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Mojo struct

EdgeRule

struct EdgeRule

Declarative edge derivation rule.

Each rule describes a class of dependency edges: for every (producer, consumer) pair whose OpDesc fields satisfy the predicates, emit a DepEdge with the given kind and loop distance.

The evaluator (apply_edge_rules) pre-classifies ops by role, then for each rule scans only relevant (producer_role, consumer_role) pairs and checks the predicate fields. This replaces the hand-coded 4-phase double-buffer logic and 8-rule single-buffer logic in derive_edges_from_ops with inspectable data.

Fields fall into five groups:

1. Core: producer/consumer roles, dependency kind, loop distance. loop_distance = -1 means "derive from producer.k_offset": K_PREV → d=0 (current-iteration load), otherwise d=1 (prefetch).

2. Field matching: require same channel / stage / subtile between the producer and consumer ops. use_config_match activates the PipelineConfig.compute_match_key() logic (Phase 1 register-FLOW).

3. Half predicates (double-buffer): same_half / cross_half / producer_half constrain which half each op lives in.

4. K-offset filter: 0=any, 1=K_PREV only, 2=non-K_PREV only. Applied to the consumer for LDS-ANTI rules, to the producer for LDS-FLOW distance derivation.

5. Single-buffer predicates: lc_producer/lc_consumer (loop- carried status), producer_ordinal/consumer_ordinal (Nth op of that role), first_match_only (break after first consumer match).

Fields

• ​producer_role (OpRole): Producer op role for this rule.
• ​consumer_role (OpRole): Consumer op role for this rule.
• ​dep_kind (DepKind): Dependency kind (FLOW, ANTI, or OUTPUT).
• ​loop_distance (Int): Loop iterations between producer and consumer (0, 1, or -1). -1 derives from producer.k_offset: K_PREV → d=0 (current-iteration load), otherwise d=1 (prefetch).
• ​match_channel (Bool): Require the producer and consumer to share the same channel.
• ​match_stage (Bool): Require the producer and consumer to share the same stage.
• ​match_subtile (Bool): Require the producer and consumer to share the same subtile.
• ​use_config_match (Bool): Use PipelineConfig.compute_match_key() (Phase 1 register-FLOW).
• ​same_half (Bool): Require both ops to live in the same half.
• ​cross_half (Bool): Require the ops to live in different halves.
• ​producer_half (Int): Producer half filter (-1 = any, 0 = first half, 1 = second half).
• ​k_offset_filter (Int): K-offset filter (0 = any, 1 = K_PREV only, 2 = non-K_PREV only). Applied to the consumer for LDS-ANTI rules and to the producer for LDS-FLOW distance derivation.
• ​lc_producer (Int): Loop-carried filter for the producer (-1 = any, 0 = non-lc, 1 = lc).
• ​lc_consumer (Int): Loop-carried filter for the consumer (-1 = any, 0 = non-lc, 1 = lc).
• ​producer_ordinal (Int): Producer ordinal filter (-1 = any, N = Nth occurrence of producer_role).
• ​consumer_ordinal (Int): Consumer ordinal filter (-1 = any, N = Nth occurrence of consumer_role).
• ​first_match_only (Bool): Break after the first consumer match per producer.

Implemented traits

AnyType, Copyable, ImplicitlyCopyable, ImplicitlyDeletable, Movable