Struct cranelift_codegen::ir::function::FunctionStencil

pub struct FunctionStencil {
    pub version_marker: VersionMarker,
    pub signature: Signature,
    pub sized_stack_slots: StackSlots,
    pub dynamic_stack_slots: DynamicStackSlots,
    pub global_values: PrimaryMap<GlobalValue, GlobalValueData>,
    pub heaps: PrimaryMap<Heap, HeapData>,
    pub tables: PrimaryMap<Table, TableData>,
    pub jump_tables: JumpTables,
    pub dfg: DataFlowGraph,
    pub layout: Layout,
    pub srclocs: SecondaryMap<Inst, RelSourceLoc>,
    pub stack_limit: Option<GlobalValue>,
}

Function fields needed when compiling a function.

Additionally, these fields can be the same for two functions that would be compiled the same way, and finalized by applying FunctionParameters onto their CompiledCodeStencil.

Fields

version_marker: VersionMarker

A version marker used to ensure that serialized clif ir is never deserialized with a different version of Cranelift.

signature: Signature

Signature of this function.

sized_stack_slots: StackSlots

Sized stack slots allocated in this function.

dynamic_stack_slots: DynamicStackSlots

Dynamic stack slots allocated in this function.

global_values: PrimaryMap<GlobalValue, GlobalValueData>

Global values referenced.

heaps: PrimaryMap<Heap, HeapData>

Heaps referenced.

tables: PrimaryMap<Table, TableData>

Tables referenced.

jump_tables: JumpTables

Jump tables used in this function.

dfg: DataFlowGraph

Data flow graph containing the primary definition of all instructions, blocks and values.

layout: Layout

Layout of blocks and instructions in the function body.

srclocs: SecondaryMap<Inst, RelSourceLoc>

Source locations.

Track the original source location for each instruction. The source locations are not interpreted by Cranelift, only preserved.

stack_limit: Option<GlobalValue>

An optional global value which represents an expression evaluating to the stack limit for this function. This GlobalValue will be interpreted in the prologue, if necessary, to insert a stack check to ensure that a trap happens if the stack pointer goes below the threshold specified here.

Implementations

impl FunctionStencil

pub fn create_jump_table(&mut self, data: JumpTableData) -> JumpTable

Creates a jump table in the function, to be used by br_table instructions.

pub fn create_sized_stack_slot(&mut self, data: StackSlotData) -> StackSlot

Creates a sized stack slot in the function, to be used by stack_load, stack_store and stack_addr instructions.

pub fn create_dynamic_stack_slot(
    &mut self,
    data: DynamicStackSlotData
) -> DynamicStackSlot

Creates a dynamic stack slot in the function, to be used by dynamic_stack_load, dynamic_stack_store and dynamic_stack_addr instructions.

pub fn import_signature(&mut self, signature: Signature) -> SigRef

Adds a signature which can later be used to declare an external function import.

pub fn create_global_value(&mut self, data: GlobalValueData) -> GlobalValue

Declares a global value accessible to the function.

pub fn get_dyn_scale(&self, ty: DynamicType) -> GlobalValue

Find the global dyn_scale value associated with given DynamicType

Examples found in repository

src/ir/function.rs (line 252)

    pub fn get_dynamic_slot_scale(&self, dss: DynamicStackSlot) -> GlobalValue {
        let dyn_ty = self.dynamic_stack_slots.get(dss).unwrap().dyn_ty;
        self.get_dyn_scale(dyn_ty)
    }

pub fn get_dynamic_slot_scale(&self, dss: DynamicStackSlot) -> GlobalValue

Find the global dyn_scale for the given stack slot.

pub fn get_concrete_dynamic_ty(&self, ty: DynamicType) -> Option<Type>

Get a concrete Type from a user defined DynamicType.

