(refactor): Build jump and jump table to support prepended instructions.

[eytan-starkware]

Summary

Added extended versions of build_enum_match_short and build_enum_match_long functions that allow prepending instructions. The new functions build_enum_match_short_ex and build_enum_match_long_ex take an additional parameter for initial instructions and properly handle relocation offsets. The original functions were refactored to call these extended versions with empty instruction vectors.

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Type of change

Please check one:

• Bug fix (fixes incorrect behavior)
• New feature
• Performance improvement
• Documentation change with concrete technical impact
• Style, wording, formatting, or typo-only change

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Why is this change needed?

This change enables more flexibility when generating code for enum matching operations by allowing custom instructions to be prepended before the standard matching logic. This is particularly useful for complex enum operations that require setup code before the actual matching logic.

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What was the behavior or documentation before?

Previously, the enum matching functions could only generate a fixed set of instructions without the ability to prepend custom setup instructions.

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What is the behavior or documentation after?

Now, there are extended versions of the enum matching functions that accept an additional parameter for initial instructions. The original functions remain unchanged in behavior but internally call the new extended versions.

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Additional context

The implementation carefully handles relocation offsets to ensure that jump targets remain correct when instructions are prepended. This change maintains backward compatibility while providing more flexibility for code generation.

[eytan-starkware]

• (opt): Libfunc for matching on a boxed enum for boxed variants results #9378
• (refactor): Build jump and jump table to support prepended instructions. #9463 👈 (View in Graphite)
• Refactored boxed deconstruct signature code, creating reusable functions #9462
• (test): Adding casm run and trace to e2e tests #9482
• main

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[reviewable-StarkWare]

This change is 

[orizi]

@orizi made 4 comments.
Reviewable status: 0 of 1 files reviewed, 4 unresolved discussions (waiting on @eytan-starkware, @ilyalesokhin-starkware, and @TomerStarkware).

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crates/cairo-lang-sierra-to-casm/src/invocations/enm.rs line 234 at r1 (raw file):

    >,
) -> Result<CompiledInvocation, InvocationError> {
    build_enum_match_short_ex(builder, variant_selector, output_expressions, vec![])

Suggestion:

    build_enum_match_short_ex(builder, variant_selector, output_expressions, Vec::with_capacity(1))

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crates/cairo-lang-sierra-to-casm/src/invocations/enm.rs line 247 at r1 (raw file):

) -> Result<CompiledInvocation, InvocationError> {
    let mut relocations = Vec::new();
    let relocation_offset = instructions.len();

Suggestion:

    let base_instruction_count = instructions.len();

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crates/cairo-lang-sierra-to-casm/src/invocations/enm.rs line 301 at r1 (raw file):

    >,
) -> Result<CompiledInvocation, InvocationError> {
    build_enum_match_long_ex(builder, variant_selector, output_expressions, vec![])

Suggestion:

    build_enum_match_long_ex(builder, variant_selector, output_expressions, , Vec::with_capacity(builder.invocation.branches.len() + 1))

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crates/cairo-lang-sierra-to-casm/src/invocations/enm.rs line 318 at r1 (raw file):

    });

    let relocation_offset = instructions.len();

Suggestion:

    let base_instruction_count = instructions.len();

[eytan-starkware]

@eytan-starkware made 4 comments.
Reviewable status: 0 of 1 files reviewed, 4 unresolved discussions (waiting on @ilyalesokhin-starkware, @orizi, and @TomerStarkware).

---

crates/cairo-lang-sierra-to-casm/src/invocations/enm.rs line 234 at r1 (raw file):

    >,
) -> Result<CompiledInvocation, InvocationError> {
    build_enum_match_short_ex(builder, variant_selector, output_expressions, vec![])

Done.

---

crates/cairo-lang-sierra-to-casm/src/invocations/enm.rs line 247 at r1 (raw file):

) -> Result<CompiledInvocation, InvocationError> {
    let mut relocations = Vec::new();
    let relocation_offset = instructions.len();

Done.

---

crates/cairo-lang-sierra-to-casm/src/invocations/enm.rs line 301 at r1 (raw file):

    >,
) -> Result<CompiledInvocation, InvocationError> {
    build_enum_match_long_ex(builder, variant_selector, output_expressions, vec![])

Done.

---

crates/cairo-lang-sierra-to-casm/src/invocations/enm.rs line 318 at r1 (raw file):

    });

    let relocation_offset = instructions.len();

Done.

[TomerStarkware]

@TomerStarkware partially reviewed 1 file and made 1 comment.
Reviewable status: all files reviewed (commit messages unreviewed), 4 unresolved discussions (waiting on @ilyalesokhin-starkware and @orizi).

[orizi]

@orizi reviewed 1 file and all commit messages, made 1 comment, and resolved 4 discussions.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @ilyalesokhin-starkware).