From: Ted Kremenek <kremenek@apple.com>
Date: Wed, 18 Feb 2009 17:42:44 +0000 (+0000)
Subject: Revise comment. Comparing pointer values in 'Range' wasn't the performance issue... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e53f8206ebb36a17e95e64270704e2608d1796f4;p=clang

Revise comment. Comparing pointer values in 'Range' wasn't the performance issue I thought it was, but it is still worth ordering Range objects by their APSInt values.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64921 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/RangeConstraintManager.cpp b/lib/Analysis/RangeConstraintManager.cpp
index 59e91c1c87..fabc57950f 100644
--- a/lib/Analysis/RangeConstraintManager.cpp
+++ b/lib/Analysis/RangeConstraintManager.cpp
@@ -62,11 +62,9 @@ public:
 class VISIBILITY_HIDDEN RangeTrait : public llvm::ImutContainerInfo<Range> {
 public:
   // When comparing if one Range is less than another, we should compare
-  // the actual APSInt values instead of their pointers.  This ensures that
-  // ImmutableSets based on Range objects always are constructed
-  // with the same ordering between Ranges.  The definition if 'isEqual' can
-  // remain as it is (compare pointers) because all APSInt objects within
-  // Range are uniqued by BasicValueManager.
+  // the actual APSInt values instead of their pointers.  This keeps the order
+  // consistent (instead of comparing by pointer values) and can potentially
+  // be used to speed up some of the operations in RangeSet.
   static inline bool isLess(key_type_ref lhs, key_type_ref rhs) {
     return *lhs.first < *rhs.first || (!(*rhs.first < *lhs.first) && 
                                        *lhs.second < *rhs.second);