Cache non-local memory dependence analysis. This is a significant compile
time performance win in most cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41126 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp
index 605dca1..11a8009 100644
--- a/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -203,6 +203,11 @@
/// blocks between the query and its dependencies.
void MemoryDependenceAnalysis::getNonLocalDependency(Instruction* query,
DenseMap<BasicBlock*, Value*>& resp) {
+ if (depGraphNonLocal.count(query)) {
+ resp = depGraphNonLocal[query];
+ return;
+ }
+
// First check that we don't actually have a local dependency.
Instruction* localDep = getDependency(query);
if (localDep != NonLocal) {
@@ -212,6 +217,13 @@
// If not, go ahead and search for non-local ones.
nonLocalHelper(query, query->getParent(), resp);
+
+ // Update the non-local dependency cache
+ for (DenseMap<BasicBlock*, Value*>::iterator I = resp.begin(), E = resp.end();
+ I != E; ++I) {
+ depGraphNonLocal[query].insert(*I);
+ reverseDepNonLocal[I->second].insert(query);
+ }
}
/// getDependency - Return the instruction on which a memory operation
@@ -380,8 +392,6 @@
Instruction* newDep = NonLocal;
depMapType::iterator depGraphEntry = depGraphLocal.find(rem);
- // We assume here that it's not in the reverse map if it's not in
- // the dep map. Checking it could be expensive, so don't do it.
if (depGraphEntry != depGraphLocal.end()) {
if (depGraphEntry->second.first != NonLocal &&
@@ -410,8 +420,18 @@
// Mark it as unconfirmed as long as it is not the non-local flag
depGraphLocal[*I] = std::make_pair(newDep, !newDep);
}
+
reverseDep.erase(rem);
}
+
+ if (depGraphNonLocal.count(rem)) {
+ SmallPtrSet<Instruction*, 4>& set = reverseDepNonLocal[rem];
+ for (SmallPtrSet<Instruction*, 4>::iterator I = set.begin(), E = set.end();
+ I != E; ++I)
+ depGraphNonLocal.erase(*I);
+
+ reverseDepNonLocal.erase(rem);
+ }
getAnalysis<AliasAnalysis>().deleteValue(rem);
}