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// Copyright 2018 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_TURBO_ASSEMBLER_H_
#define V8_TURBO_ASSEMBLER_H_
#include "src/assembler-arch.h"
#include "src/base/template-utils.h"
#include "src/heap/heap.h"
namespace v8 {
namespace internal {
// Common base class for platform-specific TurboAssemblers containing
// platform-independent bits.
class V8_EXPORT_PRIVATE TurboAssemblerBase : public Assembler {
public:
Isolate* isolate() const {
DCHECK(!options().v8_agnostic_code);
return isolate_;
}
Handle<HeapObject> CodeObject() const {
DCHECK(!code_object_.is_null());
return code_object_;
}
bool root_array_available() const { return root_array_available_; }
void set_root_array_available(bool v) { root_array_available_ = v; }
bool trap_on_abort() const { return trap_on_abort_; }
bool should_abort_hard() const { return hard_abort_; }
void set_abort_hard(bool v) { hard_abort_ = v; }
void set_builtin_index(int i) { maybe_builtin_index_ = i; }
void set_has_frame(bool v) { has_frame_ = v; }
bool has_frame() const { return has_frame_; }
// Loads the given constant or external reference without embedding its direct
// pointer. The produced code is isolate-independent.
void IndirectLoadConstant(Register destination, Handle<HeapObject> object);
void IndirectLoadExternalReference(Register destination,
ExternalReference reference);
virtual void LoadFromConstantsTable(Register destination,
int constant_index) = 0;
virtual void LoadRootRegisterOffset(Register destination,
intptr_t offset) = 0;
virtual void LoadRootRelative(Register destination, int32_t offset) = 0;
virtual void LoadRoot(Register destination, RootIndex index) = 0;
static int32_t RootRegisterOffset(RootIndex root_index);
static int32_t RootRegisterOffsetForExternalReferenceIndex(
int reference_index);
static int32_t RootRegisterOffsetForBuiltinIndex(int builtin_index);
static intptr_t RootRegisterOffsetForExternalReference(
Isolate* isolate, const ExternalReference& reference);
// An address is addressable through kRootRegister if it is located within
// isolate->root_register_addressable_region().
static bool IsAddressableThroughRootRegister(
Isolate* isolate, const ExternalReference& reference);
protected:
TurboAssemblerBase(const AssemblerOptions& options, void* buffer,
int buffer_size)
: TurboAssemblerBase(nullptr, options.EnableV8AgnosticCode(), buffer,
buffer_size, CodeObjectRequired::kNo) {}
TurboAssemblerBase(Isolate* isolate, const AssemblerOptions& options,
void* buffer, int buffer_size,
CodeObjectRequired create_code_object);
void RecordCommentForOffHeapTrampoline(int builtin_index);
Isolate* const isolate_ = nullptr;
// This handle will be patched with the code object on installation.
Handle<HeapObject> code_object_;
// Whether kRootRegister has been initialized.
bool root_array_available_ = true;
// Immediately trap instead of calling {Abort} when debug code fails.
bool trap_on_abort_ = FLAG_trap_on_abort;
// Emit a C call to abort instead of a runtime call.
bool hard_abort_ = false;
// May be set while generating builtins.
int maybe_builtin_index_ = Builtins::kNoBuiltinId;
bool has_frame_ = false;
DISALLOW_IMPLICIT_CONSTRUCTORS(TurboAssemblerBase);
};
// Avoids emitting calls to the {Builtins::kAbort} builtin when emitting debug
// code during the lifetime of this scope object. For disabling debug code
// entirely use the {DontEmitDebugCodeScope} instead.
class HardAbortScope {
public:
explicit HardAbortScope(TurboAssemblerBase* assembler)
: assembler_(assembler), old_value_(assembler->should_abort_hard()) {
assembler_->set_abort_hard(true);
}
~HardAbortScope() { assembler_->set_abort_hard(old_value_); }
private:
TurboAssemblerBase* assembler_;
bool old_value_;
};
// Helper stubs can be called in different ways depending on where the target
// code is located and how the call sequence is expected to look like:
// - JavaScript: Call on-heap {Code} object via {RelocInfo::CODE_TARGET}.
// - WebAssembly: Call native {WasmCode} stub via {RelocInfo::WASM_STUB_CALL}.
enum class StubCallMode { kCallOnHeapBuiltin, kCallWasmRuntimeStub };
#ifdef DEBUG
template <typename RegType, typename... RegTypes,
// All arguments must be either Register or DoubleRegister.
typename = typename std::enable_if<
base::is_same<Register, RegType, RegTypes...>::value ||
base::is_same<DoubleRegister, RegType, RegTypes...>::value>::type>
inline bool AreAliased(RegType first_reg, RegTypes... regs) {
int num_different_regs = NumRegs(RegType::ListOf(first_reg, regs...));
int num_given_regs = sizeof...(regs) + 1;
return num_different_regs < num_given_regs;
}
#endif
} // namespace internal
} // namespace v8
#endif // V8_TURBO_ASSEMBLER_H_
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