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Fix coro lowering of single predecessor phis
Code assumes that uses of single predecessor phis are not live accross suspend points. Cleanup any single predecessor phis preceeding the code making this assumption. rdar://76020301 Differential Revision: https://reviews.llvm.org/D105488
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‎llvm/lib/Transforms/Coroutines/CoroFrame.cpp

Lines changed: 22 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1839,6 +1839,24 @@ static void rewritePHIsForCleanupPad(BasicBlock *CleanupPadBB,
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}
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}
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static void cleanupSinglePredPHIs(Function &F) {
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SmallVector<PHINode *, 32> Worklist;
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for (auto &BB : F) {
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for (auto &Phi : BB.phis()) {
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if (Phi.getNumIncomingValues() == 1) {
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Worklist.push_back(&Phi);
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} else
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break;
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}
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}
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while (!Worklist.empty()) {
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auto *Phi = Worklist.back();
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Worklist.pop_back();
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auto *OriginalValue = Phi->getIncomingValue(0);
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Phi->replaceAllUsesWith(OriginalValue);
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}
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}
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static void rewritePHIs(BasicBlock &BB) {
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// For every incoming edge we will create a block holding all
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// incoming values in a single PHI nodes.
@@ -2602,6 +2620,10 @@ void coro::buildCoroutineFrame(Function &F, Shape &Shape) {
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}
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}
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// Later code makes structural assumptions about single predecessors phis e.g
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// that they are not live accross a suspend point.
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cleanupSinglePredPHIs(F);
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// Transforms multi-edge PHI Nodes, so that any value feeding into a PHI will
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// never has its definition separated from the PHI by the suspend point.
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rewritePHIs(F);

‎llvm/test/Transforms/Coroutines/coro-async-phi.ll

Lines changed: 196 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,196 @@
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; RUN: opt < %s -enable-coroutines -O0 -S | FileCheck --check-prefixes=CHECK %s
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; RUN: opt < %s -enable-coroutines -passes='default<O0>' -S | FileCheck --check-prefixes=CHECK %s
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%swift.async_func_pointer = type <{ i32, i32 }>
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%swift.context = type { %swift.context*, void (%swift.context*)*, i64 }
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%T10RR13AC = type <{ %swift.refcounted, %swift.defaultactor }>
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%swift.refcounted = type { %swift.type*, i64 }
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%swift.type = type { i64 }
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%swift.defaultactor = type { [10 x i8*] }
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%swift.bridge = type opaque
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%swift.error = type opaque
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%swift.executor = type {}
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@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
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declare void @use(i8*)
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; This used to crash.
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; CHECK: repo
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define hidden swifttailcc void @repo(%swift.context* swiftasync %arg, i64 %arg1, i64 %arg2, %T10RR13AC* swiftself %arg3) #0 {
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entry:
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%i = alloca %swift.context*, align 8
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%i11 = call token @llvm.coro.id.async(i32 20, i32 16, i32 0, i8* bitcast (%swift.async_func_pointer* @repoTU to i8*))
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%i12 = call i8* @llvm.coro.begin(token %i11, i8* null)
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%i18 = call i8* @llvm.coro.async.resume()
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call void @use(i8* %i18)
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%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)
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%i22 = extractvalue { i8* } %i21, 0
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%i23 = call i8* @__swift_async_resume_get_context(i8* %i22)
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%i28 = icmp eq i64 %arg2, 0
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br i1 %i28, label %bb126, label %bb
32+
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bb: ; preds = %entry
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%i29 = inttoptr i64 %arg2 to %swift.bridge*
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br label %bb30
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bb30: ; preds = %bb
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%i31 = phi i64 [ %arg1, %bb ]
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%i32 = phi %swift.bridge* [ %i29, %bb ]
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%i35 = ptrtoint %swift.bridge* %i32 to i64
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%i36 = bitcast %T10RR13AC* %arg3 to %swift.type**
