;;;; files for more information.
(in-package "SB!VM")
-
-(file-comment
- "$Header$")
\f
;;;; unary operations
(move r x)
(inst add r y)))))
+
+;;;; Special logand cases: (logand signed unsigned) => unsigned
+
+(define-vop (fast-logand/signed-unsigned=>unsigned
+ fast-logand/unsigned=>unsigned)
+ (:args (x :target r :scs (signed-reg)
+ :load-if (not (and (sc-is x signed-stack)
+ (sc-is y unsigned-reg)
+ (sc-is r unsigned-stack)
+ (location= x r))))
+ (y :scs (unsigned-reg unsigned-stack)))
+ (:arg-types signed-num unsigned-num))
+
+(define-vop (fast-logand-c/signed-unsigned=>unsigned
+ fast-logand-c/unsigned=>unsigned)
+ (:args (x :target r :scs (signed-reg signed-stack)))
+ (:arg-types signed-num (:constant (unsigned-byte 32))))
+
+(define-vop (fast-logand/unsigned-signed=>unsigned
+ fast-logand/unsigned=>unsigned)
+ (:args (x :target r :scs (unsigned-reg)
+ :load-if (not (and (sc-is x unsigned-stack)
+ (sc-is y signed-reg)
+ (sc-is r unsigned-stack)
+ (location= x r))))
+ (y :scs (signed-reg signed-stack)))
+ (:arg-types unsigned-num signed-num))
+\f
+
(define-vop (fast-+-c/signed=>signed fast-safe-arith-op)
(:translate +)
(:args (x :target r :scs (signed-reg signed-stack)))
;; The result-type ensures us that this shift will not overflow.
(inst shl result :cl)))
-(define-vop (fast-ash-c)
+(define-vop (fast-ash-c/signed=>signed)
(:translate ash)
(:policy :fast-safe)
- (:args (number :scs (signed-reg unsigned-reg) :target result
- :load-if (not (and (sc-is number signed-stack unsigned-stack)
- (sc-is result signed-stack unsigned-stack)
+ (:args (number :scs (signed-reg) :target result
+ :load-if (not (and (sc-is number signed-stack)
+ (sc-is result signed-stack)
(location= number result)))))
(:info amount)
- (:arg-types (:or signed-num unsigned-num) (:constant integer))
- (:results (result :scs (signed-reg unsigned-reg)
- :load-if (not
- (and (sc-is number signed-stack unsigned-stack)
- (sc-is result signed-stack unsigned-stack)
- (location= number result)))))
- (:result-types (:or signed-num unsigned-num))
+ (:arg-types signed-num (:constant integer))
+ (:results (result :scs (signed-reg)
+ :load-if (not (and (sc-is number signed-stack)
+ (sc-is result signed-stack)
+ (location= number result)))))
+ (:result-types signed-num)
(:note "inline ASH")
(:generator 3
(cond ((and (= amount 1) (not (location= number result)))
(inst lea result (make-ea :dword :index number :scale 8)))
(t
(move result number)
- (cond ((plusp amount)
- ;; We don't have to worry about overflow because of the
- ;; result type restriction.
- (inst shl result amount))
- ((sc-is number signed-reg signed-stack)
- ;; If the amount is greater than 31, only shift by 31. We
- ;; have to do this because the shift instructions only look
- ;; at the low five bits of the result.
