wasmer_compiler_cranelift/

func_environ.rs

// This file contains code from external sources.
// Attributions: https://github.com/wasmerio/wasmer/blob/main/docs/ATTRIBUTIONS.md

use crate::{
    HashMap,
    heap::{Heap, HeapData, HeapStyle},
    table::{TableData, TableSize},
    translator::{
        EXN_REF_TYPE, FuncEnvironment as BaseFuncEnvironment, GlobalVariable, LandingPad, TAG_TYPE,
        TargetEnvironment,
    },
};
use cranelift_codegen::{
    cursor::FuncCursor,
    ir::{
        self, AbiParam, ArgumentPurpose, BlockArg, Endianness, ExceptionTableData,
        ExceptionTableItem, ExceptionTag, Function, InstBuilder, MemFlags, Signature,
        UserExternalName,
        condcodes::IntCC,
        immediates::{Offset32, Uimm64},
        types::*,
    },
    isa::TargetFrontendConfig,
};
use cranelift_frontend::FunctionBuilder;
use smallvec::SmallVec;
use std::convert::TryFrom;
use wasmer_compiler::wasmparser::HeapType;
use wasmer_types::{
    FunctionIndex, FunctionType, GlobalIndex, LocalFunctionIndex, MemoryIndex, MemoryStyle,
    ModuleInfo, SignatureIndex, TableIndex, TableStyle, TagIndex, Type as WasmerType,
    VMBuiltinFunctionIndex, VMOffsets, WasmError, WasmResult,
    entity::{EntityRef, PrimaryMap, SecondaryMap},
};

/// Compute an `ir::ExternalName` for a given wasm function index.
pub fn get_function_name(func: &mut Function, func_index: FunctionIndex) -> ir::ExternalName {
    ir::ExternalName::user(
        func.params
            .ensure_user_func_name(UserExternalName::new(0, func_index.as_u32())),
    )
}

/// The type of the `current_elements` field.
#[allow(unused)]
pub fn type_of_vmtable_definition_current_elements(vmoffsets: &VMOffsets) -> ir::Type {
    ir::Type::int(u16::from(vmoffsets.size_of_vmtable_definition_current_elements()) * 8).unwrap()
}

#[derive(Clone)]
struct ExceptionFieldLayout {
    offset: u32,
    ty: ir::Type,
}

#[derive(Clone)]
struct ExceptionTypeLayout {
    fields: SmallVec<[ExceptionFieldLayout; 4]>,
}

/// The `FuncEnvironment` implementation for use by the `ModuleEnvironment`.
pub struct FuncEnvironment<'module_environment> {
    /// Target-specified configuration.
    target_config: TargetFrontendConfig,

    /// The module-level environment which this function-level environment belongs to.
    module: &'module_environment ModuleInfo,

    /// A stack tracking the type of local variables.
    type_stack: Vec<WasmerType>,

    /// The module function signatures
    signatures: &'module_environment PrimaryMap<SignatureIndex, ir::Signature>,

    /// Heaps implementing WebAssembly linear memories.
    heaps: PrimaryMap<Heap, HeapData>,

    /// The Cranelift global holding the vmctx address.
    vmctx: Option<ir::GlobalValue>,

    /// The external function signature for implementing wasm's `memory.size`
    /// for locally-defined 32-bit memories.
    memory32_size_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `table.size`
    /// for locally-defined tables.
    table_size_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `memory.grow`
    /// for locally-defined memories.
    memory_grow_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `table.grow`
    /// for locally-defined tables.
    table_grow_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `table.copy`
    /// (it's the same for both local and imported tables).
    table_copy_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `table.init`.
    table_init_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `elem.drop`.
    elem_drop_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `memory.copy`
    /// (it's the same for both local and imported memories).
    memory_copy_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `memory.fill`
    /// (it's the same for both local and imported memories).
    memory_fill_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `memory.init`.
    memory_init_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `data.drop`.
    data_drop_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `table.get`.
    table_get_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `table.set`.
    table_set_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `func.ref`.
    func_ref_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `table.fill`.
    table_fill_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `memory32.atomic.wait32`.
    memory32_atomic_wait32_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `memory32.atomic.wait64`.
    memory32_atomic_wait64_sig: Option<ir::SigRef>,

    /// The external function signature for implementing wasm's `memory32.atomic.notify`.
    memory32_atomic_notify_sig: Option<ir::SigRef>,

    /// Cached signatures for exception helper builtins.
    personality2_sig: Option<ir::SigRef>,
    throw_sig: Option<ir::SigRef>,
    alloc_exception_sig: Option<ir::SigRef>,
    read_exception_sig: Option<ir::SigRef>,
    read_exnref_sig: Option<ir::SigRef>,

    /// Cached payload layouts for exception tags.
    exception_type_layouts: HashMap<u32, ExceptionTypeLayout>,

    /// Offsets to struct fields accessed by JIT code.
    offsets: VMOffsets,

    /// The memory styles
    memory_styles: &'module_environment PrimaryMap<MemoryIndex, MemoryStyle>,

    /// Cranelift tables we have created to implement Wasm tables.
    tables: SecondaryMap<TableIndex, Option<TableData>>,

    table_styles: &'module_environment PrimaryMap<TableIndex, TableStyle>,
}

impl<'module_environment> FuncEnvironment<'module_environment> {
    pub fn new(
        target_config: TargetFrontendConfig,
        module: &'module_environment ModuleInfo,
        signatures: &'module_environment PrimaryMap<SignatureIndex, ir::Signature>,
        memory_styles: &'module_environment PrimaryMap<MemoryIndex, MemoryStyle>,
        table_styles: &'module_environment PrimaryMap<TableIndex, TableStyle>,
    ) -> Self {
        Self {
            target_config,
            module,
            signatures,
            type_stack: vec![],
            heaps: PrimaryMap::new(),
            vmctx: None,
            memory32_size_sig: None,
            table_size_sig: None,
            memory_grow_sig: None,
            table_grow_sig: None,
            table_copy_sig: None,
            table_init_sig: None,
            elem_drop_sig: None,
            memory_copy_sig: None,
            memory_fill_sig: None,
            memory_init_sig: None,
            table_get_sig: None,
            table_set_sig: None,
            data_drop_sig: None,
            func_ref_sig: None,
            table_fill_sig: None,
            memory32_atomic_wait32_sig: None,
            memory32_atomic_wait64_sig: None,
            memory32_atomic_notify_sig: None,
            personality2_sig: None,
            throw_sig: None,
            alloc_exception_sig: None,
            read_exception_sig: None,
            read_exnref_sig: None,
            exception_type_layouts: HashMap::new(),
            offsets: VMOffsets::new(target_config.pointer_bytes(), module),
            memory_styles,
            tables: Default::default(),
            table_styles,
        }
    }

    fn pointer_type(&self) -> ir::Type {
        self.target_config.pointer_type()
    }

    fn ensure_table_exists(&mut self, func: &mut ir::Function, index: TableIndex) {
        if self.tables[index].is_some() {
            return;
        }

        let pointer_type = self.pointer_type();

        let (ptr, base_offset, current_elements_offset) = {
            let vmctx = self.vmctx(func);
            if let Some(def_index) = self.module.local_table_index(index) {
                let base_offset =
                    i32::try_from(self.offsets.vmctx_vmtable_definition_base(def_index)).unwrap();
                let current_elements_offset = i32::try_from(
                    self.offsets
                        .vmctx_vmtable_definition_current_elements(def_index),
                )
                .unwrap();
                (vmctx, base_offset, current_elements_offset)
            } else {
                let from_offset = self.offsets.vmctx_vmtable_import(index);
                let table = func.create_global_value(ir::GlobalValueData::Load {
                    base: vmctx,
                    offset: Offset32::new(i32::try_from(from_offset).unwrap()),
                    global_type: pointer_type,
                    flags: MemFlags::trusted().with_readonly(),
                });
                let base_offset = i32::from(self.offsets.vmtable_definition_base());
                let current_elements_offset =
                    i32::from(self.offsets.vmtable_definition_current_elements());
                (table, base_offset, current_elements_offset)
            }
        };

        let table = &self.module.tables[index];
        let element_size = self.reference_type().bytes();

        let base_gv = func.create_global_value(ir::GlobalValueData::Load {
            base: ptr,
            offset: Offset32::new(base_offset),
            global_type: pointer_type,
            flags: if Some(table.minimum) == table.maximum {
                // A fixed-size table can't be resized so its base address won't
                // change.
                MemFlags::trusted().with_readonly()
            } else {
                MemFlags::trusted()
            },
        });

