Refactored const-folding.

[orizi]

Stack:

• Added mul const folding. #6085
• Refactored range-testing in const folding. #6084
• Added const-folding for u*_overflowing_{add,sub}. #6083
• Added const-folding for the downcast libfunc. #6071
• Refactored const-folding. #6070 ⬅

⚠️ Part of a stack created by spr. Do not merge manually using the UI - doing so may have unexpected results.

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This change is 

[gilbens-starkware]

Reviewed 1 of 1 files at r1, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @orizi)

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crates/cairo-lang-lowering/src/optimizations/const_folding.rs line 179 at r1 (raw file):

    nz_fns: UnorderedHashSet<FunctionId>,
    /// The storage access module.
    storage_access_module: ModuleHelper<'a>,

Consider making these a sub-struct.

Code quote:

    // The required ids for optimizations.
    /// The `felt252_sub` libfunc.
    felt_sub: FunctionId,
    /// The `into_box` libfunc.
    into_box: ExternFunctionId,
    /// The `upcast` libfunc.
    upcast: ExternFunctionId,
    /// The `storage_base_address_from_felt252` libfunc.
    storage_base_address_from_felt252: FunctionId,
    /// The set of functions that check if a number is zero.
    nz_fns: UnorderedHashSet<FunctionId>,
    /// The storage access module.
    storage_access_module: ModuleHelper<'a>,

[gilbens-starkware]

Reviewed all commit messages.
Reviewable status: 0 of 1 files reviewed, 1 unresolved discussion (waiting on @orizi)

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crates/cairo-lang-lowering/src/optimizations/const_folding.rs line 337 at r2 (raw file):

    /// The storage access module.
    storage_access_module: ModuleHelper<'a>,
}

Maybe it should really be static with once_cell::Lazy?

Code quote:

/// Holds static information about libfuncs required for the optimization.
struct LibfuncInfo<'a> {
    /// The `felt252_sub` libfunc.
    felt_sub: FunctionId,
    /// The `into_box` libfunc.
    into_box: ExternFunctionId,
    /// The `upcast` libfunc.
    upcast: ExternFunctionId,
    /// The `storage_base_address_from_felt252` libfunc.
    storage_base_address_from_felt252: FunctionId,
    /// The set of functions that check if a number is zero.
    nz_fns: UnorderedHashSet<FunctionId>,
    /// The storage access module.
    storage_access_module: ModuleHelper<'a>,
}

[orizi]

Reviewable status: 0 of 1 files reviewed, 1 unresolved discussion (waiting on @gilbens-starkware)

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crates/cairo-lang-lowering/src/optimizations/const_folding.rs line 337 at r2 (raw file):

Previously, gilbens-starkware (Gil Ben-Shachar) wrote…

Maybe it should really be static with once_cell::Lazy?

cannot be - but can become a db query - but will get to it when actually required.

[gilbens-starkware]

Reviewed 1 of 1 files at r2.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @orizi)