llvm-project/mlir/lib/Dialect/Bufferization/IR/BufferizableOpInterface.cpp

804 lines
31 KiB
C++

//===- BufferizableOpInterface.cpp - Bufferizable Ops ---=----------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "mlir/Dialect/Bufferization/IR/BufferizableOpInterface.h"
#include "mlir/Dialect/Bufferization/IR/Bufferization.h"
#include "mlir/Dialect/Func/IR/FuncOps.h"
#include "mlir/Dialect/MemRef/IR/MemRef.h"
#include "mlir/Dialect/Tensor/IR/Tensor.h"
#include "mlir/IR/AsmState.h"
#include "mlir/IR/BlockAndValueMapping.h"
#include "mlir/IR/BuiltinOps.h"
#include "mlir/IR/Operation.h"
#include "mlir/IR/TypeUtilities.h"
#include "mlir/IR/Value.h"
#include "mlir/Interfaces/ControlFlowInterfaces.h"
#include "llvm/Support/Debug.h"
//===----------------------------------------------------------------------===//
// BufferizableOpInterface
//===----------------------------------------------------------------------===//
namespace mlir {
namespace bufferization {
#include "mlir/Dialect/Bufferization/IR/BufferizableOpInterface.cpp.inc"
} // namespace bufferization
} // namespace mlir
MLIR_DEFINE_EXPLICIT_TYPE_ID(mlir::bufferization::AnalysisState)
#define DEBUG_TYPE "bufferizable-op-interface"
#define DBGS() (llvm::dbgs() << '[' << DEBUG_TYPE << "] ")
#define LDBG(X) LLVM_DEBUG(DBGS() << (X))
using namespace mlir;
using namespace bufferization;
Operation *bufferization::getOwnerOfValue(Value value) {
if (auto opResult = value.dyn_cast<OpResult>())
return opResult.getDefiningOp();
return value.cast<BlockArgument>().getOwner()->getParentOp();
}
bool bufferization::allocationDoesNotEscape(OpResult opResult) {
#ifndef NDEBUG
auto bufferizableOp = opResult.getDefiningOp<BufferizableOpInterface>();
assert(bufferizableOp && bufferizableOp.bufferizesToAllocation(opResult) &&
"expected op that bufferizes to an allocation");
#endif // NDEBUG
Operation *op = opResult.getDefiningOp();
// If there is no 'escape' attribute, we cannot say for sure.
if (!op->hasAttr(BufferizationDialect::kEscapeAttrName))
return false;
auto attr =
op->getAttrOfType<ArrayAttr>(BufferizationDialect::kEscapeAttrName);
return !attr[opResult.getResultNumber()].cast<BoolAttr>().getValue();
}
/// Create an AllocTensorOp for the given shaped value. If `copy` is set, the
/// shaped value is copied. Otherwise, a tensor with undefined contents is
/// allocated.
FailureOr<Value> bufferization::allocateTensorForShapedValue(
OpBuilder &b, Location loc, Value shapedValue, bool escape,
const BufferizationOptions &options, bool copy) {
Value tensor;
if (shapedValue.getType().isa<RankedTensorType>()) {
tensor = shapedValue;
} else if (shapedValue.getType().isa<MemRefType>()) {
tensor = b.create<ToTensorOp>(loc, shapedValue);
} else {
llvm_unreachable("expected RankedTensorType or MemRefType");
}
RankedTensorType tensorType = tensor.getType().cast<RankedTensorType>();
SmallVector<Value> dynamicSizes;
if (!copy) {
// Compute the dynamic part of the shape.