        let bound = if Some(table.minimum) == table.maximum {
            TableSize::Static {
                bound: table.minimum,
            }
        } else {
            TableSize::Dynamic {
                bound_gv: func.create_global_value(ir::GlobalValueData::Load {
                    base: ptr,
                    offset: Offset32::new(current_elements_offset),
                    global_type: ir::Type::int(
                        u16::from(self.offsets.size_of_vmtable_definition_current_elements()) * 8,
                    )
                    .unwrap(),
                    flags: MemFlags::trusted(),
                }),
            }
        };

        self.tables[index] = Some(TableData {
            base_gv,
            bound,
            element_size,
        });
    }

    fn vmctx(&mut self, func: &mut Function) -> ir::GlobalValue {
        self.vmctx.unwrap_or_else(|| {
            let vmctx = func.create_global_value(ir::GlobalValueData::VMContext);
            self.vmctx = Some(vmctx);
            vmctx
        })
    }

    fn get_table_fill_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.table_fill_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    // table index
                    AbiParam::new(I32),
                    // dst
                    AbiParam::new(I32),
                    // value
                    AbiParam::new(self.reference_type()),
                    // len
                    AbiParam::new(I32),
                ],
                returns: vec![],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.table_fill_sig = Some(sig);
        sig
    }

    fn get_table_fill_func(
        &mut self,
        func: &mut Function,
        table_index: TableIndex,
    ) -> (ir::SigRef, usize, VMBuiltinFunctionIndex) {
        (
            self.get_table_fill_sig(func),
            table_index.index(),
            VMBuiltinFunctionIndex::get_table_fill_index(),
        )
    }

    fn get_func_ref_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.func_ref_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    AbiParam::new(I32),
                ],
                returns: vec![AbiParam::new(self.reference_type())],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.func_ref_sig = Some(sig);
        sig
    }

    fn get_func_ref_func(
        &mut self,
        func: &mut Function,
        function_index: FunctionIndex,
    ) -> (ir::SigRef, usize, VMBuiltinFunctionIndex) {
        (
            self.get_func_ref_sig(func),
            function_index.index(),
            VMBuiltinFunctionIndex::get_func_ref_index(),
        )
    }

    fn get_table_get_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.table_get_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    AbiParam::new(I32),
                    AbiParam::new(I32),
                ],
                returns: vec![AbiParam::new(self.reference_type())],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.table_get_sig = Some(sig);
        sig
    }

    fn get_table_get_func(
        &mut self,
        func: &mut Function,
        table_index: TableIndex,
    ) -> (ir::SigRef, usize, VMBuiltinFunctionIndex) {
        if self.module.is_imported_table(table_index) {
            (
                self.get_table_get_sig(func),
                table_index.index(),
                VMBuiltinFunctionIndex::get_imported_table_get_index(),
            )
        } else {
            (
                self.get_table_get_sig(func),
                self.module.local_table_index(table_index).unwrap().index(),
                VMBuiltinFunctionIndex::get_table_get_index(),
            )
        }
    }

    fn get_table_set_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.table_set_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    AbiParam::new(I32),
                    AbiParam::new(I32),
                    AbiParam::new(self.reference_type()),
                ],
                returns: vec![],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.table_set_sig = Some(sig);
        sig
    }

    fn get_table_set_func(
        &mut self,
        func: &mut Function,
        table_index: TableIndex,
    ) -> (ir::SigRef, usize, VMBuiltinFunctionIndex) {
        if self.module.is_imported_table(table_index) {
            (
                self.get_table_set_sig(func),
                table_index.index(),
                VMBuiltinFunctionIndex::get_imported_table_set_index(),
            )
        } else {
            (
                self.get_table_set_sig(func),
                self.module.local_table_index(table_index).unwrap().index(),
                VMBuiltinFunctionIndex::get_table_set_index(),
            )
        }
    }

    fn get_table_grow_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.table_grow_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    // TODO: figure out what the representation of a Wasm value is
                    AbiParam::new(self.reference_type()),
                    AbiParam::new(I32),
                    AbiParam::new(I32),
                ],
                returns: vec![AbiParam::new(I32)],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.table_grow_sig = Some(sig);
        sig
    }

    /// Return the table.grow function signature to call for the given index, along with the
    /// translated index value to pass to it and its index in `VMBuiltinFunctionsArray`.
    fn get_table_grow_func(
        &mut self,
        func: &mut Function,
        index: TableIndex,
    ) -> (ir::SigRef, usize, VMBuiltinFunctionIndex) {
        if self.module.is_imported_table(index) {
            (
                self.get_table_grow_sig(func),
                index.index(),
                VMBuiltinFunctionIndex::get_imported_table_grow_index(),
            )
        } else {
            (
                self.get_table_grow_sig(func),
                self.module.local_table_index(index).unwrap().index(),
                VMBuiltinFunctionIndex::get_table_grow_index(),
            )
        }
    }

    fn get_memory_grow_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.memory_grow_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    AbiParam::new(I32),
                    AbiParam::new(I32),
                ],
                returns: vec![AbiParam::new(I32)],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.memory_grow_sig = Some(sig);
        sig
    }

    /// Return the memory.grow function signature to call for the given index, along with the
    /// translated index value to pass to it and its index in `VMBuiltinFunctionsArray`.
    fn get_memory_grow_func(
        &mut self,
        func: &mut Function,
        index: MemoryIndex,
    ) -> (ir::SigRef, usize, VMBuiltinFunctionIndex) {
        if self.module.is_imported_memory(index) {
            (
                self.get_memory_grow_sig(func),
                index.index(),
                VMBuiltinFunctionIndex::get_imported_memory32_grow_index(),
            )
        } else {
            (
                self.get_memory_grow_sig(func),
                self.module.local_memory_index(index).unwrap().index(),
                VMBuiltinFunctionIndex::get_memory32_grow_index(),
            )
        }
    }

    fn get_table_size_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.table_size_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    AbiParam::new(I32),
                ],
                returns: vec![AbiParam::new(I32)],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.table_size_sig = Some(sig);
        sig
    }

    /// Return the memory.size function signature to call for the given index, along with the
    /// translated index value to pass to it and its index in `VMBuiltinFunctionsArray`.
    fn get_table_size_func(
        &mut self,
        func: &mut Function,
        index: TableIndex,
    ) -> (ir::SigRef, usize, VMBuiltinFunctionIndex) {
        if self.module.is_imported_table(index) {
            (
                self.get_table_size_sig(func),
                index.index(),
                VMBuiltinFunctionIndex::get_imported_table_size_index(),
            )
        } else {
            (
                self.get_table_size_sig(func),
                self.module.local_table_index(index).unwrap().index(),
                VMBuiltinFunctionIndex::get_table_size_index(),
            )
        }
    }

    fn get_memory32_size_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.memory32_size_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    AbiParam::new(I32),
                ],
                returns: vec![AbiParam::new(I32)],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.memory32_size_sig = Some(sig);
        sig
    }

    /// Return the memory.size function signature to call for the given index, along with the
    /// translated index value to pass to it and its index in `VMBuiltinFunctionsArray`.
    fn get_memory_size_func(
        &mut self,
        func: &mut Function,
        index: MemoryIndex,
    ) -> (ir::SigRef, usize, VMBuiltinFunctionIndex) {
        if self.module.is_imported_memory(index) {
            (
                self.get_memory32_size_sig(func),
                index.index(),
                VMBuiltinFunctionIndex::get_imported_memory32_size_index(),
            )
        } else {
            (
                self.get_memory32_size_sig(func),
                self.module.local_memory_index(index).unwrap().index(),
                VMBuiltinFunctionIndex::get_memory32_size_index(),
            )
        }
    }

    fn get_table_copy_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.table_copy_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    // Destination table index.
                    AbiParam::new(I32),
                    // Source table index.
                    AbiParam::new(I32),
                    // Index within destination table.
                    AbiParam::new(I32),
                    // Index within source table.
                    AbiParam::new(I32),
                    // Number of elements to copy.
                    AbiParam::new(I32),
                ],
                returns: vec![],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.table_copy_sig = Some(sig);
        sig
    }

    fn get_table_copy_func(
        &mut self,
        func: &mut Function,
        dst_table_index: TableIndex,
        src_table_index: TableIndex,
    ) -> (ir::SigRef, usize, usize, VMBuiltinFunctionIndex) {
        let sig = self.get_table_copy_sig(func);
        (
            sig,
            dst_table_index.as_u32() as usize,
            src_table_index.as_u32() as usize,
            VMBuiltinFunctionIndex::get_table_copy_index(),
        )
    }

    fn get_table_init_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.table_init_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    // Table index.
                    AbiParam::new(I32),
                    // Segment index.
                    AbiParam::new(I32),
                    // Destination index within table.
                    AbiParam::new(I32),
                    // Source index within segment.
                    AbiParam::new(I32),
                    // Number of elements to initialize.
                    AbiParam::new(I32),
                ],
                returns: vec![],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.table_init_sig = Some(sig);
        sig
    }

