[llvm-commits] [llvm] r171436 - in /llvm/trunk/lib/Transforms/Vectorize: LoopVectorize.cpp LoopVectorize.h
Nadav Rotem
nrotem at apple.com
Wed Jan 2 16:52:28 PST 2013
Author: nadav
Date: Wed Jan 2 18:52:27 2013
New Revision: 171436
URL: http://llvm.org/viewvc/llvm-project?rev=171436&view=rev
Log:
LoopVectorizer: Add support for loop-unrolling during vectorization for increasing the ILP. At the moment this feature is disabled by default and this commit should not cause any functional changes.
Modified:
llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp
llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.h
Modified: llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp?rev=171436&r1=171435&r2=171436&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp Wed Jan 2 18:52:27 2013
@@ -42,6 +42,11 @@
VectorizationFactor("force-vector-width", cl::init(0), cl::Hidden,
cl::desc("Sets the SIMD width. Zero is autoselect."));
+static cl::opt<unsigned>
+VectorizationUnroll("force-vector-unroll", cl::init(1), cl::Hidden,
+ cl::desc("Sets the vectorization unroll count. "
+ "Zero is autoselect."));
+
static cl::opt<bool>
EnableIfConversion("enable-if-conversion", cl::init(true), cl::Hidden,
cl::desc("Enable if-conversion during vectorization."));
@@ -117,7 +122,7 @@
F->getParent()->getModuleIdentifier()<<"\n");
// If we decided that it is *legal* to vectorizer the loop then do it.
- InnerLoopVectorizer LB(L, SE, LI, DT, DL, VF);
+ InnerLoopVectorizer LB(L, SE, LI, DT, DL, VF, VectorizationUnroll);
LB.vectorize(&LVL);
DEBUG(verifyFunction(*L->getHeader()->getParent()));
@@ -180,7 +185,8 @@
return Shuf;
}
-Value *InnerLoopVectorizer::getConsecutiveVector(Value* Val, bool Negate) {
+Value *InnerLoopVectorizer::getConsecutiveVector(Value* Val, unsigned StartIdx,
+ bool Negate) {
assert(Val->getType()->isVectorTy() && "Must be a vector");
assert(Val->getType()->getScalarType()->isIntegerTy() &&
"Elem must be an integer");
@@ -191,8 +197,10 @@
SmallVector<Constant*, 8> Indices;
// Create a vector of consecutive numbers from zero to VF.
- for (int i = 0; i < VLen; ++i)
- Indices.push_back(ConstantInt::get(ITy, Negate ? (-i): i ));
+ for (int i = 0; i < VLen; ++i) {
+ int Idx = Negate ? (-i): i;
+ Indices.push_back(ConstantInt::get(ITy, StartIdx + Idx));
+ }
// Add the consecutive indices to the vector value.
Constant *Cv = ConstantVector::get(Indices);
@@ -244,18 +252,20 @@
return (SE->isLoopInvariant(SE->getSCEV(V), TheLoop));
}
-Value *InnerLoopVectorizer::getVectorValue(Value *V) {
+InnerLoopVectorizer::VectorParts&
+InnerLoopVectorizer::getVectorValue(Value *V) {
assert(V != Induction && "The new induction variable should not be used.");
assert(!V->getType()->isVectorTy() && "Can't widen a vector");
- // If we saved a vectorized copy of V, use it.
- Value *&MapEntry = WidenMap[V];
- if (MapEntry)
- return MapEntry;
- // Broadcast V and save the value for future uses.
+ // If we have this scalar in the map, return it.
+ if (WidenMap.has(V))
+ return WidenMap.get(V);
+
+ // If this scalar is unknown, assume that it is a constant or that it is
+ // loop invariant. Broadcast V and save the value for future uses.
Value *B = getBroadcastInstrs(V);
- MapEntry = B;
- return B;
+ WidenMap.splat(V, B);
+ return WidenMap.get(V);
}
Constant*
@@ -277,7 +287,7 @@
void InnerLoopVectorizer::scalarizeInstruction(Instruction *Instr) {
assert(!Instr->getType()->isAggregateType() && "Can't handle vectors");
// Holds vector parameters or scalars, in case of uniform vals.
- SmallVector<Value*, 8> Params;
+ SmallVector<VectorParts, 4> Params;
// Find all of the vectorized parameters.
for (unsigned op = 0, e = Instr->getNumOperands(); op != e; ++op) {
@@ -295,12 +305,14 @@
// If the src is an instruction that appeared earlier in the basic block
// then it should already be vectorized.
if (SrcInst && OrigLoop->contains(SrcInst)) {
- assert(WidenMap.count(SrcInst) && "Source operand is unavailable");
+ assert(WidenMap.has(SrcInst) && "Source operand is unavailable");
// The parameter is a vector value from earlier.
- Params.push_back(WidenMap[SrcInst]);
+ Params.push_back(WidenMap.get(SrcInst));
} else {
// The parameter is a scalar from outside the loop. Maybe even a constant.
