[PATCH] D125574: [BasicBlockUtils] Do not move loop metadata if outer loop header.

[Hendrik Greving via Phabricator via llvm-commits]

hgreving updated this revision to Diff 429327.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D125574/new/

https://reviews.llvm.org/D125574

Files:
  llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
  llvm/test/Transforms/LoopSimplify/metadata.ll


Index: llvm/test/Transforms/LoopSimplify/metadata.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/LoopSimplify/metadata.ll
@@ -0,0 +1,34 @@
+; Tests loop-simplify does not move the loop metadata, because
+; the loopexit block is not the latch of the loop _bb6.
+
+; RUN: opt < %s -loop-simplify -S | FileCheck %s
+; CHECK-LABEL: _bb7.loopexit:
+; CHECK-NOT: br label %_bb7, !llvm.loop !0
+; CHECK-LABEL: _bb6:
+; CHECK: br i1 %p, label %_bb6, label %_bb7.loopexit, !llvm.loop !0
+
+define void @func(i1 %p) {
+_bb1:
+  br label %_bb7
+
+_bb7:
+  br i1 %p, label %_bb4, label %_bb2
+
+_bb4:
+  br i1 %p, label %_bb5, label %_bb3
+
+_bb5:
+  br label %_bb3
+
+_bb3:
+  br label %_bb6
+
+_bb6:
+  br i1 %p, label %_bb6, label %_bb7, !llvm.loop !0
+
+_bb2:
+  ret void
+}
+
+!0 = distinct !{!0, !1}
+!1 = !{!"llvm.loop.mustprogress"}
Index: llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
===================================================================
--- llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -1157,7 +1157,7 @@
     UpdatePHINodes(BB, NewBB, Preds, BI, HasLoopExit);
   }
 
-  if (OldLatch) {
+  if (OldLatch && L == LI->getLoopFor(OldLatch)) {
     BasicBlock *NewLatch = L->getLoopLatch();
     if (NewLatch != OldLatch) {
       MDNode *MD = OldLatch->getTerminator()->getMetadata("llvm.loop");


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