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%i37 = load %swift.type*, %swift.type** %i36, align 8
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%i38 = bitcast %swift.type* %i37 to void (%swift.context*, i64, i64, %T10RR13AC*)**
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%i39 = getelementptr inbounds void (%swift.context*, i64, i64, %T10RR13AC*)*, void (%swift.context*, i64, i64, %T10RR13AC*)** %i38, i64 11
45+
%i40 = load void (%swift.context*, i64, i64, %T10RR13AC*)*, void (%swift.context*, i64, i64, %T10RR13AC*)** %i39, align 8
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%i41 = bitcast void (%swift.context*, i64, i64, %T10RR13AC*)* %i40 to %swift.async_func_pointer*
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%i42 = getelementptr inbounds %swift.async_func_pointer, %swift.async_func_pointer* %i41, i32 0, i32 0
48+
%i43 = load i32, i32* %i42, align 8
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%i44 = sext i32 %i43 to i64
50+
%i45 = ptrtoint i32* %i42 to i64
51+
%i46 = add i64 %i45, %i44
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%i47 = inttoptr i64 %i46 to i8*
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%i48 = bitcast i8* %i47 to void (%swift.context*, i64, i64, %T10RR13AC*)*
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%i52 = call swiftcc i8* @swift_task_alloc(i64 24) #1
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%i53 = bitcast i8* %i52 to <{ %swift.context*, void (%swift.context*)*, i32 }>*
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%i54 = load %swift.context*, %swift.context** %i, align 8
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%i55 = getelementptr inbounds <{ %swift.context*, void (%swift.context*)*, i32 }>, <{ %swift.context*, void (%swift.context*)*, i32 }>* %i53, i32 0, i32 0
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store %swift.context* %i54, %swift.context** %i55, align 8
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%i56 = call i8* @llvm.coro.async.resume()
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call void @use(i8* %i56)
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%i57 = bitcast i8* %i56 to void (%swift.context*)*
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%i58 = getelementptr inbounds <{ %swift.context*, void (%swift.context*)*, i32 }>, <{ %swift.context*, void (%swift.context*)*, i32 }>* %i53, i32 0, i32 1
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store void (%swift.context*)* %i57, void (%swift.context*)** %i58, align 8
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%i59 = bitcast i8* %i52 to %swift.context*
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%i60 = bitcast void (%swift.context*, i64, i64, %T10RR13AC*)* %i48 to i8*
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%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)
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%i62 = extractvalue { i8*, %swift.error* } %i61, 0
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%i63 = call i8* @__swift_async_resume_project_context(i8* %i62)
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%i64 = bitcast i8* %i63 to %swift.context*
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store %swift.context* %i64, %swift.context** %i, align 8
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%i65 = extractvalue { i8*, %swift.error* } %i61, 1
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call swiftcc void @swift_task_dealloc(i8* %i52) #1
73+
br i1 %i28, label %bb126, label %bb68
74+
75+
bb68: ; preds = %bb30
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%i69 = call i8* @llvm.coro.async.resume()
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call void @use(i8* %i69)
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%i70 = load %swift.context*, %swift.context** %i, align 8
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%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)
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%i77 = ptrtoint %swift.bridge* %i32 to i64
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%i78 = bitcast %T10RR13AC* %arg3 to %swift.type**
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%i79 = load %swift.type*, %swift.type** %i78, align 8
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%i80 = bitcast %swift.type* %i79 to void (%swift.context*, i64, i64, %T10RR13AC*)**
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%i81 = getelementptr inbounds void (%swift.context*, i64, i64, %T10RR13AC*)*, void (%swift.context*, i64, i64, %T10RR13AC*)** %i80, i64 11
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%i82 = load void (%swift.context*, i64, i64, %T10RR13AC*)*, void (%swift.context*, i64, i64, %T10RR13AC*)** %i81, align 8
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%i83 = bitcast void (%swift.context*, i64, i64, %T10RR13AC*)* %i82 to %swift.async_func_pointer*
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%i84 = getelementptr inbounds %swift.async_func_pointer, %swift.async_func_pointer* %i83, i32 0, i32 0
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%i85 = load i32, i32* %i84, align 8
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%i86 = sext i32 %i85 to i64
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%i87 = ptrtoint i32* %i84 to i64
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%i88 = add i64 %i87, %i86
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%i89 = inttoptr i64 %i88 to i8*
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%i90 = bitcast i8* %i89 to void (%swift.context*, i64, i64, %T10RR13AC*)*
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%i94 = call swiftcc i8* @swift_task_alloc(i64 24) #1
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%i98 = call i8* @llvm.coro.async.resume()
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call void @use(i8* %i98)
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%i102 = bitcast void (%swift.context*, i64, i64, %T10RR13AC*)* %i90 to i8*
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%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)
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call swiftcc void @swift_task_dealloc(i8* %i94) #1
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br label %bb126
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bb126:
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%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)
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unreachable
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}
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; Function Attrs: nounwind
