Revert "IntRange:" as it appears to be breaking self hosting.
This reverts commit b2833d9dcba88c6f0520cad760619200adc0442c.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159618 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp
index 4a58eb3..f37ea91 100644
--- a/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -56,12 +56,26 @@
STATISTIC(NumSpeculations, "Number of speculative executed instructions");
namespace {
+ /// ValueEqualityComparisonCase - Represents a case of a switch.
+ struct ValueEqualityComparisonCase {
+ ConstantInt *Value;
+ BasicBlock *Dest;
+
+ ValueEqualityComparisonCase(ConstantInt *Value, BasicBlock *Dest)
+ : Value(Value), Dest(Dest) {}
+
+ bool operator<(ValueEqualityComparisonCase RHS) const {
+ // Comparing pointers is ok as we only rely on the order for uniquing.
+ return Value < RHS.Value;
+ }
+ };
+
class SimplifyCFGOpt {
const TargetData *const TD;
Value *isValueEqualityComparison(TerminatorInst *TI);
BasicBlock *GetValueEqualityComparisonCases(TerminatorInst *TI,
- IntegersSubsetToBB &Mapping);
+ std::vector<ValueEqualityComparisonCase> &Cases);
bool SimplifyEqualityComparisonWithOnlyPredecessor(TerminatorInst *TI,
BasicBlock *Pred,
IRBuilder<> &Builder);
@@ -518,25 +532,72 @@
/// decode all of the 'cases' that it represents and return the 'default' block.
BasicBlock *SimplifyCFGOpt::
GetValueEqualityComparisonCases(TerminatorInst *TI,
- IntegersSubsetToBB &Mapping) {
+ std::vector<ValueEqualityComparisonCase>
+ &Cases) {
if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
- for (SwitchInst::CaseIt i = SI->case_begin(), e = SI->case_end();
- i != e; ++i)
- Mapping.add(i.getCaseValueEx(), i.getCaseSuccessor());
+ Cases.reserve(SI->getNumCases());
+ for (SwitchInst::CaseIt i = SI->case_begin(), e = SI->case_end(); i != e; ++i)
+ Cases.push_back(ValueEqualityComparisonCase(i.getCaseValue(),
+ i.getCaseSuccessor()));
return SI->getDefaultDest();
}
-
+
BranchInst *BI = cast<BranchInst>(TI);
ICmpInst *ICI = cast<ICmpInst>(BI->getCondition());
- IntegersSubsetToBB Builder;
-
- Mapping.add(
- IntItem::fromConstantInt(GetConstantInt(ICI->getOperand(1), TD)),
- BI->getSuccessor(ICI->getPredicate() == ICmpInst::ICMP_NE));
-
+ BasicBlock *Succ = BI->getSuccessor(ICI->getPredicate() == ICmpInst::ICMP_NE);
+ Cases.push_back(ValueEqualityComparisonCase(GetConstantInt(ICI->getOperand(1),
+ TD),
+ Succ));
return BI->getSuccessor(ICI->getPredicate() == ICmpInst::ICMP_EQ);
}
+
+/// EliminateBlockCases - Given a vector of bb/value pairs, remove any entries
+/// in the list that match the specified block.
+static void EliminateBlockCases(BasicBlock *BB,
+ std::vector<ValueEqualityComparisonCase> &Cases) {
+ for (unsigned i = 0, e = Cases.size(); i != e; ++i)
+ if (Cases[i].Dest == BB) {
+ Cases.erase(Cases.begin()+i);
+ --i; --e;
+ }
+}
+
+/// ValuesOverlap - Return true if there are any keys in C1 that exist in C2 as
+/// well.
+static bool
+ValuesOverlap(std::vector<ValueEqualityComparisonCase> &C1,
+ std::vector<ValueEqualityComparisonCase > &C2) {
+ std::vector<ValueEqualityComparisonCase> *V1 = &C1, *V2 = &C2;
+
+ // Make V1 be smaller than V2.
