Sujet : Re: Byte Addressability And Beyond
De : mitchalsup (at) *nospam* aol.com (MitchAlsup1)
Groupes : comp.archDate : 07. May 2024, 02:53:29
Autres entêtes
Organisation : Rocksolid Light
Message-ID : <0c13eeb8c7766f2900ee2f55f788a366@www.novabbs.org>
References : 1 2 3 4 5 6 7 8 9 10 11 12 13
User-Agent : Rocksolid Light
BGB wrote:
On 5/6/2024 2:11 PM, MitchAlsup1 wrote:
Lawrence D'Oliveiro wrote:
On Sun, 5 May 2024 20:50:51 -0500, BGB wrote:
Say, RISC-V:
Says yes to DIV and MOD;
Says yes to 4-register floating-point multiple-accumulate; Say no to
register-indexed Load/Store.
Me: This is not a good balance...
Multiply-accumulate is at least as much about reducing rounding error as about speed.
It is also an IEEE 754-2008+ requirement.
And... I have a version that just sort of works well enough to make RV64G work, but is sort of a fail on the other fronts:
Using it is slower than separate ops;
It produces a double-rounded result.
Also, well, the FMUL isn't super accurate either.
So, it fails IEEE 754-accuracy requirements.
FMUL is implemented in a way where it only generates the high-half of the multiply, which makes the FPU cheaper, but:
Does not give strict 0.5ULP rounding.
Also failing EEE 754-accuracy requirements.
Some combination of factors leads to the inability of Newton-Raphson to fully converge, possibly either due to omitting the low-order multiplier results, or the carry-propagation limitation for rounding (if the rounding would result in more than 8 bits of carry, it is skipped).
Newton-Raphson is dependent on getting the bits right so that its
interpolation (between iterations) converges properly.
Not likely to do proper FMA, as this would make a Binary64 FPU too expensive (and, doing Binary64 poorly is still preferable for most uses to not doing it at all).
And yet, every other non FPGA implementation achieves those requirements.
It really seams that your medium is influencing your architecture,
rather than the other way around.
Granted, not entirely sure how the 8087 managed to do all the stuff that it did. Since, it seems like an 80s ASIC would be more cramped than a modern Artix-7.
Mostly it was simply slow.
....
Date | Sujet | # | | Auteur |
1 May 24 | Byte Addressability And Beyond | 590 | | Lawrence D'Oliveiro |
1 May 24 | Re: Byte Addressability And Beyond | 431 | | John Levine |
1 May 24 | Re: Byte Addressability And Beyond | 409 | | Lawrence D'Oliveiro |
1 May 24 | Re: Byte Addressability And Beyond | 3 | | John Levine |
1 May 24 | Re: Byte Addressability And Beyond | 1 | | John Levine |
1 May 24 | Re: Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
1 May 24 | Re: Byte Addressability And Beyond | 1 | | Michael S |
1 May 24 | Re: Byte Addressability And Beyond | 404 | | John Levine |
2 May 24 | Re: Byte Addressability And Beyond | 382 | | Lawrence D'Oliveiro |
2 May 24 | Re: Byte Addressability And Beyond | 4 | | John Levine |
2 May 24 | Re: Byte Addressability And Beyond | 3 | | Lawrence D'Oliveiro |
2 May 24 | Re: Byte Addressability And Beyond | 2 | | John Levine |
5 May 24 | Re: Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
2 May 24 | Re: Byte Addressability And Beyond | 367 | | John Savard |
2 May 24 | Re: Byte Addressability And Beyond | 2 | | MitchAlsup1 |
11 May 24 | Re: Byte Addressability And Beyond | 1 | | John Savard |
4 May 24 | Re: Byte Addressability And Beyond | 364 | | Lawrence D'Oliveiro |
8 May 24 | Re: Byte Addressability And Beyond | 363 | | John Savard |
8 May 24 | Re: Byte Addressability And Beyond | 2 | | Lawrence D'Oliveiro |
10 May 24 | Re: Byte Addressability And Beyond | 1 | | David Brown |
8 May 24 | Re: Byte Addressability And Beyond | 360 | | MitchAlsup1 |
8 May 24 | Re: Byte Addressability And Beyond | 359 | | John Levine |
8 May 24 | Re: Byte Addressability And Beyond | 357 | | Lawrence D'Oliveiro |