    fn get_table_init_func(
        &mut self,
        func: &mut Function,
        table_index: TableIndex,
    ) -> (ir::SigRef, usize, VMBuiltinFunctionIndex) {
        let sig = self.get_table_init_sig(func);
        let table_index = table_index.as_u32() as usize;
        (
            sig,
            table_index,
            VMBuiltinFunctionIndex::get_table_init_index(),
        )
    }

    fn get_elem_drop_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.elem_drop_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    // Element index.
                    AbiParam::new(I32),
                ],
                returns: vec![],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.elem_drop_sig = Some(sig);
        sig
    }

    fn get_elem_drop_func(&mut self, func: &mut Function) -> (ir::SigRef, VMBuiltinFunctionIndex) {
        let sig = self.get_elem_drop_sig(func);
        (sig, VMBuiltinFunctionIndex::get_elem_drop_index())
    }

    fn get_memory_copy_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.memory_copy_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    // Memory index.
                    AbiParam::new(I32),
                    // Destination address.
                    AbiParam::new(I32),
                    // Source address.
                    AbiParam::new(I32),
                    // Length.
                    AbiParam::new(I32),
                ],
                returns: vec![],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.memory_copy_sig = Some(sig);
        sig
    }

    fn get_memory_copy_func(
        &mut self,
        func: &mut Function,
        memory_index: MemoryIndex,
    ) -> (ir::SigRef, usize, VMBuiltinFunctionIndex) {
        let sig = self.get_memory_copy_sig(func);
        if let Some(local_memory_index) = self.module.local_memory_index(memory_index) {
            (
                sig,
                local_memory_index.index(),
                VMBuiltinFunctionIndex::get_memory_copy_index(),
            )
        } else {
            (
                sig,
                memory_index.index(),
                VMBuiltinFunctionIndex::get_imported_memory_copy_index(),
            )
        }
    }

    fn get_memory_fill_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.memory_fill_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    // Memory index.
                    AbiParam::new(I32),
                    // Destination address.
                    AbiParam::new(I32),
                    // Value.
                    AbiParam::new(I32),
                    // Length.
                    AbiParam::new(I32),
                ],
                returns: vec![],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.memory_fill_sig = Some(sig);
        sig
    }

    fn get_memory_fill_func(
        &mut self,
        func: &mut Function,
        memory_index: MemoryIndex,
    ) -> (ir::SigRef, usize, VMBuiltinFunctionIndex) {
        let sig = self.get_memory_fill_sig(func);
        if let Some(local_memory_index) = self.module.local_memory_index(memory_index) {
            (
                sig,
                local_memory_index.index(),
                VMBuiltinFunctionIndex::get_memory_fill_index(),
            )
        } else {
            (
                sig,
                memory_index.index(),
                VMBuiltinFunctionIndex::get_imported_memory_fill_index(),
            )
        }
    }

    fn get_memory_init_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.memory_init_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    // Memory index.
                    AbiParam::new(I32),
                    // Data index.
                    AbiParam::new(I32),
                    // Destination address.
                    AbiParam::new(I32),
                    // Source index within the data segment.
                    AbiParam::new(I32),
                    // Length.
                    AbiParam::new(I32),
                ],
                returns: vec![],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.memory_init_sig = Some(sig);
        sig
    }

    fn get_memory_init_func(
        &mut self,
        func: &mut Function,
    ) -> (ir::SigRef, VMBuiltinFunctionIndex) {
        let sig = self.get_memory_init_sig(func);
        (sig, VMBuiltinFunctionIndex::get_memory_init_index())
    }

    fn get_data_drop_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.data_drop_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    // Data index.
                    AbiParam::new(I32),
                ],
                returns: vec![],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.data_drop_sig = Some(sig);
        sig
    }

    fn get_data_drop_func(&mut self, func: &mut Function) -> (ir::SigRef, VMBuiltinFunctionIndex) {
        let sig = self.get_data_drop_sig(func);
        (sig, VMBuiltinFunctionIndex::get_data_drop_index())
    }

    fn get_memory32_atomic_wait32_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.memory32_atomic_wait32_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    // Memory Index
                    AbiParam::new(I32),
                    // Dst
                    AbiParam::new(I32),
                    // Val
                    AbiParam::new(I32),
                    // Timeout
                    AbiParam::new(I64),
                ],
                returns: vec![AbiParam::new(I32)],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.memory32_atomic_wait32_sig = Some(sig);
        sig
    }

    /// Return the memory.atomic.wait32 function signature to call for the given index,
    /// along with the translated index value to pass to it
    /// and its index in `VMBuiltinFunctionsArray`.
    fn get_memory_atomic_wait32_func(
        &mut self,
        func: &mut Function,
        index: MemoryIndex,
    ) -> (ir::SigRef, usize, VMBuiltinFunctionIndex) {
        if self.module.is_imported_memory(index) {
            (
                self.get_memory32_atomic_wait32_sig(func),
                index.index(),
                VMBuiltinFunctionIndex::get_imported_memory_atomic_wait32_index(),
            )
        } else {
            (
                self.get_memory32_atomic_wait32_sig(func),
                self.module.local_memory_index(index).unwrap().index(),
                VMBuiltinFunctionIndex::get_memory_atomic_wait32_index(),
            )
        }
    }

    fn get_memory32_atomic_wait64_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.memory32_atomic_wait64_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    // Memory Index
                    AbiParam::new(I32),
                    // Dst
                    AbiParam::new(I32),
                    // Val
                    AbiParam::new(I64),
                    // Timeout
                    AbiParam::new(I64),
                ],
                returns: vec![AbiParam::new(I32)],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.memory32_atomic_wait64_sig = Some(sig);
        sig
    }

    /// Return the memory.atomic.wait64 function signature to call for the given index,
    /// along with the translated index value to pass to it
    /// and its index in `VMBuiltinFunctionsArray`.
    fn get_memory_atomic_wait64_func(
        &mut self,
        func: &mut Function,
        index: MemoryIndex,
    ) -> (ir::SigRef, usize, VMBuiltinFunctionIndex) {
        if self.module.is_imported_memory(index) {
            (
                self.get_memory32_atomic_wait64_sig(func),
                index.index(),
                VMBuiltinFunctionIndex::get_imported_memory_atomic_wait64_index(),
            )
        } else {
            (
                self.get_memory32_atomic_wait64_sig(func),
                self.module.local_memory_index(index).unwrap().index(),
                VMBuiltinFunctionIndex::get_memory_atomic_wait64_index(),
            )
        }
    }

    fn get_memory32_atomic_notify_sig(&mut self, func: &mut Function) -> ir::SigRef {
        let sig = self.memory32_atomic_notify_sig.unwrap_or_else(|| {
            func.import_signature(Signature {
                params: vec![
                    AbiParam::special(self.pointer_type(), ArgumentPurpose::VMContext),
                    // Memory Index
                    AbiParam::new(I32),
                    // Dst
                    AbiParam::new(I32),
                    // Count
                    AbiParam::new(I32),
                ],
                returns: vec![AbiParam::new(I32)],
                call_conv: self.target_config.default_call_conv,
            })
        });
        self.memory32_atomic_notify_sig = Some(sig);
        sig
    }

    /// Return the memory.atomic.notify function signature to call for the given index,
    /// along with the translated index value to pass to it
    /// and its index in `VMBuiltinFunctionsArray`.
    fn get_memory_atomic_notify_func(
        &mut self,
        func: &mut Function,
        index: MemoryIndex,
    ) -> (ir::SigRef, usize, VMBuiltinFunctionIndex) {
        if self.module.is_imported_memory(index) {
            (
                self.get_memory32_atomic_notify_sig(func),
                index.index(),
                VMBuiltinFunctionIndex::get_imported_memory_atomic_notify_index(),
            )
        } else {
            (
                self.get_memory32_atomic_notify_sig(func),
                self.module.local_memory_index(index).unwrap().index(),
                VMBuiltinFunctionIndex::get_memory_atomic_notify_index(),
            )
        }
    }

    fn get_personality2_func(
        &mut self,
        func: &mut Function,
    ) -> (ir::SigRef, VMBuiltinFunctionIndex) {
        let sig = self.personality2_sig.unwrap_or_else(|| {
            let mut signature = Signature::new(self.target_config.default_call_conv);
            signature.params.push(AbiParam::new(self.pointer_type()));
            signature.params.push(AbiParam::new(self.pointer_type()));
            signature.returns.push(AbiParam::new(TAG_TYPE));
            let sig = func.import_signature(signature);
            self.personality2_sig = Some(sig);
            sig
        });
        (
            sig,
            VMBuiltinFunctionIndex::get_imported_personality2_index(),
        )
    }

