dart::UnboxIntegerInstr Class Reference

#include <il.h>

Inheritance diagram for dart::UnboxIntegerInstr:

Public Types
enum	TruncationMode { kTruncate , kNoTruncation }
Public Types inherited from dart::TemplateDefinition< 1, NoThrow, Pure >
using	BaseClass = typename Pure< Definition, PureDefinition >::Base

Public Member Functions
	UnboxIntegerInstr (Representation representation, TruncationMode truncation_mode, Value *value, intptr_t deopt_id, SpeculativeMode speculative_mode)
bool	is_truncating () const
void	mark_truncating ()
virtual bool	ComputeCanDeoptimize () const
virtual bool	AttributesEqual (const Instruction &other) const
virtual Definition *	Canonicalize (FlowGraph *flow_graph)
virtual void	InferRange (RangeAnalysis *analysis, Range *range)
Public Member Functions inherited from dart::UnboxInstr
Value *	value () const
virtual SpeculativeMode	SpeculativeModeOfInput (intptr_t index) const
virtual Representation	representation () const
Definition *	Canonicalize (FlowGraph *flow_graph)
virtual intptr_t	DeoptimizationTarget () const
virtual TokenPosition	token_pos () const
	DECLARE_INSTRUCTION_SERIALIZABLE_FIELDS (UnboxInstr, TemplateDefinition, FIELD_LIST) protected
void	set_speculative_mode (SpeculativeMode value)
Public Member Functions inherited from dart::TemplateDefinition< 1, NoThrow, Pure >
	TemplateDefinition (intptr_t deopt_id=DeoptId::kNone)
	TemplateDefinition (const InstructionSource &source, intptr_t deopt_id=DeoptId::kNone)
virtual intptr_t	InputCount () const
virtual Value *	InputAt (intptr_t i) const
virtual bool	MayThrow () const

Additional Inherited Members
Static Public Member Functions inherited from dart::UnboxInstr
static UnboxInstr *	Create (Representation to, Value *value, intptr_t deopt_id, SpeculativeMode speculative_mode=kGuardInputs)
Protected Attributes inherited from dart::TemplateDefinition< 1, NoThrow, Pure >
EmbeddedArray< Value *, N >	inputs_

Detailed Description

Definition at line 8712 of file il.h.

Member Enumeration Documentation

TruncationMode

enum dart::UnboxIntegerInstr::TruncationMode

Enumerator
kTruncate
kNoTruncation

Definition at line 8714 of file il.h.

{ kTruncate, kNoTruncation };

Constructor & Destructor Documentation

UnboxIntegerInstr()

dart::UnboxIntegerInstr::UnboxIntegerInstr ( Representation  representation, TruncationMode  truncation_mode, Value *  value, intptr_t  deopt_id, SpeculativeMode  speculative_mode  )

inline

Definition at line 8716 of file il.h.

      : UnboxInstr(representation, value, deopt_id, speculative_mode),
        is_truncating_(truncation_mode == kTruncate) {}

Member Function Documentation

AttributesEqual()

virtual bool dart::UnboxIntegerInstr::AttributesEqual ( const Instruction &  other ) const

inlinevirtual

Reimplemented from dart::UnboxInstr.

Definition at line 8730 of file il.h.

                                                               {
    auto const other_unbox = other.AsUnboxInteger();
    return UnboxInstr::AttributesEqual(other) &&
           (other_unbox->is_truncating_ == is_truncating_);
  }

Canonicalize()

Definition * dart::UnboxIntegerInstr::Canonicalize ( FlowGraph *  flow_graph )

virtual

Definition at line 3367 of file il.cc.

                                                                 {
  if (!HasUses() && !CanDeoptimize()) return nullptr;
 
  // Fold away Unbox<rep>(v) if v has a target representation already.
  Definition* value_defn = value()->definition();
  if (value_defn->representation() == representation()) {
    return value_defn;
  }
 
  // Do not attempt to fold this instruction if we have not matched
  // input/output representations yet.
  if (HasUnmatchedInputRepresentations()) {
    return this;
  }
 
