Re: Byte ordering

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Sujet : Re: Byte ordering
De : jgd (at) *nospam* cix.co.uk (John Dallman)
Groupes : comp.arch
Date : 05. Jan 2025, 15:48:26
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <memo.20250105144856.20984i@jgd.cix.co.uk>
References : 1
In article <2025Jan3.093849@mips.complang.tuwien.ac.at>,
anton@mips.complang.tuwien.ac.at (Anton Ertl) wrote:

The 8086 has branches with 8-bit offsets and branches and calls
with 16-bit offsets. The 386 in 32-bit mode has branches with
8-bit offsets and branches and calls with 32-bit offsets; if
16-bit offsets for branches would be useful enough for performance,
they could instead have designed the longer branch length to be
16 bits, and maybe a prefix for 32-bit branch offsets.  That would
be faster than what you outline, as soon as one call happens. 
But apparently 16-bit branches are not that beneficial, or they
would have gone that way on the 386.

Don't assume that Intel of the early 1980s would have done enough
simulation to explore those possibilities thoroughly. Given the mistakes
they made in the 1970s with iAPX 432 and in the 1990s with Itanium, both
through lack of simulation with varying workloads, they may well have
been working by rules of thumb and engineering "intuition."

John

Date Sujet#  Auteur
1 Oct 24 * Re: Whether something is RISC or not (Re: PDP-8 theology, not Concertina II Progress)387MitchAlsup1
1 Oct 24 `* Re: Whether something is RISC or not (Re: PDP-8 theology, not Concertina II Progress)386Thomas Koenig
1 Oct 24  +* Re: Whether something is RISC or not (Re: PDP-8 theology, not Concertina II Progress)379MitchAlsup1
2 Oct 24  i+* Re: Whether something is RISC or not (Re: PDP-8 theology, not Concertina II Progress)377Brett
3 Oct 24  ii`* Re: Whether something is RISC or not (Re: PDP-8 theology, not Concertina II Progress)376Lawrence D'Oliveiro
3 Oct 24  ii +- Re: Whether something is RISC or not (Re: PDP-8 theology, not Concertina II Progress)1Brett
3 Oct 24  ii +- Re: Whether something is RISC or not (Re: PDP-8 theology, not Concertina II Progress)1Anton Ertl
3 Oct 24  ii `* Re: Whether something is RISC or not (Re: PDP-8 theology, not Concertina II Progress)373David Brown
3 Oct 24  ii  `* Byte ordering (was: Whether something is RISC or not)372Anton Ertl
3 Oct 24  ii   +- Re: Byte ordering (was: Whether something is RISC or not)1David Brown
3 Oct 24  ii   +* Re: Byte ordering (was: Whether something is RISC or not)369Lawrence D'Oliveiro
4 Oct 24  ii   i+- Re: Byte ordering1Lynn Wheeler
4 Oct 24  ii   i+* Re: Byte ordering (was: Whether something is RISC or not)365David Brown
4 Oct 24  ii   ii`* Re: Byte ordering (was: Whether something is RISC or not)364Anton Ertl
4 Oct 24  ii   ii +* Re: Byte ordering5BGB
5 Oct 24  ii   ii i`* Re: Byte ordering4MitchAlsup1
5 Oct 24  ii   ii i +* Re: Byte ordering2BGB
5 Oct 24  ii   ii i i`- Re: Byte ordering1Lawrence D'Oliveiro
5 Oct 24  ii   ii i `- Re: Byte ordering1Lawrence D'Oliveiro
5 Oct 24  ii   ii +* Re: Byte ordering (was: Whether something is RISC or not)13Lawrence D'Oliveiro
5 Oct 24  ii   ii i`* Re: Byte ordering (was: Whether something is RISC or not)12Brett
5 Oct 24  ii   ii i `* Re: Byte ordering (was: Whether something is RISC or not)11Anton Ertl
5 Oct 24  ii   ii i  `* Re: Byte ordering (was: Whether something is RISC or not)10Michael S
6 Oct 24  ii   ii i   +- Re: Byte ordering1Terje Mathisen