- (inst sar result (min 31 (- amount))))
- (t
- (inst shr result (min 31 (- amount)))))))))
+ (cond ((plusp amount) (inst shl result amount))
+ (t (inst sar result (min 31 (- amount)))))))))
-(define-vop (fast-ash-left)
+(define-vop (fast-ash-c/unsigned=>unsigned)
(:translate ash)
- (:args (number :scs (signed-reg unsigned-reg) :target result
- :load-if (not (and (sc-is number signed-stack unsigned-stack)
- (sc-is result signed-stack unsigned-stack)
+ (:policy :fast-safe)
+ (:args (number :scs (unsigned-reg) :target result
+ :load-if (not (and (sc-is number unsigned-stack)
+ (sc-is result unsigned-stack)
+ (location= number result)))))
+ (:info amount)
+ (:arg-types unsigned-num (:constant integer))
+ (:results (result :scs (unsigned-reg)
+ :load-if (not (and (sc-is number unsigned-stack)
+ (sc-is result unsigned-stack)
+ (location= number result)))))
+ (:result-types unsigned-num)
+ (:note "inline ASH")
+ (:generator 3
+ (cond ((and (= amount 1) (not (location= number result)))
+ (inst lea result (make-ea :dword :index number :scale 2)))
+ ((and (= amount 2) (not (location= number result)))
+ (inst lea result (make-ea :dword :index number :scale 4)))
+ ((and (= amount 3) (not (location= number result)))
+ (inst lea result (make-ea :dword :index number :scale 8)))
+ (t
+ (move result number)
+ (cond ((plusp amount) (inst shl result amount))
+ ((< amount -31) (inst xor result result))
+ (t (inst shr result (- amount))))))))
+
+(define-vop (fast-ash-left/signed)
+ (:translate ash)
+ (:args (number :scs (signed-reg) :target result
+ :load-if (not (and (sc-is number signed-stack)
+ (sc-is result signed-stack)
(location= number result))))
(amount :scs (unsigned-reg) :target ecx))
- (:arg-types (:or signed-num unsigned-num) positive-fixnum)
+ (:arg-types signed-num positive-fixnum)
(:temporary (:sc unsigned-reg :offset ecx-offset :from (:argument 1)) ecx)
- (:results (result :scs (signed-reg unsigned-reg) :from (:argument 0)
- :load-if (not
- (and (sc-is number signed-stack unsigned-stack)
- (sc-is result signed-stack unsigned-stack)
- (location= number result)))))
- (:result-types (:or signed-num unsigned-num))
+ (:results (result :scs (signed-reg) :from (:argument 0)
+ :load-if (not (and (sc-is number signed-stack)
+ (sc-is result signed-stack)
+ (location= number result)))))
+ (:result-types signed-num)
(:policy :fast-safe)
(:note "inline ASH")
(:generator 4
(move result number)
(move ecx amount)
- ;; The result-type ensures us that this shift will not overflow.
(inst shl result :cl)))
-(define-vop (fast-ash)
+(define-vop (fast-ash-left/unsigned)
(:translate ash)
+ (:args (number :scs (unsigned-reg) :target result
+ :load-if (not (and (sc-is number unsigned-stack)
+ (sc-is result unsigned-stack)
+ (location= number result))))
+ (amount :scs (unsigned-reg) :target ecx))
+ (:arg-types unsigned-num positive-fixnum)
+ (:temporary (:sc unsigned-reg :offset ecx-offset :from (:argument 1)) ecx)
+ (:results (result :scs (unsigned-reg) :from (:argument 0)
+ :load-if (not (and (sc-is number unsigned-stack)
+ (sc-is result unsigned-stack)
+ (location= number result)))))
+ (:result-types unsigned-num)
(:policy :fast-safe)
- (:args (number :scs (signed-reg unsigned-reg) :target result)
+ (:note "inline ASH")
+ (:generator 4
+ (move result number)
+ (move ecx amount)
+ (inst shl result :cl)))
+
+(define-vop (fast-ash/signed=>signed)
+ (:translate ash)
+ (:policy :fast-safe)
+ (:args (number :scs (signed-reg) :target result)
(amount :scs (signed-reg) :target ecx))
- (:arg-types (:or signed-num unsigned-num) signed-num)
- (:results (result :scs (signed-reg unsigned-reg) :from (:argument 0)))
- (:result-types (:or signed-num unsigned-num))
+ (:arg-types signed-num signed-num)
+ (:results (result :scs (signed-reg) :from (:argument 0)))
+ (:result-types signed-num)
(:temporary (:sc signed-reg :offset ecx-offset :from (:argument 1)) ecx)
(:note "inline ASH")
(:generator 5
(move result number)
- (move ecx amount)
+ (move ecx amount)
(inst or ecx ecx)
(inst jmp :ns positive)
(inst neg ecx)
(inst jmp :be okay)
(inst mov ecx 31)
OKAY
- (sc-case number
- (signed-reg (inst sar result :cl))
- (unsigned-reg (inst shr result :cl)))
+ (inst sar result :cl)
+ (inst jmp done)
+
+ POSITIVE
+ ;; The result-type ensures us that this shift will not overflow.
