-;;;; x86 definition of character operations
+;;;; x86-64 definition of character operations
;;;; This software is part of the SBCL system. See the README file for
;;;; more information.
(in-package "SB!VM")
\f
+;;; Space optimization: As the upper 32 bits of (tagged or untagged)
+;;; characters are always zero many operations can be done on 32-bit
+;;; registers. This often leads to smaller encodings as the REX prefix
+;;; is then only needed if registers R8 - R15 are used.
+
;;;; moves and coercions
;;; Move a tagged char to an untagged representation.
:load-if (not (location= x y))))
(:note "character untagging")
(:generator 1
- (move y x)
- (inst shr y n-widetag-bits)))
+ (cond ((and (sc-is y character-reg) (sc-is x any-reg descriptor-reg))
+ (let ((y-dword (make-dword-tn y)))
+ (unless (location= x y)
+ (inst mov y-dword (make-dword-tn x)))
+ (inst shr y-dword n-widetag-bits)))
+ (t
+ (move y x)
+ (inst shr y n-widetag-bits)))))
#!-sb-unicode
(define-vop (move-to-character)
(:args (x :scs (any-reg control-stack)))
;;; Move an untagged char to a tagged representation.
#!+sb-unicode
(define-vop (move-from-character)
- (:args (x :scs (character-reg)))
+ (:args (x :scs (character-reg) :target y))
(:results (y :scs (any-reg descriptor-reg)))
(:note "character tagging")
(:generator 1
- (inst imul y x (ash 1 n-widetag-bits))
- (inst or y character-widetag)))
+ (let ((y-dword (make-dword-tn y)))
+ (unless (location= x y)
+ (inst mov y-dword (make-dword-tn x)))
+ (inst shl y-dword n-widetag-bits)
+ (inst or y-dword character-widetag))))
#!-sb-unicode
(define-vop (move-from-character)
(:args (x :scs (character-reg character-stack)))
(define-vop (char-code)
(:translate char-code)
(:policy :fast-safe)
- (:args (ch :scs (character-reg character-stack)))
+ (:args #!-sb-unicode (ch :scs (character-reg character-stack))
+ #!+sb-unicode (ch :scs (character-reg character-stack) :target res))
(:arg-types character)
(:results (res :scs (unsigned-reg)))
(:result-types positive-fixnum)
#!-sb-unicode
(inst movzx res ch)
#!+sb-unicode
- (inst mov res ch)))
+ (move res ch)))
#!+sb-unicode
(define-vop (code-char)
(:translate code-char)
(:policy :fast-safe)
- (:args (code :scs (unsigned-reg unsigned-stack)))
+ (:args (code :scs (unsigned-reg unsigned-stack) :target res))
(:arg-types positive-fixnum)
(:results (res :scs (character-reg)))
(:result-types character)
(:generator 1
- (inst mov res code)))
+ (move res code)))
#!-sb-unicode
(define-vop (code-char)
(:translate code-char)
:load-if (not (and (sc-is x character-reg)
(sc-is y character-stack)))))
(:arg-types character character)
- (:conditional)
- (:info target not-p)
+ (:info)
(:policy :fast-safe)
(:note "inline comparison")
- (:variant-vars condition not-condition)
(:generator 3
- (inst cmp x y)
- (inst jmp (if not-p not-condition condition) target)))
+ (inst cmp x y)))
(define-vop (fast-char=/character character-compare)
(:translate char=)
- (:variant :e :ne))
+ (:conditional :e))
(define-vop (fast-char</character character-compare)
(:translate char<)
- (:variant :b :nb))
+ (:conditional :b))
(define-vop (fast-char>/character character-compare)
(:translate char>)
- (:variant :a :na))
+ (:conditional :a))
(define-vop (character-compare/c)
(:args (x :scs (character-reg character-stack)))
(:arg-types character (:constant character))
- (:conditional)
- (:info target not-p y)
+ (:info y)
(:policy :fast-safe)
(:note "inline constant comparison")
- (:variant-vars condition not-condition)
(:generator 2
- (inst cmp x (sb!xc:char-code y))
- (inst jmp (if not-p not-condition condition) target)))
+ (inst cmp x (sb!xc:char-code y))))
(define-vop (fast-char=/character/c character-compare/c)
(:translate char=)
- (:variant :e :ne))
+ (:conditional :e))
(define-vop (fast-char</character/c character-compare/c)
(:translate char<)
- (:variant :b :nb))
+ (:conditional :b))
(define-vop (fast-char>/character/c character-compare/c)
(:translate char>)
- (:variant :a :na))
+ (:conditional :a))