Struct RiscVFrame 

pub struct RiscVFrame;

Implementations

impl RiscVFrame

pub fn generate_prologue<W: Write>( writer: &mut W, stack_size: usize, callee_saved_registers: &[&str], target: RiscVTarget, ) -> Result<(), Error>

Generate function prologue

pub fn generate_epilogue<W: Write>( writer: &mut W, stack_size: usize, callee_saved_registers: &[&str], target: RiscVTarget, ) -> Result<(), Error>

Generate function epilogue

pub fn generate_tail_epilogue<W: Write>( writer: &mut W, stack_size: usize, callee_saved_registers: &[&str], target_sym: &str, target: RiscVTarget, ) -> Result<(), Error>

Like Self::generate_epilogue, but jump to target_sym instead of ret (tail call).

pub fn adjust_sp<W: Write>(writer: &mut W, delta: i64) -> Result<(), Error>

Move sp by delta bytes. Deltas outside the 12-bit range go through t0, which the prologue, epilogue and call sequences do not hold a value in.

pub fn fp_load<W: Write>( writer: &mut W, mnemonic: &str, reg: &str, offset: i32, scratch: &str, ) -> Result<(), Error>

Emit {mnemonic} {reg}, {offset}(fp), building the address in scratch when the offset does not fit the 12-bit immediate. reg is overwritten by a load, so it may serve as the scratch for one.

pub fn fp_store<W: Write>( writer: &mut W, mnemonic: &str, reg: &str, offset: i32, scratch: &str, ) -> Result<(), Error>

Store reg at {offset}(fp). A store must not clobber reg, so when the offset is out of range and reg is t0, fp itself is walked to the slot and back.

pub fn fp_address<W: Write>( writer: &mut W, dst: &str, offset: i32, ) -> Result<(), Error>

Materialise fp + offset into dst.

pub fn load_imm<W: Write>( writer: &mut W, reg: &str, value: i64, ) -> Result<(), Error>

Load value into reg. ras only encodes li for 12-bit immediates, so larger values are built from slli and addi steps.

pub fn calculate_stack_offset(slot_index: usize, target: RiscVTarget) -> i32

Offset of a local slot from fp.

The prologue leaves fp at the caller’s sp, with ra at fp-8 and the caller’s fp at fp-16. Locals start below that pair. This used to return fp-8 for slot 0 and fp-16 for slot 1, so the first local overwrote the return address and the second overwrote the saved frame pointer.