X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fppc%2Farith.lisp;h=c633a1332170292d282e3f0c09c0f56856e64417;hb=d319b944d934f3efbb01a2a345c46bafd40857d0;hp=56910ac5b8a67ccaa1ee260dd4081b61522644d6;hpb=0db7f91050aeb2dc2f98946eefa251ffd6b96402;p=sbcl.git

diff --git a/src/compiler/ppc/arith.lisp b/src/compiler/ppc/arith.lisp
index 56910ac..c633a13 100644
--- a/src/compiler/ppc/arith.lisp
+++ b/src/compiler/ppc/arith.lisp
@@ -18,7 +18,6 @@
   (:effects)
   (:affected))
 
-
 (define-vop (fixnum-unop fast-safe-arith-op)
   (:args (x :scs (any-reg)))
   (:results (res :scs (any-reg)))
@@ -52,8 +51,6 @@
   (:translate lognot)
   (:generator 1
     (inst not res x)))
-
-
 
 ;;;; Binary fixnum operations.
 
@@ -61,7 +58,7 @@
 
 (define-vop (fast-fixnum-binop fast-safe-arith-op)
   (:args (x :target r :scs (any-reg zero))
-	 (y :target r :scs (any-reg zero)))
+         (y :target r :scs (any-reg zero)))
   (:arg-types tagged-num tagged-num)
   (:results (r :scs (any-reg)))
   (:result-types tagged-num)
@@ -69,7 +66,7 @@
 
 (define-vop (fast-unsigned-binop fast-safe-arith-op)
   (:args (x :target r :scs (unsigned-reg zero))
-	 (y :target r :scs (unsigned-reg zero)))
+         (y :target r :scs (unsigned-reg zero)))
   (:arg-types unsigned-num unsigned-num)
   (:results (r :scs (unsigned-reg)))
   (:result-types unsigned-num)
@@ -77,18 +74,26 @@
 
 (define-vop (fast-signed-binop fast-safe-arith-op)
   (:args (x :target r :scs (signed-reg zero))
-	 (y :target r :scs (signed-reg zero)))
+         (y :target r :scs (signed-reg zero)))
   (:arg-types signed-num signed-num)
   (:results (r :scs (signed-reg)))
   (:result-types signed-num)
   (:note "inline (signed-byte 32) arithmetic"))
 
-
 (define-vop (fast-fixnum-binop-c fast-safe-arith-op)
   (:args (x :target r :scs (any-reg zero)))
   (:info y)
   (:arg-types tagged-num
-	      (:constant (and (signed-byte 14) (not (integer 0 0)))))
+              (:constant (and (signed-byte 14) (not (integer 0 0)))))
+  (:results (r :scs (any-reg)))
+  (:result-types tagged-num)
+  (:note "inline fixnum arithmetic"))
+
+(define-vop (fast-fixnum-binop30-c fast-safe-arith-op)
+  (:args (x :target r :scs (any-reg zero)))
+  (:info y)
+  (:arg-types tagged-num
+              (:constant (and (signed-byte 30) (not (integer 0 0)))))
   (:results (r :scs (any-reg)))
   (:result-types tagged-num)
   (:note "inline fixnum arithmetic"))
@@ -97,7 +102,16 @@
   (:args (x :target r :scs (any-reg zero)))
   (:info y)
   (:arg-types tagged-num
-	      (:constant (and (unsigned-byte 14) (not (integer 0 0)))))
+              (:constant (and (unsigned-byte 14) (not (integer 0 0)))))
+  (:results (r :scs (any-reg)))
+  (:result-types tagged-num)
+  (:note "inline fixnum logical op"))
+
+(define-vop (fast-fixnum-logop30-c fast-safe-arith-op)
+  (:args (x :target r :scs (any-reg zero)))
+  (:info y)
+  (:arg-types tagged-num
+              (:constant (and (unsigned-byte 16) (not (integer 0 0)))))
   (:results (r :scs (any-reg)))
   (:result-types tagged-num)
   (:note "inline fixnum logical op"))
@@ -106,25 +120,61 @@
   (:args (x :target r :scs (unsigned-reg zero)))
   (:info y)
   (:arg-types unsigned-num
-	      (:constant (and (signed-byte 16) (not (integer 0 0)))))
+              (:constant (and (signed-byte 16) (not (integer 0 0)))))
   (:results (r :scs (unsigned-reg)))
   (:result-types unsigned-num)
   (:note "inline (unsigned-byte 32) arithmetic"))
 
+(define-vop (fast-unsigned-binop32-c fast-safe-arith-op)
+  (:args (x :target r :scs (unsigned-reg zero)))
+  (:info y)
+  (:arg-types unsigned-num
+              (:constant (and (unsigned-byte 32) (not (integer 0 0)))))
+  (:results (r :scs (unsigned-reg)))
+  (:result-types unsigned-num)
+  (:note "inline (unsigned-byte 32) arithmetic"))
+
+(define-vop (fast-signed-binop32-c fast-safe-arith-op)
+  (:args (x :target r :scs (signed-reg zero)))
+  (:info y)
+  (:arg-types signed-num
+              (:constant (and (signed-byte 32) (not (integer 0 0)))))
+  (:results (r :scs (signed-reg)))
+  (:result-types signed-num)
+  (:note "inline (signed-byte 32) arithmetic"))
+
 (define-vop (fast-unsigned-logop-c fast-safe-arith-op)
   (:args (x :target r :scs (unsigned-reg zero)))
   (:info y)
   (:arg-types unsigned-num
-	      (:constant (and (unsigned-byte 16) (not (integer 0 0)))))
+              (:constant (and (unsigned-byte 16) (not (integer 0 0)))))
   (:results (r :scs (unsigned-reg)))
   (:result-types unsigned-num)
   (:note "inline (unsigned-byte 32) logical op"))
 
