[Info-vax] Userland programming languages on VMS.

[Johnny Billquist]

On 2022-01-31 01:43, Arne Vajhøj wrote:
> On 1/30/2022 7:19 PM, Simon Clubley wrote:
>> On 2022-01-29, Arne Vajhøj <arne at vajhoej.dk> wrote:
>>> On 1/29/2022 1:53 AM, George Cornelius wrote:
>>>>
>>>> Works on Eisner.
>>>>
>>>> $ show sys/noproc
>>>> OpenVMS V8.4-2L2  on node EISNER   29-JAN-2022 [...]
>>>>
>>>> Here's the memory layout synopsis from a linker map:
>>>>
>>>> Virtual memory allocated:                         00010000 0005FFFF 
>>>> 00050000 (327680. bytes, 640. pages)
>>>> 64-Bit Virtual memory allocated:                  00000000 00000000 
>>>> 00000000
>>>>                                                     80000000 
>>>> 80010000 00010000 (65536. bytes, 128. pages)
>>>>
>>>> The example, though, shows too small an allocation to escape 32 bit 
>>>> address space.
>>>
>>> I consider 0000000080000000 to be 64 bit space.
>>>
>>> 0000000000000000 - 000000007FFFFFFF is P0 and P1 space
>>> FFFFFFFF80000000 - FFFFFFFFFFFFFFFF is S0 and S1 space
>>> 0000000080000000 and upward is P2 space
>>>
>>
>> I think George's point is that this specific address can be
>> represented in a 32-bit pointer.
> 
> It can't.
> 
> A 32 bit pointer with the value 80000000 will end up as
> FFFFFFFF80000000.

Since when are pointers considered to be signed and need sign extension?

   Johnny