+;;;; %LDB
+
+(defknown %%ldb (integer unsigned-byte unsigned-byte) unsigned-byte
+ (movable foldable flushable always-translatable))
+
+;;; only for constant folding within the compiler
+(defun %%ldb (integer size posn)
+ (sb!kernel::%ldb size posn integer))
+
+(define-vop (ldb-c/fixnum)
+ (:translate %%ldb)
+ (:args (x :scs (any-reg)))
+ (:arg-types tagged-num (:constant (integer 1 29)) (:constant (integer 0 29)))
+ (:info size posn)
+ (:results (res :scs (any-reg)))
+ (:result-types tagged-num)
+ (:policy :fast-safe)
+ (:generator 2
+ (inst rlwinm res x
+ (mod (- 32 posn) 32) ; effectively rotate right
+ (- 32 size n-fixnum-tag-bits)
+ (- 31 n-fixnum-tag-bits))))
+
+(define-vop (ldb-c/signed)
+ (:translate %%ldb)
+ (:args (x :scs (signed-reg)))
+ (:arg-types signed-num (:constant (integer 1 29)) (:constant (integer 0 29)))
+ (:info size posn)
+ (:results (res :scs (any-reg)))
+ (:result-types tagged-num)
+ (:policy :fast-safe)
+ (:generator 3
+ (inst rlwinm res x
+ (mod (- (+ 32 n-fixnum-tag-bits) posn) 32)
+ (- 32 size n-fixnum-tag-bits)
+ (- 31 n-fixnum-tag-bits))))
+
+(define-vop (ldb-c/unsigned)
+ (:translate %%ldb)
+ (:args (x :scs (unsigned-reg)))
+ (:arg-types unsigned-num (:constant (integer 1 29)) (:constant (integer 0 29)))
+ (:info size posn)
+ (:results (res :scs (any-reg)))
+ (:result-types tagged-num)
+ (:policy :fast-safe)
+ (:generator 3
+ (inst rlwinm res x
+ (mod (- (+ 32 n-fixnum-tag-bits) posn) 32)
+ (- 32 size n-fixnum-tag-bits)
+ (- 31 n-fixnum-tag-bits))))
+
+\f
+;;;; 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))
+\f