- Params.push_back(SrcOp);
+ VectorParts Scalars;
+ Scalars.append(UF, SrcOp);
+ Params.push_back(Scalars);
}
}
@@ -309,39 +321,38 @@
// Does this instruction return a value ?
bool IsVoidRetTy = Instr->getType()->isVoidTy();
- Value *VecResults = 0;
- // If we have a return value, create an empty vector. We place the scalarized
- // instructions in this vector.
- if (!IsVoidRetTy)
- VecResults = UndefValue::get(VectorType::get(Instr->getType(), VF));
+ Value *UndefVec = IsVoidRetTy ? 0 :
+ UndefValue::get(VectorType::get(Instr->getType(), VF));
+ // Create a new entry in the WidenMap and initialize it to Undef or Null.
+ VectorParts &VecResults = WidenMap.splat(Instr, UndefVec);
// For each scalar that we create:
- for (unsigned i = 0; i < VF; ++i) {
- Instruction *Cloned = Instr->clone();
- if (!IsVoidRetTy)
- Cloned->setName(Instr->getName() + ".cloned");
- // Replace the operands of the cloned instrucions with extracted scalars.
- for (unsigned op = 0, e = Instr->getNumOperands(); op != e; ++op) {
- Value *Op = Params[op];
- // Param is a vector. Need to extract the right lane.
- if (Op->getType()->isVectorTy())
- Op = Builder.CreateExtractElement(Op, Builder.getInt32(i));
- Cloned->setOperand(op, Op);
- }
-
- // Place the cloned scalar in the new loop.
- Builder.Insert(Cloned);
-
- // If the original scalar returns a value we need to place it in a vector
- // so that future users will be able to use it.
- if (!IsVoidRetTy)
- VecResults = Builder.CreateInsertElement(VecResults, Cloned,
- Builder.getInt32(i));
+ for (unsigned Width = 0; Width < VF; ++Width) {
+ // For each vector unroll 'part':
+ for (unsigned Part = 0; Part < UF; ++Part) {
+ Instruction *Cloned = Instr->clone();
+ if (!IsVoidRetTy)
+ Cloned->setName(Instr->getName() + ".cloned");
+ // Replace the operands of the cloned instrucions with extracted scalars.
+ for (unsigned op = 0, e = Instr->getNumOperands(); op != e; ++op) {
+ Value *Op = Params[op][Part];
+ // Param is a vector. Need to extract the right lane.
+ if (Op->getType()->isVectorTy())
+ Op = Builder.CreateExtractElement(Op, Builder.getInt32(Width));
+ Cloned->setOperand(op, Op);
+ }
+
+ // Place the cloned scalar in the new loop.
+ Builder.Insert(Cloned);
+
+ // If the original scalar returns a value we need to place it in a vector
+ // so that future users will be able to use it.
+ if (!IsVoidRetTy)
+ VecResults[Part] = Builder.CreateInsertElement(VecResults[Part], Cloned,
+ Builder.getInt32(Width));
+ }
}
-
- if (!IsVoidRetTy)
- WidenMap[Instr] = VecResults;
}
Value*
@@ -503,7 +514,9 @@
// Generate the induction variable.
Induction = Builder.CreatePHI(IdxTy, 2, "index");
- Constant *Step = ConstantInt::get(IdxTy, VF);
+ // The loop step is equal to the vectorization factor (num of SIMD elements)
+ // times the unroll factor (num of SIMD instructions).
+ Constant *Step = ConstantInt::get(IdxTy, VF * UF);
// We may need to extend the index in case there is a type mismatch.
// We know that the count starts at zero and does not overflow.
@@ -521,8 +534,7 @@
// Now we need to generate the expression for N - (N % VF), which is
// the part that the vectorized body will execute.
- Constant *CIVF = ConstantInt::get(IdxTy, VF);
- Value *R = BinaryOperator::CreateURem(Count, CIVF, "n.mod.vf", Loc);
+ Value *R = BinaryOperator::CreateURem(Count, Step, "n.mod.vf", Loc);
Value *CountRoundDown = BinaryOperator::CreateSub(Count, R, "n.vec", Loc);
Value *IdxEndRoundDown = BinaryOperator::CreateAdd(CountRoundDown, StartIdx,
"end.idx.rnd.down", Loc);
@@ -775,7 +787,6 @@
for (PhiVector::iterator it = RdxPHIsToFix.begin(), e = RdxPHIsToFix.end();
it != e; ++it) {
PHINode *RdxPhi = *it;
- PHINode *VecRdxPhi = dyn_cast<PHINode>(WidenMap[RdxPhi]);
assert(RdxPhi && "Unable to recover vectorized PHI");
// Find the reduction variable descriptor.
@@ -791,8 +802,8 @@
Builder.SetInsertPoint(LoopBypassBlock->getTerminator());
// This is the vector-clone of the value that leaves the loop.
