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MitchAlsup1 wrote:On Fri, 19 Jul 2024 14:16:01 +0000, Terje Mathisen wrote:Back when I first looked at Invsqrt(), I did so because an
Computation Fluid Chemistry researcher from Sweden asked for help
speeding up his reciprocal calculations
(sqrt(1/(dx^2+dy^2+dz^2))), I found that by combining the 1/x and
the sqrt and doing three of them pipelind together (all the water
molecules having three atoms), his weeklong simulation runs ran in
half the time, on both PentiumPro and Alpha hardware.
I, personally, have found many Newton-Raphson iterators that
converge faster using 1/SQRT(x) than using the SQRT(x) equivalent.
Yeah, that was eye-opening to me as well, to the level where I
consider the invsqrt() NR iteration as a mainstay, it can be useful
for both sqrt and 1/x as well. :-)
Terje
Date | Sujet | # | Auteur | |
13 Jul 24 | Continuations | 138 | Lawrence D'Oliveiro | |
13 Jul 24 | Re: Continuations | 4 | BGB | |
14 Jul 24 | Re: Continuations | 2 | aph | |
15 Jul 24 | Re: Continuations | 1 | Lawrence D'Oliveiro | |
14 Jul 24 | Re: Continuations | 1 | Anton Ertl | |
13 Jul 24 | Re: Continuations | 23 | John Dallman | |
14 Jul 24 | Re: Continuations | 21 | Lawrence D'Oliveiro | |
14 Jul 24 | Re: Continuations | 20 | George Neuner | |
14 Jul 24 | Re: Continuations | 19 | John Levine | |
14 Jul 24 | Re: Continuations | 18 | Niklas Holsti | |
15 Jul 24 | Re: Continuations | 16 | John Levine | |
15 Jul 24 | Re: Continuations | 1 | Terje Mathisen | |
15 Jul 24 | Re: Continuations | 1 | John Levine | |
15 Jul 24 | Re: Continuations | 9 | Niklas Holsti | |
16 Jul 24 | Re: Continuations | 8 | Lawrence D'Oliveiro | |
16 Jul 24 | Re: Continuations | 7 | John Levine | |
16 Jul 24 | Re: Continuations | 1 | Chris M. Thomasson | |
16 Jul 24 | Re: Continuations | 5 | Lawrence D'Oliveiro | |
16 Jul 24 | Re: Continuations | 4 | John Levine | |
16 Jul 24 | Re: Continuations | 3 | Lawrence D'Oliveiro | |
16 Jul 24 | Re: Continuations | 2 | MitchAlsup1 | |
17 Jul 24 | Re: Continuations | 1 | Lawrence D'Oliveiro | |
16 Jul 24 | Re: Continuations | 3 | Lawrence D'Oliveiro | |
16 Jul 24 | Re: Continuations | 2 | MitchAlsup1 | |
16 Jul 24 | Re: Continuations | 1 | Lawrence D'Oliveiro | |
16 Jul 24 | Re: Continuations | 1 | MitchAlsup1 | |
16 Jul 24 | Re: Continuations | 1 | Lawrence D'Oliveiro | |
14 Jul 24 | Re: Continuations | 1 | BGB | |
13 Jul 24 | Re: Continuations | 1 | BGB | |
14 Jul 24 | Re: Continuations | 10 | Lawrence D'Oliveiro | |
15 Jul 24 | Re: Continuations | 7 | Thomas Koenig | |
15 Jul 24 | Re: Continuations | 6 | Thomas Koenig | |
16 Jul 24 | Re: Continuations | 4 | Thomas Koenig | |
16 Jul 24 | Re: Continuations | 2 | MitchAlsup1 | |
17 Jul 24 | Re: Continuations | 1 | Lawrence D'Oliveiro | |
17 Jul 24 | Re: Continuations | 1 | Lawrence D'Oliveiro | |
17 Jul 24 | Re: Continuations | 1 | John Dallman | |
16 Jul 24 | Re: Continuations | 1 | Lawrence D'Oliveiro | |
16 Jul 24 | Re: Continuations | 1 | John Levine | |
14 Jul 24 | Re: Continuations | 1 | George Neuner | |
14 Jul 24 | Re: Continuations | 92 | John Savard | |
14 Jul 24 | Re: Continuations | 1 | BGB | |
15 Jul 24 | Re: Continuations | 90 | Lawrence D'Oliveiro | |
16 Jul 24 | Re: Continuations | 89 | John Savard | |
16 Jul 24 | Re: Continuations | 2 | MitchAlsup1 | |
17 Jul 24 | Re: Continuations | 1 | Lawrence D'Oliveiro | |
16 Jul 24 | Re: Continuations | 86 | MitchAlsup1 | |
17 Jul 24 | Re: Continuations | 69 | John Savard | |
17 Jul 24 | Re: Continuations | 68 | MitchAlsup1 | |