+(define-vop (fast-unsigned-logop32-c fast-safe-arith-op)
+  (:args (x :target r :scs (unsigned-reg zero)))
+  (:info y)
+  (:arg-types unsigned-num
+              (:constant (and (unsigned-byte 32) (not (integer 0 0)))))
+  (:results (r :scs (unsigned-reg)))
+  (:result-types unsigned-num)
+  (:note "inline (unsigned-byte 32) logical op"))
+
+(define-vop (fast-signed-logop32-c fast-safe-arith-op)
+  (:args (x :target r :scs (signed-reg zero)))
+  (:info y)
+  (:arg-types signed-num
+              (:constant (and (unsigned-byte 32) (not (integer 0 0)))))
+  (:results (r :scs (signed-reg)))
+  (:result-types signed-num)
+  (:note "inline (signed-byte 32) logical op"))
+
 (define-vop (fast-signed-binop-c fast-safe-arith-op)
   (:args (x :target r :scs (signed-reg zero)))
   (:info y)
   (:arg-types signed-num
-	      (:constant (and (signed-byte 16) (not (integer 0 0)))))
+              (:constant (and (signed-byte 16) (not (integer 0 0)))))
   (:results (r :scs (signed-reg)))
   (:result-types signed-num)
   (:note "inline (signed-byte 32) arithmetic"))
@@ -133,87 +183,245 @@
   (:args (x :target r :scs (signed-reg zero)))
   (:info y)
   (:arg-types signed-num
-	      (:constant (and (unsigned-byte 16) (not (integer 0 0)))))
+              (:constant (and (unsigned-byte 16) (not (integer 0 0)))))
   (:results (r :scs (signed-reg)))
   (:result-types signed-num)
-  (:note "inline (signed-byte 32) arithmetic"))
-
+  (:note "inline (signed-byte 32) logical op"))
 
 (eval-when (:compile-toplevel :load-toplevel :execute)
 
