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a7dcb522c2
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.
16 lines
601 B
Plaintext
16 lines
601 B
Plaintext
( Now we have "as late as possible" stuff. See B70 and B260. )
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: _bchk DUP 0x7f + 0xff > IF LIT< br-ovfl (print) ABORT THEN ;
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: DO 0x33 ( 2>R ) , H@ ; IMMEDIATE
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: LOOP 0x43 ( loop ) , H@ - _bchk C, ; IMMEDIATE
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( LEAVE is implemented in low xcomp )
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: LITN 0x23 ( n ) , , ;
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( gets its name at the very end. can't comment afterwards )
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: _ BEGIN LIT< ) WORD S= UNTIL ; IMMEDIATE
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: _ ( : will get its name almost at the very end )
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(entry) 1 ( compiled ) C,
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BEGIN
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WORD FIND
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IF ( is word ) DUP IMMED? IF EXECUTE ELSE , THEN
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ELSE ( maybe number ) (parse) LITN THEN
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AGAIN ;
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