blob: c203e45cbd72805397bb48683a552ea899f1fe6d [file] [log] [blame]
// Copyright (c) 2020, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "platform/allocation.h"
namespace dart {
// Deoptimization Id logic.
// Deoptimization ids are used to refer to deoptimization points, at which
// control can enter unoptimized code from the optimized version of the code.
// Note: any instruction that does a call has two deoptimization points,
// one before the call and one after the call - so that we could deoptimize
// to either before or after the call depending on whether the same call
// already occured in the optimized code (and potentially produced
// observable side-effects) or not.
// To simplify implementation we always allocate two deopt ids (one for before
// point and one for the after point).
class DeoptId : public AllStatic {
static constexpr intptr_t kNone = -1;
static inline intptr_t Next(intptr_t deopt_id) { return deopt_id + kStep; }
static inline intptr_t ToDeoptAfter(intptr_t deopt_id) {
return deopt_id + kAfterOffset;
static inline bool IsDeoptBefore(intptr_t deopt_id) {
return (deopt_id % kStep) == kBeforeOffset;
static inline bool IsDeoptAfter(intptr_t deopt_id) {
return (deopt_id % kStep) == kAfterOffset;
static constexpr intptr_t kStep = 2;
static constexpr intptr_t kBeforeOffset = 0;
static constexpr intptr_t kAfterOffset = 1;
} // namespace dart