pytorch/torch/csrc/jit/script/compiler.cpp
Elias Ellison ca76c82ce3 Add early returns to JIT (#19179)
Summary:
Add early returns to JIT with minimal changes to compiler.cpp and an IR->IR pass that will transform the graph so that there is only one return value.

In compiler.cpp, record when a block will exit so that in the following example will work:
```
if cond:
    a = torch.zeros([2])
else:
    return 2
a += 2
...
```
To match block outputs with values that will not be used, like in the above example with `a`, I add a Bottom Type that subtypes everything else. This allows shape propagation to continue to work, and makes it so that we don't need many extra nodes filling up the graph.

The IR transform currently doesn't work on Loops, I didn't add that to this PR to avoid too much complexity, but will add it as a stack (and it should be very little extra code). the IR  transform is commented at the top of the file.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/19179

Differential Revision: D16519819

Pulled By: eellison

fbshipit-source-id: 322a27f69966d1fd074ebe723c3e948b458b0e68
2019-07-26 16:42:43 -07:00

3282 lines
117 KiB
C++

#include <torch/csrc/jit/script/compiler.h>
#include <c10/util/Exception.h>
#include <c10/util/StringUtil.h>
#include <torch/csrc/jit/hooks_for_testing.h>
#include <torch/csrc/jit/interpreter.h>
#include <torch/csrc/jit/ir.h>
#include <torch/csrc/jit/operator.h>
#include <torch/csrc/jit/passes/canonicalize.h>
#include <torch/csrc/jit/passes/constant_pooling.h>
#include <torch/csrc/jit/passes/dead_code_elimination.h>
#include <torch/csrc/jit/passes/inline_forked_closures.h>
#include <torch/csrc/jit/passes/inliner.h>
#include <torch/csrc/jit/passes/lift_closures.h>
#include <torch/csrc/jit/passes/lower_tuples.h>
#include <torch/csrc/jit/script/canonicalize_modified_loop.h>
#include <torch/csrc/jit/script/convert_to_ssa.h>
#include <torch/csrc/jit/script/parser.h>
#include <torch/csrc/jit/script/schema_matching.h>
#include <torch/csrc/jit/script/script_type_parser.h>
#include <torch/csrc/jit/constants.h>
#include <c10/util/Optional.h>
#include <atomic>
#include <climits>
#include <set>
namespace torch {
namespace jit {
namespace script {
using FunctionTable = std::unordered_map<std::string, Function&>;
using ValueTable = std::unordered_map<std::string, SugaredValuePtr>;
using TypeTable = std::unordered_map<std::string, TypePtr>;
using AttributeMap = std::unordered_map<std::string, Const>;
using ListAttributeMap = std::unordered_map<std::string, std::vector<Const>>;
using TypeAndRange = std::pair<TypePtr, const SourceRange*>;
// Holds mappings from a variable name to a refined type for that variable
// E.g if x is not None is true than we can refine x from type t? to t.
struct Refinements {
// using ordered map for deterministic graph output
std::map<std::string, TypeAndRange> mappings_;
void setRefinement(const std::string& name, TypeAndRange mapping) {
mappings_[name] = std::move(mapping);
}
c10::optional<TypeAndRange> getRefinement(const std::string& name) const {
const auto& maybe_mapping = mappings_.find(name);
if (maybe_mapping == mappings_.end()) {
return c10::nullopt;
}
return maybe_mapping->second;
}
// return the intersection of the values to type mappings between this
// types can be unified
void intersectRefinements(const Refinements& other) {
Refinements ret;
for (const auto& name_mapping : mappings_) {
const auto& name = name_mapping.first;
const auto& mapping = name_mapping.second;
if (auto other_mapping = other.getRefinement(name_mapping.first)) {
const auto maybe_unified_type =
unifyTypes(mapping.first, other_mapping->first);
if (maybe_unified_type) {
ret.setRefinement(
name, TypeAndRange(*maybe_unified_type, mapping.second));
}
}
}
mappings_ = std::move(ret.mappings_);
}
// return the union of the values to type mappings in a and b whose
// types can be unified
void unionRefinements(const Refinements& other) {
Refinements ret;
for (const auto& name_mapping : mappings_) {
const auto& name = name_mapping.first;
const auto& mapping = name_mapping.second;
TypePtr t_1 = mapping.first;
if (auto other_mapping = other.getRefinement(name_mapping.first)) {
TypePtr t_2 = other_mapping->first;
c10::optional<TypePtr> maybe_unified_type = c10::nullopt;
if (t_1->isSubtypeOf(t_2)) {
maybe_unified_type = t_1;
} else if (t_2->isSubtypeOf(t_1)) {
maybe_unified_type = t_2;
}
if (maybe_unified_type) {
ret.setRefinement(
name, TypeAndRange(*maybe_unified_type, mapping.second));
}
} else {
ret.setRefinement(name, mapping);
}
}
for (auto& name_mapping : other.mappings_) {
if (!getRefinement(name_mapping.first)) {
ret.setRefinement(name_mapping.first, name_mapping.second);
}
}
mappings_ = std::move(ret.mappings_);
}
};
// When a comparison like x is None is made, we associate type refinements
// with its true value and its false value. If a boolean that has refinements
// associated with it is used in a conditional of an if statememt, the true and
// false refinements are inserted into the corresponding blocks
struct BoolInfo {
BoolInfo(Refinements true_refinements, Refinements false_refinements)
: true_refinements_(std::move(true_refinements)),
false_refinements_(std::move(false_refinements)){};
BoolInfo() = default;
Refinements true_refinements_;
Refinements false_refinements_;
BoolInfo* mergeOr(const BoolInfo& other) {
// if the result of an OR is true, either a & b could have been true,
// so we take the intersection of a.true_refinements & b.true_refinements.
// if the result is false, both a and b had to be false,
// so we take their union.
true_refinements_.intersectRefinements(other.true_refinements_);
false_refinements_.unionRefinements(other.false_refinements_);
return this;
}
BoolInfo* mergeAnd(const BoolInfo& other) {
// if the result of an AND is true, both a & b had to be true,
// so we take the union of a.true_refinements and b.true_refinements.
// if the result is false, either a or b could have been false,
// so we take their intersection.
true_refinements_.unionRefinements(other.true_refinements_);
false_refinements_.intersectRefinements(other.false_refinements_);
return this;
}
};
static Value* asSimple(const SugaredValuePtr& value) {
if (SimpleValue* sv = dynamic_cast<SimpleValue*>(value.get())) {
return sv->getValue();
}
return nullptr;
}
static std::shared_ptr<MagicMethod> makeMagic(
const std::string& name,
SugaredValuePtr base) {
return std::make_shared<MagicMethod>(name, base);
}
// Auxiliary data structure for desugaring variable binding into our always
// explicitly scoped language as we descend down nested control structures in
// the frontend (which themselves don't introduce scopes)
//
// The Environment keeps track of two tables, one for values which are not first
// class and a type table for values which are. When a first class value
// is set in the environment, we emit a prim::Store which sets the
// name of the variable to approriate type, and when a first-class value is
// referenced we emit a prim::Load that generates a value of the appropriate
// type.
//
// a = 1
// print(a)
// becomes:
// = prim::Store[name="a"](%a.1)
// %a : int = prim::Load[name="a"]()
// prim::Print(%a)
struct Environment {
Environment(
Function& method,
ResolverPtr resolver,
Block* b,
std::shared_ptr<Environment> next = nullptr)
: method(method),
resolver(std::move(resolver)),
b(b),
next(std::move(next)) {}
Function& method;
ResolverPtr resolver;
std::unordered_map<std::string, std::function<std::string()>> error_messages;
Block* b;
std::shared_ptr<Environment> next;
// set type error in the lowest environment. if the variable is used after an
// error has been set, then we will use the more informative error message
void setVariableTypeError(
const std::string& name,
std::function<std::string()> msg) {
auto runner = this;
while (runner->next) {
runner = runner->next.get();
}
runner->error_messages[name] = msg;
}
// see if type error has been set for a variable
c10::optional<std::string> findVariableTypeError(const std::string& name) {
auto runner = this;
while (runner->next) {
runner = runner->next.get();
}
auto msg = runner->error_messages.find(name);
if (msg != runner->error_messages.end()) {
return msg->second();
} else {
return c10::nullopt;
}
}
SugaredValuePtr insertLoad(const std::string& name, const TypePtr& type) {
auto g = b->owningGraph();
auto load = g->insertNode(g->createLoad(name, type));
if (meaningfulName(name)) {
load->output()->setDebugName(name);
}
return std::make_shared<SimpleValue>(load->output());
}
void insertStore(const std::string& name, const SourceRange& loc, Value* v) {
auto g = b->owningGraph();
auto store = g->insertNode(g->createStore(name, v))->setSourceRange(loc);
type_table[name] = store->input()->type();
}
SugaredValuePtr findInThisFrame(const std::string& name) {
auto it = value_table.find(name);
if (it != value_table.end()) {
return it->second;
}
auto it2 = type_table.find(name);
if (it2 != type_table.end()) {
return insertLoad(name, it2->second);
}
return nullptr;
}
SugaredValuePtr findInParentFrame(const std::string& name) {
return next ? next->findInAnyFrame(name) : nullptr;
}
void setType(const std::string& name, TypePtr type) {
type_table[name] = std::move(type);
}
SugaredValuePtr findInAnyFrame(const std::string& name) {
for (auto runner = this; runner; runner = runner->next.get()) {
if (auto r = runner->findInThisFrame(name)) {
return r;
}
}
return nullptr;
}
Block* block() {
return b;
}
void setVar(const SourceRange& loc, const std::string& name, Value* value) {
setSugaredVar(loc, name, std::make_shared<SimpleValue>(value));
}
void setSugaredVar(
const SourceRange& loc,
const std::string& name,
SugaredValuePtr value) {
Value* as_simple_value = asSimple(value);
if (as_simple_value && !as_simple_value->hasDebugName() &&
meaningfulName(name) &&
// note: if the value wasn't defined in this block, we might be giving a
// name only used inside this block to a value outside of this. this is
// not normally helpful for debugging and causes import/export jitter.
as_simple_value->node()->owningBlock() == block()) {
as_simple_value->setDebugName(name);
}
// prevent re-assignment involving any sugared values
// any reassignment like:
// a = ...
// while ...
// a = ..
// requires 'a' to be first-class in the graph since its value depends on
// control flow
if (auto parent = findInParentFrame(name)) {
if (!as_simple_value) {
throw ErrorReport(loc)
<< "Cannot re-assign '" << name << "' to a value of type "
<< value->kind() << " because " << name
<< " is not a first-class value. Only reassignments to first-class values are allowed";
}
Value* simple_parent = asSimple(parent);
if (!simple_parent) {
throw ErrorReport(loc)
<< "Cannot re-assign '" << name << "' because it has type "
<< value->kind() << " and " << name
<< " is not a first-class value. Only reassignments to first-class values are allowed";
}
if (!as_simple_value->type()->isSubtypeOf(
unshapedType(simple_parent->type()))) {
auto error = ErrorReport(loc);
error << "Variable '" << name << "' previously has type "
<< simple_parent->type()->python_str()
<< " but is now being assigned to a value of type "
<< as_simple_value->type()->python_str();
// Special-cased error msg if we're trying to assign to a tensor list.
