- // Address:
- //
- // Describes a simple base-offset address.
- struct Address {
- explicit Address(RegisterID base, int32_t offset = 0)
- : base(base)
- , offset(offset)
- {
- }
-
- RegisterID base;
- int32_t offset;
- };
-
- // ImplicitAddress:
- //
- // This class is used for explicit 'load' and 'store' operations
- // (as opposed to situations in which a memory operand is provided
- // to a generic operation, such as an integer arithmetic instruction).
- //
- // In the case of a load (or store) operation we want to permit
- // addresses to be implicitly constructed, e.g. the two calls:
- //
- // load32(Address(addrReg), destReg);
- // load32(addrReg, destReg);
- //
- // Are equivalent, and the explicit wrapping of the Address in the former
- // is unnecessary.
- struct ImplicitAddress {
- ImplicitAddress(RegisterID base)
- : base(base)
- , offset(0)
- {
- }
-
- ImplicitAddress(Address address)
- : base(address.base)
- , offset(address.offset)
- {
- }
-
- RegisterID base;
- int32_t offset;
- };
-
- // BaseIndex:
- //
- // Describes a complex addressing mode.
- struct BaseIndex {
- BaseIndex(RegisterID base, RegisterID index, Scale scale, int32_t offset = 0)
- : base(base)
- , index(index)
- , scale(scale)
- , offset(offset)
- {
- }
-
- RegisterID base;
- RegisterID index;
- Scale scale;
- int32_t offset;
- };
-
- // AbsoluteAddress:
- //
- // Describes an memory operand given by a pointer. For regular load & store
- // operations an unwrapped void* will be used, rather than using this.
- struct AbsoluteAddress {
- explicit AbsoluteAddress(void* ptr)
- : m_ptr(ptr)
- {
- }
-
- void* m_ptr;
- };
-
-
- class Jump;
- class PatchBuffer;
-
- // DataLabelPtr:
- //
- // A DataLabelPtr is used to refer to a location in the code containing a pointer to be
- // patched after the code has been generated.
- class DataLabelPtr {
- friend class MacroAssembler;
- friend class PatchBuffer;
-
- public:
- DataLabelPtr()
- {
- }
-
- DataLabelPtr(MacroAssembler* masm)
- : m_label(masm->m_assembler.label())
- {
- }
-
- static void patch(void* address, void* value)
- {
- X86Assembler::patchPointer(reinterpret_cast<intptr_t>(address), reinterpret_cast<intptr_t>(value));
- }
-
- private:
- X86Assembler::JmpDst m_label;
- };
-
- // DataLabel32:
- //
- // A DataLabelPtr is used to refer to a location in the code containing a pointer to be
- // patched after the code has been generated.
- class DataLabel32 {
- friend class MacroAssembler;
- friend class PatchBuffer;
-
- public:
- DataLabel32()
- {
- }
-
- DataLabel32(MacroAssembler* masm)
- : m_label(masm->m_assembler.label())
- {
- }
-
- static void patch(void* address, int32_t value)
- {
- X86Assembler::patchImmediate(reinterpret_cast<intptr_t>(address), value);
- }
-
- private:
- X86Assembler::JmpDst m_label;
- };
-
- // Label:
- //
- // A Label records a point in the generated instruction stream, typically such that
- // it may be used as a destination for a jump.
- class Label {
- friend class Jump;
- friend class MacroAssembler;
- friend class PatchBuffer;
-
- public:
- Label()
- {
- }
-
- Label(MacroAssembler* masm)
- : m_label(masm->m_assembler.label())
- {
- }
-
- // FIXME: transitionary method, while we replace JmpSrces with Jumps.
- operator X86Assembler::JmpDst()
- {
- return m_label;
- }
-
- private:
- X86Assembler::JmpDst m_label;
- };
-
-
- // Jump:
- //
- // A jump object is a reference to a jump instruction that has been planted
- // into the code buffer - it is typically used to link the jump, setting the
- // relative offset such that when executed it will jump to the desired
- // destination.
- //
- // Jump objects retain a pointer to the assembler for syntactic purposes -
- // to allow the jump object to be able to link itself, e.g.:
- //
- // Jump forwardsBranch = jne32(Imm32(0), reg1);
- // // ...
- // forwardsBranch.link();
- //
- // Jumps may also be linked to a Label.
