asmjit::VirtReg Class Reference

Virtual register data, managed by BaseCompiler.

Public Members

Members

OperandSignature _signature {}

uint32_t _id = 0

uint32_t _virtSize = 0

uint8_t _alignment = 0

TypeId _typeId = TypeId::kVoid

uint8_t _weight = 1

uint8_t _isFixed : 1

uint8_t _isStack : 1

uint8_t _hasStackSlot : 1

uint8_t _reservedBits : 5

int32_t _stackOffset = 0

uint32_t _reservedU32 = 0

ZoneString<16> _name {}

RAWorkReg* _workReg = nullptr

Member Functions

VirtReg(const VirtReg& other) = delete

VirtReg& operator=(const VirtReg& other) = delete

Construction & Destruction

VirtReg(OperandSignature signature, uint32_t id, uint32_t virtSize, uint32_t alignment, TypeId typeId) noexcept

Accessors

uint32_t id() const noexcept

const char* name() const noexcept

uint32_t nameSize() const noexcept

OperandSignature signature() const noexcept

RegType type() const noexcept

RegGroup group() const noexcept

uint32_t regSize() const noexcept

uint32_t virtSize() const noexcept

uint32_t alignment() const noexcept

TypeId typeId() const noexcept

uint32_t weight() const noexcept

void setWeight(uint32_t weight) noexcept

bool isFixed() const noexcept

bool isStack() const noexcept

bool hasStackSlot() const noexcept

void assignStackSlot(int32_t stackOffset) noexcept

int32_t stackOffset() const noexcept

bool hasWorkReg() const noexcept

RAWorkReg* workReg() const noexcept

void setWorkReg(RAWorkReg* workReg) noexcept

void resetWorkReg() noexcept

Member Function Documentation

uint32_t VirtReg::id() constnoexcept

Returns the virtual register id.

const char* VirtReg::name() constnoexcept

Returns the virtual register name.

uint32_t VirtReg::nameSize() constnoexcept

Returns the size of the virtual register name.

OperandSignature VirtReg::signature() constnoexcept

Returns a register signature of this virtual register.

RegType VirtReg::type() constnoexcept

Returns a virtual register type (maps to the physical register type as well).

RegGroup VirtReg::group() constnoexcept

Returns a virtual register group (maps to the physical register group as well).

uint32_t VirtReg::regSize() constnoexcept

Returns a real size of the register this virtual register maps to.

For example if this is a 128-bit SIMD register used for a scalar single precision floating point value then its virtSize would be 4, however, the regSize would still say 16 (128-bits), because it's the smallest size of that register type.

uint32_t VirtReg::virtSize() constnoexcept

Returns the virtual register size.

The virtual register size describes how many bytes the virtual register needs to store its content. It can be smaller than the physical register size, see regSize().

uint32_t VirtReg::alignment() constnoexcept

Returns the virtual register alignment.

TypeId VirtReg::typeId() constnoexcept

Returns the virtual register type id.

uint32_t VirtReg::weight() constnoexcept

Returns the virtual register weight - the register allocator can use it as explicit hint for alloc/spill decisions.

void VirtReg::setWeight(uint32_t weight)noexcept

Sets the virtual register weight (0 to 255) - the register allocator can use it as explicit hint for alloc/spill decisions and initial bin-packing.

bool VirtReg::isFixed() constnoexcept

Returns whether the virtual register is always allocated to a fixed physical register (and never reallocated).

Note

This is only used for special purposes and it's mostly internal.

bool VirtReg::isStack() constnoexcept

Tests whether the virtual register is in fact a stack that only uses the virtual register id.

Note

It's an error if a stack is accessed as a register.

bool VirtReg::hasStackSlot() constnoexcept

Tests whether this virtual register (or stack) has assigned a stack offset.

If this is a virtual register that was never allocated on stack, it would return false, otherwise if it's a virtual register that was spilled or explicitly allocated stack, the return value would be true.

void VirtReg::assignStackSlot(int32_t stackOffset)noexcept

Assigns a stack offset of this virtual register to stackOffset and sets _hasStackSlot to true.

int32_t VirtReg::stackOffset() constnoexcept

Returns a stack offset associated with a virtual register or explicit stack allocation.

Note

Always verify that the stack offset has been assigned by calling hasStackSlot(). The return value will be zero when the stack offset was not assigned.

bool VirtReg::hasWorkReg() constnoexcept

Tests whether the virtual register has an associated RAWorkReg at the moment.

RAWorkReg* VirtReg::workReg() constnoexcept

Returns an associated RAWorkReg with this virtual register (only valid during register allocation).

void VirtReg::setWorkReg(RAWorkReg* workReg)noexcept

Associates a RAWorkReg with this virtual register (used by register allocator).

void VirtReg::resetWorkReg()noexcept

Reset the RAWorkReg association (used by register allocator).

Member Data Documentation

OperandSignature VirtReg::_signature {}

Virtual register signature.

uint32_t VirtReg::_id = 0

Virtual register id.

uint32_t VirtReg::_virtSize = 0

Virtual register size (can be smaller than _signature._size).

uint8_t VirtReg::_alignment = 0

Virtual register alignment (for spilling).

TypeId VirtReg::_typeId = TypeId::kVoid

Type-id.

uint8_t VirtReg::_weight = 1

Virtual register weight for alloc/spill decisions.

uint8_t VirtReg::_isFixed

True if this is a fixed register, never reallocated.

uint8_t VirtReg::_isStack

True if the virtual register is only used as a stack (never accessed as register).

uint8_t VirtReg::_hasStackSlot

True if this virtual register has assigned stack offset (can be only valid after register allocation pass).

int32_t VirtReg::_stackOffset = 0

Stack offset assigned by the register allocator relative to stack pointer (can be negative as well).

uint32_t VirtReg::_reservedU32 = 0

Reserved for future use (padding).

ZoneString<16>VirtReg::_name {}

Virtual register name (user provided or automatically generated).

RAWorkReg* VirtReg::_workReg = nullptr

Reference to RAWorkReg, used during register allocation.