Use a map to cache the ModuleType information, so we can do logarithmic

lookups instead of linear time lookups.  This speeds up bc parsing of a
large file from

137.834u 118.256s 4:27.96
to
132.611u 114.436s 4:08.53

with a release build.

llvm-svn: 23611

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/Bytecode/Reader/Reader.h b/llvm/lib/Bytecode/Reader/Reader.h
index eec5de98493..df0ddca7472 100644
--- a/llvm/lib/Bytecode/Reader/Reader.h
+++ b/llvm/lib/Bytecode/Reader/Reader.h
@@ -333,6 +333,12 @@ private:
   /// @brief This vector is used to deal with forward references to types in
   /// a module.
   TypeListTy ModuleTypes;
+  
+  /// @brief This is an inverse mapping of ModuleTypes from the type to an
+  /// index.  Because refining types causes the index of this map to be
+  /// invalidated, any time we refine a type, we clear this cache and recompute
+  /// it next time we need it.  These entries are ordered by the pointer value.
+  std::vector<std::pair<const Type*, unsigned> > ModuleTypeIDCache;
 
   /// @brief This vector is used to deal with forward references to types in
   /// a function.