From 3548ea8e905269e819fdd4c7fab42142b745c6c5 Mon Sep 17 00:00:00 2001
From: Duncan Sands <baldrick@free.fr>
Date: Sat, 26 Sep 2009 15:35:35 +0000
Subject: [PATCH] For the NSWSub support in the builder to actually be useable,
 there need to be corresponding changes to the constant folders, done in this
 patch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82862 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Constants.h              | 1 +
 include/llvm/Support/ConstantFolder.h | 3 +++
 include/llvm/Support/NoFolder.h       | 3 +++
 include/llvm/Support/TargetFolder.h   | 3 +++
 lib/VMCore/Constants.cpp              | 5 +++++
 5 files changed, 15 insertions(+)

diff --git a/include/llvm/Constants.h b/include/llvm/Constants.h
index 4999998078b..260a89a2d38 100644
--- a/include/llvm/Constants.h
+++ b/include/llvm/Constants.h
@@ -654,6 +654,7 @@ public:
   static Constant *getBitCast (Constant *C, const Type *Ty);
 
   static Constant* getNSWAdd(Constant* C1, Constant* C2);
+  static Constant* getNSWSub(Constant* C1, Constant* C2);
   static Constant* getExactSDiv(Constant* C1, Constant* C2);
 
   /// Transparently provide more efficient getOperand methods.
diff --git a/include/llvm/Support/ConstantFolder.h b/include/llvm/Support/ConstantFolder.h
index 3c9278aaa7a..99cb92078f3 100644
--- a/include/llvm/Support/ConstantFolder.h
+++ b/include/llvm/Support/ConstantFolder.h
@@ -44,6 +44,9 @@ public:
   Constant *CreateSub(Constant *LHS, Constant *RHS) const {
     return ConstantExpr::getSub(LHS, RHS);
   }
+  Constant *CreateNSWSub(Constant *LHS, Constant *RHS) const {
+    return ConstantExpr::getNSWSub(LHS, RHS);
+  }
   Constant *CreateFSub(Constant *LHS, Constant *RHS) const {
     return ConstantExpr::getFSub(LHS, RHS);
   }
diff --git a/include/llvm/Support/NoFolder.h b/include/llvm/Support/NoFolder.h
index 4540f028cee..1f671c19250 100644
--- a/include/llvm/Support/NoFolder.h
+++ b/include/llvm/Support/NoFolder.h
@@ -51,6 +51,9 @@ public:
   Value *CreateSub(Constant *LHS, Constant *RHS) const {
     return BinaryOperator::CreateSub(LHS, RHS);
   }
+  Value *CreateNSWSub(Constant *LHS, Constant *RHS) const {
+    return BinaryOperator::CreateNSWSub(LHS, RHS);
+  }
   Value *CreateFSub(Constant *LHS, Constant *RHS) const {
     return BinaryOperator::CreateFSub(LHS, RHS);
   }
diff --git a/include/llvm/Support/TargetFolder.h b/include/llvm/Support/TargetFolder.h
index 77533c00b13..8e28632b7eb 100644
--- a/include/llvm/Support/TargetFolder.h
+++ b/include/llvm/Support/TargetFolder.h
@@ -60,6 +60,9 @@ public:
   Constant *CreateSub(Constant *LHS, Constant *RHS) const {
     return Fold(ConstantExpr::getSub(LHS, RHS));
   }
+  Constant *CreateNSWSub(Constant *LHS, Constant *RHS) const {
+    return Fold(ConstantExpr::getNSWSub(LHS, RHS));
+  }
   Constant *CreateFSub(Constant *LHS, Constant *RHS) const {
     return Fold(ConstantExpr::getFSub(LHS, RHS));
   }
diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index ecaf9ab1633..eb7e7c05fbf 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -643,6 +643,11 @@ Constant* ConstantExpr::getNSWAdd(Constant* C1, Constant* C2) {
                OverflowingBinaryOperator::NoSignedWrap);
 }
 
+Constant* ConstantExpr::getNSWSub(Constant* C1, Constant* C2) {
+  return getTy(C1->getType(), Instruction::Sub, C1, C2,
+               OverflowingBinaryOperator::NoSignedWrap);
+}
+
 Constant* ConstantExpr::getExactSDiv(Constant* C1, Constant* C2) {
   return getTy(C1->getType(), Instruction::SDiv, C1, C2,
                SDivOperator::IsExact);