+ (inst shl result :cl)
+
+ DONE))
+
+(define-vop (fast-ash/unsigned=>unsigned)
+ (:translate ash)
+ (:policy :fast-safe)
+ (:args (number :scs (unsigned-reg) :target result)
+ (amount :scs (signed-reg) :target ecx))
+ (:arg-types unsigned-num signed-num)
+ (:results (result :scs (unsigned-reg) :from (:argument 0)))
+ (:result-types unsigned-num)
+ (:temporary (:sc signed-reg :offset ecx-offset :from (:argument 1)) ecx)
+ (:note "inline ASH")
+ (:generator 5
+ (move result number)
+ (move ecx amount)
+ (inst or ecx ecx)
+ (inst jmp :ns positive)
+ (inst neg ecx)
+ (inst cmp ecx 31)
+ (inst jmp :be okay)
+ (inst xor result result)
+ (inst jmp done)
+ OKAY
+ (inst shr result :cl)
(inst jmp done)
POSITIVE
(inst shl result :cl)
DONE))
+
+;;; FIXME: before making knowledge of this too public, it needs to be
+;;; fixed so that it's actually _faster_ than the non-CMOV version; at
+;;; least on my Celeron-XXX laptop, this version is marginally slower
+;;; than the above version with branches. -- CSR, 2003-09-04
+(define-vop (fast-cmov-ash/unsigned=>unsigned)
+ (:translate ash)
+ (:policy :fast-safe)
+ (:args (number :scs (unsigned-reg) :target result)
+ (amount :scs (signed-reg) :target ecx))
+ (:arg-types unsigned-num signed-num)
+ (:results (result :scs (unsigned-reg) :from (:argument 0)))
+ (:result-types unsigned-num)
+ (:temporary (:sc signed-reg :offset ecx-offset :from (:argument 1)) ecx)
+ (:temporary (:sc any-reg :from (:eval 0) :to (:eval 1)) zero)
+ (:note "inline ASH")
+ (:guard (member :cmov *backend-subfeatures*))
+ (:generator 4
+ (move result number)
+ (move ecx amount)
+ (inst or ecx ecx)
+ (inst jmp :ns positive)
+ (inst neg ecx)
+ (inst xor zero zero)
+ (inst shr result :cl)
+ (inst cmp ecx 31)
+ (inst cmov :nbe result zero)
+ (inst jmp done)
+
+ POSITIVE
+ ;; The result-type ensures us that this shift will not overflow.
+ (inst shl result :cl)
+
+ DONE))
\f
;;; Note: documentation for this function is wrong - rtfm
(define-vop (signed-byte-32-len)
(:policy :fast-safe)
(:args (arg :scs (signed-reg) :target res))
(:arg-types signed-num)
- (:results (res :scs (any-reg)))
- (:result-types positive-fixnum)
- (:generator 30
+ (:results (res :scs (unsigned-reg)))
+ (:result-types unsigned-num)
+ (:generator 28
(move res arg)
(inst cmp res 0)
(inst jmp :ge POS)
(inst bsr res res)
(inst jmp :z zero)
(inst inc res)
- (inst shl res 2)
+ (inst jmp done)
+ ZERO
+ (inst xor res res)
+ DONE))
+
+(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 26
+ (inst bsr res arg)
+ (inst jmp :z zero)
+ (inst inc res)
(inst jmp done)
ZERO
(inst xor res res)
(inst and result #x0000ffff)
(inst and temp #x0000ffff)
(inst add result temp)))
-
-
\f
;;;; binary conditional VOPs
(macrolet ((define-conditional-vop (tran cond unsigned not-cond not-unsigned)
`(progn
,@(mapcar
- #'(lambda (suffix cost signed)
- `(define-vop (;; FIXME: These could be done more
- ;; cleanly with SYMBOLICATE.
- ,(intern (format nil "~:@(FAST-IF-~A~A~)"
- tran suffix))
- ,(intern
- (format nil "~:@(FAST-CONDITIONAL~A~)"
- suffix)))
- (:translate ,tran)
- (:generator ,cost
- (inst cmp x
- ,(if (eq suffix '-c/fixnum)
- '(fixnumize y)
- 'y))
- (inst jmp (if not-p
- ,(if signed
- not-cond
- not-unsigned)
- ,(if signed
- cond
- unsigned))
- target))))
+ (lambda (suffix cost signed)
+ `(define-vop (;; FIXME: These could be done more
+ ;; cleanly with SYMBOLICATE.
