Files
pytorch/torch/csrc/jit/passes/tensorexpr_fuser.cpp
Yuanyuan Chen 9fff8155c3 [2/N] Fix clang-tidy readability checks (#164652)
This PR applies clang-tidy readability checks to jit sources and all headers in the code base.
`readability-redundant-inline-specifier` is suppressed because it incurs too many changes. `readability-redundant-inline-specifier` is used to detect redundant inline specifiers on function and variable declarations. There are many in-class method definitions that are marked inline.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/164652
Approved by: https://github.com/Skylion007
2025-10-06 01:06:01 +00:00

1456 lines
50 KiB
C++

#include <torch/csrc/jit/passes/tensorexpr_fuser.h>
#include <ATen/core/interned_strings.h>
#include <ATen/core/symbol.h>
#include <ATen/record_function.h>
#include <c10/util/FunctionRef.h>
#include <c10/util/irange.h>
#include <torch/csrc/jit/codegen/cuda/interface.h>
#include <torch/csrc/jit/codegen/fuser/interface.h>
#include <torch/csrc/jit/ir/alias_analysis.h>
#include <torch/csrc/jit/jit_log.h>
#include <torch/csrc/jit/jit_opt_limit.h>
#include <torch/csrc/jit/passes/common_subexpression_elimination.h>
#include <torch/csrc/jit/passes/constant_pooling.h>
#include <torch/csrc/jit/passes/dead_code_elimination.h>
#include <torch/csrc/jit/passes/pass_manager.h>
#include <torch/csrc/jit/passes/remove_redundant_profiles.h>
#include <torch/csrc/jit/passes/symbolic_shape_runtime_fusion.h>
#include <torch/csrc/jit/passes/utils/subgraph_utils.h>
#include <torch/csrc/jit/runtime/custom_operator.h>
#include <torch/csrc/jit/runtime/graph_executor.h>
#include <torch/csrc/jit/runtime/operator_options.h>
#include <torch/csrc/jit/runtime/symbolic_shape_registry.h>
#include <torch/csrc/jit/runtime/symbolic_shape_registry_util.h>
#include <torch/csrc/jit/tensorexpr/kernel.h>
#include <utility>
// clang-format off
C10_DEFINE_bool(
torch_jit_disable_cat,
false,
"disable aten::cat in TE fusion groups")
C10_DEFINE_bool(
torch_jit_enable_dynamic_shape_fusion,
false,
"enable TE fusion using dynamic shapes")
namespace torch::jit {
static bool texpr_reductions_enabled = false;
static bool isSupportedForBlock(Node* node) {
switch (node->kind()) {
case aten::add:
case aten::mul:
return true;
default:
return false;
}
}
bool usedOnlyInSize(Value* v) {
const auto& uses = v->uses();
return std::all_of(uses.begin(), uses.end(), [](const Use& u) {
return u.user->matches("aten::size(Tensor self) -> int[]");
});
}
Value* broadcastSizes(at::ArrayRef<Value*> sizes, AliasDb* db) {
AT_ASSERT(!sizes.empty());
Graph* graph = sizes[0]->owningGraph();
Node* broadcast_n =
graph->insertNode(graph->create(prim::BroadcastSizes, sizes));
broadcast_n->output()->setType(ListType::ofInts());
db->createValue(broadcast_n->output());
return broadcast_n->output();
}
namespace tensorexpr {
OperatorSet& getCustomOperatorSet() {
static OperatorSet _g_custom_operator_set{};
return _g_custom_operator_set;
}
static const OperatorSet& supported_non_eltwise_set() {
// clang-format off
static const OperatorSet supported_non_eltwise_set{
"aten::batch_norm(Tensor input, Tensor? weight, Tensor? bias, Tensor? running_mean, Tensor? running_var, bool training, float momentum, float eps, bool cudnn_enabled) -> Tensor",
"aten::conv2d(Tensor input, Tensor weight, Tensor? bias=None, int[2] stride=1, int[2] padding=0, int[2] dilation=1, int groups=1) -> Tensor",
"aten::_convolution(Tensor input, Tensor weight, Tensor? bias, int[] stride, int[] padding, int[] dilation, bool transposed, int[] output_padding, int groups, bool benchmark, bool deterministic, bool cudnn_enabled, bool allow_tf32) -> Tensor",
"aten::matmul(Tensor self, Tensor other) -> Tensor",
};
return supported_non_eltwise_set;
}
bool isSupported(Node* node) {
// For Block codegen we allow limited ops.
if (tensorexpr::getTEGenerateBlockCode()) {
return isSupportedForBlock(node);
}
static const OperatorSet supported_reduction_set{
"aten::sum(Tensor self, *, ScalarType? dtype=None) -> Tensor",
"aten::sum.dim_IntList(Tensor self, int[1]? dim, bool keepdim=False, *, ScalarType? dtype=None) -> Tensor",
"aten::softmax.int(Tensor self, int dim , ScalarType? dtype=None) -> Tensor",
"aten::log_softmax.int(Tensor self, int dim, ScalarType? dtype=None) -> Tensor",
};
static const OperatorSet supported_misc_set{
"aten::cat(Tensor[] tensors, int dim=0) -> Tensor",
"aten::unsqueeze(Tensor(a) self, int dim) -> Tensor(a)",
};
if (get_tensorexpr_elementwise_set().contains(node) ||
node->isMemberOf(supported_non_eltwise_set()) ||
node->isMemberOf(supported_misc_set) ||
node->isMemberOf(getCustomOperatorSet()) ||
(texpr_reductions_enabled && node->isMemberOf(supported_reduction_set))) {
// We only insert guards on Tensor types, so we rely on the output
// of a node being uniquely determined by its input types.
