diff --git a/llvm/lib/Target/Mips/MicroMips32r6InstrFormats.td b/llvm/lib/Target/Mips/MicroMips32r6InstrFormats.td
index 707e4da91dfa..7350b97731ba 100644
--- a/llvm/lib/Target/Mips/MicroMips32r6InstrFormats.td
+++ b/llvm/lib/Target/Mips/MicroMips32r6InstrFormats.td
@@ -71,6 +71,20 @@ class ADDI_FM_MMR6<string instr_asm, bits<6> op> : MMR6Arch<instr_asm> {
   let Inst{15-0}  = imm16;
 }
 
+class SIGN_EXTEND_FM_MMR6<string instr_asm, bits<10> funct>
+    : MMR6Arch<instr_asm> {
+  bits<5> rd;
+  bits<5> rt;
+
+  bits<32> Inst;
+
+  let Inst{31-26} = 0b000000;
+  let Inst{25-21} = rd;
+  let Inst{20-16} = rt;
+  let Inst{15-6}  = funct;
+  let Inst{5-0}   = 0b111100;
+}
+
 class PCREL19_FM_MMR6<bits<2> funct> : MipsR6Inst {
   bits<5> rt;
   bits<19> imm;
diff --git a/llvm/lib/Target/Mips/MicroMips32r6InstrInfo.td b/llvm/lib/Target/Mips/MicroMips32r6InstrInfo.td
index dd6848a8b95b..2259d5d77904 100644
--- a/llvm/lib/Target/Mips/MicroMips32r6InstrInfo.td
+++ b/llvm/lib/Target/Mips/MicroMips32r6InstrInfo.td
@@ -54,6 +54,8 @@ class NOR_MMR6_ENC : ARITH_FM_MMR6<"nor", 0x2d0>;
 class OR_MMR6_ENC : ARITH_FM_MMR6<"or", 0x290>;
 class ORI_MMR6_ENC : ADDI_FM_MMR6<"ori", 0x14>;
 class PREF_MMR6_ENC : CACHE_PREF_FM_MMR6<0b011000, 0b0010>;
+class SEB_MMR6_ENC : SIGN_EXTEND_FM_MMR6<"seb", 0b0010101100>;
+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 SUB_MMR6_ENC : ARITH_FM_MMR6<"sub", 0x190>;
@@ -204,6 +206,8 @@ class AUI_MMR6_DESC_BASE<string instr_asm, RegisterOperand GPROpnd>
 
 class AUI_MMR6_DESC : AUI_MMR6_DESC_BASE<"aui", GPR32Opnd>;
 
+class SEB_MMR6_DESC : SignExtInReg<"seb", i8, GPR32Opnd, II_SEB>;
+class SEH_MMR6_DESC : SignExtInReg<"seh", i16, GPR32Opnd, II_SEH>;
 class ALUIPC_MMR6_DESC_BASE<string instr_asm, RegisterOperand GPROpnd>
     : MMR6Arch<instr_asm> {
   dag OutOperandList = (outs GPROpnd:$rt);
@@ -312,6 +316,8 @@ def NOR_MMR6 : StdMMR6Rel, NOR_MMR6_DESC, NOR_MMR6_ENC, ISA_MICROMIPS32R6;
 def OR_MMR6 : StdMMR6Rel, OR_MMR6_DESC, OR_MMR6_ENC, ISA_MICROMIPS32R6;
 def ORI_MMR6 : StdMMR6Rel, ORI_MMR6_DESC, ORI_MMR6_ENC, ISA_MICROMIPS32R6;
 def PREF_MMR6 : R6MMR6Rel, PREF_MMR6_ENC, PREF_MMR6_DESC, ISA_MICROMIPS32R6;
+def SEB_MMR6 : StdMMR6Rel, SEB_MMR6_DESC, SEB_MMR6_ENC, ISA_MICROMIPS32R6;
+def SEH_MMR6 : StdMMR6Rel, SEH_MMR6_DESC, SEH_MMR6_ENC, ISA_MICROMIPS32R6;
 def SELEQZ_MMR6 : R6MMR6Rel, SELEQZ_MMR6_ENC, SELEQZ_MMR6_DESC,
                   ISA_MICROMIPS32R6;
 def SELNEZ_MMR6 : R6MMR6Rel, SELNEZ_MMR6_ENC, SELNEZ_MMR6_DESC,
diff --git a/llvm/lib/Target/Mips/MipsInstrInfo.td b/llvm/lib/Target/Mips/MipsInstrInfo.td
index 3e47914d58d6..58791cf2734a 100644
--- a/llvm/lib/Target/Mips/MipsInstrInfo.td
+++ b/llvm/lib/Target/Mips/MipsInstrInfo.td
@@ -1410,9 +1410,9 @@ def MFLO : MMRel, MoveFromLOHI<"mflo", GPR32Opnd, AC0>, MFLO_FM<0x12>,
 }
 
 /// Sign Ext In Register Instructions.
-def SEB : MMRel, SignExtInReg<"seb", i8, GPR32Opnd, II_SEB>,
+def SEB : MMRel, StdMMR6Rel, SignExtInReg<"seb", i8, GPR32Opnd, II_SEB>,
           SEB_FM<0x10, 0x20>, ISA_MIPS32R2;
-def SEH : MMRel, SignExtInReg<"seh", i16, GPR32Opnd, II_SEH>,
+def SEH : MMRel, StdMMR6Rel, SignExtInReg<"seh", i16, GPR32Opnd, II_SEH>,
           SEB_FM<0x18, 0x20>, ISA_MIPS32R2;
 
 /// Count Leading
diff --git a/llvm/test/MC/Disassembler/Mips/micromips32r6.txt b/llvm/test/MC/Disassembler/Mips/micromips32r6.txt
index 9418f58df360..dee6fbef4090 100644
--- a/llvm/test/MC/Disassembler/Mips/micromips32r6.txt
+++ b/llvm/test/MC/Disassembler/Mips/micromips32r6.txt
@@ -93,3 +93,7 @@
 
 0x70 0x64 0x04 0xd2 # CHECK: xori $3, $4, 1234
 
+0x00 0x64 0x2b 0x3c # CHECK: seb $3, $4
+
+0x00 0x64 0x3b 0x3c # CHECK: seh $3, $4
+
diff --git a/llvm/test/MC/Mips/micromips32r6/valid.s b/llvm/test/MC/Mips/micromips32r6/valid.s
index 325932a47bf8..f4e8eef8f23b 100644
--- a/llvm/test/MC/Mips/micromips32r6/valid.s
+++ b/llvm/test/MC/Mips/micromips32r6/valid.s
@@ -39,6 +39,8 @@
   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]
   pref 1, 8($5)            # CHECK: pref 1, 8($5)       # encoding: [0x60,0x25,0x20,0x08]
+  seb $3, $4               # CHECK: seb $3, $4          # encoding: [0x00,0x64,0x2b,0x3c]
+  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]
   sub $3, $4, $5           # CHECK: sub $3, $4, $5      # encoding: [0x00,0xa4,0x19,0x90]