Speed up these passes when the callgraph has
huge simply connected components. Suggested
by Chris.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56787 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/AddReadAttrs.cpp b/lib/Transforms/IPO/AddReadAttrs.cpp
index b70bdaf..4c6158c 100644
--- a/lib/Transforms/IPO/AddReadAttrs.cpp
+++ b/lib/Transforms/IPO/AddReadAttrs.cpp
@@ -19,6 +19,7 @@
#include "llvm/CallGraphSCCPass.h"
#include "llvm/Instructions.h"
#include "llvm/Analysis/CallGraph.h"
+#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/InstIterator.h"
@@ -45,8 +46,14 @@
bool AddReadAttrs::runOnSCC(const std::vector<CallGraphNode *> &SCC) {
+ SmallPtrSet<CallGraphNode *, 8> SCCNodes;
CallGraph &CG = getAnalysis<CallGraph>();
+ // Fill SCCNodes with the elements of the SCC. Used for quickly
+ // looking up whether a given CallGraphNode is in this SCC.
+ for (unsigned i = 0, e = SCC.size(); i != e; ++i)
+ SCCNodes.insert(SCC[i]);
+
// Check if any of the functions in the SCC read or write memory. If they
// write memory then they can't be marked readnone or readonly.
bool ReadsMemory = false;
@@ -77,9 +84,7 @@
CallSite CS = CallSite::get(&*II);
// Ignore calls to functions in the same SCC.
- if (CS.getInstruction() &&
- std::find(SCC.begin(), SCC.end(), CG[CS.getCalledFunction()]) !=
- SCC.end())
+ if (CS.getInstruction() && SCCNodes.count(CG[CS.getCalledFunction()]))
continue;
if (II->mayWriteToMemory())