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Re: [PATCH] Re: Bignum performance


From: Emanuel Berg
Subject: Re: [PATCH] Re: Bignum performance
Date: Mon, 04 Sep 2023 06:13:39 +0200
User-agent: Gnus/5.13 (Gnus v5.13)

Simon Leinen wrote:

> Emacs also has `most-negative-fixnum' and
> `most-positive-fixnum' (borrowed from Common Lisp but now
> part of the core).
>
> On my 64-bit system (GNU Emacs 30.0.50 on aarch64-apple-darwin22.5.0):
>
> (= (- (expt 2 61)) most-negative-fixnum) → t
> (= (1- (expt 2 61)) most-positive-fixnum) → t
>
> (Same as on Emanuel's.)

(let ((bits 62))
  (and (= (-  (expt 2 (1- bits))) most-negative-fixnum)
       (= (1- (expt 2 (1- bits))) most-positive-fixnum) )) ; t

Sweet B)

-- 
underground experts united
https://dataswamp.org/~incal




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