/* * Copyright (C) 2015-2016 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 #if ENABLE(B3_JIT) namespace JSC { namespace B3 { namespace Air { enum class StackSlotKind : uint8_t { // A locked stack slot is an area of stack requested by the client. It cannot be killed. The // client can get its FP offset and write to it from stack walking code, so we must assume // that reads and writes to a locked stack slot can be clobbered the same way as reads and // writes to any memory location. Locked, // A spill slot. These have fundamentally different behavior than a typical memory location. // They are lowered to from temporaries. This means for example that a 32-bit ZDef store to a // 8 byte stack slot will zero the top 4 bytes, even though a 32-bit ZDef store to any other // kind of memory location would do no such thing. UseAddr on a spill slot is not allowed, so // they never escape. Spill // FIXME: We should add a third mode, which means that the stack slot will be read asynchronously // as with Locked, but never written to asynchronously. Then, Air could optimize spilling and // filling by tracking whether the value had been stored to a read-only locked slot. If it had, // then we can refill from that slot. // https://bugs.webkit.org/show_bug.cgi?id=150587 }; } } } // namespace JSC::B3::Air namespace WTF { class PrintStream; void printInternal(PrintStream&, JSC::B3::Air::StackSlotKind); } // namespace WTF #endif // ENABLE(B3_JIT)