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AVX-512 Loop Vectorizer: Cost calculation for interleave load/store patterns.

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X86 target does not provide any target specific cost calculation for interleave patterns.It uses the common target-independent calculation, which gives very high numbers. As a result, the scalar version is chosen in many cases. The situation on AVX-512 is even worse, since we have 3-src shuffles that significantly reduce the cost.

In this patch I calculate the cost on AVX-512. It will allow to compare interleave pattern with gather/scatter and choose a better solution (PR31426).

* Shiffle-broadcast cost will be changed in Simon's upcoming patch.

Differential Revision: https://reviews.llvm.org/D28118

llvm-svn: 290810
This commit is contained in:
Elena Demikhovsky
2017-01-02 10:37:52 +00:00
parent f7d84ee6ff
commit 21706cbd24
14 changed files with 1055 additions and 23 deletions
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32
llvm/lib/Analysis/CostModel.cpp
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@@ -97,6 +97,27 @@ static bool isReverseVectorMask(ArrayRef<int> Mask) {
return true;
}
static bool isSingleSourceVectorMask(ArrayRef<int> Mask) {
bool Vec0 = false;
bool Vec1 = false;
for (unsigned i = 0, NumVecElts = Mask.size(); i < NumVecElts; ++i) {
if (Mask[i] >= 0) {
if ((unsigned)Mask[i] >= NumVecElts)
Vec1 = true;
else
Vec0 = true;
}
}
return !(Vec0 && Vec1);
}
static bool isZeroEltBroadcastVectorMask(ArrayRef<int> Mask) {
for (unsigned i = 0; i < Mask.size(); ++i)
if (Mask[i] > 0)
return false;
return true;
}
static bool isAlternateVectorMask(ArrayRef<int> Mask) {
bool isAlternate = true;
unsigned MaskSize = Mask.size();
@@ -501,6 +522,17 @@ unsigned CostModelAnalysis::getInstructionCost(const Instruction *I) const {
if (isAlternateVectorMask(Mask))
return TTI->getShuffleCost(TargetTransformInfo::SK_Alternate,
VecTypOp0, 0, nullptr);
if (isZeroEltBroadcastVectorMask(Mask))
return TTI->getShuffleCost(TargetTransformInfo::SK_Broadcast,
VecTypOp0, 0, nullptr);
if (isSingleSourceVectorMask(Mask))
return TTI->getShuffleCost(TargetTransformInfo::SK_PermuteSingleSrc,
VecTypOp0, 0, nullptr);
return TTI->getShuffleCost(TargetTransformInfo::SK_PermuteTwoSrc,
VecTypOp0, 0, nullptr);
}
return -1;