scf.switch

← scf dialect

Multi-way branch over an index selector. Case keys are sorted unique i64 literals. The default region is mandatory and is selected when the selector does not equal any explicit case key. Every region must terminate with scf.yield matching the switch result tuple.

Operation contract

Property	Value
Semantic phase	source structure
Traits	ImplicitTerminator(scf.yield)
Interfaces	RegionBranch

Signature

Kind	Name	Type	Cardinality	Description
Operand	selector	index	required	—
Result	results	any	variadic	—
Attribute	case_keys	i64_array	required	Sorted unique selector values for explicit switch cases.
Region	default_region	region	required	Executed when no explicit case key matches. Terminated by scf.yield. (single block, terminator scf.yield.)
Region	case_regions	region	variadic	Case regions in the same order as case_keys. Terminated by scf.yield. (single block, terminator scf.yield.)

Examples

scf.switch %selector {
  case 0 {
    scf.yield
  }
  default {
    scf.yield
  }
}

%result = scf.switch %selector -> (f32) {
  case 0 {
    scf.yield %a : f32
  }
  case 1 {
    scf.yield %b : f32
  }
  default {
    scf.yield %fallback : f32
  }
}