// First try to query the shape via ReifyRankedShapedTypeOpInterface.
bool reifiedShapes = false;
if (shapedValue.getType().isa<RankedTensorType>() &&
shapedValue.isa<OpResult>()) {
if (auto rankedOp = dyn_cast_or_null<ReifyRankedShapedTypeOpInterface>(
shapedValue.getDefiningOp())) {
ReifiedRankedShapedTypeDims resultDims;
if (succeeded(rankedOp.reifyResultShapes(b, resultDims))) {
reifiedShapes = true;
auto &shape =
resultDims[shapedValue.cast<OpResult>().getResultNumber()];
for (const auto &dim : enumerate(tensorType.getShape()))
if (ShapedType::isDynamic(dim.value()))
dynamicSizes.push_back(shape[dim.index()]);
}
}
}
// If the shape could not be reified, create DimOps.
if (!reifiedShapes)
populateDynamicDimSizes(b, loc, tensor, dynamicSizes);
}
// Create AllocTensorOp.
auto allocTensorOp = b.create<AllocTensorOp>(loc, tensorType, dynamicSizes,
copy ? tensor : Value());
allocTensorOp->setAttr(BufferizationDialect::kEscapeAttrName,
b.getBoolArrayAttr({escape}));
// Add 'memory_space' attribute. Not needed if 'copy' operand is specified.
if (copy)
return allocTensorOp.getResult();
FailureOr<BaseMemRefType> copyBufferType = getBufferType(tensor, options);
if (failed(copyBufferType))
return failure();
Attribute memorySpace = copyBufferType->getMemorySpace();
if (!memorySpace)
memorySpace = b.getI64IntegerAttr(0);
allocTensorOp.setMemorySpaceAttr(memorySpace);
return allocTensorOp.getResult();
}
LogicalResult BufferizableOpInterface::resolveTensorOpOperandConflicts(
RewriterBase &rewriter, const AnalysisState &state) {
OpBuilder::InsertionGuard g(rewriter);
Operation *op = getOperation();
SmallVector<OpOperand *> outOfPlaceOpOperands;
DenseSet<OpOperand *> copiedOpOperands;
DenseSet<OpOperand *> escapingOpOperandCopies;
SmallVector<OpResult> outOfPlaceOpResults;
DenseSet<OpResult> copiedOpResults;
DenseSet<OpResult> escapingOpResultCopies;
// Find all out-of-place OpOperands.
for (OpOperand &opOperand : op->getOpOperands()) {
Type operandType = opOperand.get().getType();
if (!operandType.isa<TensorType>())
continue;
if (state.isInPlace(opOperand))
continue;
if (operandType.isa<UnrankedTensorType>())
return op->emitError("copies of unranked tensors are not supported");
SmallVector<OpResult> aliasingOpResults =
state.getAliasingOpResult(opOperand);
// Is the result yielded from a block? Or are deallocations turned off
// entirely? In either case, mark the allocation as "escaping", so that it
// will not be deallocated.
bool escape = !state.getOptions().createDeallocs ||
llvm::any_of(aliasingOpResults, [&](Value v) {
return state.isTensorYielded(v);
});
if (aliasingOpResults.size() == 1 &&
!state.bufferizesToMemoryWrite(opOperand) &&
state.getAliasingOpOperand(aliasingOpResults.front()).size() == 1) {
// The op itself does not write but may create exactly one alias. Instead
// of copying the OpOperand, copy the OpResult. The OpResult can sometimes
// be smaller than the OpOperand (e.g., in the case of an extract_slice,
// where the result is usually a smaller part of the source).
outOfPlaceOpResults.push_back(aliasingOpResults.front());
if (!state.canOmitTensorCopy(opOperand))
copiedOpResults.insert(aliasingOpResults.front());
if (escape)
escapingOpResultCopies.insert(aliasingOpResults.front());
} else {
// In all other cases, make a copy of the OpOperand.
outOfPlaceOpOperands.push_back(&opOperand);
if (!state.canOmitTensorCopy(opOperand))
copiedOpOperands.insert(&opOperand);
if (escape)
escapingOpOperandCopies.insert(&opOperand);
}
}
// Insert copies of OpOperands.
