| 2010-01-18 06:30:20 |
Stas Boukarev |
description |
Reported by Stas Boukarev on sbcl-devel.
(loop for i from most-negative-fixnum to most-positive-fixnum
count i))
expands into
(BLOCK NIL
(LET ((I MOST-NEGATIVE-FIXNUM))
(DECLARE (TYPE (AND REAL NUMBER) I))
(LET ((#:LOOP-SUM-899 0))
(DECLARE (TYPE FIXNUM #:LOOP-SUM-899))
(SB-LOOP::LOOP-BODY NIL
(NIL NIL
(WHEN (> I '536870911) (GO SB-LOOP::END-LOOP)) NIL)
((WHEN I (SETQ #:LOOP-SUM-899 (1+ #:LOOP-SUM-899))))
(NIL (SB-LOOP::LOOP-REALLY-DESETQ I (1+ I))
(WHEN (> I '536870911) (GO SB-LOOP::END-LOOP)) NIL)
((RETURN-FROM NIL #:LOOP-SUM-899))))))
Where counter has type FIXNUM even though the count becomes a bignum.
Note also the (AND REAL NUMBER) declaration for I: smarter placement of the termination test would allow a FIXNUM declaration there. |
Reported by Stas Boukarev on sbcl-devel.
(loop for i from most-negative-fixnum to most-positive-fixnum
count i))
expands into
(BLOCK NIL
(LET ((I MOST-NEGATIVE-FIXNUM))
(DECLARE (TYPE (AND REAL NUMBER) I))
(LET ((#:LOOP-SUM-899 0))
(DECLARE (TYPE FIXNUM #:LOOP-SUM-899))
(SB-LOOP::LOOP-BODY NIL
(NIL NIL
(WHEN (> I '536870911) (GO SB-LOOP::END-LOOP)) NIL)
((WHEN I (SETQ #:LOOP-SUM-899 (1+ #:LOOP-SUM-899))))
(NIL (SB-LOOP::LOOP-REALLY-DESETQ I (1+ I))
(WHEN (> I '536870911) (GO SB-LOOP::END-LOOP)) NIL)
((RETURN-FROM NIL #:LOOP-SUM-899))))))
Where counter has type FIXNUM even though the count becomes a bignum.
Note also the (AND REAL NUMBER) declaration for I: smarter placement of the termination test would allow a FIXNUM declaration there.
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