if (simple_parent->type()->kind() == TypeKind::ListType &&
as_simple_value->type()->kind() == TypeKind::ListType) {
error << "\n. (Note: empty lists are constructed as Tensor[]; "
<< "if you want an empty list of a different type, "
<< "use `torch.jit.annotate(List[T], [])`, "
<< "where `T` is the type of elements in the list)";
}
throw error;
}
}
if (as_simple_value) {
insertStore(name, loc, std::move(as_simple_value));
} else {
value_table[name] = std::move(value);
}
}
SugaredValuePtr getSugaredVar(const Ident& ident, bool required = true) {
return getSugaredVar(ident.name(), ident.range());
}
Value* getVar(const Ident& ident) {
return getSugaredVar(ident)->asValue(ident.range(), method);
}
SugaredValuePtr getSugaredVar(
const std::string& ident,
const SourceRange& range,
bool required = true) {
auto retval = findInAnyFrame(ident);
if (!retval) {
static std::unordered_map<std::string, SugaredValuePtr> globals = {
{"print", std::make_shared<PrintValue>()},
{"float",
makeMagic(
"__float__",
std::make_shared<CastValue>(FloatType::get(), aten::Float))},
{"int",
makeMagic(
"__int__",
std::make_shared<CastValue>(IntType::get(), aten::Int))},
{"bool",
makeMagic(
"__bool__",
std::make_shared<CastValue>(BoolType::get(), aten::Bool))},
{"str",
makeMagic(
"__str__",
std::make_shared<CastValue>(StringType::get(), aten::str))},
{"getattr", std::make_shared<GetAttrValue>()},
{"isinstance", std::make_shared<IsInstanceValue>()},
// todo(zach): remove when we can correctly export torch.full via ONNX
// or we have implicit conversion that can convert numbers to tensors
{"_to_tensor",
std::make_shared<CastValue>(TensorType::get(), prim::NumToTensor)},
{"len",
makeMagic(
"__len__",
std::make_shared<BuiltinFunction>(aten::len, at::nullopt))},
{"hex",
makeMagic(
"__hex__",
std::make_shared<BuiltinFunction>(aten::hex, at::nullopt))},
{"oct",
makeMagic(
"__oct__",
std::make_shared<BuiltinFunction>(aten::oct, at::nullopt))},
{"round",
makeMagic(
"__round__",
std::make_shared<BuiltinFunction>(aten::round, at::nullopt))},
{"hash", std::make_shared<BuiltinFunction>(aten::hash, at::nullopt)},
{"min", std::make_shared<BuiltinFunction>(prim::min, at::nullopt)},
{"max", std::make_shared<BuiltinFunction>(prim::max, at::nullopt)},
{"abs", std::make_shared<BuiltinFunction>(prim::abs, at::nullopt)},
{"all", std::make_shared<BuiltinFunction>(aten::all, at::nullopt)},
{"divmod",
std::make_shared<BuiltinFunction>(aten::divmod, at::nullopt)},
{"list", std::make_shared<BuiltinFunction>(aten::list, at::nullopt)},
{"ord", std::make_shared<BuiltinFunction>(aten::ord, at::nullopt)},
{"chr", std::make_shared<BuiltinFunction>(aten::chr, at::nullopt)},
{"bin", std::make_shared<BuiltinFunction>(aten::bin, at::nullopt)},
{"range", std::make_shared<IterableValue>(prim::range)},
{"zip", std::make_shared<IterableValue>(prim::zip)},
{"enumerate", std::make_shared<IterableValue>(prim::enumerate)},
{"rangelist",
std::make_shared<BuiltinFunction>(prim::rangelist, at::nullopt)},
};
auto it = globals.find(ident);
if (it != globals.end()) {
retval = it->second;
}
}
if (!retval) {
if (auto type = resolver->resolveType(ident, range)) {
if (auto class_type = type->cast<ClassType>()) {
retval = std::make_shared<script::ClassValue>(class_type);
} else if (auto tuple_type = type->cast<TupleType>()) {
retval = std::make_shared<script::NamedTupleConstructor>(tuple_type);
}
}
}
if (!retval) {
retval = resolver->resolveValue(ident, method, range);
}
if (!retval && required) {
// check if this value was not emitted in an if statement because of a
// type mismatch. if it was, then we print a more informative error msg
if (auto msg = findVariableTypeError(ident)) {
throw ErrorReport(range) << *msg << "and was used here";
}
throw ErrorReport(range) << "undefined value " << ident;
}
return retval;
}
Value* getVar(const std::string& ident, const SourceRange& range) {
return getSugaredVar(ident, range)->asValue(range, method);
}
std::vector<std::string> definedVariables() {
std::vector<std::string> result;
for (auto& kv : type_table) {
result.push_back(kv.first);
}
return result;
}
private:
TypeTable type_table;
ValueTable value_table;
};
template <class T>
static Value* materializeConstant(
T val,
Graph& graph,
const SourceRange& r,
std::unordered_map<T, Value*>& map) {
auto existing_constant = map.find(val);
if (existing_constant != map.end()) {
return existing_constant->second;
}
WithInsertPoint guard(graph.block()->nodes().front());
auto new_constant = graph.insertConstant(val, nullptr, r);
map[val] = new_constant;
return new_constant;
}
static Value* ensureInt(const SourceRange& range, Value* v) {
if (!v->type()->isSubtypeOf(IntType::get())) {
throw ErrorReport(range)
<< "expected a int but found a " << v->type()->python_str();
}
return v;
}
inline bool isSupportedListElementType(const TypePtr& type) {
return type->isSubtypeOf(TensorType::get()) ||
type->isSubtypeOf(NumberType::get());
}
// Information for each def being emitted.
// Defs can be nested to support closures so we need a stack of this information
// Currently records information about the functions return type.
struct DefContext {
TypePtr declared_return_type_; // nullptr if not annotated
TypePtr merged_return_type_; // nullptr if a Return has not been seen yet
};
struct to_ir {
to_ir(
const Def& def,
ResolverPtr resolver_,
const Self* self,
Function& method) // method being constructed
: method(method),
graph(method.graph()),
resolver(std::move(resolver_)),
typeParser_(resolver),
environment_stack(nullptr) {
AT_ASSERT(resolver);
pushFrame(graph->block(), /*starts_def=*/true);
// Type annotations exclude explicitly typing the "self" parameter, so in
// the case that this is a method with self we expect one fewer parameter
// annotation than the number of parameters this Def takes.
if (self && def.decl().params().size() == 0) {
throw ErrorReport(def.decl().params().range())
<< "methods must have a self argument";
}
method.setSchema(emitDef(def, self, graph->block()));
runCleanupPasses(graph);
}
private:
Function& method;
std::shared_ptr<Graph> graph;
ResolverPtr resolver;
std::unordered_map<int64_t, Value*> integral_constants;
std::unordered_map<double, Value*> fp_constants;
std::unordered_set<Block*> exit_blocks;
ScriptTypeParser typeParser_;
// Singly-linked list of environments. This top element contains a member
// `next` that points to the most immediate enclosing scope's value.
std::shared_ptr<Environment> environment_stack;
std::vector<DefContext> def_stack_;
void pushFrame(Block* b, bool starts_def = false) {
if (starts_def) {
def_stack_.emplace_back();
}
environment_stack =
std::make_shared<Environment>(method, resolver, b, environment_stack);
}
std::shared_ptr<Environment> popFrame(bool ends_def = false) {
auto old_frame = environment_stack;
environment_stack = environment_stack->next;
if (ends_def) {
def_stack_.pop_back();
}
return old_frame;
}
// If the graph might not return, add an implicit None return at the end
void handleMaybeNoReturn(const Def& def, Block* block) {
if (exit_blocks.count(graph->block()) == 0) {
auto decl_ret = def_stack_.back().declared_return_type_;
if (decl_ret && decl_ret != NoneType::get()) {
throw ErrorReport(def.range())
<< "Function was not annotated as having type None, but does not "
<< "return along all paths";
}
WithInsertPoint b(*block->nodes().end());
emitReturn(Return::create(
def.range(), Expr(Compound::create(TK_NONE, def.range(), {}))));
}
}
FunctionSchema emitDef(const Def& def, const Self* self, Block* block) {
auto schema = extractSchemaFromDef(def, self);
// TODO need guards on init returning none
if (schema.returns().size() == 1) {
def_stack_.back().declared_return_type_ = schema.returns().at(0).type();
}
std::vector<Argument> arguments =
emitFormalArguments(def, self, schema, block);
// body
auto stmts_list = def.statements();
emitStatements(stmts_list.begin(), stmts_list.end());
handleMaybeNoReturn(def, block);
std::vector<Argument> returns = {emitOutput(def.range(), schema, block)};
return {def.name().name(), "", std::move(arguments), std::move(returns)};
}
std::vector<IValue> evaluateDefaults(
const SourceRange& r,
const std::vector<Expr>& default_types,
const std::vector<Expr>& default_exprs) {
std::vector<IValue> default_values;
if (default_exprs.empty())
return default_values;
// To evaluate the default expressions, we create a graph with no inputs,
// and whose returns are the default values we need.
// We then run constant prop on this graph and check the results are
// constant. This approach avoids having to have separate handling of
// default arguments from standard expressions by piecing together existing
// machinery for graph generation, constant propgation, and constant
// extraction.
auto tuple_type = Subscript::create(
r,
Var::create(r, Ident::create(r, "Tuple")),
List<Expr>::create(r, default_types));
auto blank_decl = Decl::create(
r, List<Param>::create(r, {}), Maybe<Expr>::create(r, tuple_type));
auto tuple_expr =
TupleLiteral::create(r, List<Expr>::create(r, default_exprs));
auto ret = Return::create(r, tuple_expr);
auto def = Def::create(
r,
Ident::create(r, "defaults"),
blank_decl,
List<Stmt>::create(r, {ret}));
CompilationUnit cu;
cu.define(c10::nullopt, {def}, {resolver}, nullptr);
Stack stack;
// XXX: We need to turn optimization off here because otherwise we try to
// recursively initialize stuff in DecomposeOps.
setGraphExecutorOptimize(false);
cu.get_function(def.name().name()).run(stack);
setGraphExecutorOptimize(true);
return stack.at(0).toTuple()->elements();
}
std::vector<Argument> parseArgsFromDecl(const Decl& decl, const Self* self) {
auto params_begin = decl.params().begin();
auto params_end = decl.params().end();
if (self) {
++params_begin;
}
std::vector<Argument> retval;
std::vector<Expr> default_types;
std::vector<Expr> default_exprs;
// gather any non-empty default arguments
for (auto it = params_begin; it != params_end; ++it) {
auto param = *it;
auto def = param.defaultValue();
if (def.present()) {
default_types.emplace_back(param.type().get());
default_exprs.emplace_back(def.get());
}
}
auto default_values =
evaluateDefaults(decl.range(), default_types, default_exprs);
auto defaults_it = default_values.begin();
for (auto it = params_begin; it != params_end; ++it) {
auto decl_arg = *it;
TypePtr type;
c10::optional<int32_t> N;
bool is_inferred_type = false;
if (!decl_arg.type().present()) {
// If this param doesn't have a type, default to "tensor"
is_inferred_type = true;
type = TensorType::get();
N = c10::nullopt;
} else {
// BroadcastList list can only appear at the argument level
if (auto maybe_broad_list =
typeParser_.parseBroadcastList(decl_arg.type().get())) {
type = maybe_broad_list->first;
N = maybe_broad_list->second;
} else {
type = typeParser_.parseTypeFromExpr(decl_arg.type().get());
N = c10::nullopt;
}
}
c10::optional<IValue> default_value = c10::nullopt;
if (decl_arg.defaultValue().present()) {
default_value = *defaults_it++;
}
auto arg = Argument(
decl_arg.ident().name(),
type,
N,
default_value,
decl_arg.kwarg_only(),
/*alias_info=*/c10::nullopt,
is_inferred_type);
retval.push_back(arg);
}
return retval;
}
std::vector<Argument> parseReturnFromDecl(const Decl& decl) {
// we represent no annoation on a return type as having no values in the
// schema's return() list
// in emitReturn we take the actual return value to be the value of the
// return statement if no one was provided here
if (!decl.return_type().present())
return {};
if (typeParser_.parseBroadcastList(decl.return_type().get()))
throw ErrorReport(decl.return_type().range())
<< "Broadcastable lists cannot appear as a return type";
auto parsed_type = typeParser_.parseTypeFromExpr(decl.return_type().get());
return {Argument(
"",
parsed_type,
/*N =*/c10::nullopt,
/*default_value =*/c10::nullopt,
/*kwarg_only =*/false)};
}
FunctionSchema extractSchemaFromDef(const Def& def, const Self* self) {
const auto name = def.name().name();
std::vector<Argument> args = parseArgsFromDecl(def.decl(), self);
std::vector<Argument> returns = parseReturnFromDecl(def.decl());
return FunctionSchema(
name, "", std::move(args), std::move(returns), false, false);
}
std::vector<Argument> emitFormalArguments(
const Def& def,
const Self* self,
const FunctionSchema& schema,
Block* block) {
std::vector<Argument> arguments; // for schema
// inputs
auto it = def.decl().params().begin();
auto end = def.decl().params().end();
auto expected_annotation_size = def.decl().params().size();
if (self) {
expected_annotation_size--;
}
if (schema.arguments().size() != expected_annotation_size) {
throw ErrorReport(def.decl().params().range())
<< "Number of type annotations for"
<< " function parameters (" << schema.arguments().size() << ")"
<< " does not match the number of parameters on the function ("
<< expected_annotation_size << ")!";
}
if (self) {
AT_ASSERT(it != end);
const auto& name = (*it).ident().name();
Value* new_input = block->addInput()->setDebugName(name);
environment_stack->setSugaredVar(
(*it).ident().range(), name, self->makeSugared(new_input));
arguments.emplace_back(name, new_input->type());
++it;
}
size_t arg_annotation_idx = 0;
for (; it != end; ++it) {
auto& name = (*it).ident().name();
// Add the input to the graph
Value* new_input = block->addInput();
if (meaningfulName(name)) {
new_input->setDebugName(name);
}
// Record the type for the schema and set the Type on the Value*
arguments.push_back(schema.arguments().at(arg_annotation_idx++));
new_input->setType(arguments.back().type());
// NB: set type of new_input before setVar call so the Store is
// typed appropriately
environment_stack->setVar((*it).ident().range(), name, new_input);
}
return arguments;
}
Argument emitOutput(
const SourceRange& range,
const FunctionSchema& schema,
Block* block) {
// rewrites ensure there is always a return statement in program
auto ret_type = def_stack_.back().merged_return_type_;
AT_ASSERT(ret_type);
// in the ConvertToSSA pass, prim::ReturnStmts are lowered so that the
// correct return value is set. Until then, we have a correctly-typed
// placeholder return value. This is needed so that closures & graphs
// are correctly typed.
auto placeholder_return =
graph->insertNode(graph->createUninitialized(ret_type))->output();
block->registerOutput(placeholder_return);
return Argument("", def_stack_.back().merged_return_type_);
}
void emitStatements(const List<Stmt>& statements) {
return emitStatements(statements.begin(), statements.end());
}
// XXX - right now closures are used _only_ for defining gradients internally
// There are several unfinished aspects that make them unusable generally
// 1. We do not have a type, ivalue, operator to represent prim::Function, so
// closure_node has type None
// 2. There is no export logic for it yet, so it cannot be
// exported/python_printed
// 3. There is nothing preventing the assignment of already existing variables
// inside the closures
// the changes to those variables will just get forgotten.
