X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Flate-type.lisp;h=d1eaa9e40be7acb7ea798c3d04e8b0215bdb0ad0;hb=65aa68a4f6a671db80596f136dec549322b28ddd;hp=16b605d7dc8b4e174ad849a0daa20fb938475bd5;hpb=49319a8c7f3527b0d452b8f07bdabe02283e8ff7;p=sbcl.git

diff --git a/src/code/late-type.lisp b/src/code/late-type.lisp
index 16b605d..d1eaa9e 100644
--- a/src/code/late-type.lisp
+++ b/src/code/late-type.lisp
@@ -432,8 +432,9 @@
       1
       (values-type-max-value-count type)))
 
+;;; VALUES type with a single value.
 (defun type-single-value-p (type)
-  (and (values-type-p type)
+  (and (%values-type-p type)
        (not (values-type-rest type))
        (null (values-type-optional type))
        (singleton-p (values-type-required type))))
@@ -1731,7 +1732,7 @@
              (eql low high)
              (eql (numeric-type-complexp type) :real)
              (member (numeric-type-class type) '(integer rational
-                                                 #!-sb-xc-host float)))
+                                                 #-sb-xc-host float)))
         (values t (numeric-type-low type))
         (values nil nil))))
 
@@ -1883,10 +1884,12 @@
 
 ;;; Return a numeric type that is a supertype for both TYPE1 and TYPE2.
 ;;;
-;;; Old comment, probably no longer applicable:
-;;;
-;;;   ### Note: we give up early to keep from dropping lots of
-;;;   information on the floor by returning overly general types.
+;;; Binding *APPROXIMATE-NUMERIC-UNIONS* to T allows merging non-adjacent
+;;; numeric types, eg (OR (INTEGER 0 12) (INTEGER 20 128)) => (INTEGER 0 128),
+;;; the compiler does this occasionally during type-derivation to avoid
+;;; creating absurdly complex unions of numeric types.
+(defvar *approximate-numeric-unions* nil)
+
 (!define-type-method (number :simple-union2) (type1 type2)
   (declare (type numeric-type type1 type2))
   (cond ((csubtypep type1 type2) type2)
@@ -1902,7 +1905,8 @@
              ((and (eq class1 class2)
                    (eq format1 format2)
                    (eq complexp1 complexp2)
-                   (or (numeric-types-intersect type1 type2)
+                   (or *approximate-numeric-unions*
+                       (numeric-types-intersect type1 type2)
                        (numeric-types-adjacent type1 type2)
                        (numeric-types-adjacent type2 type1)))
               (make-numeric-type
@@ -1924,7 +1928,8 @@
                    (integerp (numeric-type-low type2))
                    (integerp (numeric-type-high type2))
                    (= (numeric-type-low type2) (numeric-type-high type2))
-                   (or (numeric-types-adjacent type1 type2)
+                   (or *approximate-numeric-unions*
+                       (numeric-types-adjacent type1 type2)
                        (numeric-types-adjacent type2 type1)))
               (make-numeric-type
                :class 'rational
@@ -1943,7 +1948,8 @@
                    (integerp (numeric-type-low type1))
                    (integerp (numeric-type-high type1))
                    (= (numeric-type-low type1) (numeric-type-high type1))
-                   (or (numeric-types-adjacent type1 type2)
+                   (or *approximate-numeric-unions*
+                       (numeric-types-adjacent type1 type2)
                        (numeric-types-adjacent type2 type1)))
               (make-numeric-type
                :class 'rational
@@ -2398,14 +2404,8 @@ used for a COMPLEX component.~:@>"
          (values nil t))
         ((or (unknown-type-p (array-type-element-type type1))
              (unknown-type-p (array-type-element-type type2)))
-         (multiple-value-bind (equalp certainp)
-             (type= (array-type-element-type type1)
-                    (array-type-element-type type2))
-           ;; By its nature, the call to TYPE= should never return
-           ;; NIL, T, as we don't know what the UNKNOWN-TYPE will grow
-           ;; up to be.  -- CSR, 2002-08-19
-           (aver (not (and (not equalp) certainp)))
-           (values equalp certainp)))
+         (type= (array-type-element-type type1)
+                (array-type-element-type type2)))
         (t
          (values (type= (array-type-specialized-element-type type1)
                         (array-type-specialized-element-type type2))
@@ -2904,11 +2904,12 @@ used for a COMPLEX component.~:@>"
                           :high (if (null (numeric-type-high type1))
                                     nil
                                     (list (1+ (numeric-type-high type1)))))))
-         (type-union type1
-                     (apply #'type-intersection
-                            (remove (specifier-type '(not integer))
-                                    (intersection-type-types type2)
-                                    :test #'type=))))
+         (let* ((intersected (intersection-type-types type2))
+                (remaining   (remove (specifier-type '(not integer))
+                                     intersected
+                                     :test #'type=)))
+           (and (not (equal intersected remaining))
+                (type-union type1 (apply #'type-intersection remaining)))))
         (t
          (let ((accumulator *universal-type*))
            (do ((t2s (intersection-type-types type2) (cdr t2s)))