Aart Bik
fa6fce61fa
Rationale: Previous method cached graph information (instruction and call site counts) on a per-function level, not accounting for potential specializations. The improved method runs an extra constant folding pass, and only caches per-function information for non-specialized cases. As a result, we inling much better, see for example, the added test as illustration. Since we no longer cache for constants, compile-time may be increased a bit due to the extra scan. In the long run we should consider for common constant "situations" as the call site. https://github.com/dart-lang/sdk/issues/36880 Change-Id: I19f007c7f1860ad0ea88fafb38695dc154189ad5 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/105460 Commit-Queue: Aart Bik <ajcbik@google.com> Reviewed-by: Martin Kustermann <kustermann@google.com> Reviewed-by: Alexander Markov <alexmarkov@google.com>
1615 lines
56 KiB
C++
1615 lines
56 KiB
C++
// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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#if !defined(DART_PRECOMPILED_RUNTIME)
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#include "vm/compiler/backend/constant_propagator.h"
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#include "vm/bit_vector.h"
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#include "vm/compiler/backend/flow_graph_compiler.h"
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#include "vm/compiler/backend/il.h"
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#include "vm/compiler/backend/il_printer.h"
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#include "vm/compiler/backend/range_analysis.h"
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#include "vm/compiler/frontend/flow_graph_builder.h"
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#include "vm/parser.h"
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#include "vm/symbols.h"
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namespace dart {
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DEFINE_FLAG(bool, remove_redundant_phis, true, "Remove redundant phis.");
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DEFINE_FLAG(bool,
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trace_constant_propagation,
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false,
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"Print constant propagation and useless code elimination.");
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// Quick access to the current zone and isolate.
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#define I (isolate())
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#define Z (graph_->zone())
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#define T (graph_->thread())
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ConstantPropagator::ConstantPropagator(
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FlowGraph* graph,
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const GrowableArray<BlockEntryInstr*>& ignored)
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: FlowGraphVisitor(ignored),
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graph_(graph),
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unknown_(Object::unknown_constant()),
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non_constant_(Object::non_constant()),
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reachable_(new (Z) BitVector(Z, graph->preorder().length())),
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marked_phis_(new (Z) BitVector(Z, graph->max_virtual_register_number())),
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block_worklist_(),
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definition_worklist_(graph, 10) {}
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void ConstantPropagator::Optimize(FlowGraph* graph) {
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GrowableArray<BlockEntryInstr*> ignored;
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ConstantPropagator cp(graph, ignored);
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cp.Analyze();
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cp.Transform();
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}
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void ConstantPropagator::OptimizeBranches(FlowGraph* graph) {
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GrowableArray<BlockEntryInstr*> ignored;
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ConstantPropagator cp(graph, ignored);
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cp.Analyze();
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cp.Transform();
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cp.EliminateRedundantBranches();
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}
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void ConstantPropagator::SetReachable(BlockEntryInstr* block) {
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if (!reachable_->Contains(block->preorder_number())) {
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reachable_->Add(block->preorder_number());
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block_worklist_.Add(block);
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}
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}
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bool ConstantPropagator::SetValue(Definition* definition, const Object& value) {
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// We would like to assert we only go up (toward non-constant) in the lattice.
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//
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// ASSERT(IsUnknown(definition->constant_value()) ||
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// IsNonConstant(value) ||
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// (definition->constant_value().raw() == value.raw()));
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//
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// But the final disjunct is not true (e.g., mint or double constants are
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// heap-allocated and so not necessarily pointer-equal on each iteration).
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if (definition->constant_value().raw() != value.raw()) {
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definition->constant_value() = value.raw();
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if (definition->input_use_list() != NULL) {
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definition_worklist_.Add(definition);
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}
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return true;
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}
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return false;
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}
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static bool IsIdenticalConstants(const Object& left, const Object& right) {
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// This should be kept in line with Identical_comparison (identical.cc)
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// (=> Instance::IsIdenticalTo in object.cc).
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if (left.raw() == right.raw()) return true;
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if (left.GetClassId() != right.GetClassId()) return false;
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if (left.IsInteger()) {
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return Integer::Cast(left).Equals(Integer::Cast(right));
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}
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if (left.IsDouble()) {
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return Double::Cast(left).BitwiseEqualsToDouble(
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Double::Cast(right).value());
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}
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return false;
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}
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// Compute the join of two values in the lattice, assign it to the first.
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void ConstantPropagator::Join(Object* left, const Object& right) {
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// Join(non-constant, X) = non-constant
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// Join(X, unknown) = X
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if (IsNonConstant(*left) || IsUnknown(right)) return;
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// Join(unknown, X) = X
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// Join(X, non-constant) = non-constant
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if (IsUnknown(*left) || IsNonConstant(right)) {
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*left = right.raw();
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return;
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}
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// Join(X, X) = X
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if (IsIdenticalConstants(*left, right)) return;
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// Join(X, Y) = non-constant
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*left = non_constant_.raw();
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}
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// --------------------------------------------------------------------------
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// Analysis of blocks. Called at most once per block. The block is already
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// marked as reachable. All instructions in the block are analyzed.
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void ConstantPropagator::VisitGraphEntry(GraphEntryInstr* block) {
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for (auto def : *block->initial_definitions()) {
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def->Accept(this);
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}
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ASSERT(ForwardInstructionIterator(block).Done());
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// TODO(fschneider): Improve this approximation. The catch entry is only
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// reachable if a call in the try-block is reachable.
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for (intptr_t i = 0; i < block->SuccessorCount(); ++i) {
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SetReachable(block->SuccessorAt(i));
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}
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}
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void ConstantPropagator::VisitFunctionEntry(FunctionEntryInstr* block) {
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for (auto def : *block->initial_definitions()) {
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def->Accept(this);
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}
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for (ForwardInstructionIterator it(block); !it.Done(); it.Advance()) {
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it.Current()->Accept(this);
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}
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}
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void ConstantPropagator::VisitNativeEntry(NativeEntryInstr* block) {
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VisitFunctionEntry(block);
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}
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void ConstantPropagator::VisitOsrEntry(OsrEntryInstr* block) {
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for (auto def : *block->initial_definitions()) {
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def->Accept(this);
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}
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for (ForwardInstructionIterator it(block); !it.Done(); it.Advance()) {
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it.Current()->Accept(this);
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}
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}
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void ConstantPropagator::VisitCatchBlockEntry(CatchBlockEntryInstr* block) {
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for (auto def : *block->initial_definitions()) {
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def->Accept(this);
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}
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for (ForwardInstructionIterator it(block); !it.Done(); it.Advance()) {
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it.Current()->Accept(this);
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}
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}
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void ConstantPropagator::VisitJoinEntry(JoinEntryInstr* block) {
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// Phis are visited when visiting Goto at a predecessor. See VisitGoto.
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for (ForwardInstructionIterator it(block); !it.Done(); it.Advance()) {
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it.Current()->Accept(this);
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}
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}
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void ConstantPropagator::VisitTargetEntry(TargetEntryInstr* block) {
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for (ForwardInstructionIterator it(block); !it.Done(); it.Advance()) {
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it.Current()->Accept(this);
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}
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}
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void ConstantPropagator::VisitIndirectEntry(IndirectEntryInstr* block) {
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for (ForwardInstructionIterator it(block); !it.Done(); it.Advance()) {
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it.Current()->Accept(this);
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}
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}
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void ConstantPropagator::VisitParallelMove(ParallelMoveInstr* instr) {
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// Parallel moves have not yet been inserted in the graph.
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UNREACHABLE();
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}
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// --------------------------------------------------------------------------
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// Analysis of control instructions. Unconditional successors are
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// reachable. Conditional successors are reachable depending on the
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// constant value of the condition.
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void ConstantPropagator::VisitReturn(ReturnInstr* instr) {
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// Nothing to do.
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}
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void ConstantPropagator::VisitNativeReturn(NativeReturnInstr* instr) {
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// Nothing to do.