- Value *VectorExit = getVectorValue(RdxDesc.LoopExitInstr);
- Type *VecTy = VectorExit->getType();
+ VectorParts &VectorExit = getVectorValue(RdxDesc.LoopExitInstr);
+ Type *VecTy = VectorExit[0]->getType();
// Find the reduction identity variable. Zero for addition, or, xor,
// one for multiplication, -1 for And.
@@ -811,10 +822,17 @@
// Reductions do not have to start at zero. They can start with
// any loop invariant values.
- VecRdxPhi->addIncoming(VectorStart, VecPreheader);
- Value *Val =
- getVectorValue(RdxPhi->getIncomingValueForBlock(OrigLoop->getLoopLatch()));
- VecRdxPhi->addIncoming(Val, LoopVectorBody);
+ VectorParts &VecRdxPhi = WidenMap.get(RdxPhi);
+ BasicBlock *Latch = OrigLoop->getLoopLatch();
+ Value *LoopVal = RdxPhi->getIncomingValueForBlock(Latch);
+ VectorParts &Val = getVectorValue(LoopVal);
+ for (unsigned part = 0; part < UF; ++part) {
+ // Make sure to add the reduction stat value only to the
+ // first unroll part.
+ Value *StartVal = (part == 0) ? VectorStart : Identity;
+ cast<PHINode>(VecRdxPhi[part])->addIncoming(StartVal, VecPreheader);
+ cast<PHINode>(VecRdxPhi[part])->addIncoming(Val[part], LoopVectorBody);
+ }
// Before each round, move the insertion point right between
// the PHIs and the values we are going to write.
@@ -822,18 +840,54 @@
// instructions.
Builder.SetInsertPoint(LoopMiddleBlock->getFirstInsertionPt());
- // This PHINode contains the vectorized reduction variable, or
- // the initial value vector, if we bypass the vector loop.
- PHINode *NewPhi = Builder.CreatePHI(VecTy, 2, "rdx.vec.exit.phi");
- NewPhi->addIncoming(VectorStart, LoopBypassBlock);
- NewPhi->addIncoming(getVectorValue(RdxDesc.LoopExitInstr), LoopVectorBody);
+ VectorParts RdxParts;
+ for (unsigned part = 0; part < UF; ++part) {
+ // This PHINode contains the vectorized reduction variable, or
+ // the initial value vector, if we bypass the vector loop.
+ VectorParts &RdxExitVal = getVectorValue(RdxDesc.LoopExitInstr);
+ PHINode *NewPhi = Builder.CreatePHI(VecTy, 2, "rdx.vec.exit.phi");
+ Value *StartVal = (part == 0) ? VectorStart : Identity;
+ NewPhi->addIncoming(StartVal, LoopBypassBlock);
+ NewPhi->addIncoming(RdxExitVal[part], LoopVectorBody);
+ RdxParts.push_back(NewPhi);
+ }
+
+ // Reduce all of the unrolled parts into a single vector.
+ Value *ReducedPartRdx = RdxParts[0];
+ for (unsigned part = 1; part < UF; ++part) {
+ switch (RdxDesc.Kind) {
+ case LoopVectorizationLegality::IntegerAdd:
+ ReducedPartRdx =
+ Builder.CreateAdd(RdxParts[part], ReducedPartRdx, "add.rdx");
+ break;
+ case LoopVectorizationLegality::IntegerMult:
+ ReducedPartRdx =
+ Builder.CreateMul(RdxParts[part], ReducedPartRdx, "mul.rdx");
+ break;
+ case LoopVectorizationLegality::IntegerOr:
+ ReducedPartRdx =
+ Builder.CreateOr(RdxParts[part], ReducedPartRdx, "or.rdx");
+ break;
+ case LoopVectorizationLegality::IntegerAnd:
+ ReducedPartRdx =
+ Builder.CreateAnd(RdxParts[part], ReducedPartRdx, "and.rdx");
+ break;
+ case LoopVectorizationLegality::IntegerXor:
+ ReducedPartRdx =
+ Builder.CreateXor(RdxParts[part], ReducedPartRdx, "xor.rdx");
+ break;
+ default:
+ llvm_unreachable("Unknown reduction operation");
+ }
+ }
+
// VF is a power of 2 so we can emit the reduction using log2(VF) shuffles
// and vector ops, reducing the set of values being computed by half each
// round.
assert(isPowerOf2_32(VF) &&
"Reduction emission only supported for pow2 vectors!");
- Value *TmpVec = NewPhi;
+ Value *TmpVec = ReducedPartRdx;
SmallVector<Constant*, 32> ShuffleMask(VF, 0);
for (unsigned i = VF; i != 1; i >>= 1) {
// Move the upper half of the vector to the lower half.
@@ -922,27 +976,34 @@
}
}
-Value *InnerLoopVectorizer::createEdgeMask(BasicBlock *Src, BasicBlock *Dst) {
+InnerLoopVectorizer::VectorParts
+InnerLoopVectorizer::createEdgeMask(BasicBlock *Src, BasicBlock *Dst) {
assert(std::find(pred_begin(Dst), pred_end(Dst), Src) != pred_end(Dst) &&
"Invalid edge");
- Value *SrcMask = createBlockInMask(Src);
+ VectorParts SrcMask = createBlockInMask(Src);
// The terminator has to be a branch inst!
