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Cherry-pick coro async mangling and single predecessor phi fix #3074

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Merged
merged 4 commits into from
Jul 7, 2021
Merged

Cherry-pick coro async mangling and single predecessor phi fix #3074

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0446a4a
[coro async] Use swift mangling for resume functions
aschwaighofer Jul 6, 2021
8ba3b7a
Fix coro lowering of single predecessor phis
aschwaighofer Apr 1, 2021
6e250ca
[coro async] Add support for specifying which parameter is swiftself in
aschwaighofer Jun 30, 2021
7438d49
Move code to proper switch
aschwaighofer Jul 6, 2021
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22 changes: 22 additions & 0 deletions llvm/lib/Transforms/Coroutines/CoroFrame.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1839,6 +1839,24 @@ static void rewritePHIsForCleanupPad(BasicBlock *CleanupPadBB,
}
}

static void cleanupSinglePredPHIs(Function &F) {
SmallVector<PHINode *, 32> Worklist;
for (auto &BB : F) {
for (auto &Phi : BB.phis()) {
if (Phi.getNumIncomingValues() == 1) {
Worklist.push_back(&Phi);
} else
break;
}
}
while (!Worklist.empty()) {
auto *Phi = Worklist.back();
Worklist.pop_back();
auto *OriginalValue = Phi->getIncomingValue(0);
Phi->replaceAllUsesWith(OriginalValue);
}
}

static void rewritePHIs(BasicBlock &BB) {
// For every incoming edge we will create a block holding all
// incoming values in a single PHI nodes.
Expand Down Expand Up @@ -2602,6 +2620,10 @@ void coro::buildCoroutineFrame(Function &F, Shape &Shape) {
}
}

// Later code makes structural assumptions about single predecessors phis e.g
// that they are not live accross a suspend point.
cleanupSinglePredPHIs(F);

// Transforms multi-edge PHI Nodes, so that any value feeding into a PHI will
// never has its definition separated from the PHI by the suspend point.
rewritePHIs(F);
Expand Down
50 changes: 38 additions & 12 deletions llvm/lib/Transforms/Coroutines/CoroSplit.cpp
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Expand Up @@ -765,8 +765,8 @@ Value *CoroCloner::deriveNewFramePointer() {
// context header.
case coro::ABI::Async: {
auto *ActiveAsyncSuspend = cast<CoroSuspendAsyncInst>(ActiveSuspend);
auto *CalleeContext =
NewF->getArg(ActiveAsyncSuspend->getStorageArgumentIndex());
auto ContextIdx = ActiveAsyncSuspend->getStorageArgumentIndex() & 0xff;
auto *CalleeContext = NewF->getArg(ContextIdx);
auto *FramePtrTy = Shape.FrameTy->getPointerTo();
auto *ProjectionFunc =
ActiveAsyncSuspend->getAsyncContextProjectionFunction();
Expand Down Expand Up @@ -827,6 +827,13 @@ static void addAsyncContextAttrs(AttributeList &Attrs, LLVMContext &Context,
Attrs = Attrs.addParamAttributes(Context, ParamIndex, ParamAttrs);
}

static void addSwiftSelfAttrs(AttributeList &Attrs, LLVMContext &Context,
unsigned ParamIndex) {
AttrBuilder ParamAttrs;
ParamAttrs.addAttribute(Attribute::SwiftSelf);
Attrs = Attrs.addParamAttributes(Context, ParamIndex, ParamAttrs);
}

/// Clone the body of the original function into a resume function of
/// some sort.
void CoroCloner::create() {
Expand Down Expand Up @@ -906,10 +913,21 @@ void CoroCloner::create() {
Shape.FrameSize, Shape.FrameAlign);
break;
case coro::ABI::Async: {
auto *ActiveAsyncSuspend = cast<CoroSuspendAsyncInst>(ActiveSuspend);
if (OrigF.hasParamAttribute(Shape.AsyncLowering.ContextArgNo,
Attribute::SwiftAsync)) {
addAsyncContextAttrs(NewAttrs, Context, Shape.AsyncLowering.ContextArgNo);
uint32_t ArgAttributeIndices =
ActiveAsyncSuspend->getStorageArgumentIndex();
auto ContextArgIndex = ArgAttributeIndices & 0xff;
addAsyncContextAttrs(NewAttrs, Context, ContextArgIndex);

