(:note "inline fixnum arithmetic")
(:generator 4
(move r x)
- (inst sar r 2)
+ (inst sar r n-fixnum-tag-bits)
(inst imul r y)))
(define-vop (fast-*-c/fixnum=>fixnum fast-safe-arith-op)
(inst cdq)
(inst idiv eax y)
(if (location= quo eax)
- (inst shl eax 2)
- (inst lea quo (make-ea :dword :index eax :scale 4)))
+ (inst shl eax n-fixnum-tag-bits)
+ (inst lea quo (make-ea :dword :index eax
+ :scale (ash 1 n-fixnum-tag-bits))))
(move rem edx)))
(define-vop (fast-truncate-c/fixnum=>fixnum fast-safe-arith-op)
(inst mov y-arg (fixnumize y))
(inst idiv eax y-arg)
(if (location= quo eax)
- (inst shl eax 2)
- (inst lea quo (make-ea :dword :index eax :scale 4)))
+ (inst shl eax n-fixnum-tag-bits)
+ (inst lea quo (make-ea :dword :index eax
+ :scale (ash 1 n-fixnum-tag-bits))))
(move rem edx)))
(define-vop (fast-truncate/unsigned=>unsigned fast-safe-arith-op)
\f
;;;; 32-bit logical operations
-(define-vop (merge-bits)
- (:translate merge-bits)
- (:args (shift :scs (signed-reg unsigned-reg) :target ecx)
- (prev :scs (unsigned-reg) :target result)
- (next :scs (unsigned-reg)))
- (:arg-types tagged-num unsigned-num unsigned-num)
- (:temporary (:sc signed-reg :offset ecx-offset :from (:argument 0)) ecx)
- (:results (result :scs (unsigned-reg) :from (:argument 1)))
- (:result-types unsigned-num)
- (:policy :fast-safe)
- (:generator 4
- (move ecx shift)
- (move result prev)
- (inst shrd result next :cl)))
-
;;; Only the lower 5 bits of the shift amount are significant.
(define-vop (shift-towards-someplace)
(:policy :fast-safe)
(:result-types unsigned-num)
(:generator 1
(move digit fixnum)
- (inst sar digit 2)))
+ (inst sar digit n-fixnum-tag-bits)))
(define-vop (bignum-floor)
(:translate sb!bignum:%floor)
(:generator 1
(move res digit)
(when (sc-is res any-reg control-stack)
- (inst shl res 2))))
+ (inst shl res n-fixnum-tag-bits))))
(define-vop (digit-ashr)
(:translate sb!bignum:%ashr)