BranchInst *BI = dyn_cast<BranchInst>(Src->getTerminator());
assert(BI && "Unexpected terminator found");
- Value *EdgeMask = SrcMask;
if (BI->isConditional()) {
- EdgeMask = getVectorValue(BI->getCondition());
+ VectorParts EdgeMask = getVectorValue(BI->getCondition());
+
if (BI->getSuccessor(0) != Dst)
- EdgeMask = Builder.CreateNot(EdgeMask);
+ for (unsigned part = 0; part < UF; ++part)
+ EdgeMask[part] = Builder.CreateNot(EdgeMask[part]);
+
+ for (unsigned part = 0; part < UF; ++part)
+ EdgeMask[part] = Builder.CreateAnd(EdgeMask[part], SrcMask[part]);
+ return EdgeMask;
}
- return Builder.CreateAnd(EdgeMask, SrcMask);
+ return SrcMask;
}
-Value *InnerLoopVectorizer::createBlockInMask(BasicBlock *BB) {
+InnerLoopVectorizer::VectorParts
+InnerLoopVectorizer::createBlockInMask(BasicBlock *BB) {
assert(OrigLoop->contains(BB) && "Block is not a part of a loop");
// Loop incoming mask is all-one.
@@ -953,11 +1014,14 @@
// This is the block mask. We OR all incoming edges, and with zero.
Value *Zero = ConstantInt::get(IntegerType::getInt1Ty(BB->getContext()), 0);
- Value *BlockMask = getVectorValue(Zero);
+ VectorParts BlockMask = getVectorValue(Zero);
// For each pred:
- for (pred_iterator it = pred_begin(BB), e = pred_end(BB); it != e; ++it)
- BlockMask = Builder.CreateOr(BlockMask, createEdgeMask(*it, BB));
+ for (pred_iterator it = pred_begin(BB), e = pred_end(BB); it != e; ++it) {
+ VectorParts EM = createEdgeMask(*it, BB);
+ for (unsigned part = 0; part < UF; ++part)
+ BlockMask[part] = Builder.CreateOr(BlockMask[part], EM[part]);
+ }
return BlockMask;
}
@@ -969,6 +1033,7 @@
// For each instruction in the old loop.
for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; ++it) {
+ VectorParts &Entry = WidenMap.get(it);
switch (it->getOpcode()) {
case Instruction::Br:
// Nothing to do for PHIs and BR, since we already took care of the
@@ -978,11 +1043,12 @@
PHINode* P = cast<PHINode>(it);
// Handle reduction variables:
if (Legal->getReductionVars()->count(P)) {
- // This is phase one of vectorizing PHIs.
- Type *VecTy = VectorType::get(it->getType(), VF);
- WidenMap[it] =
- PHINode::Create(VecTy, 2, "vec.phi",
- LoopVectorBody->getFirstInsertionPt());
+ for (unsigned part = 0; part < UF; ++part) {
+ // This is phase one of vectorizing PHIs.
+ Type *VecTy = VectorType::get(it->getType(), VF);
+ Entry[part] = PHINode::Create(VecTy, 2, "vec.phi",
+ LoopVectorBody-> getFirstInsertionPt());
+ }
PV->push_back(P);
continue;
}
@@ -996,12 +1062,15 @@
// At this point we generate the predication tree. There may be
// duplications since this is a simple recursive scan, but future
// optimizations will clean it up.
- Value *Cond = createEdgeMask(P->getIncomingBlock(0), P->getParent());
- WidenMap[P] =
- Builder.CreateSelect(Cond,
- getVectorValue(P->getIncomingValue(0)),
- getVectorValue(P->getIncomingValue(1)),
- "predphi");
+ VectorParts Cond = createEdgeMask(P->getIncomingBlock(0),
+ P->getParent());
+
+ for (unsigned part = 0; part < UF; ++part) {
+ VectorParts &In0 = getVectorValue(P->getIncomingValue(0));
+ VectorParts &In1 = getVectorValue(P->getIncomingValue(1));
+ Entry[part] = Builder.CreateSelect(Cond[part], In0[part], In1[part],
+ "predphi");
+ }
continue;
}
@@ -1021,8 +1090,8 @@
Value *Broadcasted = getBroadcastInstrs(Induction);
// After broadcasting the induction variable we need to make the
// vector consecutive by adding 0, 1, 2 ...
- Value *ConsecutiveInduction = getConsecutiveVector(Broadcasted);
- WidenMap[OldInduction] = ConsecutiveInduction;
+ for (unsigned part = 0; part < UF; ++part)
+ Entry[part] = getConsecutiveVector(Broadcasted, VF * part, false);
continue;
}
case LoopVectorizationLegality::ReverseIntInduction:
@@ -1054,9 +1123,8 @@
Value *Broadcasted = getBroadcastInstrs(ReverseInd);
// After broadcasting the induction variable we need to make the
// vector consecutive by adding ... -3, -2, -1, 0.
