//
//===----------------------------------------------------------------------===//
//
-// This header defines the interface to the LLVM difference engine,
-// which structurally compares functions within a module.
+// This header defines the implementation of the LLVM difference
+// engine, which structurally compares global values within a module.
//
//===----------------------------------------------------------------------===//
-#include <utility>
-
-#include <llvm/ADT/DenseMap.h>
-#include <llvm/ADT/DenseSet.h>
-#include <llvm/ADT/SmallVector.h>
-#include <llvm/ADT/StringRef.h>
-#include <llvm/ADT/StringSet.h>
-
-#include <llvm/Module.h>
-#include <llvm/Function.h>
-#include <llvm/Instructions.h>
-#include <llvm/Support/CFG.h>
+#include "DifferenceEngine.h"
-#include <llvm/Support/raw_ostream.h>
-#include <llvm/Support/type_traits.h>
-#include <llvm/Support/ErrorHandling.h>
-#include <llvm/Support/CallSite.h>
+#include "llvm/Constants.h"
+#include "llvm/Function.h"
+#include "llvm/Instructions.h"
+#include "llvm/Module.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/Support/CallSite.h"
+#include "llvm/Support/CFG.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/type_traits.h"
-#include "DifferenceEngine.h"
+#include <utility>
using namespace llvm;
Queue.insert(BlockPair(L, R));
return false;
}
+
+ /// Unifies two instructions, given that they're known not to have
+ /// structural differences.
+ void unify(Instruction *L, Instruction *R) {
+ DifferenceEngine::Context C(Engine, L, R);
+
+ bool Result = diff(L, R, true, true);
+ assert(!Result && "structural differences second time around?");
+ (void) Result;
+ if (!L->use_empty())
+ Values[L] = R;
+ }
void processQueue() {
while (!Queue.empty()) {
DifferenceEngine::Context C(Engine, L, R);
BasicBlock::iterator LI = L->begin(), LE = L->end();
- BasicBlock::iterator RI = R->begin(), RE = R->end();
+ BasicBlock::iterator RI = R->begin();
llvm::SmallVector<std::pair<Instruction*,Instruction*>, 20> TentativePairs;
do {
- assert(LI != LE && RI != RE);
+ assert(LI != LE && RI != R->end());
Instruction *LeftI = &*LI, *RightI = &*RI;
// If the instructions differ, start the more sophisticated diff
} while (LI != LE); // This is sufficient: we can't get equality of
// terminators if there are residual instructions.
+ // Unify everything in the block, non-tentatively this time.
TentativeValues.clear();
-
- // Do another pass over the block, this time in complaints mode.
- LI = L->begin(); RI = R->begin();
- do {
- assert(LI != LE && RI != RE);
- bool Result = diff(&*LI, &*RI, true, true);
- assert(!Result && "structural differences second time around?");
- (void) Result;
-
- // Make the mapping non-tentative this time.
- if (!LI->use_empty())
- Values[&*LI] = &*RI;
-
- ++LI, ++RI;
- } while (LI != LE);
+ for (LI = L->begin(), RI = R->begin(); LI != LE; ++LI, ++RI)
+ unify(&*LI, &*RI);
}
bool matchForBlockDiff(Instruction *L, Instruction *R);
} else if (isa<PHINode>(L)) {
// FIXME: implement.
- // This is really wierd; type uniquing is broken?
+ // This is really weird; type uniquing is broken?
if (L->getType() != R->getType()) {
if (!L->getType()->isPointerTy() || !R->getType()->isPointerTy()) {
if (Complain) Engine.log("different phi types");
bool Difference = false;
- DenseMap<ConstantInt*,BasicBlock*> LCases;
- for (unsigned I = 1, E = LI->getNumCases(); I != E; ++I)
- LCases[LI->getCaseValue(I)] = LI->getSuccessor(I);
- for (unsigned I = 1, E = RI->getNumCases(); I != E; ++I) {
- ConstantInt *CaseValue = RI->getCaseValue(I);
+ DenseMap<Constant*, BasicBlock*> LCases;
+
+ for (SwitchInst::CaseIt I = LI->case_begin(), E = LI->case_end();
+ I != E; ++I)
+ LCases[I.getCaseValueEx()] = I.getCaseSuccessor();
+
+ for (SwitchInst::CaseIt I = RI->case_begin(), E = RI->case_end();
+ I != E; ++I) {
+ IntegersSubset CaseValue = I.getCaseValueEx();
BasicBlock *LCase = LCases[CaseValue];
if (LCase) {
- if (TryUnify) tryUnify(LCase, RI->getSuccessor(I));
+ if (TryUnify) tryUnify(LCase, I.getCaseSuccessor());
LCases.erase(CaseValue);
- } else if (!Difference) {
+ } else if (Complain || !Difference) {
if (Complain)
Engine.logf("right switch has extra case %r") << CaseValue;
Difference = true;
}
}
if (!Difference)
- for (DenseMap<ConstantInt*,BasicBlock*>::iterator
+ for (DenseMap<Constant*, BasicBlock*>::iterator
I = LCases.begin(), E = LCases.end(); I != E; ++I) {
if (Complain)
Engine.logf("left switch has extra case %l") << I->first;
for (unsigned I = 0; I != NL+1; ++I) {
Cur[I].Cost = I * LeftCost;
for (unsigned J = 0; J != I; ++J)
- Cur[I].Path.push_back(DifferenceEngine::DC_left);
+ Cur[I].Path.push_back(DC_left);
}
for (BasicBlock::iterator RI = RStart; RI != RE; ++RI) {
// Initialize the first row.
