[mips][microMIPS] Implement BEQZ16 and BNEZ16 instructions

[jkolek]

Summary

Implement microMIPS branch instructions BEQZ16 and BNEZ16.

[jkolek]

Added test file 'test/MC/Mips/micromips-branch7.s'.

[sstankovic]

lib/Target/Mips/AsmParser/MipsAsmParser.cpp

1078

I think you can use here "if (Offset.getImm() % 2 != 0)" instead of a call to OffsetToAlignment.

lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp

241

You can put fixup_MICROMIPS_PC7_S1 on the previous line - it's within the 80 columns limit.

lib/Target/Mips/MicroMipsInstrInfo.td

299

Note that MipsLongBranch has to be fixed for begz16 and bnez16, because it currently assumes that all branches have 16-bit offsets, and will produce wrong code if branches whose allowed offsets are [-64, ..., 63] are present. If long branch for begz16 and bnez16 (when it's implemented) doesn't clobber AT, "let Defs = [AT]" won't be needed. (You might add a TODO comment for all this in MipsLongBranch.cpp or here).

[jkolek]

Implemented decoder method DecodeBranchTarget7MM() and added disassembler tests.

[sstankovic]

lib/Target/Mips/AsmParser/MipsAsmParser.cpp

1219

You should use 8 instead of 7.

lib/Target/Mips/MicroMipsInstrInfo.td

423

MipsLongBranch.cpp file is better place for this comment. Also, I was wrong in the previous review comment - allowed offsets for beqz16 and bnez16 are [-128, -126, ..., 126]

[sstankovic]

LGTM

lib/Target/Mips/AsmParser/MipsAsmParser.cpp

bool isCOP2AsmReg() const {
     return isRegIdx() && RegIdx.Kind & RegKind_COP2 && RegIdx.Index <= 31;
   }
   bool isCOP3AsmReg() const {
     return isRegIdx() && RegIdx.Kind & RegKind_COP3 && RegIdx.Index <= 31;
   }
   bool isMSA128AsmReg() const {
     return isRegIdx() && RegIdx.Kind & RegKind_MSA128 && RegIdx.Index <= 31;
   }
   bool isMSACtrlAsmReg() const {
     return isRegIdx() && RegIdx.Kind & RegKind_MSACtrl && RegIdx.Index <= 7;
   }
 
   /// getStartLoc - Get the location of the first token of this operand.
   SMLoc getStartLoc() const override { return StartLoc; }
   /// getEndLoc - Get the location of the last token of this operand.
   SMLoc getEndLoc() const override { return EndLoc; }
 
case Mips::BC1T_MM:
       if (!Offset.isImm())
         break; // We'll deal with this situation later on when applying fixups.
       if (!isIntN(inMicroMipsMode() ? 17 : 18, Offset.getImm()))
         return Error(IDLoc, "branch target out of range");
       if (OffsetToAlignment(Offset.getImm(),
                             1LL << (inMicroMipsMode() ? 1 : 2)))
         return Error(IDLoc, "branch to misaligned address");
       break;
+    case Mips::BEQZ16_MM:
+    case Mips::BNEZ16_MM:
+      assert(MCID.getNumOperands() == 2 && "unexpected number of operands");
+      Offset = Inst.getOperand(1);
+      if (!Offset.isImm())
+        break; // We'll deal with this situation later on when applying fixups.
+      if (!isIntN(7, Offset.getImm()))
+        return Error(IDLoc, "branch target out of range");
+      if (OffsetToAlignment(Offset.getImm(), 2LL))
+        return Error(IDLoc, "branch to misaligned address");
+      break;
     }
   }
 
   // SSNOP is deprecated on MIPS32r6/MIPS64r6
   // We still accept it but it is a normal nop.
   if (hasMips32r6() && Inst.getOpcode() == Mips::SSNOP) {
     std::string ISA = hasMips64r6() ? "MIPS64r6" : "MIPS32r6";
     Warning(IDLoc, "ssnop is deprecated for " + ISA + " and is equivalent to a "

lib/Target/Mips/Disassembler/MipsDisassembler.cpp

static DecodeStatus DecodeBranchTarget21(MCInst &Inst,
                                          uint64_t Address,
                                          const void *Decoder);
 
 static DecodeStatus DecodeBranchTarget26(MCInst &Inst,
                                          unsigned Offset,
                                          uint64_t Address,
                                          const void *Decoder);
 