    fn get_throw_func(&mut self, func: &mut Function) -> (ir::SigRef, VMBuiltinFunctionIndex) {
        let sig = self.throw_sig.unwrap_or_else(|| {
            let mut signature = Signature::new(self.target_config.default_call_conv);
            signature.params.push(AbiParam::special(
                self.pointer_type(),
                ArgumentPurpose::VMContext,
            ));
            signature.params.push(AbiParam::new(EXN_REF_TYPE));
            let sig = func.import_signature(signature);
            self.throw_sig = Some(sig);
            sig
        });
        (sig, VMBuiltinFunctionIndex::get_imported_throw_index())
    }

    fn get_alloc_exception_func(
        &mut self,
        func: &mut Function,
    ) -> (ir::SigRef, VMBuiltinFunctionIndex) {
        let sig = self.alloc_exception_sig.unwrap_or_else(|| {
            let mut signature = Signature::new(self.target_config.default_call_conv);
            signature.params.push(AbiParam::special(
                self.pointer_type(),
                ArgumentPurpose::VMContext,
            ));
            signature.params.push(AbiParam::new(TAG_TYPE));
            signature.returns.push(AbiParam::new(EXN_REF_TYPE));
            let sig = func.import_signature(signature);
            self.alloc_exception_sig = Some(sig);
            sig
        });
        (
            sig,
            VMBuiltinFunctionIndex::get_imported_alloc_exception_index(),
        )
    }

    fn get_read_exnref_func(
        &mut self,
        func: &mut Function,
    ) -> (ir::SigRef, VMBuiltinFunctionIndex) {
        let sig = self.read_exnref_sig.unwrap_or_else(|| {
            let mut signature = Signature::new(self.target_config.default_call_conv);
            signature.params.push(AbiParam::special(
                self.pointer_type(),
                ArgumentPurpose::VMContext,
            ));
            signature.params.push(AbiParam::new(EXN_REF_TYPE));
            signature.returns.push(AbiParam::new(self.pointer_type()));
            let sig = func.import_signature(signature);
            self.read_exnref_sig = Some(sig);
            sig
        });
        (
            sig,
            VMBuiltinFunctionIndex::get_imported_read_exnref_index(),
        )
    }

    fn get_read_exception_func(
        &mut self,
        func: &mut Function,
    ) -> (ir::SigRef, VMBuiltinFunctionIndex) {
        let sig = self.read_exception_sig.unwrap_or_else(|| {
            let mut signature = Signature::new(self.target_config.default_call_conv);
            signature.params.push(AbiParam::new(self.pointer_type()));
            signature.returns.push(AbiParam::new(EXN_REF_TYPE));
            let sig = func.import_signature(signature);
            self.read_exception_sig = Some(sig);
            sig
        });
        (
            sig,
            VMBuiltinFunctionIndex::get_imported_exception_into_exnref_index(),
        )
    }

    fn exception_type_layout(&mut self, tag_index: TagIndex) -> WasmResult<&ExceptionTypeLayout> {
        let key = tag_index.as_u32();
        if !self.exception_type_layouts.contains_key(&key) {
            let layout = self.compute_exception_type_layout(tag_index)?;
            self.exception_type_layouts.insert(key, layout);
        }
        Ok(self.exception_type_layouts.get(&key).unwrap())
    }

    fn compute_exception_type_layout(
        &self,
        tag_index: TagIndex,
    ) -> WasmResult<ExceptionTypeLayout> {
        let sig_index = self.module.tags[tag_index];
        let func_type = &self.module.signatures[sig_index];
        let mut offset = 0u32;
        let mut max_align = 1u32;
        let mut fields = SmallVec::<[ExceptionFieldLayout; 4]>::new();

        for wasm_ty in func_type.params() {
            let ir_ty = self.map_wasmer_type_to_ir(*wasm_ty)?;
            let field_size = ir_ty.bytes();
            let align = field_size.max(1);
            max_align = max_align.max(align);
            offset = offset.next_multiple_of(align);
            fields.push(ExceptionFieldLayout { offset, ty: ir_ty });
            offset = offset
                .checked_add(field_size)
                .ok_or_else(|| WasmError::Unsupported("exception payload too large".to_string()))?;
        }

        Ok(ExceptionTypeLayout { fields })
    }

    fn map_wasmer_type_to_ir(&self, ty: WasmerType) -> WasmResult<ir::Type> {
        Ok(match ty {
            WasmerType::I32 => ir::types::I32,
            WasmerType::I64 => ir::types::I64,
            WasmerType::F32 => ir::types::F32,
            WasmerType::F64 => ir::types::F64,
            WasmerType::V128 => ir::types::I8X16,
            WasmerType::FuncRef | WasmerType::ExternRef | WasmerType::ExceptionRef => {
                self.reference_type()
            }
        })
    }

    fn call_with_handlers(
        &mut self,
        builder: &mut FunctionBuilder,
        callee: ir::FuncRef,
        args: &[ir::Value],
        context: Option<ir::Value>,
        landing_pad: Option<LandingPad>,
        unreachable_on_return: bool,
    ) -> SmallVec<[ir::Value; 4]> {
        let sig_ref = builder.func.dfg.ext_funcs[callee].signature;
        let return_types: SmallVec<[ir::Type; 4]> = builder.func.dfg.signatures[sig_ref]
            .returns
            .iter()
            .map(|ret| ret.value_type)
            .collect();

        if landing_pad.is_none() {
            let inst = builder.ins().call(callee, args);
            let results: SmallVec<[ir::Value; 4]> =
                builder.inst_results(inst).iter().copied().collect();
            if unreachable_on_return {
                builder.ins().trap(crate::TRAP_UNREACHABLE);
            }
            return results;
        }

        let continuation = builder.create_block();
        let mut normal_args = SmallVec::<[BlockArg; 4]>::with_capacity(return_types.len());
        let mut result_values = SmallVec::<[ir::Value; 4]>::with_capacity(return_types.len());
        for (i, ty) in return_types.iter().enumerate() {
            let val = builder.append_block_param(continuation, *ty);
            result_values.push(val);
            normal_args.push(BlockArg::TryCallRet(u32::try_from(i).unwrap()));
        }
        let continuation_call = builder
            .func
            .dfg
            .block_call(continuation, normal_args.iter());

        let mut table_items = Vec::new();
        if let Some(ctx) = context {
            table_items.push(ExceptionTableItem::Context(ctx));
        }
        if let Some(landing_pad) = landing_pad {
            for tag in landing_pad.clauses {
                let block_call = builder.func.dfg.block_call(
                    landing_pad.block,
                    &[BlockArg::TryCallExn(0), BlockArg::TryCallExn(1)],
                );
                table_items.push(match tag.wasm_tag {
                    Some(tag) => ExceptionTableItem::Tag(ExceptionTag::from_u32(tag), block_call),
                    None => ExceptionTableItem::Default(block_call),
                });
            }
        }
        let etd = ExceptionTableData::new(sig_ref, continuation_call, table_items);
        let et = builder.func.dfg.exception_tables.push(etd);
        builder.ins().try_call(callee, args, et);
        builder.switch_to_block(continuation);
        builder.seal_block(continuation);
        if unreachable_on_return {
            builder.ins().trap(crate::TRAP_UNREACHABLE);
        }
        result_values
    }