// 4. There is no parsing support in frontend.py, this is intentional since it
// prevents people from accidentally using this feature.
std::shared_ptr<ClosureValue> emitClosure(
const std::function<void(Block*)>& emit_body) {
Node* closure_node = graph->insertNode(graph->create(prim::Function, 1));
// it is not a real thing yet, so just say the type is None
closure_node->output()->setType(NoneType::get());
Block* block = closure_node->addBlock();
{
WithInsertPoint guard(block);
pushFrame(block, /*starts_def=*/true);
emit_body(block);
popFrame(/*ends_def=*/true);
}
return std::make_shared<ClosureValue>(closure_node->output());
}
void emitClosure(const Def& def) {
// invoked once the closure block is set as the enviroment
auto emit_body = [&](Block* closure_block) {
emitDef(
def,
nullptr,
closure_block); // ignore schema return, we just wont use it for now
// since we never create a Method for the closure
};
auto closure_value = emitClosure(emit_body);
environment_stack->setSugaredVar(
def.name().range(), def.name().name(), closure_value);
}
void emitBreak(const Break& stmt) {
auto break_node =
graph->create(prim::BreakStmt, {}, 0)->setSourceRange(stmt.range());
graph->insertNode(break_node);
}
void emitContinue(const Continue& stmt) {
auto continue_node =
graph->create(prim::ContinueStmt, {}, 0)->setSourceRange(stmt.range());
graph->insertNode(continue_node);
}
void emitReturn(const Return& stmt) {
Value* result = emitExpr(stmt.expr());
TypePtr result_type = def_stack_.back().declared_return_type_;
// result type is annotated, every return must convert to that type
if (result_type) {
// this guard skips implicit conversion from None -> Tensor for the return
// type. otherwise forgetting a return a function returning a tensor will
// cause a None to be converted to a tensor.
if (!(result_type->isSubtypeOf(TensorType::get()) &&
result->type()->isSubtypeOf(NoneType::get()))) {
result = tryConvertToType(
stmt.range(),
*graph,
result_type,
result,
/*allow_conversions=*/true);
}
if (!result->type()->isSubtypeOf(result_type)) {
throw ErrorReport(stmt.range())
<< "Return value was annotated as having type "
<< result_type->python_str() << " but is actually of type "
<< result->type()->python_str();
}
} else {
result_type = def_stack_.back().merged_return_type_;
if (!result_type) {
result_type = result->type();
}
if (!unifyTypes(result_type, result->type())) {
throw ErrorReport(stmt.range())
<< "Previous return statement returned a value of type "
<< result_type->python_str()
<< " but this return statement returns a value of type "
<< result->type()->python_str();
}
}
AT_ASSERT(result_type);
def_stack_.back().merged_return_type_ = result_type;
graph->insertNode(graph->create(prim::ReturnStmt, {result}, 0));
exit_blocks.insert(environment_stack->block());
}
void emitStatements(
List<Stmt>::const_iterator begin,
List<Stmt>::const_iterator end) {
for (; begin != end; ++begin) {
auto stmt = *begin;
ErrorReport::CallStack::update_pending_range(stmt.range());
switch (stmt.kind()) {
case TK_IF:
emitIf(If(stmt));
break;
case TK_WHILE:
emitWhile(While(stmt));
break;
case TK_FOR:
emitFor(For(stmt));
break;
case TK_ASSIGN:
emitAssignment(Assign(stmt));
break;
case TK_AUG_ASSIGN:
emitAugAssignment(AugAssign(stmt));
break;
case TK_GLOBAL:
for (auto ident : Global(stmt).names()) {
const auto& name = Ident(ident).name();
environment_stack->setVar(
ident.range(), name, graph->addInput(name));
}
break;
case TK_EXPR_STMT: {
auto expr = ExprStmt(stmt).expr();
emitSugaredExpr(expr, 0);
} break;
case TK_RAISE:
emitRaise(Raise(stmt).range());
break;
case TK_ASSERT:
emitAssert(Assert(stmt));
break;
case TK_RETURN: {
emitReturn(Return(stmt));
} break;
case TK_CONTINUE: {
emitContinue(Continue(stmt));
} break;
case TK_BREAK: {
emitBreak(Break(stmt));
} break;
case TK_PASS:
// Emit nothing for pass
break;
case TK_DEF:
emitClosure(Def(stmt));
break;
default:
throw ErrorReport(stmt)
<< "Unrecognized statement kind " << kindToString(stmt.kind());
}
}
}
std::shared_ptr<Environment> emitSingleIfBranch(
Block* b,
const List<Stmt>& branch,
const Refinements& refinements) {
pushFrame(b);
WithInsertPoint guard(b);
insertRefinements(refinements);
emitStatements(branch);
return popFrame();
}
Node* create(Symbol kind, const SourceRange& loc, size_t n_outputs) {
return graph->create(kind, n_outputs)->setSourceRange(loc);
}
Value* emitTernaryIf(const TernaryIf& expr) {
const auto& bool_info = findRefinements(expr.cond());
Value* cond_value = emitCond(expr.cond());
auto true_expr = [&] {
insertRefinements(bool_info.true_refinements_);
return emitExpr(expr.true_expr());
};
auto false_expr = [&] {
insertRefinements(bool_info.false_refinements_);
return emitExpr(expr.false_expr());
};
return emitIfExpr(expr.range(), cond_value, true_expr, false_expr);
}
Value* emitListComprehension(const ListComp& lc) {
// this avoids a race condition where we would re-use the same temp name
static std::atomic<size_t> tmp_count{0};
const auto tmp_name =
std::string("___list_acc") + std::to_string(tmp_count++);
const auto list_value = emitExpr(lc.iter());
if (list_value->type()->kind() != TypeKind::ListType) {
// TODO: constraining iterators to be simple lists for now
// as it makes easy to get list's element type.
throw ErrorReport(lc.range())
<< "iterator expression is expected to be a list";
}
auto elem_types = list_value->type()->containedTypes();
// TODO: users can easily change the type to (x,1) or float(x)
// as in `float(x) for x in my_list_of_ints`
// eventually, we would probably want to temporarily inject x
// so we can evaluate the generator expression (e.g. `float(x)`) depending
// on x
// given `[x*2 for x in my_list]` this generates the following AST:
// __list_acc = []
// for x in my_list:
// __list_acc.append(x*2)
const auto n = graph->insertNode(
graph->createList(elem_types.at(0), at::ArrayRef<Value*>{}));
environment_stack->setVar(lc.range(), tmp_name, n->output());
const auto tmp_list_ident = Ident::create(lc.range(), tmp_name);
const auto tmp_list_var = Var::create(lc.range(), tmp_list_ident);
const auto append_ident = Ident::create(lc.range(), "append");
const auto dot_op = Select::create(lc.range(), tmp_list_var, append_ident);
const auto append_args_list = List<Expr>::create(lc.range(), {lc.elt()});
const auto append_attrs = List<Attribute>::create(lc.range(), {});
const auto apply_append =
Apply::create(lc.range(), dot_op, append_args_list, append_attrs);
const auto expr_stmt = ExprStmt::create(lc.range(), apply_append);
const auto stmt_list = List<Stmt>::create(lc.range(), {expr_stmt});
const auto iters_list = List<Expr>::create(lc.range(), {lc.iter()});
const auto targets_list = List<Expr>::create(lc.range(), {lc.target()});
const auto for_loop =
For::create(lc.range(), targets_list, iters_list, stmt_list);
emitFor(for_loop);
return n->output();
}
// Insert subtyping refinements
void insertRefinements(const Refinements& ref) {
for (const auto& name_mappings : ref.mappings_) {
const std::string& name = name_mappings.first;
auto type = name_mappings.second.first;
const auto& range = *name_mappings.second.second;
Value* v = environment_stack->getVar(name, range);
if (type != NoneType::get()) {
Value* output = graph->insert(prim::unchecked_unwrap_optional, {v});
environment_stack->setVar(range, name, output);
}
// todo @eellison - revisit inserting Nones when None subtypes Optional
}
}
Value* emitShortCircuitIf(
const SourceRange& loc,
const TreeRef& first_expr,
const TreeRef& second_expr,
bool is_or) {
const auto first_bool_info = findRefinements(first_expr);
Value* first_value = emitCond(Expr(first_expr));
// if the second expr in the short circuit is not evaluated,
// than the first expression is False if the short circuit
// is an `and` and True if the short circuit is an `or`.
// `False and expr` -> False, `True or expr` -> True
//
// inserting it as a constant makes optimization easier
Value* first_value_returned;
const Refinements* first_expr_refinements;
const Refinements* second_expr_refinements;
// if it's an OR the first expr is emitted in the true branch
// and the second expr in the false branch, if it's an AND the opposite
if (is_or) {
first_value_returned = graph->insertConstant(true, nullptr, loc);
first_expr_refinements = &first_bool_info.true_refinements_;
second_expr_refinements = &first_bool_info.false_refinements_;
} else {
first_value_returned = graph->insertConstant(false, nullptr, loc);
first_expr_refinements = &first_bool_info.false_refinements_;
second_expr_refinements = &first_bool_info.true_refinements_;
}
auto get_first_expr = [&] {
insertRefinements(*first_expr_refinements);
return first_value_returned;
};
auto get_second_expr = [&] {
insertRefinements(*second_expr_refinements);
return emitCond(Expr(second_expr));
};
// if this is an OR, eval second expression if first expr is False
// If this is an AND, eval second expression if first expr is True
if (is_or) {
return emitIfExpr(loc, first_value, get_first_expr, get_second_expr);
} else {
return emitIfExpr(loc, first_value, get_second_expr, get_first_expr);
}
}
Value* emitIfExpr(
const SourceRange& range,
Value* cond_value,
std::function<Value*()> true_expr,
std::function<Value*()> false_expr) {
Node* n = graph->insertNode(create(prim::If, range, 0));
n->addInput(cond_value);
auto* true_block = n->addBlock();
auto* false_block = n->addBlock();
auto emit_if_expr = [this](Block* b, std::function<Value*()> expr_value) {
pushFrame(b);
WithInsertPoint guard(b);
Value* out_val = expr_value();
b->registerOutput(out_val);
popFrame();
};
emit_if_expr(true_block, std::move(true_expr));
emit_if_expr(false_block, std::move(false_expr));
auto true_type = true_block->outputs().at(0)->type();
auto false_type = false_block->outputs().at(0)->type();
auto unified = unifyTypes(true_type, false_type);
if (!unified) {
throw ErrorReport(range)
<< "if-expression's true branch has type " << true_type->python_str()
<< " but false branch has type " << false_type->python_str();
}
// Add op outputs
auto expr_value = n->addOutput()->setType(*unified); // Resulting value
return expr_value;
}
Value* emitCond(const Expr& cond) {
Value* v = emitExpr(cond);
Value* out;
try {
auto bool_cast = environment_stack->getSugaredVar("bool", cond.range());
out = asSimple(bool_cast->call(cond.get()->range(), method, {v}, {}, 0));
} catch (...) {
throw ErrorReport(cond.range()) << "Could not cast value of type "
<< v->type()->python_str() << " to bool";
}
// cast value not response for checking output type
if (!out->type()->isSubtypeOf(BoolType::get())) {
throw ErrorReport(cond)
<< "expected a bool expression for condition but found "
<< out->type()->python_str();
}
return out;
}
void emitIfElseBlocks(Value* cond_value, const If& stmt) {
Node* n = graph->insertNode(create(prim::If, stmt.range(), 0));
n->addInput(cond_value);
const auto bool_info = findRefinements(stmt.cond());
auto* true_block = n->addBlock();
auto* false_block = n->addBlock();
// Emit both blocks once to get the union of all mutated values
auto save_true = emitSingleIfBranch(
true_block, stmt.trueBranch(), bool_info.true_refinements_);
auto save_false = emitSingleIfBranch(
false_block, stmt.falseBranch(), bool_info.false_refinements_);
bool true_exits = exit_blocks.count(true_block);
bool false_exits = exit_blocks.count(false_block);
if (true_exits && false_exits) {
exit_blocks.insert(n->owningBlock());
}
// In python, every variable assigned in an if statement escapes
// the scope of the if statement (all variables are scoped to the function).
// Script is a subset of python: we consider variables to be in scope
// as long as there is a definition of the variable along all paths
// through the if statemnent
// ----
// if ...:
// a =
// else:
// ...
// ... = a # error, a is not defined along all paths
// ----
// if ...:
// a =
// else:
// a =
// ... = a # OK, a is defined along all paths
// ----
// a = ...
// if ...:
// a =
// ... = a # OK, a is defined along all paths
// if ...:
// a =
// else:
// return
// ... = a # OK, a is always defined
// ordered set, because we want deterministic graph output
std::set<std::string> mutated_variables;
// When we access either the true or false environment,
// we need to set the insertion point so the prim::Load is inserted
// into the right block.
