[coroutines] Adding builtins for coroutine intrinsics and backendutil support.

[GorNishanov]

Summary

With this commit simple coroutines can be created in plain C using coroutine builtins.

[rsmith]

include/clang/Basic/Builtins.def

1343

I don't really like having builtins which will result in errors from the middle-end in some cases; there are a bunch of side-conditions on llvm.coro.id that aren't being enforced here. In particular, this call must be present in any function that also calls coro.alloc and friends, and must dominate those other calls.

Modeling the 'token' value as a void* also seems problematic. If the user uses that value for anything other than the argument to a builtin that wants the token, bad things are going to happen.

(From dinner discussion:) one possible way to deal with this would be to generate the call to @llvm.coro.id implicitly in the entry block, in a function that uses the other builtins. The challenge then is communicating the promise object to the intrinsic, which is problematic if we allow an arbitrary pointer value to be passed in.

However, we're only interested in supporting a stack variable as the promise object, so here's one possible approach:

• add an attribute that can be applied to a local variable to mark it as the promise object for the current function
• remove the __builtin_coro_id builtin, and instead implicitly generate the llvm.coro.id intrinsic call in the entry block when we need its token or see a promise object
• when we emit a local variable with the promise-object attribute, update the llvm.coro.id call to pass its alloca as the promise object
• remove the 'token' parameter from __builtin_coro_alloc etc, and instead implicitly provide it from the result of the implicit llvm.coro.id call

test/Coroutines/coro.c

1 ↗

(On Diff #70780)

Please just check the IR generated by the frontend is correct for each of the intrinsics rather than using an end-to-end test that depends on the LLVM IR optimizations. You can use -disable-llvm-optzns to see the IR coming out of clang before the mandatory coroutine passes monkey with it.

[GorNishanov]

1. Added documentation for builtins
2. Added a couple of tests with -disable-llvm-passes to check that builtins are emitted correctly

[GorNishanov]

include/clang/Basic/Builtins.def

1343

I added clarification to the documentation that all but four builtins are for internal compiler use and for the use as development tools for the coroutine feature, so, possibly we should not worry too much about people misusing them.

Alternatively, I can get rid of most of the coroutine builtins, apart from the ones that are intended to be used to implement coroutine standard library facilities.

At the moment, I think, we should prioritize getting C++ Coroutines online. We can polish C coroutine story later.

test/Coroutines/coro.c

1 ↗

(On Diff #70780)

I added two tests to check that builtins are lowered to coro intrinsics correctly. I would like to keep a small number of "-O2" tests as a sanity end-to-end testing.

[GorNishanov]

Improved diagnostics in CGCoroutine and ping...

[GorNishanov]

rebase on top of the trunk

[rsmith]

docs/LanguageExtensions.rst

1886

Return type here is void*, not void.

1916

Remove both "the"s here.

test/CodeGenCoroutines/O2-coro.c

2

Please do not test the output of LLVM optimization in a clang unit test. It seems fine to just remove this test, you have the relevant coverage elsewhere.

test/CodeGenCoroutines/coro-builtins.c

6

Use a pattern here rather than hardcoding %0; it's not reasonable to assume that this will always be the first instruction in the function.

Please also pass actual arguments here so we can test they're passed to the correct parameter.

[GorNishanov]

1. O2 test removed
2. Update LanguageExtensions.rst with suggested edits
3. coro-builtins.c test now passes useful arguments and pattern matches that proper arguments are passed in emitted intrinsics.

[GorNishanov]

Closed by commit r283155 - [coroutines] Adding builtins for coroutine intrinsics and backendutil support.

For some reason phabricator did not close it automatically.

docs/LanguageExtensions.rst

 
 * Integer types.
 * Floating-point types.
 * Vector types.
 
 Note that the compiler does not guarantee that non-temporal loads or stores
 will be used.
 