+ if (V1->size() > V2->size())
+ std::swap(V1, V2);
+
+ if (V1->size() == 0) return false;
+ if (V1->size() == 1) {
+ // Just scan V2.
+ ConstantInt *TheVal = (*V1)[0].Value;
+ for (unsigned i = 0, e = V2->size(); i != e; ++i)
+ if (TheVal == (*V2)[i].Value)
+ return true;
+ }
+
+ // Otherwise, just sort both lists and compare element by element.
+ array_pod_sort(V1->begin(), V1->end());
+ array_pod_sort(V2->begin(), V2->end());
+ unsigned i1 = 0, i2 = 0, e1 = V1->size(), e2 = V2->size();
+ while (i1 != e1 && i2 != e2) {
+ if ((*V1)[i1].Value == (*V2)[i2].Value)
+ return true;
+ if ((*V1)[i1].Value < (*V2)[i2].Value)
+ ++i1;
+ else
+ ++i2;
+ }
+ return false;
+}
+
/// SimplifyEqualityComparisonWithOnlyPredecessor - If TI is known to be a
/// terminator instruction and its block is known to only have a single
/// predecessor block, check to see if that predecessor is also a value
@@ -555,27 +616,23 @@
if (ThisVal != PredVal) return false; // Different predicates.
// Find out information about when control will move from Pred to TI's block.
- IntegersSubsetToBB PredCases;
+ std::vector<ValueEqualityComparisonCase> PredCases;
BasicBlock *PredDef = GetValueEqualityComparisonCases(Pred->getTerminator(),
PredCases);
+ EliminateBlockCases(PredDef, PredCases); // Remove default from cases.
- // Remove default from cases.
- PredCases.removeCase(PredDef);
-
// Find information about how control leaves this block.
- IntegersSubsetToBB ThisCases;
+ std::vector<ValueEqualityComparisonCase> ThisCases;
BasicBlock *ThisDef = GetValueEqualityComparisonCases(TI, ThisCases);
+ EliminateBlockCases(ThisDef, ThisCases); // Remove default from cases.
- // Remove default from cases.
- ThisCases.removeCase(ThisDef);
-
// If TI's block is the default block from Pred's comparison, potentially
// simplify TI based on this knowledge.
if (PredDef == TI->getParent()) {
// If we are here, we know that the value is none of those cases listed in
// PredCases. If there are any cases in ThisCases that are in PredCases, we
// can simplify TI.
- if (!PredCases.isOverlapped(ThisCases))
+ if (!ValuesOverlap(PredCases, ThisCases))
return false;
if (isa<BranchInst>(TI)) {
@@ -587,7 +644,7 @@
(void) NI;
// Remove PHI node entries for the dead edge.
- ThisCases.begin()->second->removePredecessor(TI->getParent());
+ ThisCases[0].Dest->removePredecessor(TI->getParent());
DEBUG(dbgs() << "Threading pred instr: " << *Pred->getTerminator()
<< "Through successor TI: " << *TI << "Leaving: " << *NI << "\n");
@@ -598,45 +655,45 @@
SwitchInst *SI = cast<SwitchInst>(TI);
// Okay, TI has cases that are statically dead, prune them away.
- IRBuilder<> CodeBuilder(SI);
- CodeBuilder.SetCurrentDebugLocation(SI->getDebugLoc());
+ SmallPtrSet<Constant*, 16> DeadCases;
+ for (unsigned i = 0, e = PredCases.size(); i != e; ++i)
+ DeadCases.insert(PredCases[i].Value);
DEBUG(dbgs() << "Threading pred instr: " << *Pred->getTerminator()
<< "Through successor TI: " << *TI);
- // Okay, TI has cases that are statically dead, prune them away.