rewriter.setInsertionPoint(op);
for (OpOperand *opOperand : outOfPlaceOpOperands) {
FailureOr<Value> copy = allocateTensorForShapedValue(
rewriter, op->getLoc(), opOperand->get(),
escapingOpOperandCopies.contains(opOperand), state.getOptions(),
copiedOpOperands.contains(opOperand));
if (failed(copy))
return failure();
rewriter.updateRootInPlace(op, [&]() { opOperand->set(*copy); });
}
// Insert copies of OpResults.
rewriter.setInsertionPointAfter(op);
for (OpResult opResult : outOfPlaceOpResults) {
FailureOr<Value> copy = allocateTensorForShapedValue(
rewriter, op->getLoc(), opResult,
escapingOpResultCopies.contains(opResult), state.getOptions(),
copiedOpResults.count(opResult));
if (failed(copy))
return failure();
SmallVector<OpOperand *> uses = llvm::to_vector(llvm::map_range(
opResult.getUses(), [](OpOperand &use) { return &use; }));
for (OpOperand *use : uses) {
// Do not update the alloc_tensor op that we just created.
if (use->getOwner() != copy->getDefiningOp())
rewriter.updateRootInPlace(use->getOwner(), [&]() { use->set(*copy); });
}
}
return success();
}
bool bufferization::shouldDeallocateOpResult(
OpResult opResult, const BufferizationOptions &options) {
Operation *op = opResult.getOwner();
assert(options.dynCastBufferizableOp(op).bufferizesToAllocation(opResult) &&
"expected that op allocates");
AnalysisState analysisState(options);
if (op->hasAttr(BufferizationDialect::kEscapeAttrName)) {
// AllocTensorOp has one result.
ArrayAttr escapeAttr =
op->getAttr(BufferizationDialect::kEscapeAttrName).cast<ArrayAttr>();
return !escapeAttr[0].cast<BoolAttr>().getValue();
}
// No "escape" annotation found.
if (options.createDeallocs) {
// Perform an ad-hoc analysis.
return !analysisState.isTensorYielded(opResult);
}
return false;
}
//===----------------------------------------------------------------------===//
// OpFilter
//===----------------------------------------------------------------------===//
bool OpFilter::isOpAllowed(Operation *op) const {
// All other ops: Allow/disallow according to filter.
bool isAllowed = !hasAllowRule();
for (const Entry &entry : entries) {
bool filterResult = entry.fn(op);
switch (entry.type) {
case Entry::ALLOW:
isAllowed |= filterResult;
break;
case Entry::DENY:
if (filterResult)
// DENY filter matches. This op is no allowed. (Even if other ALLOW
// filters may match.)
return false;
};
}
return isAllowed;
}
//===----------------------------------------------------------------------===//
// BufferizationOptions
//===----------------------------------------------------------------------===//
/// Default unknown type converter: Use a fully dynamic layout map.
static BaseMemRefType
defaultUnknownTypeConverter(Value value, Attribute memorySpace,
const BufferizationOptions &options) {
return getMemRefTypeWithFullyDynamicLayout(value.getType().cast<TensorType>(),
memorySpace);
}
// Default constructor for BufferizationOptions.
BufferizationOptions::BufferizationOptions()
: unknownTypeConverterFn(defaultUnknownTypeConverter) {}
bool BufferizationOptions::isOpAllowed(Operation *op) const {
// Special case: If function boundary bufferization is deactivated, do not
// allow ops that belong to the `func` dialect.