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}
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void ConstantPropagator::VisitThrow(ThrowInstr* instr) {
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// Nothing to do.
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}
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void ConstantPropagator::VisitReThrow(ReThrowInstr* instr) {
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// Nothing to do.
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}
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void ConstantPropagator::VisitStop(StopInstr* instr) {
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// Nothing to do.
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}
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void ConstantPropagator::VisitGoto(GotoInstr* instr) {
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SetReachable(instr->successor());
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// Phi value depends on the reachability of a predecessor. We have
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// to revisit phis every time a predecessor becomes reachable.
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for (PhiIterator it(instr->successor()); !it.Done(); it.Advance()) {
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it.Current()->Accept(this);
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}
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}
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void ConstantPropagator::VisitIndirectGoto(IndirectGotoInstr* instr) {
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for (intptr_t i = 0; i < instr->SuccessorCount(); i++) {
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SetReachable(instr->SuccessorAt(i));
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}
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}
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void ConstantPropagator::VisitBranch(BranchInstr* instr) {
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instr->comparison()->Accept(this);
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// The successors may be reachable, but only if this instruction is. (We
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// might be analyzing it because the constant value of one of its inputs
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// has changed.)
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if (reachable_->Contains(instr->GetBlock()->preorder_number())) {
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if (instr->constant_target() != NULL) {
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ASSERT((instr->constant_target() == instr->true_successor()) ||
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(instr->constant_target() == instr->false_successor()));
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SetReachable(instr->constant_target());
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} else {
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const Object& value = instr->comparison()->constant_value();
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if (IsNonConstant(value)) {
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SetReachable(instr->true_successor());
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SetReachable(instr->false_successor());
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} else if (value.raw() == Bool::True().raw()) {
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SetReachable(instr->true_successor());
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} else if (!IsUnknown(value)) { // Any other constant.
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SetReachable(instr->false_successor());
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}
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}
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}
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}
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// --------------------------------------------------------------------------
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// Analysis of non-definition instructions. They do not have values so they
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// cannot have constant values.
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void ConstantPropagator::VisitCheckStackOverflow(
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CheckStackOverflowInstr* instr) {}
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void ConstantPropagator::VisitCheckClass(CheckClassInstr* instr) {}
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void ConstantPropagator::VisitCheckCondition(CheckConditionInstr* instr) {}
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void ConstantPropagator::VisitCheckClassId(CheckClassIdInstr* instr) {}
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void ConstantPropagator::VisitGuardFieldClass(GuardFieldClassInstr* instr) {}
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void ConstantPropagator::VisitGuardFieldLength(GuardFieldLengthInstr* instr) {}
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void ConstantPropagator::VisitGuardFieldType(GuardFieldTypeInstr* instr) {}
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void ConstantPropagator::VisitCheckSmi(CheckSmiInstr* instr) {}
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void ConstantPropagator::VisitTailCall(TailCallInstr* instr) {}
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void ConstantPropagator::VisitCheckEitherNonSmi(CheckEitherNonSmiInstr* instr) {
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}
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void ConstantPropagator::VisitStoreUntagged(StoreUntaggedInstr* instr) {}
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void ConstantPropagator::VisitStoreIndexedUnsafe(
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StoreIndexedUnsafeInstr* instr) {}
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void ConstantPropagator::VisitStoreIndexed(StoreIndexedInstr* instr) {}
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void ConstantPropagator::VisitStoreInstanceField(
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StoreInstanceFieldInstr* instr) {}
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void ConstantPropagator::VisitDeoptimize(DeoptimizeInstr* instr) {
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// TODO(vegorov) remove all code after DeoptimizeInstr as dead.
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}
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Definition* ConstantPropagator::UnwrapPhi(Definition* defn) {
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if (defn->IsPhi()) {
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JoinEntryInstr* block = defn->AsPhi()->block();
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Definition* input = NULL;
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for (intptr_t i = 0; i < defn->InputCount(); ++i) {
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if (reachable_->Contains(block->PredecessorAt(i)->preorder_number())) {
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if (input == NULL) {
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input = defn->InputAt(i)->definition();
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} else {
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return defn;
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}
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}
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}
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return input;
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}
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return defn;
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}
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void ConstantPropagator::MarkPhi(Definition* phi) {
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ASSERT(phi->IsPhi());
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marked_phis_->Add(phi->ssa_temp_index());
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}
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// --------------------------------------------------------------------------
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// Analysis of definitions. Compute the constant value. If it has changed
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// and the definition has input uses, add the definition to the definition
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// worklist so that the used can be processed.
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void ConstantPropagator::VisitPhi(PhiInstr* instr) {
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// Compute the join over all the reachable predecessor values.
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JoinEntryInstr* block = instr->block();
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Object& value = Object::ZoneHandle(Z, Unknown());
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for (intptr_t pred_idx = 0; pred_idx < instr->InputCount(); ++pred_idx) {
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if (reachable_->Contains(
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block->PredecessorAt(pred_idx)->preorder_number())) {
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Join(&value, instr->InputAt(pred_idx)->definition()->constant_value());
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}
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}
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if (!SetValue(instr, value) &&
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marked_phis_->Contains(instr->ssa_temp_index())) {
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marked_phis_->Remove(instr->ssa_temp_index());
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definition_worklist_.Add(instr);
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}
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}
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void ConstantPropagator::VisitRedefinition(RedefinitionInstr* instr) {
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const Object& value = instr->value()->definition()->constant_value();
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if (IsConstant(value)) {
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SetValue(instr, value);
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} else {
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SetValue(instr, non_constant_);
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}
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}
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void ConstantPropagator::VisitCheckArrayBound(CheckArrayBoundInstr* instr) {
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// Don't propagate constants through check, since it would eliminate
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// the data dependence between the bound check and the load/store.
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// Graph finalization will expose the constant eventually.
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SetValue(instr, non_constant_);
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}
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void ConstantPropagator::VisitGenericCheckBound(GenericCheckBoundInstr* instr) {
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// Don't propagate constants through check, since it would eliminate
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// the data dependence between the bound check and the load/store.
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// Graph finalization will expose the constant eventually.
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SetValue(instr, non_constant_);
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}
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void ConstantPropagator::VisitCheckNull(CheckNullInstr* instr) {
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// Don't propagate constants through check, since it would eliminate
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// the data dependence between the null check and its use.
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// Graph finalization will expose the constant eventually.
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SetValue(instr, non_constant_);
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}
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void ConstantPropagator::VisitParameter(ParameterInstr* instr) {
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SetValue(instr, non_constant_);
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}
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void ConstantPropagator::VisitNativeParameter(NativeParameterInstr* instr) {
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SetValue(instr, non_constant_);
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}
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void ConstantPropagator::VisitPushArgument(PushArgumentInstr* instr) {
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if (SetValue(instr, instr->value()->definition()->constant_value())) {
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// The worklist implementation breaks down around push arguments,
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// since these instructions do not have a direct use-link to the
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// corresponding call. This is remedied by visiting all calls in
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// the enviroment use list each time a push argument changes its
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// value. Currently, this only needs to be done for static calls
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// (the only calls involved in constant propagation).
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// TODO(ajcbik): calls with multiple arguments may be revisited
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// several times; a direct use-link would be better
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for (Value* use = instr->env_use_list(); use != nullptr;
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use = use->next_use()) {
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if (use->instruction()->IsStaticCall()) {
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use->instruction()->Accept(this);
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}
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}
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}
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}
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void ConstantPropagator::VisitAssertAssignable(AssertAssignableInstr* instr) {
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const Object& value = instr->value()->definition()->constant_value();
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if (IsNonConstant(value)) {
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SetValue(instr, non_constant_);
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} else if (IsConstant(value)) {
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// We are ignoring the instantiator and instantiator_type_arguments, but
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// still monotonic and safe.