Next[0] = Cur[0];
Next[0].Cost += RightCost;
- Next[0].Path.push_back(DifferenceEngine::DC_right);
+ Next[0].Path.push_back(DC_right);
unsigned Index = 1;
for (BasicBlock::iterator LI = LStart; LI != LE; ++LI, ++Index) {
if (matchForBlockDiff(&*LI, &*RI)) {
Next[Index] = Cur[Index-1];
Next[Index].Cost += MatchCost;
- Next[Index].Path.push_back(DifferenceEngine::DC_match);
+ Next[Index].Path.push_back(DC_match);
TentativeValues.insert(std::make_pair(&*LI, &*RI));
} else if (Next[Index-1].Cost <= Cur[Index].Cost) {
Next[Index] = Next[Index-1];
Next[Index].Cost += LeftCost;
- Next[Index].Path.push_back(DifferenceEngine::DC_left);
+ Next[Index].Path.push_back(DC_left);
} else {
Next[Index] = Cur[Index];
Next[Index].Cost += RightCost;
- Next[Index].Path.push_back(DifferenceEngine::DC_right);
+ Next[Index].Path.push_back(DC_right);
}
}
std::swap(Cur, Next);
}
+ // We don't need the tentative values anymore; everything from here
+ // on out should be non-tentative.
+ TentativeValues.clear();
+
SmallVectorImpl<char> &Path = Cur[NL].Path;
BasicBlock::iterator LI = LStart, RI = RStart;
- DifferenceEngine::DiffLogBuilder Diff(Engine);
+ DiffLogBuilder Diff(Engine.getConsumer());
// Drop trailing matches.
- while (Path.back() == DifferenceEngine::DC_match)
+ while (Path.back() == DC_match)
Path.pop_back();
// Skip leading matches.
SmallVectorImpl<char>::iterator
PI = Path.begin(), PE = Path.end();
- while (PI != PE && *PI == DifferenceEngine::DC_match)
+ while (PI != PE && *PI == DC_match) {
+ unify(&*LI, &*RI);
++PI, ++LI, ++RI;
+ }
for (; PI != PE; ++PI) {
- switch (static_cast<DifferenceEngine::DiffChange>(*PI)) {
- case DifferenceEngine::DC_match:
+ switch (static_cast<DiffChange>(*PI)) {
+ case DC_match:
assert(LI != LE && RI != RE);
{
Instruction *L = &*LI, *R = &*RI;
- DifferenceEngine::Context C(Engine, L, R);
- diff(L, R, true, true); // complain and unify successors
- Values[L] = R; // make non-tentative
+ unify(L, R);
Diff.addMatch(L, R);
}
++LI; ++RI;
break;
- case DifferenceEngine::DC_left:
+ case DC_left:
assert(LI != LE);
Diff.addLeft(&*LI);
++LI;
break;
- case DifferenceEngine::DC_right:
+ case DC_right:
assert(RI != RE);
Diff.addRight(&*RI);
++RI;
}
}
- TentativeValues.clear();
+ // Finishing unifying and complaining about the tails of the block,
+ // which should be matches all the way through.
+ while (LI != LE) {
+ assert(RI != RE);
+ unify(&*LI, &*RI);
+ ++LI, ++RI;
+ }
+
+ // If the terminators have different kinds, but one is an invoke and the
+ // other is an unconditional branch immediately following a call, unify
+ // the results and the destinations.
+ TerminatorInst *LTerm = LStart->getParent()->getTerminator();
+ TerminatorInst *RTerm = RStart->getParent()->getTerminator();
+ if (isa<BranchInst>(LTerm) && isa<InvokeInst>(RTerm)) {
+ if (cast<BranchInst>(LTerm)->isConditional()) return;
+ BasicBlock::iterator I = LTerm;
+ if (I == LStart->getParent()->begin()) return;
+ --I;
+ if (!isa<CallInst>(*I)) return;
+ CallInst *LCall = cast<CallInst>(&*I);
+ InvokeInst *RInvoke = cast<InvokeInst>(RTerm);
+ if (!equivalentAsOperands(LCall->getCalledValue(), RInvoke->getCalledValue()))
+ return;
+ if (!LCall->use_empty())
+ Values[LCall] = RInvoke;
+ tryUnify(LTerm->getSuccessor(0), RInvoke->getNormalDest());
+ } else if (isa<InvokeInst>(LTerm) && isa<BranchInst>(RTerm)) {
+ if (cast<BranchInst>(RTerm)->isConditional()) return;
+ BasicBlock::iterator I = RTerm;
+ if (I == RStart->getParent()->begin()) return;
+ --I;
+ if (!isa<CallInst>(*I)) return;
+ CallInst *RCall = cast<CallInst>(I);
+ InvokeInst *LInvoke = cast<InvokeInst>(LTerm);
+ if (!equivalentAsOperands(LInvoke->getCalledValue(), RCall->getCalledValue()))
+ return;
+ if (!LInvoke->use_empty())
+ Values[LInvoke] = RCall;
+ tryUnify(LInvoke->getNormalDest(), RTerm->getSuccessor(0));
+ }
}
}
+void DifferenceEngine::Oracle::anchor() { }
+
void DifferenceEngine::diff(Function *L, Function *R) {
Context C(*this, L, R);
projects / oota-llvm.git / blobdiff