Just look at this interesting list for floatting point formats (intended for data interchange):
This is something you should keep in mind
Also consider the additional formats used in
FPUs for x86 and ARM (in discrete instructions)
And vector formats in SSE/AVX and APU/GPU (for OpenCL) as they are now widespread
It would be interesting to have Lua ported to work within an OpenCL engine and then be able to use GPUs and other vector extensions (which are very userful for massive data processing, which for now are still processed in legacy languages like FORTRAN, or proprietary mathematical languages and libraries).
Such work has been done for porting apps written in C, C++, Java, Perl, Python, .Net/CLI... but still not Lua and allow their parallelization. Note that I do not propose here a native parallelization in Lua, something that would be another proposal. ANSI C is just a very limited goal for Lua and it does not ease its safe integration in existing application servers or SQL engines (which could host Lua scriptlets, instead of using only Java or some old specific GL language like PL/SQL), except in specific containers running on separate isolated servers (but with poor/slow interaction, as this also requires them to communicate over some networking API, including REST API with response delays, and this is not acceptable for embedded devices and cause complex security concerns)