// if var is only defined in one branch save error in case it's used later
for (auto& v : save_true->definedVariables()) {
{
WithInsertPoint insert(false_block);
if (save_false->findInAnyFrame(v) || false_exits) {
mutated_variables.insert(v);
} else {
ErrorReport error(stmt);
environment_stack->setVariableTypeError(v, [=]() -> std::string {
error << v << " is not defined in the false branch";
return error.what();
});
}
}
}
for (auto& v : save_false->definedVariables()) {
{
WithInsertPoint insert(true_block);
if (save_true->findInAnyFrame(v) || true_exits) {
mutated_variables.insert(v);
} else {
ErrorReport error(stmt);
environment_stack->setVariableTypeError(v, [=]() -> std::string {
error << v << " is not defined in the true branch";
return error.what();
});
}
}
}
// Register outputs in each block
for (const auto& x : mutated_variables) {
Value* tv;
Value* fv;
{
WithInsertPoint insert(true_block);
if (!true_exits) {
tv = save_true->getVar(x, stmt.range());
}
}
{
WithInsertPoint insert(false_block);
if (!false_exits) {
fv = save_false->getVar(x, stmt.range());
}
}
// if both branches exit don't emit any variables
// if one branch exits then we allow the all variables in the other branch
// to escape scope since they are well-defined
if (true_exits && false_exits) {
continue;
} else if (true_exits) {
tv = graph->createUninitialized(fv->type())
->insertBefore(true_block->return_node())
->output();
graph->createStore(x, tv)->insertBefore(true_block->return_node());
} else if (false_exits) {
fv = graph->createUninitialized(tv->type())
->insertBefore(false_block->return_node())
->output();
graph->createStore(x, fv)->insertBefore(false_block->return_node());
}
auto unified = unifyTypes(tv->type(), fv->type());
// attempt to unify the types. we allow variables to be set to different
// types in each branch as long as that variable is not already in scope,
// or if that variable does not get used later. here, we save the error
// so that the error message will be more informative in the case that is
// used later. When a is accessed in (a + 1), the error will get printed
// if cond:
// a = 1
// else:
// a = tensor
// b = a + 1
//
if (!unified) {
ErrorReport error(stmt);
error << "Type mismatch: " << x << " is set to type "
<< tv->type()->python_str() << " in the true branch"
<< " and type " << fv->type()->python_str()
<< " in the false branch";
if (save_true->findInParentFrame(x) ||
save_false->findInParentFrame(x)) {
throw error;
} else {
environment_stack->setVariableTypeError(
x, [=]() -> std::string { return error.what(); });
continue;
}
}
environment_stack->setType(x, *unified);
}
}
void emitIf(const If& stmt) {
// NOTE: emitIf checks on If stmt condition to see if the cond AST kind ==
// is/is not, for such cases we do meta programming and disable emitting the
// corresponding branches
Expr cond = stmt.cond();
if (cond.kind() != TK_IS && cond.kind() != TK_ISNOT) {
// emit normal IF stmt for cases except TK_IS and TK_ISNOT
Value* cond_value = emitCond(cond);
emitIfElseBlocks(cond_value, stmt);
return;
}
// meta programming on AST for is/is not cases and emit branches base on the
// possible output of cond
auto cond_op = BinOp(cond);
SugaredValuePtr lhs_val = emitSugaredExpr(cond_op.lhs(), 1);
SugaredValuePtr rhs_val = emitSugaredExpr(cond_op.rhs(), 1);
List<Stmt> always_none_branch =
cond.kind() == TK_IS ? stmt.trueBranch() : stmt.falseBranch();
List<Stmt> never_none_branch =
cond.kind() == TK_IS ? stmt.falseBranch() : stmt.trueBranch();
auto lhs_none = lhs_val->isNone();
auto rhs_none = rhs_val->isNone();
// Dispatch logic (A: ALWAYS, N: NEVER, M: MAYBE):
//
// AA, -> emit always_none_branch
// AN , NA-> emit never_none_branch
// MA, MM, MN, NM, NN, AM -> emit both conditional branches
if (lhs_none == ALWAYS && rhs_none == ALWAYS) {
// None is/is not None: only emit the always_none_branch
emitStatements(always_none_branch);
} else if (
(lhs_none == ALWAYS && rhs_none == NEVER) ||
(lhs_none == NEVER && rhs_none == ALWAYS)) {
// lhs_val/rhs_val with A/M: only emit never_none_branch
emitStatements(never_none_branch);
} else {
// all other cases for lhs_val and rhs_val
// emit the whole If stmt as usual, finish emitCond first
auto lhs_range = cond_op.lhs().get()->range();
auto rhs_range = cond_op.rhs().get()->range();
auto kind = getNodeKind(cond.kind(), cond.get()->trees().size());
Value* cond_value = emitBuiltinCall(
cond.get()->range(),
*method.graph(),
kind,
c10::nullopt,
{lhs_val->asValue(lhs_range, method),
rhs_val->asValue(rhs_range, method)},
{},
/*required=*/true);
emitIfElseBlocks(cond_value, stmt);
}
}
// *********************** Loop Operators ************************************
// Emits a loop operator with the form:
// Loop(max_trip_count)
// block0(loop_counter) {
// <body>
// }
// block1 {
// <loop condition>
// -> (condition)
// }
// For loops will have an empty loop condition block with condition set to
// true. In the convert to ssa pass, the loop condition will correctly
// inlined. and inputs and outputs added so that the loop conforms to the
// semantics specified at
// https://github.com/onnx/onnx/blob/master/docs/Operators.md#Loop
void emitLoopCommon(
SourceRange range,
const List<Stmt>& body,
const SugaredValuePtr& iter_val,
c10::optional<List<Expr>> targets,
c10::optional<Expr> cond) {
Value* max_trip_count_val = nullptr;
if (iter_val != nullptr) {
max_trip_count_val = iter_val->len(range, method);
} else {
max_trip_count_val = materializeConstant(
std::numeric_limits<int64_t>::max(),
*graph,
range,
integral_constants);
}
Node* n = graph->insertNode(create(prim::Loop, range, 0));
auto* body_block = n->addBlock();
{
Block* condition_block = n->addBlock();
pushFrame(condition_block);
Value* out;
if (cond) {
WithInsertPoint insert(condition_block);
out = emitCond(cond.value());
} else {
WithInsertPoint insert(n);
out = graph->insertConstant(true, nullptr, range);
}
condition_block->registerOutput(out);
popFrame();
}
n->addInput(max_trip_count_val);
Value* trip_count =
body_block->addInput()->setType(IntType::get()); // Iteration num
{
pushFrame(body_block);
WithInsertPoint guard(body_block);
// if the FOR iters and targets are present, emit FOR target assignments
if (iter_val != nullptr && targets) {
Value* cur_elem = iter_val->getitem(range, method, trip_count);
SugaredValuePtr sv = std::make_shared<SimpleValue>(cur_elem);
List<Expr> target_exprs = targets.value();
validateAssignLhsExpr(target_exprs, range);
// if target exprs are more than 1, it means iteration unpacking on LHS
// we create Tuple literal to wrap those target exprs for assignments
if (target_exprs.size() > 1) {
Expr tl = TupleLiteral::create(range, target_exprs);
target_exprs = List<Expr>::create(range, {tl});
}
emitExprsAssign(target_exprs, {sv}, range, /*n_binders=*/1);
}
emitStatements(body);
popFrame();
}
}
void emitFor(const For& stmt) {
auto targets = stmt.targets();
auto itrs = stmt.itrs();
auto body = stmt.body();
if (stmt.itrs().size() != 1) {
throw ErrorReport(stmt) << "List of iterables is not supported currently";
}
// Emit loop information for builtinFunction values like range(), zip(),
// enumerate() or SimpleValue like List, Tensor, Dict, etc.
SugaredValuePtr sv = emitSugaredExpr(itrs[0], 1);
// We will get IterableTree for builtinFunctions zip() and enumerate(),
// RangeValue for range(), and SimpleValue for types like
// List/Tensor/Dict/String.
auto range_val = std::dynamic_pointer_cast<RangeValue>(sv);
auto siv = std::dynamic_pointer_cast<SimpleValue>(sv);
auto iterable_tree = std::dynamic_pointer_cast<IterableTree>(sv);
// For SimpleValue(except Tuple) or RanveValue/IterableTree, emit common
// loop
if ((siv && !siv->getValue()->type()->cast<TupleType>()) || range_val ||
iterable_tree) {
// looping over a dict defaults to looping over the keys in python
if (siv && siv->getValue()->type()->cast<DictType>()) {
sv = std::make_shared<SimpleValue>(
graph->insert(aten::keys, {siv->getValue()}, {}, stmt.range()));
}
emitLoopCommon(stmt.range(), body, sv, targets, {});
return;
}
// Emit or unroll the loop for Tuple or ModuleList, we choose to unroll or
// emit each subelemnt for each iteration separately. This is because for
// ModuleList, each module inside the list may be different types, so FOR ..
// in ModuleList essentially should emit different stmts for each iteration,
// which we shouldn't emit the prim::Loop node for it, the same rule applies
// for the Tuple case.
auto instances = sv->asTuple(stmt.range(), method);
pushFrame(environment_stack->block());
for (const auto& inst : instances) {
emitExprsAssign(targets, {inst}, itrs[0].range(), /*n_binders=*/1);
emitStatements(body);
}
for (const auto& n : environment_stack->definedVariables()) {
if (environment_stack->findInParentFrame(n)) {
environment_stack->next->setVar(
stmt.range(), n, environment_stack->getVar(n, stmt.range()));
}
}
popFrame();
}
void emitWhile(const While& stmt) {
auto cond = stmt.cond();
emitLoopCommon(stmt.range(), stmt.body(), nullptr, {}, cond);
}
// Currently we do not support assigning exceptions to variables,
// a = Exception("hi")
// raise a
//
// We ignore the expression following raise
//
// NYI: add exception logic to control-flow nodes
// if True:
// a = 1
// else
// raise Exception("Hi")
// print(a)
void emitRaise(const SourceRange& loc) {
const std::string exception = "Exception";
auto string_input = insertConstant(*graph, exception, nullptr, loc);
graph->insert(prim::RaiseException, {string_input}, {}, loc);
}
void emitAssert(const Assert& stmt) {
Value* cond_value = emitCond(stmt.test());
Node* n = graph->insertNode(create(prim::If, stmt.range(), 0));
n->addInput(cond_value);
/* true_block =*/n->addBlock();
auto* false_block = n->addBlock();
// if assert test is false throw exception
pushFrame(false_block);
WithInsertPoint guard(false_block);
emitRaise(stmt.range());
popFrame();
}
// Validate that the `lhs` Expr's in an assignment statement are valid. That
// is:
//
// 1) All lhs Expr's are either Var, Tuple or Starred nodes
// 2) There is at most one Starred node in the lhs Expr
// 3) A Starred node can only appear when there is another non-Starred lhs
// Expr. Concretely this means that `*abc = func()` is illegal. Unpacking
// all outputs into a tuple is covered by `abc = func()`.
bool validateAssignLhsExpr(const List<Expr>& lhs, const SourceRange& r) {
size_t num_normal_assign = 0;
size_t num_starred = 0;
for (const auto& assignee : lhs) {
if (assignee.kind() == TK_VAR || assignee.kind() == TK_SUBSCRIPT ||
assignee.kind() == TK_TUPLE_LITERAL) {
num_normal_assign++;
} else if (assignee.kind() == TK_STARRED) {
num_starred++;
} else {
throw ErrorReport(assignee) << "lhs of assignment must be a variable, "
<< "subscript, or starred expression";
}
}
if (num_starred > 1) {
throw ErrorReport(r)
<< "Only one starred expression is allowed on the lhs";
}
if (num_starred > 0 && num_normal_assign == 0) {
throw ErrorReport(r) << "A Starred expression may only appear on the "
<< "lhs within the presence of another non-starred"
<< " expression";
}
return num_starred;
}
// Get the appropriate builtin op for this augmented assignment
// If the RHS is a tensor, return the corresponding ATen in-place op
// If it's a list of scalars, then return the corresponding list augment op
Symbol getAugOp(const AugAssign& stmt, const TypePtr& type) {
if (type->cast<ListType>()) { // Lists also have in-place ops.
switch (stmt.aug_op()) {
case '+':
return aten::add_;
}
}
bool isTensor = type->isSubtypeOf(TensorType::get());
switch (stmt.aug_op()) {
case '+':
return isTensor ? aten::add_ : aten::add;
case '-':
return isTensor ? aten::sub_ : aten::sub;
case '/':
return isTensor ? aten::div_ : aten::div;
case '*':
return isTensor ? aten::mul_ : aten::mul;
default:
throw ErrorReport(stmt)
<< "Unknown augmented assignment: " << kindToString(stmt.aug_op());
}
}
// Emit nodes for augmented assignments like `+=`
void emitAugAssignment(const AugAssign& stmt) {
switch (stmt.lhs().kind()) {
case TK_VAR: {
emitAugAssignmentToVar(stmt);
} break;
case '.': {
emitAugAssignmentToSelectVar(stmt);
} break;
case TK_SUBSCRIPT: {
emitAugAssignmentToSubscript(stmt);
} break;
default:
throw ErrorReport(stmt.lhs())
<< "unexpected expression on "
<< "left-hand side of augmented assignment";
}
}
// This will be called when there is a class param or module buffer
// mutation which make the LHS of the expr be a select expression
//
// Example like:
// class A(Module):
// def __init__():
// self.register_buffer("running_var", torch.zeros(1))
//
// def forward():
// self.num_batches += 1
//
// In this case we will only consider the scenario that the module
// buffer type is a tensor, and we emit the corresponding tensor
// in place op, and throw error for other unsupported types
void emitAugAssignmentToSelectVar(const AugAssign& stmt) {
const auto lhs = Select(stmt.lhs());
const auto lhsSugaredVar =
environment_stack->getSugaredVar(Var(lhs.value()).name());
const auto lhsValue =
lhsSugaredVar->attr(lhs.range(), method, lhs.selector().name())
->asValue(lhs.range(), method);
if (lhsValue->type()->isSubtypeOf(TensorType::get())) {
// for module parameter/buffer assignment, only consider tensor types,
// emit the corresponding in-place op
const auto rhs = NamedValue(stmt.rhs().range(), emitExpr(stmt.rhs()));
const auto self = NamedValue(stmt.lhs().range(), "self", lhsValue);
emitBuiltinCall(
stmt.range(),
*method.graph(),
getAugOp(stmt, lhsValue->type()),
self,
{rhs},
{},
/*required=*/true);
} else {
throw ErrorReport(stmt.lhs())
<< "left-hand side of augmented assignment to module "
<< "parameters/buffers can only be tensor types";
}
}
void emitAugAssignmentToVar(const AugAssign& stmt) {
const auto lhs = Var(stmt.lhs());
const auto lhsValue = environment_stack->getSugaredVar(lhs.name())
->asValue(lhs.range(), method);
auto lhsType = lhsValue->type();
if (lhsType->isSubtypeOf(TensorType::get()) ||
lhsType->cast<c10::ListType>()) {
// for tensors, emit the corresponding in-place op
const auto rhs = NamedValue(stmt.rhs().range(), emitExpr(stmt.rhs()));
const auto self = NamedValue(stmt.lhs().range(), "self", lhsValue);
const auto output = emitBuiltinCall(
stmt.range(),
*method.graph(),
getAugOp(stmt, lhsValue->type()),
self,
{rhs},
{},
/*required=*/true);
environment_stack->setVar(lhs.range(), lhs.name().name(), output);
} else {
// for primitive types, desugar into a simple assignment
// e.g. foo += 1 becomes foo.2 = foo + 1
Ident lhs = Var(stmt.lhs()).name();
Expr expr = BinOp::create(
stmt.range(),
stmt.aug_op(),
Var::create(lhs.range(), lhs),
stmt.rhs());
environment_stack->setVar(lhs.range(), lhs.name(), emitExpr(expr));
}
}
void emitAugAssignmentToSubscript(const AugAssign& stmt) {
// Process the base list value
const auto lhs = Subscript(stmt.lhs());
const auto sliceable = emitExpr(lhs.value());
if (sliceable->type()->isSubtypeOf(TensorType::get())) {
// If it's a tensor, just fully evaluate the subscript operation and emit
// an in-place assignment
std::vector<Value*> tensorIndices;
Value* sliced;
std::tie(sliced, tensorIndices) = emitIntAndSliceIndexing(
lhs.range(), sliceable, lhs.subscript_exprs());
const auto slicedArg = NamedValue(stmt.lhs().range(), "self", sliced);
const auto rhs = NamedValue(stmt.rhs().range(), emitExpr(stmt.rhs()));
if (tensorIndices.size() == 0) {
// Common case: we only tried to index with int and slices. Emit the
// correct augmented assignment op to the sliced value
emitBuiltinCall(
stmt.range(),
*method.graph(),
getAugOp(stmt, sliceable->type()),
slicedArg,
{rhs},
{},
/*required=*/true);
} else {
// Special case: we tried to do "advanced indexing". Lower this expr
// into `index` and `index_put_` ops with tensordices of Tensor?[]
const auto indices = graph
->insertNode(graph->createList(
OptionalType::ofTensor(), tensorIndices))
->output();
const auto indexed =
graph->insert(aten::index, {slicedArg, indices}, {}, stmt.range());
const auto augmented = emitBuiltinCall(
stmt.range(),
*method.graph(),
getAugOp(stmt, sliceable->type()),
indexed,
{rhs},
{},
/*required=*/true);
graph->insert(
aten::index_put_,
{slicedArg, indices, augmented},
{},
stmt.range());
}
} else {
// Otherwise, it should be a list. Lower this expression into:
// list.set_item(get_item(idx).add_(value))
// similar to how Python handles things.