bool isFuncBoundaryOp = isa_and_nonnull<func::FuncDialect>(op->getDialect());
if (!bufferizeFunctionBoundaries && isFuncBoundaryOp)
return false;
return opFilter.isOpAllowed(op);
}
BufferizableOpInterface
BufferizationOptions::dynCastBufferizableOp(Operation *op) const {
auto bufferizableOp = dyn_cast<BufferizableOpInterface>(op);
if (!bufferizableOp)
return nullptr;
if (!isOpAllowed(op))
return nullptr;
return bufferizableOp;
}
BufferizableOpInterface
BufferizationOptions::dynCastBufferizableOp(Value value) const {
if (auto bufferizableOp = value.getDefiningOp<BufferizableOpInterface>())
if (isOpAllowed(bufferizableOp.getOperation()))
return bufferizableOp;
return nullptr;
}
//===----------------------------------------------------------------------===//
// Helper functions for BufferizableOpInterface
//===----------------------------------------------------------------------===//
static void setInsertionPointAfter(OpBuilder &b, Value value) {
if (auto bbArg = value.dyn_cast<BlockArgument>()) {
b.setInsertionPointToStart(bbArg.getOwner());
} else {
b.setInsertionPointAfter(value.getDefiningOp());
}
}
/// Determine which OpOperand* will alias with `result` if the op is bufferized
/// in place. Return an empty vector if the op is not bufferizable.
SmallVector<OpOperand *>
AnalysisState::getAliasingOpOperand(OpResult result) const {
if (Operation *op = result.getDefiningOp())
if (auto bufferizableOp = getOptions().dynCastBufferizableOp(op))
return bufferizableOp.getAliasingOpOperand(result, *this);
return {};
}
/// Determine which OpResult will alias with `opOperand` if the op is bufferized
/// in place. Return an empty vector if the op is not bufferizable.
SmallVector<OpResult>
AnalysisState::getAliasingOpResult(OpOperand &opOperand) const {
if (auto bufferizableOp =
getOptions().dynCastBufferizableOp(opOperand.getOwner()))
return bufferizableOp.getAliasingOpResult(opOperand, *this);
return {};
}
/// Return true if `opOperand` bufferizes to a memory read. Return `true` if the
/// op is not bufferizable.
bool AnalysisState::bufferizesToMemoryRead(OpOperand &opOperand) const {
if (auto bufferizableOp =
getOptions().dynCastBufferizableOp(opOperand.getOwner()))
return bufferizableOp.bufferizesToMemoryRead(opOperand, *this);
// Unknown op that returns a tensor. The inplace analysis does not support it.
// Conservatively return true.
return true;
}
/// Return true if `opOperand` bufferizes to a memory write. Return
/// `true` if the op is not bufferizable.
bool AnalysisState::bufferizesToMemoryWrite(OpOperand &opOperand) const {
if (auto bufferizableOp =
getOptions().dynCastBufferizableOp(opOperand.getOwner()))
return bufferizableOp.bufferizesToMemoryWrite(opOperand, *this);
// Unknown op that returns a tensor. The inplace analysis does not support it.
// Conservatively return true.
return true;
}
/// Return true if `opOperand` does neither read nor write but bufferizes to an
/// alias. Return false if the op is not bufferizable.
bool AnalysisState::bufferizesToAliasOnly(OpOperand &opOperand) const {
if (auto bufferizableOp =
getOptions().dynCastBufferizableOp(opOperand.getOwner()))
return bufferizableOp.bufferizesToAliasOnly(opOperand, *this);
// Unknown op that returns a tensor. The inplace analysis does not support it.
// Conservatively return false.
return false;
}
/// Return true if the given value is read by an op that bufferizes to a memory
/// read. Also takes into account ops that create an alias but do not read by
/// themselves (e.g., ExtractSliceOp).
bool AnalysisState::isValueRead(Value value) const {
assert(value.getType().isa<TensorType>() && "expected TensorType");
SmallVector<OpOperand *> workingSet;
for (OpOperand &use : value.getUses())
workingSet.push_back(&use);
while (!workingSet.empty()) {
OpOperand *uMaybeReading = workingSet.pop_back_val();
// Skip over all ops that neither read nor write (but create an alias).
