GorNishanov updated this revision to Diff 91497.
GorNishanov added a comment.
Implemented review feedback: const char * => StringRef in buildSuspendSuffixStr
https://reviews.llvm.org/D30809
Files:
lib/CodeGen/CGCoroutine.cpp
lib/CodeGen/CGExprAgg.cpp
lib/CodeGen/CGExprScalar.cpp
lib/CodeGen/CodeGenFunction.h
test/CodeGenCoroutines/coro-await.cpp
Index: test/CodeGenCoroutines/coro-await.cpp
===================================================================
--- /dev/null
+++ test/CodeGenCoroutines/coro-await.cpp
@@ -0,0 +1,134 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fcoroutines-ts -std=c++14 -emit-llvm %s -o - -disable-llvm-passes | FileCheck %s
+
+namespace std {
+namespace experimental {
+template <typename... T>
+struct coroutine_traits;
+
+template <typename Promise = void> struct coroutine_handle;
+
+template <>
+struct coroutine_handle<void> {
+ void *ptr;
+ static coroutine_handle from_address(void *);
+};
+
+template <typename Promise>
+struct coroutine_handle : coroutine_handle<> {
+ static coroutine_handle from_address(void *);
+};
+
+}
+}
+
+struct suspend_always {
+ int stuff;
+ bool await_ready();
+ void await_suspend(std::experimental::coroutine_handle<>);
+ void await_resume();
+};
+
+template<>
+struct std::experimental::coroutine_traits<void> {
+ struct promise_type {
+ void get_return_object();
+ suspend_always initial_suspend();
+ suspend_always final_suspend();
+ void return_void();
+ };
+};
+
+// CHECK-LABEL: f0(
+extern "C" void f0() {
+
+ co_await suspend_always{};
+ // See if we need to suspend:
+ // --------------------------
+ // CHECK: %[[READY:.+]] = call zeroext i1 @_ZN14suspend_always11await_readyEv(%struct.suspend_always* %[[AWAITABLE:.+]])
+ // CHECK: br i1 %[[READY]], label %[[READY_BB:.+]], label %[[SUSPEND_BB:.+]]
+
+ // If we are suspending:
+ // ---------------------
+ // CHECK: [[SUSPEND_BB]]:
+ // CHECK: %[[SUSPEND_ID:.+]] = call token @llvm.coro.save(
+ // ---------------------------
+ // Build the coroutine handle and pass it to await_suspend
+ // ---------------------------
+ // CHECK: %[[FRAME:.+]] = call i8* @llvm.coro.frame()
+ // CHECK: call i8* @_ZNSt12experimental16coroutine_handleINS_16coroutine_traitsIJvEE12promise_typeEE12from_addressEPv(i8* %[[FRAME]])
+ // ... many lines of code to coerce coroutine_handle into an i8* scalar
+ // CHECK: %[[CH:.+]] = load i8*, i8** %{{.+}}
+ // CHECK: call void @_ZN14suspend_always13await_suspendENSt12experimental16coroutine_handleIvEE(%struct.suspend_always* %[[AWAITABLE]], i8* %[[CH]])
+ // -------------------------
+ // Generate a suspend point:
+ // -------------------------
+ // CHECK: %[[OUTCOME:.+]] = call i8 @llvm.coro.suspend(token %[[SUSPEND_ID]], i1 false)
+ // CHECK: switch i8 %[[OUTCOME]], label %[[RET_BB:.+]] [
+ // CHECK: i8 0, label %[[READY_BB]]
+ // CHECK: i8 1, label %[[CLEANUP_BB:.+]]
+ // CHECK: ]
+
+ // Cleanup code goes here:
+ // -----------------------
+ // CHECK: [[CLEANUP_BB]]:
+
+ // When coroutine is resumed, call await_resume
+ // --------------------------
+ // CHECK: [[READY_BB]]:
+ // CHECK: call void @_ZN14suspend_always12await_resumeEv(%struct.suspend_always* %[[AWAITABLE]])
+}
+
+struct suspend_maybe {
+ float stuff;
+ ~suspend_maybe();
+ bool await_ready();
+ bool await_suspend(std::experimental::coroutine_handle<>);
+ void await_resume();
+};
+
+
