From: Johannes Doerfert <jdoerfert@anl.gov>
Date: Tue, 17 Sep 2019 10:52:41 +0000 (+0000)
Subject: [Attributor][Fix] Initialize the cache prior to using it
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=80781fec87ffe1ca6f4eaa66c5e1cf3300ff96ee;p=llvm

[Attributor][Fix] Initialize the cache prior to using it

Summary:
There were segfaults as we modified and iterated the instruction maps in
the cache at the same time. This was happening because we created new
instructions while we populated the cache. This fix changes the order
in which we perform these actions. First, the caches for the whole
module are created, then we start to create abstract attributes.

I don't have a unit test but the LLVM test suite exposes this problem.

Reviewers: uenoku, sstefan1

Subscribers: hiraditya, bollu, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67232

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@372105 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/Transforms/IPO/Attributor.h b/include/llvm/Transforms/IPO/Attributor.h
index 95cc07d31b3..3be021bc336 100644
--- a/include/llvm/Transforms/IPO/Attributor.h
+++ b/include/llvm/Transforms/IPO/Attributor.h
@@ -733,6 +733,12 @@ struct Attributor {
   /// various places.
   void identifyDefaultAbstractAttributes(Function &F);
 
+  /// Initialize the information cache for queries regarding function \p F.
+  ///
+  /// This method needs to be called for all function that might be looked at
+  /// through the information cache interface *prior* to looking at them.
+  void initializeInformationCache(Function &F);
+
   /// Mark the internal function \p F as live.
   ///
   /// This will trigger the identification and initialization of attributes for
diff --git a/lib/Transforms/IPO/Attributor.cpp b/lib/Transforms/IPO/Attributor.cpp
index a6f8472e85d..654f2084be4 100644
--- a/lib/Transforms/IPO/Attributor.cpp
+++ b/lib/Transforms/IPO/Attributor.cpp
@@ -1863,12 +1863,14 @@ struct AAIsDeadImpl : public AAIsDead {
 
   void exploreFromEntry(Attributor &A, const Function *F) {
     ToBeExploredPaths.insert(&(F->getEntryBlock().front()));
-    assumeLive(A, F->getEntryBlock());
 
     for (size_t i = 0; i < ToBeExploredPaths.size(); ++i)
       if (const Instruction *NextNoReturnI =
               findNextNoReturn(A, ToBeExploredPaths[i]))
         NoReturnCalls.insert(NextNoReturnI);
+
+    // Mark the block live after we looked for no-return instructions.
+    assumeLive(A, F->getEntryBlock());
   }
 
   /// Find the next assumed noreturn instruction in the block of \p I starting
@@ -3537,6 +3539,26 @@ bool Attributor::checkForAllReturnedValues(
       });
 }
 
+static bool
+checkForAllInstructionsImpl(InformationCache::OpcodeInstMapTy &OpcodeInstMap,
+                            const function_ref<bool(Instruction &)> &Pred,
+                            const AAIsDead *LivenessAA, bool &AnyDead,
+                            const ArrayRef<unsigned> &Opcodes) {
+  for (unsigned Opcode : Opcodes) {
+    for (Instruction *I : OpcodeInstMap[Opcode]) {
+      // Skip dead instructions.
+      if (LivenessAA && LivenessAA->isAssumedDead(I)) {
+        AnyDead = true;
+        continue;
+      }
+
+      if (!Pred(*I))
+        return false;
+    }
+  }
+  return true;
+}
+
 bool Attributor::checkForAllInstructions(
     const llvm::function_ref<bool(Instruction &)> &Pred,
     const AbstractAttribute &QueryingAA, const ArrayRef<unsigned> &Opcodes) {
@@ -3555,18 +3577,8 @@ bool Attributor::checkForAllInstructions(
 
   auto &OpcodeInstMap =
       InfoCache.getOpcodeInstMapForFunction(*AssociatedFunction);
-  for (unsigned Opcode : Opcodes) {
-    for (Instruction *I : OpcodeInstMap[Opcode]) {
-      // Skip dead instructions.
-      if (LivenessAA.isAssumedDead(I)) {
-        AnyDead = true;
-        continue;
-      }
-
-      if (!Pred(*I))
-        return false;
-    }
-  }
+  if (!checkForAllInstructionsImpl(OpcodeInstMap, Pred, &LivenessAA, AnyDead, Opcodes))
+    return false;
 