+// DecodeBranchTarget7MM - Decode microMIPS branch offset, which is
+// shifted left by 1 bit.
+static DecodeStatus DecodeBranchTarget7MM(MCInst &Inst,
+                                          unsigned Offset,
+                                          uint64_t Address,
+                                          const void *Decoder);
+
 // DecodeBranchTargetMM - Decode microMIPS branch offset, which is
 // shifted left by 1 bit.
 static DecodeStatus DecodeBranchTargetMM(MCInst &Inst,
                                          unsigned Offset,
                                          uint64_t Address,
                                          const void *Decoder);
 
 // DecodeJumpTargetMM - Decode microMIPS jump target, which is
static DecodeStatus DecodeBranchTarget26(MCInst &Inst,
                                          uint64_t Address,
                                          const void *Decoder) {
   int32_t BranchOffset = SignExtend32<26>(Offset) * 4;
 
   Inst.addOperand(MCOperand::CreateImm(BranchOffset));
   return MCDisassembler::Success;
 }
 
+static DecodeStatus DecodeBranchTarget7MM(MCInst &Inst,
+                                          unsigned Offset,
+                                          uint64_t Address,
+                                          const void *Decoder) {
+  int32_t BranchOffset = SignExtend32<7>(Offset) << 1;
+  Inst.addOperand(MCOperand::CreateImm(BranchOffset));
+  return MCDisassembler::Success;
+}
+
 static DecodeStatus DecodeBranchTargetMM(MCInst &Inst,
                                          unsigned Offset,
                                          uint64_t Address,
                                          const void *Decoder) {
   int32_t BranchOffset = SignExtend32<16>(Offset) * 2;
   Inst.addOperand(MCOperand::CreateImm(BranchOffset));
   return MCDisassembler::Success;
 }

lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp

case Mips::fixup_Mips_HIGHER:
     break;
   case Mips::fixup_Mips_HIGHEST:
     // Get the 4th 16-bits.
     Value = ((Value + 0x800080008000LL) >> 48) & 0xffff;
     break;
   case Mips::fixup_MICROMIPS_26_S1:
     Value >>= 1;
     break;
+  case Mips::fixup_MICROMIPS_PC7_S1:
+    Value -= 4;
+    // Forcing a signed division because Value can be negative.
+    Value = (int64_t) Value / 2;
+    // We now check if Value can be encoded as a 7-bit signed immediate.
+    if (!isIntN(7, Value) && Ctx)
+      Ctx->FatalError(Fixup.getLoc(), "out of range PC7 fixup");
+    break;
   case Mips::fixup_MICROMIPS_PC16_S1:
     Value -= 4;
     // Forcing a signed division because Value can be negative.
     Value = (int64_t)Value / 2;
     // We now check if Value can be encoded as a 16-bit signed immediate.
     if (!isIntN(16, Value) && Ctx)
       Ctx->FatalError(Fixup.getLoc(), "out of range PC16 fixup");
     break;
const static MCFixupKindInfo LittleEndianInfos[Mips::NumTargetFixupKinds] = {
     { "fixup_MIPS_PC21_S2",      0,     21,  MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MIPS_PC26_S2",      0,     26,  MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MIPS_PCHI16",       0,     16,  MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MIPS_PCLO16",       0,     16,  MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MICROMIPS_26_S1",   0,     26,   0 },
     { "fixup_MICROMIPS_HI16",    0,     16,   0 },
     { "fixup_MICROMIPS_LO16",    0,     16,   0 },
     { "fixup_MICROMIPS_GOT16",   0,     16,   0 },
+    { "fixup_MICROMIPS_PC7_S1",  0,      7,   MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MICROMIPS_PC16_S1", 0,     16,   MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MICROMIPS_CALL16",  0,     16,   0 },
     { "fixup_MICROMIPS_GOT_DISP",        0,     16,   0 },
     { "fixup_MICROMIPS_GOT_PAGE",        0,     16,   0 },
     { "fixup_MICROMIPS_GOT_OFST",        0,     16,   0 },
     { "fixup_MICROMIPS_TLS_GD",          0,     16,   0 },
     { "fixup_MICROMIPS_TLS_LDM",         0,     16,   0 },
     { "fixup_MICROMIPS_TLS_DTPREL_HI16", 0,     16,   0 },
const static MCFixupKindInfo BigEndianInfos[Mips::NumTargetFixupKinds] = {
     { "fixup_MIPS_PC21_S2",     11,     21,  MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MIPS_PC26_S2",      6,     26,  MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MIPS_PCHI16",      16,     16,  MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MIPS_PCLO16",      16,     16,  MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MICROMIPS_26_S1",   6,     26,   0 },
     { "fixup_MICROMIPS_HI16",   16,     16,   0 },
     { "fixup_MICROMIPS_LO16",   16,     16,   0 },
     { "fixup_MICROMIPS_GOT16",  16,     16,   0 },
+    { "fixup_MICROMIPS_PC7_S1",  9,      7,   MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MICROMIPS_PC16_S1",16,     16,   MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MICROMIPS_CALL16", 16,     16,   0 },
     { "fixup_MICROMIPS_GOT_DISP",        16,     16,   0 },
     { "fixup_MICROMIPS_GOT_PAGE",        16,     16,   0 },
     { "fixup_MICROMIPS_GOT_OFST",        16,     16,   0 },
     { "fixup_MICROMIPS_TLS_GD",          16,     16,   0 },
     { "fixup_MICROMIPS_TLS_LDM",         16,     16,   0 },
     { "fixup_MICROMIPS_TLS_DTPREL_HI16", 16,     16,   0 },

lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp

case Mips::fixup_MICROMIPS_HI16:
     Type = ELF::R_MICROMIPS_HI16;
     break;
   case Mips::fixup_MICROMIPS_LO16:
     Type = ELF::R_MICROMIPS_LO16;
     break;
   case Mips::fixup_MICROMIPS_GOT16:
     Type = ELF::R_MICROMIPS_GOT16;
     break;
+  case Mips::fixup_MICROMIPS_PC7_S1:
+    Type = ELF::R_MICROMIPS_PC7_S1;
+    break;
   case Mips::fixup_MICROMIPS_PC16_S1:
     Type = ELF::R_MICROMIPS_PC16_S1;
     break;
   case Mips::fixup_MICROMIPS_CALL16:
     Type = ELF::R_MICROMIPS_CALL16;
     break;
   case Mips::fixup_MICROMIPS_GOT_DISP:
     Type = ELF::R_MICROMIPS_GOT_DISP;

lib/Target/Mips/MCTargetDesc/MipsFixupKinds.h

enum Fixups {
     fixup_MICROMIPS_HI16,
 
     // resulting in - R_MICROMIPS_LO16
     fixup_MICROMIPS_LO16,
 
     // resulting in - R_MICROMIPS_GOT16
     fixup_MICROMIPS_GOT16,
 
+    // resulting in - R_MICROMIPS_PC7_S1
+    fixup_MICROMIPS_PC7_S1,
+
     // resulting in - R_MICROMIPS_PC16_S1
     fixup_MICROMIPS_PC16_S1,
 
     // resulting in - R_MICROMIPS_CALL16
     fixup_MICROMIPS_CALL16,
 
     // resulting in - R_MICROMIPS_GOT_DISP
     fixup_MICROMIPS_GOT_DISP,

lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.h

public:
 
   // getBranchTargetOpValue - Return binary encoding of the branch
   // target operand. If the machine operand requires relocation,
   // record the relocation and return zero.
   unsigned getBranchTargetOpValue(const MCInst &MI, unsigned OpNo,
                                   SmallVectorImpl<MCFixup> &Fixups,
                                   const MCSubtargetInfo &STI) const;
 
+  // getBranchTarget7OpValue - Return binary encoding of the microMIPS branch
+  // target operand. If the machine operand requires relocation,
+  // record the relocation and return zero.
+  unsigned getBranchTarget7OpValueMM(const MCInst &MI, unsigned OpNo,
+                                     SmallVectorImpl<MCFixup> &Fixups,
+                                     const MCSubtargetInfo &STI) const;
+
   // getBranchTargetOpValue - Return binary encoding of the microMIPS branch
   // target operand. If the machine operand requires relocation,
   // record the relocation and return zero.
   unsigned getBranchTargetOpValueMM(const MCInst &MI, unsigned OpNo,
                                     SmallVectorImpl<MCFixup> &Fixups,
                                     const MCSubtargetInfo &STI) const;
 
