[llvm-commits] [llvm] r132862 - /llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp

[Dan Gohman]

Author: djg
Date: Fri Jun 10 17:30:30 2011
New Revision: 132862

URL: http://llvm.org/viewvc/llvm-project?rev=132862&view=rev
Log:
Initialize BasicAA's AliasCache to set it to use fewer buckets by
default, since it usually has very few elements. This speeds up
alias queries in many cases, because AliasCache.clear() doesn't
have to visit as many buckets.

Modified:
    llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp

Modified: llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp?rev=132862&r1=132861&r2=132862&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp Fri Jun 10 17:30:30 2011
@@ -451,7 +451,13 @@
   /// BasicAliasAnalysis - This is the primary alias analysis implementation.
   struct BasicAliasAnalysis : public ImmutablePass, public AliasAnalysis {
     static char ID; // Class identification, replacement for typeinfo
-    BasicAliasAnalysis() : ImmutablePass(ID) {
+    BasicAliasAnalysis() : ImmutablePass(ID),
+                           // AliasCache rarely has more than 1 or 2 elements,
+                           // so start it off fairly small so that clear()
+                           // doesn't have to tromp through 64 (the default)
+                           // elements on each alias query. This really wants
+                           // something like a SmallDenseMap.
+                           AliasCache(8) {
       initializeBasicAliasAnalysisPass(*PassRegistry::getPassRegistry());
     }