-(defmacro define-var-binop (translate untagged-penalty op)
+(defmacro !define-var-binop (translate untagged-penalty op
+                             &optional arg-swap restore-fixnum-mask)
   `(progn
      (define-vop (,(symbolicate "FAST-" translate "/FIXNUM=>FIXNUM")
-		  fast-fixnum-binop)
+                  fast-fixnum-binop)
+       ,@(when restore-fixnum-mask
+           `((:temporary (:sc non-descriptor-reg) temp)))
        (:translate ,translate)
        (:generator 2
-	 (inst ,op r x y))) 
+         ,(if arg-swap
+             `(inst ,op ,(if restore-fixnum-mask 'temp 'r) y x)
+             `(inst ,op ,(if restore-fixnum-mask 'temp 'r) x y))
+         ;; FIXME: remind me what convention we used for 64bitizing
+         ;; stuff?  -- CSR, 2003-08-27
+         ,@(when restore-fixnum-mask
+             `((inst clrrwi r temp (1- n-lowtag-bits))))))
      (define-vop (,(symbolicate "FAST-" translate "/SIGNED=>SIGNED")
-		  fast-signed-binop)
+                  fast-signed-binop)
        (:translate ,translate)
        (:generator ,(1+ untagged-penalty)
-	 (inst ,op r x y))) 
+         ,(if arg-swap
+             `(inst ,op r y x)
+             `(inst ,op r x y))))
      (define-vop (,(symbolicate "FAST-" translate "/UNSIGNED=>UNSIGNED")
-		  fast-unsigned-binop)
+                  fast-unsigned-binop)
        (:translate ,translate)
        (:generator ,(1+ untagged-penalty)
-	 (inst ,op r x y)))))
-
-
-(defmacro define-const-binop (translate untagged-penalty op)
+         ,(if arg-swap
+             `(inst ,op r y x)
+             `(inst ,op r x y))))))
+
+;;; FIXME: the code has really only been checked for adds; we could do
+;;; subtracts, too, but my brain is not up to the task of figuring out
+;;; signs and borrows.
+(defmacro !define-const-binop (translate untagged-penalty op &optional (shifted-op nil))
   `(progn
-     
      (define-vop (,(symbolicate 'fast- translate '-c/fixnum=>fixnum)
-		  fast-fixnum-binop-c)
+                  ,(if shifted-op
+                       'fast-fixnum-binop30-c
+                       'fast-fixnum-binop-c))
        (:translate ,translate)
+       ,@(when shifted-op
+          `((:temporary (:sc any-reg :target r) temp)))
        (:generator 1
-	 (inst ,op r x (fixnumize y))))
+        ,(if shifted-op
+             `(let* ((y (fixnumize y))
+                     (high-half (ldb (byte 16 16) y))
+                     (low-half (ldb (byte 16 0) y)))
+               ;; Compare %LR in insts.lisp.
+               (cond
+                 ((and (logbitp 15 low-half) (= high-half #xffff))
+                  ;; Let sign-extension do the work for us, but make sure
+                  ;; to turn LOW-HALF into a signed integer.
+                  (inst ,op r x (dpb low-half (byte 16 0) -1)))
+                 ((and (not (logbitp 15 low-half)) (zerop high-half))
+                  (inst ,op r x low-half))
+                 ((zerop low-half)
+                  (inst ,shifted-op r x (if (logbitp 15 high-half)
+                                            (dpb high-half (byte 16 0) -1)
+                                            high-half)))
+                 (t
+                  ;; Check to see whether compensating for the sign bit
+                  ;; of LOW-HALF is necessary.
+                  (let ((high-half (let ((top (if (logbitp 15 low-half)
+                                                  (ldb (byte 16 0)
+                                                       (1+ high-half))
+                                                  high-half)))
+                                     (if (logbitp 15 top)
+                                         (dpb top (byte 16 0) -1)
+                                         top))))
+                    (inst ,shifted-op temp x high-half)
+                    (inst ,op r temp low-half)))))
+             `(inst ,op r x (fixnumize y)))))
      (define-vop (,(symbolicate 'fast- translate '-c/signed=>signed)
-		  fast-signed-binop-c)
+                  ,(if shifted-op
+                       'fast-signed-binop32-c
+                       'fast-signed-binop-c))
        (:translate ,translate)
+       ,@(when shifted-op
+          `((:temporary (:sc non-descriptor-reg :target r) temp)))
        (:generator ,untagged-penalty
-	 (inst ,op r x y)))
+        ,(if shifted-op
+             `(let ((high-half (ldb (byte 16 16) y))
+                    (low-half (ldb (byte 16 0) y)))
+               ;; Compare %LR in insts.lisp.
+               (cond
+                 ((and (logbitp 15 low-half) (= high-half #xffff))
+                  ;; Let sign-extension do the work for us, but make sure
+                  ;; to turn LOW-HALF into a signed integer.
+                  (inst ,op r x (dpb low-half (byte 16 0) -1)))
+                 ((and (not (logbitp 15 low-half)) (zerop high-half))
+                  (inst ,op r x low-half))
+                 ((zerop low-half)
+                  (inst ,shifted-op r x (if (logbitp 15 high-half)
+                                            (dpb high-half (byte 16 0) -1)
+                                            high-half)))
+                 (t
+                  ;; Check to see whether compensating for the sign bit
+                  ;; of LOW-HALF is necessary.
+                  (let ((high-half (let ((top (if (logbitp 15 low-half)
+                                                  (ldb (byte 16 0)
+                                                       (1+ high-half))
+                                                  high-half)))
+                                     (if (logbitp 15 top)
+                                         (dpb top (byte 16 0) -1)
+                                         top))))
+                    (inst ,shifted-op temp x high-half)
+                    (inst ,op r temp low-half)))))
+             `(inst ,op r x y))))
      (define-vop (,(symbolicate 'fast- translate '-c/unsigned=>unsigned)
-		  fast-unsigned-binop-c)
+                  ,(if shifted-op
+                       'fast-unsigned-binop32-c
+                       'fast-unsigned-binop-c))
        (:translate ,translate)
+       ,@(when shifted-op
+          `((:temporary (:sc non-descriptor-reg :target r) temp)))
        (:generator ,untagged-penalty
-	 (inst ,op r x y)))))
-
-(defmacro define-const-logop (translate untagged-penalty op)
+        ,(if shifted-op
+             `(let ((high-half (ldb (byte 16 16) y))
+                    (low-half (ldb (byte 16 0) y)))
+               ;; Compare %LR in insts.lisp.
+               (cond
+                 ((and (logbitp 15 low-half) (= high-half #xffff))
+                  ;; Let sign-extension do the work for us, but make sure
+                  ;; to turn LOW-HALF into a signed integer.
+                  (inst ,op r x (dpb low-half (byte 16 0) -1)))
+                 ((and (not (logbitp 15 low-half)) (zerop high-half))
+                  (inst ,op r x low-half))
+                 ((zerop low-half)
+                  (inst ,shifted-op r x (if (logbitp 15 high-half)
+                                            (dpb high-half (byte 16 0) -1)
+                                            high-half)))
+                 (t
+                  ;; Check to see whether compensating for the sign bit
+                  ;; of LOW-HALF is necessary.
+                  (let ((high-half (let ((top (if (logbitp 15 low-half)
+                                                  (ldb (byte 16 0)
+                                                       (1+ high-half))
+                                                  high-half)))
+                                     (if (logbitp 15 top)
+                                         (dpb top (byte 16 0) -1)
+                                         top))))
+                    (inst ,shifted-op temp x high-half)
+                    (inst ,op r temp low-half)))))
+             `(inst ,op r x y))))))
+
+;;; For logical operations, we don't have to worry about signed bit
+;;; propagation from the lower half of a 32-bit operand.
+(defmacro !define-const-logop (translate untagged-penalty op &optional (shifted-op nil))
   `(progn
-     
      (define-vop (,(symbolicate 'fast- translate '-c/fixnum=>fixnum)
-		  fast-fixnum-logop-c)
+                  ,(if shifted-op
+                       'fast-fixnum-logop30-c
+                       'fast-fixnum-logop-c))
        (:translate ,translate)
+       ,@(when shifted-op
+          `((:temporary (:sc any-reg :target r) temp)))
        (:generator 1
-	 (inst ,op r x (fixnumize y))))
+        ,(if shifted-op
+             `(let* ((y (fixnumize y))
+                     (high-half (ldb (byte 16 16) y))
+                     (low-half (ldb (byte 16 0) y)))
+               (cond
+                 ((zerop high-half) (inst ,op r x low-half))
+                 ((zerop low-half) (inst ,shifted-op r x high-half))
+                 (t
+                  (inst ,shifted-op temp x high-half)
+                  (inst ,op r temp low-half))))
+             `(inst ,op r x (fixnumize y)))))
      (define-vop (,(symbolicate 'fast- translate '-c/signed=>signed)
-		  fast-signed-logop-c)
+                  ,(if shifted-op
+                       'fast-signed-logop32-c
+                       'fast-signed-logop-c))
        (:translate ,translate)
+       ,@(when shifted-op
+          `((:temporary (:sc non-descriptor-reg :target r) temp)))
        (:generator ,untagged-penalty
-	 (inst ,op r x y)))
+        ,(if shifted-op
+             `(let ((high-half (ldb (byte 16 16) y))
+                    (low-half (ldb (byte 16 0) y)))
+               (cond
+                 ((zerop high-half) (inst ,op r x low-half))
+                 ((zerop low-half) (inst ,shifted-op r x high-half))
+                 (t
+                  (inst ,shifted-op temp x high-half)
+                  (inst ,op r temp low-half))))
+             `(inst ,op r x y))))
      (define-vop (,(symbolicate 'fast- translate '-c/unsigned=>unsigned)
-		  fast-unsigned-logop-c)
+                  ,(if shifted-op
+                       'fast-unsigned-logop32-c
+                       'fast-unsigned-logop-c))
        (:translate ,translate)
+       ,@(when shifted-op
+          `((:temporary (:sc non-descriptor-reg :target r) temp)))
        (:generator ,untagged-penalty
-	 (inst ,op r x y)))))
+        ,(if shifted-op
+             `(let ((high-half (ldb (byte 16 16) y))
+                    (low-half (ldb (byte 16 0) y)))
+               (cond
+                 ((zerop high-half) (inst ,op r x low-half))
+                 ((zerop low-half) (inst ,shifted-op r x high-half))
+                 (t
+                  (inst ,shifted-op temp x high-half)
+                  (inst ,op r temp low-half))))
+             `(inst ,op r x y))))))
 
 ); eval-when
 
-(define-var-binop + 4 add)
-(define-var-binop - 4 sub)
-(define-var-binop logand 2 and)
-(define-var-binop logandc2 2 andc)
-(define-var-binop logior 2 or)
-(define-var-binop logorc2 2 orc)
-(define-var-binop logxor 2 xor)
-(define-var-binop logeqv 2 eqv)
-
-(define-const-binop + 4 addi)
-(define-const-binop - 4 subi)
-(define-const-logop logand 2 andi.)
-(define-const-logop logior 2 ori)
-(define-const-logop logxor 2 xori)
+(!define-var-binop + 4 add)
+(!define-var-binop - 4 sub)
+(!define-var-binop logand 2 and)
+(!define-var-binop logandc1 2 andc t)
+(!define-var-binop logandc2 2 andc)
+(!define-var-binop logior 2 or)
+(!define-var-binop logorc1 2 orc t t)
+(!define-var-binop logorc2 2 orc nil t)
+(!define-var-binop logxor 2 xor)
+(!define-var-binop logeqv 2 eqv nil t)
+(!define-var-binop lognand 2 nand nil t)
+(!define-var-binop lognor 2 nor nil t)
+
+(!define-const-binop + 4 addi addis)
+(!define-const-binop - 4 subi)
+;;; Implementing a 32-bit immediate version of LOGAND wouldn't be any
+;;; better than loading the 32-bit constant via LR and then performing
+;;; an /AND/.  So don't bother.  (It would be better in some cases, such
+;;; as when one half of the word is zeros--we save a register--but we
+;;; would have specified one temporary register in the VOP, so we lose
+;;; any possible advantage.)
+(!define-const-logop logand 2 andi.)
+(!define-const-logop logior 2 ori oris)
+(!define-const-logop logxor 2 xori xoris)
 
