/* * Copyright (C) 2016 Apple Inc. All rights reserved. * Copyright (C) 2017 Yusuke Suzuki <utatane.tea@gmail.com>. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #pragma once #include "Reg.h" #include <wtf/Variant.h> #if ENABLE(JIT) namespace JSC { // It is quite unfortunate that 32 bit environment exists on DFG! This means that JSValueRegs contains 2 registers // in such an environment. If we use GPRReg and FPRReg in SnippetParams, SnippetParams may contain // different number of registers in 32bit and 64bit environments when we pass JSValueRegs, it is confusing. // Therefore, we introduce an abstraction that SnippetReg, which is a polymorphic register class. It can refer FPRReg, // GPRReg, and "JSValueRegs". Note that isGPR() will return false if the target Reg is "JSValueRegs" even if the // environment is 64bit. // // FIXME: Eventually we should move this class into JSC and make is available for other JIT code. // https://bugs.webkit.org/show_bug.cgi?id=162990 class SnippetReg { public: enum class Type : uint8_t { GPR = 0, FPR = 1, JSValue = 2, }; SnippetReg(GPRReg reg) : m_variant(reg) { } SnippetReg(FPRReg reg) : m_variant(reg) { } SnippetReg(JSValueRegs regs) : m_variant(regs) { } bool isGPR() const { return m_variant.index() == static_cast<unsigned>(Type::GPR); } bool isFPR() const { return m_variant.index() == static_cast<unsigned>(Type::FPR); } bool isJSValueRegs() const { return m_variant.index() == static_cast<unsigned>(Type::JSValue); } GPRReg gpr() const { ASSERT(isGPR()); return WTF::get<GPRReg>(m_variant); } FPRReg fpr() const { ASSERT(isFPR()); return WTF::get<FPRReg>(m_variant); } JSValueRegs jsValueRegs() const { ASSERT(isJSValueRegs()); return WTF::get<JSValueRegs>(m_variant); } private: Variant<GPRReg, FPRReg, JSValueRegs> m_variant; }; } #endif