   // getBranchTarget21OpValue - Return binary encoding of the branch

lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp

assert(MO.isExpr() &&
          "getBranchTargetOpValue expects only expressions or immediates");
 
   const MCExpr *Expr = MO.getExpr();
   Fixups.push_back(MCFixup::Create(0, Expr,
                                    MCFixupKind(Mips::fixup_Mips_PC16)));
   return 0;
 }
 
+/// getBranchTarget7OpValueMM - Return binary encoding of the microMIPS branch
+/// target operand. If the machine operand requires relocation,
+/// record the relocation and return zero.
+unsigned MipsMCCodeEmitter::
+getBranchTarget7OpValueMM(const MCInst &MI, unsigned OpNo,
+                          SmallVectorImpl<MCFixup> &Fixups,
+                          const MCSubtargetInfo &STI) const {
+
+  const MCOperand &MO = MI.getOperand(OpNo);
+
+  // If the destination is an immediate, divide by 2.
+  if (MO.isImm()) return MO.getImm() >> 1;
+
+  assert(MO.isExpr() &&
+         "getBranchTargetOpValueMM expects only expressions or immediates");
+
+  const MCExpr *Expr = MO.getExpr();
+  Fixups.push_back(MCFixup::Create(0, Expr,
+                                   MCFixupKind(Mips::fixup_MICROMIPS_PC7_S1)));
+  return 0;
+}
+
 /// getBranchTargetOpValue - Return binary encoding of the microMIPS branch
 /// target operand. If the machine operand requires relocation,
 /// record the relocation and return zero.
 unsigned MipsMCCodeEmitter::
 getBranchTargetOpValueMM(const MCInst &MI, unsigned OpNo,
                          SmallVectorImpl<MCFixup> &Fixups,
                          const MCSubtargetInfo &STI) const {
 

lib/Target/Mips/MicroMipsInstrFormats.td

class BRKSDBBP16_FM_MM<bits<6> op> {
   bits<4> code_;
   bits<16> Inst;
 
   let Inst{15-10} = 0x11;
   let Inst{9-4}   = op;
   let Inst{3-0}   = code_;
 }
 
+class BEQNEZ_FM_MM16<bits<6> op> {
+  bits<3> rs;
+  bits<7> offset;
+
+  bits<16> Inst;
+
+  let Inst{15-10} = op;
+  let Inst{9-7}   = rs;
+  let Inst{6-0}   = offset;
+}
+
 //===----------------------------------------------------------------------===//
 // MicroMIPS 32-bit Instruction Formats
 //===----------------------------------------------------------------------===//
 
 class MMArch {
   string Arch = "micromips";
   list<dag> Pattern = [];
 }

lib/Target/Mips/MicroMipsInstrInfo.td

 def jmptarget_mm : Operand<OtherVT> {
   let EncoderMethod = "getJumpTargetOpValueMM";
 }
 
 def calltarget_mm : Operand<iPTR> {
   let EncoderMethod = "getJumpTargetOpValueMM";
 }
 
+def brtarget7_mm : Operand<OtherVT> {
+  let EncoderMethod = "getBranchTarget7OpValueMM";
+  let OperandType   = "OPERAND_PCREL";
+  let DecoderMethod = "DecodeBranchTarget7MM";
+  let ParserMatchClass = MipsJumpTargetAsmOperand;
+}
+
 def brtarget_mm : Operand<OtherVT> {
   let EncoderMethod = "getBranchTargetOpValueMM";
   let OperandType   = "OPERAND_PCREL";
   let DecoderMethod = "DecodeBranchTargetMM";
 }
 
 def simm23_lsl2 : Operand<i32> {
   let EncoderMethod = "getSimm23Lsl2Encoding";

 
 class StoreMM16<string opstr, DAGOperand RTOpnd, DAGOperand RO,
                 SDPatternOperator OpNode, InstrItinClass Itin,
                 Operand MemOpnd> :
   MicroMipsInst16<(outs), (ins RTOpnd:$rt, MemOpnd:$addr),
                   !strconcat(opstr, "\t$rt, $addr"), [], Itin, FrmI> {
   let DecoderMethod = "DecodeMemMMImm4";
   let mayStore = 1;
 }
 