+C++ Coroutines support builtins
+--------------------------------
+
+.. warning::
+  This is a work in progress. Compatibility across Clang/LLVM releases is not 
+  guaranteed.
+
+Clang provides experimental builtins to support C++ Coroutines as defined by
+http://wg21.link/P0057. The following four are intended to be used by the
+standard library to implement `std::experimental::coroutine_handle` type.
+
+**Syntax**:
+
+.. code-block:: c
+
+  void __builtin_coro_resume(void *addr);
+  void __builtin_coro_destroy(void *addr);
+  bool __builtin_coro_done(void *addr);
+  void __builtin_coro_promise(void *addr, int alignment, bool from_promise)
+
+**Example of use**:
+
+.. code-block:: c++
+
+  template <> struct coroutine_handle<void> {
+    void resume() const { __builtin_coro_resume(ptr); }
+    void destroy() const { __builtin_coro_destroy(ptr); }
+    bool done() const { return __builtin_coro_done(ptr); }
+    // ...
+  protected:
+    void *ptr;
+  };
+
+  template <typename Promise> struct coroutine_handle : coroutine_handle<> {
+    // ...
+    Promise &promise() const {
+      return *reinterpret_cast<Promise *>(
+        __builtin_coro_promise(ptr, alignof(Promise), /*from-promise=*/false));
+    }
+    static coroutine_handle from_promise(Promise &promise) {
+      coroutine_handle p;
+      p.ptr = __builtin_coro_promise(&promise, alignof(Promise),
+                                                      /*from-promise=*/true);
+      return p;
+    }
+  };
+
+
+Other coroutine builtins are either for the internal clang use or for the use
+during development of the coroutine feature. See `Coroutines in LLVM
+<http://llvm.org/docs/Coroutines.html#intrinsics>`_ for
+more information on their semantics. Note that builtins matching the intrinsics
+that take token as the first parameter (llvm.coro.begin, llvm.coro.alloc, 
+llvm.coro.free and llvm.coro.suspend) omit the token parameter and fill it to
+an appropriate value during the emission.
+
+**Syntax**:
+
+.. code-block:: c
+
+  size_t __builtin_coro_size()
+  void *__builtin_coro_frame()
+  void *__builtin_coro_free(void* coro_frame)
+
+  void *__builtin_coro_id(int align, void* promise, void *fnaddr, void *parts)
+  bool __builtin_coro_alloc()
+  void* __builtin_coro_begin(void* memory)
+  void __builtin_coro_end(void* coro_frame, bool unwind)
+  char __builtin_coro_suspend(bool final)
+  bool __builtin_coro_param(void* original, void* copy)
+
+Note that there is no builtin matching the `llvm.coro.save` intrinsic. LLVM
+automatically will insert one if the first argument to `llvm.coro.suspend` is
+token `none`. If a user calls `__builin_suspend`, clang will insert `token none`
+as the first argument to the intrinsic.
+
 Non-standard C++11 Attributes
 =============================
 
 Clang's non-standard C++11 attributes live in the ``clang`` attribute
 namespace.
 
 Clang supports GCC's ``gnu`` attribute namespace. All GCC attributes which
 are accepted with the ``__attribute__((foo))`` syntax are also accepted as

include/clang/Basic/Builtins.def

 // Safestack builtins
 BUILTIN(__builtin___get_unsafe_stack_start, "v*", "Fn")
 BUILTIN(__builtin___get_unsafe_stack_ptr, "v*", "Fn")
 
 // Nontemporal loads/stores builtins
 BUILTIN(__builtin_nontemporal_store, "v.", "t")
 BUILTIN(__builtin_nontemporal_load, "v.", "t")
 
+// Coroutine intrinsics.
+BUILTIN(__builtin_coro_resume, "vv*", "")
+BUILTIN(__builtin_coro_destroy, "vv*", "")
+BUILTIN(__builtin_coro_done, "bv*", "n")
+BUILTIN(__builtin_coro_promise, "v*v*IiIb", "n")
+
+BUILTIN(__builtin_coro_size, "z", "n")
+BUILTIN(__builtin_coro_frame, "v*", "n")
+BUILTIN(__builtin_coro_free, "v*v*", "n")
+
+BUILTIN(__builtin_coro_id, "v*Iiv*v*v*", "n")
+BUILTIN(__builtin_coro_alloc, "b", "n")
+BUILTIN(__builtin_coro_begin, "v*v*", "n")
+BUILTIN(__builtin_coro_end, "vv*Ib", "n")
+BUILTIN(__builtin_coro_suspend, "cIb", "n")
+BUILTIN(__builtin_coro_param, "bv*v*", "n")
 // OpenCL v2.0 s6.13.16, s9.17.3.5 - Pipe functions.
 // We need the generic prototype, since the packet type could be anything.
 LANGBUILTIN(read_pipe, "i.", "tn", OCLC20_LANG)
 LANGBUILTIN(write_pipe, "i.", "tn", OCLC20_LANG)
 
