X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=OPTIMIZATIONS;h=7c51f473ac7e0301e123fa41db6094598db835d1;hb=4ed3f0d08c3a57a6762018d9622f253ab9d0f2b6;hp=51fcb32f0e2a426469ae07f97796e3b2d1685a19;hpb=51c5280a4b41f8c51d434643cde3e18af4113473;p=sbcl.git

diff --git a/OPTIMIZATIONS b/OPTIMIZATIONS
index 51fcb32..7c51f47 100644
--- a/OPTIMIZATIONS
+++ b/OPTIMIZATIONS
@@ -154,5 +154,18 @@ 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 (DOUBLE-FLOAT (-0.0d0)).
+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))))
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