[PATCH] D109197: [LoopPredication] Fix MemorySSA crash in predicateLoopExits

[Anna Thomas via Phabricator via llvm-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGf661ce209f19: [LoopPredication] Fix MemorySSA crash in predicateLoopExits (authored by anna).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D109197/new/

https://reviews.llvm.org/D109197

Files:
  llvm/lib/Transforms/Scalar/LoopPredication.cpp
  llvm/test/Transforms/LoopPredication/predicate-exits.ll


Index: llvm/test/Transforms/LoopPredication/predicate-exits.ll
===================================================================
--- llvm/test/Transforms/LoopPredication/predicate-exits.ll
+++ llvm/test/Transforms/LoopPredication/predicate-exits.ll
@@ -1082,6 +1082,34 @@
   ret i32 %result
 }
 
+define void @test_memssa() {
+bb:
+  %tmp = call i1 @llvm.experimental.widenable.condition()
+  %tmp1 = call i1 @llvm.experimental.widenable.condition()
+  br i1 %tmp, label %bb3, label %bb2
+
+bb2:                                              ; preds = %bb
+  unreachable
+
+bb3:                                              ; preds = %bb
+  br label %bb4
+
+bb4:                                              ; preds = %bb6, %bb3
+  %tmp5 = phi i32 [ %tmp7, %bb6 ], [ 0, %bb3 ]
+  br i1 undef, label %bb10, label %bb6
+
+bb6:                                              ; preds = %bb4
+  %tmp7 = add nuw nsw i32 %tmp5, 1
+  %tmp8 = icmp ult i32 %tmp7, undef
+  br i1 %tmp8, label %bb4, label %bb9
+
+bb9:                                              ; preds = %bb6
+  ret void
+
+bb10:                                             ; preds = %bb4
+  ret void
+}
+
 
 
 declare void @unknown()
Index: llvm/lib/Transforms/Scalar/LoopPredication.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/LoopPredication.cpp
+++ llvm/lib/Transforms/Scalar/LoopPredication.cpp
@@ -1127,6 +1127,10 @@
   // modifying the operand is legal.
   auto *IP = cast<Instruction>(WidenableBR->getCondition());
   IP->moveBefore(WidenableBR);
+  if (MSSAU)
+    if (auto *MUD = MSSAU->getMemorySSA()->getMemoryAccess(IP))
+       MSSAU->moveToPlace(MUD, WidenableBR->getParent(),
+                          MemorySSA::BeforeTerminator);
   Rewriter.setInsertPoint(IP);
   IRBuilder<> B(IP);
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D109197.370462.patch
Type: text/x-patch
Size: 1821 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20210903/9690fe75/attachment.bin>