 LANGBUILTIN(reserve_read_pipe, "i.", "tn", OCLC20_LANG)
 LANGBUILTIN(reserve_write_pipe, "i.", "tn", OCLC20_LANG)
 

lib/CodeGen/BackendUtil.cpp

 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/PrettyStackTrace.h"
 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/Timer.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetOptions.h"
 #include "llvm/Target/TargetSubtargetInfo.h"
+#include "llvm/Transforms/Coroutines.h"
 #include "llvm/Transforms/IPO.h"
 #include "llvm/Transforms/IPO/AlwaysInliner.h"
 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
 #include "llvm/Transforms/Instrumentation.h"
 #include "llvm/Transforms/ObjCARC.h"
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Scalar/GVN.h"
 #include "llvm/Transforms/Utils/SymbolRewriter.h"
void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
 
   if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
                            addDataFlowSanitizerPass);
     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
                            addDataFlowSanitizerPass);
   }
 
+  if (LangOpts.Coroutines)
+    addCoroutinePassesToExtensionPoints(PMBuilder);
+
   if (LangOpts.Sanitize.hasOneOf(SanitizerKind::Efficiency)) {
     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
                            addEfficiencySanitizerPass);
     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
                            addEfficiencySanitizerPass);
   }
 
   // Set up the per-function pass manager.

lib/CodeGen/CGBuiltin.cpp

 
   case Builtin::BI__GetExceptionInfo: {
     if (llvm::GlobalVariable *GV =
             CGM.getCXXABI().getThrowInfo(FD->getParamDecl(0)->getType()))
       return RValue::get(llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy));
     break;
   }
 
+  case Builtin::BI__builtin_coro_size: {
+    auto & Context = getContext();
+    auto SizeTy = Context.getSizeType();
+    auto T = Builder.getIntNTy(Context.getTypeSize(SizeTy));
+    Value *F = CGM.getIntrinsic(Intrinsic::coro_size, T);
+    return RValue::get(Builder.CreateCall(F));
+  }
+
+  case Builtin::BI__builtin_coro_id:
+    return EmitCoroutineIntrinsic(E, Intrinsic::coro_id);
+  case Builtin::BI__builtin_coro_promise:
+    return EmitCoroutineIntrinsic(E, Intrinsic::coro_promise);
+  case Builtin::BI__builtin_coro_resume:
+    return EmitCoroutineIntrinsic(E, Intrinsic::coro_resume);
+  case Builtin::BI__builtin_coro_frame:
+    return EmitCoroutineIntrinsic(E, Intrinsic::coro_frame);
+  case Builtin::BI__builtin_coro_free:
+    return EmitCoroutineIntrinsic(E, Intrinsic::coro_free);
+  case Builtin::BI__builtin_coro_destroy:
+    return EmitCoroutineIntrinsic(E, Intrinsic::coro_destroy);
+  case Builtin::BI__builtin_coro_done:
+    return EmitCoroutineIntrinsic(E, Intrinsic::coro_done);
+  case Builtin::BI__builtin_coro_alloc:
+    return EmitCoroutineIntrinsic(E, Intrinsic::coro_alloc);
+  case Builtin::BI__builtin_coro_begin:
+    return EmitCoroutineIntrinsic(E, Intrinsic::coro_begin);
+  case Builtin::BI__builtin_coro_end:
+    return EmitCoroutineIntrinsic(E, Intrinsic::coro_end);
+  case Builtin::BI__builtin_coro_suspend:
+    return EmitCoroutineIntrinsic(E, Intrinsic::coro_suspend);
+  case Builtin::BI__builtin_coro_param:
+    return EmitCoroutineIntrinsic(E, Intrinsic::coro_param);
+
   // OpenCL v2.0 s6.13.16.2, Built-in pipe read and write functions
   case Builtin::BIread_pipe:
   case Builtin::BIwrite_pipe: {
     Value *Arg0 = EmitScalarExpr(E->getArg(0)),
           *Arg1 = EmitScalarExpr(E->getArg(1));
     CGOpenCLRuntime OpenCLRT(CGM);
     Value *PacketSize = OpenCLRT.getPipeElemSize(E->getArg(0));
     Value *PacketAlign = OpenCLRT.getPipeElemAlign(E->getArg(0));