+ ,(intern (format nil "~:@(FAST-IF-~A~A~)"
+ tran suffix))
+ ,(intern
+ (format nil "~:@(FAST-CONDITIONAL~A~)"
+ suffix)))
+ (:translate ,tran)
+ (:generator ,cost
+ (inst cmp x
+ ,(if (eq suffix '-c/fixnum)
+ '(fixnumize y)
+ 'y))
+ (inst jmp (if not-p
+ ,(if signed
+ not-cond
+ not-unsigned)
+ ,(if signed
+ cond
+ unsigned))
+ target))))
'(/fixnum -c/fixnum /signed -c/signed /unsigned -c/unsigned)
'(4 3 6 5 6 5)
'(t t t t nil nil)))))
(move result prev)
(inst shrd result next :cl)))
-(define-vop (32bit-logical)
- (:args (x :scs (unsigned-reg) :target r
- :load-if (not (and (sc-is x unsigned-stack)
- (sc-is r unsigned-stack)
- (location= x r))))
- (y :scs (unsigned-reg)
- :load-if (or (not (sc-is y unsigned-stack))
- (and (sc-is x unsigned-stack)
- (sc-is y unsigned-stack)
- (location= x r)))))
- (:arg-types unsigned-num unsigned-num)
- (:results (r :scs (unsigned-reg)
- :from (:argument 0)
- :load-if (not (and (sc-is x unsigned-stack)
- (sc-is r unsigned-stack)
- (location= x r)))))
- (:result-types unsigned-num)
- (:policy :fast-safe))
+(define-source-transform 32bit-logical-not (x)
+ `(logand (lognot (the (unsigned-byte 32) ,x)) #.(1- (ash 1 32))))
-(define-vop (32bit-logical-not)
- (:translate 32bit-logical-not)
- (:args (x :scs (unsigned-reg) :target r
- :load-if (not (and (sc-is x unsigned-stack)
- (sc-is r unsigned-stack)
- (location= x r)))))
- (:arg-types unsigned-num)
- (:results (r :scs (unsigned-reg)
- :load-if (not (and (sc-is x unsigned-stack)
- (sc-is r unsigned-stack)
- (location= x r)))))
- (:result-types unsigned-num)
- (:policy :fast-safe)
- (:generator 1
- (move r x)
- (inst not r)))
+(deftransform 32bit-logical-and ((x y))
+ '(logand x y))
-(define-vop (32bit-logical-and 32bit-logical)
- (:translate 32bit-logical-and)
- (:generator 1
- (move r x)
- (inst and r y)))
-
-(def-source-transform 32bit-logical-nand (x y)
+(define-source-transform 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
- (move r x)
- (inst or r y)))
+(deftransform 32bit-logical-or ((x y))
+ '(logior x y))
-(def-source-transform 32bit-logical-nor (x y)
+(define-source-transform 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
- (move r x)
- (inst xor r y)))
+(deftransform 32bit-logical-xor ((x y))
+ '(logxor x y))
-(def-source-transform 32bit-logical-eqv (x y)
+(define-source-transform 32bit-logical-eqv (x y)
`(32bit-logical-not (32bit-logical-xor ,x ,y)))
-(def-source-transform 32bit-logical-orc1 (x y)
+(define-source-transform 32bit-logical-orc1 (x y)
`(32bit-logical-or (32bit-logical-not ,x) ,y))
-(def-source-transform 32bit-logical-orc2 (x y)
+(define-source-transform 32bit-logical-orc2 (x y)
`(32bit-logical-or ,x (32bit-logical-not ,y)))
-(def-source-transform 32bit-logical-andc1 (x y)
+(define-source-transform 32bit-logical-andc1 (x y)
`(32bit-logical-and (32bit-logical-not ,x) ,y))
-(def-source-transform 32bit-logical-andc2 (x y)
+(define-source-transform 32bit-logical-andc2 (x y)
`(32bit-logical-and ,x (32bit-logical-not ,y)))
;;; Only the lower 5 bits of the shift amount are significant.