   // If we actually used liveness information so we have to record a dependence.
   if (AnyDead)
@@ -3852,6 +3864,48 @@ ChangeStatus Attributor::run(Module &M) {
   return ManifestChange;
 }
 
+void Attributor::initializeInformationCache(Function &F) {
+
+  // Walk all instructions to find interesting instructions that might be
+  // queried by abstract attributes during their initialization or update.
+  // This has to happen before we create attributes.
+  auto &ReadOrWriteInsts = InfoCache.FuncRWInstsMap[&F];
+  auto &InstOpcodeMap = InfoCache.FuncInstOpcodeMap[&F];
+
+  for (Instruction &I : instructions(&F)) {
+    bool IsInterestingOpcode = false;
+
+    // To allow easy access to all instructions in a function with a given
+    // opcode we store them in the InfoCache. As not all opcodes are interesting
+    // to concrete attributes we only cache the ones that are as identified in
+    // the following switch.
+    // Note: There are no concrete attributes now so this is initially empty.
+    switch (I.getOpcode()) {
+    default:
+      assert((!ImmutableCallSite(&I)) && (!isa<CallBase>(&I)) &&
+             "New call site/base instruction type needs to be known int the "
+             "Attributor.");
+      break;
+    case Instruction::Load:
+      // The alignment of a pointer is interesting for loads.
+    case Instruction::Store:
+      // The alignment of a pointer is interesting for stores.
+    case Instruction::Call:
+    case Instruction::CallBr:
+    case Instruction::Invoke:
+    case Instruction::CleanupRet:
+    case Instruction::CatchSwitch:
+    case Instruction::Resume:
+    case Instruction::Ret:
+      IsInterestingOpcode = true;
+    }
+    if (IsInterestingOpcode)
+      InstOpcodeMap[I.getOpcode()].push_back(&I);
+    if (I.mayReadOrWriteMemory())
+      ReadOrWriteInsts.push_back(&I);
+  }
+}
+
 void Attributor::identifyDefaultAbstractAttributes(Function &F) {
   if (!VisitedFunctions.insert(&F).second)
     return;
@@ -3935,52 +3989,9 @@ void Attributor::identifyDefaultAbstractAttributes(Function &F) {
     }
   }
 
-  // Walk all instructions to find more attribute opportunities and also
-  // interesting instructions that might be queried by abstract attributes
-  // during their initialization or update.
-  auto &ReadOrWriteInsts = InfoCache.FuncRWInstsMap[&F];
-  auto &InstOpcodeMap = InfoCache.FuncInstOpcodeMap[&F];
-
-  for (Instruction &I : instructions(&F)) {
-    bool IsInterestingOpcode = false;
-
-    // To allow easy access to all instructions in a function with a given
-    // opcode we store them in the InfoCache. As not all opcodes are interesting
-    // to concrete attributes we only cache the ones that are as identified in
-    // the following switch.
-    // Note: There are no concrete attributes now so this is initially empty.
-    switch (I.getOpcode()) {
-    default:
-      assert((!ImmutableCallSite(&I)) && (!isa<CallBase>(&I)) &&
-             "New call site/base instruction type needs to be known int the "
-             "attributor.");
-      break;
-    case Instruction::Load:
-      // The alignment of a pointer is interesting for loads.
-      getOrCreateAAFor<AAAlign>(
-          IRPosition::value(*cast<LoadInst>(I).getPointerOperand()));
-      break;
-    case Instruction::Store:
-      // The alignment of a pointer is interesting for stores.
-      getOrCreateAAFor<AAAlign>(
-          IRPosition::value(*cast<StoreInst>(I).getPointerOperand()));
-      break;
-    case Instruction::Call:
-    case Instruction::CallBr:
-    case Instruction::Invoke:
-    case Instruction::CleanupRet:
-    case Instruction::CatchSwitch:
-    case Instruction::Resume:
-    case Instruction::Ret:
-      IsInterestingOpcode = true;
-    }
-    if (IsInterestingOpcode)
-      InstOpcodeMap[I.getOpcode()].push_back(&I);
-    if (I.mayReadOrWriteMemory())
-      ReadOrWriteInsts.push_back(&I);
-
+  auto CallSitePred = [&](Instruction &I) -> bool {
     CallSite CS(&I);
-    if (CS && CS.getCalledFunction()) {
+    if (CS.getCalledFunction()) {
       for (int i = 0, e = CS.getCalledFunction()->arg_size(); i < e; i++) {
 
