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// Copyright 2013 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/common/globals.h"
#include "src/compiler/node.h"
#include "src/compiler/operator-properties.h"
#include "src/compiler/types.h"
#include "src/objects/map.h"
#include "src/zone/zone-handle-set.h"
namespace v8 {
namespace internal {
namespace compiler {
class Graph;
class Operator;
class CommonOperatorBuilder;
// A facade that simplifies access to the different kinds of inputs to a node.
class V8_EXPORT_PRIVATE NodeProperties final {
// ---------------------------------------------------------------------------
// Input layout.
// Inputs are always arranged in order as follows:
// 0 [ values, context, frame state, effects, control ] node->InputCount()
static int FirstValueIndex(Node* node) { return 0; }
static int FirstContextIndex(Node* node) { return PastValueIndex(node); }
static int FirstFrameStateIndex(Node* node) { return PastContextIndex(node); }
static int FirstEffectIndex(Node* node) { return PastFrameStateIndex(node); }
static int FirstControlIndex(Node* node) { return PastEffectIndex(node); }
static int PastValueIndex(Node* node) {
return FirstValueIndex(node) + node->op()->ValueInputCount();
static int PastContextIndex(Node* node) {
return FirstContextIndex(node) +
static int PastFrameStateIndex(Node* node) {
return FirstFrameStateIndex(node) +
static int PastEffectIndex(Node* node) {
return FirstEffectIndex(node) + node->op()->EffectInputCount();
static int PastControlIndex(Node* node) {
return FirstControlIndex(node) + node->op()->ControlInputCount();
// ---------------------------------------------------------------------------
// Input accessors.
static Node* GetValueInput(Node* node, int index) {
CHECK_LE(0, index);
CHECK_LT(index, node->op()->ValueInputCount());
return node->InputAt(FirstValueIndex(node) + index);
static Node* GetContextInput(Node* node) {
return node->InputAt(FirstContextIndex(node));
static Node* GetFrameStateInput(Node* node) {
return node->InputAt(FirstFrameStateIndex(node));
static Node* GetEffectInput(Node* node, int index = 0) {
CHECK_LE(0, index);
CHECK_LT(index, node->op()->EffectInputCount());
return node->InputAt(FirstEffectIndex(node) + index);
static Node* GetControlInput(Node* node, int index = 0) {
CHECK_LE(0, index);
CHECK_LT(index, node->op()->ControlInputCount());
return node->InputAt(FirstControlIndex(node) + index);
// ---------------------------------------------------------------------------
// Edge kinds.
static bool IsValueEdge(Edge edge);
static bool IsContextEdge(Edge edge);
static bool IsFrameStateEdge(Edge edge);
static bool IsEffectEdge(Edge edge);
static bool IsControlEdge(Edge edge);
// ---------------------------------------------------------------------------
// Miscellaneous predicates.
static bool IsCommon(Node* node) {
return IrOpcode::IsCommonOpcode(node->opcode());
static bool IsControl(Node* node) {
return IrOpcode::IsControlOpcode(node->opcode());
static bool IsConstant(Node* node) {
return IrOpcode::IsConstantOpcode(node->opcode());
static bool IsPhi(Node* node) {
return IrOpcode::IsPhiOpcode(node->opcode());
// Determines whether exceptions thrown by the given node are handled locally
// within the graph (i.e. an IfException projection is present). Optionally
// the present IfException projection is returned via {out_exception}.
static bool IsExceptionalCall(Node* node, Node** out_exception = nullptr);
// Returns the node producing the successful control output of {node}. This is
// the IfSuccess projection of {node} if present and {node} itself otherwise.
static Node* FindSuccessfulControlProjection(Node* node);
// Returns whether the node acts as the identity function on a value
// input. The input that is passed through is returned via {out_value}.
static bool IsValueIdentity(Node* node, Node** out_value) {
switch (node->opcode()) {
case IrOpcode::kTypeGuard:
*out_value = GetValueInput(node, 0);
return true;
case IrOpcode::kFoldConstant:
*out_value = GetValueInput(node, 1);
return true;
return false;
// ---------------------------------------------------------------------------
// Miscellaneous mutators.
static void ReplaceValueInput(Node* node, Node* value, int index);
static void ReplaceContextInput(Node* node, Node* context);
static void ReplaceControlInput(Node* node, Node* control, int index = 0);
static void ReplaceEffectInput(Node* node, Node* effect, int index = 0);
static void ReplaceFrameStateInput(Node* node, Node* frame_state);
static void RemoveNonValueInputs(Node* node);
static void RemoveValueInputs(Node* node);
// Replaces all value inputs of {node} with the single input {value}.
