/// different operations.
class LoopVectorizationCostModel {
public:
- LoopVectorizationCostModel(Loop *L, PredicatedScalarEvolution &PSE,
- LoopInfo *LI, LoopVectorizationLegality *Legal,
+ LoopVectorizationCostModel(Loop *L, ScalarEvolution *SE, LoopInfo *LI,
+ LoopVectorizationLegality *Legal,
const TargetTransformInfo &TTI,
const TargetLibraryInfo *TLI, DemandedBits *DB,
AssumptionCache *AC, const Function *F,
- const LoopVectorizeHints *Hints)
- : TheLoop(L), PSE(PSE), LI(LI), Legal(Legal), TTI(TTI), TLI(TLI), DB(DB),
- AC(AC), TheFunction(F), Hints(Hints) {}
+ const LoopVectorizeHints *Hints,
+ SmallPtrSetImpl<const Value *> &ValuesToIgnore)
+ : TheLoop(L), SE(SE), LI(LI), Legal(Legal), TTI(TTI), TLI(TLI), DB(DB),
+ TheFunction(F), Hints(Hints), ValuesToIgnore(ValuesToIgnore) {}
/// Information about vectorization costs
struct VectorizationFactor {
SmallVector<RegisterUsage, 8>
calculateRegisterUsage(const SmallVector<unsigned, 8> &VFs);
- /// Collect values we want to ignore in the cost model.
- void collectValuesToIgnore();
-
private:
/// Returns the expected execution cost. The unit of the cost does
/// not matter because we use the 'cost' units to compare different
/// The loop that we evaluate.
Loop *TheLoop;
- /// Predicated scalar evolution analysis.
- PredicatedScalarEvolution &PSE;
+ /// Scev analysis.
+ ScalarEvolution *SE;
/// Loop Info analysis.
LoopInfo *LI;
/// Vectorization legality.
const TargetTransformInfo &TTI;
/// Target Library Info.
const TargetLibraryInfo *TLI;
- /// Demanded bits analysis.
+ /// Demanded bits analysis
DemandedBits *DB;
- /// Assumption cache.
- AssumptionCache *AC;
const Function *TheFunction;
- /// Loop Vectorize Hint.
+ // Loop Vectorize Hint.
const LoopVectorizeHints *Hints;
- /// Values to ignore in the cost model.
- SmallPtrSet<const Value *, 16> ValuesToIgnore;
- /// Values to ignore in the cost model when VF > 1.
- SmallPtrSet<const Value *, 16> VecValuesToIgnore;
+ // Values to ignore in the cost model.
+ const SmallPtrSetImpl<const Value *> &ValuesToIgnore;
};
/// \brief This holds vectorization requirements that must be verified late in
return false;
}
+ // Collect values we want to ignore in the cost model. This includes
+ // type-promoting instructions we identified during reduction detection.
+ SmallPtrSet<const Value *, 32> ValuesToIgnore;
+ CodeMetrics::collectEphemeralValues(L, AC, ValuesToIgnore);
+ for (auto &Reduction : *LVL.getReductionVars()) {
+ RecurrenceDescriptor &RedDes = Reduction.second;
+ SmallPtrSetImpl<Instruction *> &Casts = RedDes.getCastInsts();
+ ValuesToIgnore.insert(Casts.begin(), Casts.end());
+ }
+
// Use the cost model.
- LoopVectorizationCostModel CM(L, PSE, LI, &LVL, *TTI, TLI, DB, AC, F,
- &Hints);
- CM.collectValuesToIgnore();
+ LoopVectorizationCostModel CM(L, PSE.getSE(), LI, &LVL, *TTI, TLI, DB, AC,
+ F, &Hints, ValuesToIgnore);
// Check the function attributes to find out if this function should be
// optimized for size.
}
// Find the trip count.
- unsigned TC = PSE.getSE()->getSmallConstantTripCount(TheLoop);
+ unsigned TC = SE->getSmallConstantTripCount(TheLoop);
DEBUG(dbgs() << "LV: Found trip count: " << TC << '\n');
MinBWs = computeMinimumValueSizes(TheLoop->getBlocks(), *DB, &TTI);
return 1;
// Do not interleave loops with a relatively small trip count.
