spl_fixpt_recip
spl_scratch->scl_data.recip_ratios.horz = spl_fixpt_recip(
spl_scratch->scl_data.recip_ratios.vert = spl_fixpt_recip(
spl_scratch->scl_data.recip_ratios.horz_c = spl_fixpt_recip(
spl_scratch->scl_data.recip_ratios.vert_c = spl_fixpt_recip(
struct spl_fixed31_32 spl_fixpt_recip(struct spl_fixed31_32 arg);