[Info-vax] VMS Software Q1 '23 Update

[Arne Vajhøj]

On 1/30/2023 9:50 PM, Craig A. Berry wrote:
> On 1/30/23 6:32 PM, Arne Vajhøj wrote:
>> I wonder what Basic on Itanium does and what Basic on x86-64 does / 
>> will do.
>>
>> Convert to T and do T math? Or software emulation?
> 
> Looks like for Itanium it's all covered here:
> 
> http://neilrieck.net/misc/pdf/vms-docs/i64-floating-pt-wp.pdf
> 
> It seems unlikely they would do anything differently for x86_64.

<quote>
When you compile an OpenVMS application that specifies an option to use VAX
floating-point on the Itanium architecture, the compiler automatically 
generates code for
converting floating-point formats. Whenever the application performs a 
sequence of
arithmetic operations, this code does the following:
1. Converts VAX floating-point formats to either IEEE single or IEEE double
floating-point formats.
2. Performs arithmetic operations in IEEE floating-point arithmetic.
3. Converts the resulting data from IEEE formats back to VAX formats.
</quote>

Arne