const auto listType = sliceable->type()->cast<ListType>();
AT_ASSERT(listType != nullptr);
auto elementType = listType->getElementType();
// Get the idx to augment
const auto subscriptExprs = lhs.subscript_exprs();
if (subscriptExprs.size() != 1) {
throw ErrorReport(subscriptExprs)
<< "Sliced expression not yet supported for"
<< " subscripted list augmented assignment. "
<< "File a bug if you want this";
}
const auto idxValue = emitExpr(subscriptExprs[0]);
const auto listArg = NamedValue(lhs.value().range(), "list", sliceable);
const auto idxArg = NamedValue(subscriptExprs.range(), "idx", idxValue);
const auto valueArg =
NamedValue(stmt.rhs().range(), "value", emitExpr(stmt.rhs()));
const auto getItem =
graph->insert(aten::__getitem__, {listArg, idxArg}, {}, stmt.range());
const auto augmentedItem = graph->insert(
getAugOp(stmt, elementType), {getItem, valueArg}, {}, stmt.range());
graph->insert(
aten::_set_item, {listArg, idxArg, augmentedItem}, {}, stmt.range());
}
}
// Emit mutating assignments like `foo[0] = bar`
void emitSubscriptAssign(
const SourceRange& stmtRange,
const Subscript& lhs,
const Expr& rhs) {
emitSubscriptAssign(stmtRange, lhs, NamedValue(rhs.range(), emitExpr(rhs)));
}
void emitSubscriptAssign(
const SourceRange& stmtRange,
const Subscript& lhs,
const NamedValue& rhs) {
// First check the base value.
auto sliceable = emitExpr(lhs.value());
// If it's a tensor, copy the RHS data into it
if (sliceable->type()->isSubtypeOf(TensorType::get())) {
std::vector<Value*> tensorIndices;
Value* sliced;
// Handle multi-dimensional slicing: first emit int/slice indexing
// TODO: the Python equivalent code has special-cased copy_to
// broadcasting to match NumPy semantics (see PR#4853). We can't
// replicate that without knowing the size of the Tensor; so really that
// code should be moved into the aten function
std::tie(sliced, tensorIndices) = emitIntAndSliceIndexing(
lhs.range(), sliceable, lhs.subscript_exprs());
const auto slicedArg = NamedValue(lhs.range(), sliced);
if (tensorIndices.size() == 0) {
// Common case: we only tried to index with int and slices. Copy the
// RHS into the resulting tensor.
graph->insert(aten::copy_, {slicedArg, rhs}, {}, stmtRange);
} else {
// Special case: we tried to do "advanced indexing" with a tensor.
// Dispatch to `aten::index_put_` with tensorindices of Tensor?[]
const auto indices = graph
->insertNode(graph->createList(
OptionalType::ofTensor(), tensorIndices))
->output();
graph->insert(
aten::index_put_, {slicedArg, indices, rhs}, {}, stmtRange);
}
// Otherwise, this is a list. Dispatch to aten::_set_item to both select
// and assign
} else {
const auto subscript = lhs.subscript_exprs();
if (subscript.size() != 1 || subscript[0].kind() == TK_SLICE_EXPR) {
throw ErrorReport(subscript)
<< "Sliced expression not yet supported for"
<< " subscripted list assignment. "
<< "File a bug if you want this";
}
std::vector<NamedValue> args;
args.emplace_back(lhs.value().range(), "list", sliceable);
args.emplace_back(
lhs.subscript_exprs().range(), "idx", emitExpr(subscript[0]));
args.push_back(rhs);
graph->insert(aten::_set_item, args, {}, stmtRange);
}
}
void emitTupleAssign(const TupleLiteral& tl, const Expr& rhs) {
size_t n_binders = tl.inputs().size();
bool starred_unpack = validateAssignLhsExpr(tl.inputs(), tl.range());
if (starred_unpack)
n_binders--;
auto output = emitSugaredExpr(rhs, n_binders);
emitTupleAssign(tl, output, rhs.range(), n_binders, starred_unpack);
}
void emitTupleAssign(
const TupleLiteral& tl,
const SugaredValuePtr& rhs_output,
const SourceRange& rhs_loc,
size_t n_binders,
bool starred_unpack) {
auto outputs = rhs_output->asTuple(
rhs_loc,
method,
starred_unpack ? c10::nullopt : c10::optional<size_t>{n_binders});
if (outputs.size() < n_binders) {
throw ErrorReport(tl)
<< "need " << (starred_unpack ? "at least " : "") << n_binders
<< " values to unpack but found only " << outputs.size();
}
if (outputs.size() > n_binders && !starred_unpack) {
throw ErrorReport(tl) << "too many values to unpack: need " << n_binders
<< " but found " << outputs.size();
}
emitExprsAssign(tl.inputs(), outputs, rhs_loc, n_binders);
}
void emitExprsAssign(
const List<Expr>& lhs_exprs,
const at::ArrayRef<SugaredValuePtr> outputs,
const SourceRange& rhs_loc,
size_t n_binders) {
int i = 0;
for (auto assignee : lhs_exprs) {
switch (assignee.kind()) {
case TK_SUBSCRIPT:
emitSubscriptAssign(
rhs_loc,
Subscript(assignee),
NamedValue(rhs_loc, outputs.at(i)->asValue(rhs_loc, method)));
i++;
break;
case TK_VAR:
environment_stack->setSugaredVar(
assignee.range(), Var(assignee).name().name(), outputs.at(i));
i++;
break;
case TK_STARRED: {
auto var = Starred(assignee).expr();
if (var.kind() != TK_VAR) {
throw ErrorReport(var) << "Cannot pack a tuple into a non-variable";
}
size_t n_matched = outputs.size() - n_binders;
ArrayRef<std::shared_ptr<SugaredValue>> outputs_ref = outputs;
auto values = fmap(
outputs_ref.slice(i, n_matched),
[&](const std::shared_ptr<SugaredValue>& v) {
return v->asValue(assignee.range(), method);
});
auto tup = graph->insertNode(graph->createTuple(values))->output();
environment_stack->setVar(var.range(), Var(var).name().name(), tup);
i += n_matched;
} break;
case TK_TUPLE_LITERAL: {
// recursively emit tuple assignments on tuple literal input
TupleLiteral sub_tl = TupleLiteral(assignee);
size_t sub_n_binders = sub_tl.inputs().size();
bool sub_starred_unpack =
validateAssignLhsExpr(sub_tl.inputs(), sub_tl.range());
if (sub_starred_unpack)
sub_n_binders--;
emitTupleAssign(
sub_tl,
outputs.at(i),
rhs_loc,
sub_n_binders,
sub_starred_unpack);
i++;
} break;
default:
throw ErrorReport(assignee)
<< "unexpected expression on the left-hand side";
}
}
}
void emitAssignment(const Assign& stmt) {
if (!stmt.rhs().present()) {
throw ErrorReport(stmt.range())
<< "For an assignment, expected an expression on the right-hand side";
}
const Expr& rhs = stmt.rhs().get();
switch (stmt.lhs().kind()) {
case TK_VAR: {
auto v = Var(stmt.lhs());
TypePtr type = nullptr;
if (stmt.type().present()) {
type = typeParser_.parseTypeFromExpr(stmt.type().get());
}
environment_stack->setSugaredVar(
v.range(), v.name().name(), emitSugaredExpr(rhs, 1, type));
} break;
case TK_TUPLE_LITERAL:
emitTupleAssign(TupleLiteral(stmt.lhs()), rhs);
break;
case '.':
emitSelectAssign(stmt);
break;
case TK_SUBSCRIPT:
emitSubscriptAssign(stmt.range(), Subscript(stmt.lhs()), rhs);
break;
default:
throw ErrorReport(stmt.lhs())
<< "unexpected expression on left-hand side of assignment";
}
}
void emitSelectAssign(const Assign& stmt) {
if (!stmt.rhs().present()) {
throw ErrorReport(stmt.range()) << "Expected RHS for assignment";
}
const auto lhs = Select(stmt.lhs());
const auto basename = Var(lhs.value()).name();
const auto rhsValue = emitSugaredExpr(stmt.rhs().get(), 1)
->asValue(stmt.rhs().range(), method);
auto userObject = environment_stack->getSugaredVar(basename);
userObject->setAttr(stmt.range(), method, lhs.selector().name(), rhsValue);
}
NodeKind getNodeKind(int kind, int ninputs) {
switch (kind) {
case '+':
return aten::add;
case '-':
return aten::sub;
case TK_UNARY_MINUS:
return aten::neg;
case '*':
return aten::mul;
case TK_POW:
return aten::pow;
case '@':
return aten::matmul;
case TK_STARRED:
return prim::Starred;
case '/':
return aten::div;
case '%':
return aten::remainder;
case TK_NE:
return aten::ne;
case TK_EQ:
return aten::eq;
case '<':
return aten::lt;
case '>':
return aten::gt;
case TK_LE:
return aten::le;
case TK_GE:
return aten::ge;
case TK_AND:
return aten::__and__;
case TK_OR:
return aten::__or__;
case TK_IS:
return aten::__is__;
case TK_ISNOT:
return aten::__isnot__;
case TK_NOT:
return aten::__not__;
case TK_FLOOR_DIV:
return aten::floordiv;
case '&':
return aten::__and__;
case '|':
return aten::__or__;
case '^':
return aten::__xor__;
case TK_IN:
return aten::__contains__;
default:
throw std::runtime_error("unknown kind " + std::to_string(kind));
}
}
std::string getOperatorOverload(int kind, int ninputs) {
switch (kind) {
case '+':
return "__add__";
case '-':
return "__sub__";
case TK_UNARY_MINUS:
return "__neg__";
case '*':
return "__mul__";
case TK_POW:
return "__pow__";
case '/':
return "__truediv__";
case '%':
return "__mod__";
case TK_NE:
return "__ne__";
case TK_EQ:
return "__eq__";
case '<':
return "__lt__";
case '>':
return "__gt__";
case TK_LE:
return "__le__";
case TK_GE:
return "__ge__";
case '&':
return "__and__";
case '|':
return "__or__";
case '^':
return "__xor__";
case TK_IN:
return "__contains__";
default:
throw std::runtime_error("unknown kind " + std::to_string(kind));
}
}
std::vector<NamedValue> getNamedValues(
const TreeList& trees,
bool maybe_unpack) {
std::vector<NamedValue> values;
for (const auto& tree : trees) {
if (maybe_unpack && tree->kind() == TK_STARRED) {
auto starred = Starred(tree);
auto entries = emitSugaredExpr(starred.expr(), 1)
->asTuple(starred.range(), method);
for (const auto& entry : entries) {
values.emplace_back(
tree->range(), entry->asValue(starred.range(), method));
}
} else {
values.emplace_back(tree->range(), emitExpr(Expr(tree)));
}
}
return values;
}
std::vector<NamedValue> getNamedValues(
const List<Expr>& trees,
bool maybe_unpack) {
return getNamedValues(trees.tree()->trees(), maybe_unpack);
}
std::vector<Value*> getValues(const TreeList& trees, bool maybe_unpack) {
return toValues(*graph, getNamedValues(trees, maybe_unpack));
}
std::vector<Value*> getValues(const List<Expr>& trees, bool maybe_unpack) {
return getValues(trees.tree()->trees(), maybe_unpack);
}
std::vector<NamedValue> emitAttributes(const List<Attribute>& attributes) {
return fmap(attributes, [&](const Attribute& attr) {
return NamedValue(
attr.range(), attr.name().name(), emitExpr(attr.value()));
});
}
void checkApplyExpr(
Apply& apply,
SourceRange& loc,
size_t expected_inputs = 2) {
if (apply.inputs().size() != expected_inputs) {
throw ErrorReport(loc)
<< Var(apply.callee()).name().name() << " expected exactly "
<< expected_inputs << " arguments but found "
<< apply.inputs().size();
}
if (apply.attributes().size() > 0) {
throw ErrorReport(loc)
<< Var(apply.callee()).name().name() << " takes no keyword arguments";
}
}
std::shared_ptr<SugaredValue> emitApplyExpr(Apply& apply, size_t n_binders) {
auto sv = emitSugaredExpr(apply.callee(), 1);
auto loc = apply.callee().range();
if (auto fork_value = dynamic_cast<ForkValue*>(sv.get())) {
auto& trees = apply.inputs().tree()->trees();
if (trees.size() < 1) {
throw ErrorReport(loc) << "Expected at least one argument to fork()";
}
auto forked = emitSugaredExpr(Expr(trees[0]), 1);
TreeList sliced_trees(trees.begin() + 1, trees.end());
auto inputs = getNamedValues(sliced_trees, true);
auto attributes = emitAttributes(apply.attributes());
