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/*
* Copyright (C) 2018-2019 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 "GetPutInfo.h"
#include "Interpreter.h"
#include "Label.h"
#include "OpcodeSize.h"
#include "ProfileTypeBytecodeFlag.h"
#include "PutByIdFlags.h"
#include "ResultType.h"
#include "SpecialPointer.h"
#include "SymbolTableOrScopeDepth.h"
#include "VirtualRegister.h"
#include <type_traits>
namespace JSC {
enum FitsAssertion {
Assert,
NoAssert
};
// Fits template
template<typename, OpcodeSize, typename = std::true_type>
struct Fits;
// Implicit conversion for types of the same size
template<typename T, OpcodeSize size>
struct Fits<T, size, std::enable_if_t<sizeof(T) == size, std::true_type>> {
static bool check(T) { return true; }
static typename TypeBySize<size>::type convert(T t) { return bitwise_cast<typename TypeBySize<size>::type>(t); }
template<class T1 = T, OpcodeSize size1 = size, typename = std::enable_if_t<!std::is_same<T1, typename TypeBySize<size1>::type>::value, std::true_type>>
static T1 convert(typename TypeBySize<size1>::type t) { return bitwise_cast<T1>(t); }
};
template<typename T, OpcodeSize size>
struct Fits<T, size, std::enable_if_t<sizeof(T) < size, std::true_type>> {
static bool check(T) { return true; }
static typename TypeBySize<size>::type convert(T t) { return static_cast<typename TypeBySize<size>::type>(t); }
template<class T1 = T, OpcodeSize size1 = size, typename = std::enable_if_t<!std::is_same<T1, typename TypeBySize<size1>::type>::value, std::true_type>>
static T1 convert(typename TypeBySize<size1>::type t) { return static_cast<T1>(t); }
};
template<>
struct Fits<uint32_t, OpcodeSize::Narrow> {
static bool check(unsigned u) { return u <= UINT8_MAX; }
static uint8_t convert(unsigned u)
{
ASSERT(check(u));
return static_cast<uint8_t>(u);
}
static unsigned convert(uint8_t u)
{
return u;
}
};
template<>
struct Fits<int, OpcodeSize::Narrow> {
static bool check(int i)
{
return i >= INT8_MIN && i <= INT8_MAX;
}
static uint8_t convert(int i)
{
ASSERT(check(i));
return static_cast<uint8_t>(i);
}
static int convert(uint8_t i)
{
return static_cast<int8_t>(i);
}
};
template<>
struct Fits<VirtualRegister, OpcodeSize::Narrow> {
// -128..-1 local variables
// 0..15 arguments
// 16..127 constants
static constexpr int s_firstConstantIndex = 16;
static bool check(VirtualRegister r)
{
if (r.isConstant())
return (s_firstConstantIndex + r.toConstantIndex()) <= INT8_MAX;
return r.offset() >= INT8_MIN && r.offset() < s_firstConstantIndex;
}
static uint8_t convert(VirtualRegister r)
{
ASSERT(check(r));
if (r.isConstant())
return static_cast<int8_t>(s_firstConstantIndex + r.toConstantIndex());
return static_cast<int8_t>(r.offset());
}
static VirtualRegister convert(uint8_t u)
{
int i = static_cast<int>(static_cast<int8_t>(u));
if (i >= s_firstConstantIndex)
return VirtualRegister { (i - s_firstConstantIndex) + FirstConstantRegisterIndex };
return VirtualRegister { i };
}
};
template<>
struct Fits<SymbolTableOrScopeDepth, OpcodeSize::Narrow> {
static bool check(SymbolTableOrScopeDepth u)
{
return u.raw() <= UINT8_MAX;
}
static uint8_t convert(SymbolTableOrScopeDepth u)
{
ASSERT(check(u));
return static_cast<uint8_t>(u.raw());
}
static SymbolTableOrScopeDepth convert(uint8_t u)
{
return SymbolTableOrScopeDepth::raw(u);
}
};
template<>
struct Fits<Special::Pointer, OpcodeSize::Narrow> : Fits<int, OpcodeSize::Narrow> {
using Base = Fits<int, OpcodeSize::Narrow>;
static bool check(Special::Pointer sp) { return Base::check(static_cast<int>(sp)); }
static uint8_t convert(Special::Pointer sp)
{
return Base::convert(static_cast<int>(sp));
}
static Special::Pointer convert(uint8_t sp)
{
return static_cast<Special::Pointer>(Base::convert(sp));
}
};
template<>
struct Fits<GetPutInfo, OpcodeSize::Narrow> {
// 13 Resolve Types
// 3 Initialization Modes
// 2 Resolve Modes
//
// Try to encode encode as
//
// initialization mode
// v
// free bit-> 0|0000|00|0
// ^ ^
// resolve type resolve mode
static constexpr int s_resolveTypeMax = 1 << 4;
static constexpr int s_initializationModeMax = 1 << 2;
static constexpr int s_resolveModeMax = 1 << 1;
static constexpr int s_resolveTypeBits = (s_resolveTypeMax - 1) << 3;
static constexpr int s_initializationModeBits = (s_initializationModeMax - 1) << 1;
static constexpr int s_resolveModeBits = (s_resolveModeMax - 1);
static_assert(!(s_resolveTypeBits & s_initializationModeBits & s_resolveModeBits), "There should be no intersection between ResolveMode, ResolveType and InitializationMode");
static bool check(GetPutInfo gpi)
{
auto resolveType = static_cast<int>(gpi.resolveType());
auto initializationMode = static_cast<int>(gpi.initializationMode());
