--------------------------------------------------------------------------------
#21
(defun-with-dx foo ()
- (let ((dx (list (list 1 2) (list 3 4)
+ (let ((dx (list (list 1 2) (list 3 4))))
(declare (dynamic-extent dx))
- ...)))))
+ ...))
External list in DX is allocated on stack, but internal are not.
--------------------------------------------------------------------------------
rewritten with &MORE vectors.
b. Implement local unknown-values mv-call (useful for fast type checking).
--------------------------------------------------------------------------------
-#25
-EQL is implemented generically in situations where this isn't necessary.
-
-(defun f (x y)
- (declare (type (or symbol fixnum) x)
- (optimize speed (safety 0) (debug 0)))
- (eql x y))
-
-SUBTYPEP is smart enough to determine that this type is a subtype
-of (and (or (not number) fixnum) (not character))
-
-This sitation where the type is (OR NULL FIXNUM) comes up
-in cl-bench, for example in the value returned by POSITION.
+#26
+SBCL cannot derive upper bound for I and uses generic arithmetic here:
+
+(defun foo (l)
+ (declare (vector l))
+ (dotimes (i (length l))
+ (if (block nil
+ (map-foo (lambda (x) (if x (return t)))
+ l))
+ t
+ nil)))
+
+(So the constraint propagator or a possible future SSA-convertor
+should know the connection between an NLE and its CLEANUP.)
+--------------------------------------------------------------------------------
+#27
+Initialization of stack-allocated arrays is inefficient: we always
+fill the vector with zeroes, even when it is not needed (as for
+platforms with conservative GC or for arrays of unboxed objectes) and
+is performed later explicitely.
+--------------------------------------------------------------------------------
+#28
+a. Accessing raw slots in structure instances is more inefficient than
+it could be; if we placed raw slots before the header word, we would
+not need to do arithmetic at runtime to access them. (But beware:
+this would complicate handling of the interior pointer).
+
+b. (Also note that raw slots are currently disabled on HPPA)
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