[M3devel] files larger than 2gig

[Jay]

The NT386 backend internally uses a stack of 32bit words to slightly optimize codegen..it seems kind of similar to what the frontend does..I wonder if it is redundant..
Anyway..
It doesn't appear easy to extend, but with years of hindsight at this point..it might be easiest to have a mode where the front end decomposes 64bit operations into multiple 32bit operations.
Maybe that'd be an entire "cg layer" (it appears code generators are layerable).
 
 
I'm less keen on the LONGREAL solution but still pretty keen on LONGINT.
Not right now though, maybe in a few days..
 
 
 - Jay


----------------------------------------
> Date: Mon, 22 Jun 2009 16:30:03 +0200
> From: wagner at elegosoft.com
> To: m3devel at elegosoft.com
> Subject: Re: [M3devel] files larger than 2gig
>
> Quoting Jay :
>
>>
>> C:\dev2\cm3.2\m3-libs\libm3\src\os\Common\File.i3
>>
>>
>> TYPE
>> Status = RECORD
>> type: Type;
>> modificationTime: Time.T;
>> size: INTEGER;
>> END;
>>
>>
>> size: INTEGER causes exceptions when you use the Modula-3 gui
>> and browse to a directory with files larger than 2 gig.
>
> This is a known limitation on all 32 bit platforms.
>
>> I suggest size be changed to LONGREAL, which generally has a 53 bit mantissa
>> (out 64 bits total) and thus can represent integers very much larger
>> than INTEGER.
>
> I wouldn't like that. Sizes are no real numbers, really ;-)
> Either use LONGINT or rely on INTEGER being large enough (64 bit
> on all 64 bit targets).
>
>> LONGINT is a tempting option but doesn't help on the current NT386 platform,
>> and I think 53 bits will last a very long time.
>
> What exactly was the problem in makeing LONGINT work on NT386?
>
>> I'm just trying out such a change and I can see it is not source compatible:
>>
>>
>> "../src/rw/FileRd.m3", line 73: incompatible argument types: MIN
>> "../src/rw/FileRd.m3", line 140: types are not assignable
>> 2 errors encountered
>> "../src/rw/FileWr.m3", line 87: incompatible argument types: MIN
>> "../src/rw/FileWr.m3", line 103: incompatible argument types: MAX
>> 2 errors encountered
>>
>>
>> Nevertheless I think it should be done, probably even for this release.
>
> I'm not convinced...
>
> Olaf
> --
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