 
 ;;; Special case fixnum + and - that trap on overflow.  Useful when we
@@ -226,14 +434,13 @@
   (:note "safe inline fixnum arithmetic")
   (:generator 4
     (let* ((no-overflow (gen-label)))
-      (inst mcrxr :cr0)
+      (inst mtxer zero-tn)
       (inst addo. r x y)
       (inst bns no-overflow)
       (inst unimp (logior (ash (reg-tn-encoding r) 5)
-			  fixnum-additive-overflow-trap))
+                          fixnum-additive-overflow-trap))
       (emit-label no-overflow))))
 
-
 (define-vop (-/fixnum fast--/fixnum=>fixnum)
   (:policy :safe)
   (:results (r :scs (any-reg descriptor-reg)))
@@ -241,58 +448,131 @@
   (:note "safe inline fixnum arithmetic")
   (:generator 4
     (let* ((no-overflow (gen-label)))
-      (inst mcrxr :cr0)
+      (inst mtxer zero-tn)
       (inst subo. r x y)
       (inst bns no-overflow)
       (inst unimp (logior (ash (reg-tn-encoding r) 5)
-			  fixnum-additive-overflow-trap))
+                          fixnum-additive-overflow-trap))
       (emit-label no-overflow))))
 
+(define-vop (fast-*/fixnum=>fixnum fast-fixnum-binop)
+  (:temporary (:scs (non-descriptor-reg)) temp)
+  (:translate *)
+  (:generator 2
+    (inst srawi temp y 2)
+    (inst mullw r x temp)))
+
+(define-vop (fast-*-c/fixnum=>fixnum fast-fixnum-binop-c)
+  (:translate *)
+  (:arg-types tagged-num
+              (:constant (and (signed-byte 16) (not (integer 0 0)))))
+  (:generator 1
+    (inst mulli r x y)))
+
+(define-vop (fast-*-bigc/fixnum=>fixnum fast-fixnum-binop-c)
+  (:translate *)
+  (:arg-types tagged-num
+              (:constant (and fixnum (not (signed-byte 16)))))
+  (:temporary (:scs (non-descriptor-reg)) temp)
+  (:generator 1
+    (inst lr temp y)
+    (inst mullw r x temp)))
+
+(define-vop (fast-*/signed=>signed fast-signed-binop)
+  (:translate *)
+  (:generator 4
+    (inst mullw r x y)))
 
+(define-vop (fast-*-c/signed=>signed fast-signed-binop-c)
+  (:translate *)
+  (:generator 3
+    (inst mulli r x y)))
+
+(define-vop (fast-*/unsigned=>unsigned fast-unsigned-binop)
+  (:translate *)
+  (:generator 4
+    (inst mullw r x y)))
+
+(define-vop (fast-*-c/unsigned=>unsigned fast-unsigned-binop-c)
+  (:translate *)
+  (:generator 3
+    (inst mulli r x y)))
+
 ;;; Shifting
 
+(macrolet ((def (name sc-type type result-type cost)
+             `(define-vop (,name)
+                (:note "inline ASH")
+                (:translate ash)
+                (:args (number :scs (,sc-type))
+                       (amount :scs (signed-reg unsigned-reg immediate)))
+                (:arg-types ,type positive-fixnum)
+                (:results (result :scs (,result-type)))
+                (:result-types ,type)
+                (:policy :fast-safe)
+                (:generator ,cost
+                   (sc-case amount
+                     ((signed-reg unsigned-reg)
+                      (inst slw result number amount))
+                     (immediate
+                      (let ((amount (tn-value amount)))
+                        (aver (> amount 0))
+                        (inst slwi result number amount))))))))
+  ;; FIXME: There's the opportunity for a sneaky optimization here, I
+  ;; think: a FAST-ASH-LEFT-C/FIXNUM=>SIGNED vop.  -- CSR, 2003-09-03
+  (def fast-ash-left/fixnum=>fixnum any-reg tagged-num any-reg 2)
+  (def fast-ash-left/signed=>signed signed-reg signed-num signed-reg 3)
+  (def fast-ash-left/unsigned=>unsigned unsigned-reg unsigned-num unsigned-reg 3))
+
 (define-vop (fast-ash/unsigned=>unsigned)
   (:note "inline ASH")
   (:args (number :scs (unsigned-reg) :to :save)
-	 (amount :scs (signed-reg immediate)))
+         (amount :scs (signed-reg)))
   (:arg-types (:or unsigned-num) signed-num)
   (:results (result :scs (unsigned-reg)))
   (:result-types unsigned-num)
   (:translate ash)
   (:policy :fast-safe)
   (:temporary (:sc non-descriptor-reg) ndesc)
-  (:generator 3
-    (sc-case amount
-      (signed-reg
-       (let ((positive (gen-label))
-	     (done (gen-label)))
-	 (inst cmpwi amount 0)
-	 (inst neg ndesc amount)
-	 (inst bge positive)
-	 (inst cmpwi ndesc 31)
-	 (inst srw result number ndesc)
-	 (inst ble done)
-	 (inst srwi result number 31)
-	 (inst b done)
-
-	 (emit-label positive)
-	 ;; The result-type assures us that this shift will not overflow.
-	 (inst slw result number amount)
-
-	 (emit-label done)))
+  (:generator 5
+    (let ((positive (gen-label))
+          (done (gen-label)))
+      (inst cmpwi amount 0)
+      (inst neg ndesc amount)
+      (inst bge positive)
+      (inst cmpwi ndesc 31)
+      (inst srw result number ndesc)
+      (inst ble done)
+      (move result zero-tn)
+      (inst b done)
+
+      (emit-label positive)
+      ;; The result-type assures us that this shift will not overflow.
+      (inst slw result number amount)
 