- unsigned TC = PSE.getSE()->getSmallConstantTripCount(TheLoop);
+ unsigned TC = SE->getSmallConstantTripCount(TheLoop);
if (TC > 1 && TC < TinyTripCountInterleaveThreshold)
return 1;
// Ignore instructions that are never used within the loop.
if (!Ends.count(I)) continue;
+ // Skip ignored values.
+ if (ValuesToIgnore.count(I))
+ continue;
+
// Remove all of the instructions that end at this location.
InstrList &List = TransposeEnds[i];
for (unsigned int j = 0, e = List.size(); j < e; ++j)
OpenIntervals.erase(List[j]);
- // Skip ignored values.
- if (ValuesToIgnore.count(I))
- continue;
-
// For each VF find the maximum usage of registers.
for (unsigned j = 0, e = VFs.size(); j < e; ++j) {
if (VFs[j] == 1) {
// Count the number of live intervals.
unsigned RegUsage = 0;
- for (auto Inst : OpenIntervals) {
- // Skip ignored values for VF > 1.
- if (VecValuesToIgnore.count(Inst))
- continue;
+ for (auto Inst : OpenIntervals)
RegUsage += GetRegUsage(Inst->getType(), VFs[j]);
- }
MaxUsages[j] = std::max(MaxUsages[j], RegUsage);
}
if (VF > 1 && MinBWs.count(I))
RetTy = IntegerType::get(RetTy->getContext(), MinBWs[I]);
Type *VectorTy = ToVectorTy(RetTy, VF);
- auto SE = PSE.getSE();
// TODO: We need to estimate the cost of intrinsic calls.
switch (I->getOpcode()) {
return false;
}
-void LoopVectorizationCostModel::collectValuesToIgnore() {
- // Ignore ephemeral values.
- CodeMetrics::collectEphemeralValues(TheLoop, AC, ValuesToIgnore);
-
- // Ignore type-promoting instructions we identified during reduction
- // detection.
- for (auto &Reduction : *Legal->getReductionVars()) {
- RecurrenceDescriptor &RedDes = Reduction.second;
- SmallPtrSetImpl<Instruction *> &Casts = RedDes.getCastInsts();
- VecValuesToIgnore.insert(Casts.begin(), Casts.end());
- }
-
- // Ignore induction phis that are only used in either GetElementPtr or ICmp
- // instruction to exit loop. Induction variables usually have large types and
- // can have big impact when estimating register usage.
- // This is for when VF > 1.
- for (auto &Induction : *Legal->getInductionVars()) {
- auto *PN = Induction.first;
- auto *UpdateV = PN->getIncomingValueForBlock(TheLoop->getLoopLatch());
-
- // Check that the PHI is only used by the induction increment (UpdateV) or
- // by GEPs. Then check that UpdateV is only used by a compare instruction or
- // the loop header PHI.
- // FIXME: Need precise def-use analysis to determine if this instruction
- // variable will be vectorized.
- if (std::all_of(PN->user_begin(), PN->user_end(),
- [&](const User *U) -> bool {
- return U == UpdateV || isa<GetElementPtrInst>(U);
- }) &&
- std::all_of(UpdateV->user_begin(), UpdateV->user_end(),
- [&](const User *U) -> bool {
- return U == PN || isa<ICmpInst>(U);
- })) {
- VecValuesToIgnore.insert(PN);
- VecValuesToIgnore.insert(UpdateV);
- }
- }
-
- // Ignore instructions that will not be vectorized.
- // This is for when VF > 1.
- for (auto bb = TheLoop->block_begin(), be = TheLoop->block_end(); bb != be;
- ++bb) {
- for (auto &Inst : **bb) {
- switch (Inst.getOpcode()) {
- case Instruction::GetElementPtr: {
- // Ignore GEP if its last operand is an induction variable so that it is
- // a consecutive load/store and won't be vectorized as scatter/gather
- // pattern.
