Switch ComputeTopDownOrdering over to using a densemap. This speeds up
isel as a whole by 3.3%.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33809 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 6aa1360..22edbf3 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -25,6 +25,7 @@
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
+#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
#include <map>
using namespace llvm;
@@ -290,7 +291,7 @@
/// ComputeTopDownOrdering - Add the specified node to the Order list if it has
/// not been visited yet and if all of its operands have already been visited.
static void ComputeTopDownOrdering(SDNode *N, std::vector<SDNode*> &Order,
- std::map<SDNode*, unsigned> &Visited) {
+ DenseMap<SDNode*, unsigned> &Visited) {
if (++Visited[N] != N->getNumOperands())
return; // Haven't visited all operands yet
@@ -318,7 +319,7 @@
// practice however, this causes us to run out of stack space on large basic
// blocks. To avoid this problem, compute an ordering of the nodes where each
// node is only legalized after all of its operands are legalized.
- std::map<SDNode*, unsigned> Visited;
+ DenseMap<SDNode*, unsigned> Visited;
std::vector<SDNode*> Order;
// Compute ordering from all of the leaves in the graphs, those (like the