[Info-vax] VAX VMS going forward

[Arne Vajhøj]

On 7/28/2020 8:31 AM, Simon Clubley wrote:
> On 2020-07-27, Arne Vajhøj <arne at vajhoej.dk> wrote:
>> On 7/27/2020 8:47 AM, Simon Clubley wrote:
>>>
>>> John, this is why the current setup is not a flat 64-bit implementation
>>> but is a hybrid of 32-bit and 64-bit modes.
>>
>> It is not a 32 mode and a 64 bit mode.
>>
>> The CPU always use 64 bit addresses.
>>
>> A program is not running in any mode.
>>
>> It is API's that can use either 64 bit addresses or 32 bit "compressed"
>> addresses (by only passing the lower part and assuming high bits
>> are all 0).
>>
>> In many ways that is way harder to fix than 32 and 64 bit mode.
> 
> Only on VMS. This is (mostly) not a significant problem on other
> operating systems because the vast majority of the work is done for
> you by the compiler and linker in those environments after you tell
> the compiler whether you want your code to run with 32-bit or 64-bit
> addresses and other features.

????

On what other platform is it common to pass 64 bit addresses
as 32 bit bit values with implicit values for the remaining bits?

Arne