6 Oct 24  ii   ii i   `* Re: Byte ordering (was: Whether something is RISC or not)8Brett
7 Oct 24  ii   ii i    `* Re: Byte ordering (was: Whether something is RISC or not)7Lawrence D'Oliveiro
7 Oct 24  ii   ii i     `* Re: Byte ordering (was: Whether something is RISC or not)6Brett
7 Oct 24  ii   ii i      `* Re: Byte ordering (was: Whether something is RISC or not)5Michael S
7 Oct 24  ii   ii i       +* Re: Byte ordering2Stefan Monnier
7 Oct 24  ii   ii i       i`- Re: Byte ordering1Michael S
7 Oct 24  ii   ii i       `* Re: Byte ordering (was: Whether something is RISC or not)2Lawrence D'Oliveiro
8 Oct 24  ii   ii i        `- Re: Byte ordering1Terje Mathisen
6 Oct 24  ii   ii `* Re: Byte ordering345David Brown
6 Oct 24  ii   ii  `* Re: Byte ordering344Anton Ertl
6 Oct 24  ii   ii   +* Re: Byte ordering189John Dallman
7 Oct 24  ii   ii   i+* Re: Byte ordering20Lawrence D'Oliveiro
8 Oct 24  ii   ii   ii`* Re: Byte ordering19John Dallman
9 Oct 24  ii   ii   ii +- VMS/NT memory management (was: Byte ordering)1Stefan Monnier
15 Oct 24  ii   ii   ii +* Re: Byte ordering2Lawrence D'Oliveiro
15 Oct 24  ii   ii   ii i`- Re: Byte ordering1MitchAlsup1
15 Oct 24  ii   ii   ii `* Re: Byte ordering15Lawrence D'Oliveiro
15 Oct 24  ii   ii   ii  +* Re: Byte ordering3Michael S
15 Oct 24  ii   ii   ii  i+- Re: Byte ordering1John Dallman
18 Oct 24  ii   ii   ii  i`- Re: Byte ordering1Lawrence D'Oliveiro
15 Oct 24  ii   ii   ii  +* Re: Byte ordering9John Dallman
16 Oct 24  ii   ii   ii  i+* Re: Byte ordering7George Neuner
16 Oct 24  ii   ii   ii  ii`* Re: Byte ordering6Terje Mathisen
16 Oct 24  ii   ii   ii  ii `* Re: Byte ordering5David Brown
17 Oct 24  ii   ii   ii  ii  +* Re: Byte ordering2George Neuner
17 Oct 24  ii   ii   ii  ii  i`- Re: Byte ordering1David Brown
17 Oct 24  ii   ii   ii  ii  `* Re: clouds, not Byte ordering2John Levine
17 Oct 24  ii   ii   ii  ii   `- Re: clouds, not Byte ordering1David Brown
18 Oct 24  ii   ii   ii  i`- Re: Byte ordering1Lawrence D'Oliveiro
16 Oct 24  ii   ii   ii  `* Re: Byte ordering2Paul A. Clayton
18 Oct 24  ii   ii   ii   `- Re: Microkernels & Capabilities (was Re: Byte ordering)1Lawrence D'Oliveiro
7 Oct 24  ii   ii   i`* 80286 protected mode168Anton Ertl
7 Oct 24  ii   ii   i +* Re: 80286 protected mode5Lars Poulsen
7 Oct 24  ii   ii   i i`* Re: 80286 protected mode4Terje Mathisen
7 Oct 24  ii   ii   i i +- Re: 80286 protected mode1Michael S
7 Oct 24  ii   ii   i i `* Re: 80286 protected mode2Lawrence D'Oliveiro
8 Oct 24  ii   ii   i i  `- Re: 80286 protected mode1Terje Mathisen
7 Oct 24  ii   ii   i +* Re: 80286 protected mode3Brett
7 Oct 24  ii   ii   i i`* Re: 80286 protected mode2Michael S
7 Oct 24  ii   ii   i i `- Re: 80286 protected mode1Brett
7 Oct 24  ii   ii   i +- Re: 80286 protected mode1Lawrence D'Oliveiro
8 Oct 24  ii   ii   i +* Re: 80286 protected mode152MitchAlsup1
8 Oct 24  ii   ii   i i+* Re: 80286 protected mode4Lawrence D'Oliveiro
8 Oct 24  ii   ii   i ii`* Re: 80286 protected mode3MitchAlsup1
9 Oct 24  ii   ii   i ii +- Re: 80286 protected mode1David Brown
15 Oct 24  ii   ii   i ii `- Re: 80286 protected mode1Lawrence D'Oliveiro
8 Oct 24  ii   ii   i i`* Re: 80286 protected mode147Anton Ertl
8 Oct 24  ii   ii   i i +- Re: 80286 protected mode1Robert Finch
9 Oct 24  ii   ii   i i `* Re: 80286 protected mode145David Brown
9 Oct 24  ii   ii   i i  +* Re: 80286 protected mode79MitchAlsup1
