backing out my last commit, it was not intended to go on the trunk

llvm-svn: 56349

1 files changed, 9 insertions, 34 deletions

diff --git a/llvm/lib/VMCore/Use.cpp b/llvm/lib/VMCore/Use.cpp
index 3cdf3474270..d96a0e57fd4 100644
--- a/llvm/lib/VMCore/Use.cpp
+++ b/llvm/lib/VMCore/Use.cpp
@@ -20,31 +20,8 @@ namespace llvm {
 //===----------------------------------------------------------------------===//
 
 void Use::swap(Use &RHS) {
-  ptrdiff_t dist((char*)&RHS - (char*)this);
-
-  if (dist) {
-    Use *valid1(stripTag<tagMaskN>(Next));
-    Use *valid2(stripTag<tagMaskN>(RHS.Next));
-    if (valid1 && valid2) {
-      bool real1(fullStopTagN != extractTag<NextPtrTag, tagMaskN>(Next));
-      bool real2(fullStopTagN != extractTag<NextPtrTag, tagMaskN>(RHS.Next));
-      (char*&)*stripTag<tagMask>(Prev) += dist;
-      (char*&)*stripTag<tagMask>(RHS.Prev) -= dist;
-      if (real1)
-	(char*&)valid1->Next += dist;
-      if (real2)
-        (char*&)valid2->Next -= dist;
-
-    }
-
-    // swap the members
-    std::swap(Next, RHS.Next);
-    Use** Prev1 = transferTag<tagMask>(Prev, stripTag<tagMask>(RHS.Prev));
-    RHS.Prev = transferTag<tagMask>(RHS.Prev, stripTag<tagMask>(Prev));
-    Prev = Prev1;
-  }
-  /*  Value *V1(Val1);
-  Value *V2(RHS.Val1);
+  Value *V1(Val);
+  Value *V2(RHS.Val);
   if (V1 != V2) {
     if (V1) {
       removeFromList();
@@ -52,20 +29,19 @@ void Use::swap(Use &RHS) {
 
     if (V2) {
       RHS.removeFromList();
-      Val1 = V2;
+      Val = V2;
       V2->addUse(*this);
     } else {
-      Val1 = 0;
+      Val = 0;
     }
 
     if (V1) {
-      RHS.Val1 = V1;
+      RHS.Val = V1;
       V1->addUse(RHS);
     } else {
-      RHS.Val1 = 0;
+      RHS.Val = 0;
     }
   }
-  */
 }
 
 //===----------------------------------------------------------------------===//
@@ -76,7 +52,7 @@ const Use *Use::getImpliedUser() const {
   const Use *Current = this;
 
   while (true) {
-    unsigned Tag = extractTag<PrevPtrTag, tagMask>((Current++)->Prev);
+    unsigned Tag = extractTag<PrevPtrTag, fullStopTag>((Current++)->Prev);
     switch (Tag) {
       case zeroDigitTag:
       case oneDigitTag:
@@ -86,7 +62,7 @@ const Use *Use::getImpliedUser() const {
         ++Current;
         ptrdiff_t Offset = 1;
         while (true) {
-          unsigned Tag = extractTag<PrevPtrTag, tagMask>(Current->Prev);
+          unsigned Tag = extractTag<PrevPtrTag, fullStopTag>(Current->Prev);
           switch (Tag) {
             case zeroDigitTag:
             case oneDigitTag:
@@ -113,8 +89,7 @@ Use *Use::initTags(Use * const Start, Use *Stop, ptrdiff_t Done) {
   ptrdiff_t Count = Done;
   while (Start != Stop) {
     --Stop;
-    Stop->Val1 = 0;
-    Stop->Next = nilUse(0);
+    Stop->Val = 0;
     if (!Count) {
       Stop->Prev = reinterpret_cast<Use**>(Done == 0 ? fullStopTag : stopTag);
       ++Done;