// `swiftasync` must preceed `swiftself` so 0 is not a valid index for
// `swiftself`.
auto SwiftSelfIndex = ArgAttributeIndices >> 8;
if (SwiftSelfIndex)
addSwiftSelfAttrs(NewAttrs, Context, SwiftSelfIndex);
}

// Transfer the original function's attributes.
auto FnAttrs = OrigF.getAttributes().getFnAttributes();
NewAttrs =
Expand Down Expand Up @@ -949,16 +967,9 @@ void CoroCloner::create() {
// followed by a return.
// Don't change returns to unreachable because that will trip up the verifier.
// These returns should be unreachable from the clone.
case coro::ABI::Async: {
auto *ActiveAsyncSuspend = cast<CoroSuspendAsyncInst>(ActiveSuspend);
if (OrigF.hasParamAttribute(Shape.AsyncLowering.ContextArgNo,
Attribute::SwiftAsync)) {
auto ContextArgIndex = ActiveAsyncSuspend->getStorageArgumentIndex();
addAsyncContextAttrs(NewAttrs, Context, ContextArgIndex);
}
case coro::ABI::Async:
break;
}
}

NewF->setAttributes(NewAttrs);
NewF->setCallingConv(Shape.getResumeFunctionCC());
Expand Down Expand Up @@ -1600,8 +1611,23 @@ static void splitAsyncCoroutine(Function &F, coro::Shape &Shape,
auto *Suspend = cast<CoroSuspendAsyncInst>(Shape.CoroSuspends[Idx]);

// Create the clone declaration.
auto ResumeNameSuffix = ".resume.";
auto ProjectionFunctionName =
Suspend->getAsyncContextProjectionFunction()->getName();
bool UseSwiftMangling = false;
if (ProjectionFunctionName.equals("__swift_async_resume_project_context")) {
ResumeNameSuffix = "TQ";
UseSwiftMangling = true;
} else if (ProjectionFunctionName.equals(
"__swift_async_resume_get_context")) {
ResumeNameSuffix = "TY";
UseSwiftMangling = true;
}
auto *Continuation = createCloneDeclaration(
F, Shape, ".resume." + Twine(Idx), NextF, Suspend);
F, Shape,
UseSwiftMangling ? ResumeNameSuffix + Twine(Idx) + "_"
: ResumeNameSuffix + Twine(Idx),
NextF, Suspend);
Clones.push_back(Continuation);

// Insert a branch to a new return block immediately before the suspend
Expand Down
196 changes: 196 additions & 0 deletions llvm/test/Transforms/Coroutines/coro-async-phi.ll
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Original file line number Diff line number Diff line change
@@ -0,0 +1,196 @@
; RUN: opt < %s -enable-coroutines -O0 -S | FileCheck --check-prefixes=CHECK %s
; RUN: opt < %s -enable-coroutines -passes='default<O0>' -S | FileCheck --check-prefixes=CHECK %s

%swift.async_func_pointer = type <{ i32, i32 }>
%swift.context = type { %swift.context*, void (%swift.context*)*, i64 }
%T10RR13AC = type <{ %swift.refcounted, %swift.defaultactor }>
%swift.refcounted = type { %swift.type*, i64 }
%swift.type = type { i64 }
%swift.defaultactor = type { [10 x i8*] }
%swift.bridge = type opaque
%swift.error = type opaque
%swift.executor = type {}

@repoTU = hidden global %swift.async_func_pointer <{ i32 trunc (i64 sub (i64 ptrtoint (void (%swift.context*, i64, i64, %T10RR13AC*)* @repo to i64), i64 ptrtoint (%swift.async_func_pointer* @repoTU to i64)) to i32), i32 20 }>, section "__TEXT,__const", align 8

declare void @use(i8*)