-      (immediate
-       (let ((amount (tn-value amount)))
-	 (if (minusp amount)
-	     (let ((amount (min 31 (- amount))))
-	       (inst srwi result number amount))
-	     (inst slwi result number amount)))))))
+      (emit-label done))))
 
+(define-vop (fast-ash-c/unsigned=>unsigned)
+  (:note "inline constant ASH")
+  (:args (number :scs (unsigned-reg)))
+  (:info amount)
+  (:arg-types unsigned-num (:constant integer))
+  (:results (result :scs (unsigned-reg)))
+  (:result-types unsigned-num)
+  (:translate ash)
+  (:policy :fast-safe)
+  (:generator 4
+    (cond
+      ((and (minusp amount) (< amount -31)) (move result zero-tn))
+      ((minusp amount) (inst srwi result number (- amount)))
+      ;; possible because this is used in the modular version too
+      ((> amount 31) (move result zero-tn))
+      (t (inst slwi result number amount)))))
 
 (define-vop (fast-ash/signed=>signed)
   (:note "inline ASH")
   (:args (number :scs (signed-reg) :to :save)
-	 (amount :scs (signed-reg immediate)))
+         (amount :scs (signed-reg immediate)))
   (:arg-types (:or signed-num) signed-num)
   (:results (result :scs (signed-reg)))
   (:result-types (:or signed-num))
@@ -303,28 +583,28 @@
     (sc-case amount
       (signed-reg
        (let ((positive (gen-label))
-	     (done (gen-label)))
-	 (inst cmpwi amount 0)
-	 (inst neg ndesc amount)
-	 (inst bge positive)
-	 (inst cmpwi ndesc 31)
-	 (inst sraw result number ndesc)
-	 (inst ble done)
-	 (inst srawi result number 31)
-	 (inst b done)
-
-	 (emit-label positive)
-	 ;; The result-type assures us that this shift will not overflow.
-	 (inst slw result number amount)
-
-	 (emit-label done)))
+             (done (gen-label)))
+         (inst cmpwi amount 0)
+         (inst neg ndesc amount)
+         (inst bge positive)
+         (inst cmpwi ndesc 31)
+         (inst sraw result number ndesc)
+         (inst ble done)
+         (inst srawi result number 31)
+         (inst b done)
+
+         (emit-label positive)
+         ;; The result-type assures us that this shift will not overflow.
+         (inst slw result number amount)
+
+         (emit-label done)))
 
       (immediate
        (let ((amount (tn-value amount)))
-	 (if (minusp amount)
-	     (let ((amount (min 31 (- amount))))
-	       (inst srawi result number amount))
-	     (inst slwi result number amount)))))))
+         (if (minusp amount)
+             (let ((amount (min 31 (- amount))))
+               (inst srawi result number amount))
+             (inst slwi result number amount)))))))
 
 
 
@@ -334,19 +614,29 @@
   (:policy :fast-safe)
   (:args (arg :scs (signed-reg)))
   (:arg-types signed-num)
-  (:results (res :scs (any-reg)))
-  (:result-types positive-fixnum)
-  (:temporary (:scs (non-descriptor-reg) :to (:argument 0)) shift)
+  (:results (res :scs (unsigned-reg)))
+  (:result-types unsigned-num)
   (:generator 6
     ; (integer-length arg) = (- 32 (cntlz (if (>= arg 0) arg (lognot arg))))
     (let ((nonneg (gen-label)))
-      (inst cntlzw. shift arg)
+      (inst cntlzw. res arg)
       (inst bne nonneg)
-      (inst not shift arg)
-      (inst cntlzw shift shift)
+      (inst not res arg)
+      (inst cntlzw res res)
       (emit-label nonneg)
-      (inst slwi shift shift 2)
-      (inst subfic res  shift (fixnumize 32)))))
+      (inst subfic res res 32))))
+
+(define-vop (unsigned-byte-32-len)
+  (:translate integer-length)
+  (:note "inline (unsigned-byte 32) integer-length")
+  (:policy :fast-safe)
+  (:args (arg :scs (unsigned-reg)))
+  (:arg-types unsigned-num)
+  (:results (res :scs (unsigned-reg)))
+  (:result-types unsigned-num)
+  (:generator 4
+    (inst cntlzw res arg)
+    (inst subfic res res 32)))
 
 (define-vop (unsigned-byte-32-count)
   (:translate logcount)
@@ -359,7 +649,7 @@
   (:temporary (:scs (non-descriptor-reg) :from (:argument 0)) shift temp)
   (:generator 30
     (let ((loop (gen-label))
-	  (done (gen-label)))
+          (done (gen-label)))
       (inst add. shift zero-tn arg)
       (move res zero-tn)
       (inst beq done)
@@ -373,6 +663,56 @@
       (emit-label done))))
 
 
+;;;; Modular functions:
+(define-modular-fun lognot-mod32 (x) lognot :unsigned 32)
+(define-vop (lognot-mod32/unsigned=>unsigned)
+  (:translate lognot-mod32)
+  (:args (x :scs (unsigned-reg)))
+  (:arg-types unsigned-num)
+  (:results (res :scs (unsigned-reg)))
+  (:result-types unsigned-num)
+  (:policy :fast-safe)
+  (:generator 1
+    (inst not res x)))
+
+(define-vop (fast-ash-left-mod32-c/unsigned=>unsigned
+             fast-ash-c/unsigned=>unsigned)
+  (:translate ash-left-mod32))
+
+(define-vop (fast-ash-left-mod32/unsigned=>unsigned
+             fast-ash-left/unsigned=>unsigned))
+(deftransform ash-left-mod32 ((integer count)
+                              ((unsigned-byte 32) (unsigned-byte 5)))
+  (when (sb!c::constant-lvar-p count)
+    (sb!c::give-up-ir1-transform))
+  '(%primitive fast-ash-left-mod32/unsigned=>unsigned integer count))
+
+(macrolet
+    ((define-modular-backend (fun &optional constantp)
+       (let ((mfun-name (symbolicate fun '-mod32))
+             (modvop (symbolicate 'fast- fun '-mod32/unsigned=>unsigned))
+             (modcvop (symbolicate 'fast- fun 'mod32-c/unsigned=>unsigned))
+             (vop (symbolicate 'fast- fun '/unsigned=>unsigned))
+             (cvop (symbolicate 'fast- fun '-c/unsigned=>unsigned)))
+         `(progn
+            (define-modular-fun ,mfun-name (x y) ,fun :unsigned 32)
+            (define-vop (,modvop ,vop)
+              (:translate ,mfun-name))
+            ,@(when constantp
+                `((define-vop (,modcvop ,cvop)
+                    (:translate ,mfun-name))))))))
+  (define-modular-backend + t)
+  (define-modular-backend - t)
+  (define-modular-backend * t)
+  (define-modular-backend logxor t)
+  (define-modular-backend logeqv)
+  (define-modular-backend lognand)
+  (define-modular-backend lognor)
+  (define-modular-backend logandc1)
+  (define-modular-backend logandc2)
+  (define-modular-backend logorc1)
+  (define-modular-backend logorc2))
+
 ;;;; Binary conditional VOPs:
 
