[llvm] bed6a6e - [Attributor][NFC] Make the MustBeExecutedContextExplorer optional

[Johannes Doerfert via llvm-commits]

Author: Johannes Doerfert
Date: 2023-06-13T16:49:56-07:00
New Revision: bed6a6e7e06bd3a5a5af15d7a6935d3ba2dc0da4

URL: https://github.com/llvm/llvm-project/commit/bed6a6e7e06bd3a5a5af15d7a6935d3ba2dc0da4
DIFF: https://github.com/llvm/llvm-project/commit/bed6a6e7e06bd3a5a5af15d7a6935d3ba2dc0da4.diff

LOG: [Attributor][NFC] Make the MustBeExecutedContextExplorer optional

For a lightweight pass we do not want to instantiate or use the
MustBeExecutedContextExplorer. This simply allows such a configuration.
While at it, the explorer is now allocated with the bump allocator.

Added: 
    

Modified: 
    llvm/include/llvm/Transforms/IPO/Attributor.h
    llvm/lib/Transforms/IPO/Attributor.cpp
    llvm/lib/Transforms/IPO/AttributorAttributes.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Transforms/IPO/Attributor.h b/llvm/include/llvm/Transforms/IPO/Attributor.h
index 90ed050dde9b7..365301a7e5e9b 100644
--- a/llvm/include/llvm/Transforms/IPO/Attributor.h
+++ b/llvm/include/llvm/Transforms/IPO/Attributor.h
@@ -1164,24 +1164,26 @@ constexpr bool AnalysisGetter::HasLegacyWrapper<
 /// instance down in the abstract attributes.
 struct InformationCache {
   InformationCache(const Module &M, AnalysisGetter &AG,
-                   BumpPtrAllocator &Allocator, SetVector<Function *> *CGSCC)
-      : DL(M.getDataLayout()), Allocator(Allocator),
-        Explorer(
-            /* ExploreInterBlock */ true, /* ExploreCFGForward */ true,
-            /* ExploreCFGBackward */ true,
-            /* LIGetter */
-            [&](const Function &F) { return AG.getAnalysis<LoopAnalysis>(F); },
-            /* DTGetter */
-            [&](const Function &F) {
-              return AG.getAnalysis<DominatorTreeAnalysis>(F);
-            },
-            /* PDTGetter */
-            [&](const Function &F) {
-              return AG.getAnalysis<PostDominatorTreeAnalysis>(F);
-            }),
-        AG(AG), TargetTriple(M.getTargetTriple()) {
+                   BumpPtrAllocator &Allocator, SetVector<Function *> *CGSCC,
+                   bool UseExplorer = true)
+      : DL(M.getDataLayout()), Allocator(Allocator), AG(AG),
+        TargetTriple(M.getTargetTriple()) {
     if (CGSCC)
       initializeModuleSlice(*CGSCC);
+    if (UseExplorer)
+      Explorer = new (Allocator) MustBeExecutedContextExplorer(
+          /* ExploreInterBlock */ true, /* ExploreCFGForward */ true,
+          /* ExploreCFGBackward */ true,
+          /* LIGetter */
+          [&](const Function &F) { return AG.getAnalysis<LoopAnalysis>(F); },
+          /* DTGetter */
+          [&](const Function &F) {
+            return AG.getAnalysis<DominatorTreeAnalysis>(F);
+          },
+          /* PDTGetter */
+          [&](const Function &F) {
+            return AG.getAnalysis<PostDominatorTreeAnalysis>(F);
+          });
   }
 
   ~InformationCache() {
@@ -1193,6 +1195,8 @@ struct InformationCache {
     using AA::InstExclusionSetTy;
     for (auto *BES : BESets)
       BES->~InstExclusionSetTy();
+    if (Explorer)
+      Explorer->~MustBeExecutedContextExplorer();
   }
 
   /// Apply \p CB to all uses of \p F. If \p LookThroughConstantExprUses is
@@ -1275,7 +1279,7 @@ struct InformationCache {
   }
 
   /// Return MustBeExecutedContextExplorer
-  MustBeExecutedContextExplorer &getMustBeExecutedContextExplorer() {
+  MustBeExecutedContextExplorer *getMustBeExecutedContextExplorer() {
     return Explorer;
   }
 