lib/CodeGen/CGCoroutine.cpp

+//===----- CGCoroutine.cpp - Emit LLVM Code for C++ coroutines ------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This contains code dealing with C++ code generation of coroutines.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CodeGenFunction.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/Value.h"
+
+using namespace clang;
+using namespace CodeGen;
+
+namespace clang {
+namespace CodeGen {
+
+struct CGCoroData {
+  // More members to come in the future patches
+
+  // Stores the llvm.coro.id emitted in the function so that we can supply it
+  // as the first argument to coro.begin, coro.alloc and coro.free intrinsics.
+  // Note: llvm.coro.id returns a token that cannot be directly expressed in a
+  // builtin.
+  llvm::CallInst *CoroId = nullptr;
+};
+}
+}
+clang::CodeGen::CodeGenFunction::CGCoroInfo::CGCoroInfo() {}
+CodeGenFunction::CGCoroInfo::~CGCoroInfo() {}
+
+static void createCoroDataIfNeeded(CodeGenFunction::CGCoroInfo& CurCoro) {
+  if (CurCoro.Data)
+    return;
+
+  CurCoro.Data = std::unique_ptr<CGCoroData>(new CGCoroData);
+}
+
+// Emit coroutine intrinsic and patch up arguments of the token type.
+RValue CodeGenFunction::EmitCoroutineIntrinsic(const CallExpr *E,
+                                               unsigned int IID) {
+  SmallVector<llvm::Value*, 8> Args;
+  switch (IID) {
+  default:
+    break;
+  // The following three intrinsics take a token parameter referring to a token
+  // returned by earlier call to @llvm.coro.id. Since we cannot represent it in
+  // builtins, we patch it up here.
+  case llvm::Intrinsic::coro_alloc:
+  case llvm::Intrinsic::coro_begin:
+  case llvm::Intrinsic::coro_free: {
+    if (CurCoro.Data && CurCoro.Data->CoroId) {
+      Args.push_back(CurCoro.Data->CoroId);
+      break;
+    }
+    CGM.Error(E->getLocStart(), "this builtin expect that __builtin_coro_id has"
+      "been used earlier in this function");
+    // Fallthrough to the next case to add TokenNone as the first argument.
+  }
+  // @llvm.coro.suspend takes a token parameter. Add token 'none' as the first
+  // argument.
+  case llvm::Intrinsic::coro_suspend:
+    Args.push_back(llvm::ConstantTokenNone::get(getLLVMContext()));
+    break;
+  }
+  for (auto &Arg : E->arguments())
+    Args.push_back(EmitScalarExpr(Arg));
+
+  llvm::Value *F = CGM.getIntrinsic(IID);
+  llvm::CallInst *Call = Builder.CreateCall(F, Args);
+
+  // If we see @llvm.coro.id remember it. We will update coro.alloc, coro.begin
+  // and coro.free intrinsics to refer to it.
+  if (IID == llvm::Intrinsic::coro_id) {
+    createCoroDataIfNeeded(CurCoro);
+
+    if (CurCoro.Data->CoroId) {
+      CGM.Error(E->getLocStart(),
+                "only one __builtin_coro_id can be used in a function");
+    }
+    else {
+      CurCoro.Data->CoroId = Call;
+    }
+  }
+
+  return RValue::get(Call);
+}

