X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=contrib%2Fsb-rotate-byte%2Fcompiler.lisp;h=2d0f1954c4ae0e96705effe484218264b10150c7;hb=a28e5039d2a5087ca3c04376fd423ec0cedb64ad;hp=2e7d5e1d7f1bc179613d2cab5aab069bc57458c5;hpb=939275c1bc2f18ef93cd1dd4ab35a18f6008cfd9;p=sbcl.git

diff --git a/contrib/sb-rotate-byte/compiler.lisp b/contrib/sb-rotate-byte/compiler.lisp
index 2e7d5e1..2d0f195 100644
--- a/contrib/sb-rotate-byte/compiler.lisp
+++ b/contrib/sb-rotate-byte/compiler.lisp
@@ -56,3 +56,15 @@
   ;; FIXME: What happens when, as here, the two type specifiers for
   ;; COUNT overlap?  Which gets to run first?
   '(%unsigned-32-rotate-byte count integer))
+
+;; Generic implementation for platforms that don't supply VOPs for 32-bit
+;; rotate.
+#-(or x86 ppc)
+(deftransform %unsigned-32-rotate-byte ((.count. .integer.)
+                                        ((integer -31 31)
+                                         (unsigned-byte 32)) *)
+  '(if (< .count. 0)
+       (logior (ldb (byte 32 0) (ash .integer. (+ .count. 32)))
+               (ash .integer. .count.))
+       (logior (ldb (byte 32 0) (ash .integer. .count.))
+               (ash .integer. (- .count. 32)))))