diff --git a/compiler/utils/x86/assembler_x86.cc b/compiler/utils/x86/assembler_x86.cc
index fa85ada..44efc65 100644
--- a/compiler/utils/x86/assembler_x86.cc
+++ b/compiler/utils/x86/assembler_x86.cc
@@ -1515,6 +1515,14 @@
 }
 
 
+void X86Assembler::repe_cmpsw() {
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  EmitUint8(0x66);
+  EmitUint8(0xF3);
+  EmitUint8(0xA7);
+}
+
+
 X86Assembler* X86Assembler::lock() {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitUint8(0xF0);
diff --git a/compiler/utils/x86/assembler_x86.h b/compiler/utils/x86/assembler_x86.h
index d1b4e1d..e2abcde 100644
--- a/compiler/utils/x86/assembler_x86.h
+++ b/compiler/utils/x86/assembler_x86.h
@@ -465,6 +465,7 @@
   void jmp(Label* label);
 
   void repne_scasw();
+  void repe_cmpsw();
 
   X86Assembler* lock();
   void cmpxchgl(const Address& address, Register reg);
diff --git a/compiler/utils/x86/assembler_x86_test.cc b/compiler/utils/x86/assembler_x86_test.cc
index aacc57b..0e8c4ae 100644
--- a/compiler/utils/x86/assembler_x86_test.cc
+++ b/compiler/utils/x86/assembler_x86_test.cc
@@ -196,4 +196,10 @@
   DriverStr(expected, "Repnescasw");
 }
 
+TEST_F(AssemblerX86Test, Repecmpsw) {
+  GetAssembler()->repe_cmpsw();
+  const char* expected = "repe cmpsw\n";
+  DriverStr(expected, "Repecmpsw");
+}
+
 }  // namespace art
diff --git a/compiler/utils/x86_64/assembler_x86_64.cc b/compiler/utils/x86_64/assembler_x86_64.cc
index f35f51c..93c90db 100644
--- a/compiler/utils/x86_64/assembler_x86_64.cc
+++ b/compiler/utils/x86_64/assembler_x86_64.cc
@@ -2073,6 +2073,14 @@
 }
 
 
+void X86_64Assembler::repe_cmpsw() {
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  EmitUint8(0x66);
+  EmitUint8(0xF3);
+  EmitUint8(0xA7);
+}
+
+
 void X86_64Assembler::LoadDoubleConstant(XmmRegister dst, double value) {
   // TODO: Need to have a code constants table.
   int64_t constant = bit_cast<int64_t, double>(value);
diff --git a/compiler/utils/x86_64/assembler_x86_64.h b/compiler/utils/x86_64/assembler_x86_64.h
index 61ffeab..0cd3197 100644
--- a/compiler/utils/x86_64/assembler_x86_64.h
+++ b/compiler/utils/x86_64/assembler_x86_64.h
@@ -603,6 +603,7 @@
   void bswapq(CpuRegister dst);
 
   void repne_scasw();
+  void repe_cmpsw();
 
   //
   // Macros for High-level operations.
diff --git a/compiler/utils/x86_64/assembler_x86_64_test.cc b/compiler/utils/x86_64/assembler_x86_64_test.cc
index 6da5c35..422138c 100644
--- a/compiler/utils/x86_64/assembler_x86_64_test.cc
+++ b/compiler/utils/x86_64/assembler_x86_64_test.cc
@@ -1263,4 +1263,10 @@
   DriverStr(expected, "Repnescasw");
 }
 
+TEST_F(AssemblerX86_64Test, Repecmpsw) {
+  GetAssembler()->repe_cmpsw();
+  const char* expected = "repe cmpsw\n";
+  DriverStr(expected, "Repecmpsw");
+}
+
 }  // namespace art