Examples found in repository

src/machinst/abi.rs (line 1078)

    pub fn new<'a>(
        f: &ir::Function,
        isa: &dyn TargetIsa,
        isa_flags: &M::F,
        sigs: &SigSet,
    ) -> CodegenResult<Self> {
        trace!("ABI: func signature {:?}", f.signature);

        let flags = isa.flags().clone();
        let sig = sigs.abi_sig_for_signature(&f.signature);

        let call_conv = f.signature.call_conv;
        // Only these calling conventions are supported.
        debug_assert!(
            call_conv == isa::CallConv::SystemV
                || call_conv == isa::CallConv::Fast
                || call_conv == isa::CallConv::Cold
                || call_conv.extends_windows_fastcall()
                || call_conv == isa::CallConv::AppleAarch64
                || call_conv == isa::CallConv::WasmtimeSystemV
                || call_conv == isa::CallConv::WasmtimeAppleAarch64,
            "Unsupported calling convention: {:?}",
            call_conv
        );

        // Compute sized stackslot locations and total stackslot size.
        let mut sized_stack_offset: u32 = 0;
        let mut sized_stackslots = PrimaryMap::new();
        for (stackslot, data) in f.sized_stack_slots.iter() {
            let off = sized_stack_offset;
            sized_stack_offset += data.size;
            let mask = M::word_bytes() - 1;
            sized_stack_offset = (sized_stack_offset + mask) & !mask;
            debug_assert_eq!(stackslot.as_u32() as usize, sized_stackslots.len());
            sized_stackslots.push(off);
        }

        // Compute dynamic stackslot locations and total stackslot size.
        let mut dynamic_stackslots = PrimaryMap::new();
        let mut dynamic_stack_offset: u32 = sized_stack_offset;
        for (stackslot, data) in f.dynamic_stack_slots.iter() {
            debug_assert_eq!(stackslot.as_u32() as usize, dynamic_stackslots.len());
            let off = dynamic_stack_offset;
            let ty = f
                .get_concrete_dynamic_ty(data.dyn_ty)
                .unwrap_or_else(|| panic!("invalid dynamic vector type: {}", data.dyn_ty));
            dynamic_stack_offset += isa.dynamic_vector_bytes(ty);
            let mask = M::word_bytes() - 1;
            dynamic_stack_offset = (dynamic_stack_offset + mask) & !mask;
            dynamic_stackslots.push(off);
        }
        let stackslots_size = dynamic_stack_offset;

        let mut dynamic_type_sizes = HashMap::with_capacity(f.dfg.dynamic_types.len());
        for (dyn_ty, _data) in f.dfg.dynamic_types.iter() {
            let ty = f
                .get_concrete_dynamic_ty(dyn_ty)
                .unwrap_or_else(|| panic!("invalid dynamic vector type: {}", dyn_ty));
            let size = isa.dynamic_vector_bytes(ty);
            dynamic_type_sizes.insert(ty, size);
        }

        // Figure out what instructions, if any, will be needed to check the
        // stack limit. This can either be specified as a special-purpose
        // argument or as a global value which often calculates the stack limit
        // from the arguments.
        let stack_limit =
            get_special_purpose_param_register(f, sigs, &sig, ir::ArgumentPurpose::StackLimit)
                .map(|reg| (reg, smallvec![]))
                .or_else(|| {
                    f.stack_limit
                        .map(|gv| gen_stack_limit::<M>(f, sigs, &sig, gv))
                });

        // Determine whether a probestack call is required for large enough
        // frames (and the minimum frame size if so).
        let probestack_min_frame = if flags.enable_probestack() {
            assert!(
                !flags.probestack_func_adjusts_sp(),
                "SP-adjusting probestack not supported in new backends"
            );
            Some(1 << flags.probestack_size_log2())
        } else {
            None
        };

        Ok(Self {
            ir_sig: ensure_struct_return_ptr_is_returned(&f.signature),
            sig,
            dynamic_stackslots,
            dynamic_type_sizes,
            sized_stackslots,
            stackslots_size,
            outgoing_args_size: 0,
            reg_args: vec![],
            clobbered: vec![],
            spillslots: None,
            fixed_frame_storage_size: 0,
            total_frame_size: None,
            ret_area_ptr: None,
            arg_temp_reg: vec![],
            call_conv,
            flags,
            isa_flags: isa_flags.clone(),
            is_leaf: f.is_leaf(),
            stack_limit,
            probestack_min_frame,
            setup_frame: true,
            _mach: PhantomData,
        })
    }

pub fn create_heap(&mut self, data: HeapData) -> Heap

Declares a heap accessible to the function.

pub fn create_table(&mut self, data: TableData) -> Table

Declares a table accessible to the function.

pub fn special_param(&self, purpose: ArgumentPurpose) -> Option<Value>

Find a presumed unique special-purpose function parameter value.

Returns the value of the last purpose parameter, or None if no such parameter exists.

