Enum LabelUse 

pub enum LabelUse {
    X86JmpRel32,
    RVJal20,
    RVPCRel32,
    RVB12,
    RVPCRelHi20,
    RVPCRelLo12I,
    RVCJump,
    RVCB9,
    A64Branch14,
    A64Branch19,
    A64Branch26,
    A64Ldr19,
    A64Adr21,
}

Variants

X86JmpRel32

RVJal20

20-bit branch offset (unconditional branches). PC-rel, offset is imm << 1. Immediate is 20 signed bits. Use in Jal instructions.

RVPCRel32

The unconditional jump instructions all use PC-relative addressing to help support position independent code. The JALR instruction was defined to enable a two-instruction sequence to jump anywhere in a 32-bit absolute address range. A LUI instruction can first load rs1 with the upper 20 bits of a target address, then JALR can add in the lower bits. Similarly, AUIPC then JALR can jump anywhere in a 32-bit pc-relative address range.

RVB12

All branch instructions use the B-type instruction format. The 12-bit B-immediate encodes signed offsets in multiples of 2, and is added to the current pc to give the target address. The conditional branch range is ±4 KiB.

RVPCRelHi20

Equivalent to the R_RISCV_PCREL_HI20 relocation, Allows setting the immediate field of an auipc instruction.

RVPCRelLo12I

Similar to the R_RISCV_PCREL_LO12_I relocation but pointing to the final address, instead of the PCREL_HI20 label. Allows setting the immediate field of I Type instructions such as addi or lw.

Since we currently don’t support offsets in labels, this relocation has an implicit offset of 4.

RVCJump

11-bit PC-relative jump offset. Equivalent to the RVC_JUMP relocation

RVCB9

9-bit PC-relative branch offset.

A64Branch14

14-bit branch offset (conditional branches). PC-rel, offset is imm << 2. Immediate is 14 signed bits, in bits 18:5. Used by tbz and tbnz.

A64Branch19

19-bit branch offset (conditional branches). PC-rel, offset is imm << 2. Immediate is 19 signed bits, in bits 23:5. Used by cbz, cbnz, b.cond.

A64Branch26

26-bit branch offset (unconditional branches). PC-rel, offset is imm << 2. Immediate is 26 signed bits, in bits 25:0. Used by b, bl.

A64Ldr19

A64Adr21

Implementations

impl LabelUse

pub const fn max_pos_range(self) -> CodeOffset

Maximum PC-relative range (positive), inclusive.

pub const fn max_neg_range(self) -> CodeOffset

pub const fn patch_size(&self) -> usize

pub const fn align(&self) -> usize

pub const fn supports_veneer(&self) -> bool

pub const fn veneer_size(&self) -> usize

pub fn generate_veneer( &self, buffer: &mut [u8], veneer_offset: CodeOffset, ) -> (CodeOffset, Self)

pub fn patch( &self, buffer: &mut [u8], use_offset: CodeOffset, label_offset: CodeOffset, )

Trait Implementations

impl Clone for LabelUse

fn clone(&self) -> LabelUse

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LabelUse

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Ord for LabelUse

fn cmp(&self, other: &LabelUse) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for LabelUse

fn eq(&self, other: &LabelUse) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for LabelUse

fn partial_cmp(&self, other: &LabelUse) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for LabelUse

impl Eq for LabelUse

impl StructuralPartialEq for LabelUse