(move ecx amount)
(inst shl r :cl)))
\f
+;;;; Modular functions
+
+(define-modular-fun +-mod32 (x y) + 32)
+(define-vop (fast-+-mod32/unsigned=>unsigned fast-+/unsigned=>unsigned)
+ (:translate +-mod32))
+(define-vop (fast-+-mod32-c/unsigned=>unsigned fast-+-c/unsigned=>unsigned)
+ (:translate +-mod32))
+
+;;; logical operations
+(define-modular-fun lognot-mod32 (x) lognot 32)
+(define-vop (lognot-mod32/unsigned=>unsigned)
+ (:translate lognot-mod32)
+ (:args (x :scs (unsigned-reg unsigned-stack) :target r
+ :load-if (not (and (sc-is x unsigned-stack)
+ (sc-is r unsigned-stack)
+ (location= x r)))))
+ (:arg-types unsigned-num)
+ (:results (r :scs (unsigned-reg)
+ :load-if (not (and (sc-is x unsigned-stack)
+ (sc-is r unsigned-stack)
+ (location= x r)))))
+ (:result-types unsigned-num)
+ (:policy :fast-safe)
+ (:generator 1
+ (move r x)
+ (inst not r)))
+
+(define-modular-fun logxor-mod32 (x y) logxor 32)
+(define-vop (fast-logxor-mod32/unsigned=>unsigned
+ fast-logxor/unsigned=>unsigned)
+ (:translate logxor-mod32))
+(define-vop (fast-logxor-mod32-c/unsigned=>unsigned
+ fast-logxor-c/unsigned=>unsigned)
+ (:translate logxor-mod32))
+\f
;;;; bignum stuff
(define-vop (bignum-length get-header-data)
(:translate sb!bignum::%bignum-set-length)
(:policy :fast-safe))
-(define-full-reffer bignum-ref * bignum-digits-offset other-pointer-type
+(define-full-reffer bignum-ref * bignum-digits-offset other-pointer-lowtag
(unsigned-reg) unsigned-num sb!bignum::%bignum-ref)
-(define-full-setter bignum-set * bignum-digits-offset other-pointer-type
+(define-full-setter bignum-set * bignum-digits-offset other-pointer-lowtag
(unsigned-reg) unsigned-num sb!bignum::%bignum-set)
(define-vop (digit-0-or-plus)
(move hi edx)
(move lo eax)))
-(define-vop (bignum-lognot)
- (:translate sb!bignum::%lognot)
- (:policy :fast-safe)
- (:args (x :scs (unsigned-reg unsigned-stack) :target r))
- (:arg-types unsigned-num)
- (:results (r :scs (unsigned-reg)
- :load-if (not (location= x r))))
- (:result-types unsigned-num)
- (:generator 1
- (move r x)
- (inst not r)))
+(define-vop (bignum-lognot lognot-mod32/unsigned=>unsigned)
+ (:translate sb!bignum::%lognot))
(define-vop (fixnum-to-digit)
(:translate sb!bignum::%fixnum-to-digit)
\f
;;;; static functions
-(define-static-function two-arg-/ (x y) :translate /)
+(define-static-fun two-arg-/ (x y) :translate /)
-(define-static-function two-arg-gcd (x y) :translate gcd)
-(define-static-function two-arg-lcm (x y) :translate lcm)
+(define-static-fun two-arg-gcd (x y) :translate gcd)
+(define-static-fun two-arg-lcm (x y) :translate lcm)
-(define-static-function two-arg-and (x y) :translate logand)
-(define-static-function two-arg-ior (x y) :translate logior)
-(define-static-function two-arg-xor (x y) :translate logxor)
+(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)
\f
;;; Support for the Mersenne Twister, MT19937, random number generator
(:result-types unsigned-num)
(:generator 50
(inst mov k (make-ea :dword :base state
- :disp (- (* (+ 2 sb!vm:vector-data-offset)
- sb!vm:word-bytes)
- sb!vm:other-pointer-type)))
+ :disp (- (* (+ 2 vector-data-offset)
+ n-word-bytes)
+ other-pointer-lowtag)))
(inst cmp k 624)
(inst jmp :ne no-update)
(inst mov tmp state) ; The state is passed in EAX.
