By: Michael S (already5chosen.delete@this.yahoo.com), February 22, 2019 4:15 am
Room: Moderated Discussions
Stoffels (prem.delete@this.b.il) on February 21, 2019 11:21 pm wrote:
> Linus Torvalds (torvalds.delete@this.linux-foundation.org) on February 21, 2019 3:27 pm wrote:
> > Because it's just very frustrating to chase bugs that you can't reproduce locally. Particularly
> > if they are in random infrastructure that you don't know (and perhaps not even "bugs" - just different
> > behavior in basic libraries, perhaps just due to implementation-defined differences).
>
> Yup.
>
> Locally running (x86) verification app gave perfect results; cross-compiled (ARM) app
> running the exact same (copy-pasted) C-code on device gave very weird results.
> The problem: casting negative floats (below -1) to unsigned int
That's reliance on undefined behavior. Could have easily happened on x86 as well, with different compiler, or with different flags on the same compiler or even with the next version of the same compiler with the same flags.
> Linus Torvalds (torvalds.delete@this.linux-foundation.org) on February 21, 2019 3:27 pm wrote:
> > Because it's just very frustrating to chase bugs that you can't reproduce locally. Particularly
> > if they are in random infrastructure that you don't know (and perhaps not even "bugs" - just different
> > behavior in basic libraries, perhaps just due to implementation-defined differences).
>
> Yup.
>
> Locally running (x86) verification app gave perfect results; cross-compiled (ARM) app
> running the exact same (copy-pasted) C-code on device gave very weird results.
> The problem: casting negative floats (below -1) to unsigned int
That's reliance on undefined behavior. Could have easily happened on x86 as well, with different compiler, or with different flags on the same compiler or even with the next version of the same compiler with the same flags.
| Topic | Posted By | Date |
|---|---|---|
| ARM announces Ares | nobody in particular | 2019/02/20 08:35 AM |
| ARM announces Ares | Adrian | 2019/02/20 08:39 AM |
| ARM announces Ares | dmcq | 2019/02/20 10:03 AM |
| ARM announces Ares | Michael S | 2019/02/20 10:41 AM |
| ARM announces Ares | dmcq | 2019/02/20 12:49 PM |
| ARM announces Ares | Michael S | 2019/02/20 01:21 PM |
| ARM announces Ares | dmcq | 2019/02/20 02:01 PM |
| ARM announces Ares | Wilco | 2019/02/20 02:31 PM |
| ARM announces Ares | dmcq | 2019/02/20 03:16 PM |
| ARM announces Ares | Wilco | 2019/02/20 03:49 PM |
| ARM announces Ares | dmcq | 2019/02/20 04:09 PM |
| ARM announces Ares | Wilco | 2019/02/20 04:45 PM |
| ARM announces Ares | nobody in particular | 2019/02/20 04:55 PM |
| ARM announces Ares | Dan Fay | 2019/02/20 05:44 PM |
| ARM announces Ares | Wilco | 2019/02/20 07:06 PM |
| ARM announces Ares | Dan Fay | 2019/02/21 08:27 AM |
| ARM announces Ares | dmcq | 2019/02/20 05:49 PM |
| ARM announces Ares | Wilco | 2019/02/20 06:40 PM |
| ARM announces Ares | Charles | 2019/02/21 02:16 AM |
| ARM announces Ares | Michael S | 2019/02/21 02:26 AM |
| ARM announces Ares | anon | 2019/02/20 08:55 PM |
| ARM announces Ares | JS | 2019/02/21 12:59 AM |
| *has not hasn't (NT) | JS | 2019/02/21 01:01 AM |
| ARM announces Ares | Salvatore De Dominicis | 2019/02/21 07:05 AM |
| Definitions of RISC | Brendan | 2019/02/21 10:07 AM |
