[CSI] Fix splitting of predecessors of detach-continutaion blocks to …

…maintain Tapir-CFG structure.
OpenCilk · Feb 26, 2021 · 4ea2836 · 4ea2836
1 parent 999bd50
commit 4ea2836
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diff --git a/llvm/lib/Transforms/Instrumentation/CilkSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/CilkSanitizer.cpp
@@ -1060,6 +1060,7 @@ static void setupBlock(BasicBlock *BB, DominatorTree *DT, LoopInfo *LI,
   // Partition the predecessors of the landing pad.
   for (BasicBlock *Pred : predecessors(BB)) {
     if (isa<DetachInst>(Pred->getTerminator()) ||
+        isa<ReattachInst>(Pred->getTerminator()) ||
         isDetachedRethrow(Pred->getTerminator()))
       DetachPreds.push_back(Pred);
     else if (isTaskFrameResume(Pred->getTerminator()))

diff --git a/llvm/lib/Transforms/Instrumentation/ComprehensiveStaticInstrumentation.cpp b/llvm/lib/Transforms/Instrumentation/ComprehensiveStaticInstrumentation.cpp
@@ -773,6 +773,7 @@ static void setupBlock(BasicBlock *BB, const TargetLibraryInfo *TLI,
   // Partition the predecessors of the landing pad.
   for (BasicBlock *Pred : predecessors(BB)) {
     if (isa<DetachInst>(Pred->getTerminator()) ||
+        isa<ReattachInst>(Pred->getTerminator()) ||
         isDetachedRethrow(Pred->getTerminator()))
       DetachPreds.push_back(Pred);
     else if (isTaskFrameResume(Pred->getTerminator()))

diff --git a/llvm/test/Transforms/Tapir/csi-detach-continue-split.ll b/llvm/test/Transforms/Tapir/csi-detach-continue-split.ll
@@ -0,0 +1,67 @@
+; Check that the CSI pass properly splits the predecessors of a detach-continuation block.
+;
+; RUN: opt < %s -csi -S -o - | FileCheck %s
+; RUN: opt < %s -passes='csi' -S -o - | FileCheck %s
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; Function Attrs: argmemonly nounwind willreturn
+declare token @llvm.syncregion.start() #0
+
+define dso_local void @QuadNode_addIntersections() local_unnamed_addr #1 {
+entry:
+  %syncreg.i28 = tail call token @llvm.syncregion.start()
+  br i1 undef, label %if.then.tf, label %if.else
+
+if.then.tf:                                       ; preds = %entry
+  detach within %syncreg.i28, label %det.achd, label %det.cont.tf
+
+det.achd:                                         ; preds = %if.then.tf
+  unreachable
+
+det.cont.tf:                                      ; preds = %if.then.tf
+  detach within %syncreg.i28, label %det.achd1.tf.tf.tf, label %if.end
+
+; CHECK: det.cont.tf:
+; CHECK: detach within %syncreg.i28, label %[[DETACHED:.+]], label %[[CONTINUE:.+]]
+
+; CHECK: [[CONTINUE]]:
+; CHECK-NEXT: call void @__csi_detach_continue(
+; CHECK-NEXT: br label %if.end
+
+det.achd1.tf.tf.tf:                               ; preds = %det.cont.tf
+  br label %det.achd1.tf.tf.tf.tf
+
+det.achd1.tf.tf.tf.tf:                            ; preds = %det.achd1.tf.tf.tf
+  %tf.i = tail call token @llvm.taskframe.create()
+  %syncreg.i = tail call token @llvm.syncregion.start() #2
+  reattach within %syncreg.i28, label %if.end
+
+; CHECK: [[DETACHED]]:
+; CHECK: reattach within %syncreg.i28, label %[[CONTINUE]]
+
+if.else:                                          ; preds = %entry
+  sync within %syncreg.i28, label %if.end
+
+; CHECK: if.else:
+; CHECK: sync within %syncreg.i28, label %[[SYNC_SPLIT:.+]]
+
+; CHECK: [[SYNC_SPLIT]]:
+; CHECK: call void @__csi_after_sync(
+; CHECK: br label %if.end
+
+if.end:                                           ; preds = %if.else, %det.achd1.tf.tf.tf.tf, %det.cont.tf
+  unreachable
+}
+
+; Function Attrs: argmemonly nounwind willreturn
+declare token @llvm.taskframe.create() #0
+
+attributes #0 = { argmemonly nounwind willreturn }
+attributes #1 = { "use-soft-float"="false" }
+attributes #2 = { nounwind }
+
+!llvm.ident = !{!0}
+
+!0 = !{!"clang version 10.0.1 ([email protected]:OpenCilk/opencilk-project.git 94a2a3eb6c9f8dd53def6e21c5ab8ff45acb586f)"}