(feature): A new libfunc for calculating the pointer to temporary storage using a double call

[eytan-starkware]

TL;DR

Added a new get_temp_ptr libfunc to compute addresses for variables based on type size, with utility segment support for code reuse.

What changed?

• Added a new Sierra libfunc get_temp_ptr<T> that computes the address where a value of type T would be located
• Renamed ConstsInfo to SegmentsInfo and extended it to support utility segments for code reuse
• Implemented the CASM compilation for get_temp_ptr using a shared utility segment
• Added AP change and gas cost information for the new libfunc
• Added the libfunc to the Starknet allowed libfuncs list

[reviewable-StarkWare]

This change is 

[eytan-starkware]

• (feature): A new libfunc for calculating the pointer to temporary storage using a double call #8667 👈 (View in Graphite)
• main

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[orizi]

@orizi reviewed 2 of 14 files at r1, all commit messages.
Reviewable status: 2 of 14 files reviewed, 2 unresolved discussions (waiting on @giladchase and @ilyalesokhin-starkware)

---

crates/cairo-lang-sierra/src/extensions/core.rs line 132 at r1 (raw file):

        Gas(GasLibfunc),
        GasReserve(GasReserveLibfunc),
        GetTempPtr(GetTempPtrLibfunc),

move to under Box.

Code quote:

        GetTempPtr(GetTempPtrLibfunc),

---

crates/cairo-lang-sierra/src/extensions/modules/get_temp_ptr.rs line 1 at r1 (raw file):

//! Libfunc for computing the address of a variable based on type size.

box_from_temp_store
all around probably.

[eytan-starkware]

Reviewable status: 1 of 16 files reviewed, 2 unresolved discussions (waiting on @giladchase, @ilyalesokhin-starkware, and @orizi)

---

crates/cairo-lang-sierra/src/extensions/core.rs line 132 at r1 (raw file):

Previously, orizi wrote…

move to under Box.

Done.

---

crates/cairo-lang-sierra/src/extensions/modules/get_temp_ptr.rs line 1 at r1 (raw file):

Previously, orizi wrote…

box_from_temp_store
all around probably.

Done.

[orizi]

@orizi reviewed 6 of 14 files at r2.
Reviewable status: 7 of 16 files reviewed, 2 unresolved discussions (waiting on @giladchase and @ilyalesokhin-starkware)

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crates/cairo-lang-sierra/src/extensions/modules/boxing.rs line 142 at r2 (raw file):

        // The actual offset is computed in CASM based on type size
        Ok(LibfuncSignature::new_non_branch(
            vec![],

you should have the value as an input.

Code quote:

            vec![],

[giladchase]

Reviewable status: 7 of 16 files reviewed, 2 unresolved discussions (waiting on @eytan-starkware, @ilyalesokhin-starkware, and @orizi)

---

crates/cairo-lang-sierra-to-casm/src/compiler.rs line 376 at r2 (raw file):

                let segment = UtilitySegment { instructions, offset: total_segments_size };
                total_segments_size +=
                    segment.instructions.iter().map(|i| i.body.op_size()).sum::<usize>();

Nonblocking: perhaps this should be a for, side-effects inside map (modifying the external var total_segments_size) can be surprising

Code quote:

            .map(|(id, instructions)| {
                let segment = UtilitySegment { instructions, offset: total_segments_size };
                total_segments_size +=
                    segment.instructions.iter().map(|i| i.body.op_size()).sum::<usize>();

[giladchase]

Reviewable status: 7 of 16 files reviewed, 2 unresolved discussions (waiting on @eytan-starkware, @ilyalesokhin-starkware, and @orizi)

---

crates/cairo-lang-sierra-to-casm/src/compiler.rs line 351 at r2 (raw file):

                Ok(CoreConcreteLibfunc::Box(BoxConcreteLibfunc::FromTempStore(_)))
            )
        });

Might be time to iterate only once on libfunc_ids and match on program_info.registry.get_libfunc(id).unwrap()

Code quote:

        let has_box_from_temp_store = libfunc_ids.into_iter().any(|id| {
            matches!(
                program_info.registry.get_libfunc(id),
                Ok(CoreConcreteLibfunc::Box(BoxConcreteLibfunc::FromTempStore(_)))
            )
        });