+template<>
+struct std::experimental::coroutine_traits<void,int> {
+ struct promise_type {
+ void get_return_object();
+ suspend_always initial_suspend();
+ suspend_always final_suspend();
+ void return_void();
+ suspend_maybe yield_value(int);
+ };
+};
+
+// CHECK-LABEL: f1(
+extern "C" void f1(int) {
+ co_yield 42;
+ // CHECK: %[[PROMISE:.+]] = alloca %"struct.std::experimental::coroutine_traits<void, int>::promise_type"
+ // CHECK: call void @_ZNSt12experimental16coroutine_traitsIJviEE12promise_type11yield_valueEi(%struct.suspend_maybe* sret %[[AWAITER:.+]], %"struct.std::experimental::coroutine_traits<void, int>::promise_type"* %[[PROMISE]], i32 42)
+
+ // See if we need to suspend:
+ // --------------------------
+ // CHECK: %[[READY:.+]] = call zeroext i1 @_ZN13suspend_maybe11await_readyEv(%struct.suspend_maybe* %[[AWAITABLE]])
+ // CHECK: br i1 %[[READY]], label %[[READY_BB:.+]], label %[[SUSPEND_BB:.+]]
+
+ // If we are suspending:
+ // ---------------------
+ // CHECK: [[SUSPEND_BB]]:
+ // CHECK: %[[SUSPEND_ID:.+]] = call token @llvm.coro.save(
+ // ---------------------------
+ // Build the coroutine handle and pass it to await_suspend
+ // ---------------------------
+ // CHECK: %[[FRAME:.+]] = call i8* @llvm.coro.frame()
+ // CHECK: call i8* @_ZNSt12experimental16coroutine_handleINS_16coroutine_traitsIJviEE12promise_typeEE12from_addressEPv(i8* %[[FRAME]])
+ // ... many lines of code to coerce coroutine_handle into an i8* scalar
+ // CHECK: %[[CH:.+]] = load i8*, i8** %{{.+}}
+ // CHECK: %[[YES:.+]] = call zeroext i1 @_ZN13suspend_maybe13await_suspendENSt12experimental16coroutine_handleIvEE(%struct.suspend_maybe* %[[AWAITABLE]], i8* %[[CH]])
+ // -------------------------------------------
+ // See if await_suspend decided not to suspend
+ // -------------------------------------------
+ // CHECK: br i1 %[[YES]], label %[[SUSPEND_PLEASE:.+]], label %[[READY_BB]]
+
+ // CHECK: [[SUSPEND_PLEASE]]:
+ // CHECK: call i8 @llvm.coro.suspend(token %[[SUSPEND_ID]], i1 false)
+
+ // CHECK: [[READY_BB]]:
+ // CHECK: call void @_ZN13suspend_maybe12await_resumeEv(%struct.suspend_maybe* %[[AWAITABLE]])
+}
Index: lib/CodeGen/CodeGenFunction.h
===================================================================
--- lib/CodeGen/CodeGenFunction.h
+++ lib/CodeGen/CodeGenFunction.h
@@ -2511,6 +2511,10 @@
void EmitCoroutineBody(const CoroutineBodyStmt &S);
void EmitCoreturnStmt(const CoreturnStmt &S);
+ llvm::Value *EmitCoawaitExpr(const CoawaitExpr &E,
+ ReturnValueSlot ReturnValue = ReturnValueSlot());
+ llvm::Value *EmitCoyieldExpr(const CoyieldExpr &E,
+ ReturnValueSlot ReturnValue = ReturnValueSlot());
RValue EmitCoroutineIntrinsic(const CallExpr *E, unsigned int IID);
void EnterCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock = false);
Index: lib/CodeGen/CGExprScalar.cpp
===================================================================
--- lib/CodeGen/CGExprScalar.cpp
+++ lib/CodeGen/CGExprScalar.cpp
@@ -276,6 +276,15 @@
Value *VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
return Visit(GE->getResultExpr());
}
+ Value *VisitCoawaitExpr(CoawaitExpr *S) {
+ return CGF.EmitCoawaitExpr(*S);
+ }
+ Value *VisitCoyieldExpr(CoyieldExpr *S) {
+ return CGF.EmitCoyieldExpr(*S);
+ }
+ Value *VisitUnaryCoawait(const UnaryOperator *E) {
+ return Visit(E->getSubExpr());
+ }
// Leaves.