         IRPosition CSArgPos = IRPosition::callsite_argument(CS, i);
@@ -4004,7 +4015,32 @@ void Attributor::identifyDefaultAbstractAttributes(Function &F) {
         getOrCreateAAFor<AAAlign>(CSArgPos);
       }
     }
-  }
+    return true;
+  };
+
+  auto &OpcodeInstMap = InfoCache.getOpcodeInstMapForFunction(F);
+  bool Success, AnyDead = false;
+  Success = checkForAllInstructionsImpl(
+      OpcodeInstMap, CallSitePred, nullptr, AnyDead,
+      {(unsigned)Instruction::Invoke, (unsigned)Instruction::CallBr,
+       (unsigned)Instruction::Call});
+  (void)Success;
+  assert(Success && !AnyDead && "Expected the check call to be successful!");
+
+  auto LoadStorePred = [&](Instruction &I) -> bool {
+    if (isa<LoadInst>(I))
+      getOrCreateAAFor<AAAlign>(
+          IRPosition::value(*cast<LoadInst>(I).getPointerOperand()));
+    else
+      getOrCreateAAFor<AAAlign>(
+          IRPosition::value(*cast<StoreInst>(I).getPointerOperand()));
+    return true;
+  };
+  Success = checkForAllInstructionsImpl(
+      OpcodeInstMap, LoadStorePred, nullptr, AnyDead,
+      {(unsigned)Instruction::Load, (unsigned)Instruction::Store});
+  (void)Success;
+  assert(Success && !AnyDead && "Expected the check call to be successful!");
 }
 
 /// Helpers to ease debugging through output streams and print calls.
@@ -4078,6 +4114,9 @@ static bool runAttributorOnModule(Module &M, AnalysisGetter &AG) {
   InformationCache InfoCache(M.getDataLayout(), AG);
   Attributor A(InfoCache, DepRecInterval);
 
