of space, making it a redundant encoding. this just leaves the
purpose of `pfishmv` to be to extend (fill) an FP32 out to an FP64.
+that said: the next phase of whether it is worthwhile is to count the
+I/D-Cache usage.
the analysis counting instructions and D-Cache Loads actually shows
that whilst the initial idea for `pfishmv` would be to fill in the
remaining mantissa and high exponent bits to complete a full FP64,