NO-UPDATE
;; y = ptgfsr[k++];
(inst mov y (make-ea :dword :base state :index k :scale 4
- :disp (- (* (+ 3 sb!vm:vector-data-offset)
- sb!vm:word-bytes)
- sb!vm:other-pointer-type)))
+ :disp (- (* (+ 3 vector-data-offset)
+ n-word-bytes)
+ other-pointer-lowtag)))
;; y ^= (y >> 11);
(inst shr y 11)
(inst xor y (make-ea :dword :base state :index k :scale 4
- :disp (- (* (+ 3 sb!vm:vector-data-offset)
- sb!vm:word-bytes)
- sb!vm:other-pointer-type)))
+ :disp (- (* (+ 3 vector-data-offset)
+ n-word-bytes)
+ other-pointer-lowtag)))
;; y ^= (y << 7) & #x9d2c5680
(inst mov tmp y)
(inst inc k)
(inst shl tmp 7)
(inst mov (make-ea :dword :base state
- :disp (- (* (+ 2 sb!vm:vector-data-offset)
- sb!vm:word-bytes)
- sb!vm:other-pointer-type))
+ :disp (- (* (+ 2 vector-data-offset)
+ n-word-bytes)
+ other-pointer-lowtag))
k)
(inst and tmp #x9d2c5680)
(inst xor y tmp)
(inst mov tmp y)
(inst shr tmp 18)
(inst xor y tmp)))
+
+(in-package "SB!C")
+
+(defknown %lea ((or (signed-byte 32) (unsigned-byte 32))
+ (or (signed-byte 32) (unsigned-byte 32))
+ (member 1 2 4 8) (signed-byte 32))
+ (or (signed-byte 32) (unsigned-byte 32))
+ (foldable flushable))
+
+(defoptimizer (%lea derive-type) ((base index scale disp))
+ (when (and (constant-lvar-p scale)
+ (constant-lvar-p disp))
+ (let ((scale (lvar-value scale))
+ (disp (lvar-value disp))
+ (base-type (lvar-type base))
+ (index-type (lvar-type index)))
+ (when (and (numeric-type-p base-type)
+ (numeric-type-p index-type))
+ (let ((base-lo (numeric-type-low base-type))
+ (base-hi (numeric-type-high base-type))
+ (index-lo (numeric-type-low index-type))
+ (index-hi (numeric-type-high index-type)))
+ (make-numeric-type :class 'integer
+ :complexp :real
+ :low (when (and base-lo index-lo)
+ (+ base-lo (* index-lo scale) disp))
+ :high (when (and base-hi index-hi)
+ (+ base-hi (* index-hi scale) disp))))))))
+
+(defun %lea (base index scale disp)
+ (+ base (* index scale) disp))
+
+(in-package "SB!VM")
+
+(define-vop (%lea/unsigned=>unsigned)
+ (:translate %lea)
+ (:policy :fast-safe)
+ (:args (base :scs (unsigned-reg))
+ (index :scs (unsigned-reg)))
+ (:info scale disp)
+ (:arg-types unsigned-num unsigned-num
+ (:constant (member 1 2 4 8))
+ (:constant (signed-byte 32)))
+ (:results (r :scs (unsigned-reg)))
+ (:result-types unsigned-num)
+ (:generator 5
+ (inst lea r (make-ea :dword :base base :index index
+ :scale scale :disp disp))))
+
+(define-vop (%lea/signed=>signed)
+ (:translate %lea)
+ (:policy :fast-safe)
+ (:args (base :scs (signed-reg))
+ (index :scs (signed-reg)))
+ (:info scale disp)
+ (:arg-types signed-num signed-num
+ (:constant (member 1 2 4 8))
+ (:constant (signed-byte 32)))
+ (:results (r :scs (signed-reg)))
+ (:result-types signed-num)
+ (:generator 4
+ (inst lea r (make-ea :dword :base base :index index
+ :scale scale :disp disp))))
+
+(define-vop (%lea/fixnum=>fixnum)
+ (:translate %lea)
+ (:policy :fast-safe)
+ (:args (base :scs (any-reg))
+ (index :scs (any-reg)))
+ (:info scale disp)
+ (:arg-types tagged-num tagged-num
+ (:constant (member 1 2 4 8))
+ (:constant (signed-byte 32)))
+ (:results (r :scs (any-reg)))
+ (:result-types tagged-num)
+ (:generator 3
+ (inst lea r (make-ea :dword :base base :index index
+ :scale scale :disp disp))))
+
+(in-package "SB!C")
+
+;;; This is essentially a straight implementation of the algorithm in
+;;; "Strength Reduction of Multiplications by Integer Constants",
+;;; Youfeng Wu, ACM SIGPLAN Notices, Vol. 30, No.2, February 1995.
