[TableGen] Early exit from ExpandHwModeBasedTypes when there are no HwModes.

Most targets don't use HwModes. For these targets we can skip
collecting the HwModes and copying all the pattern pointers.

diff --git a/llvm/utils/TableGen/CodeGenDAGPatterns.cpp b/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
index f861caa..2d8b52c 100644 (file)
--- a/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
+++ b/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
@@ -4381,6 +4381,9 @@ static void collectModes(std::set<unsigned> &Modes, const TreePatternNode *N) {
 
 void CodeGenDAGPatterns::ExpandHwModeBasedTypes() {
   const CodeGenHwModes &CGH = getTargetInfo().getHwModes();
+  if (CGH.getNumModeIds() == 1)
+    return;
+
   std::vector<PatternToMatch> Copy;
   PatternsToMatch.swap(Copy);