diff --git a/lib/Transforms/Coroutines/CoroEarly.cpp b/lib/Transforms/Coroutines/CoroEarly.cpp
index 1660e41ba83..0185f8de5fa 100644
--- a/lib/Transforms/Coroutines/CoroEarly.cpp
+++ b/lib/Transforms/Coroutines/CoroEarly.cpp
@@ -179,7 +179,6 @@ bool Lowerer::lowerEarlyIntrinsics(Function &F) {
         // with a coroutine attribute.
         if (auto *CII = cast<CoroIdInst>(&I)) {
           if (CII->getInfo().isPreSplit()) {
-            F.addFnAttr(CORO_PRESPLIT_ATTR, UNPREPARED_FOR_SPLIT);
             setCannotDuplicate(CII);
             CII->setCoroutineSelf();
             CoroId = cast<CoroIdInst>(&I);
diff --git a/test/Transforms/Coroutines/coro-debug-O2.ll b/test/Transforms/Coroutines/coro-debug-O2.ll
index 0ab8cfe84ff..7777c94a282 100644
--- a/test/Transforms/Coroutines/coro-debug-O2.ll
+++ b/test/Transforms/Coroutines/coro-debug-O2.ll
@@ -9,7 +9,7 @@
 ; CHECK: ![[PROMISEVAR_RESUME]] = !DILocalVariable(name: "__promise"
 %promise_type = type { i32, i32, double }
 
-define void @f() !dbg !8 {
+define void @f() "coroutine.presplit"="0" !dbg !8 {
 entry:
     %__promise = alloca %promise_type, align 8
     %0 = bitcast %promise_type* %__promise to i8*
diff --git a/test/Transforms/Coroutines/coro-debug-frame-variable.ll b/test/Transforms/Coroutines/coro-debug-frame-variable.ll
index 433488bfdde..9dbda92ddce 100644
--- a/test/Transforms/Coroutines/coro-debug-frame-variable.ll
+++ b/test/Transforms/Coroutines/coro-debug-frame-variable.ll
@@ -63,7 +63,7 @@
 ; CHECK: ![[IVAR_RESUME]] = !DILocalVariable(name: "i"
 ; CHECK: ![[JVAR_RESUME]] = !DILocalVariable(name: "j"
 ; CHECK: ![[JDBGLOC_RESUME]] = !DILocation(line: 32, column: 7, scope: ![[RESUME_SCOPE]])
-define void @f() {
+define void @f() "coroutine.presplit"="0" {
 entry:
   %__promise = alloca i8, align 8
   %i = alloca i32, align 4
diff --git a/test/Transforms/Coroutines/coro-split-01.ll b/test/Transforms/Coroutines/coro-split-01.ll
index ca9faa566eb..04d8fbdc963 100644
--- a/test/Transforms/Coroutines/coro-split-01.ll
+++ b/test/Transforms/Coroutines/coro-split-01.ll
@@ -2,7 +2,7 @@
 ; RUN: opt < %s -S -enable-coroutines -O2 | FileCheck %s
 ; RUN: opt < %s -S -enable-coroutines -passes='default<O2>' | FileCheck %s
 
-define i8* @f() {
+define i8* @f() "coroutine.presplit"="0" {
 entry:
   %id = call token @llvm.coro.id(i32 0, i8* null, i8* null, i8* null)
   %need.dyn.alloc = call i1 @llvm.coro.alloc(token %id)
diff --git a/test/Transforms/Coroutines/coro-split-recursive.ll b/test/Transforms/Coroutines/coro-split-recursive.ll
index 0b6909fe4e6..907ec1bbd2c 100644
--- a/test/Transforms/Coroutines/coro-split-recursive.ll
+++ b/test/Transforms/Coroutines/coro-split-recursive.ll
@@ -13,7 +13,7 @@ declare i8 @llvm.coro.suspend(token, i1)
 ; CHECK: call void @foo()
 ; CHECK-LABEL: define {{.*}}void @foo.destroy(
 
-define void @foo() {
+define void @foo() "coroutine.presplit"="0" {
 entry:
   %__promise = alloca i32, align 8
   %0 = bitcast i32* %__promise to i8*
diff --git a/test/Transforms/Coroutines/ex0.ll b/test/Transforms/Coroutines/ex0.ll
index de5752387cf..9ca29fc2a38 100644
--- a/test/Transforms/Coroutines/ex0.ll
+++ b/test/Transforms/Coroutines/ex0.ll
@@ -2,7 +2,7 @@
 ; RUN: opt < %s -enable-coroutines -O2 -preserve-alignment-assumptions-during-inlining=false -S | FileCheck %s
 ; RUN: opt < %s -enable-coroutines -aa-pipeline=basic-aa -passes='default<O2>' -preserve-alignment-assumptions-during-inlining=false -S | FileCheck %s
 
-define i8* @f(i32 %n) {
+define i8* @f(i32 %n) "coroutine.presplit"="0" {
 entry:
   %id = call token @llvm.coro.id(i32 0, i8* null, i8* null, i8* null)
   %size = call i32 @llvm.coro.size.i32()
diff --git a/test/Transforms/Coroutines/ex1.ll b/test/Transforms/Coroutines/ex1.ll
index 42f603865b6..13276ef3778 100644
--- a/test/Transforms/Coroutines/ex1.ll
+++ b/test/Transforms/Coroutines/ex1.ll
@@ -2,7 +2,7 @@
 ; RUN: opt < %s -O2 -enable-coroutines -preserve-alignment-assumptions-during-inlining=false -S | FileCheck %s
 ; RUN: opt < %s -aa-pipeline=basic-aa -passes='default<O2>' -enable-coroutines -preserve-alignment-assumptions-during-inlining=false -S | FileCheck %s
 
