Struct cranelift_codegen::ir::entities::DynamicStackSlot

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pub struct DynamicStackSlot(_);

Expand description

An opaque reference to a dynamic stack slot.

Implementations§

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impl DynamicStackSlot

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pub fn from_u32(x: u32) -> Self

Create a new instance from a u32.

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pub fn as_u32(self) -> u32

Return the underlying index value as a u32.

Examples found in repository ?

src/machinst/abi.rs (line 1075)

    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,
        })
    }