@@ -1381,7 +1385,7 @@ struct InformationCache {
   BumpPtrAllocator &Allocator;
 
   /// MustBeExecutedContextExplorer
-  MustBeExecutedContextExplorer Explorer;
+  MustBeExecutedContextExplorer *Explorer = nullptr;
 
   /// A map with knowledge retained in `llvm.assume` instructions.
   RetainedKnowledgeMap KnowledgeMap;

diff  --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
index df8cb5c3ee902..5e3c2f92730df 100644
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -1204,11 +1204,13 @@ bool IRPosition::getAttrsFromAssumes(Attribute::AttrKind AK,
 
   LLVMContext &Ctx = AssociatedValue.getContext();
   unsigned AttrsSize = Attrs.size();
-  MustBeExecutedContextExplorer &Explorer =
+  MustBeExecutedContextExplorer *Explorer =
       A.getInfoCache().getMustBeExecutedContextExplorer();
-  auto EIt = Explorer.begin(getCtxI()), EEnd = Explorer.end(getCtxI());
+  if (!Explorer)
+    return false;
+  auto EIt = Explorer->begin(getCtxI()), EEnd = Explorer->end(getCtxI());
   for (const auto &It : A2K)
-    if (Explorer.findInContextOf(It.first, EIt, EEnd))
+    if (Explorer->findInContextOf(It.first, EIt, EEnd))
       Attrs.push_back(Attribute::get(Ctx, AK, It.second.Max));
   return AttrsSize != Attrs.size();
 }

diff  --git a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
index 75ddda689dfeb..58297b5fdc9c8 100644
--- a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
+++ b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
@@ -607,10 +607,12 @@ static void followUsesInMBEC(AAType &AA, Attributor &A, StateType &S,
   for (const Use &U : AA.getIRPosition().getAssociatedValue().uses())
     Uses.insert(&U);
 
-  MustBeExecutedContextExplorer &Explorer =
+  MustBeExecutedContextExplorer *Explorer =
       A.getInfoCache().getMustBeExecutedContextExplorer();
+  if (!Explorer)
+    return;
 
-  followUsesInContext<AAType>(AA, A, Explorer, &CtxI, Uses, S);
+  followUsesInContext<AAType>(AA, A, *Explorer, &CtxI, Uses, S);
 
   if (S.isAtFixpoint())
     return;
@@ -655,7 +657,7 @@ static void followUsesInMBEC(AAType &AA, Attributor &A, StateType &S,
   //    }
   // }
 
-  Explorer.checkForAllContext(&CtxI, Pred);
+  Explorer->checkForAllContext(&CtxI, Pred);
   for (const BranchInst *Br : BrInsts) {
     StateType ParentState;
 
@@ -667,7 +669,7 @@ static void followUsesInMBEC(AAType &AA, Attributor &A, StateType &S,
       StateType ChildState;
 
       size_t BeforeSize = Uses.size();
-      followUsesInContext(AA, A, Explorer, &BB->front(), Uses, ChildState);
+      followUsesInContext(AA, A, *Explorer, &BB->front(), Uses, ChildState);
 
       // Erase uses which only appear in the child.
       for (auto It = Uses.begin() + BeforeSize; It != Uses.end();)
@@ -7022,7 +7024,7 @@ ChangeStatus AAHeapToStackFunction::updateImpl(Attributor &A) {
   const auto &LivenessAA =
       A.getAAFor<AAIsDead>(*this, IRPosition::function(*F), DepClassTy::NONE);
 
-  MustBeExecutedContextExplorer &Explorer =
+  MustBeExecutedContextExplorer *Explorer =
       A.getInfoCache().getMustBeExecutedContextExplorer();
 
   bool StackIsAccessibleByOtherThreads =
@@ -7148,7 +7150,7 @@ ChangeStatus AAHeapToStackFunction::updateImpl(Attributor &A) {
       return false;
     }
     Instruction *CtxI = isa<InvokeInst>(AI.CB) ? AI.CB : AI.CB->getNextNode();
-    if (!Explorer.findInContextOf(UniqueFree, CtxI)) {
+    if (!Explorer || !Explorer->findInContextOf(UniqueFree, CtxI)) {
       LLVM_DEBUG(
           dbgs()
           << "[H2S] unique free call might not be executed with the allocation "