lib/CodeGen/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   Analysis
   BitReader
   BitWriter
   Core
+  Coroutines
   Coverage
   IPO
   IRReader
   InstCombine
   Instrumentation
   LTO
   Linker
   MC
add_clang_library(clangCodeGen
   CGCUDABuiltin.cpp
   CGCUDANV.cpp
   CGCUDARuntime.cpp
   CGCXX.cpp
   CGCXXABI.cpp
   CGCall.cpp
   CGClass.cpp
   CGCleanup.cpp
+  CGCoroutine.cpp
   CGDebugInfo.cpp
   CGDecl.cpp
   CGDeclCXX.cpp
   CGException.cpp
   CGExpr.cpp
   CGExprAgg.cpp
   CGExprCXX.cpp
   CGExprComplex.cpp

lib/CodeGen/CodeGenFunction.h

 class CGCXXABI;
 class BlockByrefHelpers;
 class BlockByrefInfo;
 class BlockFlags;
 class BlockFieldFlags;
 class RegionCodeGenTy;
 class TargetCodeGenInfo;
 struct OMPTaskDataTy;
+struct CGCoroData;
 
 /// The kind of evaluation to perform on values of a particular
 /// type.  Basically, is the code in CGExprScalar, CGExprComplex, or
 /// CGExprAgg?
 ///
 /// TODO: should vectors maybe be split out into their own thing?
 enum TypeEvaluationKind {
   TEK_Scalar,
public:
   /// non-closure context.
   const Decl *CurFuncDecl;
   /// CurCodeDecl - This is the inner-most code context, which includes blocks.
   const Decl *CurCodeDecl;
   const CGFunctionInfo *CurFnInfo;
   QualType FnRetTy;
   llvm::Function *CurFn;
 
+  // Holds coroutine data if the current function is a coroutine. We use a
+  // wrapper to manage its lifetime, so that we don't have to define CGCoroData
+  // in this header.
+  struct CGCoroInfo {
+    std::unique_ptr<CGCoroData> Data;
+    CGCoroInfo();
+    ~CGCoroInfo();
+  };
+  CGCoroInfo CurCoro;
+
   /// CurGD - The GlobalDecl for the current function being compiled.
   GlobalDecl CurGD;
 
   /// PrologueCleanupDepth - The cleanup depth enclosing all the
   /// cleanups associated with the parameters.
   EHScopeStack::stable_iterator PrologueCleanupDepth;
 
   /// ReturnBlock - Unified return block.
#endif
   void EmitAsmStmt(const AsmStmt &S);
 
   void EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S);
   void EmitObjCAtTryStmt(const ObjCAtTryStmt &S);
   void EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S);
   void EmitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt &S);
   void EmitObjCAutoreleasePoolStmt(const ObjCAutoreleasePoolStmt &S);
 
+  RValue EmitCoroutineIntrinsic(const CallExpr *E, unsigned int IID);
+
   void EnterCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock = false);
   void ExitCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock = false);
 
   void EmitCXXTryStmt(const CXXTryStmt &S);
   void EmitSEHTryStmt(const SEHTryStmt &S);
   void EmitSEHLeaveStmt(const SEHLeaveStmt &S);
   void EnterSEHTryStmt(const SEHTryStmt &S);
   void ExitSEHTryStmt(const SEHTryStmt &S);

test/CodeGenCoroutines/Inputs/coro.h

+void free(void *ptr);
+void *malloc(unsigned int);
+
+#define CORO_SUSPEND_IMPL(IsFinal)                                             \
+  switch (__builtin_coro_suspend(IsFinal)) {           \
+  case 0:                                                                      \
+    if (IsFinal)                                                               \
+      __builtin_trap();                                                        \
+    break;                                                                     \
+  case 1:                                                                      \
+    goto coro_Cleanup;                                                         \
+  default:                                                                     \
+    goto coro_Suspend;                                                         \
+  }
+
+#define CORO_SUSPEND() CORO_SUSPEND_IMPL(0)
+#define CORO_FINAL_SUSPEND() CORO_SUSPEND_IMPL(1)
+
+#define CORO_BEGIN(AllocFunc)                                                  \
+  void *coro_hdl =                                                             \
+      (__builtin_coro_id(0, 0, 0, 0),                                          \
+       __builtin_coro_begin((__builtin_coro_alloc()                            \
+                                 ? AllocFunc(__builtin_coro_size())            \
+                                 : (void *)0)));
+
+#define CORO_END(FreeFunc)                                                     \
+  coro_Cleanup : {                                                             \
+    void *coro_mem = __builtin_coro_free(coro_hdl);                            \
+    if (coro_mem)                                                              \
+      FreeFunc(coro_mem);                                                      \
+  }                                                                            \
+  coro_Suspend:                                                                \
+  __builtin_coro_end(0, 0);                                                    \
+  return coro_hdl;
+
+#define CORO_RESUME(hdl) __builtin_coro_resume(hdl)
+#define CORO_DESTROY(hdl) __builtin_coro_destroy(hdl)

