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34.1 Constant Operands

If the code emitted for a VOP when an argument is constant is very different than the non-constant case, then it may be desirable to special-case the operation in VMR conversion by emitting different VOPs. An example would be if SVREF is only open-coded when the index is a constant, and turns into a miscop call otherwise. We wouldn’t want constant references to spuriously allocate all the miscop linkage registers on the off chance that the offset might not be constant. See the :constant feature of VOP primitive type restrictions.