    #[allow(clippy::too_many_arguments)]
    fn call_indirect_with_handlers(
        &mut self,
        builder: &mut FunctionBuilder,
        sig: ir::SigRef,
        func_addr: ir::Value,
        args: &[ir::Value],
        context: Option<ir::Value>,
        landing_pad: Option<LandingPad>,
        unreachable_on_return: bool,
    ) -> SmallVec<[ir::Value; 4]> {
        let return_types: SmallVec<[ir::Type; 4]> = builder.func.dfg.signatures[sig]
            .returns
            .iter()
            .map(|ret| ret.value_type)
            .collect();

        if landing_pad.is_none() {
            let inst = builder.ins().call_indirect(sig, func_addr, args);
            let results: SmallVec<[ir::Value; 4]> =
                builder.inst_results(inst).iter().copied().collect();
            if unreachable_on_return {
                builder.ins().trap(crate::TRAP_UNREACHABLE);
            }
            return results;
        }

        let continuation = builder.create_block();
        let current_block = builder.current_block().expect("current block");
        builder.insert_block_after(continuation, current_block);

        let mut normal_args = SmallVec::<[BlockArg; 4]>::with_capacity(return_types.len());
        let mut result_values = SmallVec::<[ir::Value; 4]>::with_capacity(return_types.len());
        for (i, ty) in return_types.iter().enumerate() {
            let val = builder.append_block_param(continuation, *ty);
            result_values.push(val);
            normal_args.push(BlockArg::TryCallRet(u32::try_from(i).unwrap()));
        }
        let continuation_call = builder
            .func
            .dfg
            .block_call(continuation, normal_args.iter());

        let mut table_items = Vec::new();
        if let Some(ctx) = context {
            table_items.push(ExceptionTableItem::Context(ctx));
        }
        if let Some(landing_pad) = landing_pad {
            for tag in landing_pad.clauses {
                let block_call = builder.func.dfg.block_call(
                    landing_pad.block,
                    &[BlockArg::TryCallExn(0), BlockArg::TryCallExn(1)],
                );
                table_items.push(match tag.wasm_tag {
                    Some(tag) => ExceptionTableItem::Tag(ExceptionTag::from_u32(tag), block_call),
                    None => ExceptionTableItem::Default(block_call),
                });
            }
        }

        let etd = ExceptionTableData::new(sig, continuation_call, table_items);
        let et = builder.func.dfg.exception_tables.push(etd);
        builder.ins().try_call_indirect(func_addr, args, et);
        builder.switch_to_block(continuation);
        builder.seal_block(continuation);
        if unreachable_on_return {
            builder.ins().trap(crate::TRAP_UNREACHABLE);
        }

        result_values
    }

    /// Translates load of builtin function and returns a pair of values `vmctx`
    /// and address of the loaded function.
    fn translate_load_builtin_function_address(
        &mut self,
        pos: &mut FuncCursor<'_>,
        callee_func_idx: VMBuiltinFunctionIndex,
    ) -> (ir::Value, ir::Value) {
        // We use an indirect call so that we don't have to patch the code at runtime.
        let pointer_type = self.pointer_type();
        let vmctx = self.vmctx(pos.func);
        let base = pos.ins().global_value(pointer_type, vmctx);

        let mut mem_flags = ir::MemFlags::trusted();
        mem_flags.set_readonly();

        // Load the callee address.
        let body_offset =
            i32::try_from(self.offsets.vmctx_builtin_function(callee_func_idx)).unwrap();
        let func_addr = pos.ins().load(pointer_type, mem_flags, base, body_offset);

        (base, func_addr)
    }

    fn get_or_init_funcref_table_elem(
        &mut self,
        builder: &mut FunctionBuilder,
        table_index: TableIndex,
        index: ir::Value,
    ) -> ir::Value {
        let pointer_type = self.pointer_type();
        self.ensure_table_exists(builder.func, table_index);
        let table_data = self.tables[table_index].as_ref().unwrap();

        // To support lazy initialization of table
        // contents, we check for a null entry here, and
        // if null, we take a slow-path that invokes a
        // libcall.
        let (table_entry_addr, flags) =
            table_data.prepare_table_addr(builder, index, pointer_type, false);
        builder.ins().load(pointer_type, flags, table_entry_addr, 0)
    }
}

impl TargetEnvironment for FuncEnvironment<'_> {
    fn target_config(&self) -> TargetFrontendConfig {
        self.target_config
    }
}

impl BaseFuncEnvironment for FuncEnvironment<'_> {
    fn is_wasm_parameter(&self, _signature: &ir::Signature, index: usize) -> bool {
        // The first parameter is the vmctx. The rest are the wasm parameters.
        index >= 1
    }

    fn translate_table_grow(
        &mut self,
        mut pos: cranelift_codegen::cursor::FuncCursor<'_>,
        table_index: TableIndex,
        delta: ir::Value,
        init_value: ir::Value,
    ) -> WasmResult<ir::Value> {
        self.ensure_table_exists(pos.func, table_index);
        let (func_sig, index_arg, func_idx) = self.get_table_grow_func(pos.func, table_index);
        let table_index = pos.ins().iconst(I32, index_arg as i64);
        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);
        let call_inst = pos.ins().call_indirect(
            func_sig,
            func_addr,
            &[vmctx, init_value, delta, table_index],
        );
        Ok(*pos.func.dfg.inst_results(call_inst).first().unwrap())
    }

    fn translate_table_get(
        &mut self,
        builder: &mut FunctionBuilder,
        table_index: TableIndex,
        index: ir::Value,
    ) -> WasmResult<ir::Value> {
        self.ensure_table_exists(builder.func, table_index);
        let mut pos = builder.cursor();

        let (func_sig, table_index_arg, func_idx) = self.get_table_get_func(pos.func, table_index);
        let table_index = pos.ins().iconst(I32, table_index_arg as i64);
        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);
        let call_inst = pos
            .ins()
            .call_indirect(func_sig, func_addr, &[vmctx, table_index, index]);
        Ok(*pos.func.dfg.inst_results(call_inst).first().unwrap())
    }

    fn translate_table_set(
        &mut self,
        builder: &mut FunctionBuilder,
        table_index: TableIndex,
        value: ir::Value,
        index: ir::Value,
    ) -> WasmResult<()> {
        self.ensure_table_exists(builder.func, table_index);
        let mut pos = builder.cursor();

        let (func_sig, table_index_arg, func_idx) = self.get_table_set_func(pos.func, table_index);
        let n_table_index = pos.ins().iconst(I32, table_index_arg as i64);
        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);
        pos.ins()
            .call_indirect(func_sig, func_addr, &[vmctx, n_table_index, index, value]);
        Ok(())
    }

    fn translate_table_fill(
        &mut self,
        mut pos: cranelift_codegen::cursor::FuncCursor<'_>,
        table_index: TableIndex,
        dst: ir::Value,
        val: ir::Value,
        len: ir::Value,
    ) -> WasmResult<()> {
        self.ensure_table_exists(pos.func, table_index);
        let (func_sig, table_index_arg, func_idx) = self.get_table_fill_func(pos.func, table_index);
        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);

        let table_index_arg = pos.ins().iconst(I32, table_index_arg as i64);
        pos.ins().call_indirect(
            func_sig,
            func_addr,
            &[vmctx, table_index_arg, dst, val, len],
        );

        Ok(())
    }

    fn translate_ref_null(
        &mut self,
        mut pos: cranelift_codegen::cursor::FuncCursor,
        ty: HeapType,
    ) -> WasmResult<ir::Value> {
        Ok(match ty {
            HeapType::Abstract { ty, .. } => match ty {
                wasmer_compiler::wasmparser::AbstractHeapType::Func
                | wasmer_compiler::wasmparser::AbstractHeapType::Extern
                | wasmer_compiler::wasmparser::AbstractHeapType::Exn => pos.ins().iconst(
                    if matches!(ty, wasmer_compiler::wasmparser::AbstractHeapType::Exn) {
                        I32
                    } else {
                        self.reference_type()
                    },
                    0,
                ),
                _ => {
                    return Err(WasmError::Unsupported(format!(
                        "`ref.null T` that is not a `funcref`, an `externref` or an `exn`: {ty:?}"
                    )));
                }
            },
            HeapType::Concrete(_) => {
                return Err(WasmError::Unsupported(
                    "`ref.null T` that is not a `funcref` or an `externref`".into(),
                ));
            }
            HeapType::Exact(_) => {
                return Err(WasmError::Unsupported(
                    "custom-descriptors not supported yet".into(),
                ));
            }
        })
    }

    fn translate_ref_is_null(
        &mut self,
        mut pos: cranelift_codegen::cursor::FuncCursor,
        value: ir::Value,
    ) -> WasmResult<ir::Value> {
        let bool_is_null =
            pos.ins()
                .icmp_imm(cranelift_codegen::ir::condcodes::IntCC::Equal, value, 0);
        Ok(pos.ins().uextend(ir::types::I32, bool_is_null))
    }

    fn translate_ref_func(
        &mut self,
        mut pos: cranelift_codegen::cursor::FuncCursor<'_>,
        func_index: FunctionIndex,
    ) -> WasmResult<ir::Value> {
        let (func_sig, func_index_arg, func_idx) = self.get_func_ref_func(pos.func, func_index);
        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);

        let func_index_arg = pos.ins().iconst(I32, func_index_arg as i64);
        let call_inst = pos
            .ins()
            .call_indirect(func_sig, func_addr, &[vmctx, func_index_arg]);

