diff --git a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
--- a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
+++ b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
@@ -453,6 +453,12 @@
     // The field size is always the alloc size of the type.
     uint64_t FieldSize = DL.getTypeAllocSize(Ty);
 
+    // For an alloca with size=0, we don't need to add a field and they
+    // can just point to any index in the frame. Use index 0.
+    if (FieldSize == 0) {
+      return 0;
+    }
+
     // The field alignment might not be the type alignment, but we need
     // to remember the type alignment anyway to build the type.
     Align TyAlignment = DL.getABITypeAlign(Ty);
diff --git a/llvm/test/Transforms/Coroutines/coro-zero-alloca.ll b/llvm/test/Transforms/Coroutines/coro-zero-alloca.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/Coroutines/coro-zero-alloca.ll
@@ -0,0 +1,81 @@
+; RUN: opt < %s -O2 --enable-coroutines -S | FileCheck %s
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64--linux"
+
+declare i8* @malloc(i64)
+declare void @free(i8*)
+declare void @usePointer(i8*)
+declare void @usePointer2([0 x i8]*)
+
+declare token @llvm.coro.id(i32, i8* readnone, i8* nocapture readonly, i8*)
+declare i64 @llvm.coro.size.i64()
+declare i8* @llvm.coro.begin(token, i8* writeonly)
+declare i8 @llvm.coro.suspend(token, i1)
+declare i1 @llvm.coro.end(i8*, i1)
+declare i8* @llvm.coro.free(token, i8* nocapture readonly)
+declare token @llvm.coro.save(i8*)
+
+define void @foo() {
+entry:
+  %a0 = alloca [0 x i8]
+  %a1 = alloca i32
+  %a2 = alloca [0 x i8]
+  %a3 = alloca [0 x i8]
+  %a4 = alloca i16
+  %a5 = alloca [0 x i8]
+  %a0.cast = bitcast [0 x i8]* %a0 to i8*
+  %a1.cast = bitcast i32* %a1 to i8*
+  %a2.cast = bitcast [0 x i8]* %a2 to i8*
+  %a3.cast = bitcast [0 x i8]* %a3 to i8*
+  %a4.cast = bitcast i16* %a4 to i8*
+  %coro.id = call token @llvm.coro.id(i32 0, i8* null, i8* null, i8* null)
+  %coro.size = call i64 @llvm.coro.size.i64()
+  %coro.alloc = call i8* @malloc(i64 %coro.size)
+  %coro.state = call i8* @llvm.coro.begin(token %coro.id, i8* %coro.alloc)
+  %coro.save = call token @llvm.coro.save(i8* %coro.state)
+  %call.suspend = call i8 @llvm.coro.suspend(token %coro.save, i1 false)
+  switch i8 %call.suspend, label %suspend [
+    i8 0, label %wakeup
+    i8 1, label %cleanup
+  ]
+
+wakeup:                                           ; preds = %entry
+  call void @usePointer(i8* %a0.cast)
+  call void @usePointer(i8* %a1.cast)
+  call void @usePointer(i8* %a2.cast)
+  call void @usePointer(i8* %a3.cast)
+  call void @usePointer(i8* %a4.cast)
+  call void @usePointer2([0 x i8]* %a5)
+  br label %cleanup
+
+suspend:                                          ; preds = %cleanup, %entry
+  %unused = call i1 @llvm.coro.end(i8* %coro.state, i1 false)
+  ret void
+
+cleanup:                                          ; preds = %wakeup, %entry
+  %coro.memFree = call i8* @llvm.coro.free(token %coro.id, i8* %coro.state)
+  call void @free(i8* %coro.memFree)
+  br label %suspend
+}
+
+; CHECK:       %foo.Frame = type { void (%foo.Frame*)*, void (%foo.Frame*)*, i32, i16, i1 }
+
+; CHECK-LABEL: define internal fastcc void @foo.resume(%foo.Frame* noalias nonnull align 8 dereferenceable(24) %FramePtr) {
+; CHECK-NEXT:    entry.resume:
+; CHECK-NEXT:      %vFrame = bitcast %foo.Frame* %FramePtr to i8*
+; CHECK-NEXT:      %a1.reload.addr = getelementptr inbounds %foo.Frame, %foo.Frame* %FramePtr, i64 0, i32 2
+; CHECK-NEXT:      %a4.reload.addr = getelementptr inbounds %foo.Frame, %foo.Frame* %FramePtr, i64 0, i32 3
+; CHECK-NEXT:      %a0.reload.addr = bitcast %foo.Frame* %FramePtr to [0 x i8]*
+; CHECK-NEXT:      %a4.cast = bitcast i16* %a4.reload.addr to i8*
+; CHECK-NEXT:      %a3.cast = bitcast %foo.Frame* %FramePtr to i8*
+; CHECK-NEXT:      %a1.cast = bitcast i32* %a1.reload.addr to i8*
+; CHECK-NEXT:      call void @usePointer(i8* nonnull %a3.cast)
+; CHECK-NEXT:      call void @usePointer(i8* nonnull %a1.cast)
+; CHECK-NEXT:      call void @usePointer(i8* nonnull %a3.cast)
+; CHECK-NEXT:      call void @usePointer(i8* nonnull %a3.cast)
+; CHECK-NEXT:      call void @usePointer(i8* nonnull %a4.cast)
+; CHECK-NEXT:      call void @usePointer2([0 x i8]* nonnull %a0.reload.addr)
+; CHECK-NEXT:      call void @free(i8* %vFrame)
+; CHECK-NEXT:      ret void
+; CHECK-NEXT:    }