The inliner was choosing to not consider call sites

that appear in the SCC as a result of inlining as candidates
for inlining.  Change this so that it *does* consider call 
sites that change from being indirect to being direct as a
result of inlining.  This allows it to completely 
"devirtualize" the testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102146 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 14 insertions, 3 deletions

diff --git a/lib/Transforms/IPO/Inliner.cpp b/lib/Transforms/IPO/Inliner.cpp
index 19b65e8e1f..1de7b0753d 100644
--- a/lib/Transforms/IPO/Inliner.cpp
+++ b/lib/Transforms/IPO/Inliner.cpp
@@ -383,11 +383,17 @@ bool Inliner::runOnSCC(CallGraphSCC &SCC) {
         if (!shouldInline(CS))
           continue;
 
-        // Attempt to inline the function...
+        // Attempt to inline the function.
         if (!InlineCallIfPossible(CS, InlineInfo, InlinedArrayAllocas))
           continue;
         ++NumInlined;
 
+        // If inlining this function devirtualized any call sites, throw them
+        // onto our worklist to process.  They are useful inline candidates.
+        for (unsigned i = 0, e = InlineInfo.DevirtualizedCalls.size();
+             i != e; ++i)
+          CallSites.push_back(CallSite(InlineInfo.DevirtualizedCalls[i]));
+        
         // Update the cached cost info with the inlined call.
         growCachedCostInfo(Caller, Callee);
       }
diff --git a/lib/Transforms/Utils/InlineFunction.cpp b/lib/Transforms/Utils/InlineFunction.cpp
index 5629a38709..a913d157e2 100644
--- a/lib/Transforms/Utils/InlineFunction.cpp
+++ b/lib/Transforms/Utils/InlineFunction.cpp
@@ -170,7 +170,8 @@ static void HandleInlinedInvoke(InvokeInst *II, BasicBlock *FirstNewBlock,
 static void UpdateCallGraphAfterInlining(CallSite CS,
                                          Function::iterator FirstNewBlock,
                                        DenseMap<const Value*, Value*> &ValueMap,
-                                         CallGraph &CG) {
+                                         InlineFunctionInfo &IFI) {
+  CallGraph &CG = *IFI.CG;
   const Function *Caller = CS.getInstruction()->getParent()->getParent();
   const Function *Callee = CS.getCalledFunction();
   CallGraphNode *CalleeNode = CG[Callee];
@@ -210,6 +211,10 @@ static void UpdateCallGraphAfterInlining(CallSite CS,
       if (Function *F = CallSite(NewCall).getCalledFunction()) {
         // Indirect call site resolved to direct call.
         CallerNode->addCalledFunction(CallSite::get(NewCall), CG[F]);
+        
+        // Remember that this callsite got devirtualized for the client of
+        // InlineFunction.
+        IFI.DevirtualizedCalls.push_back(NewCall);
         continue;
       }
     
@@ -362,7 +367,7 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI) {
 
     // Update the callgraph if requested.
     if (IFI.CG)
-      UpdateCallGraphAfterInlining(CS, FirstNewBlock, ValueMap, *IFI.CG);
+      UpdateCallGraphAfterInlining(CS, FirstNewBlock, ValueMap, IFI);
   }
 
   // If there are any alloca instructions in the block that used to be the entry