  Vm |= (fieldFromInstruction32(Insn, 5, 1) << 4);
+  unsigned imm = fieldFromInstruction32(Insn, 16, 6);
+  unsigned cmode = fieldFromInstruction32(Insn, 8, 4);
+
+  DecodeStatus S = MCDisassembler::Success;
+
+  // VMOVv2f32 is ambiguous with these decodings.
+  if (!(imm & 0x38 && cmode == 0xF)) {
+    Inst.setOpcode(ARM::VMOVv2f32);
+    return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
+  }
+
+  if (!(imm & 0x20)) Check(S, MCDisassembler::SoftFail);
+
+  if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
+    return MCDisassembler::Fail;
+  if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
+    return MCDisassembler::Fail;
+  Inst.addOperand(MCOperand::CreateImm(64 - imm));
+
+  return S;
+}
+
+static DecodeStatus DecodeVCVTQ(llvm::MCInst &Inst, unsigned Insn,
+                                uint64_t Address, const void *Decoder) {
+  unsigned Vd = (fieldFromInstruction32(Insn, 12, 4) << 0);
+  Vd |= (fieldFromInstruction32(Insn, 22, 1) << 4);
+  unsigned Vm = (fieldFromInstruction32(Insn, 0, 4) << 0);
+  Vm |= (fieldFromInstruction32(Insn, 5, 1) << 4);
+  unsigned imm = fieldFromInstruction32(Insn, 16, 6);
+  unsigned cmode = fieldFromInstruction32(Insn, 8, 4);
+
+  DecodeStatus S = MCDisassembler::Success;
+
+  // VMOVv4f32 is ambiguous with these decodings.
+  if (!(imm & 0x38) && cmode == 0xF) {
+    Inst.setOpcode(ARM::VMOVv4f32);
+    return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
+  }
+
+  if (!(imm & 0x20)) Check(S, MCDisassembler::SoftFail);
+
+  if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
+    return MCDisassembler::Fail;
+  if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
+    return MCDisassembler::Fail;
+  Inst.addOperand(MCOperand::CreateImm(64 - imm));
+
+  return S;
+}
+