 class LoadSPMM16<string opstr, DAGOperand RO, InstrItinClass Itin,
                  Operand MemOpnd> :
   MicroMipsInst16<(outs RO:$rt), (ins MemOpnd:$offset),
                   !strconcat(opstr, "\t$rt, $offset"), [], Itin, FrmI> {
   let DecoderMethod = "DecodeMemMMSPImm5Lsl2";
   let canFoldAsLoad = 1;
   let mayLoad = 1;

 }
 
 // Break16 and Sdbbp16
 class BrkSdbbp16MM<string opstr> :
   MicroMipsInst16<(outs), (ins uimm4:$code_),
                   !strconcat(opstr, "\t$code_"),
                   [], NoItinerary, FrmOther>;
 
+// TODO: MipsLongBranch has to be fixed for begz16 and bnez16, because it
+// currently assumes that all branches have 16-bit offsets, and will produce
+// wrong code if branches whose allowed offsets are [-64, ..., 63] are present.
+class CBranchZeroMM<string opstr, DAGOperand opnd, RegisterOperand RO> :
+  MicroMipsInst16<(outs), (ins RO:$rs, opnd:$offset),
+                  !strconcat(opstr, "\t$rs, $offset"), [], IIBranch, FrmI> {
+  let isBranch = 1;
+  let isTerminator = 1;
+  let hasDelaySlot = 1;
+  let Defs = [AT];
+}
+
 // MicroMIPS Jump and Link (Call) - Short Delay Slot
 let isCall = 1, hasDelaySlot = 1, Defs = [RA] in {
   class JumpLinkMM<string opstr, DAGOperand opnd> :
     InstSE<(outs), (ins opnd:$target), !strconcat(opstr, "\t$target"),
            [], IIBranch, FrmJ, opstr> {
     let DecoderMethod = "DecodeJumpTargetMM";
   }
 

 def MOVE16_MM : MoveMM16<"move", GPR32Opnd>, MOVE_FM_MM16<0x03>;
 def LI16_MM : LoadImmMM16<"li16", li_simm7, GPRMM16Opnd>, LI_FM_MM16,
               IsAsCheapAsAMove;
 def JALR16_MM : JumpLinkRegMM16<"jalr", GPR32Opnd>, JALR_FM_MM16<0x0e>;
 def JALRS16_MM : JumpLinkRegSMM16<"jalrs16", GPR32Opnd>, JALR_FM_MM16<0x0f>;
 def JRC16_MM : JumpRegCMM16<"jrc", GPR32Opnd>, JALR_FM_MM16<0x0d>;
 def JRADDIUSP : JumpRAddiuStackMM16, JRADDIUSP_FM_MM16<0x18>;
 def JR16_MM : JumpRegMM16<"jr16", GPR32Opnd>, JALR_FM_MM16<0x0c>;
+def BEQZ16_MM : CBranchZeroMM<"beqz16", brtarget7_mm, GPRMM16Opnd>,
+                BEQNEZ_FM_MM16<0x23>;
+def BNEZ16_MM : CBranchZeroMM<"bnez16", brtarget7_mm, GPRMM16Opnd>,
+                BEQNEZ_FM_MM16<0x2b>;
 def BREAK16_MM : BrkSdbbp16MM<"break16">, BRKSDBBP16_FM_MM<0x28>;
 def SDBBP16_MM : BrkSdbbp16MM<"sdbbp16">, BRKSDBBP16_FM_MM<0x2C>;
 
 class WaitMM<string opstr> :
   InstSE<(outs), (ins uimm10:$code_), !strconcat(opstr, "\t$code_"), [],
          NoItinerary, FrmOther, opstr>;
 
