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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56349 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 11 insertions, 510 deletions

diff --git a/lib/VMCore/Use.cpp b/lib/VMCore/Use.cpp
index 3cdf347427..d96a0e57fd 100644
--- a/lib/VMCore/Use.cpp
+++ b/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;
diff --git a/lib/VMCore/Value.cpp b/lib/VMCore/Value.cpp
index a5e0ff397e..bc5b7a9f81 100644
--- a/lib/VMCore/Value.cpp
+++ b/lib/VMCore/Value.cpp
@@ -34,7 +34,7 @@ static inline const Type *checkType(const Type *Ty) {
 
 Value::Value(const Type *ty, unsigned scid)
   : SubclassID(scid), SubclassData(0), VTy(checkType(ty)),
-    UseList(Use::nilUse(this)), Name(0) {
+    UseList(0), Name(0) {
   if (isa<CallInst>(this) || isa<InvokeInst>(this))
     assert((VTy->isFirstClassType() || VTy == Type::VoidTy ||
             isa<OpaqueType>(ty) || VTy->getTypeID() == Type::StructTyID) &&
@@ -298,7 +298,7 @@ void Value::takeName(Value *V) {
 //
 void Value::uncheckedReplaceAllUsesWith(Value *New) {
   while (!use_empty()) {
-    Use &U = *use_begin().U;
+    Use &U = *UseList;
     // Must handle Constants specially, we cannot call replaceUsesOfWith on a
     // constant because they are uniqued.
     if (Constant *C = dyn_cast<Constant>(U.getUser())) {
diff --git a/lib/VMCore/getValue.cpp b/lib/VMCore/getValue.cpp
deleted file mode 100644
index 2eae584402..0000000000
--- a/lib/VMCore/getValue.cpp
+++ /dev/null
@@ -1,474 +0,0 @@
-//===-- Use.cpp - Implement the Use class ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the algorithm for finding the User of a Use.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/User.h"
-// this can later be removed:
-#include <iostream>
-
-namespace llvm {
-
-class Use::UseWaymark {
-
-  friend class Use;
-
-enum { spareBits = 2, requiredSteps = sizeof(Value*) * 8 - spareBits };
-
-/// repaintByCopying -- given a pattern and a
-/// junk tagspace, copy the former's tags into
-/// the latter
-///
-static inline void repaintByCopying(Use *Tagspace, Use *Junk) {
-    for (int I = requiredSteps; I; --I) {
-        Use *Next = stripTag<Use::tagMaskN>(Junk->Next);
-        Junk->Next = transferTag<Use::tagMaskN>(Tagspace->Next, Next);
-        Tagspace = stripTag<Use::tagMaskN>(Tagspace->Next);
-        Junk = Next;
-    }
-
-    assert((extractTag<Use::NextPtrTag, Use::tagMaskN>(Junk->Next) == Use::stopTagN)
-           && "Why repaint by copying if the next is not Stop?");
-}
-
-
-/// repaintByCalculating -- given a pattern and a
-/// junk tagspace, compute tags into the latter
-///
-static inline void repaintByCalculating(unsigned long Tags, Use *Junk) {
-    Tags >>= spareBits;
-
-    for (int I = requiredSteps - 1; I >= 0; --I) {
-        Use::NextPtrTag Tag(Tags & (1 << I) ? Use::oneDigitTagN : Use::zeroDigitTagN);
-        Use *Next = stripTag<Use::tagMaskN>(Junk->Next);
-        Junk->Next = transferTag<Use::tagMaskN>(reinterpret_cast<Use*>(Tag), Next);
-        Junk = Next;
-    }
-
-    assert((extractTag<Use::NextPtrTag, Use::tagMaskN>(Junk->Next) == Use::fullStopTagN)
-           && "Why repaint by calculating if the next is not FullStop?");
-}
-
-/// punchAwayDigits -- ensure that repainted area
-/// begins with a stop
-///
-static inline void punchAwayDigits(Use **Uprev) {
-  Uprev = stripTag<Use::tagMask>(Uprev);
-  // if (PrevU)
-  //   assert(&PrevU->Next == Uprev && "U->Prev differs from PrevU?");
-  *Uprev = stripTag<Use::tagMaskN>(*Uprev);
-}
-
-
-/// gatherAndPotentiallyRepaint is invoked for either
-///  - sweeping over (a small amount of) initial junk
-///  - or sweeping over a great amount of junk which
-///    provides enough space to reproduce the bit pattern
-///    of the Value* at its end, in which case it gets
-///    overpainted.
-///  In any case this routine is invoked with U being
-///  pointed at from a Use with a stop tag.
