Raymond Toy pushed to branch master at cmucl / cmucl

Commits:

2 changed files:

Changes:

  • src/bootfiles/21e/boot-2023-08.lisp
    ... ... @@ -2,3 +2,46 @@
    2 2 
     ;; *SOFTWARE-VERSION* from the LISP package to the SYSTEM package.
    3 3 
     (ext:without-package-locks
    4 4 
         (unintern 'lisp::*software-version* "LISP"))
    5 
    +
    6 
    +#+(or random-mt19937 random-xoroshiro)
    7 
    +(in-package "C")
    8 
    +#+(or random-mt19937 random-xoroshiro)
    9 
    +(deftransform random ((num &optional state)
    10 
    +		      ((integer 1 #.(expt 2 32)) &optional *))
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    +  _N"use inline (unsigned-byte 32) operations"
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    +  (let* ((num-type (continuation-type num))
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    +	 (num-high (cond ((numeric-type-p num-type)
    14 
    +			  (numeric-type-high num-type))
    15 
    +			 ((union-type-p num-type)
    16 
    +			  ;; Find the maximum of the union type.  We
    17 
    +			  ;; know this works because if we're in this
    18 
    +			  ;; routine, NUM must be a subtype of
    19 
    +			  ;; (INTEGER 1 2^32), so each member of the
    20 
    +			  ;; union must be a subtype too.
    21 
    +			  (reduce #'max (union-type-types num-type)
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    +				  :key #'numeric-type-high))
    23 
    +			 (t
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    +			  (give-up)))))
    25 
    +    ;; Rather than doing (rem (random-chunk) num-high), we do,
    26 
    +    ;; essentially, (rem (* num-high (random-chunk)) #x100000000).  I
    27 
    +    ;; (rtoy) believe this approach doesn't have the bias issue with
    28 
    +    ;; doing rem.  This method works by treating (random-chunk) as if
    29 
    +    ;; it were a 32-bit fraction between 0 and 1, exclusive.  Multiply
    30 
    +    ;; this by num-high to get a random number between 0 and num-high,
    31 
    +    ;; This should have no bias.
    32 
    +    (cond ((constant-continuation-p num)
    33 
    +	   (if (= num-high (expt 2 32))
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    +	       '(random-chunk (or state *random-state*))
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    +	       '(values (bignum::%multiply
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    +			 (random-chunk (or state *random-state*))
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    +			 num))))
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    +	  ((< num-high (expt 2 32))
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    +	   '(values (bignum::%multiply (random-chunk (or state *random-state*))
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    +		     num)))
    41 
    +	  ((= num-high (expt 2 32))
    42 
    +	   '(if (= num (expt 2 32))
    43 
    +		(random-chunk (or state *random-state*))
    44 
    +		(values (bignum::%multiply (random-chunk (or state *random-state*))
    45 
    +					   num))))
    46 
    +	  (t
    47 
    +	   (error (intl:gettext "Shouldn't happen"))))))

  • src/code/rand-xoroshiro.lisp
    ... ... @@ -490,11 +490,8 @@
    490 490 
       (declare (inline %random-single-float %random-double-float))
    491 491 
       (cond
    492 492 
         ((typep arg '(integer 1 #x100000000))
    493 
    -     ;; Do the same thing as the deftransform would do.
    494 
    -     (if (= arg (expt 2 32))
    495 
    -	 (random-chunk state)
    496 
    -	 (values (bignum::%multiply (random-chunk state)
    497 
    -				    arg))))
    493 
    +     ;; Let the compiler deftransform take care of this case.
    494 
    +     (random arg state))
    498 495 
         ((and (typep arg 'single-float) (> arg 0.0F0))
    499 496 
          (%random-single-float arg state))
    500 497 
         ((and (typep arg 'double-float) (> arg 0.0D0))

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