Struct cranelift_codegen::ir::layout::Layout

pub struct Layout { /* fields omitted */ }

The Layout struct determines the layout of EBBs and instructions in a function. It does not contain definitions of instructions or EBBs, but depends on Inst and Ebb entity references being defined elsewhere.

This data structure determines:

• The order of EBBs in the function.
• Which EBB contains a given instruction.
• The order of instructions with an EBB.

While data dependencies are not recorded, instruction ordering does affect control dependencies, so part of the semantics of the program are determined by the layout.

Methods

impl Layout

pub fn new() -> Self

Create a new empty Layout.

pub fn clear(&mut self)

Clear the layout.

impl Layout

Methods for laying out EBBs.

An unknown EBB starts out as not inserted in the EBB layout. The layout is a linear order of inserted EBBs. Once an EBB has been inserted in the layout, instructions can be added. An EBB can only be removed from the layout when it is empty.

Since every EBB must end with a terminator instruction which cannot fall through, the layout of EBBs do not affect the semantics of the program.

pub fn is_ebb_inserted(&self, ebb: Ebb) -> bool

Is ebb currently part of the layout?

pub fn append_ebb(&mut self, ebb: Ebb)

Insert ebb as the last EBB in the layout.

pub fn insert_ebb(&mut self, ebb: Ebb, before: Ebb)

Insert ebb in the layout before the existing EBB before.

pub fn insert_ebb_after(&mut self, ebb: Ebb, after: Ebb)

Insert ebb in the layout after the existing EBB after.

pub fn remove_ebb(&mut self, ebb: Ebb)

Remove ebb from the layout.

Important traits for Ebbs<'f>

impl<'f> Iterator for Ebbs<'f> type Item = Ebb;

pub fn ebbs(&self) -> Ebbs

Return an iterator over all EBBs in layout order.

pub fn entry_block(&self) -> Option<Ebb>

Get the function's entry block. This is simply the first EBB in the layout order.

pub fn last_ebb(&self) -> Option<Ebb>

Get the last EBB in the layout.

pub fn prev_ebb(&self, ebb: Ebb) -> Option<Ebb>

Get the block preceding ebb in the layout order.

pub fn next_ebb(&self, ebb: Ebb) -> Option<Ebb>

Get the block following ebb in the layout order.

impl Layout

Methods for arranging instructions.

An instruction starts out as not inserted in the layout. An instruction can be inserted into an EBB at a given position.

pub fn inst_ebb(&self, inst: Inst) -> Option<Ebb>

Get the EBB containing inst, or None if inst is not inserted in the layout.

pub fn pp_ebb<PP>(&self, pp: PP) -> Ebb where
    PP: Into<ExpandedProgramPoint>, 

Get the EBB containing the program point pp. Panic if pp is not in the layout.

pub fn append_inst(&mut self, inst: Inst, ebb: Ebb)

Append inst to the end of ebb.

pub fn first_inst(&self, ebb: Ebb) -> Option<Inst>

Fetch an ebb's first instruction.

pub fn last_inst(&self, ebb: Ebb) -> Option<Inst>

Fetch an ebb's last instruction.

pub fn next_inst(&self, inst: Inst) -> Option<Inst>

Fetch the instruction following inst.

pub fn prev_inst(&self, inst: Inst) -> Option<Inst>

Fetch the instruction preceding inst.

pub fn insert_inst(&mut self, inst: Inst, before: Inst)

Insert inst before the instruction before in the same EBB.

pub fn remove_inst(&mut self, inst: Inst)

Remove inst from the layout.

Important traits for Insts<'f>

impl<'f> Iterator for Insts<'f> type Item = Inst;

pub fn ebb_insts(&self, ebb: Ebb) -> Insts

Iterate over the instructions in ebb in layout order.

pub fn split_ebb(&mut self, new_ebb: Ebb, before: Inst)

Split the EBB containing before in two.

Insert new_ebb after the old EBB and move before and the following instructions to new_ebb:

old_ebb:
    i1
    i2
    i3 << before
    i4

becomes:

old_ebb:
    i1
    i2
new_ebb:
    i3 << before
    i4

Trait Implementations

impl ProgramOrder for Layout

fn cmp<A, B>(&self, a: A, b: B) -> Ordering where
    A: Into<ExpandedProgramPoint>,
    B: Into<ExpandedProgramPoint>, 

Compare the program points a and b relative to this program order.

fn is_ebb_gap(&self, inst: Inst, ebb: Ebb) -> bool

Is the range from inst to ebb just the gap between consecutive EBBs?

impl<'f> IntoIterator for &'f Layout

Use a layout reference in a for loop.

type Item = Ebb

The type of the elements being iterated over.

type IntoIter = Ebbs<'f>

Which kind of iterator are we turning this into?

Important traits for Ebbs<'f>

impl<'f> Iterator for Ebbs<'f> type Item = Ebb;

fn into_iter(self) -> Ebbs<'f>

Creates an iterator from a value.

impl Clone for Layout

fn clone(&self) -> Layout

Returns a copy of the value.

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

Performs copy-assignment from source.