+  for (Function &F : M)
+    A.initializeInformationCache(F);
+
   for (Function &F : M) {
     if (F.hasExactDefinition())
       NumFnWithExactDefinition++;
diff --git a/test/Transforms/FunctionAttrs/align.ll b/test/Transforms/FunctionAttrs/align.ll
index 5e8671b64a2..fc5ffc61e8e 100644
--- a/test/Transforms/FunctionAttrs/align.ll
+++ b/test/Transforms/FunctionAttrs/align.ll
@@ -1,4 +1,4 @@
-; RUN: opt -attributor -attributor-manifest-internal -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=7 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
+; RUN: opt -attributor -attributor-manifest-internal -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=6 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 
diff --git a/test/Transforms/FunctionAttrs/arg_returned.ll b/test/Transforms/FunctionAttrs/arg_returned.ll
index 95871ff7d34..57d2713d278 100644
--- a/test/Transforms/FunctionAttrs/arg_returned.ll
+++ b/test/Transforms/FunctionAttrs/arg_returned.ll
@@ -1,5 +1,5 @@
 ; RUN: opt -functionattrs -S < %s | FileCheck %s --check-prefix=FNATTR
-; RUN: opt -attributor -attributor-manifest-internal -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=9 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
+; RUN: opt -attributor -attributor-manifest-internal -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=6 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
 ; RUN: opt -attributor -attributor-manifest-internal -attributor-disable=false -functionattrs -S < %s | FileCheck %s --check-prefix=BOTH
 ;
 ; Test cases specifically designed for the "returned" argument attribute.
diff --git a/test/Transforms/FunctionAttrs/dereferenceable.ll b/test/Transforms/FunctionAttrs/dereferenceable.ll
index 852b2a28351..d7b576f506a 100644
--- a/test/Transforms/FunctionAttrs/dereferenceable.ll
+++ b/test/Transforms/FunctionAttrs/dereferenceable.ll
@@ -1,4 +1,4 @@
-; RUN: opt -attributor -attributor-manifest-internal --attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=2 -S < %s | FileCheck %s --check-prefixes=ATTRIBUTOR
+; RUN: opt -attributor -attributor-manifest-internal --attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=1 -S < %s | FileCheck %s --check-prefixes=ATTRIBUTOR
 
 
 declare void @deref_phi_user(i32* %a);
diff --git a/test/Transforms/FunctionAttrs/fn_noreturn.ll b/test/Transforms/FunctionAttrs/fn_noreturn.ll
index d8258be7d2c..e3a0f0b2504 100644
--- a/test/Transforms/FunctionAttrs/fn_noreturn.ll
+++ b/test/Transforms/FunctionAttrs/fn_noreturn.ll
@@ -1,4 +1,4 @@
-; RUN: opt -functionattrs -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=3 -S < %s | FileCheck %s
+; RUN: opt -functionattrs -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=2 -S < %s | FileCheck %s
 ;
 ; Test cases specifically designed for the "no-return" function attribute.
 ; We use FIXME's to indicate problems and missing attributes.
diff --git a/test/Transforms/FunctionAttrs/internal-noalias.ll b/test/Transforms/FunctionAttrs/internal-noalias.ll
index edc3fe07dae..1118fa194f3 100644
--- a/test/Transforms/FunctionAttrs/internal-noalias.ll
+++ b/test/Transforms/FunctionAttrs/internal-noalias.ll
@@ -1,4 +1,4 @@
-; RUN: opt -S -passes=attributor -aa-pipeline='basic-aa' -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=6 < %s | FileCheck %s
+; RUN: opt -S -passes=attributor -aa-pipeline='basic-aa' -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=5 < %s | FileCheck %s
 
 define dso_local i32 @visible(i32* noalias %A, i32* noalias %B) #0 {
 entry:
diff --git a/test/Transforms/FunctionAttrs/liveness.ll b/test/Transforms/FunctionAttrs/liveness.ll
index 93aac999950..771c99309bb 100644
--- a/test/Transforms/FunctionAttrs/liveness.ll
+++ b/test/Transforms/FunctionAttrs/liveness.ll
@@ -1,4 +1,4 @@
-; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=11 -S < %s | FileCheck %s
+; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=2 -S < %s | FileCheck %s
 
 declare void @no_return_call() nofree noreturn nounwind readnone
 
diff --git a/test/Transforms/FunctionAttrs/noalias_returned.ll b/test/Transforms/FunctionAttrs/noalias_returned.ll
index 410d1d6cbc3..7174c3dc97c 100644
--- a/test/Transforms/FunctionAttrs/noalias_returned.ll
+++ b/test/Transforms/FunctionAttrs/noalias_returned.ll
@@ -1,4 +1,4 @@
-; RUN: opt -S -passes=attributor -aa-pipeline='basic-aa' -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=5 < %s | FileCheck %s
+; RUN: opt -S -passes=attributor -aa-pipeline='basic-aa' -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=1 < %s | FileCheck %s
 
 ; TEST 1 - negative.
 
