[Info-vax] xcc long double implementation

[John Reagan]

On Sunday, September 5, 2021 at 8:43:59 AM UTC-4, osuv... at gmail.com wrote:
> On Friday, September 3, 2021 at 6:16:06 PM UTC-4, xyzz... at gmail.com wrote: 
> > LLVM 3.4.2 only supports the 10-byte/80-bit hardware floating point. However, we want a 16-byte/128-bit floating type (IEEE X_float). 
> >
> Yeah, I figured you'd want that for consistency with the other OpenVMS platforms. I notice LIBOTS.EXE on X86 
> doesn't have OTS$CVTQX() and related functions. 
> 

Yes, both for sharing of binary data and alignment of structures.

For f128, current LLVM calls routines in the LLVM-provided 'compiler-rt' library.  It is LLVM's equivalent of LIBOTS with a bunch of compiler support routines for code sequences too large to put inline.  The f128 routines in compiler-rt have the same names and API as the ones that gcc calls for their f128 support.  At this point, I'm leaning on putting those compiler-rt routines into LIBOTS but haven't make my mind up yet.