~vdupras/duskos: bootlo: rewrite "for" in HAL

64208509a28101653791de438b1870b4a809a443 — Virgil Dupras 13 days ago 00206d2

bootlo: rewrite "for" in HAL

Being used very often, the general speedup should be appreciable, especially
since we piggy-back on [+n], setting the Z flag. I didn't rewrite "for2"
because the logic is more complex in Low HAL without all branching conditions.
Not worth it.

patch browse .tar.gz

1 files changed, 5 insertions(+), 3 deletions(-)

M fs/xcomp/bootlo.fs

M fs/xcomp/bootlo.fs => fs/xcomp/bootlo.fs +5 -3

@@ 225,11 225,13 @@ alias execute | immediate
 : unyield BRSZ RSP) [+n], ; immediate
 : break 16 rs+, [compile] ahead to _breaklbl ; immediate
 
-:iterator for ( n -- )
-  ?dup if to i begin yield to1- i i not until then unyield ;
+:iterator for ( n -- ) [
+  1 W+n, RSP) 4 +) !, drop, ahead
+  begin yield swap then -1 RSP) 4 +) [+n], NZ) branchC, drop
+  unyield exit,
 
 :iterator for2 ( lo hi -- )
-  2dup < if to j to i begin yield to1+ i i j >= until else 2drop then unyield ;
+  to j to i i j < if begin yield to1+ i i j >= until then unyield ;
 
 code fill ( a u c -- )
   W>A, PSP) 4 +) @, W<>A, 1 PSP) [+n], begin \ A=a W=c P+0=u+1