Index: llvm/lib/Transforms/Coroutines/CoroCleanup.cpp
===================================================================
--- llvm/lib/Transforms/Coroutines/CoroCleanup.cpp
+++ llvm/lib/Transforms/Coroutines/CoroCleanup.cpp
@@ -12,6 +12,7 @@
 #include "llvm/IR/InstIterator.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/Pass.h"
+#include "llvm/Transforms/Scalar/EarlyCSE.h"
 #include "llvm/Transforms/Scalar/SimplifyCFG.h"
 
 using namespace llvm;
@@ -146,6 +147,7 @@
 
   FunctionPassManager FPM;
   FPM.addPass(SimplifyCFGPass());
+  FPM.addPass(EarlyCSEPass());
 
   Lowerer L(M);
   for (auto &F : M)
Index: llvm/test/Transforms/Coroutines/coro-readnone-06.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/Coroutines/coro-readnone-06.ll
@@ -0,0 +1,58 @@
+; Tests that the readnone function which don't cross suspend points could be optimized expectly.
+; RUN: opt < %s -S -passes='default<O1>' -opaque-pointers | FileCheck %s
+
+define ptr @f() "coroutine.presplit" {
+entry:
+  %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)
+  %hdl = call i8* @llvm.coro.begin(token %id, i8* %alloc)
+  %sus_result = call i8 @llvm.coro.suspend(token none, i1 false)
+  switch i8 %sus_result, label %suspend [i8 0, label %resume
+                                         i8 1, label %cleanup]
+resume:
+  %i = call i32 @readnone_func() readnone
+  %j = call i32 @readnone_func() readnone
+  %cmp = icmp eq i32 %i, %j
+  br i1 %cmp, label %same, label %diff
+
+same:
+  call void @print_same()
+  br label %cleanup
+
+diff:
+  call void @print_diff()
+  br label %cleanup
+
+cleanup:
+  %mem = call i8* @llvm.coro.free(token %id, i8* %hdl)
+  call void @free(i8* %mem)
+  br label %suspend
+
+suspend:
+  call i1 @llvm.coro.end(i8* %hdl, i1 0)
+  ret i8* %hdl
+}
+
+; CHECK-LABEL: f.resume(
+; CHECK-NEXT: entry
+; CHECK-NEXT:   call i32 @readnone_func()
+; CHECK-NEXT:   call void @print_same()
+; CHECK-NEXT:   call void @free
+; CHECK-NEXT:   ret void
+
+declare i32 @readnone_func() readnone
+
+declare void @print_same()
+declare void @print_diff()
+declare i8* @llvm.coro.free(token, i8*)
+declare i32 @llvm.coro.size.i32()
+declare i8  @llvm.coro.suspend(token, i1)
+
+declare token @llvm.coro.id(i32, i8*, i8*, i8*)
+declare i1 @llvm.coro.alloc(token)
+declare i8* @llvm.coro.begin(token, i8*)
+declare i1 @llvm.coro.end(i8*, i1)
+
+declare noalias i8* @malloc(i32)
+declare void @free(i8*)