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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#ifndef jit_BytecodeAnalysis_h
#define jit_BytecodeAnalysis_h
#include "jit/JitAllocPolicy.h"
#include "js/Vector.h"
#include "vm/JSScript.h"
namespace js {
namespace jit {
// Basic information about bytecodes in the script. Used to help baseline
// compilation.
struct BytecodeInfo {
static const uint16_t MAX_STACK_DEPTH = 0xffffU;
uint16_t stackDepth;
bool initialized : 1;
bool jumpTarget : 1;
// If true, this is a JSOp::LoopHead where we can OSR into Ion/Warp code.
bool loopHeadCanOsr : 1;
// See the comment above normallyReachable in BytecodeAnalysis.cpp for how
// this works.
bool jumpTargetNormallyReachable : 1;
// True if the script has a resume offset for this bytecode op.
bool hasResumeOffset : 1;
void init(unsigned depth) {
MOZ_ASSERT(depth <= MAX_STACK_DEPTH);
MOZ_ASSERT_IF(initialized, stackDepth == depth);
initialized = true;
stackDepth = depth;
}
void setJumpTarget(bool normallyReachable) {
jumpTarget = true;
if (normallyReachable) {
jumpTargetNormallyReachable = true;
}
}
};
class BytecodeAnalysis {
JSScript* script_;
Vector<BytecodeInfo, 0, JitAllocPolicy> infos_;
public:
explicit BytecodeAnalysis(TempAllocator& alloc, JSScript* script);
[[nodiscard]] bool init(TempAllocator& alloc);
BytecodeInfo& info(jsbytecode* pc) {
uint32_t pcOffset = script_->pcToOffset(pc);
MOZ_ASSERT(infos_[pcOffset].initialized);
return infos_[pcOffset];
}
BytecodeInfo* maybeInfo(jsbytecode* pc) {
uint32_t pcOffset = script_->pcToOffset(pc);
if (infos_[pcOffset].initialized) {
return &infos_[pcOffset];
}
return nullptr;
}
void checkWarpSupport(JSOp op);
};
// Whether this script uses the frame's environment chain. The result is cached
// in JitScript and used by WarpBuilder.
bool ScriptUsesEnvironmentChain(JSScript* script);
} // namespace jit
} // namespace js
#endif /* jit_BytecodeAnalysis_h */