collapseos/blk/446

( TODO: move these words with other native words. )
H@ 4 + XCURRENT ! ( make next CODE have 0 prev field )
CODE (br) L1 BSET ( used in ?br )
    DI DX MOVxx, AL [DI] MOVr[], AH AH XORrr, CBW,
    DX AX ADDxx,
;CODE
CODE (?br)
    AX POPx, AX AX ORxx, JZ, L1 @ RPCs, ( False, branch )
    ( True, skip next byte and don't branch )
    DX INCx,
;CODE
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. 2020-07-06 04:57:18 +10:00			`( TODO: move these words with other native words. )`
Extract EXIT code from stable ABI zone 2020-07-06 03:41:12 +10:00			`H@ 4 + XCURRENT ! ( make next CODE have 0 prev field )`
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. 2020-07-06 04:57:18 +10:00			`CODE (br) L1 BSET ( used in ?br )`
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 21:27:50 +10:00			`DI DX MOVxx, AL [DI] MOVr[], AH AH XORrr, CBW,`
			`DX AX ADDxx,`
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. 2020-07-06 04:57:18 +10:00			`;CODE`
			`CODE (?br)`
			`AX POPx, AX AX ORxx, JZ, L1 @ RPCs, ( False, branch )`
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 21:27:50 +10:00			`( True, skip next byte and don't branch )`
			`DX INCx,`
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. 2020-07-06 04:57:18 +10:00			`;CODE`