- Value *ConsecutiveInduction = getConsecutiveVector(Broadcasted,
- true);
- WidenMap[it] = ConsecutiveInduction;
+ for (unsigned part = 0; part < UF; ++part)
+ Entry[part] = getConsecutiveVector(Broadcasted, -VF * part, true);
continue;
}
@@ -1065,19 +1133,21 @@
// This is the vector of results. Notice that we don't generate
// vector geps because scalar geps result in better code.
- Value *VecVal = UndefValue::get(VectorType::get(P->getType(), VF));
- for (unsigned int i = 0; i < VF; ++i) {
- Constant *Idx = ConstantInt::get(Induction->getType(), i);
- Value *GlobalIdx = Builder.CreateAdd(NormalizedIdx, Idx,
- "gep.idx");
- Value *SclrGep = Builder.CreateGEP(II.StartValue, GlobalIdx,
- "next.gep");
- VecVal = Builder.CreateInsertElement(VecVal, SclrGep,
- Builder.getInt32(i),
- "insert.gep");
+ for (unsigned part = 0; part < UF; ++part) {
+ Value *VecVal = UndefValue::get(VectorType::get(P->getType(), VF));
+ for (unsigned int i = 0; i < VF; ++i) {
+ Constant *Idx = ConstantInt::get(Induction->getType(),
+ i + part * VF);
+ Value *GlobalIdx = Builder.CreateAdd(NormalizedIdx, Idx,
+ "gep.idx");
+ Value *SclrGep = Builder.CreateGEP(II.StartValue, GlobalIdx,
+ "next.gep");
+ VecVal = Builder.CreateInsertElement(VecVal, SclrGep,
+ Builder.getInt32(i),
+ "insert.gep");
+ }
+ Entry[part] = VecVal;
}
-
- WidenMap[it] = VecVal;
continue;
}
@@ -1103,41 +1173,48 @@
case Instruction::Xor: {
// Just widen binops.
BinaryOperator *BinOp = dyn_cast<BinaryOperator>(it);
- Value *A = getVectorValue(it->getOperand(0));
- Value *B = getVectorValue(it->getOperand(1));
+ VectorParts &A = getVectorValue(it->getOperand(0));
+ VectorParts &B = getVectorValue(it->getOperand(1));
// Use this vector value for all users of the original instruction.
- Value *V = Builder.CreateBinOp(BinOp->getOpcode(), A, B);
- WidenMap[it] = V;
+ for (unsigned Part = 0; Part < UF; ++Part) {
+ Value *V = Builder.CreateBinOp(BinOp->getOpcode(), A[Part], B[Part]);
- // Update the NSW, NUW and Exact flags.
- BinaryOperator *VecOp = cast<BinaryOperator>(V);
- if (isa<OverflowingBinaryOperator>(BinOp)) {
- VecOp->setHasNoSignedWrap(BinOp->hasNoSignedWrap());
- VecOp->setHasNoUnsignedWrap(BinOp->hasNoUnsignedWrap());
+ // Update the NSW, NUW and Exact flags.
+ BinaryOperator *VecOp = cast<BinaryOperator>(V);
+ if (isa<OverflowingBinaryOperator>(BinOp)) {
+ VecOp->setHasNoSignedWrap(BinOp->hasNoSignedWrap());
+ VecOp->setHasNoUnsignedWrap(BinOp->hasNoUnsignedWrap());
+ }
+ if (isa<PossiblyExactOperator>(VecOp))
+ VecOp->setIsExact(BinOp->isExact());
+
+ Entry[Part] = V;
}
- if (isa<PossiblyExactOperator>(VecOp))
- VecOp->setIsExact(BinOp->isExact());
break;
}
case Instruction::Select: {
// Widen selects.
// If the selector is loop invariant we can create a select
// instruction with a scalar condition. Otherwise, use vector-select.
- Value *Cond = it->getOperand(0);
- bool InvariantCond = SE->isLoopInvariant(SE->getSCEV(Cond), OrigLoop);
+ bool InvariantCond = SE->isLoopInvariant(SE->getSCEV(it->getOperand(0)),
+ OrigLoop);
// The condition can be loop invariant but still defined inside the
// loop. This means that we can't just use the original 'cond' value.
// We have to take the 'vectorized' value and pick the first lane.
// Instcombine will make this a no-op.
