Commit Graph

15 Commits

Author SHA1 Message Date
Virgil Dupras
a7dcb522c2 Make br cells 1 byte wide
The 1 byte limitation has been effective for a while now, but I
hadn't made the move yet, I wanted to see if the limitation would
cause me problems. It doesn't.

Doing this now slightly facilitates the IY->BC move in z80.

Bootstrapping: if you try to recreate the CVM binary from the
previous commit with this code, you'll have bootstrapping problems.
The first bootstrap will compile a binary with 2-bytes wide cells
but branching conditionals that yields 1-byte cells. That's bad.

I got around the issue by temporarily inserting a "397 399 LOADR"
instruction in cvm/xcomp.fs, right before the xcomp overrides. This
way, I force 1-byte cells everywhere on the first compiliation,
which then allows me to apply the logic change in cvm/vm.c and have
a properly running binary.
2020-07-06 07:27:50 -04:00
Virgil Dupras
f2f520cacc Extract (br), (?br) and (loop)'s code out of stable ABI zone
There is now no more actual code in stable ABI, only references.
This makes refactoring of this code much easier. For example,
changing IY to BC as the IP register.
2020-07-05 14:57:18 -04:00
Virgil Dupras
4a91ee5c9c Extract (s) code from stable ABI zone
Only its jump addr remains.
2020-07-05 08:54:22 -04:00
Virgil Dupras
94cb76520a Refer to stable wordref by direct offset in "hot zone" immediates
Previously, it was impossible to cross-compile Collapse OS from a
binary-offsetted Collapse OS because stable ABI wordrefs would have
a wrongly offsetted address.

This solves the problem by replacing those wordrefs by direct,
hardcoded stable ABI offset references.
2020-07-05 07:09:11 -04:00
Virgil Dupras
2d9a07d215 blkunpack: don't include trailing empty lines
This was becoming heavy to manage.
2020-06-23 06:52:34 -04:00
Virgil Dupras
2be2f74a43 Make literal word routines into regular native words 2020-06-17 14:25:32 -04:00
Virgil Dupras
ea9833d4ff Remove LITA
It was useful when we still had the relinker, but now it has no use.
I was waiting a bit to see if the distinction would be useful again,
but it seems like it won't.
2020-06-17 13:50:42 -04:00
Virgil Dupras
f6ded7712e VE: add 't'
This is the first commit I do entirely in VE. It's a habit I'm planning
on taking as it helps a lot to find usability issues.
2020-06-11 18:12:01 -04:00
Virgil Dupras
2d17b4e8ec Make string length-prefixed instead of null-terminated
I'm not sure why I chose null-terminated initially. Probably because
the z80asm version had null-terminated strings.

Length-prefixes strings are the traditional form of strings in Forth
and it's a bit easier to work with them with traditional forth words
when they're under this form.
2020-05-25 20:34:52 -04:00
Virgil Dupras
2d2a846b25 Inline SCPY
I'm planning a string reform and it's standing in the way.
2020-05-24 14:19:25 -04:00
Virgil Dupras
ed2b91411a Limit ourselves to 8-bit branching
I'm planning on going back to 8-bit branching. 16-bit br cells incur
a non-negligible penalty and, while at first 64 words (128 bytes
forward or backward) seemed a bit limiting, I now don't see why one
would ever construct such a big branch. It would be un-forthy.

Also, I looked at using BC instead of IY to hold IP and the transition
would be a lot easier with 8-bit branching.

In this commit, all I do is add overflow checks in IF. The mechanic
below doesn't change. I'll give myself some time to think it over so
that I avoid yet another back and forth.
2020-05-24 10:16:25 -04:00
Virgil Dupras
bd38d80f9c Move Cross-compiled core from B390 to B350
and renamed it "Core words". Also, reworded the presentation.
2020-05-15 22:44:49 -04:00
Virgil Dupras
c681cb639d Add words >< and =><= 2020-05-04 22:30:29 -04:00
Virgil Dupras
3d908cef3a Move all parsing words to Inner core
This allows us to get rid of the (parse*) indirection.
2020-05-02 21:21:47 -04:00
Virgil Dupras
44403c3d4c Move icore to blkfs
The way is clear for complete stage1 bootstrapping on the RC2014
target!
2020-04-23 15:14:14 -04:00