 let DecoderNamespace = "MicroMips", Predicates = [InMicroMips] in {

test/MC/Disassembler/Mips/micromips.txt

 # CHECK: lw $3, 32($sp)
 0x48 0x68
 
 # CHECK: sw $4, 124($sp)
 0xc8 0x9f
 
 # CHECK: lw $3, 32($gp)
 0x65 0x88
+
+# CHECK: beqz16 $6, 20
+0x8f 0x0a
+
+# CHECK: bnez16 $6, 20
+0xaf 0x0a

test/MC/Disassembler/Mips/micromips_le.txt

 # CHECK: lw $3, 32($sp)
 0x68 0x48
 
 # CHECK: sw $4, 124($sp)
 0x9f 0xc8
 
 # CHECK: lw $3, 32($gp)
 0x88 0x65
+
+# CHECK: beqz16 $6, 20
+0x0a 0x8f
+
+# CHECK: bnez16 $6, 20
+0x0a 0xaf

test/MC/Mips/micromips-16-bit-instructions.s

 # CHECK-EL: move    $25, $1         # encoding: [0x21,0x0f]
 # CHECK-EL: jrc     $9              # encoding: [0xa9,0x45]
 # CHECK-NEXT: jalr    $9            # encoding: [0xc9,0x45]
 # CHECK-EL: jraddiusp 20            # encoding: [0x05,0x47]
 # CHECK-NEXT: jalrs16 $9            # encoding: [0xe9,0x45]
 # CHECK-EL: nop                     # encoding: [0x00,0x0c]
 # CHECK-EL: jr16    $9              # encoding: [0x89,0x45]
 # CHECK-EL: nop                     # encoding: [0x00,0x00,0x00,0x00]
+# CHECK-EL: beqz16 $6, 20           # encoding: [0x0a,0x8f]
+# CHECK-EL: nop                     # encoding: [0x00,0x00,0x00,0x00]
+# CHECK-EL: bnez16 $6, 20           # encoding: [0x0a,0xaf]
+# CHECK-EL: nop                     # encoding: [0x00,0x00,0x00,0x00]
 # CHECK-EL: break16 8               # encoding: [0x88,0x46]
 # CHECK-EL: sdbbp16 14              # encoding: [0xce,0x46]
 #------------------------------------------------------------------------------
 # Big endian
 #------------------------------------------------------------------------------
 # CHECK-EB: addu16  $6, $17, $4     # encoding: [0x07,0x42]
 # CHECK-EB: subu16  $5, $16, $3     # encoding: [0x06,0xb1]
 # CHECK-EB: andi16  $16, $2, 31     # encoding: [0x2c,0x29]

 # CHECK-EB: move    $25, $1         # encoding: [0x0f,0x21]
 # CHECK-EB: jrc     $9              # encoding: [0x45,0xa9]
 # CHECK-NEXT: jalr    $9            # encoding: [0x45,0xc9]
 # CHECK-EB: jraddiusp 20            # encoding: [0x47,0x05]
 # CHECK-NEXT: jalrs16 $9            # encoding: [0x45,0xe9]
 # CHECK-EB: nop                     # encoding: [0x0c,0x00]
 # CHECK-EB: jr16    $9              # encoding: [0x45,0x89]
 # CHECK-EB: nop                     # encoding: [0x00,0x00,0x00,0x00]
+# CHECK-EB: beqz16 $6, 20           # encoding: [0x8f,0x0a]
+# CHECK-EB: nop                     # encoding: [0x00,0x00,0x00,0x00]
+# CHECK-EB: bnez16 $6, 20           # encoding: [0xaf,0x0a]
+# CHECK-EB: nop                     # encoding: [0x00,0x00,0x00,0x00]
 # CHECK-EB: break16 8               # encoding: [0x46,0x88]
 # CHECK-EB: sdbbp16 14              # encoding: [0x46,0xce]
 
     addu16  $6, $17, $4
     subu16  $5, $16, $3
     andi16  $16, $2, 31
     and16   $16, $2
     not16   $17, $3
# CHECK-EB: sdbbp16 14              # encoding: [0x46,0xce]
     mfhi    $9
     mflo    $9
     move    $25, $1
     jrc     $9
     jalr    $9
     jraddiusp 20
     jalrs16 $9
     jr16    $9
+    beqz16 $6, 20
+    bnez16 $6, 20
     break16 8
     sdbbp16 14

test/MC/Mips/micromips-bad-branches.s

 # CHECK:        bc1t $fcc0, -65535
 # CHECK: error: branch target out of range
 # CHECK:        bc1t $fcc0, -65537
 # CHECK: error: branch to misaligned address
 # CHECK:        bc1t $fcc0, 65535
 # CHECK: error: branch target out of range
 # CHECK:        bc1t $fcc0, 65536
 