- Cond = getVectorValue(Cond);
- if (InvariantCond)
- Cond = Builder.CreateExtractElement(Cond, Builder.getInt32(0));
-
- Value *Op0 = getVectorValue(it->getOperand(1));
- Value *Op1 = getVectorValue(it->getOperand(2));
- WidenMap[it] = Builder.CreateSelect(Cond, Op0, Op1);
+ VectorParts &Cond = getVectorValue(it->getOperand(0));
+ VectorParts &Op0 = getVectorValue(it->getOperand(1));
+ VectorParts &Op1 = getVectorValue(it->getOperand(2));
+ Value *ScalarCond = Builder.CreateExtractElement(Cond[0],
+ Builder.getInt32(0));
+ for (unsigned Part = 0; Part < UF; ++Part) {
+ Entry[Part] = Builder.CreateSelect(
+ InvariantCond ? ScalarCond : Cond[Part],
+ Op0[Part],
+ Op1[Part]);
+ }
break;
}
@@ -1146,12 +1223,16 @@
// Widen compares. Generate vector compares.
bool FCmp = (it->getOpcode() == Instruction::FCmp);
CmpInst *Cmp = dyn_cast<CmpInst>(it);
- Value *A = getVectorValue(it->getOperand(0));
- Value *B = getVectorValue(it->getOperand(1));
- if (FCmp)
- WidenMap[it] = Builder.CreateFCmp(Cmp->getPredicate(), A, B);
- else
- WidenMap[it] = Builder.CreateICmp(Cmp->getPredicate(), A, B);
+ VectorParts &A = getVectorValue(it->getOperand(0));
+ VectorParts &B = getVectorValue(it->getOperand(1));
+ for (unsigned Part = 0; Part < UF; ++Part) {
+ Value *C = 0;
+ if (FCmp)
+ C = Builder.CreateFCmp(Cmp->getPredicate(), A[Part], B[Part]);
+ else
+ C = Builder.CreateICmp(Cmp->getPredicate(), A[Part], B[Part]);
+ Entry[Part] = C;
+ }
break;
}
@@ -1173,12 +1254,17 @@
break;
}
+ // Handle consecutive stores.
+
GetElementPtrInst *Gep = dyn_cast<GetElementPtrInst>(Ptr);
if (Gep) {
// The last index does not have to be the induction. It can be
// consecutive and be a function of the index. For example A[I+1];
unsigned NumOperands = Gep->getNumOperands();
- Value *LastIndex = getVectorValue(Gep->getOperand(NumOperands - 1));
+
+ Value *LastGepOperand = Gep->getOperand(NumOperands - 1);
+ VectorParts &GEPParts = getVectorValue(LastGepOperand);
+ Value *LastIndex = GEPParts[0];
LastIndex = Builder.CreateExtractElement(LastIndex, Zero);
// Create the new GEP with the new induction variable.
@@ -1188,19 +1274,28 @@
} else {
// Use the induction element ptr.
assert(isa<PHINode>(Ptr) && "Invalid induction ptr");
- Ptr = Builder.CreateExtractElement(getVectorValue(Ptr), Zero);
+ VectorParts &PtrVal = getVectorValue(Ptr);
+ Ptr = Builder.CreateExtractElement(PtrVal[0], Zero);
}
- // If the address is consecutive but reversed, then the
- // wide load needs to start at the last vector element.
- if (Reverse)
- Ptr = Builder.CreateGEP(Ptr, Builder.getInt32(1 - VF));
-
- Ptr = Builder.CreateBitCast(Ptr, StTy->getPointerTo());
- Value *Val = getVectorValue(SI->getValueOperand());
- if (Reverse)
- Val = reverseVector(Val);
- Builder.CreateStore(Val, Ptr)->setAlignment(Alignment);
+ VectorParts &StoredVal = getVectorValue(SI->getValueOperand());
+ for (unsigned Part = 0; Part < UF; ++Part) {
+ // Calculate the pointer for the specific unroll-part.
+ Value *PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(Part * VF));
+
+ if (Reverse) {
+ // If we store to reverse consecutive memory locations then we need
+ // to reverse the order of elements in the stored value.
+ StoredVal[Part] = reverseVector(StoredVal[Part]);
+ // If the address is consecutive but reversed, then the
+ // wide store needs to start at the last vector element.
+ PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(-Part * VF));
+ PartPtr = Builder.CreateGEP(PartPtr, Builder.getInt32(1 - VF));
+ }
+
+ Value *VecPtr = Builder.CreateBitCast(PartPtr, StTy->getPointerTo());
+ Builder.CreateStore(StoredVal[Part], VecPtr)->setAlignment(Alignment);
+ }
break;
}
case Instruction::Load: {
@@ -1224,7 +1319,10 @@
// The last index does not have to be the induction. It can be
// consecutive and be a function of the index. For example A[I+1];
unsigned NumOperands = Gep->getNumOperands();
- Value *LastIndex = getVectorValue(Gep->getOperand(NumOperands -1));
+
+ Value *LastGepOperand = Gep->getOperand(NumOperands - 1);
+ VectorParts &GEPParts = getVectorValue(LastGepOperand);
+ Value *LastIndex = GEPParts[0];
LastIndex = Builder.CreateExtractElement(LastIndex, Zero);
// Create the new GEP with the new induction variable.
