From 70b06fc717b65734daaa5e442a99fdc231835a84 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Fri, 3 Oct 2003 19:34:51 +0000
Subject: [PATCH] Minor random speedup: make Constant::getNullValue only call
 ConstantFOO::get once!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8845 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/VMCore/Constants.cpp | 58 +++++++++++++++++++++++++++++++---------
 1 file changed, 45 insertions(+), 13 deletions(-)

diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index c252247dd0b..8fb665ac0e1 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -59,25 +59,57 @@ void Constant::destroyConstantImpl() {
 // Static constructor to create a '0' constant of arbitrary type...
 Constant *Constant::getNullValue(const Type *Ty) {
   switch (Ty->getPrimitiveID()) {
-  case Type::BoolTyID:   return ConstantBool::get(false);
-  case Type::SByteTyID:
-  case Type::ShortTyID:
-  case Type::IntTyID:
-  case Type::LongTyID:   return ConstantSInt::get(Ty, 0);
-
-  case Type::UByteTyID:
-  case Type::UShortTyID:
-  case Type::UIntTyID:
-  case Type::ULongTyID:  return ConstantUInt::get(Ty, 0);
+  case Type::BoolTyID: {
+    static Constant *NullBool = ConstantBool::get(false);
+    return NullBool;
+  }
+  case Type::SByteTyID: {
+    static Constant *NullSByte = ConstantSInt::get(Type::SByteTy, 0);
+    return NullSByte;
+  }
+  case Type::UByteTyID: {
+    static Constant *NullUByte = ConstantUInt::get(Type::UByteTy, 0);
+    return NullUByte;
+  }
+  case Type::ShortTyID: {
+    static Constant *NullShort = ConstantSInt::get(Type::ShortTy, 0);
+    return NullShort;
+  }
+  case Type::UShortTyID: {
+    static Constant *NullUShort = ConstantUInt::get(Type::UShortTy, 0);
+    return NullUShort;
+  }
+  case Type::IntTyID: {
+    static Constant *NullInt = ConstantSInt::get(Type::IntTy, 0);
+    return NullInt;
+  }
+  case Type::UIntTyID: {
+    static Constant *NullUInt = ConstantUInt::get(Type::UIntTy, 0);
+    return NullUInt;
+  }
+  case Type::LongTyID: {
+    static Constant *NullLong = ConstantSInt::get(Type::LongTy, 0);
+    return NullLong;
+  }
+  case Type::ULongTyID: {
+    static Constant *NullULong = ConstantUInt::get(Type::ULongTy, 0);
+    return NullULong;
+  }
 
-  case Type::FloatTyID:
-  case Type::DoubleTyID: return ConstantFP::get(Ty, 0);
+  case Type::FloatTyID: {
+    static Constant *NullFloat = ConstantFP::get(Type::FloatTy, 0);
+    return NullFloat;
+  }
+  case Type::DoubleTyID: {
+    static Constant *NullDouble = ConstantFP::get(Type::DoubleTy, 0);
+    return NullDouble;
+  }
 
   case Type::PointerTyID: 
     return ConstantPointerNull::get(cast<PointerType>(Ty));
+
   case Type::StructTyID: {
     const StructType *ST = cast<StructType>(Ty);
-
     const StructType::ElementTypes &ETs = ST->getElementTypes();
     std::vector<Constant*> Elements;
     Elements.resize(ETs.size());
-- 
2.34.1