diff --git a/test/Transforms/FunctionAttrs/nofree-attributor.ll b/test/Transforms/FunctionAttrs/nofree-attributor.ll
index bfaa98eccf7..f76b429aa4b 100644
--- a/test/Transforms/FunctionAttrs/nofree-attributor.ll
+++ b/test/Transforms/FunctionAttrs/nofree-attributor.ll
@@ -1,5 +1,5 @@
 ; RUN: opt -functionattrs --disable-nofree-inference=false -S < %s | FileCheck %s --check-prefix=FNATTR
-; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=7 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
+; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=4 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 
diff --git a/test/Transforms/FunctionAttrs/noreturn_async.ll b/test/Transforms/FunctionAttrs/noreturn_async.ll
index 1e34ca4f948..e9e423688df 100644
--- a/test/Transforms/FunctionAttrs/noreturn_async.ll
+++ b/test/Transforms/FunctionAttrs/noreturn_async.ll
@@ -1,4 +1,4 @@
-; RUN: opt -functionattrs -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=3 -S < %s | FileCheck %s
+; RUN: opt -functionattrs -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=2 -S < %s | FileCheck %s
 ;
 ; This file is the same as noreturn_sync.ll but with a personality which
 ; indicates that the exception handler *can* catch asynchronous exceptions. As
diff --git a/test/Transforms/FunctionAttrs/noreturn_sync.ll b/test/Transforms/FunctionAttrs/noreturn_sync.ll
index 4c62ea57f50..5d644965fb2 100644
--- a/test/Transforms/FunctionAttrs/noreturn_sync.ll
+++ b/test/Transforms/FunctionAttrs/noreturn_sync.ll
@@ -1,4 +1,4 @@
-; RUN: opt -functionattrs -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=5 -S < %s | FileCheck %s
+; RUN: opt -functionattrs -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=2 -S < %s | FileCheck %s
 ;
 ; This file is the same as noreturn_async.ll but with a personality which
 ; indicates that the exception handler *cannot* catch asynchronous exceptions.
diff --git a/test/Transforms/FunctionAttrs/nosync.ll b/test/Transforms/FunctionAttrs/nosync.ll
index 2807e89e986..d948048db12 100644
--- a/test/Transforms/FunctionAttrs/nosync.ll
+++ b/test/Transforms/FunctionAttrs/nosync.ll
@@ -1,5 +1,5 @@
 ; RUN: opt -functionattrs -S < %s | FileCheck %s --check-prefix=FNATTR
-; RUN: opt -attributor -attributor-manifest-internal -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=3 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
+; RUN: opt -attributor -attributor-manifest-internal -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=2 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 
 ; Test cases designed for the nosync function attribute.
diff --git a/test/Transforms/FunctionAttrs/nounwind.ll b/test/Transforms/FunctionAttrs/nounwind.ll
index 0e6b607d546..85878058922 100644
--- a/test/Transforms/FunctionAttrs/nounwind.ll
+++ b/test/Transforms/FunctionAttrs/nounwind.ll
@@ -1,5 +1,5 @@
 ; RUN: opt < %s -functionattrs -S | FileCheck %s
-; RUN: opt < %s -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=5 -S | FileCheck %s --check-prefix=ATTRIBUTOR
+; RUN: opt < %s -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=2 -S | FileCheck %s --check-prefix=ATTRIBUTOR
 
 ; TEST 1
 ; CHECK: Function Attrs: norecurse nounwind readnone
diff --git a/test/Transforms/FunctionAttrs/willreturn.ll b/test/Transforms/FunctionAttrs/willreturn.ll
index 1b9b3c91b31..7821658c952 100644
--- a/test/Transforms/FunctionAttrs/willreturn.ll
+++ b/test/Transforms/FunctionAttrs/willreturn.ll
@@ -1,5 +1,5 @@
 ; RUN: opt -functionattrs -S < %s | FileCheck %s --check-prefix=FNATTR
-; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=7 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
+; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=2 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
 
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"