mirror of
https://github.com/hsoft/collapseos.git
synced 2024-09-07 12:18:45 +10:00
It's a bit more inconvenient in terms of register protection (BC is much more generally useful than IY), but it makes tight spots such as next and execute much faster, so I think it's worth it.
16 lines
542 B
Plaintext
16 lines
542 B
Plaintext
lblnext BSET PC ORG @ 0x1b + ! ( next )
|
|
( This routine is jumped to at the end of every word. In it,
|
|
we jump to current IP, but we also take care of increasing
|
|
it by 2 before jumping. )
|
|
( Before we continue: are stacks within bounds? )
|
|
( PS ) HL PS_ADDR LDdn,
|
|
SP SUBHLd,
|
|
JRC, lblofl BWR ( abortUnderflow-B285 )
|
|
( RS ) IX PUSH, HL POP,
|
|
DE RS_ADDR LDdn,
|
|
DE SUBHLd,
|
|
JRC, lblofl BWR ( IX < RS_ADDR? abortUnderflow-B285 )
|
|
LDA(BC), E A LDrr, BC INCd,
|
|
LDA(BC), D A LDrr, BC INCd,
|
|
( continue to execute )
|