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Diffstat (limited to 'Source/JavaScriptCore/b3/B3CheckSpecial.h')
| -rw-r--r-- | Source/JavaScriptCore/b3/B3CheckSpecial.h | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/b3/B3CheckSpecial.h b/Source/JavaScriptCore/b3/B3CheckSpecial.h new file mode 100644 index 000000000..7a37934a8 --- /dev/null +++ b/Source/JavaScriptCore/b3/B3CheckSpecial.h @@ -0,0 +1,171 @@ +/* + * Copyright (C) 2015 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 B3CheckSpecial_h +#define B3CheckSpecial_h + +#if ENABLE(B3_JIT) + +#include "AirArg.h" +#include "AirOpcode.h" +#include "B3StackmapSpecial.h" +#include <wtf/HashMap.h> + +namespace JSC { namespace B3 { + +namespace Air { +struct Inst; +} + +// We want to lower Check instructions to a branch, but then we want to route that branch to our +// out-of-line code instead of doing anything else. For this reason, a CheckSpecial will remember +// which branch opcode we have selected along with the number of args in the overload we want. It +// will create an Inst with that opcode plus the appropriate args from the owning Inst whenever you +// call any of the callbacks. +// +// Note that for CheckAdd, CheckSub, and CheckMul we expect that the B3 arguments are the reverse +// of the Air arguments (Add(a, b) => Add32 b, a). Except: +// - CheckSub(0, x), which turns into BranchNeg32 x. +// - CheckMul(a, b), which turns into Mul32 b, a but we pass Any for a's ValueRep. + +class CheckSpecial : public StackmapSpecial { +public: + // Support for hash consing these things. + class Key { + public: + Key() + : m_opcode(Air::Nop) + , m_stackmapRole(SameAsRep) + , m_numArgs(0) + { + } + + Key(Air::Opcode opcode, unsigned numArgs, RoleMode stackmapRole = SameAsRep) + : m_opcode(opcode) + , m_stackmapRole(stackmapRole) + , m_numArgs(numArgs) + { + } + + explicit Key(const Air::Inst&); + + bool operator==(const Key& other) const + { + return m_opcode == other.m_opcode + && m_numArgs == other.m_numArgs + && m_stackmapRole == other.m_stackmapRole; + } + + bool operator!=(const Key& other) const + { + return !(*this == other); + } + + explicit operator bool() const { return *this != Key(); } + + Air::Opcode opcode() const { return m_opcode; } + unsigned numArgs() const { return m_numArgs; } + RoleMode stackmapRole() const { return m_stackmapRole; } + + void dump(PrintStream& out) const; + + Key(WTF::HashTableDeletedValueType) + : m_opcode(Air::Nop) + , m_stackmapRole(SameAsRep) + , m_numArgs(1) + { + } + + bool isHashTableDeletedValue() const + { + return *this == Key(WTF::HashTableDeletedValue); + } + + unsigned hash() const + { + // Seriously, we don't need to be smart here. It just doesn't matter. + return m_opcode + m_numArgs + m_stackmapRole; + } + + private: + Air::Opcode m_opcode; + RoleMode m_stackmapRole; + unsigned m_numArgs; + }; + + CheckSpecial(Air::Opcode, unsigned numArgs, RoleMode stackmapRole = SameAsRep); + CheckSpecial(const Key&); + ~CheckSpecial(); + +protected: + // Constructs and returns the Inst representing the branch that this will use. + Air::Inst hiddenBranch(const Air::Inst&) const; + + void forEachArg(Air::Inst&, const ScopedLambda<Air::Inst::EachArgCallback>&) override; + bool isValid(Air::Inst&) override; + bool admitsStack(Air::Inst&, unsigned argIndex) override; + Optional<unsigned> shouldTryAliasingDef(Air::Inst&) override; + + // NOTE: the generate method will generate the hidden branch and then register a LatePath that + // generates the stackmap. Super crazy dude! + + CCallHelpers::Jump generate(Air::Inst&, CCallHelpers&, Air::GenerationContext&) override; + + void dumpImpl(PrintStream&) const override; + void deepDumpImpl(PrintStream&) const override; + +private: + Air::Opcode m_checkOpcode; + RoleMode m_stackmapRole; + unsigned m_numCheckArgs; +}; + +struct CheckSpecialKeyHash { + static unsigned hash(const CheckSpecial::Key& key) { return key.hash(); } + static bool equal(const CheckSpecial::Key& a, const CheckSpecial::Key& b) { return a == b; } + static const bool safeToCompareToEmptyOrDeleted = true; +}; + +} } // namespace JSC::B3 + +namespace WTF { + +template<typename T> struct DefaultHash; +template<> struct DefaultHash<JSC::B3::CheckSpecial::Key> { + typedef JSC::B3::CheckSpecialKeyHash Hash; +}; + +template<typename T> struct HashTraits; +template<> struct HashTraits<JSC::B3::CheckSpecial::Key> : SimpleClassHashTraits<JSC::B3::CheckSpecial::Key> { + // I don't want to think about this very hard, it's not worth it. I'm a be conservative. + static const bool emptyValueIsZero = false; +}; + +} // namespace WTF + +#endif // ENABLE(B3_JIT) + +#endif // B3CheckSpecial_h + |