endian specificity

[jaykrell]

cm3 does provide interopability of Modula-3 bitfields with C bitfields.

Can we decree that that isn't really guaranteed?
Or at least not on big endian systems?
Or at least not if you build with -boot?

i.e. either little endian always, or -boot implies little endian?

I want "one" bootstrap to be endian neutral,
for the larger target matrix to be covered by fewer/one downloads.

[jaykrell]

I believe how this really ends up is:

• cm3 itself has no bitfields
• m3front writing runtime/GC metadata hardcodes little endian, which is actually neutral
• bitfields actually end up, unchanged, just not used in cm3
• we can add Modula-3/C interop tests, that show bitfield layout remains compatible and endian-specific

Bootstrapping the entire system via endian neutral C++ would depend on if bitfields are used.
Bitfields are kinda nice, as a size optimization.

[barracuda156]

@jaykrell I am interested to build it on PowerPC (Big-endian, of course). Can it be bootstrapped from C/C++, without pre-built binary (which may not exist)?

[jaykrell]

Sorta, but it has always been difficult to explain.
Well, er, not sure we have big endian bootstraps, but we ought too.. I'll check..

[jaykrell]

I see only little endian, or 64bit big endian bootstraps.
I had a goal to make more portable bootstraps (endian independent, word size independent), but it is quite stalled, sorry.
It is pretty easy though, if you have any other system, to cross build the 32big bit endian bootstrap. I don't know if we ever got PPC64_DARWIN working..shouldn't be difficult..we have so many others..

[barracuda156]

@jaykrell If there exists a procedure to build it starting from gcc without pre-built cm3 binary, that will be preferable. I wanna make a port for Macports, and using cross-compilation for that purpose it not a workable option.

Modula2 builds fine on Darwin ppc – within gcc, starting with nothing. There should be something similar here?

[mikanystrom]

I used to use cm3 on macppc.. long ago! But I'm sure the code is still in there. But it required bootstrapping.

…

On Mon, Oct 16, 2023, 1:46 AM Sergey Fedorov ***@***.***> wrote: @jaykrell <https://github.com/jaykrell> If there exists a procedure to build it starting from gcc without pre-built cm3 binary, that will be preferable. I wanna make a port for Macports, and using cross-compilation for that purpose it not a workable option. Modula2 builds fine on Darwin ppc – within gcc, starting with nothing. There should be something similar here? — Reply to this email directly, view it on GitHub <#995 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABKYNJKX2S6YAHVPED5PGTTX7TX6NAVCNFSM5N72L7CKU5DIOJSWCZC7NNSXTN2JONZXKZKDN5WW2ZLOOQ5TCNZWGQYDAOJZHAYA> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[barracuda156]

@mikanystrom Do I need anything besides gcc for that? I.e. some archaic pre-built bootstrap binaries of cm3, or not?

[VictorMiasnikov]

( . . .) If there exists a procedure to build it starting from gcc without pre-built cm3 binary, that will be preferable.

You can try this:

1. cm3-d5.11.9-ZZYYXX-20230928_16-50__cm3-boot-unix64le.7z

or this

2. cm3-d5.11.9-ZZYYXX-20230928_16-50__cm3-boot-AMD64_LINUX-d5.11.9-20230926_14-06.tar.xz

or this

3. cm3-boot-AMD64_LINUX-None.tar.xz

from
https://github.com/VictorMiasnikov/cm3/releases/tag/d5.11.9-ZZYYXX-20230928_16-50

P.S. "Linux" and "le" has been used in naming as tradition. All files are universal

[VictorMiasnikov]

( . . .) d5.11.9-ZZYYXX-20230928_16-50

Sorry: Release 16-50 is specific ...

First try cm3-d5.11.9-ZZYYXX-20230928_16-50__cm3-boot-unix64le.7z

As alternate variant You can try files from

from
d5.11.9-ZZYYXX-20230721_16-29

[VictorMiasnikov]

P.S.

( . . .) I am interested to build it on PowerPC (Big-endian, of course). Can it be bootstrapped from C/C++, without pre-built binary (which may not exist)?

Are You have PPC or PPC64?

I've found:

https://raw.githubusercontent.com/macports/macports-ports/master/lang/cm3/Portfile

plus

https://modula3.elegosoft.com/cm3/cm3-min-POSIX-PPC_DARWIN-5.4.0.tgz

[barracuda156]

@VictorMiasnikov Oh wow, thank you very much! The port seems to outdated and broken across the board, but I will probably be able to fix it.
https://ports.macports.org/port/cm3/details

P. S. Somehow I missed its existence, maybe searched for a different name. Anyway, all good now, thanks everyone for helping with this.

[VictorMiasnikov]

@VictorMiasnikov Oh wow, thank you very much! The port seems to outdated and broken across the board, but I will probably be able to fix it. https://ports.macports.org/port/cm3/details

You are welcome!

I've found and cm3 5.8.6 on

https://modula3.elegosoft.com/cm3/releng/download.html

P.S.
Last 25 minutes I wanted found this:
https://modula3.elegosoft.com/cm3/uploaded-archives/

and found it.

There is not most modern DARWIN_PPC, but there is SPARC64_SOLARIS
It may be useful for prepare bootstrap

I.e. I hope that it be useful... I only going to try install QEMU for non-ARM32 / non-ARM64 / non-AMD64 CPU architectures

[jaykrell]

Unfortunately they aren't quite universal.
It was a goal, but I didn't quite get there.
They word-size and endian specific.
So arm32==x86==ppc32le
arm64==amd64==riscv64
sparc64==ppc64be
sparc32==ppc32be

So for "Unix" you'd need 4 bootstraps: LittleEndian32bit, LittleEndian64bit, BigEndian32bit, BigEndian64bit.
And then Windows is another factor, though Windows BigEndian is barely a thing (Xbox360, some Windows CE platforms).

You can just about ignore all this stuff..64bit little endian is prevalent, but here we are discussing 32bit big endian Mac PowerPC.

The endian specificity is due to code breaking down floats into bitfields.
And maybe some bitfields in garbage collector, I don't remember if I fixed those.

[jaykrell]

It is pretty easy to build all these...we just don't quite have the automation setup, sorry.
Any of them can be cross built from any other.
Also I never finished porting the build scripts from Python2 to Python3...Python3 compatibility, what a mess. :(

[barracuda156]

@VictorMiasnikov Thank you, this is very helpful.

Do you know if I need exactly the same version for bootstrap binary and the main source? The latest Darwin PPC binary seems to be 5.8.6.