// bail if any non-Tensor input affects the output type
// and cannot be reasoned about statically
// Value is either an int or a float (can occur from .item())
for (Value* v : node->inputs()) {
if (v->type()->cast<NumberType>()) {
return false;
}
}
// non-const dtype / device
for (auto arg_name : {"dtype", "device"}) {
if (auto index = node->schema().argumentIndexWithName(arg_name)) {
if (!toIValue(node->input(*index))) {
return false;
}
}
}
if (FLAGS_torch_jit_disable_cat && node->kind() == aten::cat) {
return false;
}
return true;
}
// unschematized ops
switch (node->kind()) {
case prim::ConstantChunk:
case prim::ListConstruct:
case prim::TensorExprGroup:
return true;
}
return false;
}
} // namespace tensorexpr
static bool texpr_fuser_enabled_ = true;
void setTensorExprFuserEnabled(bool val) {
texpr_fuser_enabled_ = val;
}
bool tensorExprFuserEnabled() {
static const auto enable_opt = c10::utils::get_env("PYTORCH_TENSOREXPR");
if (!enable_opt.has_value()) {
return texpr_fuser_enabled_;
}
if (enable_opt == "0") {
return false;
}
return true;
}
bool tensorExprDynamicShapeFusionEnabled() {
return FLAGS_torch_jit_enable_dynamic_shape_fusion;
}
void setTensorExprDynamicShapeFusionEnabled(bool val) {
FLAGS_torch_jit_enable_dynamic_shape_fusion = val;
}
bool setTexprReductionsEnabled(bool value) {
bool old_value = texpr_reductions_enabled;
texpr_reductions_enabled = value;
return old_value;
}
bool texprReductionsEnabled() {
return texpr_reductions_enabled;
}
static void removeProfileNodesAndSpecializeTypes(Block* b) {
for (auto it = b->nodes().begin(); it != b->nodes().end(); it++) {
if (it->kind() == prim::profile) {
GRAPH_DEBUG("Removing prim::profile: %", it->output()->debugName());
it->output()->replaceAllUsesWith(it->input());
auto profiled_type = it->ty(attr::profiled_type)->expect<TensorType>();
TensorTypePtr input_tensor_type = nullptr;
bool input_is_optional = false;
if (it->input()->type()->kind() == c10::TypeKind::TensorType) {
input_tensor_type = it->input()->type()->expect<TensorType>();
} else {
auto element_type = it->input()
->type();
if (element_type->cast<OptionalType>()) {
input_tensor_type = element_type->expectRef<OptionalType>()
.getElementType()
->expect<TensorType>();
} else {
// This handles the following scenario:
// 1. profiling nodes are inserted
// 2. optimizations simplify a Tensor? -> None type
// 3. Now the input to the prim::profile() is actually a None type.
element_type->expect<NoneType>();
}
input_is_optional = true;
}
if (input_is_optional) {
it.destroyCurrent();
continue;
}
// A value can be profiled with differently typed uses.
// This can occur from:
// - having a use which is not executed, so the type will be
// TensorType::get()
// - control-flow that depends on tensor type:
// if x.size() == 2 op(x) else op(x)
// - mutation of the value on a field represented in the tensor type
// op(x); x.resize_([...]); op(x)
// The most common case today with num_profiles = 1 is from the first
// case. Here we can just ignore non-profiled uses, and choose any of the
// profiled uses. Because we guard all tensor types in the runtime, even
// if we set a Value to have a profiled type from one use and then execute
// a use with a different profiled type, we will still be correct.
// In the future we could consider unifying the types of uses, or adding a
// type refinement node so uses can have the correct corresponding type.
if (profiled_type == TensorType::get()) {
continue;
}
// If we encounter non-identical profiled types for the same value, merge
// them. This situation can happen if, e.g., loop unrolling duplicates
// profiled types in a loop body in a manner that isn't logically
// consistent (see TestTEFuser.test_unrolled_cat).
if (input_tensor_type == TensorType::get()) {
it->input()->setType(profiled_type);
} else {
it->input()->setType(input_tensor_type->merge(*profiled_type));
}
it.destroyCurrent();
} else {
for (Block* ib : it->blocks()) {
removeProfileNodesAndSpecializeTypes(ib);
}
}
}
}
void RemoveProfileNodesAndSpecializeTypes(std::shared_ptr<Graph>& graph) {
GRAPH_DEBUG("Before removeProfileNodesAndSpecializeTypes:\n", *graph);
removeProfileNodesAndSpecializeTypes(graph->block());
GRAPH_DEBUG("After removeProfileNodesAndSpecializeTypes:\n", *graph);
}
bool hasTensorTypeSpecialization(Value* v) {
if (!v->type()->cast<TensorType>()) {
return false;
}
// Constants & TensorExprGroup will always produce specialized tensor type,
// TypeCheck are inserted by this pass and only used by fusion groups that
// insert proper guards
if (v->node()->kind() == prim::Constant ||
v->node()->kind() == prim::TypeCheck ||
v->node()->kind() == prim::TensorExprGroup) {
return false;
}
if (v->type() == TensorType::get()) {
return false;
}
return true;
}
static void removeTensorTypeSpecialization(Value* v) {
if (hasTensorTypeSpecialization(v)) {
v->setType(TensorType::get());
}
}
void removeTensorTypeSpecializations(Block* block) {
for (Value* v : block->inputs()) {
removeTensorTypeSpecialization(v);
}
for (Node* n : block->nodes()) {
for (Block* b : n->blocks()) {
removeTensorTypeSpecializations(b);
}
for (Value* v : n->outputs()) {
removeTensorTypeSpecialization(v);
}
}
}
void RemoveTensorTypeSpecializations(std::shared_ptr<Graph>& graph) {
removeTensorTypeSpecializations(graph->block());
}
void insertTypeGuard(
Node* guarded_node,
tensor_type_converter_t type_converter,
Symbol kind) {
GRAPH_DEBUG("Inserting a typecheck guard for a node", *guarded_node);
auto subgraph = SubgraphUtils::getSubgraph(guarded_node);
// Fixup types of the subgraph inputs
std::vector<Value*> inputs_to_check;
std::vector<TypePtr> guard_types;
for (Value* input : guarded_node->inputs()) {
// We only check inputs of the guarded nodes and expect user to infer
// intermediates and outputs shapes
if (!input->type()->cast<TensorType>()) {
continue;
}
// fusion outputs are already guarded
if (input->node()->kind() == prim::Constant ||
input->node()->kind() == prim::FusionGroup) {
continue;
}
inputs_to_check.push_back(input);
guard_types.emplace_back(
type_converter(input->type()->expect<TensorType>()));
}
if (inputs_to_check.empty()) {
return;
}
// Add prim::TypeCheck node
//
// TypeCheck nodes look like the following:
// %out1 : Float(2, 3), %out2 : Int(10, 30), %types_match : bool =
// prim::TypeCheck(%inp1 : Tensor, %inp2 : Tensor)
//
// They have N inputs whose types we are going to check and N+1 outputs. The
// first N outputs specify expected types and N+1-th output holds the result
// of the check (bool).
