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ocaml: phase 4 bitwise ops land/lor/lxor/lsl/lsr/asr + bits.ml baseline (+5 tests, 607 total)
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The binop precedence table already had land/lor/lxor/lsl/lsr/asr
(iter 0 setup) but eval-op fell through to 'unknown operator' for
all of them. SX doesn't expose host bitwise primitives, so each is
implemented in eval.sx via arithmetic on the host:

  land/lor/lxor:  mask & shift loop, accumulating 1<<k digits
  lsl k:          repeated * 2 k times
  lsr k:          repeated floor (/ 2) k times
  asr:            aliased to lsr (no sign extension at our bit width)

bits.ml baseline: popcount via 'while m > 0 do if m land 1 = 1 then
... ; m := m lsr 1 done'. Sum of popcount(1023, 5, 1024, 0xff) = 10
+ 2 + 1 + 8 = 21.

  5 land 3 = 1
  5 lor 3 = 7
  5 lxor 3 = 6
  1 lsl 8 = 256
  256 lsr 4 = 16

41 baseline programs total.
This commit is contained in:
giles
2026-05-09 09:15:00 +00:00
parent 70b9b4f6cf
commit aaaf054441
5 changed files with 113 additions and 0 deletions
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73
lib/ocaml/eval.sx
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@@ -513,6 +513,79 @@
((= op ">=") (>= lhs rhs))
((= op "&&") (and lhs rhs))
((= op "||") (or lhs rhs))
;; Bitwise ops — implemented via arithmetic since SX doesn't
;; expose host bitwise primitives.
((= op "land")
(let ((r 0) (f 1) (a lhs) (b rhs))
(begin
(define loop
(fn ()
(when (and (> a 0) (> b 0))
(begin
(when (and (= (mod a 2) 1) (= (mod b 2) 1))
(set! r (+ r f)))
(set! a (floor (/ a 2)))
(set! b (floor (/ b 2)))
(set! f (* f 2))
(loop)))))
(loop)
r)))
((= op "lor")
(let ((r 0) (f 1) (a lhs) (b rhs))
(begin
(define loop
(fn ()
(when (or (> a 0) (> b 0))
(begin
(when (or (= (mod a 2) 1) (= (mod b 2) 1))
(set! r (+ r f)))
(set! a (floor (/ a 2)))
(set! b (floor (/ b 2)))
(set! f (* f 2))
(loop)))))
(loop)
r)))
((= op "lxor")
(let ((r 0) (f 1) (a lhs) (b rhs))
(begin
(define loop
(fn ()
(when (or (> a 0) (> b 0))
(begin
(when (not (= (mod a 2) (mod b 2)))
(set! r (+ r f)))
(set! a (floor (/ a 2)))
(set! b (floor (/ b 2)))
(set! f (* f 2))
(loop)))))
(loop)
r)))
((= op "lsl")
(let ((r lhs) (k rhs))
(begin
(define loop
(fn ()
(when (> k 0) (begin (set! r (* r 2)) (set! k (- k 1)) (loop)))))
(loop)
r)))
((= op "lsr")
(let ((r lhs) (k rhs))
(begin
(define loop
(fn ()
(when (> k 0)
(begin (set! r (floor (/ r 2))) (set! k (- k 1)) (loop)))))
(loop)
r)))
((= op "asr")
(let ((r lhs) (k rhs))
(begin
(define loop
(fn ()
(when (> k 0)
(begin (set! r (floor (/ r 2))) (set! k (- k 1)) (loop)))))
(loop)
r)))
((= op "or") (or lhs rhs))
((= op "|>") (rhs lhs))
(else (error (str "ocaml-eval: unknown operator " op))))))