Index: lib/Target/Mips/MicroMips32r6InstrFormats.td
===================================================================
--- lib/Target/Mips/MicroMips32r6InstrFormats.td
+++ lib/Target/Mips/MicroMips32r6InstrFormats.td
@@ -272,3 +272,18 @@
   let Inst{15-6}  = funct;
   let Inst{5-0}   = 0x3c;
 }
+
+class SHIFT_MMR6_ENC<string instr_asm, bits<10> funct, bit rotate> : MMR6Arch<instr_asm> {
+  bits<5> rd;
+  bits<5> rt;
+  bits<5> shamt;
+
+  bits<32> Inst;
+
+  let Inst{31-26} = 0;
+  let Inst{25-21} = rd;
+  let Inst{20-16} = rt;
+  let Inst{15-11} = shamt;
+  let Inst{10}    = rotate;
+  let Inst{9-0}   = funct;
+}
Index: lib/Target/Mips/MicroMips32r6InstrInfo.td
===================================================================
--- lib/Target/Mips/MicroMips32r6InstrInfo.td
+++ lib/Target/Mips/MicroMips32r6InstrInfo.td
@@ -63,6 +63,7 @@
 class SEH_MMR6_ENC : SIGN_EXTEND_FM_MMR6<"seh", 0b0011101100>;
 class SELEQZ_MMR6_ENC : POOL32A_FM_MMR6<0b0101000000>;
 class SELNEZ_MMR6_ENC : POOL32A_FM_MMR6<0b0110000000>;
+class SLL_MMR6_ENC : SHIFT_MMR6_ENC<"sll", 0x00, 0b0>;
 class SUB_MMR6_ENC : ARITH_FM_MMR6<"sub", 0x190>;
 class SUBU_MMR6_ENC : ARITH_FM_MMR6<"subu", 0x1d0>;
 class XOR_MMR6_ENC : ARITH_FM_MMR6<"xor", 0x310>;
@@ -263,6 +264,7 @@
 
 class SELEQZ_MMR6_DESC : SELEQNE_Z_MMR6_DESC_BASE<"seleqz", GPR32Opnd>;
 class SELNEZ_MMR6_DESC : SELEQNE_Z_MMR6_DESC_BASE<"selnez", GPR32Opnd>;
+class SLL_MMR6_DESC : shift_rotate_imm<"sll", uimm5, GPR32Opnd, II_SLL>;
 class DIV_MMR6_DESC : ArithLogicR<"div", GPR32Opnd>;
 class DIVU_MMR6_DESC : ArithLogicR<"divu", GPR32Opnd>;
 class MOD_MMR6_DESC : ArithLogicR<"mod", GPR32Opnd>;
@@ -341,6 +343,7 @@
                   ISA_MICROMIPS32R6;
 def SELNEZ_MMR6 : R6MMR6Rel, SELNEZ_MMR6_ENC, SELNEZ_MMR6_DESC,
                   ISA_MICROMIPS32R6;
+def SLL_MMR6 : StdMMR6Rel, SLL_MMR6_DESC, SLL_MMR6_ENC, ISA_MICROMIPS32R6;
 def SUB_MMR6 : StdMMR6Rel, SUB_MMR6_DESC, SUB_MMR6_ENC, ISA_MICROMIPS32R6;
 def SUBU_MMR6 : StdMMR6Rel, SUBU_MMR6_DESC, SUBU_MMR6_ENC, ISA_MICROMIPS32R6;
 def XOR_MMR6 : StdMMR6Rel, XOR_MMR6_DESC, XOR_MMR6_ENC, ISA_MICROMIPS32R6;
@@ -354,3 +357,4 @@
 //===----------------------------------------------------------------------===//
 