auto resolveMode = static_cast<int>(gpi.resolveMode());
return resolveType < s_resolveTypeMax && initializationMode < s_initializationModeMax && resolveMode < s_resolveModeMax;
}
static uint8_t convert(GetPutInfo gpi)
{
ASSERT(check(gpi));
auto resolveType = static_cast<uint8_t>(gpi.resolveType());
auto initializationMode = static_cast<uint8_t>(gpi.initializationMode());
auto resolveMode = static_cast<uint8_t>(gpi.resolveMode());
return (resolveType << 3) | (initializationMode << 1) | resolveMode;
}
static GetPutInfo convert(uint8_t gpi)
{
auto resolveType = static_cast<ResolveType>((gpi & s_resolveTypeBits) >> 3);
auto initializationMode = static_cast<InitializationMode>((gpi & s_initializationModeBits) >> 1);
auto resolveMode = static_cast<ResolveMode>(gpi & s_resolveModeBits);
return GetPutInfo(resolveMode, resolveType, initializationMode);
}
};
template<>
struct Fits<DebugHookType, OpcodeSize::Narrow> : Fits<int, OpcodeSize::Narrow> {
using Base = Fits<int, OpcodeSize::Narrow>;
static bool check(DebugHookType dht) { return Base::check(static_cast<int>(dht)); }
static uint8_t convert(DebugHookType dht)
{
return Base::convert(static_cast<int>(dht));
}
static DebugHookType convert(uint8_t dht)
{
return static_cast<DebugHookType>(Base::convert(dht));
}
};
template<>
struct Fits<ProfileTypeBytecodeFlag, OpcodeSize::Narrow> : Fits<int, OpcodeSize::Narrow> {
using Base = Fits<int, OpcodeSize::Narrow>;
static bool check(ProfileTypeBytecodeFlag ptbf) { return Base::check(static_cast<int>(ptbf)); }
static uint8_t convert(ProfileTypeBytecodeFlag ptbf)
{
return Base::convert(static_cast<int>(ptbf));
}
static ProfileTypeBytecodeFlag convert(uint8_t ptbf)
{
return static_cast<ProfileTypeBytecodeFlag>(Base::convert(ptbf));
}
};
template<>
struct Fits<ResolveType, OpcodeSize::Narrow> : Fits<int, OpcodeSize::Narrow> {
using Base = Fits<int, OpcodeSize::Narrow>;
static bool check(ResolveType rt) { return Base::check(static_cast<int>(rt)); }
static uint8_t convert(ResolveType rt)
{
return Base::convert(static_cast<int>(rt));
}
static ResolveType convert(uint8_t rt)
{
return static_cast<ResolveType>(Base::convert(rt));
}
};
template<>
struct Fits<OperandTypes, OpcodeSize::Narrow> {
// a pair of (ResultType::Type, ResultType::Type) - try to fit each type into 4 bits
// additionally, encode unknown types as 0 rather than the | of all types
static constexpr int s_maxType = 0x10;
static bool check(OperandTypes types)
{
auto first = types.first().bits();
auto second = types.second().bits();
if (first == ResultType::unknownType().bits())
first = 0;
if (second == ResultType::unknownType().bits())
second = 0;
return first < s_maxType && second < s_maxType;
}
static uint8_t convert(OperandTypes types)
{
ASSERT(check(types));
auto first = types.first().bits();
auto second = types.second().bits();
if (first == ResultType::unknownType().bits())
first = 0;
if (second == ResultType::unknownType().bits())
second = 0;
return (first << 4) | second;
}
static OperandTypes convert(uint8_t types)
{
auto first = (types & (0xf << 4)) >> 4;
auto second = (types & 0xf);
if (!first)
first = ResultType::unknownType().bits();
if (!second)
second = ResultType::unknownType().bits();
return OperandTypes(ResultType(first), ResultType(second));
}
};
template<>
struct Fits<PutByIdFlags, OpcodeSize::Narrow> : Fits<int, OpcodeSize::Narrow> {
// only ever encoded in the bytecode stream as 0 or 1, so the trivial encoding should be good enough
using Base = Fits<int, OpcodeSize::Narrow>;
static bool check(PutByIdFlags flags) { return Base::check(static_cast<int>(flags)); }
static uint8_t convert(PutByIdFlags flags)
{
return Base::convert(static_cast<int>(flags));
}
static PutByIdFlags convert(uint8_t flags)
{
return static_cast<PutByIdFlags>(Base::convert(flags));
}
};
template<OpcodeSize size>
struct Fits<BoundLabel, size> : Fits<int, size> {
// This is a bit hacky: we need to delay computing jump targets, since we
// might have to emit `nop`s to align the instructions stream. Additionally,
// we have to compute the target before we start writing to the instruction
// stream, since the offset is computed from the start of the bytecode. We
// achieve this by computing the target when we `check` and saving it, then
// later we use the saved target when we call convert.
using Base = Fits<int, size>;
static bool check(BoundLabel& label)
{
return Base::check(label.saveTarget());
}
static typename TypeBySize<size>::type convert(BoundLabel& label)
{
return Base::convert(label.commitTarget());
}
static BoundLabel convert(typename TypeBySize<size>::type target)
{
return BoundLabel(Base::convert(target));
}
};
} // namespace JSC