9 May 24 | Re: Byte Addressability And Beyond | 356 | | John Levine |
10 May 24 | Re: Byte Addressability And Beyond | 354 | | David Brown |
10 May 24 | Re: Byte Addressability And Beyond | 353 | | Anton Ertl |
11 May 24 | Re: Byte Addressability And Beyond | 352 | | David Brown |
11 May 24 | Re: Byte Addressability And Beyond | 351 | | Anton Ertl |
11 May 24 | Re: Byte Addressability And Beyond | 158 | | David Brown |
11 May 24 | Re: Byte Addressability And Beyond | 1 | | Anton Ertl |
27 May 24 | Re: Byte Addressability And Beyond | 156 | | Lawrence D'Oliveiro |
27 May 24 | Re: Byte Addressability And Beyond | 155 | | John Levine |
27 May 24 | Re: Byte Addressability And Beyond | 154 | | Lawrence D'Oliveiro |
27 May 24 | Re: Byte Addressability And Beyond | 153 | | John Levine |
27 May 24 | Re: Byte Addressability And Beyond | 149 | | John Levine |
27 May 24 | Re: Byte Addressability And Beyond | 1 | | MitchAlsup1 |
28 May 24 | Re: Byte Addressability And Beyond | 147 | | Lawrence D'Oliveiro |
28 May 24 | Re: encoding conversion, Byte Addressability And Beyond | 1 | | John Levine |
28 May 24 | Re: Byte Addressability And Beyond | 145 | | Thomas Koenig |
29 May 24 | Re: Byte Addressability And Beyond | 137 | | Lawrence D'Oliveiro |
29 May 24 | Re: Byte Addressability And Beyond | 136 | | Anton Ertl |
29 May 24 | Re: Byte Addressability And Beyond | 12 | | Stefan Monnier |
29 May 24 | Re: Byte Addressability And Beyond | 10 | | Stefan Monnier |
29 May 24 | Re: Byte Addressability And Beyond | 3 | | John Levine |
30 May 24 | Re: Byte Addressability And Beyond | 2 | | George Neuner |
4 Jun 24 | Re: Byte Addressability And Beyond | 1 | | George Neuner |
30 May 24 | Re: Byte Addressability And Beyond | 6 | | Anton Ertl |
4 Jun 24 | Re: Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
4 Jun 24 | Re: Byte Addressability And Beyond | 4 | | Stefan Monnier |
7 Jun 24 | Re: Byte Addressability And Beyond | 1 | | Terje Mathisen |
7 Jun 24 | Re: Character non-equivalence, was Byte Addressability And Beyond | 2 | | John Levine |
9 Jun 24 | Re: Character non-equivalence, was Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
30 May 24 | Re: Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
30 May 24 | Re: Byte Addressability And Beyond | 117 | | Lawrence D'Oliveiro |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 66 | | John Levine |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Stephen Fuld |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 22 | | Anton Ertl |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 21 | | Thomas Koenig |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 8 | | Michael S |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Thomas Koenig |
30 May 24 | Re: IBM architectural goals, Byte Addressability And Beyond | 5 | | John Levine |
30 May 24 | Re: IBM architectural goals, Byte Addressability And Beyond | 2 | | Michael S |
30 May 24 | Re: IBM architectural goals, Byte Addressability And Beyond | 1 | | John Levine |
30 May 24 | Re: IBM architectural goals, Byte Addressability And Beyond | 2 | | Thomas Koenig |
30 May 24 | Re: IBM architectural goals, Byte Addressability And Beyond | 1 | | John Levine |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Anton Ertl |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 3 | | Anton Ertl |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | John Levine |
30 May 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Thomas Koenig |
31 May 24 | Re: architectural goals, Byte Addressability And Beyond | 5 | | Terje Mathisen |
1 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 4 | | Thomas Koenig |
1 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 3 | | Anton Ertl |