return emitForkExpr(loc, forked, inputs, attributes);
} else if (auto annotate_value = dynamic_cast<AnnotateValue*>(sv.get())) {
checkApplyExpr(apply, loc);
TypePtr type = typeParser_.parseTypeFromExpr(apply.inputs()[0]);
Value* expr = tryConvertToType(
apply.range(),
*graph,
type,
emitExpr(apply.inputs()[1], type),
/*allow_conversions=*/true);
// This is to ensure even if user forgets to call annotate None with the
// Optional wrapper type, we still generate the correct value with the
// Optional type. e.g. it makes annoate(Tensor, None) to behave the same
// with annotate(Optional[Tensor], None). It also maintains the backward
// compatibility of exported model on Optional undefined tensor/None
auto opt_type = expr->type()->cast<OptionalType>();
bool forget_opt_annotate =
opt_type && *opt_type->getElementType() == *type;
if (!forget_opt_annotate && !expr->type()->isSubtypeOf(type)) {
throw ErrorReport(apply.inputs())
<< "expected an expression of type " << type->python_str()
<< " but found " << expr->type()->python_str();
}
return std::make_shared<SimpleValue>(expr);
} else if (auto getattr = dynamic_cast<GetAttrValue*>(sv.get())) {
checkApplyExpr(apply, loc);
auto obj = emitSugaredExpr(apply.inputs()[0], 1);
auto selector = apply.inputs()[1];
if (selector.kind() != TK_STRINGLITERAL) {
throw ErrorReport(loc)
<< "getattr's second argument must be a string literal";
}
const std::string& name = StringLiteral(selector).text();
return obj->attr(apply.range(), method, name);
} else if (
auto uninitialized_value =
dynamic_cast<UninitializedValue*>(sv.get())) {
checkApplyExpr(apply, loc, 1);
TypePtr type = typeParser_.parseTypeFromExpr(apply.inputs()[0]);
auto out = graph->insertNode(graph->createUninitialized(type))
->setSourceRange(loc);
return std::make_shared<SimpleValue>(out->output());
} else if (auto isinstance = dynamic_cast<IsInstanceValue*>(sv.get())) {
// NOTE: for `isinstance` builtin call in JIT, we only check the static
// types on the inputs to evaluate, and insert the corresponding constant
// node
std::function<bool(Expr, Expr)> isInstanceCheck = [&](Expr obj,
Expr classinfo) {
if (classinfo.kind() == TK_TUPLE_LITERAL) {
// handle the case for recursive tuple classinfo
// return true if obj is an instance of any of the types
for (Expr e : TupleLiteral(classinfo).inputs()) {
if (isInstanceCheck(obj, e)) {
return true;
}
}
return false;
}
auto type_name = typeParser_.parseBaseTypeName(classinfo);
if (!type_name) {
throw ErrorReport(classinfo.range())
<< "type must be a type identifier";
}
auto val = emitExpr(obj);
// Special casing for list and tuple since isinstance(x, list) and
// isinstance(x, tuple) does not accept List[int] / Tuple[int] like
// subscript type annotation in python
if (*type_name == "list" && val->type()->cast<ListType>()) {
return true;
} else if (*type_name == "tuple" && val->type()->cast<TupleType>()) {
return true;
} else if (val->type()->cast<OptionalType>()) {
throw ErrorReport(loc)
<< "Optional isinstance check is not supported, "
<< "consider use is/isnot None instead";
} else {
TypePtr type = typeParser_.parseTypeFromExpr(classinfo);
if (val->type()->isSubtypeOf(type)) {
return true;
}
}
return false;
};
checkApplyExpr(apply, loc);
bool is_instance_val =
isInstanceCheck(apply.inputs()[0], apply.inputs()[1]);
return std::make_shared<SimpleValue>(
graph->insertConstant(is_instance_val, nullptr, loc));
} else if (auto classNew = dynamic_cast<ClassNewMethod*>(sv.get())) {
if (apply.inputs().size() != 1) {
throw ErrorReport(loc) << "Only one argument to __new__ allowed";
}
auto arg = emitSugaredExpr(apply.inputs()[0], 1);
auto class_arg = dynamic_cast<ClassValue*>(arg.get());
if (!class_arg) {
throw ErrorReport(loc)
<< "Expected class value as argument to __new__, got "
<< arg->kind() << " instead";
}
if (class_arg->type_ != classNew->type_) {
throw ErrorReport(loc)
<< "Argument to __new__() must match the class "
<< "you are calling __new__() on. "
<< "Got: " << class_arg->type_->python_str()
<< ", expected: " << classNew->type_->python_str();
}
return classNew->createObject(apply.range(), method);
} else if (auto iterable = std::dynamic_pointer_cast<IterableValue>(sv)) {
return emitIterableTree(loc, apply.inputs(), iterable);
} else {
auto inputs = getNamedValues(apply.inputs(), true);
auto attributes = emitAttributes(apply.attributes());
return sv->call(loc, method, inputs, attributes, n_binders);
}
}
BoolInfo findRefinements(const TreeRef& tree) {
switch (tree->kind()) {
case TK_IS:
case TK_ISNOT: {
const auto& inputs = tree->trees();
if (inputs.at(0)->kind() == TK_VAR && inputs.at(1)->kind() == TK_NONE) {
const std::string& var_name = Var(inputs[0]).name().name();
Refinements true_info, false_info;
auto type =
environment_stack->getVar(var_name, inputs[0]->range())->type();
if (auto opt_type = type->cast<OptionalType>()) {
false_info.setRefinement(
var_name,
TypeAndRange(opt_type->getElementType(), &tree->range()));
true_info.setRefinement(
var_name, TypeAndRange(NoneType::get(), &tree->range()));
}
if (tree->kind() == TK_IS) {
return BoolInfo(true_info, false_info);
} else {
return BoolInfo(false_info, true_info);
}
}
} break;
case TK_NOT: {
const auto& inputs = tree->trees();
auto bool_info = findRefinements(inputs[0]);
return BoolInfo(
bool_info.false_refinements_, bool_info.true_refinements_);
}
case TK_OR:
case TK_AND: {
const auto& inputs = tree->trees();
auto first = findRefinements(inputs[0]);
auto second = findRefinements(inputs[1]);
if (tree->kind() == TK_OR) {
return *first.mergeOr(second);
} else {
return *first.mergeAnd(second);
}
}
}
return BoolInfo();
}
Value* emitExpr(const Expr& tree, const TypePtr& type_hint = nullptr) {
// Push the source range of a call in case compiling this function
// triggers an error
ErrorReport::CallStack::update_pending_range(tree.range());
return emitSugaredExpr(tree, 1, type_hint)->asValue(tree.range(), method);
}
NodeKind reverseComparision(NodeKind kind) {
if (kind == aten::lt) {
return aten::gt;
} else if (kind == aten::le) {
return aten::ge;
} else if (kind == aten::gt) {
return aten::lt;
} else if (kind == aten::ge) {
return aten::le;
}
throw std::runtime_error(
"reverseComparision: unsupported NodeKind. File a bug");
}
// any expression that can produce a SugaredValue is handled here
// expressions that only return a single Value* are handled in emitSimpleExpr
// type_hint is set if there is a type that this value is expected to be
// e.g. a : List[int] = []
// or a = torch.jit.annotate(List[int], [])
// the caller is responsible for checking that the result matches type_hint
// emitSugaredExpr is free to ignore it.
std::shared_ptr<SugaredValue> emitSugaredExpr(
const Expr& tree,
size_t n_binders,
const TypePtr& type_hint = nullptr) {
switch (tree.kind()) {
case TK_VAR:
return environment_stack->getSugaredVar(Var(tree).name());
case '.': {
auto select = Select(tree);
auto sv = emitSugaredExpr(select.value(), 1);
return sv->attr(select.range(), method, select.selector().name());
}
case TK_APPLY: {
auto apply = Apply(tree);
return emitApplyExpr(apply, n_binders);
} break;
default:
return std::make_shared<SimpleValue>(emitSimpleExpr(tree, type_hint));
}
}
Value* emitNegate(const TreeRef& tree) {
const auto& inputs = tree->trees();
auto named_values = getNamedValues(inputs, /*maybe_unpack=*/false);
auto neg_val =
asSimple(makeMagic(
"__neg__",
std::make_shared<BuiltinFunction>(aten::neg, at::nullopt))
->call(tree->range(), method, named_values, {}, 0));
// if we emitted a aten::neg and not some other overloaded function,
// then try to constantfold
if (neg_val->node()->kind() != aten::neg) {
return neg_val;
}
auto maybe_constant_input = toIValue(neg_val->node()->input());
if (!maybe_constant_input) {
return neg_val;
}
auto op = getOperation(neg_val->node());
Stack stack;
stack.push_back(*maybe_constant_input);
op(stack);
AT_ASSERT(stack.size() == 1);
return graph->insertConstant(stack[0], nullptr, tree->range());
}
// We construct the iterable tree here using the IterableTree SugaredValue,
// The tree consists of SimpleValue, RangeValue or IterableValue:
// For SimpleValues(List, Dict, etc) or RangeValue. We will make them as tree
// leaves since we could get the loop information from len() and get_item().
// For IterableValue like zip(), enumerate(), we can model them as a
// combination of leaves, and we emit a IterableTree value to record the tree
// information
SugaredValuePtr emitIterableTree(
SourceRange& loc,
const List<Expr>& inputs,
const std::shared_ptr<IterableValue>& iterable) {
std::shared_ptr<IterableTree> iterable_tree = nullptr;
size_t input_size = inputs.size();
// Handling different iterable values
if (iterable->symbol_ == prim::range) {
std::vector<Value*> input_vals = getValues(inputs, /*maybe_unpack=*/true);
return std::make_shared<RangeValue>(loc, method, input_vals);
} else if (iterable->symbol_ == prim::enumerate) {
// enumerate(x) can be rewrite as subtrees:
// IterableTree(RangeValue(0, math.inf), SimpleValue(x))
Value* start_index = nullptr;
if (input_size == 0) {
throw ErrorReport(loc)
<< "enumerate expected at least 1 arguments, got 0";
}
if (input_size == 2) {
start_index = emitSugaredExpr(inputs[1], 1)->asValue(loc, method);
}
if (input_size > 2) {
throw ErrorReport(loc)
<< "enumerate expected at most 2 arguments, got " << input_size;
}
std::vector<Value*> range_inputs;
if (start_index != nullptr) {
range_inputs.emplace_back(start_index);
}
Value* end = materializeConstant(
std::numeric_limits<int64_t>::max(), *graph, loc, integral_constants);
range_inputs.emplace_back(end);
SugaredValuePtr range_sv =
std::make_shared<RangeValue>(loc, method, range_inputs);
SugaredValuePtr expr_sv = emitSugaredExpr(inputs[0], 1);
iterable_tree = std::make_shared<IterableTree>(
std::vector<SugaredValuePtr>({range_sv, expr_sv}));
} else if (iterable->symbol_ == prim::zip) {
// zip(x, y) can be rewrite as subtrees:
// IterableTree(IterableTree(x), IterableTree(y))
if (inputs.size() == 0) {
throw ErrorReport(loc) << "zip expected at least 1 arguments, got 0";
}
iterable_tree = std::make_shared<IterableTree>();
for (Expr expr : inputs) {
auto expr_sv = emitSugaredExpr(expr, 1);
iterable_tree->addChild(expr_sv);
}
}
return iterable_tree;
}
std::shared_ptr<SugaredValue> emitForkExpr(
SourceRange loc,
const std::shared_ptr<SugaredValue>& forked,
at::ArrayRef<NamedValue> inputs,
at::ArrayRef<NamedValue> attributes) {
auto g = method.graph();
Node* fork_node;
TypePtr out_type;
fork_node = g->insertNode(method.graph()->create(prim::forkClosure, 1))
->setSourceRange(loc);
// We create a fork by emitting a closure and setting the closure output
// into the fork input. If a closure doesn't already exist, we create one.