Value *VisitIntegerLiteral(const IntegerLiteral *E) {
@@ -1671,7 +1680,7 @@
}
case CK_IntToOCLSampler:
- return CGF.CGM.createOpenCLIntToSamplerConversion(E, CGF);
+ return CGF.CGM.createOpenCLIntToSamplerConversion(E, CGF);
} // end of switch
Index: lib/CodeGen/CGExprAgg.cpp
===================================================================
--- lib/CodeGen/CGExprAgg.cpp
+++ lib/CodeGen/CGExprAgg.cpp
@@ -111,6 +111,13 @@
void VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
Visit(GE->getResultExpr());
}
+ void VisitCoawaitExpr(CoawaitExpr *E) {
+ CGF.EmitCoawaitExpr(*E, getReturnValueSlot());
+ }
+ void VisitCoyieldExpr(CoyieldExpr *E) {
+ CGF.EmitCoyieldExpr(*E, getReturnValueSlot());
+ }
+ void VisitUnaryCoawait(UnaryOperator *E) { Visit(E->getSubExpr()); }
void VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); }
void VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) {
return Visit(E->getReplacement());
Index: lib/CodeGen/CGCoroutine.cpp
===================================================================
--- lib/CodeGen/CGCoroutine.cpp
+++ lib/CodeGen/CGCoroutine.cpp
@@ -12,20 +12,33 @@
//===----------------------------------------------------------------------===//
#include "CodeGenFunction.h"
+#include "llvm/ADT/ScopeExit.h"
#include "clang/AST/StmtCXX.h"
using namespace clang;
using namespace CodeGen;
+using llvm::Value;
+using llvm::BasicBlock;
+
+namespace {
+enum class AwaitKind { Init, Normal, Yield, Final };
+}
+
namespace clang {
namespace CodeGen {
struct CGCoroData {
+ AwaitKind CurrentAwaitKind = AwaitKind::Init;
+ llvm::BasicBlock *SuspendBB = nullptr;
+ CodeGenFunction::JumpDest CleanupJD;
// Stores the jump destination just before the final suspend. Coreturn
// statements jumps to this point after calling return_xxx promise member.
CodeGenFunction::JumpDest FinalJD;
+ unsigned AwaitNum = 0;
+ unsigned YieldNum = 0;
unsigned CoreturnCount = 0;
// Stores the llvm.coro.id emitted in the function so that we can supply it
@@ -66,6 +79,142 @@
CurCoro.Data->CoroIdExpr = CoroIdExpr;
}
+// Synthesize a pretty name for a suspend point.
+static SmallString<32> buildSuspendSuffixStr(CGCoroData &Coro, AwaitKind Kind) {
+ unsigned No = 0;
+ StringRef AwaitKindStr = 0;
+ switch (Kind) {
+ case AwaitKind::Init:
+ AwaitKindStr = "init";
+ break;
+ case AwaitKind::Final:
+ AwaitKindStr = "final";
+ break;
+ case AwaitKind::Normal:
+ AwaitKindStr = "await";
+ No = ++Coro.AwaitNum;
+ break;
+ case AwaitKind::Yield:
+ AwaitKindStr = "yield";
+ No = ++Coro.YieldNum;
+ break;
+ }
+ SmallString<32> Suffix(AwaitKindStr);
+ if (No > 1) {
+ Twine(No).toVector(Suffix);
+ }
+ return Suffix;
+}
+
+// Emit suspend expression which roughly looks like:
+//
+// auto && x = CommonExpr();
+// if (!x.await_ready()) {
+// llvm_coro_save();
+// x.await_suspend(...); (*)
+// llvm_coro_suspend(); (**)
+// }
+// x.await_resume();
+//
+// where the result of the entire expression is the result of x.await_resume()
+//
+// (*) If x.await_suspend return type is bool, it allows to veto a suspend:
+// if (x.await_suspend(...))
+// llvm_coro_suspend();
+//
+// (**) llvm_coro_suspend() encodes three possible continuations as
+// a switch instruction:
+//
+// %where-to = call i8 @llvm.coro.suspend(...)
+// switch i8 %where-to, label %coro.ret [ ; jump to epilogue to suspend
+// i8 0, label %yield.ready ; go here when resumed
+// i8 1, label %yield.cleanup ; go here when destroyed
+// ]
+//
+// See llvm's docs/Coroutines.rst for more details.