  // Fold away UnboxInteger<rep_to>(BoxInteger<rep_from>(v)).
  BoxIntegerInstr* box_defn = value()->definition()->AsBoxInteger();
  if (box_defn != nullptr && !box_defn->HasUnmatchedInputRepresentations()) {
    Representation from_representation =
        box_defn->value()->definition()->representation();
    if (from_representation == representation()) {
      return box_defn->value()->definition();
    } else {
      // Only operate on explicit unboxed operands.
      IntConverterInstr* converter = new IntConverterInstr(
          from_representation, representation(),
          box_defn->value()->CopyWithType(),
          (representation() == kUnboxedInt32) ? GetDeoptId() : DeoptId::kNone);
      // TODO(vegorov): marking resulting converter as truncating when
      // unboxing can't deoptimize is a workaround for the missing
      // deoptimization environment when we insert converter after
      // EliminateEnvironments and there is a mismatch between predicates
      // UnboxIntConverterInstr::CanDeoptimize and UnboxInt32::CanDeoptimize.
      if ((representation() == kUnboxedInt32) &&
          (is_truncating() || !CanDeoptimize())) {
        converter->mark_truncating();
      }
      flow_graph->InsertBefore(this, converter, env(), FlowGraph::kValue);
      return converter;
    }
  }
 
  if ((SpeculativeModeOfInput(0) == kGuardInputs) && !ComputeCanDeoptimize()) {
    // Remember if we ever learn out input doesn't require checking, as
    // the input Value might be later changed that would make us forget.
    set_speculative_mode(kNotSpeculative);
  }
 
  if (value()->BindsToConstant()) {
    const auto& obj = value()->BoundConstant();
    if (obj.IsInteger()) {
      if (representation() == kUnboxedInt64) {
        return flow_graph->GetConstant(obj, representation());
      }
      const int64_t intval = Integer::Cast(obj).AsInt64Value();
      if (RepresentationUtils::IsRepresentable(representation(), intval)) {
        return flow_graph->GetConstant(obj, representation());
      }
      if (is_truncating()) {
        const int64_t result = Evaluator::TruncateTo(intval, representation());
        return flow_graph->GetConstant(
            Integer::ZoneHandle(flow_graph->zone(),
                                Integer::NewCanonical(result)),
            representation());
      }
    }
  }
 
  return this;
}

ComputeCanDeoptimize()

bool dart::UnboxIntegerInstr::ComputeCanDeoptimize ( ) const

virtual

Reimplemented from dart::UnboxInstr.

Definition at line 2031 of file il.cc.

                                                   {
  if (SpeculativeModeOfInputs() == kNotSpeculative) {
    return false;
  }
  if (!value()->Type()->IsInt()) {
    return true;
  }
  if (representation() == kUnboxedInt64 || is_truncating()) {
    return false;
  }
  const intptr_t rep_bitsize =
      RepresentationUtils::ValueSize(representation()) * kBitsPerByte;
  if (value()->Type()->ToCid() == kSmiCid &&
      compiler::target::kSmiBits <= rep_bitsize) {
    return false;
  }
  return !RangeUtils::IsWithin(value()->definition()->range(),
                               RepresentationUtils::MinValue(representation()),
                               RepresentationUtils::MaxValue(representation()));
}

InferRange()

void dart::UnboxIntegerInstr::InferRange ( RangeAnalysis *  analysis, Range *  range  )

virtual

Definition at line 3075 of file range_analysis.cc.

                                                                        {
  auto* const value_range = value()->Type()->ToCid() == kSmiCid
                                ? analysis->GetSmiRange(value())
                                : value()->definition()->range();
  const Range to_range = Range::Full(representation());
 
  if (Range::IsUnknown(value_range)) {
    *range = to_range;
  } else if (value_range->IsWithin(&to_range)) {
    *range = *value_range;
  } else if (is_truncating()) {
    // If truncating, then in most cases any non-representable values means
    // no assumption can be made about the truncated value.
    *range = to_range;
  } else {
    // When not truncating, then unboxing deoptimizes if the value is outside
    // the range representation.
    *range = value_range->Intersect(&to_range);
  }
  ASSERT_VALID_RANGE_FOR_REPRESENTATION(this, range, representation());
}

is_truncating()

bool dart::UnboxIntegerInstr::is_truncating ( ) const

inline

Definition at line 8724 of file il.h.

{ return is_truncating_; }

mark_truncating()

void dart::UnboxIntegerInstr::mark_truncating ( )

inline

Definition at line 8726 of file il.h.

{ is_truncating_ = true; }

---

The documentation for this class was generated from the following files:

• third_party/dart-lang/sdk/runtime/vm/compiler/backend/il.h
• third_party/dart-lang/sdk/runtime/vm/compiler/backend/il.cc
• third_party/dart-lang/sdk/runtime/vm/compiler/backend/range_analysis.cc