kernel.subgroup.scan

← kernel dialect

Prefix-scan a scalar or rank-1 vector value across the current subgroup.

Operation contract

Property	Value
Semantic phase	executable
Traits	Convergent, HasAncestor(kernel.def)
Target contracts	kernel.synchronization

Signature

Kind	Name	Type	Cardinality	Description
Operand	value	any	required	Per-invocation value to scan.
Result	result	any	required	Scanned value.
Attribute	kind	enum CombiningKind	required	Combining operation.
Attribute	cluster_size	i64	optional	Optional clustered subgroup size.
Attribute	cluster_stride	i64	optional	Optional clustered subgroup stride.
Attribute	mode	enum KernelScanMode	required	Inclusive or exclusive scan.
Attribute	direction	enum KernelScanDirection	required	Lane order to scan.

Verification constraints

• SameType(value, result)

Examples

%prefix = kernel.subgroup.scan<addf> %v {mode = inclusive, direction = forward} : f32