 (define-vop (fast-conditional)
@@ -384,7 +724,7 @@
 
 (define-vop (fast-conditional/fixnum fast-conditional)
   (:args (x :scs (any-reg zero))
-	 (y :scs (any-reg zero)))
+         (y :scs (any-reg zero)))
   (:arg-types tagged-num tagged-num)
   (:note "inline fixnum comparison"))
 
@@ -395,7 +735,7 @@
 
 (define-vop (fast-conditional/signed fast-conditional)
   (:args (x :scs (signed-reg zero))
-	 (y :scs (signed-reg zero)))
+         (y :scs (signed-reg zero)))
   (:arg-types signed-num signed-num)
   (:note "inline (signed-byte 32) comparison"))
 
@@ -406,7 +746,7 @@
 
 (define-vop (fast-conditional/unsigned fast-conditional)
   (:args (x :scs (unsigned-reg zero))
-	 (y :scs (unsigned-reg zero)))
+         (y :scs (unsigned-reg zero)))
   (:arg-types unsigned-num unsigned-num)
   (:note "inline (unsigned-byte 32) comparison"))
 
@@ -415,7 +755,6 @@
   (:arg-types unsigned-num (:constant (unsigned-byte 16)))
   (:info target not-p y))
 
-
 (define-vop (fast-if-</fixnum fast-conditional/fixnum)
   (:translate <)
   (:generator 4
@@ -525,7 +864,7 @@
 
 (define-vop (fast-eql/fixnum fast-conditional)
   (:args (x :scs (any-reg descriptor-reg zero))
-	 (y :scs (any-reg zero)))
+         (y :scs (any-reg zero)))
   (:arg-types tagged-num tagged-num)
   (:note "inline fixnum comparison")
   (:translate eql)
@@ -556,8 +895,8 @@
 (define-vop (merge-bits)
   (:translate merge-bits)
   (:args (shift :scs (signed-reg unsigned-reg))
-	 (prev :scs (unsigned-reg))
-	 (next :scs (unsigned-reg)))
+         (prev :scs (unsigned-reg))
+         (next :scs (unsigned-reg)))
   (:arg-types tagged-num unsigned-num unsigned-num)
   (:temporary (:scs (unsigned-reg) :to (:result 0)) temp)
   (:temporary (:scs (unsigned-reg) :to (:result 0) :target result) res)
@@ -575,69 +914,10 @@
       (emit-label done)
       (move result res))))
 
-
-(define-vop (32bit-logical)
-  (:args (x :scs (unsigned-reg zero))
-	 (y :scs (unsigned-reg zero)))
-  (:arg-types unsigned-num unsigned-num)
-  (:results (r :scs (unsigned-reg)))
-  (:result-types unsigned-num)
-  (:policy :fast-safe))
-
-(define-vop (32bit-logical-not 32bit-logical)
-  (:translate 32bit-logical-not)
-  (:args (x :scs (unsigned-reg zero)))
-  (:arg-types unsigned-num)
-  (:generator 1
-    (inst not r x)))
-
-(define-vop (32bit-logical-and 32bit-logical)
-  (:translate 32bit-logical-and)
-  (:generator 1
-    (inst and r x y)))
-
-(deftransform 32bit-logical-nand ((x y) (* *))
-  '(32bit-logical-not (32bit-logical-and x y)))
-
-(define-vop (32bit-logical-or 32bit-logical)
-  (:translate 32bit-logical-or)
-  (:generator 1
-    (inst or r x y)))
-
-(deftransform 32bit-logical-nor ((x y) (* *))
-  '(32bit-logical-not (32bit-logical-or x y)))
-
-(define-vop (32bit-logical-xor 32bit-logical)
-  (:translate 32bit-logical-xor)
-  (:generator 1
-    (inst xor r x y)))
-
-(define-vop (32bit-logical-eqv 32bit-logical)
-  (:translate 32bit-logical-eqv)
-  (:generator 1
-    (inst eqv r x y)))
-
-(define-vop (32bit-logical-orc2 32bit-logical)
-  (:translate 32bit-logical-orc2)
-  (:generator 1
-    (inst orc r x y)))
-
-(deftransform 32bit-logical-orc1 ((x y) (* *))
-  '(32bit-logical-orc2 y x))
-
-(define-vop (32bit-logical-andc2 32bit-logical)
-  (:translate 32bit-logical-andc2)
-  (:generator 1
-    (inst andc r x y)))
-
-(deftransform 32bit-logical-andc1 ((x y) (* *))
-  '(32bit-logical-andc2 y x))
-
-
 (define-vop (shift-towards-someplace)
   (:policy :fast-safe)
   (:args (num :scs (unsigned-reg))
-	 (amount :scs (signed-reg)))
+         (amount :scs (signed-reg)))
   (:arg-types unsigned-num tagged-num)
   (:results (r :scs (unsigned-reg)))
   (:result-types unsigned-num))
@@ -655,38 +935,35 @@
   (:generator 1
     (inst rlwinm amount amount 0 27 31)
     (inst srw r num amount)))
-
-
-
 
 ;;;; Bignum stuff.
 