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if (instr->value()->Type()->IsAssignableTo(instr->dst_type())) {
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SetValue(instr, value);
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} else {
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SetValue(instr, non_constant_);
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}
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}
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}
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void ConstantPropagator::VisitAssertSubtype(AssertSubtypeInstr* instr) {}
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void ConstantPropagator::VisitAssertBoolean(AssertBooleanInstr* instr) {
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const Object& value = instr->value()->definition()->constant_value();
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if (IsNonConstant(value)) {
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SetValue(instr, non_constant_);
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} else if (IsConstant(value)) {
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if (value.IsBool()) {
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SetValue(instr, value);
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} else {
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SetValue(instr, non_constant_);
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}
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}
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}
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void ConstantPropagator::VisitSpecialParameter(SpecialParameterInstr* instr) {
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SetValue(instr, non_constant_);
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}
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void ConstantPropagator::VisitClosureCall(ClosureCallInstr* instr) {
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SetValue(instr, non_constant_);
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}
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void ConstantPropagator::VisitInstanceCall(InstanceCallInstr* instr) {
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SetValue(instr, non_constant_);
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}
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void ConstantPropagator::VisitPolymorphicInstanceCall(
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PolymorphicInstanceCallInstr* instr) {
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SetValue(instr, non_constant_);
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}
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void ConstantPropagator::VisitStaticCall(StaticCallInstr* instr) {
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const auto kind = MethodRecognizer::RecognizeKind(instr->function());
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switch (kind) {
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case MethodRecognizer::kOneByteString_equality:
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case MethodRecognizer::kTwoByteString_equality: {
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ASSERT(instr->FirstArgIndex() == 0);
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// Use pure identity as a fast equality test.
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if (instr->ArgumentAt(0)->OriginalDefinition() ==
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instr->ArgumentAt(1)->OriginalDefinition()) {
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SetValue(instr, Bool::True());
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return;
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}
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// Otherwise evaluate string compare with propagated constants.
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const Object& o1 = instr->ArgumentAt(0)->constant_value();
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const Object& o2 = instr->ArgumentAt(1)->constant_value();
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if (IsConstant(o1) && IsConstant(o2) && o1.IsString() && o2.IsString()) {
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SetValue(instr, Bool::Get(String::Cast(o1).Equals(String::Cast(o2))));
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return;
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}
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break;
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}
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case MethodRecognizer::kStringBaseLength:
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case MethodRecognizer::kStringBaseIsEmpty: {
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ASSERT(instr->FirstArgIndex() == 0);
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// Otherwise evaluate string length with propagated constants.
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const Object& o = instr->ArgumentAt(0)->constant_value();
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if (IsConstant(o) && o.IsString()) {
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const auto& str = String::Cast(o);
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if (kind == MethodRecognizer::kStringBaseLength) {
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SetValue(instr, Integer::ZoneHandle(Z, Integer::New(str.Length())));
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} else {
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SetValue(instr, Bool::Get(str.Length() == 0));
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}
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return;
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}
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break;
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}
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default:
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break;
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}
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SetValue(instr, non_constant_);
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}
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void ConstantPropagator::VisitLoadLocal(LoadLocalInstr* instr) {
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// Instruction is eliminated when translating to SSA.
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UNREACHABLE();
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|
}
|
|
|
|
void ConstantPropagator::VisitDropTemps(DropTempsInstr* instr) {
|
|
// Instruction is eliminated when translating to SSA.
|
|
UNREACHABLE();
|
|
}
|
|
|
|
void ConstantPropagator::VisitMakeTemp(MakeTempInstr* instr) {
|
|
// Instruction is eliminated when translating to SSA.
|
|
UNREACHABLE();
|
|
}
|
|
|
|
void ConstantPropagator::VisitStoreLocal(StoreLocalInstr* instr) {
|
|
// Instruction is eliminated when translating to SSA.
|
|
UNREACHABLE();
|
|
}
|
|
|
|
void ConstantPropagator::VisitIfThenElse(IfThenElseInstr* instr) {
|
|
instr->comparison()->Accept(this);
|
|
const Object& value = instr->comparison()->constant_value();
|
|
if (IsNonConstant(value)) {
|
|
SetValue(instr, non_constant_);
|
|
} else if (IsConstant(value)) {
|
|
ASSERT(!value.IsNull());
|
|
ASSERT(value.IsBool());
|
|
bool result = Bool::Cast(value).value();
|
|
SetValue(instr, Smi::Handle(Z, Smi::New(result ? instr->if_true()
|
|
: instr->if_false())));
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitStrictCompare(StrictCompareInstr* instr) {
|
|
Definition* left_defn = instr->left()->definition();
|
|
Definition* right_defn = instr->right()->definition();
|
|
|
|
Definition* unwrapped_left_defn = UnwrapPhi(left_defn);
|
|
Definition* unwrapped_right_defn = UnwrapPhi(right_defn);
|
|
if (unwrapped_left_defn == unwrapped_right_defn) {
|
|
// Fold x === x, and x !== x to true/false.
|
|
SetValue(instr, Bool::Get(instr->kind() == Token::kEQ_STRICT));
|
|
if (unwrapped_left_defn != left_defn) {
|
|
MarkPhi(left_defn);
|
|
}
|
|
if (unwrapped_right_defn != right_defn) {
|
|
MarkPhi(right_defn);
|
|
}
|
|
return;
|
|
}
|
|
|
|
const Object& left = left_defn->constant_value();
|
|
const Object& right = right_defn->constant_value();
|
|
if (IsNonConstant(left) || IsNonConstant(right)) {
|
|
// TODO(vegorov): incorporate nullability information into the lattice.
|
|
if ((left.IsNull() && instr->right()->Type()->HasDecidableNullability()) ||
|
|
(right.IsNull() && instr->left()->Type()->HasDecidableNullability())) {
|
|
bool result = left.IsNull() ? instr->right()->Type()->IsNull()
|
|
: instr->left()->Type()->IsNull();
|
|
if (instr->kind() == Token::kNE_STRICT) {
|
|
result = !result;
|
|
}
|
|
SetValue(instr, Bool::Get(result));
|
|
} else {
|
|
const intptr_t left_cid = instr->left()->Type()->ToCid();
|
|
const intptr_t right_cid = instr->right()->Type()->ToCid();
|
|
// If exact classes (cids) are known and they differ, the result
|
|
// of strict compare can be computed.
|
|
if ((left_cid != kDynamicCid) && (right_cid != kDynamicCid) &&
|
|
(left_cid != right_cid)) {
|
|
const bool result = (instr->kind() != Token::kEQ_STRICT);
|
|
SetValue(instr, Bool::Get(result));
|
|
} else {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
} else if (IsConstant(left) && IsConstant(right)) {
|
|
bool result = IsIdenticalConstants(left, right);
|
|
if (instr->kind() == Token::kNE_STRICT) {
|
|
result = !result;
|
|
}
|
|
SetValue(instr, Bool::Get(result));
|
|
}
|
|
}
|
|
|
|
static bool CompareIntegers(Token::Kind kind,
|
|
const Integer& left,
|
|
const Integer& right) {
|
|
const int result = left.CompareWith(right);
|
|
switch (kind) {
|
|
case Token::kEQ:
|
|
return (result == 0);
|
|
case Token::kNE:
|
|
return (result != 0);
|
|
case Token::kLT:
|
|
return (result < 0);
|
|
case Token::kGT:
|
|
return (result > 0);
|
|
case Token::kLTE:
|
|
return (result <= 0);
|
|
case Token::kGTE:
|
|
return (result >= 0);
|
|
default:
|
|
UNREACHABLE();
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// Comparison instruction that is equivalent to the (left & right) == 0
|
|
// comparison pattern.
