From: Emanuel Berg <incal@dataswamp.org>
To: emacs-devel@gnu.org
Subject: Re: [PATCH] Re: Bignum performance (was: Shrinking the C core)
Date: Tue, 15 Aug 2023 16:20:03 +0200 [thread overview]
Message-ID: <87350kgzfw.fsf@dataswamp.org> (raw)
In-Reply-To: 54195cac-0e60-f458-9a07-c1574168be4b@gmail.com
Gerd Möllmann wrote:
>> Are we talking 1 word = 2 bytes = 16 bits here, s2c? If so,
>> the range of fixnums are -32 768 to 32 767 inclusive, so
>> those are hardly huge numbers.
>
> It's a 64-bit machine, more specifically an M1. i.e. arm64.
> How you get from there to these 16 bits escapes me.
Here [1] it says a word for ARM is 32 bits.
So to store zero in a fixnum word it will look like this
00000000 00000000 00000000 00000000
If one bit, the MSB, is used as the sign bit, the interval,
inclusive, is
(list (* -1 (expt 2 (1- 32)))
(1- (expt 2 (1- 32))) )
(-2147483648 2147483647)
Okay, now we are talking some pretty big number alltho I have
seen even bigger ...
[1] https://modexp.wordpress.com/2018/10/30/arm64-assembly/
--
underground experts united
https://dataswamp.org/~incal
next prev parent reply other threads:[~2023-08-15 14:20 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-14 6:28 [PATCH] Re: Bignum performance (was: Shrinking the C core) Gerd Möllmann
2023-08-14 6:56 ` Gerd Möllmann
2023-08-14 7:04 ` Ihor Radchenko
2023-08-14 7:35 ` Gerd Möllmann
2023-08-14 8:09 ` Ihor Radchenko
2023-08-14 9:28 ` Gerd Möllmann
2023-08-14 9:42 ` Ihor Radchenko
2023-08-15 14:03 ` Emanuel Berg
2023-08-15 15:01 ` Ihor Radchenko
2023-08-15 22:21 ` Emanuel Berg
2023-08-15 22:33 ` Emanuel Berg
2023-08-16 4:36 ` tomas
2023-08-16 5:23 ` Emanuel Berg
2023-08-14 16:51 ` Emanuel Berg
2023-08-15 4:58 ` Gerd Möllmann
2023-08-15 14:20 ` Emanuel Berg [this message]
2023-08-15 6:26 ` [PATCH] Re: Bignum performance Po Lu
2023-08-15 14:33 ` Emanuel Berg
2023-08-15 17:07 ` tomas
2023-08-15 22:46 ` Emanuel Berg
2023-08-16 1:31 ` Po Lu
2023-08-16 1:37 ` Emanuel Berg
2023-08-16 3:17 ` Po Lu
2023-08-16 4:44 ` tomas
2023-08-16 5:18 ` Gerd Möllmann
2023-08-16 5:35 ` Emanuel Berg
2023-08-18 7:14 ` Simon Leinen
2023-08-19 13:10 ` Emanuel Berg
2023-08-20 5:07 ` Ihor Radchenko
2023-08-20 6:20 ` Emanuel Berg
2023-08-28 5:32 ` Emanuel Berg
2023-09-03 0:48 ` Emanuel Berg
2023-09-03 8:50 ` Ihor Radchenko
2023-09-03 9:05 ` Emanuel Berg
2023-09-03 10:30 ` Elisp native-comp vs. SBCL for inclist-type-hints benchmark (was: [PATCH] Re: Bignum performance) Ihor Radchenko
2023-09-04 1:03 ` Emanuel Berg
2023-09-03 1:57 ` [PATCH] Re: Bignum performance Emanuel Berg
2023-09-04 4:13 ` Emanuel Berg
2023-08-16 5:41 ` Gerd Möllmann
2023-08-16 6:42 ` Po Lu
2023-08-16 8:05 ` Gerd Möllmann
-- strict thread matches above, loose matches on Subject: below --
2023-08-09 9:46 Shrinking the C core Eric S. Raymond
2023-08-09 12:34 ` Po Lu
2023-08-09 15:51 ` Eric S. Raymond
2023-08-09 23:56 ` Po Lu
2023-08-10 1:19 ` Eric S. Raymond
2023-08-10 7:44 ` Eli Zaretskii
2023-08-10 21:54 ` Emanuel Berg
2023-08-11 10:27 ` Bignum performance (was: Shrinking the C core) Ihor Radchenko
2023-08-11 12:10 ` Emanuel Berg
2023-08-11 12:32 ` Ihor Radchenko
2023-08-11 12:38 ` Emanuel Berg
2023-08-11 14:07 ` [PATCH] " Ihor Radchenko
2023-08-11 18:06 ` Emanuel Berg
2023-08-11 19:41 ` Ihor Radchenko
2023-08-11 19:50 ` Emanuel Berg
2023-08-12 8:24 ` Ihor Radchenko
2023-08-12 16:03 ` Emanuel Berg
2023-08-13 9:09 ` Ihor Radchenko
2023-08-13 9:49 ` Emanuel Berg
2023-08-13 10:21 ` Ihor Radchenko
2023-08-14 2:20 ` Emanuel Berg
2023-08-14 7:20 ` Ihor Radchenko
2023-08-11 22:46 ` Emanuel Berg
2023-08-12 8:30 ` Ihor Radchenko
2023-08-12 16:22 ` Emanuel Berg
2023-08-13 9:12 ` Ihor Radchenko
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