if (bufferizesToAliasOnly(*uMaybeReading))
for (OpResult opResult : getAliasingOpResult(*uMaybeReading))
for (OpOperand &use : opResult.getUses())
workingSet.push_back(&use);
if (bufferizesToMemoryRead(*uMaybeReading))
return true;
}
return false;
}
// Starting from `value`, follow the use-def chain in reverse, always selecting
// the aliasing OpOperands. Find and return Values for which `condition`
// evaluates to true. OpOperands of such matching Values are not traversed any
// further.
llvm::SetVector<Value> AnalysisState::findValueInReverseUseDefChain(
Value value, llvm::function_ref<bool(Value)> condition,
bool followEquivalentOnly) const {
llvm::SetVector<Value> result, workingSet;
workingSet.insert(value);
while (!workingSet.empty()) {
Value value = workingSet.pop_back_val();
if (condition(value) || value.isa<BlockArgument>()) {
result.insert(value);
continue;
}
OpResult opResult = value.cast<OpResult>();
BufferizableOpInterface bufferizableOp =
options.dynCastBufferizableOp(opResult.getDefiningOp());
SmallVector<OpOperand *> opOperands = getAliasingOpOperand(opResult);
// Stop iterating in either one of these cases:
// * The current op is not bufferizable or excluded in the filter.
// * There are no OpOperands to follow.
// * There is an OpOperand, but it is not an equivalent tensor (only if
// `followEquivalentOnly` is set).
if (!bufferizableOp || opOperands.empty() ||
(followEquivalentOnly &&
bufferizableOp.bufferRelation(opResult, *this) !=
BufferRelation::Equivalent)) {
result.insert(value);
continue;
}
for (OpOperand *o : opOperands)
workingSet.insert(o->get());
}
return result;
}
// Find the Values of the last preceding write of a given Value.
llvm::SetVector<Value>
AnalysisState::findLastPrecedingWrite(Value value) const {
return findValueInReverseUseDefChain(value, [&](Value value) {
Operation *op = value.getDefiningOp();
if (!op)
return true;
auto bufferizableOp = options.dynCastBufferizableOp(op);
if (!bufferizableOp)
return true;
return bufferizableOp.isMemoryWrite(value.cast<OpResult>(), *this);
});
}
AnalysisState::AnalysisState(const BufferizationOptions &options)
: AnalysisState(options, TypeID::get<AnalysisState>()) {}
AnalysisState::AnalysisState(const BufferizationOptions &options, TypeID type)
: options(options), type(type) {
for (const BufferizationOptions::AnalysisStateInitFn &fn :
options.stateInitializers)
fn(*this);
}
bool AnalysisState::canOmitTensorCopy(OpOperand &opOperand) const {
// Do not copy if the tensor has undefined contents.
if (hasUndefinedContents(&opOperand))
return true;
// Do not copy if the buffer of the tensor is entirely overwritten (with
// values that do not depend on the old tensor).
if (bufferizesToMemoryWrite(opOperand) && !bufferizesToMemoryRead(opOperand))
return true;
// Do not copy if the tensor is never read.
SmallVector<OpResult> aliasingOpResults = getAliasingOpResult(opOperand);
if (!bufferizesToMemoryRead(opOperand) &&
llvm::none_of(aliasingOpResults,
[&](OpResult opResult) { return isValueRead(opResult); }))
return true;
// Default: Cannot omit the copy.
return false;
}
bool AnalysisState::isInPlace(OpOperand &opOperand) const {
// ToMemrefOps are always in-place.
if (isa<ToMemrefOp>(opOperand.getOwner()))
return true;
// In the absence of analysis information, OpOperands that bufferize to a
// memory write are out-of-place, i.e., an alloc and copy is inserted.
return !bufferizesToMemoryWrite(opOperand);
}
bool AnalysisState::areEquivalentBufferizedValues(Value v1, Value v2) const {
// In the absence of analysis information, we do not know if the values are
// equivalent. The conservative answer is "false".
return false;
}
bool AnalysisState::areAliasingBufferizedValues(Value v1, Value v2) const {
// In the absence of analysis information, we do not know if the values may be
// aliasing. The conservative answer is "true".
return true;
}
bool AnalysisState::hasUndefinedContents(OpOperand *opOperand) const {
// In the absence of analysis information, the conservative answer is "false".
return false;
}
bool AnalysisState::isTensorYielded(Value tensor) const {
// In the absence of analysis information, the conservative answer is "true".
if (!tensor.getDefiningOp<AllocTensorOp>())
return true;
// For AllocTensorOp results, we can do better: They do not alias with any
// preceding value, so we can follow SSA use-def chains and do a simple
// analysis.