+//
+static Value *emitSuspendExpression(CodeGenFunction &CGF, CGCoroData &Coro,
+ CoroutineSuspendExpr const &S,
+ AwaitKind Kind,
+ ReturnValueSlot ReturnValue) {
+ auto &Builder = CGF.Builder;
+ const bool IsFinalSuspend = Kind == AwaitKind::Final;
+ auto Suffix = buildSuspendSuffixStr(Coro, Kind);
+
+ auto *E = S.getCommonExpr();
+ if (auto *UO = dyn_cast<UnaryOperator>(E))
+ if (UO->getOpcode() == UO_Coawait)
+ E = UO->getSubExpr();
+
+ auto Binder =
+ CodeGenFunction::OpaqueValueMappingData::bind(CGF, S.getOpaqueValue(), E);
+ auto UnbindOnExit = llvm::make_scope_exit([&] { Binder.unbind(CGF); });
+
+ BasicBlock *ReadyBlock = CGF.createBasicBlock(Suffix + Twine(".ready"));
+ BasicBlock *SuspendBlock = CGF.createBasicBlock(Suffix + Twine(".suspend"));
+ BasicBlock *CleanupBlock = CGF.createBasicBlock(Suffix + Twine(".cleanup"));
+
+ CGF.EmitBranchOnBoolExpr(S.getReadyExpr(), ReadyBlock, SuspendBlock, 0);
+ CGF.EmitBlock(SuspendBlock);
+
+ llvm::Function *CoroSave = CGF.CGM.getIntrinsic(llvm::Intrinsic::coro_save);
+ auto *NullPtr = llvm::ConstantPointerNull::get(CGF.CGM.Int8PtrTy);
+ auto *SaveCall = Builder.CreateCall(CoroSave, {NullPtr});
+
+ auto *SuspendRet = CGF.EmitScalarExpr(S.getSuspendExpr());
+ if (SuspendRet != nullptr) {
+ assert(SuspendRet->getType()->isIntegerTy(1) &&
+ "Sema should have already checked that it is void or bool");
+ BasicBlock *RealSuspendBlock =
+ CGF.createBasicBlock(Suffix + Twine(".suspend.bool"));
+ CGF.Builder.CreateCondBr(SuspendRet, RealSuspendBlock, ReadyBlock);
+ SuspendBlock = RealSuspendBlock;
+ CGF.EmitBlock(RealSuspendBlock);
+ }
+
+ llvm::Function *CoroSuspend =
+ CGF.CGM.getIntrinsic(llvm::Intrinsic::coro_suspend);
+ auto *SuspendResult = Builder.CreateCall(
+ CoroSuspend, {SaveCall, Builder.getInt1(IsFinalSuspend)});
+ auto *Switch = Builder.CreateSwitch(SuspendResult, Coro.SuspendBB, 2);
+ Switch->addCase(Builder.getInt8(0), ReadyBlock);
+ Switch->addCase(Builder.getInt8(1), CleanupBlock);
+
+ CGF.EmitBlock(CleanupBlock);
+
+ CGF.EmitBranchThroughCleanup(Coro.CleanupJD);
+
+ // Emit await_resume expression.
+ CGF.EmitBlock(ReadyBlock);
+ QualType Type = S.getResumeExpr()->getType();
+ switch (CGF.getEvaluationKind(Type)) {
+ case TEK_Scalar:
+ return CGF.EmitScalarExpr(S.getResumeExpr());
+ case TEK_Aggregate:
+ CGF.EmitAggExpr(S.getResumeExpr(),
+ AggValueSlot::forAddr(ReturnValue.getValue(), Qualifiers(),
+ AggValueSlot::IsDestructed,
+ AggValueSlot::DoesNotNeedGCBarriers,
+ AggValueSlot::IsNotAliased));
+ break;
+ case TEK_Complex:
+ CGF.CGM.ErrorUnsupported(S.getResumeExpr(), "_Complex await expression");
+ break;
+ }
+ return nullptr;
+}
+
+llvm::Value *CodeGenFunction::EmitCoawaitExpr(const CoawaitExpr &E,
+ ReturnValueSlot ReturnValue) {
+ return emitSuspendExpression(*this, *CurCoro.Data, E,
+ CurCoro.Data->CurrentAwaitKind, ReturnValue);
+}
+llvm::Value *CodeGenFunction::EmitCoyieldExpr(const CoyieldExpr &E,
+ ReturnValueSlot ReturnValue) {
+ return emitSuspendExpression(*this, *CurCoro.Data, E, AwaitKind::Yield,
+ ReturnValue);
+}
+
void CodeGenFunction::EmitCoreturnStmt(CoreturnStmt const &S) {
++CurCoro.Data->CoreturnCount;
EmitStmt(S.getPromiseCall());
@@ -78,18 +227,21 @@
unsigned NewAlign = TI.getNewAlign() / TI.getCharWidth();
auto *FinalBB = createBasicBlock("coro.final");
+ auto *RetBB = createBasicBlock("coro.ret");
auto *CoroId = Builder.CreateCall(
CGM.getIntrinsic(llvm::Intrinsic::coro_id),
{Builder.getInt32(NewAlign), NullPtr, NullPtr, NullPtr});
createCoroData(*this, CurCoro, CoroId);
+ CurCoro.Data->SuspendBB = RetBB;
EmitScalarExpr(S.getAllocate());
// FIXME: Setup cleanup scopes.
EmitStmt(S.getPromiseDeclStmt());
+ CurCoro.Data->CleanupJD = getJumpDestInCurrentScope(RetBB);
CurCoro.Data->FinalJD = getJumpDestInCurrentScope(FinalBB);
// FIXME: Emit initial suspend and more before the body.
@@ -105,6 +257,8 @@
}
EmitStmt(S.getDeallocate());
+ EmitBlock(RetBB);
+
// FIXME: Emit return for the coroutine return object.
}
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