-define i8* @f(i32 %n) {
+define i8* @f(i32 %n) "coroutine.presplit"="0" {
 entry:
   %id = call token @llvm.coro.id(i32 0, i8* null, i8* null, i8* null)
   %size = call i32 @llvm.coro.size.i32()
diff --git a/test/Transforms/Coroutines/ex2.ll b/test/Transforms/Coroutines/ex2.ll
index 584bc909a4e..5f4431a9fd0 100644
--- a/test/Transforms/Coroutines/ex2.ll
+++ b/test/Transforms/Coroutines/ex2.ll
@@ -2,7 +2,7 @@
 ; RUN: opt < %s -O2 -enable-coroutines -S | FileCheck %s
 ; RUN: opt < %s -passes='default<O2>' -enable-coroutines -S | FileCheck %s
 
-define i8* @f(i32 %n) {
+define i8* @f(i32 %n) "coroutine.presplit"="0" {
 entry:
   %id = call token @llvm.coro.id(i32 0, i8* null, i8* null, i8* null)
   %need.dyn.alloc = call i1 @llvm.coro.alloc(token %id)
diff --git a/test/Transforms/Coroutines/ex3.ll b/test/Transforms/Coroutines/ex3.ll
index 85cf53fb576..a822a69ec89 100644
--- a/test/Transforms/Coroutines/ex3.ll
+++ b/test/Transforms/Coroutines/ex3.ll
@@ -2,7 +2,7 @@
 ; RUN: opt < %s -O2 -enable-coroutines -S | FileCheck %s
 ; RUN: opt < %s -aa-pipeline=basic-aa -passes='default<O2>' -enable-coroutines -S | FileCheck %s
 
-define i8* @f(i32 %n) {
+define i8* @f(i32 %n) "coroutine.presplit"="0" {
 entry:
   %id = call token @llvm.coro.id(i32 0, i8* null, i8* null, i8* null)
   %size = call i32 @llvm.coro.size.i32()
diff --git a/test/Transforms/Coroutines/ex4.ll b/test/Transforms/Coroutines/ex4.ll
index e60bc2c691f..a519f4e9bd1 100644
--- a/test/Transforms/Coroutines/ex4.ll
+++ b/test/Transforms/Coroutines/ex4.ll
@@ -2,7 +2,7 @@
 ; RUN: opt < %s -O2 -enable-coroutines -S | FileCheck %s
 ; RUN: opt < %s -passes='default<O2>' -enable-coroutines -S | FileCheck %s
 
-define i8* @f(i32 %n) {
+define i8* @f(i32 %n) "coroutine.presplit"="0" {
 entry:
   %promise = alloca i32
   %pv = bitcast i32* %promise to i8*
diff --git a/test/Transforms/Coroutines/ex5.ll b/test/Transforms/Coroutines/ex5.ll
index dd566505ba8..2cab0ac90be 100644
--- a/test/Transforms/Coroutines/ex5.ll
+++ b/test/Transforms/Coroutines/ex5.ll
@@ -2,7 +2,7 @@
 ; RUN: opt < %s -O2 -enable-coroutines -preserve-alignment-assumptions-during-inlining=false -S | FileCheck %s
 ; RUN: opt < %s -aa-pipeline=basic-aa -passes='default<O2>' -enable-coroutines -preserve-alignment-assumptions-during-inlining=false -S | FileCheck %s
 
-define i8* @f(i32 %n) {
+define i8* @f(i32 %n) "coroutine.presplit"="0" {
 entry:
   %id = call token @llvm.coro.id(i32 0, i8* null, i8* null, i8* null)
   %size = call i32 @llvm.coro.size.i32()
diff --git a/test/Transforms/Coroutines/phi-coro-end.ll b/test/Transforms/Coroutines/phi-coro-end.ll
index d7ee2f58adb..39a34102796 100644
--- a/test/Transforms/Coroutines/phi-coro-end.ll
+++ b/test/Transforms/Coroutines/phi-coro-end.ll
@@ -2,7 +2,7 @@
 ; RUN: opt < %s -O2 -enable-coroutines -S | FileCheck %s
 ; RUN: opt < %s -aa-pipeline=basic-aa -passes='default<O2>' -enable-coroutines -S | FileCheck %s
 
-define i8* @f(i32 %n) {
+define i8* @f(i32 %n) "coroutine.presplit"="0" {
 entry:
   %id = call token @llvm.coro.id(i32 0, i8* null, i8* null, i8* null)
   %size = call i32 @llvm.coro.size.i32()
diff --git a/test/Transforms/Coroutines/restart-trigger.ll b/test/Transforms/Coroutines/restart-trigger.ll
index ca74f92fb89..8e510959dcb 100644
--- a/test/Transforms/Coroutines/restart-trigger.ll
+++ b/test/Transforms/Coroutines/restart-trigger.ll
@@ -12,7 +12,7 @@
 ; CHECK:      CoroSplit: Processing coroutine 'f' state: 0
 ; CHECK-NEXT: CoroSplit: Processing coroutine 'f' state: 1
 
-define void @f() {
+define void @f() "coroutine.presplit"="0" {
   %id = call token @llvm.coro.id(i32 0, i8* null, i8* null, i8* null)
   %size = call i32 @llvm.coro.size.i32()
   %alloc = call i8* @malloc(i32 %size)