static void ReplaceValueInputs(Node* node, Node* value);
// Merge the control node {node} into the end of the graph, introducing a
// merge node or expanding an existing merge node if necessary.
static void MergeControlToEnd(Graph* graph, CommonOperatorBuilder* common,
Node* node);
// Removes the control node {node} from the end of the graph, reducing the
// existing merge node's input count.
static void RemoveControlFromEnd(Graph* graph, CommonOperatorBuilder* common,
Node* node);
// Replace all uses of {node} with the given replacement nodes. All occurring
// use kinds need to be replaced, {nullptr} is only valid if a use kind is
// guaranteed not to exist.
static void ReplaceUses(Node* node, Node* value, Node* effect = nullptr,
Node* success = nullptr, Node* exception = nullptr);
// Safe wrapper to mutate the operator of a node. Checks that the node is
// currently in a state that satisfies constraints of the new operator.
static void ChangeOp(Node* node, const Operator* new_op);
// ---------------------------------------------------------------------------
// Miscellaneous utilities.
// Find the last frame state that is effect-wise before the given node. This
// assumes a linear effect-chain up to a {CheckPoint} node in the graph.
// Returns {unreachable_sentinel} if {node} is determined to be unreachable.
static Node* FindFrameStateBefore(Node* node, Node* unreachable_sentinel);
// Collect the output-value projection for the given output index.
static Node* FindProjection(Node* node, size_t projection_index);
// Collect the value projections from a node.
static void CollectValueProjections(Node* node, Node** proj, size_t count);
// Collect the branch-related projections from a node, such as IfTrue,
// IfFalse, IfSuccess, IfException, IfValue and IfDefault.
// - Branch: [ IfTrue, IfFalse ]
// - Call : [ IfSuccess, IfException ]
// - Switch: [ IfValue, ..., IfDefault ]
static void CollectControlProjections(Node* node, Node** proj, size_t count);
// Checks if two nodes are the same, looking past {CheckHeapObject}.
static bool IsSame(Node* a, Node* b);
// Check if two nodes have equal operators and reference-equal inputs. Used
// for value numbering/hash-consing.
static bool Equals(Node* a, Node* b);
// A corresponding hash function.
static size_t HashCode(Node* node);
// Walks up the {effect} chain to find a witness that provides map
// information about the {receiver}. Can look through potentially
// side effecting nodes.
enum InferMapsResult {
kNoMaps, // No maps inferred.
kReliableMaps, // Maps can be trusted.
kUnreliableMaps // Maps might have changed (side-effect).
// DO NOT USE InferMapsUnsafe IN NEW CODE. Use MapInference instead.
static InferMapsResult InferMapsUnsafe(JSHeapBroker* broker, Node* object,
Node* effect,
ZoneHandleSet<Map>* maps);
// Return the initial map of the new-target if the allocation can be inlined.
static base::Optional<MapRef> GetJSCreateMap(JSHeapBroker* broker,
Node* receiver);
// Walks up the {effect} chain to check that there's no observable side-effect
// between the {effect} and it's {dominator}. Aborts the walk if there's join
// in the effect chain.
static bool NoObservableSideEffectBetween(Node* effect, Node* dominator);
// Returns true if the {receiver} can be a primitive value (i.e. is not
// definitely a JavaScript object); might walk up the {effect} chain to
// find map checks on {receiver}.
static bool CanBePrimitive(JSHeapBroker* broker, Node* receiver,
Node* effect);
// Returns true if the {receiver} can be null or undefined. Might walk
// up the {effect} chain to find map checks for {receiver}.
static bool CanBeNullOrUndefined(JSHeapBroker* broker, Node* receiver,
Node* effect);
// ---------------------------------------------------------------------------
// Context.
// Walk up the context chain from the given {node} until we reduce the {depth}
// to 0 or hit a node that does not extend the context chain ({depth} will be
// updated accordingly).
static Node* GetOuterContext(Node* node, size_t* depth);
// ---------------------------------------------------------------------------
// Type.
static bool IsTyped(Node* node) { return !node->type().IsInvalid(); }
static Type GetType(Node* node) {
return node->type();
static Type GetTypeOrAny(Node* node);
static void SetType(Node* node, Type type) {
static void RemoveType(Node* node) { node->set_type(Type::Invalid()); }
static bool AllValueInputsAreTyped(Node* node);
static inline bool IsInputRange(Edge edge, int first, int count);
} // namespace compiler
} // namespace internal
} // namespace v8