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
338 B
Plaintext
16 lines
338 B
Plaintext
CODE (br)
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L1 BSET ( used in ?br and loop )
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PC ORG @ 0x3d + ! ( stable ABI JP )
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E 0 IY+ LDrIXY, D 0 LDri,
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7 E BIT, IFNZ, D DECr, THEN,
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DE ADDIYd,
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;CODE
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CODE (?br)
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PC ORG @ 0x41 + ! ( stable ABI JP )
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HL POP,
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HLZ,
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JRZ, L1 BWR ( br + 1. False, branch )
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( True, skip next byte and don't branch )
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IY INCd,
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;CODE
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