[PATCH] D115965: [DSE] Fix a case of invalid dead store elimination

[Marianne Mailhot-Sarrasin 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 rG90d1786ba0c2: [DSE] Fix invalid removal of store instruction (authored by mamai).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D115965/new/

https://reviews.llvm.org/D115965

Files:
  llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
  llvm/test/Transforms/DeadStoreElimination/store-after-loop.ll


Index: llvm/test/Transforms/DeadStoreElimination/store-after-loop.ll
===================================================================
--- llvm/test/Transforms/DeadStoreElimination/store-after-loop.ll
+++ llvm/test/Transforms/DeadStoreElimination/store-after-loop.ll
@@ -7,7 +7,6 @@
 
 ; There is no dead store in this test. Make sure no store is deleted by DSE.
 ; Test case related to bug report PR52774.
-; NOTE: Showing actual (broken) DSE behavior.
 
 define %struct.ilist* @test() {
 ; CHECK-LABEL: @test(
@@ -19,6 +18,8 @@
 ; CHECK-NEXT:    [[LIST_NEW_ILIST_PTR]] = bitcast i8* [[LIST_NEW_I8_PTR]] to %struct.ilist*
 ; CHECK-NEXT:    [[GEP_NEW_VALUE:%.*]] = getelementptr inbounds [[STRUCT_ILIST:%.*]], %struct.ilist* [[LIST_NEW_ILIST_PTR]], i32 0, i32 0
 ; CHECK-NEXT:    store i32 42, i32* [[GEP_NEW_VALUE]], align 8
+; CHECK-NEXT:    [[GEP_NEW_NEXT:%.*]] = getelementptr inbounds [[STRUCT_ILIST]], %struct.ilist* [[LIST_NEW_ILIST_PTR]], i32 0, i32 1
+; CHECK-NEXT:    store %struct.ilist* [[LIST_NEXT]], %struct.ilist** [[GEP_NEW_NEXT]], align 4
 ; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
 ; CHECK-NEXT:    [[COND:%.*]] = icmp eq i32 [[IV_NEXT]], 10
 ; CHECK-NEXT:    br i1 [[COND]], label [[EXIT:%.*]], label [[LOOP]]
Index: llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
+++ llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -1209,17 +1209,10 @@
   /// loop. In particular, this guarantees that it only references a single
   /// MemoryLocation during execution of the containing function.
   bool isGuaranteedLoopInvariant(const Value *Ptr) {
-    auto IsGuaranteedLoopInvariantBase = [this](const Value *Ptr) {
+    auto IsGuaranteedLoopInvariantBase = [](const Value *Ptr) {
       Ptr = Ptr->stripPointerCasts();
-      if (auto *I = dyn_cast<Instruction>(Ptr)) {
-        if (isa<AllocaInst>(Ptr))
-          return true;
-
-        if (isAllocLikeFn(I, &TLI))
-          return true;
-
-        return false;
-      }
+      if (auto *I = dyn_cast<Instruction>(Ptr))
+        return I->getParent()->isEntryBlock();
       return true;
     };
 


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