Examples found in repository

src/legalizer/globalvalue.rs (line 58)

fn vmctx_addr(inst: ir::Inst, func: &mut ir::Function) {
    // Get the value representing the `vmctx` argument.
    let vmctx = func
        .special_param(ir::ArgumentPurpose::VMContext)
        .expect("Missing vmctx parameter");

    // Replace the `global_value` instruction's value with an alias to the vmctx arg.
    let result = func.dfg.first_result(inst);
    func.dfg.clear_results(inst);
    func.dfg.change_to_alias(result, vmctx);
    func.layout.remove_inst(inst);
}

/// Expand a `global_value` instruction for an iadd_imm global.
fn iadd_imm_addr(
    inst: ir::Inst,
    func: &mut ir::Function,
    base: ir::GlobalValue,
    offset: i64,
    global_type: ir::Type,
) {
    let mut pos = FuncCursor::new(func).at_inst(inst);

    // Get the value for the lhs. For tidiness, expand VMContext here so that we avoid
    // `vmctx_addr` which creates an otherwise unneeded value alias.
    let lhs = if let ir::GlobalValueData::VMContext = pos.func.global_values[base] {
        pos.func
            .special_param(ir::ArgumentPurpose::VMContext)
            .expect("Missing vmctx parameter")
    } else {
        pos.ins().global_value(global_type, base)
    };

    // Simply replace the `global_value` instruction with an `iadd_imm`, reusing the result value.
    pos.func.dfg.replace(inst).iadd_imm(lhs, offset);
}

/// Expand a `global_value` instruction for a load global.
fn load_addr(
    inst: ir::Inst,
    func: &mut ir::Function,
    base: ir::GlobalValue,
    offset: ir::immediates::Offset32,
    global_type: ir::Type,
    readonly: bool,
    isa: &dyn TargetIsa,
) {
    // We need to load a pointer from the `base` global value, so insert a new `global_value`
    // instruction. This depends on the iterative legalization loop. Note that the IR verifier
    // detects any cycles in the `load` globals.
    let ptr_ty = isa.pointer_type();
    let mut pos = FuncCursor::new(func).at_inst(inst);
    pos.use_srcloc(inst);

    // Get the value for the base. For tidiness, expand VMContext here so that we avoid
    // `vmctx_addr` which creates an otherwise unneeded value alias.
    let base_addr = if let ir::GlobalValueData::VMContext = pos.func.global_values[base] {
        pos.func
            .special_param(ir::ArgumentPurpose::VMContext)
            .expect("Missing vmctx parameter")
    } else {
        pos.ins().global_value(ptr_ty, base)
    };

    // Global-value loads are always notrap and aligned. They may be readonly.
    let mut mflags = ir::MemFlags::trusted();
    if readonly {
        mflags.set_readonly();
    }

    // Perform the load.
    pos.func
        .dfg
        .replace(inst)
        .load(global_type, mflags, base_addr, offset);
}

src/machinst/lower.rs (line 563)

    fn gen_arg_setup(&mut self) {
        if let Some(entry_bb) = self.f.layout.entry_block() {
            trace!(
                "gen_arg_setup: entry BB {} args are:\n{:?}",
                entry_bb,
                self.f.dfg.block_params(entry_bb)
            );

            // Make the vmctx available in debuginfo.
            if let Some(vmctx_val) = self.f.special_param(ArgumentPurpose::VMContext) {
                self.emit_value_label_marks_for_value(vmctx_val);
            }

            for (i, param) in self.f.dfg.block_params(entry_bb).iter().enumerate() {
                if !self.vcode.abi().arg_is_needed_in_body(i) {
                    continue;
                }
                let regs = writable_value_regs(self.value_regs[*param]);
                for insn in self
                    .vcode
                    .vcode
                    .abi
                    .gen_copy_arg_to_regs(&self.vcode.vcode.sigs, i, regs, &mut self.vregs)
                    .into_iter()
                {
                    self.emit(insn);
                }
                if self.abi().signature().params[i].purpose == ArgumentPurpose::StructReturn {
                    assert!(regs.len() == 1);
                    let ty = self.abi().signature().params[i].value_type;
                    // The ABI implementation must have ensured that a StructReturn
                    // arg is present in the return values.
                    assert!(self
                        .abi()
                        .signature()
                        .returns
                        .iter()
                        .position(|ret| ret.purpose == ArgumentPurpose::StructReturn)
                        .is_some());
                    self.emit(I::gen_move(
                        Writable::from_reg(self.sret_reg.unwrap().regs()[0]),
                        regs.regs()[0].to_reg(),
                        ty,
                    ));
                }
            }
            if let Some(insn) = self
                .vcode
                .vcode
                .abi
                .gen_retval_area_setup(&self.vcode.vcode.sigs, &mut self.vregs)
            {
                self.emit(insn);
            }

