do not bother inlining nullary functions without return values. The only

effect these calls can have is due to global variables, and these passes
all use the globals graph to capture their effect anyway.  This speeds up
the BU pass very slightly on perlbmk, reducing the number of dsnodes
allocated from 98913 to 96423.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20676 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/DataStructure/BottomUpClosure.cpp

@@ -305,6 +305,13 @@ void BUDataStructures::calculateGraph(DSGraph &Graph) {
 
     CalledFuncs.clear();
 
+    // Fast path for noop calls.  Note that we don't care about merging globals
+    // in the callee with nodes in the caller here.
+    if (CS.getRetVal().isNull() && CS.getNumPtrArgs() == 0) {
+      TempFCs.erase(TempFCs.begin());
+      continue;
+    }
+
     if (CS.isDirectCall()) {
       Function *F = CS.getCalleeFunc();
       if (isResolvableFunc(F))

lib/Analysis/DataStructure/CompleteBottomUp.cpp

@@ -217,7 +217,11 @@ void CompleteBUDataStructures::processGraph(DSGraph &G) {
 
     assert(calls.insert(TheCall).second &&
            "Call instruction occurs multiple times in graph??");
-      
+    
+    // Fast path for noop calls.  Note that we don't care about merging globals
+    // in the callee with nodes in the caller here.
+    if (CS.getRetVal().isNull() && CS.getNumPtrArgs() == 0)
+      continue;
 
     // Loop over all of the potentially called functions...
     // Inline direct calls as well as indirect calls because the direct

lib/Analysis/DataStructure/EquivClassGraphs.cpp

@@ -406,6 +406,9 @@ void EquivClassGraphs::processGraph(DSGraph &G) {
     assert(calls.insert(TheCall).second &&
            "Call instruction occurs multiple times in graph??");
     
+    if (CS.getRetVal().isNull() && CS.getNumPtrArgs() == 0)
+      continue;
+
     // Inline the common callee graph into the current graph, if the callee
     // graph has not changed.  Note that all callees should have the same
     // graph so we only need to do this once.