- IntegersSubsetToBB NewThisCases;
- IntegersSubsetToBB WastedCases;
- ThisCases.diff(&NewThisCases, &WastedCases, 0, PredCases);
-
- IntegersSubsetToBB::Cases Cases;
- NewThisCases.getCases(Cases, true/*temporary prevent complex cases*/);
-
- SwitchInst *NewSI =
- CodeBuilder.CreateSwitch(ThisVal, SI->getDefaultDest(), Cases.size());
-
- for (IntegersSubsetToBB::RangeIterator i = WastedCases.begin(),
- e = WastedCases.end(); i != e; ++i)
- i->second->removePredecessor(TI->getParent());
-
- for (IntegersSubsetToBB::CasesIt i = Cases.begin(), e = Cases.end();
- i != e; ++i)
- NewSI->addCase(i->second, i->first);
-
- EraseTerminatorInstAndDCECond(SI);
- DEBUG(dbgs() << "Leaving: " << *NewSI << "\n");
+ for (SwitchInst::CaseIt i = SI->case_end(), e = SI->case_begin(); i != e;) {
+ --i;
+ if (DeadCases.count(i.getCaseValue())) {
+ i.getCaseSuccessor()->removePredecessor(TI->getParent());
+ SI->removeCase(i);
+ }
+ }
+
+ DEBUG(dbgs() << "Leaving: " << *TI << "\n");
return true;
}
// Otherwise, TI's block must correspond to some matched value. Find out
// which value (or set of values) this is.
+ ConstantInt *TIV = 0;
BasicBlock *TIBB = TI->getParent();
- const IntItem* TIVIntITem = PredCases.getCaseSingleNumber(TIBB);
- assert(TIVIntITem && "No edge from pred to succ?");
+ for (unsigned i = 0, e = PredCases.size(); i != e; ++i)
+ if (PredCases[i].Dest == TIBB) {
+ if (TIV != 0)
+ return false; // Cannot handle multiple values coming to this block.
+ TIV = PredCases[i].Value;
+ }
+ assert(TIV && "No edge from pred to succ?");
// Okay, we found the one constant that our value can be if we get into TI's
// BB. Find out which successor will unconditionally be branched to.
- BasicBlock *TheRealDest = ThisCases.findSuccessor(*TIVIntITem);
+ BasicBlock *TheRealDest = 0;
+ for (unsigned i = 0, e = ThisCases.size(); i != e; ++i)
+ if (ThisCases[i].Value == TIV) {
+ TheRealDest = ThisCases[i].Dest;
+ break;
+ }
// If not handled by any explicit cases, it is handled by the default case.
if (TheRealDest == 0) TheRealDest = ThisDef;
@@ -702,10 +759,10 @@
if (PCV == CV && SafeToMergeTerminators(TI, PTI)) {
// Figure out which 'cases' to copy from SI to PSI.
- IntegersSubsetToBB BBCases;
+ std::vector<ValueEqualityComparisonCase> BBCases;
BasicBlock *BBDefault = GetValueEqualityComparisonCases(TI, BBCases);
- IntegersSubsetToBB PredCases;
+ std::vector<ValueEqualityComparisonCase> PredCases;
BasicBlock *PredDefault = GetValueEqualityComparisonCases(PTI, PredCases);
// Based on whether the default edge from PTI goes to BB or not, fill in
@@ -716,51 +773,61 @@
if (PredDefault == BB) {
// If this is the default destination from PTI, only the edges in TI
// that don't occur in PTI, or that branch to BB will be activated.
-
- PredCases.removeCase(BB);
- IntegersSubsetToBB NewBBCases;
- BBCases.diff(&NewBBCases, 0, 0, PredCases);
- PredCases.add(NewBBCases);
- for (IntegersSubsetToBB::RangeIterator i = NewBBCases.begin(),
- e = NewBBCases.end(); i != e; ++i)
- NewSuccessors.push_back(i->second);
+ std::set<ConstantInt*, ConstantIntOrdering> PTIHandled;
+ for (unsigned i = 0, e = PredCases.size(); i != e; ++i)
+ if (PredCases[i].Dest != BB)
+ PTIHandled.insert(PredCases[i].Value);
+ else {
+ // The default destination is BB, we don't need explicit targets.