Node* typecheck_node =
guarded_node->owningGraph()
->create(kind, inputs_to_check, inputs_to_check.size() + 1)
->insertBefore(guarded_node);
typecheck_node->tys_(attr::types, std::move(guard_types));
Value* typecheck_result = typecheck_node->output(inputs_to_check.size());
std::unordered_map<Value*, Value*> typechecked_inputs;
for (size_t i = 0; i < typecheck_node->inputs().size(); ++i) {
typechecked_inputs[typecheck_node->input(i)] = typecheck_node->output(i);
}
// Fixup types of the typecheck node outputs, which are used by the op in
// execution
typecheck_node->output(inputs_to_check.size())->setType(BoolType::get());
for (size_t i = 0; i < typecheck_node->inputs().size(); ++i) {
typecheck_node->output(i)->setType(typecheck_node->input(i)->type());
}
// Insert if
auto versioning_if =
guarded_node->owningGraph()
->create(prim::If, {typecheck_result}, guarded_node->outputs().size())
->insertAfter(typecheck_node);
for (size_t idx = 0; idx < guarded_node->outputs().size(); ++idx) {
versioning_if->output(idx)->setType(guarded_node->output(idx)->type());
guarded_node->output(idx)->replaceAllUsesWith(versioning_if->output(idx));
}
auto true_block = versioning_if->addBlock();
auto false_block = versioning_if->addBlock();
// Fill in the false block. It should contain the unoptimized
// copy of the fused subgraph.
WithInsertPoint guard(false_block->return_node());
const auto subgraph_outputs = insertGraph(
*guarded_node->owningGraph(), *subgraph, guarded_node->inputs());
for (Value* output : subgraph_outputs) {
false_block->registerOutput(output);
}
// types get copied to the fallback graph, so remove specializations before
// replacing
removeTensorTypeSpecializations(false_block);
replaceBlockWithFallbackGraph(false_block, guarded_node->inputs());
// Fill in the true block. It has all inputs type-checked and its
// body should be the fusion group node.
guarded_node->moveBefore(true_block->return_node());
for (size_t idx = 0; idx < guarded_node->inputs().size(); ++idx) {
if (typechecked_inputs.count(guarded_node->input(idx))) {
guarded_node->replaceInput(
idx, typechecked_inputs.at(guarded_node->input(idx)));
}
}
for (Value* output : guarded_node->outputs()) {
true_block->registerOutput(output);
}
}
namespace {
bool has_unsupported_pin_memory(const Node* node) {
// can't support non-constant pin_memory or pin_memory = True
if (auto maybe_index = node->schema().argumentIndexWithName("pin_memory")) {
int index = *maybe_index;
auto inp = node->input(index);
if (inp->type() != NoneType::get() &&
constant_as<bool>(inp).value_or(true)) {
return true;
}
}
return false;
}
} // namespace
class TensorExprFuser {
public:
TensorExprFuser(
std::shared_ptr<Graph> graph,
size_t min_group_size,
bool add_composed_op,
bool fuse_to_dynamic_shapes)
: graph_(std::move(graph)),
min_group_size_(min_group_size),
add_composed_op_(add_composed_op),
fuse_to_dynamic_shapes_(fuse_to_dynamic_shapes) {
parseTENotFuseOption();
}
// Builds up expressions that compute shapes of all intermediates (and
// outputs) of the fusion group, based on the sizes of inputs. You should run
// DCE to remove those that you end up not using.
std::unordered_map<Value*, Value*> buildShapeExpressions(Node* fusion_group) {
GRAPH_DUMP("buildShapeExpressions for ", fusion_group->g(attr::Subgraph));
WithInsertPoint insert_guard{fusion_group->next()};
std::unordered_map<Value*, Value*> shape_of;
Graph* graph = fusion_group->owningGraph();
auto subgraph = fusion_group->g(attr::Subgraph);
auto inputs = fusion_group->inputs();
auto sinputs = subgraph->inputs();
AT_ASSERT(inputs.size() == sinputs.size());
for (const auto i : c10::irange(inputs.size())) {
if (inputs[i]->type()->isSubtypeOf(*TensorType::get())) {
Value* soutput = graph->insert(aten::size, {inputs[i]});
aliasDb_->createValue(soutput);
GRAPH_DEBUG(
"Adding a mapping for %",
sinputs[i]->debugName(),
" ",
getHeader(soutput->node()));
shape_of[sinputs[i]] = soutput;
}
}
// When we have a guarantee that an output won't be removed, because it's
// used in expressions that don't involve size checks, we can use its size
// instead of computing a long chain of broadcasts, starting from the
// beginning of the kernel.
auto outputs = fusion_group->outputs();
auto soutputs = subgraph->outputs();
AT_ASSERT(outputs.size() == soutputs.size());
for (const auto i : c10::irange(outputs.size())) {
if (usedOnlyInSize(outputs[i]))
continue;
Value* soutput = graph->insert(aten::size, {outputs[i]});
aliasDb_->createValue(soutput);
shape_of[soutputs[i]] = soutput;
}
for (Node* n : subgraph->nodes()) {
auto tensor_inputs = filter(n->inputs(), [](Value* v) {
return v->type()->isSubtypeOf(*TensorType::get());
});
GRAPH_DEBUG("Building sizes for ", getHeader(n));
bool all_inputs_have_sizes = true;
auto shapes = fmap(tensor_inputs, [&](Value* v) {
GRAPH_DEBUG("Getting aten::size for %", v->debugName());
all_inputs_have_sizes &= shape_of.count(v);
return shape_of.count(v) != 0 ? shape_of.at(v) : nullptr;
});
if (!all_inputs_have_sizes) {
GRAPH_DEBUG(
"Not all tensor arguments have sizes available to compute the broadcasted size",
getHeader(n));
continue;
}
if (n->kind() == prim::ConstantChunk) {
Node* sizes_node = graph->insertNode(
graph->create(prim::ChunkSizes, shape_of.at(n->input()), 2));
sizes_node->i_(attr::dim, n->i(attr::dim));
sizes_node->i_(attr::chunks, n->i(attr::chunks));
for (Value* output : sizes_node->outputs()) {
aliasDb_->createValue(output);
}
Value* regular_size = sizes_node->outputs().at(0);
Value* last_size = sizes_node->outputs().at(1);
regular_size->setType(ListType::ofInts());
last_size->setType(ListType::ofInts());
auto outputs = n->outputs();
for (Value* o : outputs.slice(0, outputs.size() - 1)) {
shape_of.emplace(o, regular_size);
}
shape_of.emplace(outputs.at(outputs.size() - 1), last_size);
continue;
}
// we only support shape calculations for elementwise, some
// non-elementwise like batch_norm, conv, matmul, and
// a few exceptions (e.g. prim::ConstantChunk, etc) listed above
if (!(get_tensorexpr_elementwise_set().contains(n)) &&
!n->isMemberOf(tensorexpr::supported_non_eltwise_set())) {
continue;
}
shape_of.emplace(
n->output(),
shapes.size() == 1 ? shapes[0]
: broadcastSizes(shapes, aliasDb_.get()));
}
return shape_of;
}
void removeOutputsUsedOnlyInSize(Node* fusion_group) {
if (fusion_group->kind() != prim::TensorExprGroup)
return;
auto subgraph = fusion_group->g(attr::Subgraph);
auto shape_of = buildShapeExpressions(fusion_group);
auto outputs = fusion_group->outputs().vec();
auto soutputs = subgraph->outputs().vec();
// XXX: Iterating in this order is not only good for performance reasons!