+# CHECK: error: branch to misaligned address
+# CHECK:        beqz16 $6, 31
+# CHECK: error: branch target out of range
+# CHECK:        beqz16 $6, 64
+
         b -65535
         b -65536
         b -65537
         b 65534
         b 65535
         b 65536
 
         beq $1, $1, -65535
# CHECK:        beqz16 $6, 64
         bc1t 65536
 
         bc1t $fcc0, -65535
         bc1t $fcc0, -65536
         bc1t $fcc0, -65537
         bc1t $fcc0, 65534
         bc1t $fcc0, 65535
         bc1t $fcc0, 65536
+
+        beqz16 $6, 31
+        beqz16 $6, 64

test/MC/Mips/micromips-branch7.s

+# RUN: llvm-mc %s -triple=mipsel-unknown-linux -show-encoding \
+# RUN: -mattr=micromips | FileCheck %s -check-prefix=CHECK-FIXUP
+# RUN: llvm-mc %s -filetype=obj -triple=mipsel-unknown-linux \
+# RUN: -mattr=micromips | llvm-readobj -r \
+# RUN: | FileCheck %s -check-prefix=CHECK-ELF
+#------------------------------------------------------------------------------
+# Check that the assembler can handle the documented syntax
+# for relocations.
+#------------------------------------------------------------------------------
+# CHECK-FIXUP: beqz16 $6, bar  # encoding: [0b0AAAAAAA,0x8f]
+# CHECK-FIXUP:                 #   fixup A - offset: 0,
+# CHECK-FIXUP:                     value: bar, kind: fixup_MICROMIPS_PC7_S1
+# CHECK-FIXUP: nop             # encoding: [0x00,0x00,0x00,0x00]
+# CHECK-FIXUP: bnez16 $6, bar  # encoding: [0b0AAAAAAA,0xaf]
+# CHECK-FIXUP:                 #   fixup A - offset: 0,
+# CHECK-FIXUP:                     value: bar, kind: fixup_MICROMIPS_PC7_S1
+# CHECK-FIXUP: nop             # encoding: [0x00,0x00,0x00,0x00]
+#------------------------------------------------------------------------------
+# Check that the appropriate relocations were created.
+#------------------------------------------------------------------------------
+# CHECK-ELF: Relocations [
+# CHECK-ELF:     0x{{[0-9,A-F]+}} R_MICROMIPS_PC7_S1
+# CHECK-ELF:     0x{{[0-9,A-F]+}} R_MICROMIPS_PC7_S1
+# CHECK-ELF: ]
+
+  beqz16 $6, bar
+  bnez16 $6, bar

test/MC/Mips/micromips-invalid.s

# RUN: FileCheck %s < %t1
   lbu16 $16, 8($9)  # CHECK: :[[@LINE]]:{{[0-9]+}}: error: invalid operand for instruction
   lhu16 $16, 4($9)  # CHECK: :[[@LINE]]:{{[0-9]+}}: error: invalid operand for instruction
   lw16  $17, 8($10) # CHECK: :[[@LINE]]:{{[0-9]+}}: error: invalid operand for instruction
   sb16  $7, 4($9)   # CHECK: :[[@LINE]]:{{[0-9]+}}: error: invalid operand for instruction
   sh16  $7, 8($9)   # CHECK: :[[@LINE]]:{{[0-9]+}}: error: invalid operand for instruction
   sw16  $7, 4($10)  # CHECK: :[[@LINE]]:{{[0-9]+}}: error: invalid operand for instruction
   cache 256, 8($5)  # CHECK: :[[@LINE]]:{{[0-9]+}}: error: immediate operand value out of range
   pref 256, 8($5)   # CHECK: :[[@LINE]]:{{[0-9]+}}: error: immediate operand value out of range
+  beqz16 $9, 20 # CHECK: :[[@LINE]]:{{[0-9]+}}: error: invalid operand for instruction
+  bnez16 $9, 20 # CHECK: :[[@LINE]]:{{[0-9]+}}: error: invalid operand for instruction