[Attributor][FIX] Indicate a missing update change

User of AAReturnedValues need to know if HasOverdefinedReturnedCalls
changed from false to true as it will impact the result of the return
value traversal (calls are not ignored anymore).

This will be tested with the tests in D59978.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@367581 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/IPO/Attributor.cpp b/lib/Transforms/IPO/Attributor.cpp
index 6a7e76ab720bb46cd385f026311435706840f524..d8b8fe23036ba45af45a56a4477642b9fcbc7d88 100644 (file)
--- a/lib/Transforms/IPO/Attributor.cpp
+++ b/lib/Transforms/IPO/Attributor.cpp
@@ -722,6 +722,9 @@ ChangeStatus AAReturnedValuesImpl::updateImpl(Attributor &A) {
   decltype(ReturnedValues) AddRVs;
   bool HasCallSite = false;
 
+  // Keep track of any change to trigger updates on dependent attributes.
+  ChangeStatus Changed = ChangeStatus::UNCHANGED;
+
   // Look at all returned call sites.
   for (auto &It : ReturnedValues) {
     SmallPtrSet<ReturnInst *, 2> &ReturnInsts = It.second;
@@ -742,6 +745,8 @@ ChangeStatus AAReturnedValuesImpl::updateImpl(Attributor &A) {
     // Try to find a assumed unique return value for the called function.
     auto *RetCSAA = A.getAAFor<AAReturnedValuesImpl>(*this, *RV);
     if (!RetCSAA) {
+      if (!HasOverdefinedReturnedCalls)
+        Changed = ChangeStatus::CHANGED;
       HasOverdefinedReturnedCalls = true;
       LLVM_DEBUG(dbgs() << "[AAReturnedValues] Returned call site (" << *RV
                         << ") with " << (RetCSAA ? "invalid" : "no")
@@ -763,6 +768,8 @@ ChangeStatus AAReturnedValuesImpl::updateImpl(Attributor &A) {
     // If multiple, non-refinable values were found, there cannot be a unique
     // return value for the called function. The returned call is overdefined!
     if (!AssumedUniqueRV.getValue()) {
+      if (!HasOverdefinedReturnedCalls)
+        Changed = ChangeStatus::CHANGED;
       HasOverdefinedReturnedCalls = true;
       LLVM_DEBUG(dbgs() << "[AAReturnedValues] Returned call site has multiple "
                            "potentially returned values\n");
@@ -791,9 +798,6 @@ ChangeStatus AAReturnedValuesImpl::updateImpl(Attributor &A) {
       AddRVs[AssumedRetVal].insert(ReturnInsts.begin(), ReturnInsts.end());
   }
 
-  // Keep track of any change to trigger updates on dependent attributes.
-  ChangeStatus Changed = ChangeStatus::UNCHANGED;
-
   for (auto &It : AddRVs) {
     assert(!It.second.empty() && "Entry does not add anything.");
     auto &ReturnInsts = ReturnedValues[It.first];