-///
-static inline Value *gatherAndPotentiallyRepaint(Use *U) {
-  int Cushion = requiredSteps;
-
-  Use *Next(U->Next);
-  // __builtin_prefetch(Next);
-  Use::NextPtrTag Tag(extractTag<Use::NextPtrTag, Use::tagMaskN>(Next));
-  Next = stripTag<Use::tagMaskN>(Next);
-
-  // try to pick up exactly requiredSteps digits
-  // from immediately behind the (precondition) stop
-  unsigned long Acc(0);
-  while (1) {
-      if (Cushion <= 0) {
-          assert((Tag == Use::fullStopTagN || Tag == Use::stopTagN)
-                 && "More digits?");
-          return reinterpret_cast<Value*>(Acc << spareBits);
-      }
-
-      switch (Tag) {
-          case Use::fullStopTagN:
-              return reinterpret_cast<Value*>(Next);
-          case Use::stopTagN: {
-	      goto efficiency;
-          }
-          default:
-              Acc = (Acc << 1) | (Tag & 1);
-              Next = Next->Next;
-              // __builtin_prefetch(Next);
-              --Cushion;
-              Tag = extractTag<Use::NextPtrTag, Use::tagMaskN>(Next);
-              Next = stripTag<Use::tagMaskN>(Next);
-              continue;
-      }
-      break;
-  }
-
-  while (Cushion > 0) {
-    switch (Tag) {
-    case Use::fullStopTagN:
-        return reinterpret_cast<Value*>(Next);
-    case Use::stopTagN: {
-        efficiency:
-        // try to pick up exactly requiredSteps digits
-        int digits = requiredSteps;
-        Acc = 0;
-
-        while (1) {
-            if (!digits)
-                return reinterpret_cast<Value*>(Acc << spareBits);
-
-            Next = Next->Next;
-            // __builtin_prefetch(Next);
-            --Cushion;
-            Tag = extractTag<Use::NextPtrTag, Use::tagMaskN>(Next);
-            Next = stripTag<Use::tagMaskN>(Next);
-            switch (Tag) {
-                case Use::fullStopTagN:
-                    if (Cushion <= 0) {
-                        punchAwayDigits(U->Prev);
-                        repaintByCalculating(reinterpret_cast<unsigned long>(Next), U);
-                    }
-                    return reinterpret_cast<Value*>(Next);
-                case Use::stopTagN: {
-                    if (Cushion <= 0) {
-                        U = stripTag<Use::tagMaskN>(U->Next);
-                    }
-                    goto efficiency;
-                }
-                default:
-                    --digits;
-                    Acc = (Acc << 1) | (Tag & 1);
-                    if (Cushion <= 0) {
-                        U = stripTag<Use::tagMaskN>(U->Next);
-                    }
-                    continue;
-            }
-            break;
-        }
-    }
-    // fall through
-    default:
-        Next = Next->Next;
-        // __builtin_prefetch(Next);
-        --Cushion;
-        Tag = extractTag<Use::NextPtrTag, Use::tagMaskN>(Next);
-        Next = stripTag<Use::tagMaskN>(Next);
-    } // switch
-  } // while
-
-  // Now we know that we have a nice cushion between U and Next. Do the same
-  // thing as above, but don't decrement Cushion any more, instead push U
-  // forward. After the value is found, repaint beginning at U.
-
-  while (1) {
-    switch (Tag) {
-    case Use::fullStopTagN: {
-        punchAwayDigits(U->Prev);
-        repaintByCalculating(reinterpret_cast<unsigned long>(Next), U);
-        return reinterpret_cast<Value*>(Next);
-    }
-    case Use::stopTagN: {
-        // try to pick up exactly requiredSteps digits
-        int digits = requiredSteps;
-        Acc = 0;
-        Use *Tagspace(Next);
-
-        while (1) {
-            if (!digits) {
-                punchAwayDigits(U->Prev);
-                repaintByCopying(Tagspace, U);
-                return reinterpret_cast<Value*>(Acc << spareBits);
-            }
-
-            Next = Next->Next;
-            // __builtin_prefetch(Next);
-            U = stripTag<Use::tagMaskN>(U->Next);
-            Tag = extractTag<Use::NextPtrTag, Use::tagMaskN>(Next);
-            Next = stripTag<Use::tagMaskN>(Next);
-            switch (Tag) {
