Use a cheaper test, delaying calling find_leader() until we know that it's necessary. This improves
the time to optimize Anton's testcase from 21.1s to 17.6s.
llvm-svn: 38479
diff --git a/llvm/lib/Transforms/Scalar/GVNPRE.cpp b/llvm/lib/Transforms/Scalar/GVNPRE.cpp
index 4a5dca9..007c677 100644
--- a/llvm/lib/Transforms/Scalar/GVNPRE.cpp
+++ b/llvm/lib/Transforms/Scalar/GVNPRE.cpp
@@ -565,6 +565,7 @@
bool insert(Value* v) { return contents.insert(v); }
void insert(iterator I, iterator E) { contents.insert(I, E); }
void erase(Value* v) { contents.erase(v); }
+ unsigned count(Value* v) { return contents.count(v); }
size_t size() { return contents.size(); }
void set(unsigned i) {
@@ -1173,15 +1174,16 @@
isa<ShuffleVectorInst>(BI) || isa<InsertElementInst>(BI) ||
isa<ExtractElementInst>(BI) || isa<SelectInst>(BI) ||
isa<CastInst>(BI) || isa<GetElementPtrInst>(BI)) {
- Value *leader = find_leader(availableOut[BB], VN.lookup(BI));
-
- if (leader != 0)
+
+ if (availableOut[BB].test(VN.lookup(BI)) && ! availableOut[BB].count(BI)) {
+ Value *leader = find_leader(availableOut[BB], VN.lookup(BI));
if (Instruction* Instr = dyn_cast<Instruction>(leader))
if (Instr->getParent() != 0 && Instr != BI) {
replace.push_back(std::make_pair(BI, leader));
erase.push_back(BI);
++NumEliminated;
}
+ }
}
}
}