@@ -1234,19 +1332,26 @@
} else {
// Use the induction element ptr.
assert(isa<PHINode>(Ptr) && "Invalid induction ptr");
- Ptr = Builder.CreateExtractElement(getVectorValue(Ptr), Zero);
+ VectorParts &PtrVal = getVectorValue(Ptr);
+ Ptr = Builder.CreateExtractElement(PtrVal[0], Zero);
}
- // If the address is consecutive but reversed, then the
- // wide load needs to start at the last vector element.
- if (Reverse)
- Ptr = Builder.CreateGEP(Ptr, Builder.getInt32(1 - VF));
-
- Ptr = Builder.CreateBitCast(Ptr, RetTy->getPointerTo());
- LI = Builder.CreateLoad(Ptr);
- LI->setAlignment(Alignment);
- // Use this vector value for all users of the load.
- WidenMap[it] = Reverse ? reverseVector(LI) : LI;
+ for (unsigned Part = 0; Part < UF; ++Part) {
+ // Calculate the pointer for the specific unroll-part.
+ Value *PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(Part * VF));
+
+ if (Reverse) {
+ // If the address is consecutive but reversed, then the
+ // wide store needs to start at the last vector element.
+ PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(-Part * VF));
+ PartPtr = Builder.CreateGEP(PartPtr, Builder.getInt32(1 - VF));
+ }
+
+ Value *VecPtr = Builder.CreateBitCast(PartPtr, RetTy->getPointerTo());
+ Value *LI = Builder.CreateLoad(VecPtr, "wide.load");
+ cast<LoadInst>(LI)->setAlignment(Alignment);
+ Entry[Part] = Reverse ? reverseVector(LI) : LI;
+ }
break;
}
case Instruction::ZExt:
@@ -1271,13 +1376,16 @@
Value *ScalarCast = Builder.CreateCast(CI->getOpcode(), Induction,
CI->getType());
Value *Broadcasted = getBroadcastInstrs(ScalarCast);
- WidenMap[it] = getConsecutiveVector(Broadcasted);
+ for (unsigned Part = 0; Part < UF; ++Part)
+ Entry[Part] = getConsecutiveVector(Broadcasted, VF * Part, false);
break;
}
/// Vectorize casts.
- Value *A = getVectorValue(it->getOperand(0));
Type *DestTy = VectorType::get(CI->getType()->getScalarType(), VF);
- WidenMap[it] = Builder.CreateCast(CI->getOpcode(), A, DestTy);
+
+ VectorParts &A = getVectorValue(it->getOperand(0));
+ for (unsigned Part = 0; Part < UF; ++Part)
+ Entry[Part] = Builder.CreateCast(CI->getOpcode(), A[Part], DestTy);
break;
}
@@ -1286,12 +1394,16 @@
Module *M = BB->getParent()->getParent();
IntrinsicInst *II = cast<IntrinsicInst>(it);
Intrinsic::ID ID = II->getIntrinsicID();
- SmallVector<Value*, 4> Args;
- for (unsigned i = 0, ie = II->getNumArgOperands(); i != ie; ++i)
- Args.push_back(getVectorValue(II->getArgOperand(i)));
- Type *Tys[] = { VectorType::get(II->getType()->getScalarType(), VF) };
- Function *F = Intrinsic::getDeclaration(M, ID, Tys);
- WidenMap[it] = Builder.CreateCall(F, Args);
+ for (unsigned Part = 0; Part < UF; ++Part) {
+ SmallVector<Value*, 4> Args;
+ for (unsigned i = 0, ie = II->getNumArgOperands(); i != ie; ++i) {
+ VectorParts &Arg = getVectorValue(II->getArgOperand(i));
+ Args.push_back(Arg[Part]);
+ }
+ Type *Tys[] = { VectorType::get(II->getType()->getScalarType(), VF) };
+ Function *F = Intrinsic::getDeclaration(M, ID, Tys);
+ Entry[Part] = Builder.CreateCall(F, Args);
+ }
break;
}
Modified: llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.h?rev=171436&r1=171435&r2=171436&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.h (original)
+++ llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.h Wed Jan 2 18:52:27 2013
@@ -54,6 +54,8 @@
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/IR/IRBuilder.h"
#include <algorithm>
+#include <map>
+
using namespace llvm;
/// We don't vectorize loops with a known constant trip count below this number.
@@ -91,9 +93,11 @@
public:
/// Ctor.
InnerLoopVectorizer(Loop *Orig, ScalarEvolution *Se, LoopInfo *Li,
- DominatorTree *Dt, DataLayout *Dl, unsigned VecWidth):
+ DominatorTree *Dt, DataLayout *Dl,
+ unsigned VecWidth, unsigned UnrollFactor):
OrigLoop(Orig), SE(Se), LI(Li), DT(Dt), DL(Dl), VF(VecWidth),
- Builder(Se->getContext()), Induction(0), OldInduction(0) { }
+ UF(UnrollFactor), Builder(Se->getContext()), Induction(0), OldInduction(0),
+ WidenMap(UnrollFactor) { }
// Perform the actual loop widening (vectorization).
void vectorize(LoopVectorizationLegality *Legal) {
@@ -109,6 +113,10 @@
private:
/// A small list of PHINodes.
typedef SmallVector<PHINode*, 4> PhiVector;
+ /// When we unroll loops we have multiple vector values for each scalar.