test/CodeGenCoroutines/O2-coro.c

+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fcoroutines -emit-llvm %s -o - -O3 | FileCheck %s
+#include "Inputs/coro.h"
+void print(int);
+
+void* f() {
+  CORO_BEGIN(malloc);
+
+  for (int i = 0;; ++i) {
+    print(i);
+    CORO_SUSPEND();
+  }
+
+  CORO_END(free);
+}
+
+// CHECK-LABEL: @main
+int main() {
+  void* coro = f();
+  CORO_RESUME(coro);
+  CORO_RESUME(coro);
+  CORO_DESTROY(coro);
+// CHECK: call void @print(i32 0)
+// CHECK: call void @print(i32 1)
+// CHECK: call void @print(i32 2)
+}

test/CodeGenCoroutines/coro-builtins-err.c

+// RUN: %clang_cc1 -triple x86_64-pc-windows-msvc18.0.0 -fcoroutines -emit-llvm %s -o - -verify
+
+void f() {
+  __builtin_coro_alloc(); // expected-error {{this builtin expect that __builtin_coro_id}}
+  __builtin_coro_begin(0); // expected-error {{this builtin expect that __builtin_coro_id}}
+  __builtin_coro_free(0); // expected-error {{this builtin expect that __builtin_coro_id}}
+
+  __builtin_coro_id(32, 0, 0, 0);
+  __builtin_coro_id(32, 0, 0, 0); // expected-error {{only one __builtin_coro_id}}
+}

test/CodeGenCoroutines/coro-builtins.c

+// RUN: %clang_cc1 -triple x86_64-pc-windows-msvc18.0.0 -fcoroutines -emit-llvm %s -o - -disable-llvm-passes | FileCheck %s
+
+// CHECK-LABEL: f( 
+void f() {
+  // CHECK: %0 = call token @llvm.coro.id(i32 32, i8* null, i8* null, i8* null)
+  __builtin_coro_id(32, 0, 0, 0);
+  // CHECK-NEXT: %1 = call i1 @llvm.coro.alloc(token %0)
+  __builtin_coro_alloc();
+  // CHECK-NEXT: %2 = call i64 @llvm.coro.size.i64()
+  __builtin_coro_size();
+  // CHECK-NEXT: %3 = call i8* @llvm.coro.begin(token %0, i8* null)
+  __builtin_coro_begin(0);
+  // CHECK-NEXT: %4 = call i8* @llvm.coro.frame() 
+  __builtin_coro_frame();
+  // CHECK-NEXT: call void @llvm.coro.resume(i8* null)
+  __builtin_coro_resume(0);
+  // CHECK-NEXT: call void @llvm.coro.destroy(i8* null)
+  __builtin_coro_destroy(0);
+  // CHECK-NEXT: %5 = call i1 @llvm.coro.done(i8* null)
+  __builtin_coro_done(0);
+  // CHECK-NEXT: %6 = call i8* @llvm.coro.promise(i8* null, i32 32, i1 false)
+  __builtin_coro_promise(0, 32, 0);
+  // CHECK-NEXT: %7 = call i8* @llvm.coro.free(token %0, i8* null)
+  __builtin_coro_free(0);
+  // CHECK-NEXT: call void @llvm.coro.end(i8* null, i1 false)
+  __builtin_coro_end(0, 0);
+  // CHECK-NEXT: %8 = call i8 @llvm.coro.suspend(token none, i1 false)
+  __builtin_coro_suspend(0);
+  // CHECK-NEXT: %9 = call i1 @llvm.coro.param(i8* null, i8* null)
+  __builtin_coro_param(0, 0);
+}