SmallVector<OpOperand *> worklist;
for (OpOperand &use : tensor.getUses())
worklist.push_back(&use);
while (!worklist.empty()) {
OpOperand *operand = worklist.pop_back_val();
Operation *op = operand->getOwner();
// If the op is not bufferizable, we can safely assume that the value is not
// yielded. (When bufferizing that op, it must handle such cases.)
if (!options.dynCastBufferizableOp(op))
continue;
// We cannot analyze through ToMemrefOps, so we have to conservatively
// assume that the value is yielded.
if (isa<ToMemrefOp>(op))
return true;
// Check if the op is returning/yielding.
if (isRegionReturnLike(op))
return true;
// Add all aliasing OpResults to the worklist.
// Note: In the absence of detailed analysis information (e.g., there may be
// no function call analysis information), this `getAliasingOpResult` is
// conservative and may report additional OpResults as potentially aliasing.
for (OpResult opResult : getAliasingOpResult(*operand))
for (OpOperand &use : opResult.getUses())
worklist.push_back(&use);
}
// No ReturnLike op found: The value is not yielded.
return false;
}
// bufferization.to_memref is not allowed to change the rank.
static void ensureToMemrefOpIsValid(Value tensor, Type memrefType) {
#ifndef NDEBUG
auto rankedTensorType = tensor.getType().dyn_cast<RankedTensorType>();
assert((!rankedTensorType || memrefType.cast<MemRefType>().getRank() ==
rankedTensorType.getRank()) &&
"to_memref would be invalid: mismatching ranks");
#endif
}
FailureOr<Value> bufferization::getBuffer(RewriterBase &rewriter, Value value,
const BufferizationOptions &options) {
#ifndef NDEBUG
auto tensorType = value.getType().dyn_cast<TensorType>();
assert(tensorType && "unexpected non-tensor type");
#endif // NDEBUG
// Replace "%t = to_tensor %m" with %m.
if (auto toTensorOp = value.getDefiningOp<bufferization::ToTensorOp>())
return toTensorOp.getMemref();
// Insert to_memref op.
OpBuilder::InsertionGuard g(rewriter);
setInsertionPointAfter(rewriter, value);
FailureOr<BaseMemRefType> memrefType = getBufferType(value, options);
if (failed(memrefType))
return failure();
ensureToMemrefOpIsValid(value, *memrefType);
return rewriter
.create<bufferization::ToMemrefOp>(value.getLoc(), *memrefType, value)
.getResult();
}
FailureOr<BaseMemRefType> bufferization::detail::defaultGetBufferType(
Value value, const BufferizationOptions &options,
const DenseMap<Value, BaseMemRefType> &fixedTypes) {
assert(value.getType().isa<TensorType>() && "expected tensor type");
// No further analysis is possible for a block argument.
if (value.isa<BlockArgument>())
return bufferization::getMemRefType(value, options);
// Value is an OpResult.
Operation *op = getOwnerOfValue(value);
auto opResult = value.cast<OpResult>();
auto bufferizableOp = cast<BufferizableOpInterface>(op);
AnalysisState state(options);
auto aliasingOperands = bufferizableOp.getAliasingOpOperand(opResult, state);
if (!aliasingOperands.empty() &&
bufferizableOp.bufferRelation(opResult, state) ==
BufferRelation::Equivalent) {
// If the OpResult has an equivalent OpOperand, both OpResult and
// OpOperand bufferize to the exact same buffer type.
