X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=OPTIMIZATIONS;h=7c51f473ac7e0301e123fa41db6094598db835d1;hb=4ed3f0d08c3a57a6762018d9622f253ab9d0f2b6;hp=3b6ebe1af9ee460cc7237c6d6e2bab75cd73799f;hpb=d6cacf136631916da0db8bbe32554ca499e17589;p=sbcl.git

diff --git a/OPTIMIZATIONS b/OPTIMIZATIONS
index 3b6ebe1..7c51f47 100644
--- a/OPTIMIZATIONS
+++ b/OPTIMIZATIONS
@@ -151,3 +151,21 @@ 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))))
+--------------------------------------------------------------------------------