|
|
void ConstantPropagator::VisitTestSmi(TestSmiInstr* instr) {
|
|
const Object& left = instr->left()->definition()->constant_value();
|
|
const Object& right = instr->right()->definition()->constant_value();
|
|
if (IsNonConstant(left) || IsNonConstant(right)) {
|
|
SetValue(instr, non_constant_);
|
|
} else if (IsConstant(left) && IsConstant(right)) {
|
|
if (left.IsInteger() && right.IsInteger()) {
|
|
const bool result = CompareIntegers(
|
|
instr->kind(),
|
|
Integer::Handle(Z, Integer::Cast(left).BitOp(Token::kBIT_AND,
|
|
Integer::Cast(right))),
|
|
Smi::Handle(Z, Smi::New(0)));
|
|
SetValue(instr, result ? Bool::True() : Bool::False());
|
|
} else {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitTestCids(TestCidsInstr* instr) {
|
|
// TODO(sra): Constant fold test.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitEqualityCompare(EqualityCompareInstr* instr) {
|
|
Definition* left_defn = instr->left()->definition();
|
|
Definition* right_defn = instr->right()->definition();
|
|
|
|
if (RawObject::IsIntegerClassId(instr->operation_cid())) {
|
|
// Fold x == x, and x != x to true/false for numbers comparisons.
|
|
Definition* unwrapped_left_defn = UnwrapPhi(left_defn);
|
|
Definition* unwrapped_right_defn = UnwrapPhi(right_defn);
|
|
if (unwrapped_left_defn == unwrapped_right_defn) {
|
|
// Fold x === x, and x !== x to true/false.
|
|
SetValue(instr, Bool::Get(instr->kind() == Token::kEQ));
|
|
if (unwrapped_left_defn != left_defn) {
|
|
MarkPhi(left_defn);
|
|
}
|
|
if (unwrapped_right_defn != right_defn) {
|
|
MarkPhi(right_defn);
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
|
|
const Object& left = left_defn->constant_value();
|
|
const Object& right = right_defn->constant_value();
|
|
if (IsNonConstant(left) || IsNonConstant(right)) {
|
|
SetValue(instr, non_constant_);
|
|
} else if (IsConstant(left) && IsConstant(right)) {
|
|
if (left.IsInteger() && right.IsInteger()) {
|
|
const bool result = CompareIntegers(instr->kind(), Integer::Cast(left),
|
|
Integer::Cast(right));
|
|
SetValue(instr, Bool::Get(result));
|
|
} else if (left.IsString() && right.IsString()) {
|
|
const bool result = String::Cast(left).Equals(String::Cast(right));
|
|
SetValue(instr, Bool::Get((instr->kind() == Token::kEQ) == result));
|
|
} else {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitRelationalOp(RelationalOpInstr* instr) {
|
|
const Object& left = instr->left()->definition()->constant_value();
|
|
const Object& right = instr->right()->definition()->constant_value();
|
|
if (IsNonConstant(left) || IsNonConstant(right)) {
|
|
SetValue(instr, non_constant_);
|
|
} else if (IsConstant(left) && IsConstant(right)) {
|
|
if (left.IsInteger() && right.IsInteger()) {
|
|
const bool result = CompareIntegers(instr->kind(), Integer::Cast(left),
|
|
Integer::Cast(right));
|
|
SetValue(instr, Bool::Get(result));
|
|
} else if (left.IsDouble() && right.IsDouble()) {
|
|
// TODO(srdjan): Implement.
|
|
SetValue(instr, non_constant_);
|
|
} else {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitNativeCall(NativeCallInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitFfiCall(FfiCallInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitDebugStepCheck(DebugStepCheckInstr* instr) {
|
|
// Nothing to do.
|
|
}
|
|
|
|
void ConstantPropagator::VisitOneByteStringFromCharCode(
|
|
OneByteStringFromCharCodeInstr* instr) {
|
|
const Object& o = instr->char_code()->definition()->constant_value();
|
|
if (o.IsNull() || IsNonConstant(o)) {
|
|
SetValue(instr, non_constant_);
|
|
} else if (IsConstant(o)) {
|
|
const intptr_t ch_code = Smi::Cast(o).Value();
|
|
ASSERT(ch_code >= 0);
|
|
if (ch_code < Symbols::kMaxOneCharCodeSymbol) {
|
|
RawString** table = Symbols::PredefinedAddress();
|
|
SetValue(instr, String::ZoneHandle(Z, table[ch_code]));
|
|
} else {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitStringToCharCode(StringToCharCodeInstr* instr) {
|
|
const Object& o = instr->str()->definition()->constant_value();
|
|
if (o.IsNull() || IsNonConstant(o)) {
|
|
SetValue(instr, non_constant_);
|
|
} else if (IsConstant(o)) {
|
|
const String& str = String::Cast(o);
|
|
const intptr_t result =
|
|
(str.Length() == 1) ? static_cast<intptr_t>(str.CharAt(0)) : -1;
|
|
SetValue(instr, Smi::ZoneHandle(Z, Smi::New(result)));
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitStringInterpolate(StringInterpolateInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitLoadIndexed(LoadIndexedInstr* instr) {
|
|
const Object& array_obj = instr->array()->definition()->constant_value();
|
|
const Object& index_obj = instr->index()->definition()->constant_value();
|
|
if (IsNonConstant(array_obj) || IsNonConstant(index_obj)) {
|
|
SetValue(instr, non_constant_);
|
|
} else if (IsConstant(array_obj) && IsConstant(index_obj)) {
|
|
// Need index to be Smi and array to be either String or an immutable array.
|
|
if (!index_obj.IsSmi()) {
|
|
// Should not occur.
|
|
SetValue(instr, non_constant_);
|
|
return;
|
|
}
|
|
const intptr_t index = Smi::Cast(index_obj).Value();
|
|
if (index >= 0) {
|
|
if (array_obj.IsString()) {
|
|
const String& str = String::Cast(array_obj);
|
|
if (str.Length() > index) {
|
|
SetValue(instr,
|
|
Smi::Handle(
|
|
Z, Smi::New(static_cast<intptr_t>(str.CharAt(index)))));
|
|
return;
|
|
}
|
|
} else if (array_obj.IsArray()) {
|
|
const Array& a = Array::Cast(array_obj);
|
|
if ((a.Length() > index) && a.IsImmutable()) {
|
|
Instance& result = Instance::Handle(Z);
|
|
result ^= a.At(index);
|
|
SetValue(instr, result);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitLoadCodeUnits(LoadCodeUnitsInstr* instr) {
|
|
// TODO(zerny): Implement constant propagation.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitLoadIndexedUnsafe(LoadIndexedUnsafeInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitInitStaticField(InitStaticFieldInstr* instr) {
|
|
// Nothing to do.
|
|
}
|
|
|
|
void ConstantPropagator::VisitLoadStaticField(LoadStaticFieldInstr* instr) {
|
|
if (!FLAG_fields_may_be_reset) {
|
|
const Field& field = instr->StaticField();
|
|
ASSERT(field.is_static());
|
|
Instance& obj = Instance::Handle(Z, field.StaticValue());
|
|
if (field.is_final() && (obj.raw() != Object::sentinel().raw()) &&
|
|
(obj.raw() != Object::transition_sentinel().raw())) {
|
|
if (obj.IsSmi() || obj.IsOld()) {
|
|
SetValue(instr, obj);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitStoreStaticField(StoreStaticFieldInstr* instr) {
|
|
SetValue(instr, instr->value()->definition()->constant_value());
|
|
}
|
|
|
|
void ConstantPropagator::VisitBooleanNegate(BooleanNegateInstr* instr) {
|
|
const Object& value = instr->value()->definition()->constant_value();
|
|
if (IsNonConstant(value)) {
|
|
SetValue(instr, non_constant_);
|
|
} else if (IsConstant(value)) {
|
|
bool val = value.raw() != Bool::True().raw();
|
|
SetValue(instr, Bool::Get(val));
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitInstanceOf(InstanceOfInstr* instr) {
|
|
Definition* def = instr->value()->definition();
|
|
const Object& value = def->constant_value();
|
|
const AbstractType& checked_type = instr->type();
|
|
if (checked_type.IsTopType()) {
|
|
SetValue(instr, Bool::True());
|
|
} else if (IsNonConstant(value)) {
|
|
intptr_t value_cid = instr->value()->definition()->Type()->ToCid();
|
|
Representation rep = def->representation();
|
|
if ((checked_type.IsFloat32x4Type() && (rep == kUnboxedFloat32x4)) ||
|
|
(checked_type.IsInt32x4Type() && (rep == kUnboxedInt32x4)) ||
|
|
(checked_type.IsDoubleType() && (rep == kUnboxedDouble) &&
|
|
FlowGraphCompiler::SupportsUnboxedDoubles()) ||
|
|
(checked_type.IsIntType() && (rep == kUnboxedInt64))) {
|
|
// Ensure that compile time type matches representation.