{
WithInsertPoint insert(fork_node);
if (ClosureValue* sv = dynamic_cast<ClosureValue*>(forked.get())) {
Value* closure_output = sv->asValue(loc, method);
Block* closure_block = closure_output->node()->blocks().at(0);
TORCH_INTERNAL_ASSERT(closure_block->outputs().size() == 1);
out_type = closure_block->outputs().at(0)->type();
fork_node->addInput(closure_output);
} else {
auto emit_closure_body = [&](Block* closure_block) {
auto fn_sugared_output =
forked->call(loc, method, inputs, attributes, 1);
auto fn_simple_output = fn_sugared_output->asValue(loc, method);
closure_block->registerOutput(fn_simple_output);
out_type = fn_simple_output->type();
};
auto closure_value = emitClosure(emit_closure_body);
fork_node->addInput(closure_value->asValue(loc, method));
}
}
Value* node_output =
fork_node->output()->setType(FutureType::create(out_type));
return std::make_shared<SimpleValue>(node_output);
}
Value* emitSimpleExpr(
const TreeRef& tree,
const TypePtr& type_hint = nullptr) {
switch (tree->kind()) {
case TK_IS:
case TK_ISNOT:
case TK_FLOOR_DIV:
case '@': {
const auto& inputs = tree->trees();
auto kind = getNodeKind(tree->kind(), inputs.size());
auto named_values = getNamedValues(inputs, /*maybe_unpack=*/false);
return emitBuiltinCall(
tree->range(),
*method.graph(),
kind,
c10::nullopt,
named_values,
{},
/*required=*/true);
}
case TK_IN:
case TK_POW:
case TK_NE:
case TK_EQ:
case '<':
case '>':
case TK_LE:
case TK_GE:
case '*':
case '/':
case '+':
case '-':
case '%':
case '&':
case '|':
case '^': {
const auto& inputs = tree->trees();
auto kind = getNodeKind(tree->kind(), inputs.size());
auto overload = getOperatorOverload(tree->kind(), inputs.size());
auto named_values = getNamedValues(inputs, /*maybe_unpack=*/false);
if (tree->kind() == TK_IN) {
// For `in` the arguments are in reverse order (the object being
// checked is second)
std::iter_swap(named_values.begin() + 0, named_values.begin() + 1);
}
return asSimple(
makeMagic(
overload, std::make_shared<BuiltinFunction>(kind, at::nullopt))
->call(tree->range(), method, named_values, {}, 0));
}
case TK_NOT: {
Value* input = emitCond(Expr(tree->trees()[0]));
return emitBuiltinCall(
tree->range(),
*method.graph(),
aten::__not__,
c10::nullopt,
{input},
{},
/*required=*/true);
}
case TK_UNARY_MINUS: {
return emitNegate(tree);
}
case TK_AND:
case TK_OR: {
const auto& inputs = tree->trees();
return emitShortCircuitIf(
tree->range(), inputs[0], inputs[1], tree->kind() == TK_OR);
}
case TK_STARRED: {
throw ErrorReport(tree)
<< "Unexpected starred expansion. File a bug report";
}
case TK_CONST: {
return emitConst(Const(tree));
} break;
case TK_TRUE: {
return graph->insertConstant(true, nullptr, tree->range());
} break;
case TK_FALSE: {
return graph->insertConstant(false, nullptr, tree->range());
} break;
case TK_NONE: {
// A None can be inserted even if the type_hint is not an Optional or
// None (e.g. `torch.jit.annotate(Tensor, None)`)
TypePtr hint = type_hint;
if (hint != nullptr && !hint->isSubtypeOf(NoneType::get()) &&
hint->kind() != TypeKind::OptionalType) {
// Implicitly wrap in an Optional if necessary
hint = OptionalType::create(hint);
}
return graph->insertConstant(IValue(), hint, tree->range());
} break;
case TK_SUBSCRIPT: {
return emitSubscript(Subscript(tree));
} break;
case TK_IF_EXPR: {
return emitTernaryIf(TernaryIf(tree));
} break;
case TK_STRINGLITERAL: {
return emitStringLiteral(StringLiteral(tree));
} break;
case TK_LIST_LITERAL: {
auto ll = ListLiteral(tree);
auto values = getValues(ll.inputs(), /*maybe_unpack=*/true);
// determine the element type of the list
// if we have a type hint of List[T], use T
// if the list is non-empty use type_of(list[0])
// otherwise assume it is List[Tensor]
TypePtr elem_type = TensorType::get();
if (type_hint && type_hint->kind() == TypeKind::ListType) {
elem_type = type_hint->expect<ListType>()->getElementType();
} else if (!values.empty()) {
elem_type = values.at(0)->type();
}
// Tensors are special because they have dymnamic properties. So any
// list containing tensors should be typed with the unified typeof all
// the elements.
if (elem_type->isSubtypeOf(TensorType::get())) {
for (const auto& value : values) {
elem_type = unifyTypes(elem_type, value->type()).value();
}
}
for (auto v : values) {
if (!v->type()->isSubtypeOf(elem_type)) {
throw ErrorReport(tree)
<< "Lists must contain only a single type, expected: "
<< *elem_type << " but found " << *v->type() << " instead";
}
}
Value* result =
graph->insertNode(graph->createList(elem_type, values))->output();
return result;
} break;
case TK_TUPLE_LITERAL: {
auto ll = TupleLiteral(tree);
auto values = getValues(ll.inputs(), /*maybe_unpack=*/true);
return graph->insertNode(graph->createTuple(values))->output();
} break;
case TK_DICT_LITERAL: {
auto dl = DictLiteral(tree);
auto key_trees = dl.key_inputs().tree()->trees();
auto value_trees = dl.value_inputs().tree()->trees();
AT_ASSERT(key_trees.size() == value_trees.size());
std::vector<Value*> keys, values;
for (size_t i = 0; i < key_trees.size(); ++i) {
keys.push_back(emitExpr(Expr(key_trees[i])));
values.push_back(emitExpr(Expr(value_trees[i])));
}
TypePtr key_type = nullptr;
TypePtr value_type = nullptr;
if (type_hint && type_hint->kind() == TypeKind::DictType) {
auto dict_type = type_hint->expect<DictType>();
key_type = dict_type->getKeyType();
value_type = dict_type->getValueType();
} else if (!keys.empty()) {
key_type = keys.at(0)->type();
value_type = values.at(0)->type();
} else {
key_type = StringType::get();
value_type = TensorType::get();
}
AT_ASSERT(key_type != nullptr && value_type != nullptr);
return graph
->insertNode(graph->createDict(key_type, value_type, keys, values))
->output();
} break;
case TK_LIST_COMP: {
auto lc = ListComp(tree);
return emitListComprehension(lc);
} break;
default:
throw ErrorReport(tree) << "Cannot emit expr for: " << tree;
}
}
Value* emitConst(const Const& c) {
if (c.isFloatingPoint())
return materializeConstant(
c.asFloatingPoint(), *graph, c.range(), fp_constants);
else
return materializeConstant(
c.asIntegral(), *graph, c.range(), integral_constants);
}
Value* emitStringLiteral(const StringLiteral& c) {
return insertConstant(*graph, c.text(), nullptr, c.range());
}
// Desugars select indexing: tensor[i] -> tensor.select(dim, i)
Value* emitSelect(
const SourceRange& loc,
Value* input,
Value* dim,
Value* index) {
return emitBuiltinCall(
loc, *graph, aten::select, c10::nullopt, {input, dim, index}, {}, true);
}
// Desugars slice indexing: tensor[begin:end] -> tensor.slice(dim, begin, end,
// 1)
Value* emitSlice(
const SourceRange& loc,
Value* input,
Value* dim, // Only used for tensor slicing
const SliceExpr& slice) {
std::vector<NamedValue> args;
args.reserve(4);
args.emplace_back(loc, "self", input);
// XXX: If list slicing becomes more complicated or stops using
// aten::slice, we should separate it from this function.
if (dim) {
AT_ASSERT(input->type()->isSubtypeOf(TensorType::get()));
args.emplace_back(dim);
} else {
AT_ASSERT(!input->type()->isSubtypeOf(TensorType::get()));
}
args.emplace_back(loc, "begin", emitExpr(Expr(slice.startOr(0))));
const auto has_end = slice.end().present();
if (has_end) {
args.emplace_back(loc, "end", emitExpr(Expr(slice.end().get())));
}
if (input->type()->cast<TupleType>()) {
auto has_step = slice.step().present();
if (has_step) {
// TODO: add support for slicing tuples with a step
throw ErrorReport(loc)
<< "Unsupported operation: slicing tuples with a step isn't supported";
}
if (has_end) {
return emitTupleSlice(loc, args[0], args[1], /*end*/ args[2]);
} else {
return emitTupleSlice(loc, args[0], args[1], c10::nullopt);
}
}
auto step = emitExpr(Expr(slice.stepOr(1)));
NamedValue step_nv = NamedValue(loc, "step", step);
return emitBuiltinCall(
loc, *graph, aten::slice, c10::nullopt, args, {step_nv}, true);
}
Value* emitUnsqueeze(const SourceRange& loc, Value* input, Value* dim_val) {
return emitBuiltinCall(
loc, *graph, aten::unsqueeze, c10::nullopt, {input, dim_val}, {}, true);
}
Value* emitIndex(
const SourceRange& loc,
Value* input,
at::ArrayRef<Value*> indices) {
// NB: the index of aten::index should be a type of List[Optional[Tensor]],
// this is to support the case like t[:, :, 1] where : here indicates a
// None/undefined tensor(optional tensor)
auto* index =
graph->insertNode(graph->createList(OptionalType::ofTensor(), indices))
->output();
return emitBuiltinCall(
loc, *graph, aten::index, c10::nullopt, {input, index}, {}, true);
}
// Emits multidimensional slicing with int and slice indices.
// Returns:
// - Value*: the input after it has been indexed by int and slice indices.
// - vector<Value*>: A list of tensor Value* indices that have not been
// applied yet.
// Should be NULL at indices where sliceable (post-slicing) isn't indexed by
// a tensor.
std::pair<Value*, std::vector<Value*>> emitIntAndSliceIndexing(
const SourceRange& loc,
Value* sliceable,
const List<Expr>& subscript_exprs) {
// Overall, to handle indexing (other than Tensors), we need to handle a
// couple different things. For example, for x[1:3, None, 4], each of these
// different index types (slice, None, and integer) result in different
// number of dimensions. Slicing doesn't change the number of dimensions,
// None adds a dimension, and integer removes a dimension. As these indexing
// operations are applied left to right, the actual index that it's being
// applied to depends on the previous operations. Ellipses indexing throws
// another wrinkle. Ellipses selects any remaining unspecified dimensions.
// Thus, for indexes following an ellipses, the actual index an indexing
// operation is being applied to depends on the operations to the right.
// Thus, we do two passes, one from left to right up until the ellipses, and
// one from right to left.
std::vector<Value*> tensor_indices;
auto insert_value_for_dim = [&](int64_t dim) {
return graph->insertConstant(dim, nullptr, loc);
};
std::vector<int64_t> dims(subscript_exprs.size());
std::vector<c10::optional<Value*>> exprs(
subscript_exprs.size(), c10::nullopt);
auto handle_indexing = [&](const Expr& subscript_expr,
int expr_idx,
int64_t dim,
bool is_reverse = false) {
dims[expr_idx] = dim;
if (subscript_expr.kind() == TK_SLICE_EXPR) {
if (is_reverse) {
return dim - 1;
} else {
return dim + 1;
}
}
TypePtr type_hint = OptionalType::ofTensor();
if (subscript_expr.kind() == TK_NONE) {
type_hint = NoneType::get();
}
auto index = emitExpr(subscript_expr, type_hint);
exprs[expr_idx] = index;
if (index->type()->isSubtypeOf(NoneType::get())) {
if (is_reverse) {
return dim;
} else {
return dim + 1;
}
} else if (index->type() == IntType::get()) {
if (is_reverse) {
return dim - 1;
} else {
return dim;
}
} else if (index->type()->isSubtypeOf(OptionalType::ofTensor())) {
if (is_reverse) {
throw ErrorReport(loc)
<< "Ellipses followed by tensor indexing is currently not supported";
} else {
return dim + 1;
}
} else {
throw ErrorReport(loc)
<< "Unsupported operation: indexing tensor with unsupported index type '"
<< index->type()->python_str()
<< "'. Only ints, slices, and tensors are supported";
}
};
size_t idx = 0;
int64_t dim = 0;
for (; idx < subscript_exprs.size(); idx++) {
auto subscript_expr = subscript_exprs[idx];
if (subscript_expr.kind() == TK_DOTS) {
break;
}
dim = handle_indexing(subscript_expr, idx, dim, /*is_reverse=*/false);
}
int64_t rdim = -1;
for (size_t rev_idx = subscript_exprs.size() - 1; rev_idx > idx;
rev_idx--) {
auto subscript_expr = subscript_exprs[rev_idx];
if (subscript_expr.kind() == TK_DOTS) {
throw ErrorReport(loc)
<< "An index can only have a single ellipsis ('...')";
}
rdim =
handle_indexing(subscript_expr, rev_idx, rdim, /*is_reverse=*/true);
}
for (size_t i = 0; i < exprs.size(); i++) {
if (!exprs[i].has_value()) {
if (subscript_exprs[i].kind() == TK_SLICE_EXPR) {
sliceable = emitSlice(
loc,
sliceable,
insert_value_for_dim(dims[i]),
SliceExpr(subscript_exprs[i]));
}
continue;
}
auto expr = exprs[i].value();
if (expr->type()->isSubtypeOf(NoneType::get())) {
sliceable =
emitUnsqueeze(loc, sliceable, insert_value_for_dim(dims[i]));
} else if (expr->type() == IntType::get()) {
sliceable =
emitSelect(loc, sliceable, insert_value_for_dim(dims[i]), expr);
} else if (expr->type()->isSubtypeOf(OptionalType::ofTensor())) {
tensor_indices.resize(dims[i] + 1);
tensor_indices[dims[i]] = expr;
} else {
TORCH_INTERNAL_ASSERT(
"Trying to process index type that we don't support.");
}
}
// at::index takes in a List[Optional[Tensor]] where some dims can be None.
// create None node with optional tensor output type and pass to at::index.
for (auto& index : tensor_indices) {
if (index == nullptr) {
index =
graph->insertNode(graph->createNone(TensorType::get()))->output();
}
}
return std::make_pair(sliceable, tensor_indices);
}
// Desugars multidim slicing into slice/select/index/unsqueeze calls.
//
// XXX: Errors in user code are not elegantly reported.