2 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 2 | | John Levine |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Stefan Monnier |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 4 | | Lawrence D'Oliveiro |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | MitchAlsup1 |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Lynn Wheeler |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Stefan Monnier |
31 May 24 | Re: architectural goals, Byte Addressability And Beyond | 42 | | John Savard |
31 May 24 | Re: architectural goals, Byte Addressability And Beyond | 41 | | John Levine |
1 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 31 | | John Savard |
1 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 20 | | Thomas Koenig |
2 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 6 | | John Savard |
2 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 5 | | Thomas Koenig |
2 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 3 | | John Levine |
3 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 2 | | OrangeFish |
3 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | John Levine |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 13 | | Lawrence D'Oliveiro |
5 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 12 | | Lawrence D'Oliveiro |
5 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
6 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 10 | | George Neuner |
6 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 6 | | John Levine |
7 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 4 | | Lawrence D'Oliveiro |
7 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 3 | | Stephen Fuld |
7 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 2 | | Lawrence D'Oliveiro |
7 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Stephen Fuld |
7 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Terje Mathisen |
6 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Lynn Wheeler |
6 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | OrangeFish |
7 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
2 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 10 | | John Dallman |
2 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | Michael S |
2 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 1 | | John Dallman |
4 Jun 24 | Re: architectural goals, Byte Addressability And Beyond | 7 | | Lawrence D'Oliveiro |
30 May 24 | Re: Byte Addressability And Beyond | 49 | | Stephen Fuld |
30 May 24 | Re: Byte Addressability And Beyond | 1 | | Anton Ertl |
30 May 24 | Re: Byte Addressability And Beyond | 2 | | Lawrence D'Oliveiro |
30 May 24 | Re: Byte Addressability And Beyond | 4 | | Terje Mathisen |
30 May 24 | Re: Byte Addressability And Beyond | 7 | | Terje Mathisen |
28 May 24 | Re: Byte Addressability And Beyond | 3 | | Lawrence D'Oliveiro |
12 May 24 | Re: python text, Byte Addressability And Beyond | 14 | | John Levine |
12 May 24 | Re: Byte Addressability And Beyond | 178 | | Thomas Koenig |
27 May 24 | Re: Byte Addressability And Beyond | 1 | | Lawrence D'Oliveiro |
8 May 24 | Re: Byte Addressability And Beyond | 1 | | Michael S |
2 May 24 | Re: Byte Addressability And Beyond | 10 | | MitchAlsup1 |
2 May 24 | Re: Byte Addressability And Beyond | 3 | | Michael S |
2 May 24 | Re: Byte Addressability And Beyond | 18 | | Anton Ertl |
1 May 24 | Byte Order (was: Byte Addressability And Beyond) | 4 | | Anton Ertl |
1 May 24 | Re: Byte Addressability And Beyond | 17 | | Stefan Monnier |
1 May 24 | Re: Byte Addressability And Beyond | 40 | | MitchAlsup1 |
1 May 24 | Re: Byte Addressability And Beyond | 15 | | Thomas Koenig |
1 May 24 | Re: Byte Addressability And Beyond | 3 | | Michael S |
2 May 24 | Re: Byte Addressability And Beyond | 4 | | Lawrence D'Oliveiro |
3 May 24 | Re: Byte Addressability And Beyond | 75 | | Anton Ertl |
5 May 24 | Re: Byte Addressability And Beyond | 20 | | John Savard |
5 May 24 | Re: Byte Addressability And Beyond | 1 | | John Savard |