|
|
ASSERT(((rep == kUnboxedFloat32x4) && (value_cid == kFloat32x4Cid)) ||
|
|
((rep == kUnboxedInt32x4) && (value_cid == kInt32x4Cid)) ||
|
|
((rep == kUnboxedDouble) && (value_cid == kDoubleCid)) ||
|
|
((rep == kUnboxedInt64) && (value_cid == kMintCid)));
|
|
// The representation guarantees the type check to be true.
|
|
SetValue(instr, Bool::True());
|
|
} else {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
} else if (IsConstant(value)) {
|
|
if (value.IsInstance()) {
|
|
const Instance& instance = Instance::Cast(value);
|
|
if (instr->instantiator_type_arguments()->BindsToConstantNull() &&
|
|
instr->function_type_arguments()->BindsToConstantNull()) {
|
|
bool is_instance =
|
|
instance.IsInstanceOf(checked_type, Object::null_type_arguments(),
|
|
Object::null_type_arguments());
|
|
SetValue(instr, Bool::Get(is_instance));
|
|
return;
|
|
}
|
|
}
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitCreateArray(CreateArrayInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitAllocateObject(AllocateObjectInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitLoadUntagged(LoadUntaggedInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitLoadClassId(LoadClassIdInstr* instr) {
|
|
// This first part duplicates the work done in LoadClassIdInstr::Canonicalize,
|
|
// which replaces uses of LoadClassIdInstr where the object has a concrete
|
|
// type with a Constant. Canonicalize runs before the ConstantPropagation
|
|
// pass, so if that was all, this wouldn't be needed.
|
|
//
|
|
// However, the ConstantPropagator also runs as part of OptimizeBranches, and
|
|
// TypePropagation runs between it and the previous Canonicalize. Thus, the
|
|
// type may have become concrete and we should take that into account. Not
|
|
// doing so led to some benchmark regressions.
|
|
intptr_t cid = instr->object()->Type()->ToCid();
|
|
if (cid != kDynamicCid) {
|
|
SetValue(instr, Smi::ZoneHandle(Z, Smi::New(cid)));
|
|
return;
|
|
}
|
|
const Object& object = instr->object()->definition()->constant_value();
|
|
if (IsConstant(object)) {
|
|
cid = object.GetClassId();
|
|
SetValue(instr, Smi::ZoneHandle(Z, Smi::New(cid)));
|
|
return;
|
|
}
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitLoadField(LoadFieldInstr* instr) {
|
|
Value* instance = instr->instance();
|
|
if ((instr->slot().kind() == Slot::Kind::kArray_length) &&
|
|
instance->definition()->OriginalDefinition()->IsCreateArray()) {
|
|
Value* num_elements = instance->definition()
|
|
->OriginalDefinition()
|
|
->AsCreateArray()
|
|
->num_elements();
|
|
if (num_elements->BindsToConstant() &&
|
|
num_elements->BoundConstant().IsSmi()) {
|
|
intptr_t length = Smi::Cast(num_elements->BoundConstant()).Value();
|
|
const Object& result = Smi::ZoneHandle(Z, Smi::New(length));
|
|
SetValue(instr, result);
|
|
return;
|
|
}
|
|
}
|
|
|
|
const Object& constant = instance->definition()->constant_value();
|
|
if (IsConstant(constant)) {
|
|
if (instr->IsImmutableLengthLoad()) {
|
|
if (constant.IsString()) {
|
|
SetValue(instr,
|
|
Smi::ZoneHandle(Z, Smi::New(String::Cast(constant).Length())));
|
|
return;
|
|
}
|
|
if (constant.IsArray()) {
|
|
SetValue(instr,
|
|
Smi::ZoneHandle(Z, Smi::New(Array::Cast(constant).Length())));
|
|
return;
|
|
}
|
|
if (constant.IsTypedData()) {
|
|
SetValue(instr, Smi::ZoneHandle(
|
|
Z, Smi::New(TypedData::Cast(constant).Length())));
|
|
return;
|
|
}
|
|
} else {
|
|
Object& value = Object::Handle();
|
|
if (instr->Evaluate(constant, &value)) {
|
|
SetValue(instr, Object::ZoneHandle(Z, value.raw()));
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitInstantiateType(InstantiateTypeInstr* instr) {
|
|
const Object& object =
|
|
instr->instantiator_type_arguments()->definition()->constant_value();
|
|
if (IsNonConstant(object)) {
|
|
SetValue(instr, non_constant_);
|
|
return;
|
|
}
|
|
if (IsConstant(object)) {
|
|
if (instr->type().IsTypeParameter() &&
|
|
TypeParameter::Cast(instr->type()).IsClassTypeParameter()) {
|
|
if (object.IsNull()) {
|
|
SetValue(instr, Object::dynamic_type());
|
|
return;
|
|
}
|
|
// We could try to instantiate the type parameter and return it if no
|
|
// malformed error is reported.
|
|
}
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
// TODO(regis): We can do the same as above for a function type parameter.
|
|
// Better: If both instantiator type arguments and function type arguments are
|
|
// constant, instantiate the type if no bound error is reported.
|
|
}
|
|
|
|
void ConstantPropagator::VisitInstantiateTypeArguments(
|
|
InstantiateTypeArgumentsInstr* instr) {
|
|
const Object& instantiator_type_args =
|
|
instr->instantiator_type_arguments()->definition()->constant_value();
|
|
const Object& function_type_args =
|
|
instr->function_type_arguments()->definition()->constant_value();
|
|
if (IsNonConstant(instantiator_type_args) ||
|
|
IsNonConstant(function_type_args)) {
|
|
SetValue(instr, non_constant_);
|
|
return;
|
|
}
|
|
if (IsConstant(instantiator_type_args) && IsConstant(function_type_args)) {
|
|
if (instantiator_type_args.IsNull() && function_type_args.IsNull()) {
|
|
const intptr_t len = instr->type_arguments().Length();
|
|
if (instr->type_arguments().IsRawWhenInstantiatedFromRaw(len)) {
|
|
SetValue(instr, instantiator_type_args);
|
|
return;
|
|
}
|
|
}
|
|
if (instr->type_arguments().CanShareInstantiatorTypeArguments(
|
|
instr->instantiator_class())) {
|
|
SetValue(instr, instantiator_type_args);
|
|
return;
|
|
}
|
|
if (instr->type_arguments().CanShareFunctionTypeArguments(
|
|
instr->function())) {
|
|
SetValue(instr, function_type_args);
|
|
return;
|
|
}
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
// TODO(regis): If both instantiator type arguments and function type
|
|
// arguments are constant, instantiate the type arguments if no bound error
|
|
// is reported.
|
|
// TODO(regis): If either instantiator type arguments or function type
|
|
// arguments are constant null, check
|
|
// type_arguments().IsRawWhenInstantiatedFromRaw() separately for each
|
|
// genericity.
