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CoroSplit: Replace ad-hoc implementation of reachability with API from CFG.h #2994

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Merged
merged 1 commit into from
May 24, 2021
Merged

CoroSplit: Replace ad-hoc implementation of reachability with API from CFG.h #2994

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6 changes: 5 additions & 1 deletion llvm/lib/Transforms/Coroutines/CoroSplit.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,7 @@
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Analysis/CFG.h"
#include "llvm/Analysis/CallGraph.h"
#include "llvm/Analysis/CallGraphSCCPass.h"
#include "llvm/Analysis/LazyCallGraph.h"
Expand All @@ -37,6 +38,7 @@
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/GlobalVariable.h"
Expand Down Expand Up @@ -659,8 +661,10 @@ static void salvageCoroDebugInfo(llvm::Function &NewF) {

// Remove all salvaged dbg.declare intrinsics that became
// either unreachable or stale due to the CoroSplit transformation.
DominatorTree DomTree(NewF);
SmallDenseMap<BasicBlock *, bool, 8> UnreachableCache;
auto IsUnreachableBlock = [&](BasicBlock *BB) {
return BB->hasNPredecessors(0) && BB != &NewF.getEntryBlock();
return !isPotentiallyReachable(&NewF.getEntryBlock(), BB, &DomTree);
};
for (DbgDeclareInst *DDI : Worklist) {
if (IsUnreachableBlock(DDI->getParent()))
Expand Down
4 changes: 4 additions & 0 deletions llvm/test/Transforms/Coroutines/coro-debug.ll
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Expand Up @@ -20,6 +20,7 @@ entry:
store i8* %2, i8** %coro_hdl, align 8, !dbg !16
%3 = call i8 @llvm.coro.suspend(token none, i1 false), !dbg !17
%conv = sext i8 %3 to i32, !dbg !17
%late_local = alloca i32, align 4
call void @coro.devirt.trigger(i8* null)
switch i32 %conv, label %sw.default [
i32 0, label %sw.bb
Expand Down Expand Up @@ -57,6 +58,7 @@ coro_Cleanup: ; preds = %sw.epilog, %sw.bb1
coro_Suspend: ; preds = %coro_Cleanup, %sw.default
%7 = call i1 @llvm.coro.end(i8* null, i1 false) #7, !dbg !24
%8 = load i8*, i8** %coro_hdl, align 8, !dbg !24
store i32 0, i32* %late_local, !dbg !24
ret i8* %8, !dbg !24
}

Expand Down Expand Up @@ -147,6 +149,8 @@ attributes #7 = { noduplicate }
; CHECK: store %f.Frame* {{.*}}, %f.Frame** %[[DBG_PTR]]
; CHECK-NOT: alloca %struct.test*
; CHECK: call void @llvm.dbg.declare(metadata i32 0, metadata ![[RESUME_CONST:[0-9]+]], metadata !DIExpression())
; Note that keeping the undef value here could be acceptable, too.
; CHECK-NOT: call void @llvm.dbg.declare(metadata i32* undef, metadata !{{[0-9]+}}, metadata !DIExpression())
; CHECK: call void @coro.devirt.trigger(i8* null)
; CHECK: define internal fastcc void @f.destroy(%f.Frame* noalias nonnull align 8 dereferenceable(32) %FramePtr) #0 !dbg ![[DESTROY:[0-9]+]]
; CHECK: define internal fastcc void @f.cleanup(%f.Frame* noalias nonnull align 8 dereferenceable(32) %FramePtr) #0 !dbg ![[CLEANUP:[0-9]+]]
Expand Down