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From: David Laight <David.Laight@ACULAB.COM>
To: 'Linus Torvalds' <torvalds@linux-foundation.org>,
	Arnd Bergmann <arnd@arndb.de>
Cc: "Maciej W. Rozycki" <macro@orcam.me.uk>,
	"Paul E. McKenney" <paulmck@kernel.org>,
	John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
	Arnd Bergmann <arnd@kernel.org>,
	"linux-alpha@vger.kernel.org" <linux-alpha@vger.kernel.org>,
	"Richard Henderson" <richard.henderson@linaro.org>,
	Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
	Matt Turner <mattst88@gmail.com>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Marc Zyngier <maz@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Michael Cree <mcree@orcon.net.nz>,
	Frank Scheiner <frank.scheiner@web.de>
Subject: RE: [PATCH 00/14] alpha: cleanups for 6.10
Date: Sat, 1 Jun 2024 13:51:15 +0000	[thread overview]
Message-ID: <7b84fcf6b64a4553a377c98fdcd48837@AcuMS.aculab.com> (raw)
In-Reply-To: <CAHk-=wimJ2hQhKSq7+4O1EHtkg7eFBwY+fygxD+6sjWqgyDMTQ@mail.gmail.com>

...
> The fact is, the original alpha is the worst architecture ever made.
> The lack of byte instructions and the absolutely horrendous memory
> ordering are fatal flaws. And while the memory ordering arguably had
> excuses for it ("they didn't know better"), the lack of byte ops was
> wilful misdesign that the designers were proud of, and made a central
> tenet of their mess.

If it wasn't from DEC (where the pdp-11 and vax were fine) I'd think
it was someone harking back to the old mainframe days where is was
perfectly normal to only have 'word addressing' and, for example,
to put three 6-bit characters into an 18-bit word (hi Univac!).
(Don't even think how 18-bit words got written to mag tape!)

It is almost as is someone assumed that the only use for byte accesses
was within character arrays - and they can jolly well align the arrays.

Mind you, all the byte shifting needed to get the data onto the
right data bus lines is a PITA and will affect the max cpu frequency [1].
So perhaps they decided it was a 'software problem' so some benchmarks
could run faster.

	David

[1] I've been busy re-implementing the Nios-II cpu.

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

  parent reply	other threads:[~2024-06-01 13:51 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-03  8:11 [PATCH 00/14] alpha: cleanups for 6.10 Arnd Bergmann
2024-05-03  8:11 ` [PATCH 01/14] alpha: sort scr_mem{cpy,move}w() out Arnd Bergmann
2024-05-03  8:11 ` [PATCH 02/14] alpha: fix modversions for strcpy() et.al Arnd Bergmann
2024-05-03  8:11 ` [PATCH 03/14] alpha: add clone3() support Arnd Bergmann
2024-05-03  8:11 ` [PATCH 04/14] alpha: don't make functions public without a reason Arnd Bergmann
2024-05-03  8:11 ` [PATCH 05/14] alpha: sys_sio: fix misspelled ifdefs Arnd Bergmann
2024-05-03  8:11 ` [PATCH 06/14] alpha: missing includes Arnd Bergmann
2024-05-03  8:11 ` [PATCH 07/14] alpha: core_lca: take the unused functions out Arnd Bergmann
2024-05-03  8:11 ` [PATCH 08/14] alpha: jensen, t2 - make __EXTERN_INLINE same as for the rest Arnd Bergmann
2024-05-03  8:11 ` [PATCH 09/14] alpha: trim the unused stuff from asm-offsets.c Arnd Bergmann
2024-05-03  8:11 ` [PATCH 10/14] alpha: remove DECpc AXP150 (Jensen) support Arnd Bergmann
2024-05-03 16:07   ` Linus Torvalds
2024-05-03 17:00   ` Al Viro
2024-05-03 20:07     ` Arnd Bergmann
2024-05-03  8:11 ` [PATCH 11/14] alpha: sable: remove early machine support Arnd Bergmann
2024-05-03  8:11 ` [PATCH 12/14] alpha: remove LCA and APECS based machines Arnd Bergmann
2024-05-03  8:11 ` [PATCH 13/14] alpha: cabriolet: remove EV5 CPU support Arnd Bergmann
2024-05-03  8:11 ` [PATCH 14/14] alpha: drop pre-EV56 support Arnd Bergmann
2024-05-04 15:00   ` Richard Henderson
2024-05-06 10:06     ` Arnd Bergmann
2024-06-03  6:02   ` Jiri Slaby
2024-06-04 13:58     ` Greg KH
2024-05-03 16:06 ` [PATCH 00/14] alpha: cleanups for 6.10 Matt Turner
2024-05-03 20:15   ` Arnd Bergmann
2024-05-06  9:16     ` Michael Cree
2024-05-06 10:11       ` Arnd Bergmann
2024-05-03 16:53 ` John Paul Adrian Glaubitz
2024-05-03 17:19   ` Paul E. McKenney
2024-05-27 23:49   ` Maciej W. Rozycki
2024-05-28 14:43     ` Paul E. McKenney
2024-05-29 18:50       ` Maciej W. Rozycki
2024-05-29 22:09         ` Paul E. McKenney
2024-05-30 22:59           ` Maciej W. Rozycki
2024-05-31  3:56           ` Maciej W. Rozycki
2024-05-31 19:33             ` Paul E. McKenney
2024-06-03 16:22               ` Maciej W. Rozycki
2024-06-03 17:08                 ` Paul E. McKenney
2024-07-01 23:50                   ` Maciej W. Rozycki
2024-05-30  1:08         ` Linus Torvalds
2024-05-30 22:57           ` Maciej W. Rozycki
2024-05-31  0:10             ` Linus Torvalds
2024-06-03 11:09               ` Maciej W. Rozycki
2024-06-03 11:36                 ` John Paul Adrian Glaubitz
2024-06-03 16:57                 ` Linus Torvalds
2024-07-01 23:48                   ` Maciej W. Rozycki
2024-05-31 15:48         ` Arnd Bergmann
2024-05-31 16:32           ` Linus Torvalds
2024-05-31 16:54             ` Arnd Bergmann
2024-06-01 13:51             ` David Laight [this message]
2024-07-01 23:48             ` Maciej W. Rozycki
2024-07-02  1:13               ` Linus Torvalds
2024-07-03  0:12                 ` Maciej W. Rozycki
2024-07-03  0:50                   ` Linus Torvalds
2024-07-04 22:21                     ` Maciej W. Rozycki
2024-06-03 11:33           ` Maciej W. Rozycki

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