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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.
13 lines
327 B
Plaintext
13 lines
327 B
Plaintext
: IF ( -- a | a: br cell addr )
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0x3f ( ?br ) , H@ 1 ALLOT ( br cell allot )
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; IMMEDIATE
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: THEN ( a -- | a: br cell addr )
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DUP H@ -^ _bchk SWAP ( a-H a ) C!
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; IMMEDIATE
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: ELSE ( a1 -- a2 | a1: IF cell a2: ELSE cell )
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0x3b ( br ) ,
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1 ALLOT
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[COMPILE] THEN
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H@ 1- ( push a. 1- for allot offset )
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; IMMEDIATE
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