torch-mlir/lib/Conversion/TorchToMhlo/MhloLegalizeUtils.cpp

365 lines
14 KiB
C++

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// Also available under a BSD-style license. See LICENSE.
//
//===----------------------------------------------------------------------===//
#include "./MhloLegalizeUtils.h"
#include "mlir-hlo/Dialect/mhlo/IR/hlo_ops.h"
#include "mlir/Dialect/Arithmetic/IR/Arithmetic.h"
#include "mlir/Dialect/Tensor/IR/Tensor.h"
#include "torch-mlir/Conversion/TorchToMhlo/TorchToMhlo.h"
#include "torch-mlir/Dialect/Torch/IR/TorchOps.h"
#include "torch-mlir/Dialect/Torch/Utils/Utils.h"
#include <numeric>
using namespace mlir;
using namespace mlir::torch;
using namespace mlir::torch::Torch;
namespace mlir {
namespace mhlo {
// Create a 32-bit float constant operator from a float
Value getMhloConstTensorSingleF32(PatternRewriter &rewriter, Operation *op,
float val) {
auto const_type = RankedTensorType::get({}, rewriter.getF32Type());
auto const_attr = DenseElementsAttr::get(const_type, val);
auto const_op =
rewriter.create<mhlo::ConstantOp>(op->getLoc(), const_type, const_attr);
return const_op.getResult();
}
// Create a 64-bit float constant operator from a double
Value getMhloConstTensorSingleF64(PatternRewriter &rewriter, Operation *op,
double val) {
auto const_type = RankedTensorType::get({}, rewriter.getF64Type());
auto const_attr = DenseElementsAttr::get(const_type, val);
auto const_op =
rewriter.create<mhlo::ConstantOp>(op->getLoc(), const_type, const_attr);
return const_op.getResult();
}
// Templated function to create a constant op for given type and shape.
// T: storage C type.
// Default template creates a constant tensor in T.
template <typename T>
llvm::Optional<Value> getConstTensor(PatternRewriter &rewriter, Operation *op,
ArrayRef<T> vec, ArrayRef<int64_t> shape) {
uint64_t num_total_elements = 1;
for (int64_t a : shape) {
num_total_elements *= a;
}
if (vec.size() != num_total_elements) {
op->emitOpError("getConstTensor(): number of elements mismatch.");
return llvm::None;
}
auto const_type =
RankedTensorType::get(shape, rewriter.getIntegerType(sizeof(T) * 8));
auto const_attr = DenseElementsAttr::get(const_type, vec);
auto const_op =
rewriter.create<mhlo::ConstantOp>(op->getLoc(), const_type, const_attr);
return const_op.getResult();
}
// Template specialization for APInt
template <>
llvm::Optional<Value> getConstTensor<APInt>(PatternRewriter &rewriter,
Operation *op, ArrayRef<APInt> vec,
ArrayRef<int64_t> shape) {
uint64_t num_total_elements = 1;
for (int64_t a : shape) {
num_total_elements *= a;
}
if (vec.size() != num_total_elements) {
op->emitOpError("getConstTensor(): number of elements mismatch.");
return llvm::None;
}
auto const_type = RankedTensorType::get(
shape, rewriter.getIntegerType(vec[0].getBitWidth()));
auto const_attr = DenseElementsAttr::get(const_type, vec);
auto const_op =
rewriter.create<mhlo::ConstantOp>(op->getLoc(), const_type, const_attr);
return const_op.getResult();
}
// Template specialization for float
template <>
llvm::Optional<Value> getConstTensor<float>(PatternRewriter &rewriter,
Operation *op, ArrayRef<float> vec,
ArrayRef<int64_t> shape) {
uint64_t num_total_elements = 1;
for (int64_t a : shape) {
num_total_elements *= a;
}
if (vec.size() != num_total_elements) {
op->emitOpError("getConstTensor(): number of elements mismatch.");
return llvm::None;
}
auto const_type = RankedTensorType::get(shape, rewriter.getF32Type());
auto const_attr = DenseElementsAttr::get(const_type, vec);
auto const_op =
rewriter.create<mhlo::ConstantOp>(op->getLoc(), const_type, const_attr);
return const_op.getResult();
}
template <>
llvm::Optional<Value>
getConstTensor<double>(PatternRewriter &rewriter, Operation *op,
ArrayRef<double> vec, ArrayRef<int64_t> shape) {
uint64_t num_total_elements = 1;
for (int64_t a : shape) {
num_total_elements *= a;
}
if (vec.size() != num_total_elements) {
op->emitOpError("getConstTensor(): number of elements mismatch.");
return llvm::None;
}
auto const_type = RankedTensorType::get(shape, rewriter.getF64Type());
auto const_attr = DenseElementsAttr::get(const_type, vec);
auto const_op =
rewriter.create<mhlo::ConstantOp>(op->getLoc(), const_type, const_attr);
return const_op.getResult();
}
// Template instantiation
template llvm::Optional<Value> getConstTensor<int32_t>(PatternRewriter &,
Operation *,
ArrayRef<int32_t> vec,
ArrayRef<int64_t> shape);
template llvm::Optional<Value> getConstTensor<int64_t>(PatternRewriter &,
Operation *,
ArrayRef<int64_t> vec,
ArrayRef<int64_t> shape);
template <typename T>
static bool isInValidRange(bool isFloat, const double &doubleValue, bool isInt,
const int64_t &intValue) {
if (isFloat) {
// Do a round-trip check here instead of numeric limits due to
// compiler warnings around double <-> int conversion.
