diff --git a/include/clang/Basic/BuiltinsARM.def b/include/clang/Basic/BuiltinsARM.def
index 1f2f9a3840..9091ad4d75 100644
--- a/include/clang/Basic/BuiltinsARM.def
+++ b/include/clang/Basic/BuiltinsARM.def
@@ -85,6 +85,8 @@ BUILTIN(__builtin_arm_isb, "vUi", "nc")
 BUILTIN(__builtin_arm_prefetch, "vvC*UiUi", "nc")
 
 // MSVC
+LANGBUILTIN(__emit, "vIUiC", "", ALL_MS_LANGUAGES)
+
 LANGBUILTIN(__yield, "v", "", ALL_MS_LANGUAGES)
 LANGBUILTIN(__wfe, "v", "", ALL_MS_LANGUAGES)
 LANGBUILTIN(__wfi, "v", "", ALL_MS_LANGUAGES)
diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index 155545d4c9..fca60d50c5 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -20,7 +20,9 @@
 #include "clang/Basic/TargetBuiltins.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/CodeGen/CGFunctionInfo.h"
+#include "llvm/ADT/StringExtras.h"
 #include "llvm/IR/DataLayout.h"
+#include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/Intrinsics.h"
 
 using namespace clang;
@@ -3165,6 +3167,26 @@ Value *CodeGenFunction::EmitARMBuiltinExpr(unsigned BuiltinID,
   if (auto Hint = GetValueForARMHint(BuiltinID))
     return Hint;
 
+  if (BuiltinID == ARM::BI__emit) {
+    bool IsThumb = getTarget().getTriple().getArch() == llvm::Triple::thumb;
+    llvm::FunctionType *FTy =
+        llvm::FunctionType::get(VoidTy, /*Variadic=*/false);
+
+    APSInt Value;
+    if (!E->getArg(0)->EvaluateAsInt(Value, CGM.getContext()))
+      llvm_unreachable("Sema will ensure that the parameter is constant");
+
+    uint64_t ZExtValue = Value.zextOrTrunc(IsThumb ? 16 : 32).getZExtValue();
+
+    llvm::InlineAsm *Emit =
+        IsThumb ? InlineAsm::get(FTy, ".inst.n 0x" + utohexstr(ZExtValue), "",
+                                 /*SideEffects=*/true)
+                : InlineAsm::get(FTy, ".inst 0x" + utohexstr(ZExtValue), "",
+                                 /*SideEffects=*/true);
+
+    return Builder.CreateCall(Emit);
+  }
+
   if (BuiltinID == ARM::BI__builtin_arm_dbg) {
     Value *Option = EmitScalarExpr(E->getArg(0));
     return Builder.CreateCall(CGM.getIntrinsic(Intrinsic::arm_dbg), Option);
diff --git a/test/CodeGen/builtins-arm-msvc-compat-error.c b/test/CodeGen/builtins-arm-msvc-compat-error.c
new file mode 100644
index 0000000000..29469deb6a
--- /dev/null
+++ b/test/CodeGen/builtins-arm-msvc-compat-error.c
@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -triple thumbv7-windows -fms-extensions -verify %s
+
+void emit_error(unsigned int opcode) {
+  __emit(opcode); // expected-error {{argument to '__emit' must be a constant integer}}
+}
+
diff --git a/test/CodeGen/builtins-arm-msvc-compat-only.c b/test/CodeGen/builtins-arm-msvc-compat-only.c
new file mode 100644
index 0000000000..db82ca4066
--- /dev/null
+++ b/test/CodeGen/builtins-arm-msvc-compat-only.c
@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 -triple thumbv7-windows -fms-extensions -emit-llvm -o - %s \
+// RUN:     | FileCheck %s -check-prefix CHECK-MSVC
+// RUN: %clang_cc1 -triple armv7-eabi -emit-llvm %s -o /dev/null 2>&1 \
+// RUN:     | FileCheck %s -check-prefix CHECK-EABI
+// REQUIRES: arm-registered-target
+
+void emit() {
+  __emit(0xdefe);
+}
+
+// CHECK-MSVC: call void asm sideeffect ".inst.n 0xDEFE", ""()
+// CHECK-EABI: warning: implicit declaration of function '__emit' is invalid in C99
+
+void emit_truncated() {
+  __emit(0x11110000); // movs r0, r0
+}
+
+// CHECK-MSVC: call void asm sideeffect ".inst.n 0x0", ""()
+