date:20220106

[llvm-branch-commits] [llvm] 426297c - [DSE] Add test case showing bug PR52774.

2022-01-06 Thread Tom Stellard via llvm-branch-commits


Author: Marianne Mailhot-Sarrasin
Date: 2022-01-06T21:41:01-08:00
New Revision: 426297cce9d5138e6085d51c66a8a1dc4dd23b17

URL: 
https://github.com/llvm/llvm-project/commit/426297cce9d5138e6085d51c66a8a1dc4dd23b17
DIFF: 
https://github.com/llvm/llvm-project/commit/426297cce9d5138e6085d51c66a8a1dc4dd23b17.diff

LOG: [DSE] Add test case showing bug PR52774.

Pre-commiting the test case before the bug fix.

Reviewed by: Florian Hahn

Differential revision: https://reviews.llvm.org/D115965

(cherry picked from commit df590567aa435211dea1f306b55b8d4ba92ddbb1)

Added: 
llvm/test/Transforms/DeadStoreElimination/store-after-loop.ll

Modified: 


Removed: 




diff  --git a/llvm/test/Transforms/DeadStoreElimination/store-after-loop.ll 
b/llvm/test/Transforms/DeadStoreElimination/store-after-loop.ll
new file mode 100644
index 0..27c7c139acb16
--- /dev/null
+++ b/llvm/test/Transforms/DeadStoreElimination/store-after-loop.ll
@@ -0,0 +1,60 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=dse -S | FileCheck %s
+
+target datalayout = "E-m:e-p:32:32-i64:32-f64:32:64-a:0:32-n32-S32"
+
+%struct.ilist = type { i32, %struct.ilist* }
+
+; 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(
+; CHECK-NEXT:br label [[LOOP:%.*]]
+; CHECK:   loop:
+; CHECK-NEXT:[[IV:%.*]] = phi i32 [ 0, [[TMP0:%.*]] ], [ [[IV_NEXT:%.*]], 
[[LOOP]] ]
+; CHECK-NEXT:[[LIST_NEXT:%.*]] = phi %struct.ilist* [ null, [[TMP0]] ], [ 
[[LIST_NEW_ILIST_PTR:%.*]], [[LOOP]] ]
+; CHECK-NEXT:[[LIST_NEW_I8_PTR:%.*]] = tail call align 8 
dereferenceable_or_null(8) i8* @malloc(i32 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:[[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]]
+; CHECK:   exit:
+; CHECK-NEXT:[[LIST_LAST_ILIST_PTR:%.*]] = bitcast i8* [[LIST_NEW_I8_PTR]] 
to %struct.ilist*
+; CHECK-NEXT:[[GEP_LIST_LAST_NEXT:%.*]] = getelementptr inbounds 
[[STRUCT_ILIST]], %struct.ilist* [[LIST_LAST_ILIST_PTR]], i32 0, i32 1
+; CHECK-NEXT:store %struct.ilist* null, %struct.ilist** 
[[GEP_LIST_LAST_NEXT]], align 4
+; CHECK-NEXT:[[GEP_LIST_NEXT_NEXT:%.*]] = getelementptr inbounds 
[[STRUCT_ILIST]], %struct.ilist* [[LIST_NEXT]], i32 0, i32 1
+; CHECK-NEXT:[[LOADED_PTR:%.*]] = load %struct.ilist*, %struct.ilist** 
[[GEP_LIST_NEXT_NEXT]], align 4
+; CHECK-NEXT:ret %struct.ilist* [[LOADED_PTR]]
+;
+  br label %loop
+
+loop:
+  %iv = phi i32 [ 0, %0 ], [ %iv.next, %loop ]
+  %list.next = phi %struct.ilist* [ null, %0 ], [ %list.new.ilist.ptr, %loop ]
+  %list.new.i8.ptr = tail call align 8 dereferenceable_or_null(8) i8* 
@malloc(i32 8)
+  %list.new.ilist.ptr = bitcast i8* %list.new.i8.ptr to %struct.ilist*
+  %gep.new.value = getelementptr inbounds %struct.ilist, %struct.ilist* 
%list.new.ilist.ptr, i32 0, i32 0
+  store i32 42, i32* %gep.new.value, align 8
+  %gep.new.next = getelementptr inbounds %struct.ilist, %struct.ilist* 
%list.new.ilist.ptr, i32 0, i32 1
+  store %struct.ilist* %list.next, %struct.ilist** %gep.new.next, align 4
+  %iv.next = add nuw nsw i32 %iv, 1
+  %cond = icmp eq i32 %iv.next, 10
+  br i1 %cond, label %exit, label %loop
+
+exit:
+  %list.last.ilist.ptr = bitcast i8* %list.new.i8.ptr to %struct.ilist*
+  %gep.list.last.next = getelementptr inbounds %struct.ilist, %struct.ilist* 
%list.last.ilist.ptr, i32 0, i32 1
+  store %struct.ilist* null, %struct.ilist** %gep.list.last.next, align 4
+  %gep.list.next.next = getelementptr inbounds %struct.ilist, %struct.ilist* 
%list.next, i32 0, i32 1
+  %loaded_ptr = load %struct.ilist*, %struct.ilist** %gep.list.next.next, 
align 4
+  ret %struct.ilist* %loaded_ptr  ; use 
loaded pointer
+}
+
+; Function Attrs: inaccessiblememonly nounwind
+declare noalias noundef align 8 i8* @malloc(i32 noundef) local_unnamed_addr #0
+
+attributes #0 = { inaccessiblememonly nounwind}



