low.scf.for

← low dialect

Bounded counted target-low loop with optional loop-carried register state.

Operation contract

Property	Value
Semantic phase	executable
Traits	ImplicitTerminator(low.scf.yield), StorageRelation
Interfaces	LoopLike

Signature

Kind	Name	Type	Cardinality	Description
Operand	lower_bound	register	required	Inclusive lower bound register.
Operand	upper_bound	register	required	Exclusive upper bound register.
Operand	step	register	required	Positive step register.
Operand	iter_args	register	variadic	Initial loop-carried register values.
Operand	unroll_factor	register	optional	Optional dynamic target-domain unroll factor.
Result	results	register	variadic	—
Attribute	unroll_policy	enum LowScfForUnrollPolicy	optional	Optional bare unroll policy for required full unroll.
Region	body	region	required	Loop body. Terminated by low.scf.yield. (single block, terminator low.scf.yield.)

Verification constraints

• SameType(lower_bound, upper_bound)
• SameType(lower_bound, step)
• IterArgsMatchResults(iter_args, results)
• BlockArgsSatisfy(body)
• YieldCountMatchesResults(body, results)
• YieldTypesMatchResults(body, results)

Examples

low.scf.for [%lo to %hi step %step] do(%iv: reg<amdgpu.sgpr x1>) {
  low.scf.yield
}

%result = low.scf.for [%lo to %hi step %step] iter_args(%acc0: reg<amdgpu.vgpr x1>) -> (reg<amdgpu.vgpr x1>) do(%iv: reg<amdgpu.sgpr x1>, %acc: reg<amdgpu.vgpr x1>) {
  low.scf.yield %acc : reg<amdgpu.vgpr x1>
}