+ /// This data structure holds the unrolled and vectorized values that
+ /// originated from one scalar instruction.
+ typedef SmallVector<Value*, 2> VectorParts;
/// Add code that checks at runtime if the accessed arrays overlap.
/// Returns the comparator value or NULL if no check is needed.
@@ -122,10 +130,10 @@
/// A helper function that computes the predicate of the block BB, assuming
/// that the header block of the loop is set to True. It returns the *entry*
/// mask for the block BB.
- Value *createBlockInMask(BasicBlock *BB);
+ VectorParts createBlockInMask(BasicBlock *BB);
/// A helper function that computes the predicate of the edge between SRC
/// and DST.
- Value *createEdgeMask(BasicBlock *Src, BasicBlock *Dst);
+ VectorParts createEdgeMask(BasicBlock *Src, BasicBlock *Dst);
/// A helper function to vectorize a single BB within the innermost loop.
void vectorizeBlockInLoop(LoopVectorizationLegality *Legal, BasicBlock *BB,
@@ -148,14 +156,15 @@
/// This function adds 0, 1, 2 ... to each vector element, starting at zero.
/// If Negate is set then negative numbers are added e.g. (0, -1, -2, ...).
- Value *getConsecutiveVector(Value* Val, bool Negate = false);
+ /// The sequence starts at StartIndex.
+ Value *getConsecutiveVector(Value* Val, unsigned StartIdx, bool Negate);
/// When we go over instructions in the basic block we rely on previous
/// values within the current basic block or on loop invariant values.
/// When we widen (vectorize) values we place them in the map. If the values
/// are not within the map, they have to be loop invariant, so we simply
/// broadcast them into a vector.
- Value *getVectorValue(Value *V);
+ VectorParts &getVectorValue(Value *V);
/// Get a uniform vector of constant integers. We use this to get
/// vectors of ones and zeros for the reduction code.
@@ -164,22 +173,61 @@
/// Generate a shuffle sequence that will reverse the vector Vec.
Value *reverseVector(Value *Vec);
- typedef DenseMap<Value*, Value*> ValueMap;
+ /// This is a helper class that holds the vectorizer state. It maps scalar
+ /// instructions to vector instructions. When the code is 'unrolled' then
+ /// then a single scalar value is mapped to multiple vector parts. The parts
+ /// are stored in the VectorPart type.
+ struct ValueMap {
+ /// C'tor. UnrollFactor controls the number of vectors ('parts') that
+ /// are mapped.
+ ValueMap(unsigned UnrollFactor) : UF(UnrollFactor) {}
+
+ /// \return True if 'Key' is saved in the Value Map.
+ bool has(Value *Key) { return MapStoreage.count(Key); }
+
+ /// Initializes a new entry in the map. Sets all of the vector parts to the
+ /// save value in 'Val'.
+ /// \return A reference to a vector with splat values.
+ VectorParts &splat(Value *Key, Value *Val) {
+ MapStoreage[Key].clear();
+ MapStoreage[Key].append(UF, Val);
+ return MapStoreage[Key];
+ }
+
+ ///\return A reference to the value that is stored at 'Key'.
+ VectorParts &get(Value *Key) {
+ if (!has(Key))
+ MapStoreage[Key].resize(UF);
+ return MapStoreage[Key];
+ }
+
+ /// The unroll factor. Each entry in the map stores this number of vector
+ /// elements.
+ unsigned UF;
+
+ /// Map storage. We use std::map and not DenseMap because insertions to a
+ /// dense map invalidates its iterators.
+ std::map<Value*, VectorParts> MapStoreage;
+ };
/// The original loop.
Loop *OrigLoop;
- // Scev analysis to use.
+ /// Scev analysis to use.
ScalarEvolution *SE;
- // Loop Info.
+ /// Loop Info.
LoopInfo *LI;
- // Dominator Tree.
+ /// Dominator Tree.
DominatorTree *DT;
- // Data Layout.
+ /// Data Layout.
DataLayout *DL;
- // The vectorization factor to use.
+ /// The vectorization SIMD factor to use. Each vector will have this many
+ /// vector elements.
unsigned VF;
+ /// The vectorization unroll factor to use. Each scalar is vectorized to this
+ /// many different vector instructions.
+ unsigned UF;
- // The builder that we use
+ /// The builder that we use
IRBuilder<> Builder;
// --- Vectorization state ---
@@ -203,7 +251,7 @@
PHINode *Induction;
/// The induction variable of the old basic block.
PHINode *OldInduction;
- // Maps scalars to widened vectors.
+ /// Maps scalars to widened vectors.
ValueMap WidenMap;
};
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