From aad4c9fc37b38cae21343173084c81d789535446 Mon Sep 17 00:00:00 2001
From: David Greene <greened@obbligato.org>
Date: Fri, 29 Jul 2011 19:07:16 +0000
Subject: [PATCH] [AVX] Make ListInits Unique

Ensure ListInits are unique and only created once.  This will be
important for AVX as lists will be used extensively to pass generic
patterns, prefix information and other things to lower-level
pattern-generation classes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136493 91177308-0d34-0410-b5e6-96231b3b80d8
---
 utils/TableGen/Record.cpp | 37 ++++++++++++++++++++++++++++++++++++-
 utils/TableGen/Record.h   | 10 +++++-----
 2 files changed, 41 insertions(+), 6 deletions(-)

diff --git a/utils/TableGen/Record.cpp b/utils/TableGen/Record.cpp
index 133a1581c0e..4608d7aa149 100644
--- a/utils/TableGen/Record.cpp
+++ b/utils/TableGen/Record.cpp
@@ -583,8 +583,43 @@ const CodeInit *CodeInit::get(const std::string &V) {
   return I;
 }
 
+static void ProfileListInit(FoldingSetNodeID &ID,
+                            ArrayRef<const Init *> Range,
+                            RecTy *EltTy) {
+  ID.AddInteger(Range.size());
+  ID.AddPointer(EltTy);
+
+  for (ArrayRef<const Init *>::iterator i = Range.begin(),
+         iend = Range.end();
+       i != iend;
+       ++i)
+    ID.AddPointer(*i);
+}
+
 const ListInit *ListInit::get(ArrayRef<const Init *> Range, RecTy *EltTy) {
-  return new ListInit(Range, EltTy);
+  typedef FoldingSet<ListInit> Pool;
+  static Pool ThePool;
+
+  // Just use the FoldingSetNodeID to compute a hash.  Use a DenseMap
+  // for actual storage.
+  FoldingSetNodeID ID;
+  ProfileListInit(ID, Range, EltTy);
+
+  void *IP = 0;
+  if (const ListInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
+    return I;
+
+  ListInit *I = new ListInit(Range, EltTy);
+  ThePool.InsertNode(I, IP);
+  return I;
+}
+
+void ListInit::Profile(FoldingSetNodeID &ID) const {
+  ListRecTy *ListType = dynamic_cast<ListRecTy *>(getType());
+  assert(ListType && "Bad type for ListInit!");
+  RecTy *EltTy = ListType->getElementType();
+
+  ProfileListInit(ID, Values, EltTy);
 }
 
 const Init *
diff --git a/utils/TableGen/Record.h b/utils/TableGen/Record.h
index e70cad1a324..cbde0e9bdbc 100644
--- a/utils/TableGen/Record.h
+++ b/utils/TableGen/Record.h
@@ -1,3 +1,4 @@
+
 //===- Record.h - Classes to represent Table Records ------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
@@ -801,15 +802,12 @@ public:
 
 /// ListInit - [AL, AH, CL] - Represent a list of defs
 ///
-class ListInit : public TypedInit {
+class ListInit : public TypedInit, public FoldingSetNode {
   std::vector<const Init*> Values;
 public:
   typedef std::vector<const Init*>::const_iterator const_iterator;
 
-  explicit ListInit(std::vector<const Init*> &Vs, RecTy *EltTy)
-    : TypedInit(ListRecTy::get(EltTy)) {
-    Values.swap(Vs);
-  }
+private:
   explicit ListInit(ArrayRef<const Init *> Range, RecTy *EltTy)
       : TypedInit(ListRecTy::get(EltTy)), Values(Range.begin(), Range.end()) {}
 
@@ -819,6 +817,8 @@ public:
 public:
   static const ListInit *get(ArrayRef<const Init *> Range, RecTy *EltTy);
 
+  void Profile(FoldingSetNodeID &ID) const;
+
   unsigned getSize() const { return Values.size(); }
   const Init *getElement(unsigned i) const {
     assert(i < Values.size() && "List element index out of range!");
-- 
2.34.1