// It is also crucial for correctness (i has to reflect the current true
// index of outputs[i])!
for (int64_t i = static_cast<int64_t>(outputs.size()) - 1; i >= 0; --i) {
auto output = outputs[i];
auto soutput = soutputs[i];
if (usedOnlyInSize(output) && shape_of.count(soutput) > 0) {
auto uses = output->uses();
for (Use u : uses) {
AT_ASSERT(u.user->matches("aten::size(Tensor self) -> int[]"));
u.user->output()->replaceAllUsesWith(shape_of.at(soutput));
u.user->destroy();
}
fusion_group->eraseOutput(i);
subgraph->eraseOutput(i);
}
}
}
void run() {
aliasDb_ = std::make_unique<AliasDb>(graph_);
RemoveRedundantProfiles(graph_);
GRAPH_DUMP("After removing redundant profile nodes: ", graph_);
createFusionGroups(graph_->block());
GRAPH_DUMP("After creating fusion groups: ", graph_);
// we maintain alias db correctness during initial fusion, but it is
// difficult to maintain correctness after inlining so inline only after
// fusion is done.
inlineSmallFusionGroups(graph_->block());
GRAPH_DUMP("After inlining small fusion groups: ", graph_);
if (fuse_to_dynamic_shapes_) {
VLOG(1) << "TensorExpr fusion with dynamic shapes is enabled" << '\n';
generalizeFusionGroups(graph_->block());
GRAPH_DUMP("After generalizing fusion groups: ", graph_);
} else {
prepareFusionGroupAndGuardOutputs(graph_->block());
GRAPH_DUMP("After guarding fusion groups: ", graph_);
}
}
private:
Node* getOrCreateTensorExprSubgraph(Node* n) {
if (n->hasAttribute(attr::Subgraph) && n->kind() == prim::TensorExprGroup) {
return n;
}
GRAPH_UPDATE("Creating a tensorexpr::Group node from: ", *n);
return SubgraphUtils::createSingletonSubgraphAndUpdateAliasing(
n, prim::TensorExprGroup, *aliasDb_);
}
value_list sortReverseTopological(ArrayRef<Value*> inputs, Block* b) {
value_list result;
for (auto i : inputs) {
if (i->node()->owningBlock() == b) {
result.push_back(i);
}
}
// Sort in reverse topological order
std::sort(result.begin(), result.end(), [&](Value* a, Value* b) {
return a->node()->isAfter(b->node());
});
return result;
}
// Create a fusion group starting from the node N.
// We then try to pull inputs into the fusion group and repeat that process
// until there is nothing we can pull in.
std::pair<graph_node_list::iterator, bool> createFusionGroup(
Node* fusion_node) {
// Allow single-node groups containing conv2d, since we'll only select
// those in cases where the tensorexpr implementation is faster than the
// aten implementation.
if (min_group_size_ == 1 || fusion_node->kind() == aten::conv2d) {
fusion_node = getOrCreateTensorExprSubgraph(fusion_node);
}
GRAPH_DEBUG("Iteratively pull input nodes into the fusion group...\n");
auto inputs = sortReverseTopological(
fusion_node->inputs(), fusion_node->owningBlock());
for (auto input : inputs) {
debugDumpFusionGroup("Current fusion group: ", fusion_node);
GRAPH_DEBUG("Trying to merge: ", *input->node());
if (auto maybe_fusion_group = tryMerge(fusion_node, input->node())) {
// we successfully merged, so the new group's `inputs` may have
// changed. So rescan the new group for more merging opportunities.
return std::make_pair(
maybe_fusion_group.value()->reverseIterator(), true);
}
}
return std::make_pair(++fusion_node->reverseIterator(), false);
}
static void debugDumpFusionGroup(const std::string& msg, Node* n) {
GRAPH_DEBUG(msg, *n);
if (n->kind() == prim::TensorExprGroup) {
GRAPH_DEBUG(*n->g(attr::Subgraph));
}
}
// No Ops in eager shouldn't be outputs of Fusion Groups because it
// will degrade perf and change aliasing relationships
static bool unexecutedEagerOp(Node* n) {
if (n->kind() != aten::to &&
n->kind() != aten::_autocast_to_reduced_precision &&
n->kind() != aten::_autocast_to_full_precision) {
return false;
}
return *n->input(0)->type()->expect<TensorType>() ==
*n->output()->type()->expect<TensorType>();
}
std::pair<graph_node_list::iterator, bool> scanNode(Node* n) {
GRAPH_DEBUG("Considering node:", *n)
if (!canHandle(n)) {
return std::make_pair(++n->reverseIterator(), false);
}
// There are some nodes that we can support, but we don't want to start a
// fusion group from - skip them.
if (n->kind() == prim::ListConstruct || n->kind() == aten::slice ||
n->kind() == aten::unsqueeze || n->kind() == prim::ConstantChunk ||
n->kind() == prim::Constant || unexecutedEagerOp(n)) {
return std::make_pair(++n->reverseIterator(), false);
}
return createFusionGroup(n);
}
// Merge fusible nodes into subgraphs in prim::TensorExprGroup nodes.
void createFusionGroups(Block* block) {
bool any_changed = true;
while (any_changed) {
any_changed = false;
for (auto it = block->nodes().rbegin(); it != block->nodes().rend();) {
auto [tmp_it, changed] = scanNode(*it);
it = tmp_it;
any_changed |= changed;
}
}
for (Node* n : block->nodes()) {
for (Block* b : n->blocks()) {
createFusionGroups(b);
}
}
// Try to merge adjacent fusion groups together. Because we have only merged
// by looking at graph inputs, without this we would not attempt to merge
// adjacent fusion groups that don't have a dependency on each other
std::vector<Node*> initial_fusion_groups;
for (Node* n : block->nodes()) {
if (n->kind() == prim::TensorExprGroup) {
initial_fusion_groups.push_back(n);
}
}
Node* prev_fusion_group =
!initial_fusion_groups.empty() ? initial_fusion_groups[0] : nullptr;
for (const auto i : c10::irange(1, initial_fusion_groups.size())) {
// Try merging the just created fusion group into the previous one.