 (define-vop (bignum-length get-header-data)
-  (:translate sb!bignum::%bignum-length)
+  (:translate sb!bignum:%bignum-length)
   (:policy :fast-safe))
 
 (define-vop (bignum-set-length set-header-data)
-  (:translate sb!bignum::%bignum-set-length)
+  (:translate sb!bignum:%bignum-set-length)
   (:policy :fast-safe))
 
 (define-vop (bignum-ref word-index-ref)
-  (:variant sb!vm:bignum-digits-offset sb!vm:other-pointer-lowtag)
-  (:translate sb!bignum::%bignum-ref)
+  (:variant bignum-digits-offset other-pointer-lowtag)
+  (:translate sb!bignum:%bignum-ref)
   (:results (value :scs (unsigned-reg)))
   (:result-types unsigned-num))
 
 (define-vop (bignum-set word-index-set)
-  (:variant sb!vm:bignum-digits-offset sb!vm:other-pointer-lowtag)
-  (:translate sb!bignum::%bignum-set)
+  (:variant bignum-digits-offset other-pointer-lowtag)
+  (:translate sb!bignum:%bignum-set)
   (:args (object :scs (descriptor-reg))
-	 (index :scs (any-reg immediate zero))
-	 (value :scs (unsigned-reg)))
+         (index :scs (any-reg immediate zero))
+         (value :scs (unsigned-reg)))
   (:arg-types t positive-fixnum unsigned-num)
   (:results (result :scs (unsigned-reg)))
   (:result-types unsigned-num))
 
 (define-vop (digit-0-or-plus)
-  (:translate sb!bignum::%digit-0-or-plusp)
+  (:translate sb!bignum:%digit-0-or-plusp)
   (:policy :fast-safe)
   (:args (digit :scs (unsigned-reg)))
   (:arg-types unsigned-num)
@@ -700,15 +977,15 @@
       (emit-label done))))
 
 (define-vop (add-w/carry)
-  (:translate sb!bignum::%add-with-carry)
+  (:translate sb!bignum:%add-with-carry)
   (:policy :fast-safe)
   (:args (a :scs (unsigned-reg))
-	 (b :scs (unsigned-reg))
-	 (c :scs (any-reg)))
+         (b :scs (unsigned-reg))
+         (c :scs (any-reg)))
   (:arg-types unsigned-num unsigned-num positive-fixnum)
   (:temporary (:scs (unsigned-reg)) temp)
   (:results (result :scs (unsigned-reg))
-	    (carry :scs (unsigned-reg)))
+            (carry :scs (unsigned-reg)))
   (:result-types unsigned-num positive-fixnum)
   (:generator 3
     (inst addic temp c -1)
@@ -716,15 +993,15 @@
     (inst addze carry zero-tn)))
 
 (define-vop (sub-w/borrow)
-  (:translate sb!bignum::%subtract-with-borrow)
+  (:translate sb!bignum:%subtract-with-borrow)
   (:policy :fast-safe)
   (:args (a :scs (unsigned-reg))
-	 (b :scs (unsigned-reg))
-	 (c :scs (any-reg)))
+         (b :scs (unsigned-reg))
+         (c :scs (any-reg)))
   (:arg-types unsigned-num unsigned-num positive-fixnum)
   (:temporary (:scs (unsigned-reg)) temp)
   (:results (result :scs (unsigned-reg))
-	    (borrow :scs (unsigned-reg)))
+            (borrow :scs (unsigned-reg)))
   (:result-types unsigned-num positive-fixnum)
   (:generator 4
     (inst addic temp c -1)
@@ -732,17 +1009,17 @@
     (inst addze borrow zero-tn)))
 
 (define-vop (bignum-mult-and-add-3-arg)
-  (:translate sb!bignum::%multiply-and-add)
+  (:translate sb!bignum:%multiply-and-add)
   (:policy :fast-safe)
   (:args (x :scs (unsigned-reg))
-	 (y :scs (unsigned-reg))
-	 (carry-in :scs (unsigned-reg) :to (:eval 1)))
+         (y :scs (unsigned-reg))
+         (carry-in :scs (unsigned-reg) :to (:eval 1)))
   (:arg-types unsigned-num unsigned-num unsigned-num)
   (:temporary (:scs (unsigned-reg) :to (:result 0) :target hi) hi-temp)
   (:temporary (:scs (unsigned-reg) :from (:eval 0) :to (:result 1)
-		    :target lo) lo-temp)
+                    :target lo) lo-temp)
   (:results (hi :scs (unsigned-reg))
-	    (lo :scs (unsigned-reg)))
+            (lo :scs (unsigned-reg)))
   (:result-types unsigned-num unsigned-num)
   (:generator 40
     (inst mulhwu hi-temp x y)
@@ -751,18 +1028,18 @@
     (inst addze hi hi-temp)))
 
 (define-vop (bignum-mult-and-add-4-arg)
-  (:translate sb!bignum::%multiply-and-add)
+  (:translate sb!bignum:%multiply-and-add)
   (:policy :fast-safe)
   (:args (x :scs (unsigned-reg))
-	 (y :scs (unsigned-reg))
-	 (prev :scs (unsigned-reg) :to (:eval 1))
-	 (carry-in :scs (unsigned-reg) :to (:eval 1)))
+         (y :scs (unsigned-reg))
+         (prev :scs (unsigned-reg) :to (:eval 1))
+         (carry-in :scs (unsigned-reg) :to (:eval 1)))
   (:arg-types unsigned-num unsigned-num unsigned-num unsigned-num)
   (:temporary (:scs (unsigned-reg) :to (:result 0) :target hi) hi-temp)
   (:temporary (:scs (unsigned-reg) :from (:eval 0) :to (:result 1)
-		    :target lo) lo-temp)
+                    :target lo) lo-temp)
   (:results (hi :scs (unsigned-reg))
-	    (lo :scs (unsigned-reg)))
+            (lo :scs (unsigned-reg)))
   (:result-types unsigned-num unsigned-num)
   (:generator 40
     (inst mulhwu hi-temp x y)
@@ -773,30 +1050,23 @@
     (inst addze hi hi-temp)))
 
 (define-vop (bignum-mult)
-  (:translate sb!bignum::%multiply)
+  (:translate sb!bignum:%multiply)
   (:policy :fast-safe)
-  (:args (x :scs (unsigned-reg) :to (:result 1))
-	 (y :scs (unsigned-reg) :to (:result 1)))
+  (:args (x :scs (unsigned-reg) :to (:eval 1))
+         (y :scs (unsigned-reg) :to (:eval 1)))
   (:arg-types unsigned-num unsigned-num)
-  (:results (hi :scs (unsigned-reg))
-	    (lo :scs (unsigned-reg)))
+  (:results (hi :scs (unsigned-reg) :from (:eval 1))
+            (lo :scs (unsigned-reg) :from (:eval 0)))
   (:result-types unsigned-num unsigned-num)
   (:generator 40
     (inst mullw lo x y)
     (inst mulhwu hi x y)))
 
