//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Scalar.h"
-#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/IR/CFG.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/LLVMContext.h"
-#include "llvm/IR/CFG.h"
#include "llvm/Pass.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h"
#include <algorithm>
using namespace llvm;
}
struct CaseRange {
- Constant* Low;
- Constant* High;
+ ConstantInt* Low;
+ ConstantInt* High;
BasicBlock* BB;
- CaseRange(Constant *low, Constant *high, BasicBlock *bb)
+ CaseRange(ConstantInt *low, ConstantInt *high, BasicBlock *bb)
: Low(low), High(high), BB(bb) {}
};
// Remove additional occurences coming from condensed cases and keep the
// number of incoming values equal to the number of branches to SuccBB.
+ SmallVector<unsigned, 8> Indices;
for (++Idx; LocalNumMergedCases > 0 && Idx < E; ++Idx)
if (PN->getIncomingBlock(Idx) == OrigBB) {
- PN->removeIncomingValue(Idx);
+ Indices.push_back(Idx);
LocalNumMergedCases--;
}
+ // Remove incoming values in the reverse order to prevent invalidating
+ // *successive* index.
+ for (auto III = Indices.rbegin(), IIE = Indices.rend(); III != IIE; ++III)
+ PN->removeIncomingValue(*III);
}
}
CaseRange &Pivot = *(Begin + Mid);
DEBUG(dbgs() << "Pivot ==> "
- << cast<ConstantInt>(Pivot.Low)->getValue()
- << " -" << cast<ConstantInt>(Pivot.High)->getValue() << "\n");
+ << Pivot.Low->getValue()
+ << " -" << Pivot.High->getValue() << "\n");
// NewLowerBound here should never be the integer minimal value.
// This is because it is computed from a case range that is never
// the smallest, so there is always a case range that has at least
// a smaller value.
- ConstantInt *NewLowerBound = cast<ConstantInt>(Pivot.Low);
+ ConstantInt *NewLowerBound = Pivot.Low;
// Because NewLowerBound is never the smallest representable integer
// it is safe here to subtract one.
if (!UnreachableRanges.empty()) {
// Check if the gap between LHS's highest and NewLowerBound is unreachable.
- int64_t GapLow = cast<ConstantInt>(LHS.back().High)->getSExtValue() + 1;
+ int64_t GapLow = LHS.back().High->getSExtValue() + 1;
int64_t GapHigh = NewLowerBound->getSExtValue() - 1;
IntRange Gap = { GapLow, GapHigh };
if (GapHigh >= GapLow && IsInRanges(Gap, UnreachableRanges))
- NewUpperBound = cast<ConstantInt>(LHS.back().High);
+ NewUpperBound = LHS.back().High;
}
DEBUG(dbgs() << "LHS Bounds ==> ";
if (LowerBound) {
- dbgs() << cast<ConstantInt>(LowerBound)->getSExtValue();
+ dbgs() << LowerBound->getSExtValue();
} else {
dbgs() << "NONE";
}
dbgs() << "RHS Bounds ==> ";
dbgs() << NewLowerBound->getSExtValue() << " - ";
if (UpperBound) {
- dbgs() << cast<ConstantInt>(UpperBound)->getSExtValue() << "\n";
+ dbgs() << UpperBound->getSExtValue() << "\n";
} else {
dbgs() << "NONE\n";
});
Leaf.Low, "SwitchLeaf");
} else {
// Make range comparison
- if (cast<ConstantInt>(Leaf.Low)->isMinValue(true /*isSigned*/)) {
+ if (Leaf.Low->isMinValue(true /*isSigned*/)) {
// Val >= Min && Val <= Hi --> Val <= Hi
Comp = new ICmpInst(*NewLeaf, ICmpInst::ICMP_SLE, Val, Leaf.High,
"SwitchLeaf");
- } else if (cast<ConstantInt>(Leaf.Low)->isZero()) {
+ } else if (Leaf.Low->isZero()) {
// Val >= 0 && Val <= Hi --> Val <=u Hi
Comp = new ICmpInst(*NewLeaf, ICmpInst::ICMP_ULE, Val, Leaf.High,
"SwitchLeaf");
for (BasicBlock::iterator I = Succ->begin(); isa<PHINode>(I); ++I) {
PHINode* PN = cast<PHINode>(I);
// Remove all but one incoming entries from the cluster
- uint64_t Range = cast<ConstantInt>(Leaf.High)->getSExtValue() -
- cast<ConstantInt>(Leaf.Low)->getSExtValue();
+ uint64_t Range = Leaf.High->getSExtValue() -
+ Leaf.Low->getSExtValue();
for (uint64_t j = 0; j < Range; ++j) {
PN->removeIncomingValue(OrigBlock);
}
std::sort(Cases.begin(), Cases.end(), CaseCmp());
// Merge case into clusters
- if (Cases.size()>=2)
- for (CaseItr I = Cases.begin(), J = std::next(Cases.begin());
- J != Cases.end();) {
- int64_t nextValue = cast<ConstantInt>(J->Low)->getSExtValue();
- int64_t currentValue = cast<ConstantInt>(I->High)->getSExtValue();
+ if (Cases.size() >= 2) {
+ CaseItr I = Cases.begin();
+ for (CaseItr J = std::next(I), E = Cases.end(); J != E; ++J) {
+ int64_t nextValue = J->Low->getSExtValue();
+ int64_t currentValue = I->High->getSExtValue();
BasicBlock* nextBB = J->BB;
BasicBlock* currentBB = I->BB;
// If the two neighboring cases go to the same destination, merge them
// into a single case.
- if ((nextValue-currentValue==1) && (currentBB == nextBB)) {
+ assert(nextValue > currentValue && "Cases should be strictly ascending");
+ if ((nextValue == currentValue + 1) && (currentBB == nextBB)) {
I->High = J->High;
- J = Cases.erase(J);
- } else {
- I = J++;
+ // FIXME: Combine branch weights.
+ } else if (++I != J) {
+ *I = *J;
}
}
+ Cases.erase(std::next(I), Cases.end());
+ }
for (CaseItr I=Cases.begin(), E=Cases.end(); I!=E; ++I, ++numCmps) {
if (I->Low != I->High)
// know that the value passed to the switch must be exactly one of the case
// values.
assert(!Cases.empty());
- LowerBound = cast<ConstantInt>(Cases.front().Low);
- UpperBound = cast<ConstantInt>(Cases.back().High);
+ LowerBound = Cases.front().Low;
+ UpperBound = Cases.back().High;
DenseMap<BasicBlock *, unsigned> Popularity;
unsigned MaxPop = 0;
IntRange R = { INT64_MIN, INT64_MAX };
UnreachableRanges.push_back(R);
for (const auto &I : Cases) {
- int64_t Low = cast<ConstantInt>(I.Low)->getSExtValue();
- int64_t High = cast<ConstantInt>(I.High)->getSExtValue();
+ int64_t Low = I.Low->getSExtValue();
+ int64_t High = I.High->getSExtValue();
IntRange &LastRange = UnreachableRanges.back();
if (LastRange.Low == Low) {
// cases.
assert(MaxPop > 0 && PopSucc);
Default = PopSucc;
- for (CaseItr I = Cases.begin(); I != Cases.end();) {
- if (I->BB == PopSucc)
- I = Cases.erase(I);
- else
- ++I;
- }
+ Cases.erase(std::remove_if(
+ Cases.begin(), Cases.end(),
+ [PopSucc](const CaseRange &R) { return R.BB == PopSucc; }),
+ Cases.end());
// If there are no cases left, just branch.
if (Cases.empty()) {