// Let's say someone were to do the following:
// @torch.jit.script
// def fn(x):
// return x[0, 1]
// fn(torch.randn(5))
// Because we desugar this into two aten::select ops, the error message
// complains about aten::select failing rather than there "not being
// enough dimensions to index".
//
// The strategy is to slice and select the tensor for int and slices first
// in one pass and then apply at::index on the result of the
// slicing/selecting. Call the tensor after we've applied slice / select the
// `sliced`. tensor_indices should have the same size as sliced.dim():
// - tensor_indices[i] = NULL if we should not index `sliced` at dim i
// - tensor_indices[i] = t if we should index `sliced` at dim i with tensor t.
Value* emitMultidimSlicing(
const SourceRange& loc,
Value* sliceable,
const List<Expr>& subscript_exprs) {
if (!sliceable->type()->isSubtypeOf(TensorType::get())) {
throw ErrorReport(loc)
<< "Unsupported operation: attempted to use multidimensional "
<< "indexing on a non-tensor type";
}
std::vector<Value*> tensor_indices;
std::tie(sliceable, tensor_indices) =
emitIntAndSliceIndexing(loc, sliceable, subscript_exprs);
if (tensor_indices.empty()) {
// XXX: Might need to at::alias this when we support mutability
return sliceable;
}
return emitIndex(loc, sliceable, tensor_indices);
}
// Desugars slice syntactic sugar tensor[begin:end] -> tensor.slice(begin,
// end).
Value* emitBasicSlice(
const SourceRange& loc,
Value* sliceable,
const List<Expr>& subscript_exprs) {
AT_ASSERT(subscript_exprs.size() == 1);
AT_ASSERT(subscript_exprs[0].kind() == TK_SLICE_EXPR);
auto slice_exp = SliceExpr(subscript_exprs[0]);
Value* maybe_dim = nullptr;
if (sliceable->type()->isSubtypeOf(TensorType::get())) {
// If the sliceable object is a tensor, specify a default dimension
maybe_dim = graph->insertConstant(0, nullptr, loc);
}
return emitSlice(loc, sliceable, maybe_dim, slice_exp);
}
int64_t getAdjTupleIndex(
const SourceRange& loc,
const TupleTypePtr& tuple_type,
int64_t input_index,
bool allow_out_of_bounds) {
// set index to be positive to simplify logic in runtime
int64_t adj_index = input_index;
int64_t tuple_len = tuple_type->elements().size();
if (input_index < 0) {
adj_index = tuple_len + input_index;
}
if (!allow_out_of_bounds && (adj_index >= tuple_len || adj_index < 0)) {
throw ErrorReport(loc) << "Tuple index out of range. Tuple is length "
<< tuple_len << " and index is " << input_index;
}
return adj_index;
}
// When a list is marked const in a module, it gets converted to a tuple.
// The result is indexing into a Tuple which contains only one type
// is quite common. since indexing will likely be done in a for loop,
// we do not want to invoke the overhead of converting the tuple to a list
// each iter.
Value* emitTupleIndex(
const SourceRange& loc,
Value* tuple_val,
Value* idx_val) {
auto tuple_typ = tuple_val->type()->cast<TupleType>();
auto elems = tuple_typ->elements();
TypePtr output_type;
if (idx_val->type() != IntType::get()) {
throw ErrorReport(loc) << "tuple index must be an integer";
}
auto idx = toIValue(idx_val);
if (!idx) {
if (elems.size() == 0 ||
!convertibleToList(tuple_typ, ListType::create(elems[0]))) {
throw ErrorReport(loc)
<< "Cannot index into a " << tuple_typ->python_str()
<< " with a non-integer literal because we cannot resolve the output type";
}
output_type = elems[0];
} else {
auto adj_index = getAdjTupleIndex(
loc, tuple_typ, idx->toInt(), /*allow_out_of_bounds*/ false);
output_type = elems[adj_index];
}
return graph
->insertNode(graph->createTupleIndex(tuple_val, idx_val, output_type))
->output();
}
int64_t getSliceInd(Value* idx_val, const SourceRange& loc) {
auto ivalue = toIValue(idx_val);
if (ivalue && ivalue->isInt()) {
return ivalue->to<int64_t>();
} else {
throw ErrorReport(loc) << "tuple slice indices must be integer constants";
}
}
Value* emitTupleSlice(
const SourceRange& loc,
const NamedValue& tuple_val,
const NamedValue& beg_val,
const at::optional<NamedValue>& end_val) {
auto tuple_type = tuple_val.value(*graph)->type()->expect<TupleType>();
int64_t beg = getAdjTupleIndex(
loc,
tuple_type,
getSliceInd(beg_val.value(*graph), loc),
/*allow_out_of_bounds*/ true);
int64_t end;
int64_t tuple_len = tuple_type->elements().size();
if (end_val) {
end = getAdjTupleIndex(
loc, tuple_type, getSliceInd(end_val->value(*graph), loc), true);
} else {
end = tuple_len;
}
// slicing does not throw out of bounds errors
end = std::min(std::max((int64_t)0, end), tuple_len);
beg = std::min(std::max((int64_t)0, beg), tuple_len);
return graph
->insertNode(graph->createTupleSlice(tuple_val.value(*graph), beg, end))
->output();
}
Value* emitSubscript(const Subscript& subscript) {
const SugaredValuePtr sv = emitSugaredExpr(subscript.value(), 1);
const List<Expr>& subscript_exprs = subscript.subscript_exprs();
const SourceRange& range = subscript.range();
const SourceRange& val_range = subscript.value().range();
if (subscript_exprs.size() != 1) {
return emitMultidimSlicing(
range, sv->asValue(val_range, method), subscript_exprs);
}
if (subscript_exprs[0].kind() == TK_SLICE_EXPR) {
return emitBasicSlice(
range, sv->asValue(val_range, method), subscript_exprs);
} else {
// Desugars gather syntactic sugar foo[i]
Value* idx = emitExpr(subscript_exprs[0]);
Value* val = sv->asValue(val_range, method);
AT_ASSERT(subscript_exprs.size() == 1);
if (val->type()->cast<TupleType>()) {
return emitTupleIndex(range, sv->asValue(val_range, method), idx);
} else if (val->type()->isSubtypeOf(TensorType::get())) {
return emitMultidimSlicing(range, val, subscript_exprs);
} else {
return sv->getitem(range, method, idx);
}
}
}
};
struct FunctionResolver : public Resolver {
explicit FunctionResolver(
const Resolver* otherResolver,
const std::unordered_map<std::string, Function*>& functionTable)
: otherResolver_(otherResolver), functionTable_(functionTable) {}
std::shared_ptr<SugaredValue> resolveValue(
const std::string& name,
Function& m,
const SourceRange& loc) const override {
auto it = functionTable_.find(name);
if (it != functionTable_.end()) {
return std::make_shared<FunctionValue>(it->second);
}
return otherResolver_->resolveValue(name, m, loc);
}
TypePtr resolveType(const std::string& name, const SourceRange& loc)
const override {
return otherResolver_->resolveType(name, loc);
}
private:
const Resolver* otherResolver_;
const std::unordered_map<std::string, Function*>& functionTable_;
};
CompilationUnit::CompilationUnit(const std::string& source)
: CompilationUnit() {
// calles the define with native resolver to generate the graph for functions
define(c10::nullopt, source, nativeResolver(), nullptr);
}
// Mangle a qualified name so that it is globally unique.
std::string CompilationUnit::mangle(const std::string& name) const {
static const std::string manglePrefix = "___torch_mangle_";
std::string mangledName;
auto pos = name.find(manglePrefix);
if (pos != std::string::npos) {
// If the name is already mangled, avoid re-appending the prefix.
mangledName.reserve(name.size());
// Append the part of the name up to the end of the prefix
mangledName.append(name, 0, pos);
mangledName.append(std::to_string(mangleIndex_++));
} else {
mangledName = c10::str(name, manglePrefix, std::to_string(mangleIndex_++));
}
return mangledName;
}
std::unique_ptr<Function> CompilationUnit::define(
const c10::optional<QualifiedName>& prefix,
const Def& def,
const ResolverPtr& resolver,
const Self* self,
const std::unordered_map<std::string, Function*>& function_table,
bool shouldMangle) const {
TORCH_INTERNAL_ASSERT(resolver);
auto _resolver = resolver;
if (!self) {
// if self is defined, then these are methods and do not go into the
// global namespace otherwise, they get defined together so we add them to
// the function table so the methods can see each other
_resolver =
std::make_shared<FunctionResolver>(resolver.get(), function_table);
}
auto creator = [def, _resolver, self](Function& method) {
// Store the function name so that it can be referenced if there is an error
// while compiling this function
if (self) {
// Include the fully qualified name if this is a method
ErrorReport::CallStack::push_function(method.qualname().qualifiedName());
} else {
ErrorReport::CallStack::push_function(method.qualname().name());
}
to_ir(def, _resolver, self, method);
// Compilation was successful, so remove the function def info
ErrorReport::CallStack::pop_function();
};
auto name = prefix ? QualifiedName(*prefix, def.name().name())
: QualifiedName(def.name().name());
if (shouldMangle) {
// If `shouldMangle` is set, we should generate a unique name for this
// function if there is already an existing one.
if (auto fn = find_function(name)) {
auto newBase = mangle(name.name());
name = QualifiedName(name.prefix(), newBase);
}
}
auto fn = torch::make_unique<Function>(
std::move(name), std::make_shared<Graph>(), creator);
if (self) {
// Register this as a method on `self`'s type
self->getClassType()->addMethod(fn.get());
}
return fn;
}
std::vector<Function*> CompilationUnit::define(
const c10::optional<QualifiedName>& prefix,
const std::vector<Def>& definitions,
const std::vector<ResolverPtr>& resolvers,
const Self* self,
bool shouldMangle) {
TORCH_INTERNAL_ASSERT(definitions.size() == resolvers.size());
// We need to compile `__init__` first, since it can determine what attributes
// are available to other methods. So reorder the definitions accordingly.
c10::optional<size_t> init_idx;
for (size_t i = 0; i < definitions.size(); i++) {
const auto& def = definitions[i];
if (def.name().name() == "__init__") {
init_idx = i;
break;
}
}
std::vector<Function*> functions;
std::unordered_map<std::string, Function*> function_table;
if (init_idx.has_value()) {
// if we have an init, do it first.
auto fn = define(
prefix,
definitions[*init_idx],
resolvers[*init_idx],
self,
function_table,
shouldMangle);
const auto& name = fn->name();
function_table[name] = fn.get();
functions.push_back(fn.get());
register_function(std::move(fn));
}
for (size_t i = 0; i < definitions.size(); i++) {
if (init_idx.has_value() && i == *init_idx) {
// skip this def since it's already been compiled
continue;
}
auto fn = define(
prefix,
definitions[i],
resolvers[i],
self,
function_table,
shouldMangle);
const auto& name = fn->name();
function_table[name] = fn.get();
functions.push_back(fn.get());
register_function(std::move(fn));
}
for (Function* function : functions) {
function->ensure_defined();
}
return functions;
}
std::vector<Function*> CompilationUnit::define(
const c10::optional<QualifiedName>& prefix,
const std::string& source,
const ResolverPtr& resolver,
const Self* self) {
Parser p(std::make_shared<Source>(source, "<string>", 1));
std::vector<Def> definitions;
std::vector<ResolverPtr> resolvers;
while (p.lexer().cur().kind != TK_EOF) {
auto def = Def(p.parseFunction(/*is_method=*/bool(self)));
definitions.push_back(def);
resolvers.push_back(resolver);
}
return define(prefix, definitions, resolvers, self);
}
void runCleanupPasses(std::shared_ptr<Graph>& to_clean, bool convert_ssa) {
// the graph including closures is converted to ssa in the first pass,
// so subsequent cleanups do not need reconvert it
if (convert_ssa) {
ConvertToSSA(to_clean);
// convert loops with an iter and body condition specified to
// python-recognize while loops. we do this so they can be exported,
// and run the pass early to avoid jitter. Like conversion to SSA,
// it only needs to run once.
CanonicalizeModifiedLoops(to_clean);
}
// NB ORDERING: SSA conversion has to occur before
// lifting of closures and forks, this way closures are converted
// to SSA while part of their original graph, and closures are ready to
// be inlined into forked closures
liftClosures(to_clean);
inlineForkedClosures(to_clean);
if (script::getInlineEverythingMode()) {
Inline(*to_clean);
}
// remove any uses of tuples that we inserted that are not needed
LowerSimpleTuples(to_clean);
ConstantPooling(to_clean);
// For jitter
CanonicalizeOutputs(to_clean);
}
// we consider _N where N is a number, to be a non-meaningful name
// and do not record it as a unique name. This allows python printing to
// be able to export and import more consistently named graphs
bool meaningfulName(const std::string& name) {
if (name.size() == 0)
return false;
if (name[0] == '$')
return false;
if (name[0] != '_')
return true;
for (size_t i = 1; i < name.size(); ++i) {
if (!isdigit(name[i]))
return true;
}
return false;
}
void lambdaLiftFork(Node* fork_node) {
// Fork a new graph from its orignal owning graph
auto forked_graph = std::make_shared<Graph>();
auto body_block = fork_node->blocks()[0];
// Make sure we capture everything in the new graph.
// The uncaptured values will be added to the fork signature.
std::unordered_map<Value*, Value*> uncaptures_map;
auto env = [&](Value* v) -> Value* {
if (!uncaptures_map.count(v)) {
// Capture values for both graphs
uncaptures_map[v] = forked_graph->addInput()->copyMetadata(v);
fork_node->addInput(v);
}
return uncaptures_map[v];
};
forked_graph->block()->cloneFrom(body_block, env);
// Separate the subgraph and clean up the orignal one
fork_node->g_(attr::Subgraph, forked_graph);
fork_node->eraseBlock(0);
}
} // namespace script
} // namespace jit
} // namespace torch