// If it did not work, then put the previous fusion group into
// fusion_groups vector - we will not touch it anymore in this loop.
// If merging succeeded, save the merged group as the "previous" fusion
// group so that we can try to merge the next one into it.
Node* fusion_group = initial_fusion_groups[i];
debugDumpFusionGroup(
"Trying to merge into the previous fusion group: ",
prev_fusion_group);
if (auto merged_fusion_group =
tryMerge(prev_fusion_group, fusion_group)) {
prev_fusion_group = *merged_fusion_group;
debugDumpFusionGroup(
"Successfully merged into the previous fusion group: ",
prev_fusion_group);
} else {
GRAPH_DEBUG("Cannot merge into the previous fusion group");
prev_fusion_group = fusion_group;
}
}
}
size_t blockSize(Block* block) {
size_t num = 0;
for (Node* n : block->nodes()) {
// Don't count prim::Constants and prim::ListConstructs as these are nodes
// we only pull in along with another, "main", node. E.g. the
// ListConstruct nodes would also be pulled into a fusion group if they
// are inputs of an aten::cat node.
if (n->kind() == prim::Constant || n->kind() == prim::ListConstruct) {
continue;
}
for (Block* b : n->blocks()) {
num += blockSize(b);
}
num++;
}
return num;
}
bool hasConv(Block* block) {
for (Node* n : block->nodes()) {
if (n->kind() == aten::conv2d) {
return true;
}
}
return false;
}
bool inlineIfTooSmall(Node* n) {
if (n->kind() != prim::TensorExprGroup) {
return false;
}
auto subgraph = SubgraphUtils::getSubgraph(n);
size_t num_nodes = blockSize(subgraph->block());
// Allow small subgraphs containing conv2d, since we'll only select those
// in cases where the tensorexpr implementation is faster than the aten
// implementation.
if (num_nodes < min_group_size_ && !hasConv(subgraph->block())) {
GRAPH_UPDATE("Fusion group is too small, unmerging: ", *n);
SubgraphUtils::unmergeSubgraph(n);
return true;
}
// Cleanup the subgraph from duplicated constants while we're at it.
ConstantPooling(subgraph);
if (GRAPH_DEBUG_ENABLED) {
GRAPH_EXPORT("", subgraph);
}
return false;
}
void inlineSmallFusionGroups(Block* block) {
for (auto it = block->nodes().begin(); it != block->nodes().end();) {
Node* n = *it;
it++;
for (Block* b : n->blocks()) {
inlineSmallFusionGroups(b);
}
inlineIfTooSmall(n);
}
}
std::optional<Node*> tryMerge(Node* fusion_group, Node* to_merge) {
if (!canMerge(fusion_group, to_merge)) {
return std::nullopt;
}
std::vector<Node*> nodes_to_merge = {to_merge};
if (to_merge->kind() == aten::cat) {
Node* listconstruct = to_merge->input(0)->node();
nodes_to_merge.push_back(listconstruct);
}
// First, try to move all the nodes we want to fuse next to the fusion
// group.
Node* move_point = fusion_group;
for (auto n : nodes_to_merge) {
GRAPH_UPDATE("Trying to move node next to fusion group: ", getHeader(n));
if (!aliasDb_->moveBeforeTopologicallyValid(n, move_point)) {
GRAPH_UPDATE("Failed to move because of AliasDB checks!");
return std::nullopt;
}
move_point = n;
}
// Now all the nodes that we're going to fuse are moved next to the fusion
// group, so we can safely merge them into the fusion group subgraph.
fusion_group = getOrCreateTensorExprSubgraph(fusion_group);
for (auto n : nodes_to_merge) {
GRAPH_UPDATE("Merging ", getHeader(n));
SubgraphUtils::mergeNodeIntoSubgraphAndUpdateAliasing(
n, fusion_group, *aliasDb_);
}
return fusion_group;
}
bool shapeIsKnown(Value* v) {
if (v->type()->cast<TensorType>()) {
if (!v->isCompleteTensor()) {
return false;
}
}
return true;
}
bool allShapesAreKnown(Node* node) {
// TODO: Relax the checks to support dynamic shapes
for (Value* input : node->inputs()) {
if (!shapeIsKnown(input)) {
return false;
}
if (input->node()->kind() == prim::ListConstruct) {
if (!allShapesAreKnown(input->node())) {
return false;
}
}
}
for (Value* output : node->outputs()) {
if (!shapeIsKnown(output)) {
return false;
}
}
return true;
}
bool canFuseOnDevice(Value* v) {
auto type = v->type()->cast<TensorType>();
if (!type) {
return true;
}
auto device = type->device();
if (!device) {
return false;
}
if (device->is_cpu()) {
return canFuseOnCPU();
} else if (device->is_cuda()) {
return canFuseOnGPU();
} else if (device->is_xpu()) {
return false;
}
return false;
}
bool isFusableOnDevice(Node* node) {
for (const auto& input : node->inputs()) {
if (input->node()->kind() == prim::ListConstruct) {
if (!isFusableOnDevice(input->node())) {
return false;
}
}
if (!canFuseOnDevice(input)) {
return false;
}
}
return true;
}
bool typesAreSupported(Node* node) {
// clang-format off
// breaks up the schema strings so they are no longer discoverable with ctrl-F
static const OperatorSet float_only_operator_set{
"aten::fmod.Scalar(Tensor self, Scalar other) -> Tensor",
"aten::fmod.Tensor(Tensor self, Tensor other) -> Tensor",
"aten::remainder.Scalar(Tensor self, Scalar other) -> Tensor",
"aten::remainder.Tensor(Tensor self, Tensor other) -> Tensor",
};
static const OperatorSet int_only_operator_set{
"aten::__lshift__.Scalar(Tensor self, Scalar other) -> Tensor",
"aten::__lshift__.Tensor(Tensor self, Tensor other) -> Tensor",
"aten::__rshift__.Scalar(Tensor self, Scalar other) -> Tensor",
"aten::__rshift__.Tensor(Tensor self, Tensor other) -> Tensor",
};
static const OperatorSet cpu_compute_heavy_set{
"aten::conv2d(Tensor input, Tensor weight, Tensor? bias=None, int[2] stride=1, int[2] padding=0, int[2] dilation=1, int groups=1) -> Tensor",
"aten::_convolution(Tensor input, Tensor weight, Tensor? bias, int[] stride, int[] padding, int[] dilation, bool transposed, int[] output_padding, int groups, bool benchmark, bool deterministic, bool cudnn_enabled, bool allow_tf32) -> Tensor",
"aten::matmul(Tensor self, Tensor other) -> Tensor",
};
static const OperatorSet gpu_only_operator_set{
// On CPU, these are slower and less accurate than ATen kernels, because
// ATen is able to use MKL-VML, whereas the fuser currently can't. The
// fuser uses sleef instead because sleef provides functions that operate
// on vectors, instead of large buffers.