|
|
}
|
|
|
|
void ConstantPropagator::VisitAllocateContext(AllocateContextInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitAllocateUninitializedContext(
|
|
AllocateUninitializedContextInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitCloneContext(CloneContextInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitBinaryIntegerOp(BinaryIntegerOpInstr* binary_op) {
|
|
const Object& left = binary_op->left()->definition()->constant_value();
|
|
const Object& right = binary_op->right()->definition()->constant_value();
|
|
if (IsConstant(left) && IsConstant(right)) {
|
|
if (left.IsInteger() && right.IsInteger()) {
|
|
const Integer& left_int = Integer::Cast(left);
|
|
const Integer& right_int = Integer::Cast(right);
|
|
const Integer& result =
|
|
Integer::Handle(Z, binary_op->Evaluate(left_int, right_int));
|
|
if (!result.IsNull()) {
|
|
SetValue(binary_op, Integer::ZoneHandle(Z, result.raw()));
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
SetValue(binary_op, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitCheckedSmiOp(CheckedSmiOpInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitCheckedSmiComparison(
|
|
CheckedSmiComparisonInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitBinarySmiOp(BinarySmiOpInstr* instr) {
|
|
VisitBinaryIntegerOp(instr);
|
|
}
|
|
|
|
void ConstantPropagator::VisitBinaryInt32Op(BinaryInt32OpInstr* instr) {
|
|
VisitBinaryIntegerOp(instr);
|
|
}
|
|
|
|
void ConstantPropagator::VisitBinaryUint32Op(BinaryUint32OpInstr* instr) {
|
|
VisitBinaryIntegerOp(instr);
|
|
}
|
|
|
|
void ConstantPropagator::VisitBinaryInt64Op(BinaryInt64OpInstr* instr) {
|
|
VisitBinaryIntegerOp(instr);
|
|
}
|
|
|
|
void ConstantPropagator::VisitShiftInt64Op(ShiftInt64OpInstr* instr) {
|
|
VisitBinaryIntegerOp(instr);
|
|
}
|
|
|
|
void ConstantPropagator::VisitSpeculativeShiftInt64Op(
|
|
SpeculativeShiftInt64OpInstr* instr) {
|
|
VisitBinaryIntegerOp(instr);
|
|
}
|
|
|
|
void ConstantPropagator::VisitShiftUint32Op(ShiftUint32OpInstr* instr) {
|
|
VisitBinaryIntegerOp(instr);
|
|
}
|
|
|
|
void ConstantPropagator::VisitSpeculativeShiftUint32Op(
|
|
SpeculativeShiftUint32OpInstr* instr) {
|
|
VisitBinaryIntegerOp(instr);
|
|
}
|
|
|
|
void ConstantPropagator::VisitBoxInt64(BoxInt64Instr* instr) {
|
|
// TODO(kmillikin): Handle box operation.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitUnboxInt64(UnboxInt64Instr* instr) {
|
|
// TODO(kmillikin): Handle unbox operation.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitUnaryIntegerOp(UnaryIntegerOpInstr* unary_op) {
|
|
const Object& value = unary_op->value()->definition()->constant_value();
|
|
if (IsConstant(value) && value.IsInteger()) {
|
|
const Integer& value_int = Integer::Cast(value);
|
|
const Integer& result = Integer::Handle(Z, unary_op->Evaluate(value_int));
|
|
if (!result.IsNull()) {
|
|
SetValue(unary_op, Integer::ZoneHandle(Z, result.raw()));
|
|
return;
|
|
}
|
|
}
|
|
|
|
SetValue(unary_op, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitUnaryInt64Op(UnaryInt64OpInstr* instr) {
|
|
VisitUnaryIntegerOp(instr);
|
|
}
|
|
|
|
void ConstantPropagator::VisitUnarySmiOp(UnarySmiOpInstr* instr) {
|
|
VisitUnaryIntegerOp(instr);
|
|
}
|
|
|
|
void ConstantPropagator::VisitUnaryDoubleOp(UnaryDoubleOpInstr* instr) {
|
|
const Object& value = instr->value()->definition()->constant_value();
|
|
if (IsNonConstant(value)) {
|
|
SetValue(instr, non_constant_);
|
|
} else if (IsConstant(value)) {
|
|
// TODO(kmillikin): Handle unary operations.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitSmiToDouble(SmiToDoubleInstr* instr) {
|
|
const Object& value = instr->value()->definition()->constant_value();
|
|
if (IsConstant(value) && value.IsInteger()) {
|
|
SetValue(instr,
|
|
Double::Handle(Z, Double::New(Integer::Cast(value).AsDoubleValue(),
|
|
Heap::kOld)));
|
|
} else if (!IsUnknown(value)) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitInt64ToDouble(Int64ToDoubleInstr* instr) {
|
|
const Object& value = instr->value()->definition()->constant_value();
|
|
if (IsConstant(value) && value.IsInteger()) {
|
|
SetValue(instr,
|
|
Double::Handle(Z, Double::New(Integer::Cast(value).AsDoubleValue(),
|
|
Heap::kOld)));
|
|
} else if (!IsUnknown(value)) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitInt32ToDouble(Int32ToDoubleInstr* instr) {
|
|
const Object& value = instr->value()->definition()->constant_value();
|
|
if (IsConstant(value) && value.IsInteger()) {
|
|
SetValue(instr,
|
|
Double::Handle(Z, Double::New(Integer::Cast(value).AsDoubleValue(),
|
|
Heap::kOld)));
|
|
} else if (!IsUnknown(value)) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitDoubleToInteger(DoubleToIntegerInstr* instr) {
|
|
// TODO(kmillikin): Handle conversion.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitDoubleToSmi(DoubleToSmiInstr* instr) {
|
|
// TODO(kmillikin): Handle conversion.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitDoubleToDouble(DoubleToDoubleInstr* instr) {
|
|
// TODO(kmillikin): Handle conversion.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitDoubleToFloat(DoubleToFloatInstr* instr) {
|
|
// TODO(kmillikin): Handle conversion.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitFloatToDouble(FloatToDoubleInstr* instr) {
|
|
// TODO(kmillikin): Handle conversion.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitInvokeMathCFunction(
|
|
InvokeMathCFunctionInstr* instr) {
|
|
// TODO(kmillikin): Handle conversion.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitTruncDivMod(TruncDivModInstr* instr) {
|
|
// TODO(srdjan): Handle merged instruction.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitExtractNthOutput(ExtractNthOutputInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitConstant(ConstantInstr* instr) {
|
|
SetValue(instr, instr->value());
|
|
}
|
|
|
|
void ConstantPropagator::VisitUnboxedConstant(UnboxedConstantInstr* instr) {
|
|
SetValue(instr, instr->value());
|
|
}
|
|
|
|
void ConstantPropagator::VisitConstraint(ConstraintInstr* instr) {
|
|
// Should not be used outside of range analysis.
|
|
UNREACHABLE();
|
|
}
|
|
|
|
void ConstantPropagator::VisitMaterializeObject(MaterializeObjectInstr* instr) {
|
|
// Should not be used outside of allocation elimination pass.
