// Use is here to make keeping the "use" list of a Value up-to-date really easy.
//
class Use {
- class UseWaymark;
- friend class UseWaymark;
- Value *getValue() const;
- /// nilUse - returns a 'token' that marks the end of the def/use chain
- static Use *nilUse(const Value *V) {
- return addTag((Use*)V, fullStopTagN);
- }
- static bool isNil(Use *U) { return extractTag<NextPtrTag, tagMaskN>(U) == fullStopTagN; }
- void showWaymarks() const;
- static bool isStop(Use *U) {
- return isStopTag(extractTag<NextPtrTag, tagMaskN>(U));
- }
-public:
+private:
/// init - specify Value and User
/// @deprecated in 2.4, will be removed soon
inline void init(Value *V, User *U);
+public:
/// swap - provide a fast substitute to std::swap<Use>
/// that also works with less standard-compliant compilers
void swap(Use &RHS);
/// Destructor - Only for zap()
inline ~Use() {
- if (Val1) removeFromList();
+ if (Val) removeFromList();
}
/// Default ctor - This leaves the Use completely uninitialized. The only thing
enum PrevPtrTag { zeroDigitTag = noTag
, oneDigitTag = tagOne
, stopTag = tagTwo
- , fullStopTag = tagThree
- , tagMask = tagThree };
-
- enum NextPtrTag { zeroDigitTagN = tagTwo
- , oneDigitTagN = tagOne
- , stopTagN = noTag
- , fullStopTagN = tagThree
- , tagMaskN = tagThree };
-
- static bool isStopTag(NextPtrTag T) {
- bool P[] = { true, false, false, true };
- return P[T];
- }
+ , fullStopTag = tagThree };
+
public:
- operator Value*() const { return get(); }
- inline Value *get() const;
+ operator Value*() const { return Val; }
+ Value *get() const { return Val; }
User *getUser() const;
const Use* getImpliedUser() const;
static Use *initTags(Use *Start, Use *Stop, ptrdiff_t Done = 0);
return RHS;
}
const Use &operator=(const Use &RHS) {
- set(RHS.Val1);
+ set(RHS.Val);
return *this;
}
- Value *operator->() { return get(); }
- const Value *operator->() const { return get(); }
+ Value *operator->() { return Val; }
+ const Value *operator->() const { return Val; }
- Use *getNext() const { return extractTag<NextPtrTag, tagMaskN>(Next) == fullStopTagN
- ? 0
- : stripTag<tagMaskN>(Next); }
+ Use *getNext() const { return Next; }
private:
- Value *Val1;
+ Value *Val;
Use *Next, **Prev;
void setPrev(Use **NewPrev) {
- Prev = transferTag<tagMask>(Prev, NewPrev);
+ Prev = transferTag<fullStopTag>(Prev, NewPrev);
}
void addToList(Use **List) {
Next = *List;
- Use *StrippedNext(getNext());
- if (StrippedNext) StrippedNext->setPrev(&Next);
+ if (Next) Next->setPrev(&Next);
setPrev(List);
*List = this;
}
void removeFromList() {
- // __builtin_prefetch(Next);
- Use **StrippedPrev = stripTag<tagMask>(Prev);
- Use *StrippedNext(getNext());
- if (isStop(Next))
- assert((isStop(*StrippedPrev) || (StrippedNext ? isStop(StrippedNext->Next) : true)) && "joining digits?");
+ Use **StrippedPrev = stripTag<fullStopTag>(Prev);
*StrippedPrev = Next;
- if (StrippedNext) StrippedNext->setPrev(StrippedPrev);
+ if (Next) Next->setPrev(StrippedPrev);
}
friend class Value;
typedef value_use_iterator<UserTy> _Self;
Use *U;
- explicit value_use_iterator(Use *u) : U(extractTag<Use::NextPtrTag, Use::tagMaskN>(u)
- == Use::fullStopTagN
- ? 0
- : stripTag<Use::tagMaskN>(u)) {}
+ explicit value_use_iterator(Use *u) : U(u) {}
friend class Value;
public:
typedef typename super::reference reference;
}
/// atEnd - return true if this iterator is equal to use_end() on the value.
- bool atEnd() const { return !U; }
+ bool atEnd() const { return U == 0; }
// Iterator traversal: forward iteration only
_Self &operator++() { // Preincrement
- assert(!atEnd() && "Cannot increment end iterator!");
+ assert(U && "Cannot increment end iterator!");
U = U->getNext();
return *this;
}
_Self tmp = *this; ++*this; return tmp;
}
- // Retrieve a reference to the current User
+ // Retrieve a pointer to the current User.
UserTy *operator*() const {
- assert(!atEnd() && "Cannot dereference end iterator!");
+ assert(U && "Cannot dereference end iterator!");
return U->getUser();
}
unsigned getOperandNo() const;
};
-Value *Use::get() const {
- return fullStopTagN == extractTag<NextPtrTag, tagMaskN>(Next)
- ? reinterpret_cast<Value*>(stripTag<tagMaskN>(Next))
- : (Val1 == getValue() ? Val1 : 0); // should crash if not equal!
-}
template<> struct simplify_type<value_use_iterator<User> > {
typedef User* SimpleType;
+++ /dev/null
-//===-- 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
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