Index: include/clang/Basic/BuiltinsAArch64.def
===================================================================
--- include/clang/Basic/BuiltinsAArch64.def
+++ include/clang/Basic/BuiltinsAArch64.def
@@ -86,6 +86,9 @@
 LANGBUILTIN(__sev,   "v", "",   ALL_MS_LANGUAGES)
 LANGBUILTIN(__sevl,  "v", "",   ALL_MS_LANGUAGES)
 
+// Misc
+BUILTIN(__builtin_sponentry, "v*", "c")
+
 TARGET_HEADER_BUILTIN(_BitScanForward, "UcUNi*UNi", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
 TARGET_HEADER_BUILTIN(_BitScanReverse, "UcUNi*UNi", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
 TARGET_HEADER_BUILTIN(_BitScanForward64, "UcUNi*ULLi", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
Index: lib/CodeGen/CGBuiltin.cpp
===================================================================
--- lib/CodeGen/CGBuiltin.cpp
+++ lib/CodeGen/CGBuiltin.cpp
@@ -7233,6 +7233,11 @@
     return Builder.CreateCall(F);
   }
 
+  if (BuiltinID == AArch64::BI__builtin_sponentry) {
+    llvm::Function *F = CGM.getIntrinsic(Intrinsic::sponentry);
+    return Builder.CreateCall(F);
+  }
+
   // Find out if any arguments are required to be integer constant
   // expressions.
   unsigned ICEArguments = 0;
Index: test/CodeGen/builtin-sponentry.c
===================================================================
--- test/CodeGen/builtin-sponentry.c
+++ test/CodeGen/builtin-sponentry.c
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -triple aarch64-windows-gnu -Oz -emit-llvm %s -o - | FileCheck %s
+
+void *test_sponentry() {
+  return __builtin_sponentry();
+}
+// CHECK-LABEL: define dso_local i8* @test_sponentry()
+// CHECK: = tail call i8* @llvm.sponentry()
+// CHECK: ret i8*