            // The `args` instruction below must come first. Finish
            // the current "IR inst" (with a default source location,
            // as for other special instructions inserted during
            // lowering) and continue the scan backward.
            self.finish_ir_inst(Default::default());

            if let Some(insn) = self.vcode.vcode.abi.take_args() {
                self.emit(insn);
            }
        }
    }

    /// Generate the return instruction.
    pub fn gen_return(&mut self, rets: Vec<ValueRegs<Reg>>) {
        let mut out_rets = vec![];

        let mut rets = rets.into_iter();
        for (i, ret) in self
            .abi()
            .signature()
            .returns
            .clone()
            .into_iter()
            .enumerate()
        {
            let regs = if ret.purpose == ArgumentPurpose::StructReturn {
                self.sret_reg.unwrap().clone()
            } else {
                rets.next().unwrap()
            };

            let (regs, insns) = self.vcode.abi().gen_copy_regs_to_retval(
                self.vcode.sigs(),
                i,
                regs,
                &mut self.vregs,
            );
            out_rets.extend(regs);
            for insn in insns {
                self.emit(insn);
            }
        }

        // Hack: generate a virtual instruction that uses vmctx in
        // order to keep it alive for the duration of the function,
        // for the benefit of debuginfo.
        if self.f.dfg.values_labels.is_some() {
            if let Some(vmctx_val) = self.f.special_param(ArgumentPurpose::VMContext) {
                let vmctx_reg = self.value_regs[vmctx_val].only_reg().unwrap();
                self.emit(I::gen_dummy_use(vmctx_reg));
            }
        }

        let inst = self.abi().gen_ret(out_rets);
        self.emit(inst);
    }

src/verifier/mod.rs (line 360)

    fn verify_global_values(&self, errors: &mut VerifierErrors) -> VerifierStepResult<()> {
        let mut cycle_seen = false;
        let mut seen = SparseSet::new();

        'gvs: for gv in self.func.global_values.keys() {
            seen.clear();
            seen.insert(gv);

            let mut cur = gv;
            loop {
                match self.func.global_values[cur] {
                    ir::GlobalValueData::Load { base, .. }
                    | ir::GlobalValueData::IAddImm { base, .. } => {
                        if seen.insert(base).is_some() {
                            if !cycle_seen {
                                errors.report((
                                    gv,
                                    format!("global value cycle: {}", DisplayList(seen.as_slice())),
                                ));
                                // ensures we don't report the cycle multiple times
                                cycle_seen = true;
                            }
                            continue 'gvs;
                        }

                        cur = base;
                    }
                    _ => break,
                }
            }

            match self.func.global_values[gv] {
                ir::GlobalValueData::VMContext { .. } => {
                    if self
                        .func
                        .special_param(ir::ArgumentPurpose::VMContext)
                        .is_none()
                    {
                        errors.report((gv, format!("undeclared vmctx reference {}", gv)));
                    }
                }
                ir::GlobalValueData::IAddImm {
                    base, global_type, ..
                } => {
                    if !global_type.is_int() {
                        errors.report((
                            gv,
                            format!("iadd_imm global value with non-int type {}", global_type),
                        ));
                    } else if let Some(isa) = self.isa {
                        let base_type = self.func.global_values[base].global_type(isa);
                        if global_type != base_type {
                            errors.report((
                                gv,
                                format!(
                                    "iadd_imm type {} differs from operand type {}",
                                    global_type, base_type
                                ),
                            ));
                        }
                    }
                }
                ir::GlobalValueData::Load { base, .. } => {
                    if let Some(isa) = self.isa {
                        let base_type = self.func.global_values[base].global_type(isa);
                        let pointer_type = isa.pointer_type();
                        if base_type != pointer_type {
                            errors.report((
                                gv,
                                format!(
                                    "base {} has type {}, which is not the pointer type {}",
                                    base, base_type, pointer_type
                                ),
                            ));
                        }
                    }
                }
                _ => {}
            }
        }

        // Invalid global values shouldn't stop us from verifying the rest of the function
        Ok(())
    }

pub fn collect_debug_info(&mut self)

Starts collection of debug information.

pub fn change_branch_destination(&mut self, inst: Inst, new_dest: Block)

Changes the destination of a jump or branch instruction. Does nothing if called with a non-jump or non-branch instruction.