17 Jul 24 | Re: Continuations | 67 | Thomas Koenig | |
17 Jul 24 | Re: Continuations | 1 | Thomas Koenig | |
17 Jul 24 | Re: Continuations | 1 | Michael S | |
17 Jul 24 | Re: Continuations | 37 | MitchAlsup1 | |
17 Jul 24 | Re: Continuations | 36 | Stephen Fuld | |
17 Jul 24 | Re: Continuations | 35 | MitchAlsup1 | |
17 Jul 24 | Re: Continuations | 22 | Stephen Fuld | |
18 Jul 24 | Re: Continuations | 8 | MitchAlsup1 | |
18 Jul 24 | Re: Continuations | 1 | Michael S | |
18 Jul 24 | Re: Continuations | 6 | MitchAlsup1 | |
19 Jul 24 | Re: Continuations | 1 | Stephen Fuld | |
21 Jul 24 | Re: Reservation stations [was Continuations] | 2 | Anton Ertl | |
21 Jul 24 | Re: Reservation stations [was Continuations] | 1 | MitchAlsup1 | |
21 Jul 24 | Re: Reservation stations [was Continuations] | 2 | MitchAlsup1 | |
22 Jul 24 | IPC (was: Reservation stations) | 1 | Anton Ertl | |
18 Jul 24 | Re: Continuations | 11 | Thomas Koenig | |
18 Jul 24 | Re: Continuations | 10 | Michael S | |
18 Jul 24 | Re: Continuations | 9 | Thomas Koenig | |
18 Jul 24 | Re: Continuations | 8 | Michael S | |
18 Jul 24 | Re: Continuations | 6 | Thomas Koenig | |
18 Jul 24 | Re: Continuations | 1 | Michael S | |
18 Jul 24 | Re: Continuations | 4 | Michael S | |
19 Jul 24 | Re: Continuations | 3 | Thomas Koenig | |
19 Jul 24 | Re: Continuations | 2 | Michael S | |
20 Jul 24 | Re: Continuations | 1 | Thomas Koenig | |
18 Jul 24 | Re: Continuations | 1 | MitchAlsup1 | |
18 Jul 24 | Re: Continuations | 2 | John Savard | |
18 Jul 24 | Re: Continuations | 1 | Thomas Koenig | |
18 Jul 24 | Re: Continuations | 6 | Thomas Koenig | |
18 Jul 24 | Re: Continuations | 5 | Michael S | |
18 Jul 24 | Re: Continuations | 4 | Michael S | |
18 Jul 24 | Re: Continuations | 3 | Thomas Koenig | |
18 Jul 24 | Re: Continuations | 2 | MitchAlsup1 | |
20 Jul 24 | Re: Continuations | 1 | Thomas Koenig | |
18 Jul 24 | Non-pipelined FDIV/SQRT (was: Continuations) | 3 | Stefan Monnier | |
18 Jul 24 | Re: Non-pipelined FDIV/SQRT | 1 | MitchAlsup1 | |
28 Jul 24 | Re: Non-pipelined FDIV/SQRT | 1 | Michael S | |
18 Jul 24 | Re: Continuations | 3 | MitchAlsup1 | |
28 Jul 24 | Re: Continuations | 2 | Paul A. Clayton | |
28 Jul 24 | Re: Continuations | 1 | Michael S | |
19 Jul 24 | Re: Continuations | 27 | Terje Mathisen | |
19 Jul 24 | Re: Continuations | 5 | Thomas Koenig | |
19 Jul 24 | Re: Continuations | 1 | Chris M. Thomasson | |
19 Jul 24 | Re: Continuations | 3 | MitchAlsup1 | |
20 Jul 24 | Re: Continuations | 1 | Terje Mathisen | |
20 Jul 24 | Re: Continuations | 1 | Thomas Koenig | |
19 Jul 24 | Re: Continuations | 21 | MitchAlsup1 | |
19 Jul 24 | Re: Continuations | 8 | Terje Mathisen | |
22 Jul 24 | Re: Continuations | 7 | Michael S | |
22 Jul 24 | Re: Continuations | 3 | MitchAlsup1 | |
22 Jul 24 | Re: Continuations | 2 | Michael S | |
23 Jul 24 | Re: Continuations | 1 | MitchAlsup1 | |
23 Jul 24 | Re: Continuations | 3 | Terje Mathisen | |
19 Jul 24 | Faster div or 1/sqrt approximations (was: Continuations) | 12 | Thomas Koenig | |
17 Jul 24 | Re: Continuations | 3 | Lawrence D'Oliveiro | |
17 Jul 24 | Re: Continuations | 12 | Stephen Fuld | |
17 Jul 24 | Re: fancy instructions, Continuations | 1 | John Levine | |
15 Jul 24 | Re: Continuations | 1 | wolfgang kern | |
15 Jul 24 | Re: pessimal storage allocation, Continuations | 3 | John Levine | |
15 Jul 24 | Re: Continuations | 1 | MitchAlsup1 | |
16 Jul 24 | Re: Continuations | 1 | Lynn Wheeler |
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