| Definitions of RISC | Michael S | 2019/02/21 10:16 AM |
| PDP-8 Not Usually Considered RISC | Mark Roulo | 2019/02/21 02:10 PM |
| PDP-8 Not Usually Considered RISC | rwessel | 2019/02/21 07:13 PM |
| Definitions of RISC | Adrian | 2019/02/21 02:42 PM |
| Definitions of RISC (nod to John Mashey and comp.arch) | wumpus | 2019/02/21 06:29 PM |
| Definitions of RISC (nod to John Mashey and comp.arch) | none | 2019/02/22 12:32 AM |
| Definitions of RISC (nod to John Mashey and comp.arch) | Michael S | 2019/02/22 04:28 AM |
| Definitions of RISC (nod to John Mashey and comp.arch) | none | 2019/02/22 08:01 AM |
| ARM announces Ares | lockederboss | 2019/02/20 09:56 AM |
| stability? (NT) | anonymous2 | 2019/02/20 10:01 AM |
| ARM announces Ares | dmcq | 2019/02/20 10:05 AM |
| ARM announces Ares | Groo | 2019/02/20 10:11 AM |
| ARM announces Ares | Andrei Frumusanu | 2019/02/20 11:49 AM |
| ARM announces Ares | Linus Torvalds | 2019/02/20 10:36 AM |
| ARM announces Ares | Michael S | 2019/02/20 10:54 AM |
| ARM announces Ares | Geoff Langdale | 2019/02/20 03:07 PM |
| ARM announces Ares | dmcq | 2019/02/20 03:32 PM |
| ARM announces Ares | none | 2019/02/21 12:03 AM |
| That last line should have been removed :-) (NT) | none | 2019/02/21 12:04 AM |
| ARM announces Ares | Michael S | 2019/02/21 01:47 AM |
| ARM announces Ares | none | 2019/02/21 03:59 AM |
| ARM announces Ares | Michael S | 2019/02/21 04:45 AM |
| ARM announces Ares | dmcq | 2019/02/21 05:18 AM |
| ARM announces Ares | Simon Farnsworth | 2019/02/22 09:43 AM |
| ARM announces Ares | anon | 2019/02/20 09:27 PM |
| ARM announces Ares | Michael S | 2019/02/21 01:53 AM |
| ARM announces Ares | Linus Torvalds | 2019/02/21 09:03 AM |
| ARM announces Ares | Michael S | 2019/02/21 09:35 AM |
| ARM announces Ares | Michael S | 2019/02/21 09:51 AM |
| ARM announces Ares | Foo_ | 2019/02/21 02:40 PM |
| ARM announces Ares | aaron spink | 2019/02/21 03:56 PM |
| ARM announces Ares | Linus Torvalds | 2019/02/21 04:27 PM |
| ARM announces Ares | Stoffels | 2019/02/22 12:21 AM |
| ARM announces Ares | Michael S | 2019/02/22 04:15 AM |
| ARM announces Ares | Simon Farnsworth | 2019/02/22 09:41 AM |
| ARM announces Ares | none | 2019/02/22 10:30 AM |
| In other words: nobody will ever get fired for choosing x86 (NT) | Gabriele Svelto | 2019/02/24 01:32 PM |
| In other words: nobody will ever get fired for choosing x86 | Simon Farnsworth | 2019/02/25 04:53 AM |
| ARM announces Ares | Foo_ | 2019/02/22 02:52 AM |
| ARM announces Ares | Gabriele Svelto | 2019/02/24 01:31 PM |
| ARM announces Ares | Maynard Handley | 2019/02/25 03:57 AM |
| ARM announces Ares | Gabriele Svelto | 2019/02/25 04:21 AM |
| ARM announces Ares | Michael S | 2019/02/25 04:58 AM |
| ARM announces Ares | nobody in particular | 2019/02/25 05:21 AM |
| ARM announces Ares | Adrian | 2019/02/26 08:02 AM |
| ARM announces Ares | Maynard Handley | 2019/02/26 12:32 AM |
| ARM announces Ares | Gabriele Svelto | 2019/02/26 12:14 PM |
| ARM announces Ares | David Hess | 2019/03/19 05:34 PM |
| ARM announces Ares | none | 2019/02/26 01:34 AM |
| ARM announces Ares | Gabriele Svelto | 2019/02/26 12:16 PM |
| ARM announces Ares | none | 2019/02/27 12:19 AM |
| ARM announces Ares | end of an era | 2019/02/24 03:18 PM |
| Word salad bot strikes again (NT) | nanon | 2019/02/25 12:26 AM |