Note that this method ignores multi-destination branches like br_table.

Examples found in repository

src/ir/function.rs (line 309)

    pub fn rewrite_branch_destination(&mut self, inst: Inst, old_dest: Block, new_dest: Block) {
        match self.dfg.analyze_branch(inst) {
            BranchInfo::SingleDest(dest, ..) => {
                if dest == old_dest {
                    self.change_branch_destination(inst, new_dest);
                }
            }

            BranchInfo::Table(table, default_dest) => {
                self.jump_tables[table].iter_mut().for_each(|entry| {
                    if *entry == old_dest {
                        *entry = new_dest;
                    }
                });

                if default_dest == Some(old_dest) {
                    match &mut self.dfg[inst] {
                        InstructionData::BranchTable { destination, .. } => {
                            *destination = new_dest;
                        }
                        _ => panic!(
                            "Unexpected instruction {} having default destination",
                            self.dfg.display_inst(inst)
                        ),
                    }
                }
            }

            BranchInfo::NotABranch => {}
        }
    }

pub fn rewrite_branch_destination(
    &mut self,
    inst: Inst,
    old_dest: Block,
    new_dest: Block
)

Rewrite the branch destination to new_dest if the destination matches old_dest. Does nothing if called with a non-jump or non-branch instruction.

Unlike change_branch_destination, this method rewrite the destinations of multi-destination branches like br_table.

Examples found in repository

src/licm.rs (line 88)

fn create_pre_header(
    header: Block,
    func: &mut Function,
    cfg: &mut ControlFlowGraph,
    domtree: &DominatorTree,
) -> Block {
    let pool = &mut ListPool::<Value>::new();
    let header_args_values = func.dfg.block_params(header).to_vec();
    let header_args_types: Vec<Type> = header_args_values
        .into_iter()
        .map(|val| func.dfg.value_type(val))
        .collect();
    let pre_header = func.dfg.make_block();
    let mut pre_header_args_value: EntityList<Value> = EntityList::new();
    for typ in header_args_types {
        pre_header_args_value.push(func.dfg.append_block_param(pre_header, typ), pool);
    }

    for BlockPredecessor {
        inst: last_inst, ..
    } in cfg.pred_iter(header)
    {
        // We only follow normal edges (not the back edges)
        if !domtree.dominates(header, last_inst, &func.layout) {
            func.rewrite_branch_destination(last_inst, header, pre_header);
        }
    }

    // Inserts the pre-header at the right place in the layout.
    let mut pos = FuncCursor::new(func).at_top(header);
    pos.insert_block(pre_header);
    pos.next_inst();
    pos.ins().jump(header, pre_header_args_value.as_slice(pool));

    pre_header
}

pub fn is_block_basic(&self, block: Block) -> Result<(), (Inst, &'static str)>

Checks that the specified block can be encoded as a basic block.

On error, returns the first invalid instruction and an error message.

Examples found in repository

src/verifier/mod.rs (line 508)

    fn encodable_as_bb(&self, block: Block, errors: &mut VerifierErrors) -> VerifierStepResult<()> {
        match self.func.is_block_basic(block) {
            Ok(()) => Ok(()),
            Err((inst, message)) => errors.fatal((inst, self.context(inst), message)),
        }
    }

pub fn is_leaf(&self) -> bool

Returns true if the function is function that doesn’t call any other functions. This is not to be confused with a “leaf function” in Windows terminology.

Examples found in repository

src/machinst/abi.rs (line 1138)

    pub fn new<'a>(
        f: &ir::Function,
        isa: &dyn TargetIsa,
        isa_flags: &M::F,
        sigs: &SigSet,
    ) -> CodegenResult<Self> {
        trace!("ABI: func signature {:?}", f.signature);

        let flags = isa.flags().clone();
        let sig = sigs.abi_sig_for_signature(&f.signature);

        let call_conv = f.signature.call_conv;
        // Only these calling conventions are supported.
        debug_assert!(
            call_conv == isa::CallConv::SystemV
                || call_conv == isa::CallConv::Fast
                || call_conv == isa::CallConv::Cold
                || call_conv.extends_windows_fastcall()
                || call_conv == isa::CallConv::AppleAarch64
                || call_conv == isa::CallConv::WasmtimeSystemV
                || call_conv == isa::CallConv::WasmtimeAppleAarch64,
            "Unsupported calling convention: {:?}",
            call_conv
        );