+(defun basic-decompose-multiplication (arg num n-bits condensed)
+ (case (aref condensed 0)
+ (0
+ (let ((tmp (min 3 (aref condensed 1))))
+ (decf (aref condensed 1) tmp)
+ `(truly-the (unsigned-byte 32)
+ (%lea ,arg
+ ,(decompose-multiplication
+ arg (ash (1- num) (- tmp)) (1- n-bits) (subseq condensed 1))
+ ,(ash 1 tmp) 0))))
+ ((1 2 3)
+ (let ((r0 (aref condensed 0)))
+ (incf (aref condensed 1) r0)
+ `(truly-the (unsigned-byte 32)
+ (%lea ,(decompose-multiplication
+ arg (- num (ash 1 r0)) (1- n-bits) (subseq condensed 1))
+ ,arg
+ ,(ash 1 r0) 0))))
+ (t (let ((r0 (aref condensed 0)))
+ (setf (aref condensed 0) 0)
+ `(truly-the (unsigned-byte 32)
+ (ash ,(decompose-multiplication
+ arg (ash num (- r0)) n-bits condensed)
+ ,r0))))))
+
+(defun decompose-multiplication (arg num n-bits condensed)
+ (cond
+ ((= n-bits 0) 0)
+ ((= num 1) arg)
+ ((= n-bits 1)
+ `(truly-the (unsigned-byte 32) (ash ,arg ,(1- (integer-length num)))))
+ ((let ((max 0) (end 0))
+ (loop for i from 2 to (length condensed)
+ for j = (reduce #'+ (subseq condensed 0 i))
+ when (and (> (- (* 2 i) 3 j) max)
+ (< (+ (ash 1 (1+ j))
+ (ash (ldb (byte (- 32 (1+ j)) (1+ j)) num)
+ (1+ j)))
+ (ash 1 32)))
+ do (setq max (- (* 2 i) 3 j)
+ end i))
+ (when (> max 0)
+ (let ((j (reduce #'+ (subseq condensed 0 end))))
+ (let ((n2 (+ (ash 1 (1+ j))
+ (ash (ldb (byte (- 32 (1+ j)) (1+ j)) num) (1+ j))))
+ (n1 (1+ (ldb (byte (1+ j) 0) (lognot num)))))
+ `(truly-the (unsigned-byte 32)
+ (- ,(optimize-multiply arg n2) ,(optimize-multiply arg n1))))))))
+ ((dolist (i '(9 5 3))
+ (when (integerp (/ num i))
+ (when (< (logcount (/ num i)) (logcount num))
+ (let ((x (gensym)))
+ (return `(let ((,x ,(optimize-multiply arg (/ num i))))
+ (truly-the (unsigned-byte 32)
+ (%lea ,x ,x (1- ,i) 0)))))))))
+ (t (basic-decompose-multiplication arg num n-bits condensed))))
+
+(defun optimize-multiply (arg x)
+ (let* ((n-bits (logcount x))
+ (condensed (make-array n-bits)))
+ (let ((count 0) (bit 0))
+ (dotimes (i 32)
+ (cond ((logbitp i x)
+ (setf (aref condensed bit) count)
+ (setf count 1)
+ (incf bit))
+ (t (incf count)))))
+ (decompose-multiplication arg x n-bits condensed)))
+
+(deftransform * ((x y)
+ ((unsigned-byte 32) (constant-arg (unsigned-byte 32)))
+ (unsigned-byte 32))
+ "recode as leas, shifts and adds"
+ (let ((y (lvar-value y)))
+ (cond
+ ((= y (ash 1 (integer-length y)))
+ ;; there's a generic transform for y = 2^k
+ (give-up-ir1-transform))
+ ((member y '(3 5 9))
+ ;; we can do these multiplications directly using LEA
+ `(%lea x x ,(1- y) 0))
+ ((member :pentium4 *backend-subfeatures*)
+ ;; the pentium4's multiply unit is reportedly very good
+ (give-up-ir1-transform))
+ ;; FIXME: should make this more fine-grained. If nothing else,
+ ;; there should probably be a cutoff of about 9 instructions on
+ ;; pentium-class machines.
+ (t (optimize-multiply 'x y)))))
+
+;;; FIXME: we should also be able to write an optimizer or two to
+;;; convert (+ (* x 2) 17), (- (* x 9) 5) to a %LEA.
projects / sbcl.git / blobdiff