-                case Use::fullStopTagN: {
-                    punchAwayDigits(U->Prev);
-                    repaintByCalculating(reinterpret_cast<unsigned long>(Next), U);
-                    return reinterpret_cast<Value*>(Next);
-                }
-                case Use::stopTagN: {
-                    break;
-                }
-                default:
-                    --digits;
-                    Acc = (Acc << 1) | (Tag & 1);
-                    continue;
-            }
-            break;
-        }
-    }
-    // fall through
-    default:
-        Next = Next->Next;
-        // __builtin_prefetch(Next);
-        U = stripTag<Use::tagMaskN>(U->Next);
-        Tag = extractTag<Use::NextPtrTag, Use::tagMaskN>(Next);
-        Next = stripTag<Use::tagMaskN>(Next);
-    } // switch
-  } // while
-}
-
-
-/// skipPotentiallyGathering is invoked for either
-///  - picking up exactly ToGo digits
-///  - or finding a stop which marks the beginning
-///    of a repaintable area
-///
-static inline Value *skipPotentiallyGathering(Use *U,
-                                              unsigned long Acc,
-                                              int ToGo) {
-  while (1) {
-    if (!ToGo)
-      return reinterpret_cast<Value*>(Acc << spareBits);
-
-    Use *Next(U->Next);
-    // __builtin_prefetch(Next);
-    Use::NextPtrTag Tag(extractTag<Use::NextPtrTag, Use::tagMaskN>(Next));
-    Next = stripTag<Use::tagMaskN>(Next);
-    switch (Tag) {
-    case Use::fullStopTagN:
-      return reinterpret_cast<Value*>(Next);
-    case Use::stopTagN:
-      return gatherAndPotentiallyRepaint(Next);
-    default:
-      Acc = (Acc << 1) | (Tag & 1);
-      --ToGo;
-      U = Next;
-    }
-  }
-}
-
-}; // class UseWaymark
-
-Value *Use::getValue() const {
-  // __builtin_prefetch(Next);
-  NextPtrTag Tag(extractTag<NextPtrTag, tagMaskN>(Next));
-  switch (Tag) {
-  case fullStopTagN:
-      return reinterpret_cast<Value*>(stripTag<tagMaskN>(Next));
-  case stopTagN:
-    return UseWaymark::gatherAndPotentiallyRepaint(Next);
-  default:
-    return UseWaymark::skipPotentiallyGathering(stripTag<tagMaskN>(Next),
-                                    Tag & 1,
-                                    Use::UseWaymark::requiredSteps - 1);
-  }
-}
-
-static char TagChar(int Tag) {
-  return "s10S"[Tag];
-}
-
-void Use::showWaymarks() const {
-  const Use *me(this);
-  if (NextPtrTag Tag = extractTag<Use::NextPtrTag, Use::tagMaskN>(me)) {
-    me = stripTag<tagMaskN>(me);
-    std::cerr << '(' << TagChar(Tag) << ')';
-  }
-
-  me = me->Next;
-  NextPtrTag TagHere = extractTag<Use::NextPtrTag, Use::tagMaskN>(me);
-  std::cerr << TagChar(TagHere);
-
-  me = stripTag<tagMaskN>(me);
-  if (TagHere == fullStopTagN) {
-    std::cerr << " ---> " << me << std::endl;
-    std::cerr << "1234567890123456789012345678901234567890123456789012345678901234567890" << std::endl;
-    std::cerr << "         1         2         3         4         5         6         7" << std::endl;
-  }
-  else
-    me->showWaymarks();
-}
-
-} // namespace llvm
-
-#if 0
-
-// ################################################################
-// ############################# TESTS ############################
-// ################################################################
-
-using namespace llvm;
-
-namespace T1
-{
-    Use u00;
-}
-
-namespace T2
-{
-    Use u00((Value*)0xCAFEBABCUL);
-    Use u01(u00);
-}
-
-namespace T3
-{
-    template <unsigned NEST>
-    struct UseChain;
-
-    template <>
-    struct UseChain<0> {
-        Use first;
-        UseChain(Value *V) : first(V) {}
-        UseChain(Use &U) : first(U) {}
-    };
-
-    template <unsigned NEST>
-    struct UseChain {
-        Use first;
-        UseChain<NEST - 1> rest;
-        UseChain(Value *V)
-            : first(rest.first)
-            , rest(V) {}
-        UseChain(Use &U)
-            : first(rest.first)
-            , rest(U) {}
-    };
-
-    UseChain<30> uc31((Value*)0xCAFEBABCUL);
-    Use& u31(uc31.first);
