go/src/cmd/compile/internal/typebits/typebits.go

// NOTE: The bitmap for a specific type t could be cached in t after
// the first run and then simply copied into bv at the correct offset
// on future calls with the same type t.
func Set(t *types.Type, off int64, bv bitvec.BitVec) { … }

// SetNoCheck is like Set, but do not check for alignment.
func SetNoCheck(t *types.Type, off int64, bv bitvec.BitVec) { … }

func set(t *types.Type, off int64, bv bitvec.BitVec, skip bool) { … }