return (doubleValue == static_cast<double>(static_cast<T>(doubleValue)));
} else {
assert(isInt);
return (intValue >= std::numeric_limits<T>::min()) &&
(intValue <= std::numeric_limits<T>::max());
}
return true;
}
template <typename T>
Value getSplatConstTensor(ConversionPatternRewriter &rewriter, Operation *op,
T val, Type dtype, llvm::ArrayRef<int64_t> dshape) {
auto const_type = RankedTensorType::get(dshape, dtype);
auto const_attr = SplatElementsAttr::get(const_type, val);
auto const_op =
rewriter.create<mhlo::ConstantOp>(op->getLoc(), const_type, const_attr);
return const_op.getResult();
}
Value scalarToMhloTensor(ConversionPatternRewriter &rewriter, Operation *op,
Value scalarValue, Type dtype) {
auto tensor = rewriter.create<tensor::FromElementsOp>(
op->getLoc(), ArrayRef<Value>{scalarValue});
auto dtype_tensor =
rewriter.create<mhlo::ConvertOp>(op->getLoc(), tensor, dtype);
return rewriter.create<mhlo::ReshapeOp>(
op->getLoc(), RankedTensorType::get(mlir::ArrayRef<int64_t>{}, dtype),
dtype_tensor);
}
Value promoteType(PatternRewriter &rewriter, Value input, TensorType outType) {
Operation *op = input.getDefiningOp();
TensorType in_type = input.getType().dyn_cast<TensorType>();
if (in_type.getElementType() != outType.getElementType()) {
TensorType promotedType =
in_type.cloneWith(in_type.getShape(), outType.getElementType());
return rewriter.create<mhlo::ConvertOp>(op->getLoc(), promotedType, input);
}
return input;
}
Value promoteAndBroadcast(ConversionPatternRewriter &rewriter, Value input,
TensorType outType) {
// Two tensors are “broadcastable” if the following rules hold:
// - Each tensor has at least one dimension.
// - When iterating over the dimension sizes, starting at the trailing
// dimension, the dimension sizes must either be equal, one of them is 1, or
// one of them does not exist.
Operation *op = input.getDefiningOp();
TensorType in_type = input.getType().dyn_cast<TensorType>();
if (in_type.getElementType() != outType.getElementType()) {
TensorType promoted_type =
in_type.cloneWith(in_type.getShape(), outType.getElementType());
input =
rewriter.create<mhlo::ConvertOp>(op->getLoc(), promoted_type, input);
}
ArrayRef<int64_t> inShape = in_type.getShape();
ArrayRef<int64_t> outShape = outType.getShape();
bool do_bcast = (inShape.size() != outShape.size());
SmallVector<int64_t> bcastDims;
for (size_t i = 0; i < inShape.size(); ++i) {
// iterating over the dimension sizes, starting at the trailing dimension
size_t outPos = outShape.size() - 1 - i;
size_t inPos = inShape.size() - 1 - i;
int64_t outDim = outShape[outPos];
int64_t inDim = inShape[inPos];
if (inDim == outDim) {
bcastDims.push_back(outPos);
} else if (inDim != outDim && inDim == 1) {
bcastDims.push_back(outPos);
do_bcast = true;
} else {
op->emitError("The size of tensor a (")
<< inDim << ")"
<< "must match the size of tensor b (" << outDim << ")"
<< "at non-singleton dimension " << inPos;
}
}
std::reverse(bcastDims.begin(), bcastDims.end());
if (!do_bcast) {
return input;
}
DenseIntElementsAttr bcast_attr = DenseIntElementsAttr::get(
RankedTensorType::get({static_cast<long int>(bcastDims.size())},
rewriter.getI64Type()),
bcastDims);
auto bcast_op = rewriter.create<mhlo::BroadcastInDimOp>(op->getLoc(), outType,
input, bcast_attr);
return bcast_op.getResult();
}
SmallVector<size_t> toPositiveDims(ArrayRef<int64_t> dims, int64_t rank) {
SmallVector<size_t> posDims;
posDims.reserve(rank);
std::transform(
dims.begin(), dims.end(), std::back_inserter(posDims),
[rank](int64_t d) -> size_t { return toPositiveDim(d, rank); });
