fusion_planner.h File Reference

Identifies maximal fusion-legality domains in a finalized DAG. More...

#include "stage/fusion.h"
#include <cstdint>
#include <string>
#include <vector>

Go to the source code of this file.

Classes
struct	fz::FusionGeometry
	Geometry accumulated while extending one candidate fusion chain. More...
struct	fz::FusionGroup
	One maximal fusion-legality domain, in producer→consumer order. More...

Namespaces
namespace	fz

Enumerations
enum class	fz::FusionCompatibility : uint8_t
	Exact reason a stage spec cannot extend an accumulated group geometry.

Functions
FusionCompatibility	fz::extendFusionGeometry (FusionGeometry &geometry, const FusionSpec &next)
	Validate and, on success, extend geometry with next.
std::vector< FusionGroup >	fz::planFusionGroups (const CompressionDAG &dag)

Detailed Description

Identifies maximal fusion-legality domains in a finalized DAG.

The planner is pure analysis: it walks the compress DAG and returns the linear chains within which fused execution plans may be considered. It does not require one implementation to cover the whole maximal chain: a later pass enumerates contiguous subspans, finds registered/generated implementations, and selects non-overlapping profitable candidates. Unmatched stages keep running staged.

A group is a maximal chain where every stage opts into fusion (Stage::getFusionSpec()), the chain is strictly linear (no fan-in/out inside it), conventional region-local/segment-codec members share one region size, and a SegmentCodec, if present, terminates the chain because it emits variable-length segments. A TileSelector instead owns a larger tile made of equal immediate downstream codec segments. See docs/codebase_notes.md CN-FUSE-PROOF.