; This used to crash.
; CHECK: repo
define hidden swifttailcc void @repo(%swift.context* swiftasync %arg, i64 %arg1, i64 %arg2, %T10RR13AC* swiftself %arg3) #0 {
entry:
%i = alloca %swift.context*, align 8
%i11 = call token @llvm.coro.id.async(i32 20, i32 16, i32 0, i8* bitcast (%swift.async_func_pointer* @repoTU to i8*))
%i12 = call i8* @llvm.coro.begin(token %i11, i8* null)
%i18 = call i8* @llvm.coro.async.resume()
call void @use(i8* %i18)
%i21 = call { i8* } (i32, i8*, i8*, ...) @llvm.coro.suspend.async.sl_p0i8s(i32 0, i8* %i18, i8* bitcast (i8* (i8*)* @__swift_async_resume_get_context to i8*), i8* bitcast (void (i8*, %swift.executor*, %swift.context*)* @__swift_suspend_point to i8*), i8* %i18, %swift.executor* null, %swift.context* null)
%i22 = extractvalue { i8* } %i21, 0
%i23 = call i8* @__swift_async_resume_get_context(i8* %i22)
%i28 = icmp eq i64 %arg2, 0
br i1 %i28, label %bb126, label %bb

bb: ; preds = %entry
%i29 = inttoptr i64 %arg2 to %swift.bridge*
br label %bb30

bb30: ; preds = %bb
%i31 = phi i64 [ %arg1, %bb ]
%i32 = phi %swift.bridge* [ %i29, %bb ]
%i35 = ptrtoint %swift.bridge* %i32 to i64
%i36 = bitcast %T10RR13AC* %arg3 to %swift.type**
%i37 = load %swift.type*, %swift.type** %i36, align 8
%i38 = bitcast %swift.type* %i37 to void (%swift.context*, i64, i64, %T10RR13AC*)**
%i39 = getelementptr inbounds void (%swift.context*, i64, i64, %T10RR13AC*)*, void (%swift.context*, i64, i64, %T10RR13AC*)** %i38, i64 11
%i40 = load void (%swift.context*, i64, i64, %T10RR13AC*)*, void (%swift.context*, i64, i64, %T10RR13AC*)** %i39, align 8
%i41 = bitcast void (%swift.context*, i64, i64, %T10RR13AC*)* %i40 to %swift.async_func_pointer*
%i42 = getelementptr inbounds %swift.async_func_pointer, %swift.async_func_pointer* %i41, i32 0, i32 0
%i43 = load i32, i32* %i42, align 8
%i44 = sext i32 %i43 to i64
%i45 = ptrtoint i32* %i42 to i64
%i46 = add i64 %i45, %i44
%i47 = inttoptr i64 %i46 to i8*
%i48 = bitcast i8* %i47 to void (%swift.context*, i64, i64, %T10RR13AC*)*
%i52 = call swiftcc i8* @swift_task_alloc(i64 24) #1
%i53 = bitcast i8* %i52 to <{ %swift.context*, void (%swift.context*)*, i32 }>*
%i54 = load %swift.context*, %swift.context** %i, align 8
%i55 = getelementptr inbounds <{ %swift.context*, void (%swift.context*)*, i32 }>, <{ %swift.context*, void (%swift.context*)*, i32 }>* %i53, i32 0, i32 0
store %swift.context* %i54, %swift.context** %i55, align 8
%i56 = call i8* @llvm.coro.async.resume()
call void @use(i8* %i56)
%i57 = bitcast i8* %i56 to void (%swift.context*)*
%i58 = getelementptr inbounds <{ %swift.context*, void (%swift.context*)*, i32 }>, <{ %swift.context*, void (%swift.context*)*, i32 }>* %i53, i32 0, i32 1
store void (%swift.context*)* %i57, void (%swift.context*)** %i58, align 8
%i59 = bitcast i8* %i52 to %swift.context*
%i60 = bitcast void (%swift.context*, i64, i64, %T10RR13AC*)* %i48 to i8*
%i61 = call { i8*, %swift.error* } (i32, i8*, i8*, ...) @llvm.coro.suspend.async.sl_p0i8p0s_swift.errorss(i32 256, i8* %i56, i8* bitcast (i8* (i8*)* @__swift_async_resume_project_context to i8*), i8* bitcast (void (i8*, %swift.context*, i64, i64, %T10RR13AC*)* @__swift_suspend_dispatch_4 to i8*), i8* %i60, %swift.context* %i59, i64 %i31, i64 0, %T10RR13AC* %arg3)
%i62 = extractvalue { i8*, %swift.error* } %i61, 0
%i63 = call i8* @__swift_async_resume_project_context(i8* %i62)
%i64 = bitcast i8* %i63 to %swift.context*
store %swift.context* %i64, %swift.context** %i, align 8
%i65 = extractvalue { i8*, %swift.error* } %i61, 1
call swiftcc void @swift_task_dealloc(i8* %i52) #1
br i1 %i28, label %bb126, label %bb68