___
llvm-branch-commits mailing list
[email protected]
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits

[llvm-branch-commits] [llvm] 33f7aa6 - [DSE] Fix invalid removal of store instruction

2022-01-06 Thread Tom Stellard via llvm-branch-commits


Author: Marianne Mailhot-Sarrasin
Date: 2022-01-06T21:41:09-08:00
New Revision: 33f7aa65f5d77bdec6a528af65ff0fa9033370c2

URL: 
https://github.com/llvm/llvm-project/commit/33f7aa65f5d77bdec6a528af65ff0fa9033370c2
DIFF: 
https://github.com/llvm/llvm-project/commit/33f7aa65f5d77bdec6a528af65ff0fa9033370c2.diff

LOG: [DSE] Fix invalid removal of store instruction

Fix handling of alloc-like instructions in isGuaranteedLoopInvariant(). It was 
not valid when the 'KillingDef' was outside of the loop, while the 'CurrentDef' 
was inside the loop. In that case, the 'KillingDef' only overwrites the 
definition from the last iteration of the loop, and not the ones of all 
iterations. Therefor it does not make the 'CurrentDef' to be dead, and must not 
remove it.

Fixing issue : https://github.com/llvm/llvm-project/issues/52774

Reviewed by: Florian Hahn

Differential revision: https://reviews.llvm.org/D115965

(cherry picked from commit 90d1786ba0c233456b7785fe4b93eca835d56028)

Added: 


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

Removed: 




diff  --git a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp 
b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
index d22b3f409585c..9d8130d1ac025 100644
--- a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -1303,17 +1303,10 @@ struct DSEState {
   /// 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(Ptr)) {
-if (isa(Ptr))
-  return true;
-
-if (isAllocLikeFn(I, &TLI))
-  return true;
-
-return false;
-  }
+  if (auto *I = dyn_cast(Ptr))
+return I->getParent()->isEntryBlock();
   return true;
 };
 

diff  --git a/llvm/test/Transforms/DeadStoreElimination/store-after-loop.ll 
b/llvm/test/Transforms/DeadStoreElimination/store-after-loop.ll
index 27c7c139acb16..1e98fd7404a37 100644
--- a/llvm/test/Transforms/DeadStoreElimination/store-after-loop.ll
+++ b/llvm/test/Transforms/DeadStoreElimination/store-after-loop.ll
@@ -7,7 +7,6 @@ target datalayout = 
"E-m:e-p:32:32-i64:32-f64:32:64-a:0:32-n32-S32"
 
 ; 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 @@ define %struct.ilist* @test() {
 ; 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]]



___
llvm-branch-commits mailing list
[email protected]
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits

[llvm-branch-commits] [llvm] 426297c - [DSE] Add test case showing bug PR52774.

[llvm-branch-commits] [llvm] 33f7aa6 - [DSE] Fix invalid removal of store instruction

2 matches

Site Navigation

Mail list logo

Footer information