[llvm] r365983 - [Attributor] Only return attributes with a valid state

[Johannes Doerfert via llvm-commits]

Author: jdoerfert
Date: Fri Jul 12 18:09:21 2019
New Revision: 365983

URL: http://llvm.org/viewvc/llvm-project?rev=365983&view=rev
Log:
[Attributor] Only return attributes with a valid state

Attributor::getAAFor will now only return AbstractAttributes with a
valid AbstractState. This simplifies call sites as they only need to
check if the returned pointer is non-null. It also reduces the potential
for accidental misuse.

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

Modified: llvm/trunk/include/llvm/Transforms/IPO/Attributor.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/IPO/Attributor.h?rev=365983&r1=365982&r2=365983&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/IPO/Attributor.h (original)
+++ llvm/trunk/include/llvm/Transforms/IPO/Attributor.h Fri Jul 12 18:09:21 2019
@@ -199,8 +199,12 @@ struct Attributor {
     const auto &KindToAbstractAttributeMap = AAMap.lookup({&V, ArgNo});
     if (AAType *AA = static_cast<AAType *>(
             KindToAbstractAttributeMap.lookup(AAType::ID))) {
-      QueryMap[AA].insert(&QueryingAA);
-      return AA;
+      // Do not return an attribute with an invalid state. This minimizes checks
+      // at the calls sites and allows the fallback below to kick in.
+      if (AA->getState().isValidState()) {
+        QueryMap[AA].insert(&QueryingAA);
+        return AA;
+      }
     }
 
     // If no abstract attribute was found and we look for a call site argument,

Modified: llvm/trunk/lib/Transforms/IPO/Attributor.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/Attributor.cpp?rev=365983&r1=365982&r2=365983&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/Attributor.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/Attributor.cpp Fri Jul 12 18:09:21 2019
@@ -655,7 +655,7 @@ ChangeStatus AAReturnedValuesImpl::updat
 
     // Try to find a assumed unique return value for the called function.
     auto *RetCSAA = A.getAAFor<AAReturnedValuesImpl>(*this, *RV);
-    if (!RetCSAA || !RetCSAA->isValidState()) {
+    if (!RetCSAA) {
       HasOverdefinedReturnedCalls = true;
       LLVM_DEBUG(dbgs() << "[AAReturnedValues] Returned call site (" << *RV
                         << ") with " << (RetCSAA ? "invalid" : "no")
@@ -965,8 +965,7 @@ ChangeStatus AANoFreeFunction::updateImp
       auto ICS = ImmutableCallSite(I);
       auto *NoFreeAA = A.getAAFor<AANoFreeFunction>(*this, *I);
 
-      if ((!NoFreeAA || !NoFreeAA->isValidState() ||
-           !NoFreeAA->isAssumedNoFree()) &&
+      if ((!NoFreeAA || !NoFreeAA->isAssumedNoFree()) &&
           !ICS.hasFnAttr(Attribute::NoFree)) {
         indicatePessimisticFixpoint();
         return ChangeStatus::CHANGED;