fix(v4.0.0): shorter chains of calls in the compiler capsule

Measured, compiling a DO loop left one return entry spare under
INTERPRET and a defining word called from inside another word
overflowed the nine-entry return stack (D-2); the prompt loop will take
one more.

C@ and C! shift without a loop.  The code generator shifts each opcode
into the word being built, so nothing is placed by a counted shift, and
the address masks come from a table.  The dictionary search, the
in-liner, the end of a loop and the making of a data word are each one
word reached by a jump.

Every kind of line now leaves at least three return entries spare while
it compiles; a word run from the interpreter has six; and CREATE ...
DOES> works from the prompt, from a word, and from a word that calls
that.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
This commit is contained in:
rajames
2026-10-04 11:17:58 -04:00
co-authored by Claude Opus 5.5
parent dac7ffac92
commit 806f876ee0
9 changed files with 165 additions and 123 deletions
+15 -8
View File
@@ -44,23 +44,30 @@ header DNEGATE
L1: drop 1 + ;
\ ---- section 5.3: bytes --------------------------------------------------
\ The shifts are written out, eight to a line, where DECOMPOSITION.md 5.3 has
\ a FOR ... UNEXT loop: a loop keeps its count on the return stack, and C@ and
\ C! are at the bottom of every chain of calls in the compiler capsule, where
\ there is not an entry to spare (D-2). The result is the same.
macro 8/ 2/ 2/ 2/ 2/ 2/ 2/ 2/ 2/ endmacro
macro 8* 2* 2* 2* 2* 2* 2* 2* 2* endmacro
header C@
: C@ ( baddr -- c )
dup 2/ 2/ a! 3 and
if K0 -1 + if K1 -1 + if K2
drop @ 23 FOR 2/ UNEXT 255 and ;
K2: drop @ 15 FOR 2/ UNEXT 255 and ;
K1: drop @ 7 FOR 2/ UNEXT 255 and ;
drop @ 8/ 8/ 8/ 255 and ;
K2: drop @ 8/ 8/ 255 and ;
K1: drop @ 8/ 255 and ;
K0: drop @ 255 and ;
header C!
: C! ( c baddr -- )
dup 2/ 2/ a! 3 and push 255 and pop
dup 2/ 2/ a! 3 and
if K0 -1 + if K1 -1 + if K2
drop 23 FOR 2* UNEXT @ 4278190080 inv and + ! ;
K2: drop 15 FOR 2* UNEXT @ -16711681 and + ! ;
K1: drop 7 FOR 2* UNEXT @ -65281 and + ! ;
K0: drop @ -256 and + ! ;
drop 8* 8* 8* 4278190080 and @ 4278190080 inv and + ! ;
K2: drop 8* 8* 16711680 and @ -16711681 and + ! ;
K1: drop 8* 65280 and @ -65281 and + ! ;
K0: drop 255 and @ -256 and + ! ;
\ ---- section 5.9: strings ------------------------------------------------
header CMOVE