|
|
UNREACHABLE();
|
|
}
|
|
|
|
static bool IsIntegerOrDouble(const Object& value) {
|
|
return value.IsInteger() || value.IsDouble();
|
|
}
|
|
|
|
static double ToDouble(const Object& value) {
|
|
return value.IsInteger() ? Integer::Cast(value).AsDoubleValue()
|
|
: Double::Cast(value).value();
|
|
}
|
|
|
|
void ConstantPropagator::VisitBinaryDoubleOp(BinaryDoubleOpInstr* instr) {
|
|
const Object& left = instr->left()->definition()->constant_value();
|
|
const Object& right = instr->right()->definition()->constant_value();
|
|
if (IsNonConstant(left) || IsNonConstant(right)) {
|
|
SetValue(instr, non_constant_);
|
|
} else if (left.IsInteger() && right.IsInteger()) {
|
|
SetValue(instr, non_constant_);
|
|
} else if (IsIntegerOrDouble(left) && IsIntegerOrDouble(right)) {
|
|
const double left_val = ToDouble(left);
|
|
const double right_val = ToDouble(right);
|
|
double result_val = 0.0;
|
|
switch (instr->op_kind()) {
|
|
case Token::kADD:
|
|
result_val = left_val + right_val;
|
|
break;
|
|
case Token::kSUB:
|
|
result_val = left_val - right_val;
|
|
break;
|
|
case Token::kMUL:
|
|
result_val = left_val * right_val;
|
|
break;
|
|
case Token::kDIV:
|
|
result_val = left_val / right_val;
|
|
break;
|
|
default:
|
|
UNREACHABLE();
|
|
}
|
|
const Double& result = Double::ZoneHandle(Double::NewCanonical(result_val));
|
|
SetValue(instr, result);
|
|
} else if (IsConstant(left) && IsConstant(right)) {
|
|
// Both values known, but no rule to evaluate this further.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitDoubleTestOp(DoubleTestOpInstr* instr) {
|
|
const Object& value = instr->value()->definition()->constant_value();
|
|
const bool is_negated = instr->kind() != Token::kEQ;
|
|
if (value.IsInteger()) {
|
|
SetValue(instr, is_negated ? Bool::True() : Bool::False());
|
|
} else if (IsIntegerOrDouble(value)) {
|
|
switch (instr->op_kind()) {
|
|
case MethodRecognizer::kDouble_getIsNaN: {
|
|
const bool is_nan = isnan(ToDouble(value));
|
|
SetValue(instr, Bool::Get(is_negated ? !is_nan : is_nan));
|
|
break;
|
|
}
|
|
case MethodRecognizer::kDouble_getIsInfinite: {
|
|
const bool is_inf = isinf(ToDouble(value));
|
|
SetValue(instr, Bool::Get(is_negated ? !is_inf : is_inf));
|
|
break;
|
|
}
|
|
default:
|
|
UNREACHABLE();
|
|
}
|
|
} else {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitSimdOp(SimdOpInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitMathUnary(MathUnaryInstr* instr) {
|
|
const Object& value = instr->value()->definition()->constant_value();
|
|
if (IsNonConstant(value)) {
|
|
SetValue(instr, non_constant_);
|
|
} else if (IsConstant(value)) {
|
|
// TODO(kmillikin): Handle Math's unary operations (sqrt, cos, sin).
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitMathMinMax(MathMinMaxInstr* instr) {
|
|
const Object& left = instr->left()->definition()->constant_value();
|
|
const Object& right = instr->right()->definition()->constant_value();
|
|
if (IsNonConstant(left) || IsNonConstant(right)) {
|
|
SetValue(instr, non_constant_);
|
|
} else if (IsConstant(left) && IsConstant(right)) {
|
|
// TODO(srdjan): Handle min and max.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitCaseInsensitiveCompare(
|
|
CaseInsensitiveCompareInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitUnbox(UnboxInstr* instr) {
|
|
const Object& value = instr->value()->definition()->constant_value();
|
|
if (IsNonConstant(value)) {
|
|
SetValue(instr, non_constant_);
|
|
} else if (IsConstant(value)) {
|
|
// TODO(kmillikin): Handle conversion.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitBox(BoxInstr* instr) {
|
|
const Object& value = instr->value()->definition()->constant_value();
|
|
if (IsNonConstant(value)) {
|
|
SetValue(instr, non_constant_);
|
|
} else if (IsConstant(value)) {
|
|
// TODO(kmillikin): Handle conversion.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::VisitBoxUint32(BoxUint32Instr* instr) {
|
|
// TODO(kmillikin): Handle box operation.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitUnboxUint32(UnboxUint32Instr* instr) {
|
|
// TODO(kmillikin): Handle unbox operation.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitBoxInt32(BoxInt32Instr* instr) {
|
|
// TODO(kmillikin): Handle box operation.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitUnboxInt32(UnboxInt32Instr* instr) {
|
|
// TODO(kmillikin): Handle unbox operation.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitIntConverter(IntConverterInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitUnboxedWidthExtender(
|
|
UnboxedWidthExtenderInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitBitCast(BitCastInstr* instr) {
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::VisitUnaryUint32Op(UnaryUint32OpInstr* instr) {
|
|
// TODO(kmillikin): Handle unary operations.
|
|
SetValue(instr, non_constant_);
|
|
}
|
|
|
|
void ConstantPropagator::Analyze() {
|
|
GraphEntryInstr* entry = graph_->graph_entry();
|
|
reachable_->Add(entry->preorder_number());
|
|
block_worklist_.Add(entry);
|
|
|
|
while (true) {
|
|
if (block_worklist_.is_empty()) {
|
|
if (definition_worklist_.IsEmpty()) break;
|
|
Definition* definition = definition_worklist_.RemoveLast();
|
|
for (Value* use = definition->input_use_list(); use != nullptr;
|
|
use = use->next_use()) {
|
|
use->instruction()->Accept(this);
|
|
}
|
|
} else {
|
|
BlockEntryInstr* block = block_worklist_.RemoveLast();
|
|
block->Accept(this);
|
|
}
|
|
}
|
|
}
|
|
|
|
static bool IsEmptyBlock(BlockEntryInstr* block) {
|
|
return block->next()->IsGoto() &&
|
|
(!block->IsJoinEntry() || (block->AsJoinEntry()->phis() == NULL)) &&
|
|
!block->IsIndirectEntry();
|
|
}
|
|
|
|
// Traverses a chain of empty blocks and returns the first reachable non-empty
|
|
// block that is not dominated by the start block. The empty blocks are added
|
|
// to the supplied bit vector.
|
|
static BlockEntryInstr* FindFirstNonEmptySuccessor(TargetEntryInstr* block,
|
|
BitVector* empty_blocks) {
|
|
BlockEntryInstr* current = block;
|
|
while (IsEmptyBlock(current) && block->Dominates(current)) {
|
|
ASSERT(!block->IsJoinEntry() || (block->AsJoinEntry()->phis() == NULL));
|
|
empty_blocks->Add(current->preorder_number());
|
|
current = current->next()->AsGoto()->successor();
|
|
}
|
|
return current;
|
|
}
|
|
|
|
void ConstantPropagator::EliminateRedundantBranches() {
|
|
// Canonicalize branches that have no side-effects and where true- and
|
|
// false-targets are the same.
|
|
bool changed = false;
|
|
BitVector* empty_blocks = new (Z) BitVector(Z, graph_->preorder().length());
|
|
for (BlockIterator b = graph_->postorder_iterator(); !b.Done(); b.Advance()) {
|
|
BlockEntryInstr* block = b.Current();
|
|
BranchInstr* branch = block->last_instruction()->AsBranch();
|
|
empty_blocks->Clear();
|
|
if ((branch != NULL) && !branch->HasUnknownSideEffects()) {
|
|
ASSERT(branch->previous() != NULL); // Not already eliminated.
|
|
BlockEntryInstr* if_true =
|
|
FindFirstNonEmptySuccessor(branch->true_successor(), empty_blocks);
|
|
BlockEntryInstr* if_false =
|
|
FindFirstNonEmptySuccessor(branch->false_successor(), empty_blocks);
|
|
if (if_true == if_false) {
|
|
// Replace the branch with a jump to the common successor.
|
|
// Drop the comparison, which does not have side effects
|
|
JoinEntryInstr* join = if_true->AsJoinEntry();
|
|
if (join->phis() == NULL) {
|
|
GotoInstr* jump =
|
|
new (Z) GotoInstr(if_true->AsJoinEntry(), DeoptId::kNone);
|
|
jump->InheritDeoptTarget(Z, branch);
|
|
|
|
Instruction* previous = branch->previous();
|
|
branch->set_previous(NULL);
|
|
previous->LinkTo(jump);
|
|
|
|
// Remove uses from branch and all the empty blocks that
|
|
// are now unreachable.
|
|
branch->UnuseAllInputs();
|
|
for (BitVector::Iterator it(empty_blocks); !it.Done(); it.Advance()) {
|
|
BlockEntryInstr* empty_block = graph_->preorder()[it.Current()];
|
|
empty_block->ClearAllInstructions();
|
|
}
|
|
|
|
changed = true;
|
|
|
|
if (FLAG_trace_constant_propagation && graph_->should_print()) {
|
|
THR_Print("Eliminated branch in B%" Pd " common target B%" Pd "\n",
|
|
block->block_id(), join->block_id());
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (changed) {
|
|
graph_->DiscoverBlocks();
|
|
// TODO(fschneider): Update dominator tree in place instead of recomputing.