 def : MipsInstAlias<"ei", (EI_MMR6 ZERO), 1>, ISA_MICROMIPS32R6;
+def : MipsInstAlias<"nop", (SLL_MMR6 ZERO, ZERO, 0), 1>, ISA_MICROMIPS32R6;
Index: lib/Target/Mips/MipsInstrInfo.td
===================================================================
--- lib/Target/Mips/MipsInstrInfo.td
+++ lib/Target/Mips/MipsInstrInfo.td
@@ -1611,7 +1611,9 @@
                     (ORi GPR32Opnd:$rs, GPR32Opnd:$rt, uimm16:$imm), 0>;
 def : MipsInstAlias<"or $rs, $imm",
                     (ORi GPR32Opnd:$rs, GPR32Opnd:$rs, uimm16:$imm), 0>;
+let AdditionalPredicates = [NotInMicroMips] in {
 def : MipsInstAlias<"nop", (SLL ZERO, ZERO, 0), 1>;
+}
 def : MipsInstAlias<"mfc0 $rt, $rd", (MFC0 GPR32Opnd:$rt, COP0Opnd:$rd, 0), 0>;
 def : MipsInstAlias<"mtc0 $rt, $rd", (MTC0 COP0Opnd:$rd, GPR32Opnd:$rt, 0), 0>;
 def : MipsInstAlias<"mfc2 $rt, $rd", (MFC2 GPR32Opnd:$rt, COP2Opnd:$rd, 0), 0>;
Index: test/MC/Disassembler/Mips/micromips32r6.txt
===================================================================
--- test/MC/Disassembler/Mips/micromips32r6.txt
+++ test/MC/Disassembler/Mips/micromips32r6.txt
@@ -84,6 +84,8 @@
 
 0x00 0xa4,0x18,0xd8 # CHECK: muhu $3, $4, $5
 
+0x00 0x00 0x00 0x00 # CHECK: nop
+
 0x00 0xa4 0x1a 0xd0 # CHECK: nor $3, $4, $5
 
 0x00,0xa4,0x1a,0x90 # CHECK: or $3, $4, $5
@@ -96,6 +98,8 @@
 
 0x00 0x83 0x11 0x80 # CHECK: selnez $2, $3, $4
 
+0x00 0x83 0x38 0x00 # CHECK: sll $4, $3, 7
+
 0x00 0xa4 0x19 0x90 # CHECK: sub $3, $4, $5
 
 0x00 0xa4 0x19 0xd0 # CHECK: subu $3, $4, $5
Index: test/MC/Mips/micromips32r6/valid.s
===================================================================
--- test/MC/Mips/micromips32r6/valid.s
+++ test/MC/Mips/micromips32r6/valid.s
@@ -44,6 +44,7 @@
   muh $3, $4, $5           # CHECK muh $3, $4, $5       # encoding: [0x00,0xa4,0x18,0x58]
   mulu $3, $4, $5          # CHECK mulu $3, $4, $5      # encoding: [0x00,0xa4,0x18,0x98]
   muhu $3, $4, $5          # CHECK muhu $3, $4, $5      # encoding: [0x00,0xa4,0x18,0xd8]
+  nop                      # CHECK: nop                 # encoding: [0x00,0x00,0x00,0x00]
   nor $3, $4, $5           # CHECK: nor $3, $4, $5      # encoding: [0x00,0xa4,0x1a,0xd0]
   or $3, $4, $5            # CHECK: or $3, $4, $5       # encoding: [0x00,0xa4,0x1a,0x90]
   ori $3, $4, 1234         # CHECK: ori $3, $4, 1234    # encoding: [0x50,0x64,0x04,0xd2]
@@ -52,6 +53,7 @@
   seh $3, $4               # CHECK: seh $3, $4          # encoding: [0x00,0x64,0x3b,0x3c]
   seleqz $2,$3,$4          # CHECK: seleqz $2, $3, $4   # encoding: [0x00,0x83,0x11,0x40]
   selnez $2,$3,$4          # CHECK: selnez $2, $3, $4   # encoding: [0x00,0x83,0x11,0x80]
+  sll $4, $3, 7            # CHECK: sll $4, $3, 7       # encoding: [0x00,0x83,0x38,0x00]
   sub $3, $4, $5           # CHECK: sub $3, $4, $5      # encoding: [0x00,0xa4,0x19,0x90]
   subu $3, $4, $5          # CHECK: subu $3, $4, $5     # encoding: [0x00,0xa4,0x19,0xd0]
   xor $3, $4, $5           # CHECK: xor $3, $4, $5      # encoding: [0x00,0xa4,0x1b,0x10]