Mercurial > hg > index.cgi
diff src/vars.s @ 80:bb50ac9fdf37
Checkpoint with very basic integer and floating point arithmetic, untested
This commit has implementations for floating point add, subtract, multiply,
and divide, along with 32 bit signed integer equivalents. These can probably
be optimized and they are untested.
| author | William Astle <lost@l-w.ca> |
|---|---|
| date | Sat, 07 Oct 2023 02:56:59 -0600 |
| parents | 2d52cd154ed1 |
| children | 663d8e77b579 |
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--- a/src/vars.s Sun Sep 10 23:18:17 2023 -0600 +++ b/src/vars.s Sat Oct 07 02:56:59 2023 -0600 @@ -39,8 +39,29 @@ tok_kwnum rmb 1 ; the actual token number tok_kwmatchl rmb 1 ; the length of the best match during lookup tok_kwmatch rmb 2 ; the current best matched token number -val0 rmb val.size ; value accumulator 0 -val1 rmb val.size ; value accumulator 1 +; General value accumulators used during expression evaluation +val0 rmb val.size ; value accumulator 0 - current expression value +val1 rmb val.size ; value accumulator 1 - usually left operand of binary operator +; The fpa0 and fpa1 areas are used for scratch work during floating point operations. They are only used +; by floating point operations. This saves a fair fiew clock cycles over simply working off the index register +; pointers passed into the routines and it also allows for being able to leave the input operands for the +; routines unmodified, or to overlap the input and output operands. These floating point accumulators can hold +; the maximum precision floating point values used by the system. +fpa0 rmb fpa.size ; floating point accumulator 1 +fpa1 rmb fpa.size ; floating point accumulator 1 +fpa0extra rmb 1 ; "extra" bytes for calculations +fpa0extra1 rmb 1 +fpa0extra2 rmb 1 +fpa0extra3 rmb 1 +fpa0extra4 rmb 1 +fpa0extra5 rmb 1 +fpa0extra6 rmb 1 +fpa0extra7 rmb 1 +fpa0extra8 rmb 1 +fpa0extra9 rmb 1 +fpa0extra10 rmb 1 +fpa0extra11 rmb 1 +fpa0extra12 rmb 1 rmb 0x71-* ; align RSTFLG/RSTVEC for stock ROM compatibility RSTFLG rmb 1 ; 0x55 if RSTVEC is valid RSTVEC rmb 2 ; points to warm start routine (must start with NOP)