From f341a47d10501bc69b5d4d2217992bb6e08668d8 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Sun, 29 Mar 2009 06:33:22 +0000
Subject: [PATCH] When forming sentinels for empty/tombstone, make sure to
 respect the pointer's expected number of zero low-bits.

This should fix the breakage I introduced recently.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67990 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/ADT/DenseMap.h       | 14 +++++++++++---
 include/llvm/ADT/PointerIntPair.h |  9 ++++++---
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/include/llvm/ADT/DenseMap.h b/include/llvm/ADT/DenseMap.h
index 9a66c8b6c11..c0f8cee5984 100644
--- a/include/llvm/ADT/DenseMap.h
+++ b/include/llvm/ADT/DenseMap.h
@@ -14,7 +14,7 @@
 #ifndef LLVM_ADT_DENSEMAP_H
 #define LLVM_ADT_DENSEMAP_H
 
-#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/PointerLikeTypeTraits.h"
 #include "llvm/Support/MathExtras.h"
 #include <cassert>
 #include <utility>
@@ -33,8 +33,16 @@ struct DenseMapInfo {
 // Provide DenseMapInfo for all pointers.
 template<typename T>
 struct DenseMapInfo<T*> {
-  static inline T* getEmptyKey() { return reinterpret_cast<T*>(-1); }
-  static inline T* getTombstoneKey() { return reinterpret_cast<T*>(-2); }
+  static inline T* getEmptyKey() {
+    intptr_t Val = -1;
+    Val <<= PointerLikeTypeTraits<T*>::NumLowBitsAvailable;
+    return reinterpret_cast<T*>(Val);
+  }
+  static inline T* getTombstoneKey() {
+    intptr_t Val = -2;
+    Val <<= PointerLikeTypeTraits<T*>::NumLowBitsAvailable;
+    return reinterpret_cast<T*>(Val);
+  }
   static unsigned getHashValue(const T *PtrVal) {
     return (unsigned((uintptr_t)PtrVal) >> 4) ^
            (unsigned((uintptr_t)PtrVal) >> 9);
diff --git a/include/llvm/ADT/PointerIntPair.h b/include/llvm/ADT/PointerIntPair.h
index f189a328582..51a0c77fdca 100644
--- a/include/llvm/ADT/PointerIntPair.h
+++ b/include/llvm/ADT/PointerIntPair.h
@@ -107,11 +107,14 @@ template<typename PointerTy, unsigned IntBits, typename IntType>
 struct DenseMapInfo<PointerIntPair<PointerTy, IntBits, IntType> > {
   typedef PointerIntPair<PointerTy, IntBits, IntType> Ty;
   static Ty getEmptyKey() {
-    return Ty(reinterpret_cast<PointerTy>(-1 << IntBits),
-              IntType((1 << IntBits)-1));
+    intptr_t Val = -1;
+    Val <<= PointerLikeTypeTraits<PointerTy>::NumLowBitsAvailable;
+    return Ty(reinterpret_cast<PointerTy>(Val), IntType((1 << IntBits)-1));
   }
   static Ty getTombstoneKey() {
-    return Ty(reinterpret_cast<PointerTy>(-2 << IntBits), IntType(0));
+    intptr_t Val = -2;
+    Val <<= PointerLikeTypeTraits<PointerTy>::NumLowBitsAvailable;
+    return Ty(reinterpret_cast<PointerTy>(Val), IntType(0));
   }
   static unsigned getHashValue(Ty V) {
     uintptr_t IV = reinterpret_cast<uintptr_t>(V.getOpaqueValue());
-- 
2.34.1