"aten::erf(Tensor self) -> Tensor",
"aten::erfc(Tensor self) -> Tensor",
};
static const OperatorSet pow{
"aten::pow.Tensor_Scalar(Tensor self, Scalar exponent) -> Tensor",
};
// Check types of input values.
for (const Value* v : node->inputs()) {
if (auto const& tt = v->type()->cast<TensorType>()) {
auto const& st = tt->scalarType();
auto const& device = tt->device();
// All tensors must be typed.
if (!st || !device) {
return false;
}
// Byte tensors introduce too many corner cases in type promotion.
// Better not to try to handle them.
if (*st == c10::ScalarType::Byte) {
return false;
}
// Float16 support has some issues (see e.g. #61336 and #61382), so for
// now it's disabled. There seem to be some problems in HalfRewriter,
// but on top of that Float16 has a few kinks on LLVM. Thus, on CPU we
// additionally disable it until we either move to a more stable version
// or find workarounds.
if (*st == c10::ScalarType::Half && *device == c10::kCPU) {
return false;
}
if (*st == c10::ScalarType::BFloat16 && *device == c10::kCPU) {
#ifndef TORCH_ENABLE_LLVM
return false;
#endif
}
// These operators only support floats, because integer divisors need to
// raise ZeroDivisionError.
if (node->isMemberOf(float_only_operator_set) && !isFloatingType(*st)) {
return false;
}
// These operators have complicated casting rules for floats.
if (node->isMemberOf(int_only_operator_set) && isFloatingType(*st)) {
return false;
}
} else if (node->isMemberOf(float_only_operator_set)) {
// Check scalar operands of float-only ops.
if (!v->type()->cast<FloatType>()) {
return false;
}
} else if (node->isMemberOf(int_only_operator_set)) {
if (!v->type()->cast<IntType>()) {
return false;
}
}
}
// aten::pow has special rules to avoid complicated integer cases. We
// expect the first arg to be a floating point tensor, and if that's the
// case the type of the scalar exponent doesn't matter.
if (node->isMemberOf(pow)) {
auto const& tt = node->input(0)->type()->cast<TensorType>();
if (!tt) {
return false;
}
auto const& st = tt->scalarType();
if (!st || !isFloatingType(*st)) {
return false;
}
}
// Operator is only supported on CPU.
if (node->isMemberOf(cpu_compute_heavy_set)) {
if (fuse_to_dynamic_shapes_) {
return false;
}
auto device = tensorexpr::pickDeviceType(node->inputs());
if (!device) {
device = tensorexpr::pickDeviceType(node->outputs());
}
if (!device || !device->is_cpu()) {
return false;
}
}
// Operator is only supported on GPU.
if (node->isMemberOf(gpu_only_operator_set)) {
auto device = tensorexpr::pickDeviceType(node->inputs());
if (!device) {
device = tensorexpr::pickDeviceType(node->outputs());
}
if (!device || !device->is_cuda()) {
return false;
}
}
if (node->kind() == aten::to) {
// only support same-device conversion
auto device = tensorexpr::pickDeviceType(node->inputs());
auto output_device = tensorexpr::pickDeviceType(node->outputs());
if (!device || !output_device || *device != *output_device) {
return false;
}
// non_blocking only applies in cross-device conversion, which we bail on
// copy arg only applies if op is a no-op, which we dont start fusion
// group from memory format is separately handled in NNC output
// all non-Tensor arguments must be constant
for (size_t i = 1; i < node->inputs().size(); i++) {
if (node->inputs().at(i)->node()->kind() != prim::Constant) {
return false;
}
}
if (has_unsupported_pin_memory(node)) {
return false;
}
}
if (node->kind() == aten::_autocast_to_reduced_precision ||
node->kind() == aten::_autocast_to_full_precision) {
for (auto i : c10::irange(1, node->inputs().size())) {
if (node->inputs().at(i)->node()->kind() != prim::Constant) {
return false;
}
}
bool is_reduced_precision =
node->kind() == aten::_autocast_to_reduced_precision;
bool is_full_precision =
node->kind() == aten::_autocast_to_full_precision;
auto self_tensor = node->inputs()[0]; // input tensor
if (auto const& tt = self_tensor->type()->cast<TensorType>()) {
auto st = tt->scalarType();
if (!st.has_value()) {
return false;
}
auto device = tt->device();
if (!device.has_value()) {
return false;
}
bool is_cpu = device->is_cpu();
if (*st != at::kFloat && is_reduced_precision && is_cpu) {
// Regarding CPU, aten would do nothing if the data type is
// float. Then the aten performance is better than NNC. So NNC
// does not pull it into its fusion group.
return false;
}
if (*st != at::kBFloat16 && is_full_precision && is_cpu) {
// Regarding CPU, aten would do nothing if the data type is
// BFloat16. Then the aten performance is better than NNC. So NNC
// does not pull it into its fusion group.
return false;
}
}
if (has_unsupported_pin_memory(node)) {
return false;
}
}
if (node->kind() == aten::unsqueeze) {
// `dim` argument must be a constant.