Value equivalentOperand = aliasingOperands.front()->get();
return getBufferType(equivalentOperand, options, fixedTypes);
}
// If we do not know the memory space and there is no default memory space,
// report a failure.
if (!options.defaultMemorySpace.has_value())
return op->emitError("could not infer memory space");
return getMemRefType(value, options, /*layout=*/{},
*options.defaultMemorySpace);
}
/// Return the buffer type for a given Value (tensor) after bufferization.
FailureOr<BaseMemRefType>
bufferization::getBufferType(Value value, const BufferizationOptions &options) {
DenseMap<Value, BaseMemRefType> fixedTypes;
return getBufferType(value, options, fixedTypes);
}
/// Return the buffer type for a given Value (tensor) after bufferization.
FailureOr<BaseMemRefType> bufferization::getBufferType(
Value value, const BufferizationOptions &options,
const DenseMap<Value, BaseMemRefType> &fixedTypes) {
assert(value.getType().isa<TensorType>() && "unexpected non-tensor type");
// If the `value` is in `fixedTypes`, return the mapped type.
const auto &it = fixedTypes.find(value);
if (it != fixedTypes.end())
return it->second;
// Try querying BufferizableOpInterface.
Operation *op = getOwnerOfValue(value);
auto bufferizableOp = options.dynCastBufferizableOp(op);
if (bufferizableOp)
return bufferizableOp.getBufferType(value, options, fixedTypes);
// Op is not bufferizable.
if (!options.defaultMemorySpace.has_value())
return op->emitError("could not infer memory space");
return getMemRefType(value, options, /*layout=*/{},
*options.defaultMemorySpace);
}
void bufferization::replaceOpWithBufferizedValues(RewriterBase &rewriter,
Operation *op,
ValueRange values) {
assert(values.size() == op->getNumResults() &&
"expected one value per OpResult");
OpBuilder::InsertionGuard g(rewriter);
// Replace all OpResults with the given values.
SmallVector<Value> replacements;
for (OpResult opResult : op->getOpResults()) {
Value replacement = values[opResult.getResultNumber()];
if (opResult.getType().isa<TensorType>()) {
// The OpResult is a tensor. Such values are replaced with memrefs during
// bufferization.
assert((replacement.getType().isa<MemRefType>() ||
replacement.getType().isa<UnrankedMemRefType>()) &&
"tensor op result should be replaced with a memref value");
// The existing uses of the OpResult still expect a tensor. Insert a
// ToTensorOp. Throughout bufferization, this ToTensorOp will gradually
// loose all of its users and eventually DCE away.
rewriter.setInsertionPointAfter(op);
replacement = rewriter.create<bufferization::ToTensorOp>(
replacement.getLoc(), replacement);
}
replacements.push_back(replacement);
}
rewriter.replaceOp(op, replacements);
}
//===----------------------------------------------------------------------===//
// Bufferization-specific scoped alloc/dealloc insertion support.
//===----------------------------------------------------------------------===//
/// Create a memref allocation with the given type and dynamic extents.
FailureOr<Value> BufferizationOptions::createAlloc(OpBuilder &b, Location loc,
MemRefType type,
ValueRange dynShape) const {
if (allocationFn)
return (*allocationFn)(b, loc, type, dynShape, bufferAlignment);
// Default bufferallocation via AllocOp.
if (bufferAlignment != 0)
return b
.create<memref::AllocOp>(loc, type, dynShape,
b.getI64IntegerAttr(bufferAlignment))
.getResult();
return b.create<memref::AllocOp>(loc, type, dynShape).getResult();
}
/// Creates a memref deallocation. The given memref buffer must have been
/// allocated using `createAlloc`.
