feat(v4.0.0): # keeps its high quotient on the data stack

`#` held the high quotient on the return stack across its second
UM/MOD, which was the deepest point of pictured output once C! was made
call-free. It now rotates it under the division on the data stack
(-ROT in line: SWAP push SWAP pop).

Headroom, return entries: <# #S #> 2 -> 3, the signed picture 1 -> 2.
Data room is unchanged.

Same 4716 checks per width at 32- and 64-bit cells, optimised and
ASan+UBSan (`make test`, `make sanitize`); the headroom checks now
require the new figures.

Test results on the amd64 host only. This is a development check, not
acceptance (JUSTIFICATION.md section 16).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
This commit is contained in:
rajames
2026-10-03 11:51:03 -04:00
co-authored by Claude Opus 5.5
parent 638aeb6636
commit 7a21f07ad5
2 changed files with 14 additions and 9 deletions
+5 -3
View File
@@ -452,7 +452,7 @@ All output reaches the console through `EMIT` (DEV).
| Word | Fate | Notes |
| --- | --- | --- |
| `<#` `#` `#S` `HOLD` `SIGN` `#>` | CAP | Pictured output over `UM/MOD` and a 64-byte hold buffer, filled backwards from its end `HEND` through the pointer `HLD`. Standard stack effects (v3 took its double low cell on top, and its tolerant `#>` popped `ud` only if present; neither is kept). Otherwise v3's behaviour: digits `0`–`9` then `A`–`Z`; `BASE` outside 2–36 reads as 10; 63 characters; `HOLD` of a value outside 0–255 or into a full buffer stores nothing and sets `NODE-ERROR` (D-13). Definitions below. Executed on the golden model (2026-10-03) against a C reference in bases 2, 3, 8, 10, 16, 36 and four invalid ones. `<# #S #>` leaves its caller 3 data cells and 2 return entries; the signed picture `dup push ABS 0 <# #S pop SIGN #>` leaves 1 return entry. The deepest point is inside `#`, which holds the high quotient on the return stack across its second `UM/MOD`. `#`, `#S`, `HOLD` and `SIGN` clobber `A` and `B`. |
| `<#` `#` `#S` `HOLD` `SIGN` `#>` | CAP | Pictured output over `UM/MOD` and a 64-byte hold buffer, filled backwards from its end `HEND` through the pointer `HLD`. Standard stack effects (v3 took its double low cell on top, and its tolerant `#>` popped `ud` only if present; neither is kept). Otherwise v3's behaviour: digits `0`–`9` then `A`–`Z`; `BASE` outside 2–36 reads as 10; 63 characters; `HOLD` of a value outside 0–255 or into a full buffer stores nothing and sets `NODE-ERROR` (D-13). Definitions below. Executed on the golden model (2026-10-03) against a C reference in bases 2, 3, 8, 10, 16, 36 and four invalid ones. `<# #S #>` leaves its caller 4 data cells and 3 return entries; the signed picture `dup push ABS 0 <# #S pop SIGN #>` leaves 2 return entries. `#`, `#S`, `HOLD` and `SIGN` clobber `A` and `B`. |
| `HLD` | CAP | Variable: byte address of the first held character. |
| `.` `.R` `U.` `U.R` `D.` `D.R` | CAP | Built on pictured output and `TYPE`. |
| `.S` | RET | No visible stack pointer (D-2). |
@@ -472,7 +472,8 @@ All output reaches the console through `EMIT` (DEV).
ROOM: drop HLD b! @b -1 + dup !b jump C!
: SIGN ( n -- ) -if L1 drop 45 jump HOLD L1: drop ;
: # ( ud1 -- ud2 )
0 (BASE) UM/MOD push (BASE) UM/MOD pop ROT \ qlo qhi rem
0 (BASE) UM/MOD -ROT \ qhi lo rem1
(BASE) UM/MOD -ROT \ qlo qhi rem
dup -10 + -if L1 drop 48 + jump L2 L1: drop 55 + L2: jump HOLD
: #S ( ud -- 0 0 ) L: # over over OR if L1 drop jump L L1: drop ;
: #> ( ud -- baddr u ) drop drop HLD b! @b HEND over push inv pop + inv ;
@@ -481,7 +482,8 @@ All output reaches the console through `EMIT` (DEV).
`#` divides the double by the base in two `UM/MOD` steps, the high cell first and its remainder
leading the low cell; the last remainder is the digit. `HOLD`, `SIGN` and `#` end with a jump to the
next word rather than a call, so `C!` returns straight to their caller and two return-stack entries
are saved. `ROT` is in line.
are saved. `#` keeps the high quotient under the second division on the data stack, not on the
return stack. `-ROT` is in line (`SWAP push SWAP pop`).
### 5.9 Strings, parsing, and input