Index: llvm/trunk/lib/Transforms/Coroutines/CoroSplit.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Coroutines/CoroSplit.cpp
+++ llvm/trunk/lib/Transforms/Coroutines/CoroSplit.cpp
@@ -654,13 +654,28 @@
   // set.
   do {
     Instruction *Current = Work.pop_back_val();
+    DEBUG(dbgs() << "CoroSplit: Will not relocate: " << *Current << "\n");
     DoNotRelocate.insert(Current);
     for (Value *U : Current->operands()) {
       auto *I = dyn_cast<Instruction>(U);
       if (!I)
         continue;
-      if (isa<AllocaInst>(U))
+
+      if (auto *A = dyn_cast<AllocaInst>(I)) {
+        // Stores to alloca instructions that occur before the coroutine frame
+        // is allocated should not be moved; the stored values may be used by
+        // the coroutine frame allocator. The operands to those stores must also
+        // remain in place.
+        for (const auto &User : A->users())
+          if (auto *SI = dyn_cast<llvm::StoreInst>(User))
+            if (RelocBlocks.count(SI->getParent()) != 0 &&
+                DoNotRelocate.count(SI) == 0) {
+              Work.push_back(SI);
+              DoNotRelocate.insert(SI);
+            }
         continue;
+      }
+
       if (DoNotRelocate.count(I) == 0) {
         Work.push_back(I);
         DoNotRelocate.insert(I);
Index: llvm/trunk/test/Transforms/Coroutines/coro-split-alloc.ll
===================================================================
--- llvm/trunk/test/Transforms/Coroutines/coro-split-alloc.ll
+++ llvm/trunk/test/Transforms/Coroutines/coro-split-alloc.ll
@@ -0,0 +1,64 @@
+; Tests that coro-split passes initialized values to coroutine frame allocator.
+; RUN: opt < %s -coro-split -S | FileCheck %s
+
+define i8* @f(i32 %argument) "coroutine.presplit"="1" {
+entry:
+  %argument.addr = alloca i32, align 4
+  %incremented = add i32 %argument, 1
+  store i32 %incremented, i32* %argument.addr, align 4
+  %id = call token @llvm.coro.id(i32 0, i8* null, i8* null, i8* null)
+  %need.alloc = call i1 @llvm.coro.alloc(token %id)
+  br i1 %need.alloc, label %dyn.alloc, label %begin
+
+dyn.alloc:
+  %size = call i32 @llvm.coro.size.i32()
+  %allocator_argument = load i32, i32* %argument.addr, align 4
+  %alloc = call i8* @custom_alloctor(i32 %size, i32 %allocator_argument)
+  br label %begin
+
+begin:
+  %phi = phi i8* [ null, %entry ], [ %alloc, %dyn.alloc ]
+  %hdl = call i8* @llvm.coro.begin(token %id, i8* %phi)
+  %print_argument = load i32, i32* %argument.addr, align 4
+  call void @print(i32 %print_argument)
+  %0 = call i8 @llvm.coro.suspend(token none, i1 false)
+  switch i8 %0, label %suspend [i8 0, label %resume
+                                i8 1, label %cleanup]
+resume:
+  call void @print(i32 1)
+  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(
+; CHECK: %argument.addr = alloca i32
+; CHECK: %incremented = add i32 %argument, 1
+; CHECK-NEXT: store i32 %incremented, i32* %argument.addr
+; CHECK-LABEL: dyn.alloc:
+; CHECK: %allocator_argument = load i32, i32* %argument.addr
+; CHECK: %alloc = call i8* @custom_alloctor(i32 24, i32 %allocator_argument)
+; CHECK-LABEL: begin:
+; CHECK: %print_argument = load i32, i32* %argument.addr
+; CHECK: call void @print(i32 %print_argument)
+
+declare i8* @llvm.coro.free(token, i8*)
+declare i32 @llvm.coro.size.i32()
+declare i8  @llvm.coro.suspend(token, i1)
+declare void @llvm.coro.resume(i8*)
+declare void @llvm.coro.destroy(i8*)
+
+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* @custom_alloctor(i32, i32)
+declare void @print(i32)
+declare void @free(i8*)