        Ok(*pos.func.dfg.inst_results(call_inst).first().unwrap())
    }

    fn translate_custom_global_get(
        &mut self,
        mut _pos: cranelift_codegen::cursor::FuncCursor<'_>,
        _index: GlobalIndex,
    ) -> WasmResult<ir::Value> {
        unreachable!("we don't make any custom globals")
    }

    fn translate_custom_global_set(
        &mut self,
        mut _pos: cranelift_codegen::cursor::FuncCursor<'_>,
        _index: GlobalIndex,
        _value: ir::Value,
    ) -> WasmResult<()> {
        unreachable!("we don't make any custom globals")
    }

    fn make_heap(&mut self, func: &mut ir::Function, index: MemoryIndex) -> WasmResult<Heap> {
        let pointer_type = self.pointer_type();

        let (ptr, base_offset, current_length_offset) = {
            let vmctx = self.vmctx(func);
            if let Some(def_index) = self.module.local_memory_index(index) {
                let base_offset =
                    i32::try_from(self.offsets.vmctx_vmmemory_definition_base(def_index)).unwrap();
                let current_length_offset = i32::try_from(
                    self.offsets
                        .vmctx_vmmemory_definition_current_length(def_index),
                )
                .unwrap();
                (vmctx, base_offset, current_length_offset)
            } else {
                let from_offset = self.offsets.vmctx_vmmemory_import_definition(index);
                let memory = func.create_global_value(ir::GlobalValueData::Load {
                    base: vmctx,
                    offset: Offset32::new(i32::try_from(from_offset).unwrap()),
                    global_type: pointer_type,
                    flags: ir::MemFlags::trusted().with_readonly(),
                });
                let base_offset = i32::from(self.offsets.vmmemory_definition_base());
                let current_length_offset =
                    i32::from(self.offsets.vmmemory_definition_current_length());
                (memory, base_offset, current_length_offset)
            }
        };

        // If we have a declared maximum, we can make this a "static" heap, which is
        // allocated up front and never moved.
        let (offset_guard_size, heap_style, readonly_base) = match self.memory_styles[index] {
            MemoryStyle::Dynamic { offset_guard_size } => {
                let heap_bound = func.create_global_value(ir::GlobalValueData::Load {
                    base: ptr,
                    offset: Offset32::new(current_length_offset),
                    global_type: pointer_type,
                    flags: ir::MemFlags::trusted(),
                });
                (
                    Uimm64::new(offset_guard_size),
                    HeapStyle::Dynamic {
                        bound_gv: heap_bound,
                    },
                    false,
                )
            }
            MemoryStyle::Static {
                bound,
                offset_guard_size,
            } => (
                Uimm64::new(offset_guard_size),
                HeapStyle::Static {
                    bound: bound.bytes().0 as u64,
                },
                true,
            ),
        };

        let heap_base = func.create_global_value(ir::GlobalValueData::Load {
            base: ptr,
            offset: Offset32::new(base_offset),
            global_type: pointer_type,
            flags: if readonly_base {
                ir::MemFlags::trusted().with_readonly()
            } else {
                ir::MemFlags::trusted()
            },
        });
        Ok(self.heaps.push(HeapData {
            base: heap_base,
            min_size: 0,
            max_size: None,
            memory_type: None,
            offset_guard_size: offset_guard_size.into(),
            style: heap_style,
            index_type: I32,
            page_size_log2: self.target_config.page_size_align_log2,
        }))
    }

    fn make_global(
        &mut self,
        func: &mut ir::Function,
        index: GlobalIndex,
    ) -> WasmResult<GlobalVariable> {
        let pointer_type = self.pointer_type();

        let (ptr, offset) = {
            let vmctx = self.vmctx(func);

            let from_offset = if let Some(def_index) = self.module.local_global_index(index) {
                self.offsets.vmctx_vmglobal_definition(def_index)
            } else {
                self.offsets.vmctx_vmglobal_import_definition(index)
            };

            let global = func.create_global_value(ir::GlobalValueData::Load {
                base: vmctx,
                offset: Offset32::new(i32::try_from(from_offset).unwrap()),
                global_type: pointer_type,
                flags: MemFlags::trusted(),
            });

            (global, 0)
        };

        Ok(GlobalVariable::Memory {
            gv: ptr,
            offset: offset.into(),
            ty: match self.module.globals[index].ty {
                WasmerType::I32 => ir::types::I32,
                WasmerType::I64 => ir::types::I64,
                WasmerType::F32 => ir::types::F32,
                WasmerType::F64 => ir::types::F64,
                WasmerType::V128 => ir::types::I8X16,
                WasmerType::FuncRef | WasmerType::ExternRef | WasmerType::ExceptionRef => {
                    self.reference_type()
                }
            },
        })
    }

    fn make_indirect_sig(
        &mut self,
        func: &mut ir::Function,
        index: SignatureIndex,
    ) -> WasmResult<ir::SigRef> {
        Ok(func.import_signature(self.signatures[index].clone()))
    }

    fn make_direct_func(
        &mut self,
        func: &mut ir::Function,
        index: FunctionIndex,
    ) -> WasmResult<ir::FuncRef> {
        let sigidx = self.module.functions[index];
        let signature = func.import_signature(self.signatures[sigidx].clone());
        let name = get_function_name(func, index);

        Ok(func.import_function(ir::ExtFuncData {
            name,
            signature,
            colocated: true,
            patchable: false,
        }))
    }

    fn translate_call_indirect(
        &mut self,
        builder: &mut FunctionBuilder,
        table_index: TableIndex,
        sig_index: SignatureIndex,
        sig_ref: ir::SigRef,
        callee: ir::Value,
        call_args: &[ir::Value],
        landing_pad: Option<LandingPad>,
    ) -> WasmResult<SmallVec<[ir::Value; 4]>> {
        let pointer_type = self.pointer_type();

        // Get the anyfunc pointer (the funcref) from the table.
        let anyfunc_ptr = self.get_or_init_funcref_table_elem(builder, table_index, callee);

        // Dereference table_entry_addr to get the function address.
        let mem_flags = ir::MemFlags::trusted();

        // check if the funcref is null
        builder
            .ins()
            .trapz(anyfunc_ptr, crate::TRAP_INDIRECT_CALL_TO_NULL);

        let func_addr = builder.ins().load(
            pointer_type,
            mem_flags,
            anyfunc_ptr,
            i32::from(self.offsets.vmcaller_checked_anyfunc_func_ptr()),
        );

        // If necessary, check the signature.
        match self.table_styles[table_index] {
            TableStyle::CallerChecksSignature => {
                let sig_id_size = self.offsets.size_of_vmshared_signature_index();
                let sig_id_type = ir::Type::int(u16::from(sig_id_size) * 8).unwrap();
                let vmctx = self.vmctx(builder.func);
                let base = builder.ins().global_value(pointer_type, vmctx);
                let offset =
                    i32::try_from(self.offsets.vmctx_vmshared_signature_id(sig_index)).unwrap();

                // Load the caller ID.
                let mut mem_flags = ir::MemFlags::trusted();
                mem_flags.set_readonly();
                let caller_sig_id = builder.ins().load(sig_id_type, mem_flags, base, offset);

                // Load the callee ID.
                let mem_flags = ir::MemFlags::trusted();
                let callee_sig_id = builder.ins().load(
                    sig_id_type,
                    mem_flags,
                    anyfunc_ptr,
                    i32::from(self.offsets.vmcaller_checked_anyfunc_type_index()),
                );

                // Check that they match.
                let cmp = builder
                    .ins()
                    .icmp(IntCC::Equal, callee_sig_id, caller_sig_id);
                builder.ins().trapz(cmp, crate::TRAP_BAD_SIGNATURE);
            }
        }

        let mut real_call_args = Vec::with_capacity(call_args.len() + 2);

        // First append the callee vmctx address.
        let vmctx = builder.ins().load(
            pointer_type,
            mem_flags,
            anyfunc_ptr,
            i32::from(self.offsets.vmcaller_checked_anyfunc_vmctx()),
        );
        real_call_args.push(vmctx);

        // Then append the regular call arguments.
        real_call_args.extend_from_slice(call_args);

        let results = self.call_indirect_with_handlers(
            builder,
            sig_ref,
            func_addr,
            &real_call_args,
            Some(vmctx),
            landing_pad,
            false,
        );
        Ok(results)
    }

    fn translate_call(
        &mut self,
        builder: &mut FunctionBuilder,
        callee_index: FunctionIndex,
        callee: ir::FuncRef,
        call_args: &[ir::Value],
        landing_pad: Option<LandingPad>,
    ) -> WasmResult<SmallVec<[ir::Value; 4]>> {
        let mut real_call_args = Vec::with_capacity(call_args.len() + 2);

        // Handle direct calls to locally-defined functions.
        if !self.module.is_imported_function(callee_index) {
            // Let's get the caller vmctx
            let caller_vmctx = builder
                .func
                .special_param(ArgumentPurpose::VMContext)
                .unwrap();
            // First append the callee vmctx address, which is the same as the caller vmctx in
            // this case.
            real_call_args.push(caller_vmctx);

