[llvm] 16188f9 - [Attributor][FIX] Do not create new calls edge we cannot handle

[Johannes Doerfert via llvm-commits]

Author: Johannes Doerfert
Date: 2020-02-19T22:33:51-06:00
New Revision: 16188f9d70d77ca9ff1d1d2ff2db64479341e9bf

URL: https://github.com/llvm/llvm-project/commit/16188f9d70d77ca9ff1d1d2ff2db64479341e9bf
DIFF: https://github.com/llvm/llvm-project/commit/16188f9d70d77ca9ff1d1d2ff2db64479341e9bf.diff

LOG: [Attributor][FIX] Do not create new calls edge we cannot handle

If we propagate function pointers across function boundaries we can
create new call edges. These need to be represented in the CG if we run
as a CGSCC pass. In the new pass manager that is currently not handled
by the CallGraphUpdater so we need to prevent the situation for now.

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Transforms/IPO/Attributor.h b/llvm/include/llvm/Transforms/IPO/Attributor.h
index 54a980523d28..2fd5f59efa66 100644
--- a/llvm/include/llvm/Transforms/IPO/Attributor.h
+++ b/llvm/include/llvm/Transforms/IPO/Attributor.h
@@ -775,6 +775,12 @@ struct Attributor {
   /// Return the internal information cache.
   InformationCache &getInfoCache() { return InfoCache; }
 
+  /// Return true if this is a module pass, false otherwise.
+  bool isModulePass() const {
+    return !Functions.empty() &&
+           Functions.size() == Functions.front()->getParent()->size();
+  }
+
   /// Determine opportunities to derive 'default' attributes in \p F and create
   /// abstract attribute objects for them.
   ///

diff  --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
index f089ba7ce93e..7d6ea0fa2db4 100644
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -4577,6 +4577,17 @@ struct AAValueSimplifyArgument final : AAValueSimplifyImpl {
     if (hasAttr({Attribute::InAlloca, Attribute::StructRet, Attribute::Nest},
                 /* IgnoreSubsumingPositions */ true))
       indicatePessimisticFixpoint();
+
+    // FIXME: This is a hack to prevent us from propagating function poiner in
+    // the new pass manager CGSCC pass as it creates call edges the
+    // CallGraphUpdater cannot handle yet.
+    Value &V = getAssociatedValue();
+    if (V.getType()->isPointerTy() &&
+        V.getType()->getPointerElementType()->isFunctionTy() &&
+        !A.isModulePass() &&
+        A.getInfoCache().getAnalysisResultForFunction<LoopAnalysis>(
+            *getAnchorScope()))
+      indicatePessimisticFixpoint();
   }
 
   /// See AbstractAttribute::updateImpl(...).
@@ -4700,6 +4711,7 @@ struct AAValueSimplifyFloating : AAValueSimplifyImpl {
 
   /// See AbstractAttribute::initialize(...).
   void initialize(Attributor &A) override {
+    AAValueSimplifyImpl::initialize(A);
     Value &V = getAnchorValue();
 
     // TODO: add other stuffs