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declare token @llvm.coro.id.async(i32, i32, i32, i8*) #1
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; Function Attrs: nounwind
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declare i8* @llvm.coro.begin(token, i8* writeonly) #1
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; Function Attrs: argmemonly nofree nosync nounwind willreturn writeonly
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declare void @llvm.memset.p0i8.i64(i8* nocapture writeonly, i8, i64, i1 immarg) #3
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; Function Attrs: nounwind
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declare i8* @llvm.coro.async.resume() #1
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; Function Attrs: noinline
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define linkonce_odr hidden i8* @__swift_async_resume_get_context(i8* %arg) #4 {
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entry:
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ret i8* %arg
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}
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; Function Attrs: nounwind
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declare extern_weak swifttailcc void @swift_task_switch(%swift.context*, i8*, %swift.executor*) #1
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; Function Attrs: nounwind
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define internal swifttailcc void @__swift_suspend_point(i8* %arg, %swift.executor* %arg1, %swift.context* %arg2) #1 {
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entry:
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musttail call swifttailcc void @swift_task_switch(%swift.context* swiftasync %arg2, i8* %arg, %swift.executor* %arg1) #1
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ret void
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}
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; Function Attrs: nounwind
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declare { i8* } @llvm.coro.suspend.async.sl_p0i8s(i32, i8*, i8*, ...) #1
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; Function Attrs: nounwind
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declare i1 @llvm.coro.end.async(i8*, i1, ...) #1
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; Function Attrs: argmemonly nounwind
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declare extern_weak swiftcc i8* @swift_task_alloc(i64) #5
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; Function Attrs: nounwind readnone
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declare i8** @llvm.swift.async.context.addr() #6
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; Function Attrs: alwaysinline nounwind
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define linkonce_odr hidden i8* @__swift_async_resume_project_context(i8* %arg) #7 {
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entry:
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%i = bitcast i8* %arg to i8**
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%i1 = load i8*, i8** %i, align 8
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%i2 = call i8** @llvm.swift.async.context.addr()
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store i8* %i1, i8** %i2, align 8
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ret i8* %i1
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}
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; Function Attrs: nounwind
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declare { i8*, %swift.error* } @llvm.coro.suspend.async.sl_p0i8p0s_swift.errorss(i32, i8*, i8*, ...) #1
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; Function Attrs: argmemonly nounwind
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declare extern_weak swiftcc void @swift_task_dealloc(i8*) #5
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; Function Attrs: nounwind
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define internal swifttailcc void @__swift_suspend_dispatch_4(i8* %arg, %swift.context* %arg1, i64 %arg2, i64 %arg3, %T10RR13AC* %arg4) #1 {
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entry:
166+
%i = bitcast i8* %arg to void (%swift.context*, i64, i64, %T10RR13AC*)*
167+
musttail call swifttailcc void %i(%swift.context* swiftasync %arg1, i64 %arg2, i64 %arg3, %T10RR13AC* swiftself %arg4)
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ret void
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}
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declare swifttailcc void @doIt(%swift.context* swiftasync %arg1, %swift.error* swiftself %arg2)
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173+
; Function Attrs: nounwind
174+
define internal swifttailcc void @__swift_suspend_dispatch_2(i8* %arg, %swift.context* %arg1, %swift.error* %arg2) #1 {
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entry:
176+
%i = bitcast i8* %arg to void (%swift.context*, %swift.error*)*
177+
musttail call swifttailcc void %i(%swift.context* swiftasync %arg1, %swift.error* swiftself %arg2)
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ret void
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}
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; Function Attrs: nounwind
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define internal swifttailcc void @__swift_suspend_dispatch_4.1(i8* %arg, %swift.context* %arg1, i64 %arg2, i64 %arg3, %T10RR13AC* %arg4) #1 {
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entry:
184+
%i = bitcast i8* %arg to void (%swift.context*, i64, i64, %T10RR13AC*)*
185+
musttail call swifttailcc void %i(%swift.context* swiftasync %arg1, i64 %arg2, i64 %arg3, %T10RR13AC* swiftself %arg4)
186+
ret void
187+
}
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attributes #0 = { "frame-pointer"="all" }
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attributes #1 = { nounwind }
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attributes #2 = { argmemonly nofree nosync nounwind willreturn }
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attributes #3 = { argmemonly nofree nosync nounwind willreturn writeonly }
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attributes #4 = { noinline "frame-pointer"="all" }
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attributes #5 = { argmemonly nounwind }
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attributes #6 = { nounwind readnone }
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attributes #7 = { alwaysinline nounwind "frame-pointer"="all" }

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