|
|
GrowableArray<BitVector*> dominance_frontier;
|
|
graph_->ComputeDominators(&dominance_frontier);
|
|
}
|
|
}
|
|
|
|
static void RemovePushArguments(StaticCallInstr* call) {
|
|
for (intptr_t i = 0; i < call->ArgumentCount(); ++i) {
|
|
PushArgumentInstr* push = call->PushArgumentAt(i);
|
|
ASSERT(push->input_use_list() == nullptr); // no direct uses
|
|
push->ReplaceUsesWith(push->value()->definition()); // cleanup env uses
|
|
push->RemoveFromGraph();
|
|
}
|
|
}
|
|
|
|
void ConstantPropagator::Transform() {
|
|
// We will recompute dominators, block ordering, block ids, block last
|
|
// instructions, previous pointers, predecessors, etc. after eliminating
|
|
// unreachable code. We do not maintain those properties during the
|
|
// transformation.
|
|
auto& value = Object::Handle(Z);
|
|
for (BlockIterator b = graph_->reverse_postorder_iterator(); !b.Done();
|
|
b.Advance()) {
|
|
BlockEntryInstr* block = b.Current();
|
|
if (!reachable_->Contains(block->preorder_number())) {
|
|
if (FLAG_trace_constant_propagation && graph_->should_print()) {
|
|
THR_Print("Unreachable B%" Pd "\n", block->block_id());
|
|
}
|
|
// Remove all uses in unreachable blocks.
|
|
block->ClearAllInstructions();
|
|
continue;
|
|
}
|
|
|
|
JoinEntryInstr* join = block->AsJoinEntry();
|
|
if (join != NULL) {
|
|
// Remove phi inputs corresponding to unreachable predecessor blocks.
|
|
// Predecessors will be recomputed (in block id order) after removing
|
|
// unreachable code so we merely have to keep the phi inputs in order.
|
|
ZoneGrowableArray<PhiInstr*>* phis = join->phis();
|
|
if ((phis != NULL) && !phis->is_empty()) {
|
|
intptr_t pred_count = join->PredecessorCount();
|
|
intptr_t live_count = 0;
|
|
for (intptr_t pred_idx = 0; pred_idx < pred_count; ++pred_idx) {
|
|
if (reachable_->Contains(
|
|
join->PredecessorAt(pred_idx)->preorder_number())) {
|
|
if (live_count < pred_idx) {
|
|
for (PhiIterator it(join); !it.Done(); it.Advance()) {
|
|
PhiInstr* phi = it.Current();
|
|
ASSERT(phi != NULL);
|
|
phi->SetInputAt(live_count, phi->InputAt(pred_idx));
|
|
}
|
|
}
|
|
++live_count;
|
|
} else {
|
|
for (PhiIterator it(join); !it.Done(); it.Advance()) {
|
|
PhiInstr* phi = it.Current();
|
|
ASSERT(phi != NULL);
|
|
phi->InputAt(pred_idx)->RemoveFromUseList();
|
|
}
|
|
}
|
|
}
|
|
if (live_count < pred_count) {
|
|
intptr_t to_idx = 0;
|
|
for (intptr_t from_idx = 0; from_idx < phis->length(); ++from_idx) {
|
|
PhiInstr* phi = (*phis)[from_idx];
|
|
ASSERT(phi != NULL);
|
|
if (FLAG_remove_redundant_phis && (live_count == 1)) {
|
|
Value* input = phi->InputAt(0);
|
|
phi->ReplaceUsesWith(input->definition());
|
|
input->RemoveFromUseList();
|
|
} else {
|
|
phi->inputs_.TruncateTo(live_count);
|
|
(*phis)[to_idx++] = phi;
|
|
}
|
|
}
|
|
if (to_idx == 0) {
|
|
join->phis_ = NULL;
|
|
} else {
|
|
phis->TruncateTo(to_idx);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
for (ForwardInstructionIterator i(block); !i.Done(); i.Advance()) {
|
|
Definition* defn = i.Current()->AsDefinition();
|
|
// Replace constant-valued instructions without observable side
|
|
// effects. Do this for smis only to avoid having to copy other
|
|
// objects into the heap's old generation.
|
|
if ((defn != NULL) && IsConstant(defn->constant_value()) &&
|
|
(defn->constant_value().IsSmi() || defn->constant_value().IsOld()) &&
|
|
!defn->IsConstant() && !defn->IsPushArgument() &&
|
|
!defn->IsStoreIndexed() && !defn->IsStoreInstanceField() &&
|
|
!defn->IsStoreStaticField()) {
|
|
if (FLAG_trace_constant_propagation && graph_->should_print()) {
|
|
THR_Print("Constant v%" Pd " = %s\n", defn->ssa_temp_index(),
|
|
defn->constant_value().ToCString());
|
|
}
|
|
value = defn->constant_value().raw();
|
|
if ((value.IsString() || value.IsMint() || value.IsDouble()) &&
|
|
!value.IsCanonical()) {
|
|
const char* error_str = nullptr;
|
|
value = Instance::Cast(value).CheckAndCanonicalize(T, &error_str);
|
|
ASSERT(!value.IsNull() && (error_str == nullptr));
|
|
}
|
|
if (auto call = defn->AsStaticCall()) {
|
|
RemovePushArguments(call);
|
|
}
|
|
ConstantInstr* constant = graph_->GetConstant(value);
|
|
defn->ReplaceUsesWith(constant);
|
|
i.RemoveCurrentFromGraph();
|
|
}
|
|
}
|
|
|
|
// Replace branches where one target is unreachable with jumps.
|
|
BranchInstr* branch = block->last_instruction()->AsBranch();
|
|
if (branch != NULL) {
|
|
TargetEntryInstr* if_true = branch->true_successor();
|
|
TargetEntryInstr* if_false = branch->false_successor();
|
|
JoinEntryInstr* join = NULL;
|
|
Instruction* next = NULL;
|
|
|
|
if (!reachable_->Contains(if_true->preorder_number())) {
|
|
ASSERT(reachable_->Contains(if_false->preorder_number()));
|
|
ASSERT(if_false->parallel_move() == NULL);
|
|
join = new (Z) JoinEntryInstr(if_false->block_id(),
|
|
if_false->try_index(), DeoptId::kNone);
|
|
join->InheritDeoptTarget(Z, if_false);
|
|
if_false->UnuseAllInputs();
|
|
next = if_false->next();
|
|
} else if (!reachable_->Contains(if_false->preorder_number())) {
|
|
ASSERT(if_true->parallel_move() == NULL);
|
|
join = new (Z) JoinEntryInstr(if_true->block_id(), if_true->try_index(),
|
|
DeoptId::kNone);
|
|
join->InheritDeoptTarget(Z, if_true);
|
|
if_true->UnuseAllInputs();
|
|
next = if_true->next();
|
|
}
|
|
|
|
if (join != NULL) {
|
|
// Replace the branch with a jump to the reachable successor.
|
|
// Drop the comparison, which does not have side effects as long
|
|
// as it is a strict compare (the only one we can determine is
|
|
// constant with the current analysis).
|
|
GotoInstr* jump = new (Z) GotoInstr(join, DeoptId::kNone);
|
|
jump->InheritDeoptTarget(Z, branch);
|
|
|
|
Instruction* previous = branch->previous();
|
|
branch->set_previous(NULL);
|
|
previous->LinkTo(jump);
|
|
|
|
// Replace the false target entry with the new join entry. We will
|
|
// recompute the dominators after this pass.
|
|
join->LinkTo(next);
|
|
branch->UnuseAllInputs();
|
|
}
|
|
}
|
|
}
|
|
|
|
graph_->DiscoverBlocks();
|
|
graph_->MergeBlocks();
|
|
GrowableArray<BitVector*> dominance_frontier;
|
|
graph_->ComputeDominators(&dominance_frontier);
|
|
}
|
|
|
|
} // namespace dart
|
|
|
|
#endif // !defined(DART_PRECOMPILED_RUNTIME)
|