[llvm] 7df434e - [TableGen] Avoid vector copy in TreePatter::InlinePatternFragments. NFC

[Craig Topper via llvm-commits]

Author: Craig Topper
Date: 2023-04-10T23:01:15-07:00
New Revision: 7df434e3ffebf5cb8b61c8028a9c53dc91bb60e0

URL: https://github.com/llvm/llvm-project/commit/7df434e3ffebf5cb8b61c8028a9c53dc91bb60e0
DIFF: https://github.com/llvm/llvm-project/commit/7df434e3ffebf5cb8b61c8028a9c53dc91bb60e0.diff

LOG: [TableGen] Avoid vector copy in TreePatter::InlinePatternFragments. NFC

Instead of copying a vector and clearing the original, we can swap
with an empty vector.

Added: 
    

Modified: 
    llvm/utils/TableGen/CodeGenDAGPatterns.h

Removed: 
    


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diff  --git a/llvm/utils/TableGen/CodeGenDAGPatterns.h b/llvm/utils/TableGen/CodeGenDAGPatterns.h
index 154c9f1ede4db..1fb7100eb4aa3 100644
--- a/llvm/utils/TableGen/CodeGenDAGPatterns.h
+++ b/llvm/utils/TableGen/CodeGenDAGPatterns.h
@@ -948,10 +948,10 @@ class TreePattern {
   /// PatFrags references.  This may increase the number of trees in the
   /// pattern if a PatFrags has multiple alternatives.
   void InlinePatternFragments() {
-    std::vector<TreePatternNodePtr> Copy = Trees;
-    Trees.clear();
-    for (unsigned i = 0, e = Copy.size(); i != e; ++i)
-      Copy[i]->InlinePatternFragments(Copy[i], *this, Trees);
+    std::vector<TreePatternNodePtr> Copy;
+    Trees.swap(Copy);
+    for (const TreePatternNodePtr &C : Copy)
+      TreePatternNode::InlinePatternFragments(C, *this, Trees);
   }
 
   /// InferAllTypes - Infer/propagate as many types throughout the expression