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/*
* 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.
*/
#ifndef AirKind_h
#define AirKind_h
#if ENABLE(B3_JIT)
#include "AirOpcode.h"
#include <wtf/PrintStream.h>
namespace JSC { namespace B3 { namespace Air {
// Air opcodes are always carried around with some flags. These flags are understood as having no
// meaning if they are set for an opcode to which they do not apply. This makes sense, since Air
// is a complex instruction set and most of these flags can apply to basically any opcode. In
// fact, it's recommended to only represent something as a flag if you believe that it is largely
// opcode-agnostic.
struct Kind {
Kind(Opcode opcode)
: opcode(opcode)
, traps(false)
{
}
Kind()
: Kind(Nop)
{
}
bool operator==(const Kind& other) const
{
return opcode == other.opcode
&& traps == other.traps;
}
bool operator!=(const Kind& other) const
{
return !(*this == other);
}
unsigned hash() const
{
return static_cast<unsigned>(opcode) + (static_cast<unsigned>(traps) << 16);
}
explicit operator bool() const
{
return *this != Kind();
}
void dump(PrintStream&) const;
Opcode opcode;
// This is an opcode-agnostic flag that indicates that we expect that this instruction will
// trap. This causes the compiler to assume that this side-exits and therefore has non-control
// non-arg effects. This also causes the compiler to tell you about all of these instructions.
// Note that this is just one of several ways of supporting trapping in Air, and it's the less
// precise variant because it's origin-based. This means that if an instruction was fused out
// of B3 values that had different origins, then the origin at which you'll appear to trap
// will be somewhat random. The upside of this approach is that it imposes by far the least
// overhead on the compiler.
// FIXME: Make this completely work.
// https://bugs.webkit.org/show_bug.cgi?id=162689
bool traps : 1;
};
} } } // namespace JSC::B3::Air
#endif // ENABLE(B3_JIT)
#endif // AirKind_h
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