Commit Graph

14 Commits

Author SHA1 Message Date
Virgil Dupras
3aa681ceca Remove ";" word
The ":" now takes care of scanning for ";". Conceptually, having
";" as an immediate word is slightly simpler than the approach in
this commit, but when bootstrapping is involved, this simpler
approach gets murkier.

Moreover, it got even murkier-er when trying to de-stabilize EXIT,
so here we are.
2020-09-19 20:22:23 -04:00
Virgil Dupras
eefbf66e95 De-stabilize (br), (?br), (loop), (s)
When writing the xcomp documentation, I realized that with careful
threading and by accepting a bit of code duplication in the xcomp
toolset, I could de-stabilize a couple of words.

(n) and EXIT are a bit trickier, but I think it can be done. It
would be nice to get rid of stable wordrefs...
2020-09-19 13:54:01 -04:00
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
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
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
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
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
389b23fe1a Change C<? mechanic
It's now a simple flag updated by the C< implementation. No more
routine pointer.

The goal is to avoid tons of "ok" during a LOAD operation.
2020-04-25 09:10:25 -04:00
Virgil Dupras
816563e2e3 Stop LOADing on ABORT
This is done by adding a "C<* override" layer that is reset to 0 on
ABORT.

The problem was that when ABORT happened during a LOAD, we had a
resetted RSP and started from a clean INTERPRET, but LOAD didn't
have the opportunity to restore C<*, which caused it to continue
interpreting from the faulty BLK.

With a C<* override, we don't need to *restore* C<*, we just need to
clear the override.
2020-04-24 14:10:40 -04:00
Virgil Dupras
af39b37dd1 Replace the "> " prompt with the more traditional "ok" one
This is more than cosmetic, it's also highly usable. The presence
or absence of the "ok" message allows us to know whether the command
aborted. Previously, the "> " prompt appeared when the system expected
a prompt in the INTERPRET context, whether the previous command aborted
or not.

Also, this allows us to get rid of that ugly FLAGS global variable.
2020-04-24 12:10:07 -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