maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

LoopVectorize: Teach the cost model to query scalar costs as scalar types and not vectors of 1. 

llvm-svn: 166715
This commit is contained in:
Nadav Rotem 2012-10-25 21:03:48 +00:00
parent f0e8720054
commit 579042f71b
1 changed files with 61 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

102
llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
View File

@ -324,6 +324,11 @@ private:
/// width. Vector width of one means scalar.
unsigned getInstructionCost(Instruction *I, unsigned VF);
/// A helper function for converting Scalar types to vector types.
/// If the incoming type is void, we return void. If the VF is 1, we return
/// the scalar type.
static Type* ToVectorTy(Type *Scalar, unsigned VF);
/// The loop that we evaluate.
Loop *TheLoop;
/// Scev analysis.
@ -1478,8 +1483,16 @@ unsigned LoopVectorizationCostModel::expectedCost(unsigned VF) {
unsigned
LoopVectorizationCostModel::getInstructionCost(Instruction *I, unsigned VF) {
assert(VTTI && "Invalid vector target transformation info");
Type *RetTy = I->getType();
Type *VectorTy = ToVectorTy(RetTy, VF);
// TODO: We need to estimate the cost of intrinsic calls.
switch (I->getOpcode()) {
case Instruction::GetElementPtr:
// We mark this instruction as zero-cost because scalar GEPs are usually
// lowered to the intruction addressing mode. At the moment we don't
// generate vector geps.
return 0;
case Instruction::Br: {
return VTTI->getInstrCost(I->getOpcode());
@ -1504,74 +1517,76 @@ LoopVectorizationCostModel::getInstructionCost(Instruction *I, unsigned VF) {
case Instruction::And:
case Instruction::Or:
case Instruction::Xor: {
Type *VTy = VectorType::get(I->getType(), VF);
return VTTI->getInstrCost(I->getOpcode(), VTy);
return VTTI->getInstrCost(I->getOpcode(), VectorTy);
}
case Instruction::Select: {
SelectInst *SI = cast<SelectInst>(I);
Type *VTy = VectorType::get(I->getType(), VF);
const SCEV *CondSCEV = SE->getSCEV(SI->getCondition());
bool ScalarCond = (SE->isLoopInvariant(CondSCEV, TheLoop));
Type *CondTy = SI->getCondition()->getType();
if (ScalarCond)
CondTy = VectorType::get(CondTy, VF);
return VTTI->getInstrCost(I->getOpcode(), VTy, CondTy);
return VTTI->getInstrCost(I->getOpcode(), VectorTy, CondTy);
}
case Instruction::ICmp:
case Instruction::FCmp: {
Type *VTy = VectorType::get(I->getOperand(0)->getType(), VF);
return VTTI->getInstrCost(I->getOpcode(), VTy);
Type *ValTy = I->getOperand(0)->getType();
VectorTy = ToVectorTy(ValTy, VF);
return VTTI->getInstrCost(I->getOpcode(), VectorTy);
}
case Instruction::Store: {
StoreInst *SI = cast<StoreInst>(I);
Type *VTy = VectorType::get(SI->getValueOperand()->getType(), VF);
Type *ValTy = SI->getValueOperand()->getType();
VectorTy = ToVectorTy(ValTy, VF);
if (VF == 1)
return VTTI->getMemoryOpCost(I->getOpcode(), ValTy,
SI->getAlignment(), SI->getPointerAddressSpace());
// Scalarized stores.
if (!Legal->isConsecutiveGep(SI->getPointerOperand())) {
unsigned Cost = 0;
if (VF != 1) {
unsigned ExtCost = VTTI->getInstrCost(Instruction::ExtractElement,
VTy);
// The cost of extracting from the value vector and pointer vector.
Cost += VF * (ExtCost * 2);
}
unsigned ExtCost = VTTI->getInstrCost(Instruction::ExtractElement,
ValTy);
// The cost of extracting from the value vector.
Cost += VF * (ExtCost);
// The cost of the scalar stores.
Cost += VF * VTTI->getMemoryOpCost(I->getOpcode(),