- class Jump {
- friend class PatchBuffer;
- friend class MacroAssembler;
-
- public:
- Jump()
- {
- }
-
- // FIXME: transitionary method, while we replace JmpSrces with Jumps.
- Jump(X86Assembler::JmpSrc jmp)
- : m_jmp(jmp)
- {
- }
-
- void link(MacroAssembler* masm)
- {
- masm->m_assembler.link(m_jmp, masm->m_assembler.label());
- }
-
- void linkTo(Label label, MacroAssembler* masm)
- {
- masm->m_assembler.link(m_jmp, label.m_label);
- }
-
- // FIXME: transitionary method, while we replace JmpSrces with Jumps.
- operator X86Assembler::JmpSrc()
- {
- return m_jmp;
- }
-
- static void patch(void* address, void* destination)
- {
- X86Assembler::patchBranchOffset(reinterpret_cast<intptr_t>(address), destination);
- }
-
- private:
- X86Assembler::JmpSrc m_jmp;
- };
-
- // JumpList:
- //
- // A JumpList is a set of Jump objects.
- // All jumps in the set will be linked to the same destination.
- class JumpList {
- friend class PatchBuffer;
-
- public:
- void link(MacroAssembler* masm)
- {
- size_t size = m_jumps.size();
- for (size_t i = 0; i < size; ++i)
- m_jumps[i].link(masm);
- m_jumps.clear();
- }
-
- void linkTo(Label label, MacroAssembler* masm)
- {
- size_t size = m_jumps.size();
- for (size_t i = 0; i < size; ++i)
- m_jumps[i].linkTo(label, masm);
- m_jumps.clear();
- }
-
- void append(Jump jump)
- {
- m_jumps.append(jump);
- }
-
- void append(JumpList& other)
- {
- m_jumps.append(other.m_jumps.begin(), other.m_jumps.size());
- }
-
- bool empty()
- {
- return !m_jumps.size();
- }
-
- private:
- Vector<Jump, 16> m_jumps;
- };
-
-
- // PatchBuffer:
- //
- // This class assists in linking code generated by the macro assembler, once code generation
- // has been completed, and the code has been copied to is final location in memory. At this
- // time pointers to labels within the code may be resolved, and relative offsets to external
- // addresses may be fixed.
- //
- // Specifically:
- // * Jump objects may be linked to external targets,
- // * The address of Jump objects may taken, such that it can later be relinked.
- // * The return address of a Jump object representing a call may be acquired.
- // * The address of a Label pointing into the code may be resolved.
- // * The value referenced by a DataLabel may be fixed.
- //
- // FIXME: distinguish between Calls & Jumps (make a specific call to obtain the return
- // address of calls, as opposed to a point that can be used to later relink a Jump -
- // possibly wrap the later up in an object that can do just that).
- class PatchBuffer {
- public:
- PatchBuffer(void* code)
- : m_code(code)
- {
- }
-
- void link(Jump jump, void* target)
- {
- X86Assembler::link(m_code, jump.m_jmp, target);
- }
-
- void link(JumpList list, void* target)
- {
- for (unsigned i = 0; i < list.m_jumps.size(); ++i)
- X86Assembler::link(m_code, list.m_jumps[i], target);
- }
-
- void* addressOf(Jump jump)
- {
- return X86Assembler::getRelocatedAddress(m_code, jump.m_jmp);
- }
-
- void* addressOf(Label label)
- {
- return X86Assembler::getRelocatedAddress(m_code, label.m_label);
- }
-
- void* addressOf(DataLabelPtr label)
- {
- return X86Assembler::getRelocatedAddress(m_code, label.m_label);
- }
-
- void* addressOf(DataLabel32 label)
- {
- return X86Assembler::getRelocatedAddress(m_code, label.m_label);
- }
-
- void setPtr(DataLabelPtr label, void* value)
- {
- X86Assembler::patchAddress(m_code, label.m_label, value);
- }
-
- private:
- void* m_code;
- };
-
-
- // ImmPtr:
- //
- // A pointer sized immediate operand to an instruction - this is wrapped
- // in a class requiring explicit construction in order to differentiate
- // from pointers used as absolute addresses to memory operations
- struct ImmPtr {
- explicit ImmPtr(void* value)
- : m_value(value)
- {
- }
-
- intptr_t asIntptr()
- {
- return reinterpret_cast<intptr_t>(m_value);
projects / apple / javascriptcore.git / blobdiff