-(define-vop (bignum-lognot)
-  (:translate sb!bignum::%lognot)
-  (:policy :fast-safe)
-  (:args (x :scs (unsigned-reg)))
-  (:arg-types unsigned-num)
-  (:results (r :scs (unsigned-reg)))
-  (:result-types unsigned-num)
-  (:generator 1
-    (inst not r x)))
+(define-vop (bignum-lognot lognot-mod32/unsigned=>unsigned)
+  (:translate sb!bignum:%lognot))
 
 (define-vop (fixnum-to-digit)
-  (:translate sb!bignum::%fixnum-to-digit)
+  (:translate sb!bignum:%fixnum-to-digit)
   (:policy :fast-safe)
   (:args (fixnum :scs (any-reg)))
   (:arg-types tagged-num)
@@ -807,52 +1077,52 @@
 
 
 (define-vop (bignum-floor)
-  (:translate sb!bignum::%floor)
+  (:translate sb!bignum:%floor)
   (:policy :fast-safe)
   (:args (num-high :scs (unsigned-reg) :target rem)
-	 (num-low :scs (unsigned-reg) :target rem-low)
-	 (denom :scs (unsigned-reg) :to (:eval 1)))
+         (num-low :scs (unsigned-reg) :target rem-low)
+         (denom :scs (unsigned-reg) :to (:eval 1)))
   (:arg-types unsigned-num unsigned-num unsigned-num)
   (:temporary (:scs (unsigned-reg) :from (:argument 1)) rem-low)
   (:temporary (:scs (unsigned-reg) :from (:eval 0)) temp)
   (:results (quo :scs (unsigned-reg) :from (:eval 0))
-	    (rem :scs (unsigned-reg) :from (:argument 0)))
+            (rem :scs (unsigned-reg) :from (:argument 0)))
   (:result-types unsigned-num unsigned-num)
   (:generator 325 ; number of inst assuming targeting works.
     (move rem num-high)
     (move rem-low num-low)
     (flet ((maybe-subtract (&optional (guess temp))
-	     (inst subi temp guess 1)
-	     (inst and temp temp denom)
-	     (inst sub rem rem temp))
-	   (sltu (res x y)
-	     (inst subfc res y x)
-	     (inst subfe res res res)
-	     (inst neg res res)))
+             (inst subi temp guess 1)
+             (inst and temp temp denom)
+             (inst sub rem rem temp))
+           (sltu (res x y)
+             (inst subfc res y x)
+             (inst subfe res res res)
+             (inst neg res res)))
       (sltu quo rem denom)
       (maybe-subtract quo)
       (dotimes (i 32)
-	(inst slwi rem rem 1)
-	(inst srwi temp rem-low 31)
-	(inst or rem rem temp)
-	(inst slwi rem-low rem-low 1)
-	(sltu temp rem denom)
-	(inst slwi quo quo 1)
-	(inst or quo quo temp)
-	(maybe-subtract)))
+        (inst slwi rem rem 1)
+        (inst srwi temp rem-low 31)
+        (inst or rem rem temp)
+        (inst slwi rem-low rem-low 1)
+        (sltu temp rem denom)
+        (inst slwi quo quo 1)
+        (inst or quo quo temp)
+        (maybe-subtract)))
     (inst not quo quo)))
 
 #|
 
 (define-vop (bignum-floor)
-  (:translate sb!bignum::%floor)
+  (:translate sb!bignum:%floor)
   (:policy :fast-safe)
   (:args (div-high :scs (unsigned-reg) :target rem)
-	 (div-low :scs (unsigned-reg) :target quo)
-	 (divisor :scs (unsigned-reg)))
+         (div-low :scs (unsigned-reg) :target quo)
+         (divisor :scs (unsigned-reg)))
   (:arg-types unsigned-num unsigned-num unsigned-num)
   (:results (quo :scs (unsigned-reg) :from (:argument 1))
-	    (rem :scs (unsigned-reg) :from (:argument 0)))
+            (rem :scs (unsigned-reg) :from (:argument 0)))
   (:result-types unsigned-num unsigned-num)
   (:generator 300
     (inst mtmq div-low)
@@ -861,7 +1131,7 @@
 |#
 
 (define-vop (signify-digit)
-  (:translate sb!bignum::%fixnum-digit-with-correct-sign)
+  (:translate sb!bignum:%fixnum-digit-with-correct-sign)
   (:policy :fast-safe)
   (:args (digit :scs (unsigned-reg) :target res))
   (:arg-types unsigned-num)
@@ -876,10 +1146,10 @@
 
 
 (define-vop (digit-ashr)
-  (:translate sb!bignum::%ashr)
+  (:translate sb!bignum:%ashr)
   (:policy :fast-safe)
   (:args (digit :scs (unsigned-reg))
-	 (count :scs (unsigned-reg)))
+         (count :scs (unsigned-reg)))
   (:arg-types unsigned-num positive-fixnum)
   (:results (result :scs (unsigned-reg)))
   (:result-types unsigned-num)
@@ -887,12 +1157,12 @@
     (inst sraw result digit count)))
 
 (define-vop (digit-lshr digit-ashr)
-  (:translate sb!bignum::%digit-logical-shift-right)
+  (:translate sb!bignum:%digit-logical-shift-right)
   (:generator 1
     (inst srw result digit count)))
 
 (define-vop (digit-ashl digit-ashr)
-  (:translate sb!bignum::%ashl)
+  (:translate sb!bignum:%ashl)
   (:generator 1
     (inst slw result digit count)))
 
@@ -919,3 +1189,26 @@
 (define-static-fun two-arg-and (x y) :translate logand)
 (define-static-fun two-arg-ior (x y) :translate logior)
 (define-static-fun two-arg-xor (x y) :translate logxor)
+(define-static-fun two-arg-eqv (x y) :translate logeqv)
+
+(in-package "SB!C")
+
+(deftransform * ((x y)
+                 ((unsigned-byte 32) (constant-arg (unsigned-byte 32)))
+                 (unsigned-byte 32))
+  "recode as shifts and adds"
+  (let ((y (lvar-value y)))
+    (multiple-value-bind (result adds shifts)
+        (ub32-strength-reduce-constant-multiply 'x y)
+      (cond
+       ((typep y '(signed-byte 16))
+        ;; a mulli instruction has a latency of 5.
+        (when (> (+ adds shifts) 4)
+          (give-up-ir1-transform)))
+       (t
+        ;; a mullw instruction also has a latency of 5, plus two
+        ;; instructions (in general) to load the immediate into a
+        ;; register.
+        (when (> (+ adds shifts) 6)
+          (give-up-ir1-transform))))
+      (or result 0))))