9 Oct 24  ii   ii   i i  i`* Re: 80286 protected mode78David Brown
9 Oct 24  ii   ii   i i  i `* Re: 80286 protected mode77Stephen Fuld
10 Oct 24  ii   ii   i i  i  +* Re: 80286 protected mode2MitchAlsup1
10 Oct 24  ii   ii   i i  i  i`- Re: 80286 protected mode1David Brown
10 Oct 24  ii   ii   i i  i  +- Re: 80286 protected mode1David Brown
11 Oct 24  ii   ii   i i  i  `* Re: 80286 protected mode73Tim Rentsch
15 Oct 24  ii   ii   i i  i   `* Re: 80286 protected mode72Stefan Monnier
15 Oct 24  ii   ii   i i  i    +* Re: 80286 protected mode30MitchAlsup1
16 Oct 24  ii   ii   i i  i    i+* Re: 80286 protected mode25MitchAlsup1
16 Oct 24  ii   ii   i i  i    ii+* Re: C and turtles, 80286 protected mode13John Levine
16 Oct 24  ii   ii   i i  i    iii+* Re: C and turtles, 80286 protected mode7MitchAlsup1
16 Oct 24  ii   ii   i i  i    iiii`* Re: C and turtles, 80286 protected mode6John Levine
17 Oct 24  ii   ii   i i  i    iiii `* Re: C and turtles, 80286 protected mode5Thomas Koenig
20 Oct 24  ii   ii   i i  i    iiii  `* Re: C and turtles, 80286 protected mode4Lawrence D'Oliveiro
20 Oct 24  ii   ii   i i  i    iiii   `* Re: C and turtles, 80286 protected mode3George Neuner
22 Oct 24  ii   ii   i i  i    iiii    `* Re: C and turtles, 80286 protected mode2Tim Rentsch
22 Oct 24  ii   ii   i i  i    iiii     `- Re: C and turtles, 80286 protected mode1George Neuner
16 Oct 24  ii   ii   i i  i    iii+- Re: C and turtles, 80286 protected mode1David Brown
16 Oct 24  ii   ii   i i  i    iii`* Re: C and turtles, 80286 protected mode4Paul A. Clayton
17 Oct 24  ii   ii   i i  i    iii +- Re: C and turtles, 80286 protected mode1David Brown
20 Oct 24  ii   ii   i i  i    iii `* Re: C and turtles, 80286 protected mode2Lawrence D'Oliveiro
20 Oct 24  ii   ii   i i  i    iii  `- Re: C and turtles, 80286 protected mode1Paul A. Clayton
16 Oct 24  ii   ii   i i  i    ii+* Re: 80286 protected mode7Thomas Koenig
16 Oct 24  ii   ii   i i  i    iii+* Re: 80286 protected mode2MitchAlsup1
17 Oct 24  ii   ii   i i  i    iiii`- Re: 80286 protected mode1Tim Rentsch
17 Oct 24  ii   ii   i i  i    iii`* Re: 80286 protected mode4Tim Rentsch
17 Oct 24  ii   ii   i i  i    iii `* Re: fine points of dynamic memory allocation, not 80286 protected mode3John Levine
17 Oct 24  ii   ii   i i  i    ii+* Re: 80286 protected mode3George Neuner
17 Oct 24  ii   ii   i i  i    ii`- Re: 80286 protected mode1Tim Rentsch
16 Oct 24  ii   ii   i i  i    i+* Re: 80286 protected mode3David Brown
17 Oct 24  ii   ii   i i  i    i`- Re: 80286 protected mode1Tim Rentsch
16 Oct 24  ii   ii   i i  i    `* Re: 80286 protected mode41David Brown
9 Oct 24  ii   ii   i i  +* Re: 80286 protected mode51Thomas Koenig
13 Oct 24  ii   ii   i i  `* Re: 80286 protected mode14Anton Ertl
8 Oct 24  ii   ii   i `* Re: 80286 protected mode6John Levine
3 Jan 25  ii   ii   `* Re: Byte ordering154Waldek Hebisch
6 Oct 24  ii   i`* Re: Byte ordering (was: Whether something is RISC or not)2Michael S
3 Oct 24  ii   `- Re: Byte ordering (was: Whether something is RISC or not)1John Dallman
2 Oct 24  i`- Re: Whether something is RISC or not (Re: PDP-8 theology, not Concertina II Progress)1Thomas Koenig
2 Oct 24  +* Re: Whether something is RISC or not (Re: PDP-8 theology, not Concertina II Progress)5David Schultz
3 Oct 24  `- Re: Whether something is RISC or not (Re: PDP-8 theology, not Concertina II Progress)1Lawrence D'Oliveiro

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