-    UseChain<31> uc32((Value*)0xCAFEBABCUL);
-    Use& u32(uc32.first);
-}
-
-namespace T4
-{
-    template <unsigned NEST, unsigned long PAT>
-    struct UseChain;
-
-    template <unsigned long PAT>
-    struct UseChain<0, PAT> {
-        Use first;
-        static const unsigned long Pat = PAT >> 2;
-        UseChain(Value *V) : first(V) {}
-        UseChain(Use &U) : first(U) {}
-    };
-
-    template <unsigned NEST, unsigned long PAT>
-    struct UseChain {
-        Use first;
-        UseChain<NEST - 1, PAT> rest;
-        static const unsigned long Digit = UseChain<NEST - 1, PAT>::Pat & 1;
-        static const Use::NextPtrTag Tag = Digit ? Use::oneDigitTagN : Use::zeroDigitTagN;
-        static const unsigned long Pat = UseChain<NEST - 1, PAT>::Pat >> 1;
-        UseChain(Value *V = reinterpret_cast<Value*>(PAT))
-            : first(*addTag(&rest.first, Tag))
-            , rest(V) {}
-        UseChain(Use &U)
-            : first(*addTag(&rest.first, Tag))
-            , rest(U) {}
-    };
-
-    UseChain<30, 0xCAFEBABCUL> uc31;
-    Use& u31(uc31.first);
-    Use us32(u31);
-
-    UseChain<29, 0xCAFEBABCUL> uc30;
-    Use& u30(uc30.first);
-    Use us31(u30);
-
-    T3::UseChain<3> s3a((Value*)0xCAFEBABCUL);
-    UseChain<30, 0xCAFEBABCUL> uc31s3S(s3a.first);
-    Use& m35(uc31s3S.first);
-
-    T3::UseChain<3> s3b((Value*)0xCAFEBABCUL);
-    UseChain<29, 0xCAFEBABCUL> uc30s3S(s3b.first);
-    Use& m34(uc30s3S.first);
-    
-    T3::UseChain<3> s3c((Value*)0xCAFEBABCUL);
-    UseChain<25, 0xCAFEBABCUL> uc25s3S(s3c.first);
-    Use& m30(uc25s3S.first);
-
-    Use ms36(m35);
-    Use ms35(m34);
-    Use ms31(m30);
-    Use ms32(ms31);
-
-    UseChain<24, 0xCAFEBABCUL> uc25;
-    Use& u25(uc25.first);
-    T3::UseChain<10> m11s24dS(u25);
-    Use& m36(m11s24dS.first);
-
-
-    T3::UseChain<10> s10S((Value*)0xCAFEBABCUL);
-    UseChain<20, 0xCAFEBABCUL> d20ss10S(s10S.first);
-    T3::UseChain<20> s20sd20ss10S(d20ss10S.first);
-    Use& m53(s20sd20ss10S.first);
-}
-
-
-int main(){
-    if (NULL != T1::u00.getValue())
-        return 1;
-    if ((Value*)0xCAFEBABCUL != T2::u00.getValue())
-        return 2;
-    if ((Value*)0xCAFEBABCUL != T2::u01.getValue())
-        return 2;
-    if ((Value*)0xCAFEBABCUL != T3::u31.getValue())
-        return 3;
-    if ((Value*)0xCAFEBABCUL != T3::u32.getValue())
-        return 3;
-    if ((Value*)0xCAFEBABCUL != T3::u32.getValue()) // check the mutated value
-        return 3;
-    if ((Value*)0xCAFEBABCUL != T4::u31.getValue())
-        return 4;
-    if ((Value*)0xCAFEBABCUL != T4::u30.getValue())
-        return 4;
-    if ((Value*)0xCAFEBABCUL != T4::us32.getValue())
-        return 4;
-    if ((Value*)0xCAFEBABCUL != T4::us31.getValue())
-        return 4;
-
-    // mixed tests
-    if ((Value*)0xCAFEBABCUL != T4::m35.getValue())
-        return 4;
-    if ((Value*)0xCAFEBABCUL != T4::m34.getValue())
-        return 4;
-    if ((Value*)0xCAFEBABCUL != T4::m30.getValue())
-        return 4;
-    if ((Value*)0xCAFEBABCUL != T4::ms36.getValue())
-        return 4;
-    if ((Value*)0xCAFEBABCUL != T4::ms35.getValue())
-        return 4;
-    if ((Value*)0xCAFEBABCUL != T4::ms35.getValue()) // check the mutated value
-        return 4;
-    if ((Value*)0xCAFEBABCUL != T4::ms32.getValue())
-        return 4;
-    if ((Value*)0xCAFEBABCUL != T4::ms32.getValue())
-        return 4;
-    if ((Value*)0xCAFEBABCUL != T4::ms32.getValue()) // check the mutated value
-        return 4;
-
-    T4::m36.showWaymarks();
-    if ((Value*)0xCAFEBABCUL != T4::m36.getValue())
-        return 4;
-    T4::m36.showWaymarks();
-    if ((Value*)0xCAFEBABCUL != T4::m36.getValue()) // check the mutated value
-        return 4;
-    T4::m36.showWaymarks();
-
-    T4::m53.showWaymarks();
-    if ((Value*)0xCAFEBABCUL != T4::m53.getValue())
-        return 4;
-    T4::m53.showWaymarks();
-    if ((Value*)0xCAFEBABCUL != T4::m53.getValue()) // check the mutated value
-        return 4;
-    T4::m53.showWaymarks();
-}
-
-#endif