            // Then append the regular call arguments.
            real_call_args.extend_from_slice(call_args);

            let results = self.call_with_handlers(
                builder,
                callee,
                &real_call_args,
                Some(caller_vmctx),
                landing_pad,
                false,
            );
            return Ok(results);
        }

        // Handle direct calls to imported functions. We use an indirect call
        // so that we don't have to patch the code at runtime.
        let pointer_type = self.pointer_type();
        let sig_ref = builder.func.dfg.ext_funcs[callee].signature;
        let vmctx = self.vmctx(builder.func);
        let base = builder.ins().global_value(pointer_type, vmctx);

        let mem_flags = ir::MemFlags::trusted();

        // Load the callee address.
        let body_offset =
            i32::try_from(self.offsets.vmctx_vmfunction_import_body(callee_index)).unwrap();
        let func_addr = builder
            .ins()
            .load(pointer_type, mem_flags, base, body_offset);

        // First append the callee vmctx address.
        let vmctx_offset =
            i32::try_from(self.offsets.vmctx_vmfunction_import_vmctx(callee_index)).unwrap();
        let vmctx = builder
            .ins()
            .load(pointer_type, mem_flags, base, vmctx_offset);
        real_call_args.push(vmctx);

        // Then append the regular call arguments.
        real_call_args.extend_from_slice(call_args);

        let results = self.call_indirect_with_handlers(
            builder,
            sig_ref,
            func_addr,
            &real_call_args,
            Some(vmctx),
            landing_pad,
            false,
        );
        Ok(results)
    }

    fn tag_param_arity(&self, tag_index: TagIndex) -> usize {
        let sig_index = self.module.tags[tag_index];
        let signature = &self.module.signatures[sig_index];
        signature.params().len()
    }

    fn translate_exn_pointer_to_ref(
        &mut self,
        builder: &mut FunctionBuilder,
        exn_ptr: ir::Value,
    ) -> ir::Value {
        let (read_sig, read_idx) = self.get_read_exception_func(builder.func);
        let mut pos = builder.cursor();
        let (_, read_addr) = self.translate_load_builtin_function_address(&mut pos, read_idx);
        let read_call = builder.ins().call_indirect(read_sig, read_addr, &[exn_ptr]);
        builder.inst_results(read_call)[0]
    }

    fn translate_exn_unbox(
        &mut self,
        builder: &mut FunctionBuilder,
        tag_index: TagIndex,
        exnref: ir::Value,
    ) -> WasmResult<SmallVec<[ir::Value; 4]>> {
        let layout = self.exception_type_layout(tag_index)?.clone();

        let (read_exnref_sig, read_exnref_idx) = self.get_read_exnref_func(builder.func);
        let mut pos = builder.cursor();
        let (vmctx, read_exnref_addr) =
            self.translate_load_builtin_function_address(&mut pos, read_exnref_idx);
        let read_exnref_call =
            builder
                .ins()
                .call_indirect(read_exnref_sig, read_exnref_addr, &[vmctx, exnref]);
        let payload_ptr = builder.inst_results(read_exnref_call)[0];

        let mut values = SmallVec::<[ir::Value; 4]>::with_capacity(layout.fields.len());
        let data_flags = ir::MemFlags::trusted();
        for field in &layout.fields {
            let value = builder.ins().load(
                field.ty,
                data_flags,
                payload_ptr,
                Offset32::new(field.offset as i32),
            );
            values.push(value);
        }

        Ok(values)
    }

    fn translate_exn_throw(
        &mut self,
        builder: &mut FunctionBuilder,
        tag_index: TagIndex,
        args: &[ir::Value],
        landing_pad: Option<LandingPad>,
    ) -> WasmResult<()> {
        let layout = self.exception_type_layout(tag_index)?.clone();
        if layout.fields.len() != args.len() {
            return Err(WasmError::Generic(format!(
                "exception payload arity mismatch: expected {}, got {}",
                layout.fields.len(),
                args.len()
            )));
        }

        let (alloc_sig, alloc_idx) = self.get_alloc_exception_func(builder.func);
        let mut pos = builder.cursor();
        let (vmctx, alloc_addr) = self.translate_load_builtin_function_address(&mut pos, alloc_idx);
        let tag_value = builder
            .ins()
            .iconst(TAG_TYPE, i64::from(tag_index.as_u32()));
        let alloc_call = builder
            .ins()
            .call_indirect(alloc_sig, alloc_addr, &[vmctx, tag_value]);
        let exnref = builder.inst_results(alloc_call)[0];

        let (read_exnref_sig, read_exnref_idx) = self.get_read_exnref_func(builder.func);
        let mut pos = builder.cursor();
        let (vmctx, read_exnref_addr) =
            self.translate_load_builtin_function_address(&mut pos, read_exnref_idx);
        let read_exnref_call =
            builder
                .ins()
                .call_indirect(read_exnref_sig, read_exnref_addr, &[vmctx, exnref]);
        let payload_ptr = builder.inst_results(read_exnref_call)[0];

        let store_flags = ir::MemFlags::trusted();
        for (field, value) in layout.fields.iter().zip(args.iter()) {
            debug_assert_eq!(
                builder.func.dfg.value_type(*value),
                field.ty,
                "exception payload type mismatch"
            );
            builder.ins().store(
                store_flags,
                *value,
                payload_ptr,
                Offset32::new(field.offset as i32),
            );
        }

        let (throw_sig, throw_idx) = self.get_throw_func(builder.func);
        let mut pos = builder.cursor();
        let (vmctx_value, throw_addr) =
            self.translate_load_builtin_function_address(&mut pos, throw_idx);
        let call_args = [vmctx_value, exnref];

        let _ = self.call_indirect_with_handlers(
            builder,
            throw_sig,
            throw_addr,
            &call_args,
            Some(vmctx_value),
            landing_pad,
            true,
        );

        Ok(())
    }

    fn translate_exn_throw_ref(
        &mut self,
        builder: &mut FunctionBuilder,
        exnref: ir::Value,
        landing_pad: Option<LandingPad>,
    ) -> WasmResult<()> {
        let (throw_sig, throw_idx) = self.get_throw_func(builder.func);
        let mut pos = builder.cursor();
        let (vmctx_value, throw_addr) =
            self.translate_load_builtin_function_address(&mut pos, throw_idx);
        let call_args = [vmctx_value, exnref];

        let _ = self.call_indirect_with_handlers(
            builder,
            throw_sig,
            throw_addr,
            &call_args,
            Some(vmctx_value),
            landing_pad,
            true,
        );

        Ok(())
    }

    fn translate_exn_personality_selector(
        &mut self,
        builder: &mut FunctionBuilder,
        exn_ptr: ir::Value,
    ) -> WasmResult<ir::Value> {
        let (sig, idx) = self.get_personality2_func(builder.func);
        let pointer_type = self.pointer_type();
        let exn_ty = builder.func.dfg.value_type(exn_ptr);
        let exn_arg = if exn_ty == pointer_type {
            exn_ptr
        } else {
            let mut flags = MemFlags::new();
            flags.set_endianness(Endianness::Little);
            builder.ins().bitcast(pointer_type, flags, exn_ptr)
        };

        let mut pos = builder.cursor();
        let (vmctx_value, func_addr) = self.translate_load_builtin_function_address(&mut pos, idx);
        let call = builder
            .ins()
            .call_indirect(sig, func_addr, &[vmctx_value, exn_arg]);
        Ok(builder.inst_results(call)[0])
    }

    fn translate_exn_reraise_unmatched(
        &mut self,
        builder: &mut FunctionBuilder,
        exnref: ir::Value,
    ) -> WasmResult<()> {
        let (throw_sig, throw_idx) = self.get_throw_func(builder.func);
        let mut pos = builder.cursor();
        let (vmctx_value, throw_addr) =
            self.translate_load_builtin_function_address(&mut pos, throw_idx);
        builder
            .ins()
            .call_indirect(throw_sig, throw_addr, &[vmctx_value, exnref]);
        builder.ins().trap(crate::TRAP_UNREACHABLE);
        Ok(())
    }

    fn translate_memory_grow(
        &mut self,
        mut pos: FuncCursor<'_>,
        index: MemoryIndex,
        _heap: Heap,
        val: ir::Value,
    ) -> WasmResult<ir::Value> {
        let (func_sig, index_arg, func_idx) = self.get_memory_grow_func(pos.func, index);
        let memory_index = pos.ins().iconst(I32, index_arg as i64);
        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);
        let call_inst = pos
            .ins()
            .call_indirect(func_sig, func_addr, &[vmctx, val, memory_index]);
        Ok(*pos.func.dfg.inst_results(call_inst).first().unwrap())
    }

    fn translate_memory_size(
        &mut self,
        mut pos: FuncCursor<'_>,
        index: MemoryIndex,
        _heap: Heap,
    ) -> WasmResult<ir::Value> {
        let (func_sig, index_arg, func_idx) = self.get_memory_size_func(pos.func, index);
        let memory_index = pos.ins().iconst(I32, index_arg as i64);
        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);
        let call_inst = pos
            .ins()
            .call_indirect(func_sig, func_addr, &[vmctx, memory_index]);
        Ok(*pos.func.dfg.inst_results(call_inst).first().unwrap())
    }

    fn translate_memory_copy(
        &mut self,
        mut pos: FuncCursor,
        src_index: MemoryIndex,
        _src_heap: Heap,
        _dst_index: MemoryIndex,
        _dst_heap: Heap,
        dst: ir::Value,
        src: ir::Value,
        len: ir::Value,
    ) -> WasmResult<()> {
        let (func_sig, src_index, func_idx) = self.get_memory_copy_func(pos.func, src_index);

        let src_index_arg = pos.ins().iconst(I32, src_index as i64);

