[Info-vax] xcc long double implementation

[David Jones]

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.

SQLite doesn't seem to be consistent across platforms. the SQL statement:

    SELECT CAST(9223372036854774800 AS real);

gives slightly different results on my Intel Mac (9.22337203685477e+18) and my Arm-based Pi4
(9.22337203685478e+18). That's the same discrepancy I see between my Alpha/IA64 and X86
builds on OpenVMS. Note that the i64 value being converted has more the 15 significant
decimal digits, the the '4800' is getting rounded up on platforms that don't have long double.