+ std::swap(PredCases[i], PredCases.back());
+ PredCases.pop_back();
+ --i; --e;
+ }
- // Replace the default if needed.
+ // Reconstruct the new switch statement we will be building.
if (PredDefault != BBDefault) {
PredDefault->removePredecessor(Pred);
PredDefault = BBDefault;
NewSuccessors.push_back(BBDefault);
}
+ for (unsigned i = 0, e = BBCases.size(); i != e; ++i)
+ if (!PTIHandled.count(BBCases[i].Value) &&
+ BBCases[i].Dest != BBDefault) {
+ PredCases.push_back(BBCases[i]);
+ NewSuccessors.push_back(BBCases[i].Dest);
+ }
} else {
// If this is not the default destination from PSI, only the edges
// in SI that occur in PSI with a destination of BB will be
// activated.
- IntegersSubsetToBB BBPredCase;
- PredCases.detachCase(BBPredCase, BB);
- IntegersSubsetToBB CasesWithBBDef;
- IntegersSubsetToBB InharitedCases;
+ std::set<ConstantInt*, ConstantIntOrdering> PTIHandled;
+ for (unsigned i = 0, e = PredCases.size(); i != e; ++i)
+ if (PredCases[i].Dest == BB) {
+ PTIHandled.insert(PredCases[i].Value);
+ std::swap(PredCases[i], PredCases.back());
+ PredCases.pop_back();
+ --i; --e;
+ }
// Okay, now we know which constants were sent to BB from the
// predecessor. Figure out where they will all go now.
- if (!BBPredCase.empty()) {
- BBCases.diff(
- 0, // LHS excl RHS
- &InharitedCases, // intersection
- &CasesWithBBDef, // RHS excl LHS
- BBPredCase); // RHS.
- }
- PredCases.add(InharitedCases);
- for (IntegersSubsetToBB::RangeIterator i = InharitedCases.begin(),
- e = InharitedCases.end();
- i != e; ++i)
- NewSuccessors.push_back(i->second);
-
+ for (unsigned i = 0, e = BBCases.size(); i != e; ++i)
+ if (PTIHandled.count(BBCases[i].Value)) {
+ // If this is one we are capable of getting...
+ PredCases.push_back(BBCases[i]);
+ NewSuccessors.push_back(BBCases[i].Dest);
+ PTIHandled.erase(BBCases[i].Value);// This constant is taken care of
+ }
+
// If there are any constants vectored to BB that TI doesn't handle,
// they must go to the default destination of TI.
- PredCases.add(CasesWithBBDef, BBDefault);
- for (unsigned i = 0, e = CasesWithBBDef.size(); i != e; ++i)
+ for (std::set<ConstantInt*, ConstantIntOrdering>::iterator I =
+ PTIHandled.begin(),
+ E = PTIHandled.end(); I != E; ++I) {
+ PredCases.push_back(ValueEqualityComparisonCase(*I, BBDefault));
NewSuccessors.push_back(BBDefault);
+ }
}
// Okay, at this point, we know which new successor Pred will get. Make
@@ -781,12 +848,8 @@
SwitchInst *NewSI = Builder.CreateSwitch(CV, PredDefault,
PredCases.size());
NewSI->setDebugLoc(PTI->getDebugLoc());
- IntegersSubsetToBB::Cases Cases;
- PredCases.getCases(Cases, true/*temporary prevent complex case*/);
-
- for (IntegersSubsetToBB::CasesIt i = Cases.begin(), e = Cases.end();
- i != e; ++i)
- NewSI->addCase(i->second, i->first);
+ for (unsigned i = 0, e = PredCases.size(); i != e; ++i)
+ NewSI->addCase(PredCases[i].Value, PredCases[i].Dest);
EraseTerminatorInstAndDCECond(PTI);