LogicalResult BufferizationOptions::createDealloc(OpBuilder &b, Location loc,
Value allocatedBuffer) const {
if (deallocationFn)
return (*deallocationFn)(b, loc, allocatedBuffer);
// Default buffer deallocation via DeallocOp.
b.create<memref::DeallocOp>(loc, allocatedBuffer);
return success();
}
/// Create a memory copy between two memref buffers.
LogicalResult BufferizationOptions::createMemCpy(OpBuilder &b, Location loc,
Value from, Value to) const {
if (memCpyFn)
return (*memCpyFn)(b, loc, from, to);
b.create<memref::CopyOp>(loc, from, to);
return success();
}
//===----------------------------------------------------------------------===//
// Bufferization-specific BlockAndValueMapping support with debugging.
//===----------------------------------------------------------------------===//
bool bufferization::isFunctionArgument(Value value) {
auto bbArg = value.dyn_cast<BlockArgument>();
if (!bbArg)
return false;
return isa<func::FuncOp>(bbArg.getOwner()->getParentOp());
}
BaseMemRefType bufferization::getMemRefType(Value value,
const BufferizationOptions &options,
MemRefLayoutAttrInterface layout,
Attribute memorySpace) {
auto tensorType = value.getType().cast<TensorType>();
// Case 1: Unranked memref type.
if (auto unrankedTensorType = tensorType.dyn_cast<UnrankedTensorType>()) {
assert(!layout && "UnrankedTensorType cannot have a layout map");
return UnrankedMemRefType::get(unrankedTensorType.getElementType(),
memorySpace);
}
// Case 2: Ranked memref type with specified layout.
auto rankedTensorType = tensorType.cast<RankedTensorType>();
if (layout) {
return MemRefType::get(rankedTensorType.getShape(),
rankedTensorType.getElementType(), layout,
memorySpace);
}
return options.unknownTypeConverterFn(value, memorySpace, options);
}
BaseMemRefType
bufferization::getMemRefTypeWithFullyDynamicLayout(TensorType tensorType,
Attribute memorySpace) {
// Case 1: Unranked memref type.
if (auto unrankedTensorType = tensorType.dyn_cast<UnrankedTensorType>()) {
return UnrankedMemRefType::get(unrankedTensorType.getElementType(),
memorySpace);
}
// Case 2: Ranked memref type.
auto rankedTensorType = tensorType.cast<RankedTensorType>();
int64_t dynamicOffset = ShapedType::kDynamic;
SmallVector<int64_t> dynamicStrides(rankedTensorType.getRank(),
ShapedType::kDynamic);
auto stridedLayout = StridedLayoutAttr::get(tensorType.getContext(),
dynamicOffset, dynamicStrides);
return MemRefType::get(rankedTensorType.getShape(),
rankedTensorType.getElementType(), stridedLayout,
memorySpace);
}
/// Return a MemRef type with a static identity layout (i.e., no layout map). If
/// the given tensor type is unranked, return an unranked MemRef type.
BaseMemRefType
bufferization::getMemRefTypeWithStaticIdentityLayout(TensorType tensorType,
Attribute memorySpace) {
// Case 1: Unranked memref type.
if (auto unrankedTensorType = tensorType.dyn_cast<UnrankedTensorType>()) {
return UnrankedMemRefType::get(unrankedTensorType.getElementType(),
memorySpace);
}
// Case 2: Ranked memref type.
auto rankedTensorType = tensorType.cast<RankedTensorType>();
MemRefLayoutAttrInterface layout = {};
return MemRefType::get(rankedTensorType.getShape(),
rankedTensorType.getElementType(), layout,
memorySpace);
}
bool bufferization::detail::defaultIsRepetitiveRegion(
BufferizableOpInterface bufferizableOp, unsigned index) {
assert(index < bufferizableOp->getNumRegions() && "invalid region index");
auto regionInterface =
dyn_cast<RegionBranchOpInterface>(bufferizableOp.getOperation());
if (!regionInterface)
return false;
return regionInterface.isRepetitiveRegion(index);
}