bb68: ; preds = %bb30
%i69 = call i8* @llvm.coro.async.resume()
call void @use(i8* %i69)
%i70 = load %swift.context*, %swift.context** %i, align 8
%i71 = call { i8* } (i32, i8*, i8*, ...) @llvm.coro.suspend.async.sl_p0i8s(i32 0, i8* %i69, i8* bitcast (i8* (i8*)* @__swift_async_resume_get_context to i8*), i8* bitcast (void (i8*, %swift.executor*, %swift.context*)* @__swift_suspend_point to i8*), i8* %i69, %swift.executor* null, %swift.context* %i70)
%i77 = ptrtoint %swift.bridge* %i32 to i64
%i78 = bitcast %T10RR13AC* %arg3 to %swift.type**
%i79 = load %swift.type*, %swift.type** %i78, align 8
%i80 = bitcast %swift.type* %i79 to void (%swift.context*, i64, i64, %T10RR13AC*)**
%i81 = getelementptr inbounds void (%swift.context*, i64, i64, %T10RR13AC*)*, void (%swift.context*, i64, i64, %T10RR13AC*)** %i80, i64 11
%i82 = load void (%swift.context*, i64, i64, %T10RR13AC*)*, void (%swift.context*, i64, i64, %T10RR13AC*)** %i81, align 8
%i83 = bitcast void (%swift.context*, i64, i64, %T10RR13AC*)* %i82 to %swift.async_func_pointer*
%i84 = getelementptr inbounds %swift.async_func_pointer, %swift.async_func_pointer* %i83, i32 0, i32 0
%i85 = load i32, i32* %i84, align 8
%i86 = sext i32 %i85 to i64
%i87 = ptrtoint i32* %i84 to i64
%i88 = add i64 %i87, %i86
%i89 = inttoptr i64 %i88 to i8*
%i90 = bitcast i8* %i89 to void (%swift.context*, i64, i64, %T10RR13AC*)*
%i94 = call swiftcc i8* @swift_task_alloc(i64 24) #1
%i98 = call i8* @llvm.coro.async.resume()
call void @use(i8* %i98)
%i102 = bitcast void (%swift.context*, i64, i64, %T10RR13AC*)* %i90 to i8*
%i103 = call { i8*, %swift.error* } (i32, i8*, i8*, ...) @llvm.coro.suspend.async.sl_p0i8p0s_swift.errorss(i32 256, i8* %i98, i8* bitcast (i8* (i8*)* @__swift_async_resume_project_context to i8*), i8* bitcast (void (i8*, %swift.context*, i64, i64, %T10RR13AC*)* @__swift_suspend_dispatch_4.1 to i8*), i8* %i102, %swift.context* null, i64 %i31, i64 0, %T10RR13AC* %arg3)
call swiftcc void @swift_task_dealloc(i8* %i94) #1
br label %bb126

bb126:
%i162 = call i1 (i8*, i1, ...) @llvm.coro.end.async(i8* %i12, i1 false, void (i8*, %swift.context*, %swift.error*)* @__swift_suspend_dispatch_2, i8* bitcast (void (%swift.context*, %swift.error*)* @doIt to i8*), %swift.context* null, %swift.error* null)
unreachable
}

; Function Attrs: nounwind
declare token @llvm.coro.id.async(i32, i32, i32, i8*) #1

