- (cond
- ((or (valid-funtype '((constant-arg (integer 1 29))
- (constant-arg (integer 0 29))
- fixnum)
- 'fixnum)
- (valid-funtype '((constant-arg (integer 1 29))
- (constant-arg (integer 0 29))
- (signed-byte 32))
- 'fixnum)
- (valid-funtype '((constant-arg (integer 1 29))
- (constant-arg (integer 0 29))
- (unsigned-byte 32))
- 'fixnum))
- (values :transform
- '(lambda (size posn integer)
- (%%ldb integer size posn))))
- (t (values :default nil))))
+ (flet ((validp (type width)
+ (and (valid-funtype `((constant-arg (integer 1 29))
+ (constant-arg (mod ,width))
+ ,type)
+ 'fixnum)
+ (destructuring-bind (size posn integer)
+ (sb!c::basic-combination-args node)
+ (declare (ignore integer))
+ (<= (+ (sb!c::lvar-value size)
+ (sb!c::lvar-value posn))
+ width)))))
+ (if (or (validp 'fixnum 29)
+ (validp '(signed-byte 32) 32)
+ (validp '(unsigned-byte 32) 32))
+ (values :transform '(lambda (size posn integer)
+ (%%ldb integer size posn)))
+ (values :default nil))))