        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);

        pos.ins()
            .call_indirect(func_sig, func_addr, &[vmctx, src_index_arg, dst, src, len]);

        Ok(())
    }

    fn translate_memory_fill(
        &mut self,
        mut pos: FuncCursor,
        memory_index: MemoryIndex,
        _heap: Heap,
        dst: ir::Value,
        val: ir::Value,
        len: ir::Value,
    ) -> WasmResult<()> {
        let (func_sig, memory_index, func_idx) = self.get_memory_fill_func(pos.func, memory_index);

        let memory_index_arg = pos.ins().iconst(I32, memory_index as i64);

        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);

        pos.ins().call_indirect(
            func_sig,
            func_addr,
            &[vmctx, memory_index_arg, dst, val, len],
        );

        Ok(())
    }

    fn translate_memory_init(
        &mut self,
        mut pos: FuncCursor,
        memory_index: MemoryIndex,
        _heap: Heap,
        seg_index: u32,
        dst: ir::Value,
        src: ir::Value,
        len: ir::Value,
    ) -> WasmResult<()> {
        let (func_sig, func_idx) = self.get_memory_init_func(pos.func);

        let memory_index_arg = pos.ins().iconst(I32, memory_index.index() as i64);
        let seg_index_arg = pos.ins().iconst(I32, seg_index as i64);

        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);

        pos.ins().call_indirect(
            func_sig,
            func_addr,
            &[vmctx, memory_index_arg, seg_index_arg, dst, src, len],
        );

        Ok(())
    }

    fn translate_data_drop(&mut self, mut pos: FuncCursor, seg_index: u32) -> WasmResult<()> {
        let (func_sig, func_idx) = self.get_data_drop_func(pos.func);
        let seg_index_arg = pos.ins().iconst(I32, seg_index as i64);
        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);
        pos.ins()
            .call_indirect(func_sig, func_addr, &[vmctx, seg_index_arg]);
        Ok(())
    }

    fn translate_table_size(
        &mut self,
        mut pos: FuncCursor,
        table_index: TableIndex,
    ) -> WasmResult<ir::Value> {
        self.ensure_table_exists(pos.func, table_index);
        let (func_sig, index_arg, func_idx) = self.get_table_size_func(pos.func, table_index);
        let table_index = pos.ins().iconst(I32, index_arg as i64);
        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);
        let call_inst = pos
            .ins()
            .call_indirect(func_sig, func_addr, &[vmctx, table_index]);
        Ok(*pos.func.dfg.inst_results(call_inst).first().unwrap())
    }

    fn translate_table_copy(
        &mut self,
        mut pos: FuncCursor,
        dst_table_index: TableIndex,
        src_table_index: TableIndex,
        dst: ir::Value,
        src: ir::Value,
        len: ir::Value,
    ) -> WasmResult<()> {
        self.ensure_table_exists(pos.func, src_table_index);
        self.ensure_table_exists(pos.func, dst_table_index);
        let (func_sig, dst_table_index_arg, src_table_index_arg, func_idx) =
            self.get_table_copy_func(pos.func, dst_table_index, src_table_index);

        let dst_table_index_arg = pos.ins().iconst(I32, dst_table_index_arg as i64);
        let src_table_index_arg = pos.ins().iconst(I32, src_table_index_arg as i64);

        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);

        pos.ins().call_indirect(
            func_sig,
            func_addr,
            &[
                vmctx,
                dst_table_index_arg,
                src_table_index_arg,
                dst,
                src,
                len,
            ],
        );

        Ok(())
    }

    fn translate_table_init(
        &mut self,
        mut pos: FuncCursor,
        seg_index: u32,
        table_index: TableIndex,
        dst: ir::Value,
        src: ir::Value,
        len: ir::Value,
    ) -> WasmResult<()> {
        self.ensure_table_exists(pos.func, table_index);
        let (func_sig, table_index_arg, func_idx) = self.get_table_init_func(pos.func, table_index);

        let table_index_arg = pos.ins().iconst(I32, table_index_arg as i64);
        let seg_index_arg = pos.ins().iconst(I32, seg_index as i64);

        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);

        pos.ins().call_indirect(
            func_sig,
            func_addr,
            &[vmctx, table_index_arg, seg_index_arg, dst, src, len],
        );

        Ok(())
    }

    fn translate_elem_drop(&mut self, mut pos: FuncCursor, elem_index: u32) -> WasmResult<()> {
        let (func_sig, func_idx) = self.get_elem_drop_func(pos.func);

        let elem_index_arg = pos.ins().iconst(I32, elem_index as i64);

        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);

        pos.ins()
            .call_indirect(func_sig, func_addr, &[vmctx, elem_index_arg]);

        Ok(())
    }

    fn translate_atomic_wait(
        &mut self,
        mut pos: FuncCursor,
        index: MemoryIndex,
        _heap: Heap,
        addr: ir::Value,
        expected: ir::Value,
        timeout: ir::Value,
    ) -> WasmResult<ir::Value> {
        let (func_sig, index_arg, func_idx) = if pos.func.dfg.value_type(expected) == I64 {
            self.get_memory_atomic_wait64_func(pos.func, index)
        } else {
            self.get_memory_atomic_wait32_func(pos.func, index)
        };
        let memory_index = pos.ins().iconst(I32, index_arg as i64);
        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);
        let call_inst = pos.ins().call_indirect(
            func_sig,
            func_addr,
            &[vmctx, memory_index, addr, expected, timeout],
        );
        Ok(*pos.func.dfg.inst_results(call_inst).first().unwrap())
    }

    fn translate_atomic_notify(
        &mut self,
        mut pos: FuncCursor,
        index: MemoryIndex,
        _heap: Heap,
        addr: ir::Value,
        count: ir::Value,
    ) -> WasmResult<ir::Value> {
        let (func_sig, index_arg, func_idx) = self.get_memory_atomic_notify_func(pos.func, index);
        let memory_index = pos.ins().iconst(I32, index_arg as i64);
        let (vmctx, func_addr) = self.translate_load_builtin_function_address(&mut pos, func_idx);
        let call_inst =
            pos.ins()
                .call_indirect(func_sig, func_addr, &[vmctx, memory_index, addr, count]);
        Ok(*pos.func.dfg.inst_results(call_inst).first().unwrap())
    }

    fn get_global_type(&self, global_index: GlobalIndex) -> Option<WasmerType> {
        Some(self.module.globals.get(global_index)?.ty)
    }

    fn push_local_decl_on_stack(&mut self, ty: WasmerType) {
        self.type_stack.push(ty);
    }

    fn push_params_on_stack(&mut self, function_index: LocalFunctionIndex) {
        let func_index = self.module.func_index(function_index);
        let sig_idx = self.module.functions[func_index];
        let signature = &self.module.signatures[sig_idx];
        for param in signature.params() {
            self.type_stack.push(*param);
        }
    }

    fn get_local_type(&self, local_index: u32) -> Option<WasmerType> {
        self.type_stack.get(local_index as usize).cloned()
    }

    fn get_local_types(&self) -> &[WasmerType] {
        &self.type_stack
    }

    fn get_function_type(&self, function_index: FunctionIndex) -> Option<&FunctionType> {
        let sig_idx = self.module.functions.get(function_index)?;
        Some(&self.module.signatures[*sig_idx])
    }

    fn get_function_sig(&self, sig_index: SignatureIndex) -> Option<&FunctionType> {
        self.module.signatures.get(sig_index)
    }

    fn heap_access_spectre_mitigation(&self) -> bool {
        false
    }

    fn proof_carrying_code(&self) -> bool {
        false
    }

    fn heaps(&self) -> &PrimaryMap<Heap, HeapData> {
        &self.heaps
    }
}