        // Compute sized stackslot locations and total stackslot size.
        let mut sized_stack_offset: u32 = 0;
        let mut sized_stackslots = PrimaryMap::new();
        for (stackslot, data) in f.sized_stack_slots.iter() {
            let off = sized_stack_offset;
            sized_stack_offset += data.size;
            let mask = M::word_bytes() - 1;
            sized_stack_offset = (sized_stack_offset + mask) & !mask;
            debug_assert_eq!(stackslot.as_u32() as usize, sized_stackslots.len());
            sized_stackslots.push(off);
        }

        // Compute dynamic stackslot locations and total stackslot size.
        let mut dynamic_stackslots = PrimaryMap::new();
        let mut dynamic_stack_offset: u32 = sized_stack_offset;
        for (stackslot, data) in f.dynamic_stack_slots.iter() {
            debug_assert_eq!(stackslot.as_u32() as usize, dynamic_stackslots.len());
            let off = dynamic_stack_offset;
            let ty = f
                .get_concrete_dynamic_ty(data.dyn_ty)
                .unwrap_or_else(|| panic!("invalid dynamic vector type: {}", data.dyn_ty));
            dynamic_stack_offset += isa.dynamic_vector_bytes(ty);
            let mask = M::word_bytes() - 1;
            dynamic_stack_offset = (dynamic_stack_offset + mask) & !mask;
            dynamic_stackslots.push(off);
        }
        let stackslots_size = dynamic_stack_offset;

        let mut dynamic_type_sizes = HashMap::with_capacity(f.dfg.dynamic_types.len());
        for (dyn_ty, _data) in f.dfg.dynamic_types.iter() {
            let ty = f
                .get_concrete_dynamic_ty(dyn_ty)
                .unwrap_or_else(|| panic!("invalid dynamic vector type: {}", dyn_ty));
            let size = isa.dynamic_vector_bytes(ty);
            dynamic_type_sizes.insert(ty, size);
        }

        // Figure out what instructions, if any, will be needed to check the
        // stack limit. This can either be specified as a special-purpose
        // argument or as a global value which often calculates the stack limit
        // from the arguments.
        let stack_limit =
            get_special_purpose_param_register(f, sigs, &sig, ir::ArgumentPurpose::StackLimit)
                .map(|reg| (reg, smallvec![]))
                .or_else(|| {
                    f.stack_limit
                        .map(|gv| gen_stack_limit::<M>(f, sigs, &sig, gv))
                });

        // Determine whether a probestack call is required for large enough
        // frames (and the minimum frame size if so).
        let probestack_min_frame = if flags.enable_probestack() {
            assert!(
                !flags.probestack_func_adjusts_sp(),
                "SP-adjusting probestack not supported in new backends"
            );
            Some(1 << flags.probestack_size_log2())
        } else {
            None
        };

        Ok(Self {
            ir_sig: ensure_struct_return_ptr_is_returned(&f.signature),
            sig,
            dynamic_stackslots,
            dynamic_type_sizes,
            sized_stackslots,
            stackslots_size,
            outgoing_args_size: 0,
            reg_args: vec![],
            clobbered: vec![],
            spillslots: None,
            fixed_frame_storage_size: 0,
            total_frame_size: None,
            ret_area_ptr: None,
            arg_temp_reg: vec![],
            call_conv,
            flags,
            isa_flags: isa_flags.clone(),
            is_leaf: f.is_leaf(),
            stack_limit,
            probestack_min_frame,
            setup_frame: true,
            _mach: PhantomData,
        })
    }

pub fn transplant_inst(&mut self, dst: Inst, src: Inst)

Replace the dst instruction’s data with the src instruction’s data and then remove src.

src and its result values should not be used at all, as any uses would be left dangling after calling this method.

src and dst must have the same number of resulting values, and src’s i^th value must have the same type as dst’s i^th value.

pub fn fixed_stack_size(&self) -> u32

Size occupied by all stack slots associated with this function.

Does not include any padding necessary due to offsets

Trait Implementations

impl Clone for FunctionStencil

fn clone(&self) -> FunctionStencil

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Hash for FunctionStencil

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where
    H: Hasher,
    Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq<FunctionStencil> for FunctionStencil

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

This method tests for self and other values to be equal, and is used by ==.

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

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

impl StructuralPartialEq for FunctionStencil