collapseos/blk/397

( Now we have "as late as possible" stuff. See B70 and B270. )
: _bchk DUP 0x7f + 0xff > IF LIT< br-ovfl (print) ABORT THEN ;
: DO 0x33 ( 2>R ) , H@ ; IMMEDIATE
: LOOP 0x80 ( loop ) , H@ - _bchk , ; IMMEDIATE
( LEAVE is implemented in low xcomp )
: LITN 0xbf ( n ) , , ;
( gets its name at the very end. can't comment afterwards )
: _ BEGIN LIT< ) WORD S= UNTIL ; IMMEDIATE
: _ ( : will get its name almost at the very end )
    (entry) 1 ( compiled ) C,
    BEGIN
        WORD FIND
        IF ( is word ) DUP IMMED? IF EXECUTE ELSE , THEN
        ELSE ( maybe number ) (parse) LITN THEN
    AGAIN ;
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 21:09:11 +10:00			`( Now we have "as late as possible" stuff. See B70 and B270. )`
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. 2020-05-25 00:01:46 +10:00			`: _bchk DUP 0x7f + 0xff > IF LIT< br-ovfl (print) ABORT THEN ;`
z80/8086: extract 2>R code from stable ABI zone Only its jump at 0x33 remains. I've also fixed a strange offset oddity in 8086's (n) placement. It was off by 2, but strangely, it ran properly. Anyway, now it's fixed. 2020-07-05 22:03:15 +10:00			`: DO 0x33 ( 2>R ) , H@ ; IMMEDIATE`
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 21:09:11 +10:00			`: LOOP 0x80 ( loop ) , H@ - _bchk , ; IMMEDIATE`
Move Cross-compiled core from B390 to B350 and renamed it "Core words". Also, reworded the presentation. 2020-05-16 12:44:49 +10:00			`( LEAVE is implemented in low xcomp )`
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 21:09:11 +10:00			`: LITN 0xbf ( n ) , , ;`
Move Cross-compiled core from B390 to B350 and renamed it "Core words". Also, reworded the presentation. 2020-05-16 12:44:49 +10:00			`( gets its name at the very end. can't comment afterwards )`
			`: _ BEGIN LIT< ) WORD S= UNTIL ; IMMEDIATE`
			`: _ ( : will get its name almost at the very end )`
Make word routines into word types Instead of having wordref point to core word routines, I made them into word 4 word types. It liberates space into the stable ABI and should make porting to other arches easier. I'm also thinking of combining word type with the namelen field for precious bytes saving, but not now... 2020-06-18 11:41:01 +10:00			`(entry) 1 ( compiled ) C,`
Move Cross-compiled core from B390 to B350 and renamed it "Core words". Also, reworded the presentation. 2020-05-16 12:44:49 +10:00			`BEGIN`
			`WORD FIND`
			`IF ( is word ) DUP IMMED? IF EXECUTE ELSE , THEN`
			`ELSE ( maybe number ) (parse) LITN THEN`
			`AGAIN ;`