-
- GetElementPtrInst *Gep = cast<GetElementPtrInst>(&Inst);
- unsigned NumOperands = Gep->getNumOperands();
- unsigned InductionOperand = getGEPInductionOperand(Gep);
- bool GepToIgnore = true;
-
- // Check that all of the gep indices are uniform except for the
- // induction operand.
- for (unsigned i = 0; i != NumOperands; ++i) {
- if (i != InductionOperand &&
- !PSE.getSE()->isLoopInvariant(PSE.getSCEV(Gep->getOperand(i)),
- TheLoop)) {
- GepToIgnore = false;
- break;
- }
- }
-
- if (GepToIgnore)
- VecValuesToIgnore.insert(&Inst);
- break;
- }
- }
- }
- }
-}
void InnerLoopUnroller::scalarizeInstruction(Instruction *Instr,
bool IfPredicateStore) {
+++ /dev/null
-; RUN: opt < %s -mtriple=x86_64-unknown-unknown -mattr=+sse2 -debug-only=loop-vectorize -loop-vectorize -vectorizer-maximize-bandwidth 2>&1 | FileCheck %s
-
-
-@a = global [1024 x i8] zeroinitializer, align 16
-@b = global [1024 x i8] zeroinitializer, align 16
-
-define i32 @foo() {
-; This function has a loop of SAD pattern. Here we check when VF = 16 the
-; register usage doesn't exceed 16.
-;
-; CHECK-LABEL: foo
-; CHECK: LV(REG): VF = 4
-; CHECK-NEXT: LV(REG): Found max usage: 4
-; CHECK: LV(REG): VF = 8
-; CHECK-NEXT: LV(REG): Found max usage: 7
-; CHECK: LV(REG): VF = 16
-; CHECK-NEXT: LV(REG): Found max usage: 13
-
-entry:
- br label %for.body
-
-for.cond.cleanup:
- %add.lcssa = phi i32 [ %add, %for.body ]
- ret i32 %add.lcssa
-
-for.body:
- %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
- %s.015 = phi i32 [ 0, %entry ], [ %add, %for.body ]
- %arrayidx = getelementptr inbounds [1024 x i8], [1024 x i8]* @a, i64 0, i64 %indvars.iv
- %0 = load i8, i8* %arrayidx, align 1
- %conv = zext i8 %0 to i32
- %arrayidx2 = getelementptr inbounds [1024 x i8], [1024 x i8]* @b, i64 0, i64 %indvars.iv
- %1 = load i8, i8* %arrayidx2, align 1
- %conv3 = zext i8 %1 to i32
- %sub = sub nsw i32 %conv, %conv3
- %ispos = icmp sgt i32 %sub, -1
- %neg = sub nsw i32 0, %sub
- %2 = select i1 %ispos, i32 %sub, i32 %neg
- %add = add nsw i32 %2, %s.015
- %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
- %exitcond = icmp eq i64 %indvars.iv.next, 1024
- br i1 %exitcond, label %for.cond.cleanup, label %for.body
-}
-
-define i64 @bar(i64* nocapture %a) {
-; CHECK-LABEL: bar
-; CHECK: LV(REG): VF = 2
-; CHECK: LV(REG): Found max usage: 4
-;
-entry:
- br label %for.body
-
-for.cond.cleanup:
- %add2.lcssa = phi i64 [ %add2, %for.body ]
- ret i64 %add2.lcssa
-
-for.body:
- %i.012 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
- %s.011 = phi i64 [ 0, %entry ], [ %add2, %for.body ]
- %arrayidx = getelementptr inbounds i64, i64* %a, i64 %i.012
- %0 = load i64, i64* %arrayidx, align 8
- %add = add nsw i64 %0, %i.012
- store i64 %add, i64* %arrayidx, align 8
- %add2 = add nsw i64 %add, %s.011
- %inc = add nuw nsw i64 %i.012, 1
- %exitcond = icmp eq i64 %inc, 1024
- br i1 %exitcond, label %for.cond.cleanup, label %for.body
-}
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