Index: lib/CodeGen/CGBuiltin.cpp
===================================================================
--- lib/CodeGen/CGBuiltin.cpp
+++ lib/CodeGen/CGBuiltin.cpp
@@ -5221,14 +5221,14 @@
            "rbit of unusual size!");
     llvm::Value *Arg = EmitScalarExpr(E->getArg(0));
     return Builder.CreateCall(
-        CGM.getIntrinsic(Intrinsic::aarch64_rbit, Arg->getType()), Arg, "rbit");
+        CGM.getIntrinsic(Intrinsic::bitreverse, Arg->getType()), Arg, "rbit");
   }
   if (BuiltinID == AArch64::BI__builtin_arm_rbit64) {
     assert((getContext().getTypeSize(E->getType()) == 64) &&
            "rbit of unusual size!");
     llvm::Value *Arg = EmitScalarExpr(E->getArg(0));
     return Builder.CreateCall(
-        CGM.getIntrinsic(Intrinsic::aarch64_rbit, Arg->getType()), Arg, "rbit");
+        CGM.getIntrinsic(Intrinsic::bitreverse, Arg->getType()), Arg, "rbit");
   }
 
   if (BuiltinID == AArch64::BI__clear_cache) {
Index: test/CodeGen/arm_acle.c
===================================================================
--- test/CodeGen/arm_acle.c
+++ test/CodeGen/arm_acle.c
@@ -245,14 +245,14 @@
 
 // ARM-LABEL: test_rbit
 // AArch32: call i32 @llvm.arm.rbit
-// AArch64: call i32 @llvm.aarch64.rbit.i32
+// AArch64: call i32 @llvm.bitreverse.i32
 uint32_t test_rbit(uint32_t t) {
   return __rbit(t);
 }
 
 // ARM-LABEL: test_rbitl
 // AArch32: call i32 @llvm.arm.rbit
-// AArch64: call i64 @llvm.aarch64.rbit.i64
+// AArch64: call i64 @llvm.bitreverse.i64
 long test_rbitl(long t) {
   return __rbitl(t);
 }
@@ -260,7 +260,7 @@
 // ARM-LABEL: test_rbitll
 // AArch32: call i32 @llvm.arm.rbit
 // AArch32: call i32 @llvm.arm.rbit
-// AArch64: call i64 @llvm.aarch64.rbit.i64
+// AArch64: call i64 @llvm.bitreverse.i64
 uint64_t test_rbitll(uint64_t t) {
   return __rbitll(t);
 }
Index: test/CodeGen/builtins-arm64.c
===================================================================
--- test/CodeGen/builtins-arm64.c
+++ test/CodeGen/builtins-arm64.c
@@ -10,12 +10,12 @@
 // CHECK: call {{.*}} @llvm.thread.pointer()
 }
 
-// CHECK: call {{.*}} @llvm.aarch64.rbit.i32(i32 %a)
+// CHECK: call {{.*}} @llvm.bitreverse.i32(i32 %a)
 unsigned rbit(unsigned a) {
   return __builtin_arm_rbit(a);
 }
 
-// CHECK: call {{.*}} @llvm.aarch64.rbit.i64(i64 %a)
+// CHECK: call {{.*}} @llvm.bitreverse.i64(i64 %a)
 unsigned long long rbit64(unsigned long long a) {
   return __builtin_arm_rbit64(a);
 }