This patch aims to reduce compile time in LegalizeTypes by using SmallDenseMap,

with an initial number of elements,  instead of DenseMap, which has
zero initial elements, in order to avoid the copying of elements
when the size changes and to avoid allocating space every time
LegalizeTypes is run. This patch will not affect the memory footprint,
because DenseMap will increase the element size to 64
when the first element is added.

Patch by Wan Xiaofei.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173448 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 8 deletions

diff --git a/lib/CodeGen/SelectionDAG/LegalizeTypes.h b/lib/CodeGen/SelectionDAG/LegalizeTypes.h
index 724fdb9bc1..7de42ea012 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeTypes.h
+++ b/lib/CodeGen/SelectionDAG/LegalizeTypes.h
@@ -80,35 +80,35 @@ private:
 
   /// PromotedIntegers - For integer nodes that are below legal width, this map
   /// indicates what promoted value to use.
-  DenseMap<SDValue, SDValue> PromotedIntegers;
+  SmallDenseMap<SDValue, SDValue, 8> PromotedIntegers;
 
   /// ExpandedIntegers - For integer nodes that need to be expanded this map
   /// indicates which operands are the expanded version of the input.
-  DenseMap<SDValue, std::pair<SDValue, SDValue> > ExpandedIntegers;
+  SmallDenseMap<SDValue, std::pair<SDValue, SDValue>, 8> ExpandedIntegers;
 
   /// SoftenedFloats - For floating point nodes converted to integers of
   /// the same size, this map indicates the converted value to use.
-  DenseMap<SDValue, SDValue> SoftenedFloats;
+  SmallDenseMap<SDValue, SDValue, 8> SoftenedFloats;
 
   /// ExpandedFloats - For float nodes that need to be expanded this map
   /// indicates which operands are the expanded version of the input.
-  DenseMap<SDValue, std::pair<SDValue, SDValue> > ExpandedFloats;
+  SmallDenseMap<SDValue, std::pair<SDValue, SDValue>, 8> ExpandedFloats;
 
   /// ScalarizedVectors - For nodes that are <1 x ty>, this map indicates the
   /// scalar value of type 'ty' to use.
-  DenseMap<SDValue, SDValue> ScalarizedVectors;
+  SmallDenseMap<SDValue, SDValue, 8> ScalarizedVectors;
 
   /// SplitVectors - For nodes that need to be split this map indicates
   /// which operands are the expanded version of the input.
-  DenseMap<SDValue, std::pair<SDValue, SDValue> > SplitVectors;
+  SmallDenseMap<SDValue, std::pair<SDValue, SDValue>, 8> SplitVectors;
 
   /// WidenedVectors - For vector nodes that need to be widened, indicates
   /// the widened value to use.
-  DenseMap<SDValue, SDValue> WidenedVectors;
+  SmallDenseMap<SDValue, SDValue, 8> WidenedVectors;
 
   /// ReplacedValues - For values that have been replaced with another,
   /// indicates the replacement value to use.
-  DenseMap<SDValue, SDValue> ReplacedValues;
+  SmallDenseMap<SDValue, SDValue, 8> ReplacedValues;
 
   /// Worklist - This defines a worklist of nodes to process.  In order to be
   /// pushed onto this worklist, all operands of a node must have already been