if (node->input(1)->node()->kind() != prim::Constant) {
return false;
}
}
if (node->kind() == aten::_convolution && !tensorexpr::isConv2d(node)) {
GRAPH_DEBUG("This aten::_convolution node is not a 2D conv");
return false;
}
if (node->kind() == aten::_convolution || node->kind() == aten::conv2d) {
if (!tensorexpr::conv2dIsSupportedJit(node) &&
!tensorexpr::mkldnnPrepackedConvIsSupportedJit(node)) {
GRAPH_DEBUG("Params of conv2d are not supported");
return false;
}
}
if (node->kind() == aten::matmul) {
if (!tensorexpr::matmulIsSupported(node)) {
GRAPH_DEBUG("Shapes of matmul inputs are not supported");
return false;
}
}
return true;
}
#define REQ(cond) \
if (!(cond)) { \
GRAPH_DEBUG("Failed cond " #cond "\n"); \
return false; \
}
bool canHandle(Node* node) {
REQ(allShapesAreKnown(node));
REQ(isFusableOnDevice(node));
REQ(operators_not_to_fuse.find(node->kind()) ==
operators_not_to_fuse.end());
for (Value* input : node->inputs()) {
if (auto const& tt = input->type()->cast<TensorType>()) {
auto st = tt->scalarType();
if (!st) {
// All tensor types should be known.
return false;
}
if (c10::isComplexType(*st) || c10::isQIntType(*st)) {
return false;
}
}
}
if (node->kind() == aten::cat) {
REQ(node->input(0)->node()->kind() == prim::ListConstruct);
REQ(node->input(0)->uses().size() == 1);
REQ(node->input(1)->node()->kind() == prim::Constant);
auto const& listconstruct = node->input(0)->node();
REQ(tensorexpr::pickDeviceType(listconstruct->inputs()));
} else {
REQ(tensorexpr::pickDeviceType(node->inputs()));
}
// Only fuse aten::batch_norm when the parameter 'training' is false
if (node->kind() == aten::batch_norm) {
REQ(node->input(5)->node()->kind() == prim::Constant);
REQ(!toIValue(node->input(5)).value().toBool());
}
REQ(tensorexpr::isSupported(node));
REQ(typesAreSupported(node));
// A hook to optimizations limiter to allow bisecting the pass
REQ(JIT_OPT_ALLOWED);
if (fuse_to_dynamic_shapes_) {
// Allow only if the node has a shape function defined.
// ListConstruct node is an exception since that is needed to fuse
// aten::cat, though it does not have a shape function.
REQ(node->kind() == prim::ListConstruct ||
node->kind() == prim::TensorExprGroup ||
node->isMemberOf(tensorexpr::getCustomOperatorSet()) ||
(node->maybeSchema() && shapeComputeGraphForSchema(node->schema())));
}
return true;
}
bool canMerge(Node* consumer, Node* producer) {
// Only fuse within a block
REQ(consumer->owningBlock() == producer->owningBlock());
// Symbolic checks
REQ(canHandle(producer) || producer->kind() == prim::TensorExprGroup);
TORCH_INTERNAL_ASSERT(
consumer->kind() == prim::TensorExprGroup || canHandle(consumer));
// nvrtc has a limit on the number of arguments allowed in a CUDA kernel.
// The specific limit is a function of constant memory size, amount
// available to pass arguments, and some implementation dependence. Select a
// safe limit here.
constexpr size_t subgraphArgLimit = 128;
auto const nInputs = consumer->inputs().size() +
consumer->outputs().size() + producer->inputs().size() +
producer->outputs().size();
REQ(nInputs <= subgraphArgLimit);
// Device checks
if (consumer->kind() != aten::cat && producer->kind() != aten::cat) {
// aten::cat needs a special handling because it takes a Tensor[] as its
// input We deal with that in the code below.
auto consumer_device = tensorexpr::pickDeviceType(consumer->inputs());
REQ(consumer_device);
auto producer_device = tensorexpr::pickDeviceType(producer->inputs());
REQ(producer_device);
REQ(*consumer_device == *producer_device);
}
// Alias checks
REQ(aliasDb_->couldMoveBeforeTopologically(producer, consumer));
// Ops that return aliases can only be folded if this is the only use.
if (producer->kind() == aten::slice ||
producer->kind() == aten::unsqueeze ||
producer->kind() == prim::ConstantChunk) {
for (auto& use : producer->output(0)->uses()) {
REQ(use.user == consumer);
}
}
if (!consumer->hasAttribute(attr::Subgraph) &&
consumer->kind() != prim::TensorExprGroup) {
// Don't initiate a fusion group from prim::ListConstruct
REQ(consumer->kind() != prim::ListConstruct);
REQ(consumer->kind() != aten::slice);
REQ(consumer->kind() != aten::unsqueeze);
REQ(consumer->kind() != prim::ConstantChunk);
// Don't initiate a fusion group just for a constant operand
REQ(producer->kind() != prim::Constant);
}
if (producer->kind() == aten::cat) {
REQ(producer->input(0)->node()->kind() == prim::ListConstruct);
REQ(producer->input(0)->uses().size() == 1);
REQ(producer->input(1)->node()->kind() == prim::Constant);
auto const& listConstruct = producer->input(0)->node();
// We're merging listconstruct->cat->consumer. cat is the producer here
// and we cannot determine its device type - we should use device of the
// listconstruct instead
auto listconstruct_device =
tensorexpr::pickDeviceType(listConstruct->inputs());
auto consumer_device = tensorexpr::pickDeviceType(consumer->inputs());
REQ(listconstruct_device);
REQ(consumer_device);
REQ(*listconstruct_device == *consumer_device);
for (auto const& input : listConstruct->inputs()) {
REQ(isFusableOnDevice(input->node()));
}
REQ((nInputs + listConstruct->inputs().size()) <= subgraphArgLimit);
} else if (consumer->kind() == aten::cat) {
REQ(consumer->input(0)->node()->kind() == prim::ListConstruct);
REQ(consumer->input(0)->uses().size() == 1);
REQ(consumer->input(1)->node()->kind() == prim::Constant);
auto const& listConstruct = consumer->input(0)->node();
// We're merging listconstruct->cat. cat is the consumer and listconstruct
// is the producer. cat doesn't have its device type and thus the only
// thing we should check is that listconstruct's device is well defined
// (e.g. all its inputs has the same device).
