| /* |
| * Copyright (C) 2016 Apple Inc. All rights reserved. |
| * |
| * 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 "CPU.h" |
| #include <wtf/StdLibExtras.h> |
| |
| namespace JSC { |
| |
| #if USE(JSVALUE64) |
| // According to C++ rules, a type used for the return signature of function with C linkage (i.e. |
| // 'extern "C"') needs to be POD; hence putting any constructors into it could cause either compiler |
| // warnings, or worse, a change in the ABI used to return these types. |
| struct SlowPathReturnType { |
| CPURegister a; |
| CPURegister b; |
| }; |
| static_assert(sizeof(SlowPathReturnType) >= sizeof(void*) * 2, "SlowPathReturnType should fit in two machine registers"); |
| |
| inline SlowPathReturnType encodeResult(const void* a, const void* b) |
| { |
| SlowPathReturnType result; |
| result.a = reinterpret_cast<CPURegister>(a); |
| result.b = reinterpret_cast<CPURegister>(b); |
| return result; |
| } |
| |
| inline void decodeResult(SlowPathReturnType result, const void*& a, const void*& b) |
| { |
| a = reinterpret_cast<void*>(result.a); |
| b = reinterpret_cast<void*>(result.b); |
| } |
| |
| #else // USE(JSVALUE32_64) |
| typedef int64_t SlowPathReturnType; |
| |
| typedef union { |
| struct { |
| const void* a; |
| const void* b; |
| } pair; |
| int64_t i; |
| } SlowPathReturnTypeEncoding; |
| |
| inline SlowPathReturnType encodeResult(const void* a, const void* b) |
| { |
| SlowPathReturnTypeEncoding u; |
| u.pair.a = a; |
| u.pair.b = b; |
| return u.i; |
| } |
| |
| inline void decodeResult(SlowPathReturnType result, const void*& a, const void*& b) |
| { |
| SlowPathReturnTypeEncoding u; |
| u.i = result; |
| a = u.pair.a; |
| b = u.pair.b; |
| } |
| #endif // USE(JSVALUE32_64) |
| |
| } // namespace JSC |