VTy->getScalarType(),
ValTy->getScalarType(),
SI->getAlignment(),
SI->getPointerAddressSpace());
return Cost;
}
// Wide stores.
return VTTI->getMemoryOpCost(I->getOpcode(), VTy, SI->getAlignment(),
return VTTI->getMemoryOpCost(I->getOpcode(), VectorTy, SI->getAlignment(),
SI->getPointerAddressSpace());
}
case Instruction::Load: {
LoadInst *LI = cast<LoadInst>(I);
Type *VTy = VectorType::get(I->getType(), VF);
if (VF == 1)
return VTTI->getMemoryOpCost(I->getOpcode(), RetTy,
LI->getAlignment(),
LI->getPointerAddressSpace());
// Scalarized loads.
if (!Legal->isConsecutiveGep(LI->getPointerOperand())) {
unsigned Cost = 0;
if (VF != 1) {
unsigned InCost = VTTI->getInstrCost(Instruction::InsertElement, VTy);
unsigned ExCost = VTTI->getInstrCost(Instruction::ExtractValue, VTy);
// The cost of inserting the loaded value into the result vector, and
// extracting from a vector of pointers.
Cost += VF * (InCost + ExCost);
}
unsigned InCost = VTTI->getInstrCost(Instruction::InsertElement, RetTy);
// The cost of inserting the loaded value into the result vector.
Cost += VF * (InCost);
// The cost of the scalar stores.
Cost += VF * VTTI->getMemoryOpCost(I->getOpcode(), VTy->getScalarType(),
Cost += VF * VTTI->getMemoryOpCost(I->getOpcode(),
RetTy->getScalarType(),
LI->getAlignment(),
LI->getPointerAddressSpace());
return Cost;
}
// Wide loads.
return VTTI->getMemoryOpCost(I->getOpcode(), VTy, LI->getAlignment(),
return VTTI->getMemoryOpCost(I->getOpcode(), VectorTy, LI->getAlignment(),
LI->getPointerAddressSpace());
}
case Instruction::ZExt:
@ -1586,35 +1601,40 @@ LoopVectorizationCostModel::getInstructionCost(Instruction *I, unsigned VF) {
case Instruction::Trunc:
case Instruction::FPTrunc:
case Instruction::BitCast: {
Type *SrcTy = VectorType::get(I->getOperand(0)->getType(), VF);
Type *DstTy = VectorType::get(I->getType(), VF);
return VTTI->getInstrCost(I->getOpcode(), DstTy, SrcTy);
Type *SrcVecTy = ToVectorTy(I->getOperand(0)->getType(), VF);
return VTTI->getInstrCost(I->getOpcode(), VectorTy, SrcVecTy);
}
default: {
// We are scalarizing the instruction. Return the cost of the scalar
// instruction, plus the cost of insert and extract into vector
// elements, times the vector width.
unsigned Cost = 0;
Type *Ty = I->getType();
if (!Ty->isVoidTy()) {
Type *VTy = VectorType::get(Ty, VF);
unsigned InsCost = VTTI->getInstrCost(Instruction::InsertElement, VTy);
unsigned ExtCost = VTTI->getInstrCost(Instruction::ExtractElement, VTy);
Cost += VF * (InsCost + ExtCost);
}
bool IsVoid = RetTy->isVoidTy();
/// We don't have any information on the scalar instruction, but maybe
/// the target has.
/// TODO: This may be a target-specific intrinsic.
/// Need to add API for that.
Cost += VF * VTTI->getInstrCost(I->getOpcode(), Ty);
unsigned InsCost = (IsVoid ? 0 :
VTTI->getInstrCost(Instruction::InsertElement,
VectorTy));
unsigned ExtCost = VTTI->getInstrCost(Instruction::ExtractElement,
VectorTy);
// The cost of inserting the results plus extracting each one of the
// operands.
Cost += VF * (InsCost + ExtCost * I->getNumOperands());
// The cost of executing VF copies of the scalar instruction.
Cost += VF * VTTI->getInstrCost(I->getOpcode(), RetTy);
return Cost;
}
}// end of switch.
}
Type* LoopVectorizationCostModel::ToVectorTy(Type *Scalar, unsigned VF) {
if (Scalar->isVoidTy() || VF == 1)
return Scalar;
return VectorType::get(Scalar, VF);
}
} // namespace