auto listconstruct_device =
tensorexpr::pickDeviceType(listConstruct->inputs());
REQ(listconstruct_device);
REQ((nInputs + listConstruct->inputs().size()) <= subgraphArgLimit);
} else {
REQ(isFusableOnDevice(producer));
}
return true;
}
#undef REQ
void prepareFusionGroupAndGuardOutputs(Block* block) {
std::vector<Node*> fusion_groups;
for (Node* n : block->nodes()) {
for (Block* b : n->blocks()) {
prepareFusionGroupAndGuardOutputs(b);
}
if (n->kind() == prim::TensorExprGroup) {
fusion_groups.push_back(n);
}
}
for (Node* fusion_group : fusion_groups) {
removeOutputsUsedOnlyInSize(fusion_group);
insertTypeGuard(
fusion_group,
[](const TensorTypePtr& t) { return t; },
prim::TypeCheck);
}
}
void generalizeFusionGroups(Block* block) {
std::vector<Node*> fusion_groups;
for (Node* n : block->nodes()) {
for (Block* b : n->blocks()) {
generalizeFusionGroups(b);
}
if (n->kind() == prim::TensorExprGroup) {
fusion_groups.push_back(n);
}
}
for (Node* fusion_group : fusion_groups) {
removeOutputsUsedOnlyInSize(fusion_group);
VLOG(1) << "GenerateGuard for fusion group: " << *fusion_group;
if (!GenerateGuard(fusion_group, add_composed_op_)) {
VLOG(1) << " Unfusing the fusion group because GenerateGuard failed"
<< '\n';
SubgraphUtils::unmergeSubgraph(fusion_group);
}
}
}
// This function parses the option provided by the environment variable
// "PYTORCH_TENSOREXPR_DONT_FUSE".
// This variable allows users to disable fusion on a list of specified
// operators that are separated by ':'. e.g.,
// 'PYTORCH_TENSOREXPR_DONT_FUSE="clamp:mul:add"' disables fusion on
// aten::clamp, aten::mul and aten::add.
void parseTENotFuseOption() {
const auto option = c10::utils::get_env("PYTORCH_TENSOREXPR_DONT_FUSE");
std::stringstream in_ss;
if (option.has_value()) {
in_ss << option.value();
}
std::string line;
while (std::getline(in_ss, line, ':')) {
if (line.empty()) {
continue;
}
operators_not_to_fuse.insert(c10::Symbol::aten(line));
}
}
std::shared_ptr<Graph> graph_;
std::unique_ptr<AliasDb> aliasDb_ = nullptr;
std::set<NodeKind> operators_not_to_fuse;
// Minimal size of a fusion group
size_t min_group_size_;
// compose Runtime Type Guard and Kernel in one op
bool add_composed_op_;
// generalize static shapes to dynamic shapes
bool fuse_to_dynamic_shapes_;
};
void FuseTensorExprs(
std::shared_ptr<Graph>& graph,
size_t min_group_size,
bool add_composed_op,
bool fuse_to_dynamic_shapes) {
GRAPH_DUMP("Before TExprFuser: ", graph);
// Temporary change for Block code generation.
if (tensorexpr::getTEGenerateBlockCode()) {
min_group_size = 1;
}
if (add_composed_op) {
TORCH_INTERNAL_ASSERT(
fuse_to_dynamic_shapes, "Fusing static shapes with composed op NYI");
}
// Get rid of dead code so that we don't waste effort fusing it.
EliminateDeadCode(graph);
TensorExprFuser fuser(
graph, min_group_size, add_composed_op, fuse_to_dynamic_shapes);
fuser.run();
EliminateCommonSubexpression(graph);
EliminateDeadCode(graph);
GRAPH_DUMP("After TExprFuser: ", graph);
}
static Operation createTensorExprOp(const Node* node) {
bool dynamic_shape_fusion_node =
node->hasAttribute(attr::striding_inputs_desc);
if (!dynamic_shape_fusion_node) {
auto kernel =
std::make_shared<tensorexpr::TensorExprKernel>(node->g(attr::Subgraph));
return [kernel](Stack& stack) {
RECORD_FUNCTION(kernel->getKernelName(), std::vector<c10::IValue>());
kernel->run(stack);
return 0;
};
}
// Handle the case when dynamic shape fusion is enabled.
VLOG(1) << "Compiling a new kernel for " << *node;
std::vector<int64_t> sym_shapes;
if (node->hasAttribute(attr::symbolic_shape_inputs)) {
sym_shapes = node->is(attr::symbolic_shape_inputs);
}
bool allow_stack_outputs = false;
if (node->hasAttribute(attr::allow_stack_outputs)) {
allow_stack_outputs = node->i(attr::allow_stack_outputs) == 1;
}
std::unordered_map<c10::Symbol, tensorexpr::NNCLoweringFunction>
custom_lowerings;
auto subgraph = node->g(attr::Subgraph);
IValue sym_strides = node->ival(attr::striding_inputs_desc);
// Striding Descriptor is serialized on the node as a vector of vector of
// strings, translate back to StrideInput enum
std::vector<std::vector<std::string>> sym_strides_strs =
sym_strides.to<std::vector<std::vector<std::string>>>();
std::vector<std::vector<StrideInput>> striding_inputs;
for (const auto& vec : sym_strides_strs) {
std::vector<StrideInput> input_desc;
input_desc.reserve(vec.size());
for (const std::string& str : vec) {
input_desc.push_back(strideInputFromString(str));
}
striding_inputs.push_back(input_desc);
}
std::unordered_map<const Value*, std::vector<StrideInput>> stride_map;
size_t index = 0;
for (Value* v : subgraph->inputs()) {
if (!v->type()->cast<TensorType>()) {
continue;
}
stride_map[v] = striding_inputs[index];
index++;
}
std::vector<std::string> output_desc =
node->ival(attr::striding_outputs_desc).to<std::vector<std::string>>();
for (size_t i = 0; i < subgraph->outputs().size(); ++i) {
stride_map[subgraph->outputs().at(i)] = {
strideInputFromString(output_desc.at(i))};
}
std::shared_ptr<tensorexpr::TensorExprKernel> kernel =
std::make_shared<tensorexpr::TensorExprKernel>(
subgraph,
custom_lowerings,
sym_shapes,
/*pre_alloc*/ false,
stride_map);
auto num_subgraph_inputs = subgraph->inputs().size();
return [kernel, num_subgraph_inputs, allow_stack_outputs](Stack& stack) {
RECORD_FUNCTION(kernel->getKernelName(), std::vector<c10::IValue>());
// Stack contents:
// [<outputs>] <inputs>
//
// If the number of graph inputs is same as the stack size, then no
// outputs are being passed in. Otherwise, output tensors are passed in
// at the bottom of the stack. So, we call the appropriate run function
// in TensorExprKernel.
if (num_subgraph_inputs == stack.size() || !allow_stack_outputs) {
kernel->run(stack);
} else {
kernel->runWithAllocatedOutputs(stack);
}
return 0;
};
}
static RegisterOperators TensorExprOps({
torch::jit::Operator(
prim::TensorExprGroup,
createTensorExprOp,
AliasAnalysisKind::INTERNAL_SPECIAL_CASE),
});
} // namespace torch::jit