X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=OPTIMIZATIONS;h=0ca48de3354fcab34182d424658a16d8ad663898;hb=3a4229d4a91f04da79dfc7366433682f8c979f0a;hp=28068847ba715b735ebc6659da740fd0c7140322;hpb=043a8820506178134574627c2d7f07dc79070bd8;p=sbcl.git

diff --git a/OPTIMIZATIONS b/OPTIMIZATIONS
index 2806884..0ca48de 100644
--- a/OPTIMIZATIONS
+++ b/OPTIMIZATIONS
@@ -90,25 +90,14 @@ VOP DATA-VECTOR-SET/SIMPLE-STRING V2!14[EDI] t32[EAX] t30[S2]>t33[CL]
                 (incf x)))))))
    (format t "~A~%" x)))
 --------------------------------------------------------------------------------
-#7
-(defun foo (x)
-  (declare (optimize speed (debug 0)))
-  (if (< x 0) x (foo (1- x))))
-
-SBCL generates a full call of FOO (but CMUCL does not).
-
-Partial explanation: CMUCL does generate a full (tail) call to FOO if
-*BLOCK-COMPILE* is NIL.  Maybe this is because in that case CMUCL doesn't 
-generate a temporary(?) function in its IR1-TRANSLATOR for %DEFUN?
---------------------------------------------------------------------------------
 #8
 (defun foo (d)
   (declare (optimize (speed 3) (safety 0) (debug 0)))
   (declare (type (double-float 0d0 1d0) d))
   (loop for i fixnum from 1 to 5
-     for x1 double-float = (sin d) ;;; !!!
-     do (loop for j fixnum from 1 to 4
-             sum x1 double-float)))
+        for x1 double-float = (sin d) ;;; !!!
+        do (loop for j fixnum from 1 to 4
+                 sum x1 double-float)))
 
 Without the marked declaration Python will use boxed representation for X1.
 
@@ -162,3 +151,37 @@ tests lowtag.
 FAST-+/FIXNUM and similar should accept unboxed arguments in interests
 of representation selection. Problem: inter-TN dependencies.
 --------------------------------------------------------------------------------
+#14
+The derived type of (/ (THE (DOUBLE-FLOAT (0D0)) X) (THE (DOUBLE-FLOAT
+1D0) Y)) is (DOUBLE-FLOAT 0.0d0). While it might be reasonable, it is
+better to derive (OR (MEMBER 0.0d0) (DOUBLE-FLOAT (0.0d0))).
+--------------------------------------------------------------------------------
+#15
+On the alpha, the system is reluctant to refer directly to a constant bignum,
+preferring to load a large constant through a slow sequence of instructions,
+then cons up a bignum for it:
+
+(LAMBDA (A)
+  (DECLARE (OPTIMIZE (SAFETY 1) (SPEED 3) (DEBUG 1))
+           (TYPE (INTEGER -10000 10000) A)
+           (IGNORABLE A))
+  (CASE A
+    ((89 125 16) (ASH A (MIN 18 -706)))
+    (T (DPB -3 (BYTE 30 30) -1))))
+--------------------------------------------------------------------------------
+#16
+(do ((i 0 (1+ i)))
+    ((= i (the (integer 0 100) n)))
+  ...)
+
+It is commonly expected for Python to derive (FIXNUMP I). (If ``='' is
+replaced with ``>='', Python will do.)
+--------------------------------------------------------------------------------
+#17 
+Type tests for (ARRAY BIT), (ARRAY T) and similar go through full
+%TYPEP, even though it is relatively simple to establish the arrayness
+of an object and also to obtain the element type of an array.  As of
+sbcl-0.8.12.30, this affects at least DUMP-OBJECT through
+COMPOUND-OBJECT-P, and (LABELS MAYBE-EMIT-MAKE-LOAD-FORMS GROVEL)
+through TYPEP UNBOXED-ARRAY, within the compiler itself.
+--------------------------------------------------------------------------------