; Function Attrs: nounwind
declare i8* @llvm.coro.begin(token, i8* writeonly) #1

; Function Attrs: argmemonly nofree nosync nounwind willreturn writeonly
declare void @llvm.memset.p0i8.i64(i8* nocapture writeonly, i8, i64, i1 immarg) #3

; Function Attrs: nounwind
declare i8* @llvm.coro.async.resume() #1

; Function Attrs: noinline
define linkonce_odr hidden i8* @__swift_async_resume_get_context(i8* %arg) #4 {
entry:
ret i8* %arg
}

; Function Attrs: nounwind
declare extern_weak swifttailcc void @swift_task_switch(%swift.context*, i8*, %swift.executor*) #1

; Function Attrs: nounwind
define internal swifttailcc void @__swift_suspend_point(i8* %arg, %swift.executor* %arg1, %swift.context* %arg2) #1 {
entry:
musttail call swifttailcc void @swift_task_switch(%swift.context* swiftasync %arg2, i8* %arg, %swift.executor* %arg1) #1
ret void
}

; Function Attrs: nounwind
declare { i8* } @llvm.coro.suspend.async.sl_p0i8s(i32, i8*, i8*, ...) #1

; Function Attrs: nounwind
declare i1 @llvm.coro.end.async(i8*, i1, ...) #1

; Function Attrs: argmemonly nounwind
declare extern_weak swiftcc i8* @swift_task_alloc(i64) #5

; Function Attrs: nounwind readnone
declare i8** @llvm.swift.async.context.addr() #6

; Function Attrs: alwaysinline nounwind
define linkonce_odr hidden i8* @__swift_async_resume_project_context(i8* %arg) #7 {
entry:
%i = bitcast i8* %arg to i8**
%i1 = load i8*, i8** %i, align 8
%i2 = call i8** @llvm.swift.async.context.addr()
store i8* %i1, i8** %i2, align 8
ret i8* %i1
}

; Function Attrs: nounwind
declare { i8*, %swift.error* } @llvm.coro.suspend.async.sl_p0i8p0s_swift.errorss(i32, i8*, i8*, ...) #1

; Function Attrs: argmemonly nounwind
declare extern_weak swiftcc void @swift_task_dealloc(i8*) #5

; Function Attrs: nounwind
define internal swifttailcc void @__swift_suspend_dispatch_4(i8* %arg, %swift.context* %arg1, i64 %arg2, i64 %arg3, %T10RR13AC* %arg4) #1 {
entry:
%i = bitcast i8* %arg to void (%swift.context*, i64, i64, %T10RR13AC*)*
musttail call swifttailcc void %i(%swift.context* swiftasync %arg1, i64 %arg2, i64 %arg3, %T10RR13AC* swiftself %arg4)
ret void
}

declare swifttailcc void @doIt(%swift.context* swiftasync %arg1, %swift.error* swiftself %arg2)

; Function Attrs: nounwind
define internal swifttailcc void @__swift_suspend_dispatch_2(i8* %arg, %swift.context* %arg1, %swift.error* %arg2) #1 {
entry:
%i = bitcast i8* %arg to void (%swift.context*, %swift.error*)*
musttail call swifttailcc void %i(%swift.context* swiftasync %arg1, %swift.error* swiftself %arg2)
ret void
}

; Function Attrs: nounwind
define internal swifttailcc void @__swift_suspend_dispatch_4.1(i8* %arg, %swift.context* %arg1, i64 %arg2, i64 %arg3, %T10RR13AC* %arg4) #1 {
entry:
%i = bitcast i8* %arg to void (%swift.context*, i64, i64, %T10RR13AC*)*
musttail call swifttailcc void %i(%swift.context* swiftasync %arg1, i64 %arg2, i64 %arg3, %T10RR13AC* swiftself %arg4)
ret void
}

attributes #0 = { "frame-pointer"="all" }
attributes #1 = { nounwind }
attributes #2 = { argmemonly nofree nosync nounwind willreturn }
attributes #3 = { argmemonly nofree nosync nounwind willreturn writeonly }
attributes #4 = { noinline "frame-pointer"="all" }
attributes #5 = { argmemonly nounwind }
attributes #6 = { nounwind readnone }
attributes #7 = { alwaysinline nounwind "frame-pointer"="all" }
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