return posDims;
}
FailureOr<SmallVector<Value, 4>>
getDimSizesOfTensor(PatternRewriter &rewriter, Operation *op, Value value,
ArrayRef<int64_t> inpDims) {
auto valueTy = value.getType().dyn_cast<RankedTensorType>();
if (!valueTy) {
return rewriter.notifyMatchFailure(
op, "getDimSizesOfTensor(): the input is not a ranked tensor");
}
auto rank = valueTy.getRank();
auto dims = toPositiveDims(inpDims, rank);
SmallVector<Value, 4> dimSizes;
dimSizes.reserve(dims.size());
auto loc = op->getLoc();
for (auto d : dims) {
dimSizes.emplace_back(rewriter.create<arith::IndexCastOp>(
loc, rewriter.getIntegerType(kMhloDimSizeBits),
rewriter.create<tensor::DimOp>(loc, value, d)));
}
return dimSizes;
}
FailureOr<SmallVector<Value, 4>>
getDimSizesOfTensor(PatternRewriter &rewriter, Operation *op, Value value) {
auto valueTy = value.getType().dyn_cast<RankedTensorType>();
if (!valueTy) {
return rewriter.notifyMatchFailure(
op, "getDimSizesOfTensor(): the input is not a ranked tensor");
}
auto rank = valueTy.getRank();
// Get int vector [0, 1, ..., rank-1]
std::vector<int64_t> dims(rank);
std::iota(dims.begin(), dims.end(), 0);
return getDimSizesOfTensor(rewriter, op, value, dims);
}
FailureOr<Value> unsqueezeTensor(PatternRewriter &rewriter, Operation *op,
Value tensor,
ArrayRef<int64_t> inputUnsqzDims) {
// Returns a new tensor with dims of size 1 inserted at the specified
// position.
//
// The position indices (must be high to low dimension number of the returned
// tensor) are specified with unsqzDims. Indices must be in-order, and in
// range of tensor rank. Thus, unsqueeze a rank 1 tensor with {0, 2}, {0, 1,
// 3}, {0, 1, 2} are all valid dimension sets, but {0, 3}, {2} are not.
auto dimSizesInfo = getDimSizesOfTensor(rewriter, op, tensor);
if (failed(dimSizesInfo))
return rewriter.notifyMatchFailure(
op, "failed to get dimension sizes of the input");
auto dimSizes = *dimSizesInfo;
auto rank = dimSizes.size();
size_t newRank = rank + inputUnsqzDims.size();
auto unsqzDims = toPositiveDims(inputUnsqzDims, newRank);
for (size_t k = 0, sz = unsqzDims.size(); k < sz; ++k)
if (k > 1 && unsqzDims[k] <= unsqzDims[k - 1])
return rewriter.notifyMatchFailure(
op, "unsqueeze dimensions must be specified in order");
auto loc = op->getLoc();
auto rankTy = tensor.getType().dyn_cast<RankedTensorType>();
auto oldShape = rankTy.getShape();
Type intType = rewriter.getIntegerType(kMhloDimSizeBits);
auto one = rewriter.create<arith::ConstantOp>(
loc, rewriter.getIntegerAttr(intType, 1));
std::vector<Value> newDimSizes;
std::vector<int64_t> newShape;
newDimSizes.reserve(newRank);
newShape.reserve(newRank);
for (size_t k = 0, i = 0, j = 0; k < newRank; ++k) {
if (j < unsqzDims.size() && unsqzDims[j] == k) {
newDimSizes.push_back(one);
newShape.push_back(1);
j++;
} else {
newDimSizes.push_back(dimSizes[i]);
newShape.push_back(oldShape[i]);
i++;
}
}
auto outTy = RankedTensorType::get(newShape, rankTy.getElementType());
auto mhloShape = rewriter.create<tensor::FromElementsOp>(loc, newDimSizes);
return rewriter.create<mhlo::DynamicReshapeOp>(loc, outTy, tensor, mhloShape)
.getResult();
}
Value getConstantOfShape(PatternRewriter &rewriter, Location loc,
const APFloat &constant, Value shape,
TensorType outType) {
auto constAttr = rewriter.getFloatAttr(outType.getElementType(), constant);
auto constTensor = rewriter.create<mhlo::ConstantOp>(loc, constAttr);
return rewriter
.create<mhlo::DynamicBroadcastInDimOp>(loc, outType, constTensor, shape,
rewriter.getI64TensorAttr({}))
.getResult();
}
} // namespace mhlo
} // namespace mlir