| ARM announces Ares | hobel | 2019/02/25 02:10 AM |
| ARM announces Ares | Michael S | 2019/02/25 02:52 AM |
| ARM announces Ares | hobel | 2019/02/25 10:48 AM |
| ARM announces Ares | Andrew Clough | 2019/02/25 02:07 PM |
| ARM announces Ares | Maynard Handley | 2019/02/26 12:38 AM |
| ARM announces Ares | John Yates | 2019/02/26 03:43 PM |
| ARM announces Ares | Howard Chu | 2019/02/27 06:55 AM |
| ARM announces Ares | David Hess | 2019/03/19 05:22 PM |
| ARM announces Ares | David Hess | 2019/03/19 04:54 PM |
| ARMY announces Ares | dmcq | 2019/03/20 03:12 AM |
| ARMY announces Ares | David Hess | 2019/03/20 05:47 AM |
| ARMY announces Ares | dmcq | 2019/03/20 06:05 AM |
| ARM announces Ares | Groo | 2019/02/21 10:23 AM |
| ARM announces Ares | Michael S | 2019/02/21 10:29 AM |
| ARM announces Ares | David Hess | 2019/03/19 05:44 PM |
| ARM announces Ares | juanrga | 2019/02/21 11:52 AM |
| ARM announces Ares | anon | 2019/02/21 08:19 PM |
| ARM announces Ares | hobel | 2019/02/22 03:40 AM |
| software ecosystems | RichardC | 2019/02/21 04:31 PM |
| software ecosystems | Foo_ | 2019/02/22 03:15 AM |
| ARM announces Ares | dmcq | 2019/02/21 05:31 PM |
| + on hyperscaling | dmcq | 2019/02/22 08:23 AM |
| + on hyperscaling | Maynard Handley | 2019/02/22 08:38 AM |
| + on hyperscaling | juanrga | 2019/02/22 11:57 AM |
| + on hyperscaling | dmcq | 2019/02/22 08:23 AM |
| sorry duplicate | dmcq | 2019/02/22 08:26 AM |
| ARM announces Ares | anon | 2019/02/21 08:34 PM |
| ARM announces Ares | Brett | 2019/02/21 10:20 PM |
| ARM announces Ares | A. Wilcox | 2019/02/22 03:52 PM |
| ARM announces Ares | Doug S | 2019/02/20 03:30 PM |
| ARM announces Ares | dmcq | 2019/02/20 04:14 PM |
| ARM announces Ares | Doug S | 2019/02/21 08:40 AM |
| ARM announces Ares | aaron spink | 2019/02/21 04:05 PM |
| ARM announces Ares | Maynard Handley | 2019/02/22 08:48 AM |
| ARM announces Ares | juanrga | 2019/02/21 02:28 AM |
| ARM announces Ares | Michael S | 2019/02/21 03:25 AM |
| ARM announces Ares | juanrga | 2019/02/22 04:09 AM |
| ARM announces Ares | Maynard Handley | 2019/02/22 08:51 AM |
| ARM announces Ares | David Soul | 2019/02/22 11:47 AM |
| ARM announces Ares | juanrga | 2019/02/22 12:23 PM |
| Chicken or egg, both. | Brett | 2019/02/22 02:21 PM |
| Chicken or egg, both. | David Soul | 2019/02/22 06:05 PM |
| Chicken or egg, both. | Brett | 2019/02/22 09:55 PM |
| ARM sales | juanrga | 2019/02/23 03:55 AM |
| ARM sales | aaron spink | 2019/02/23 08:47 AM |
| Chicken or egg, both. | Ronald Maas | 2019/02/23 06:33 PM |
| Chicken or egg, both. | Magagop | 2019/02/24 11:18 PM |
| why not? (NT) | Michael S | 2019/02/25 02:03 AM |
| why not? | Not the parent | 2019/02/25 10:36 AM |
| why not? | Michael S | 2019/02/25 10:43 AM |
| why not? | dmcq | 2019/02/25 11:35 AM |
| why not? | Michael S | 2019/02/25 12:03 PM |
| why not? | dmcq | 2019/02/25 12:29 PM |
| why not? | Not the parent | 2019/02/26 10:08 AM |
| why not? | Doug S | 2019/02/26 12:05 PM |
| why not? | Not the parent | 2019/02/27 04:51 AM |
| why not? | Doug S | 2019/02/27 12:15 PM |
| why not? | Not the parent | 2019/02/28 01:43 AM |
| why not? | anon | 2019/02/26 11:22 PM |
| why not? | Not the parent | 2019/02/27 04:59 AM |
| why not? | anon | 2019/02/27 06:42 AM |
| why not? | Magagop | 2019/02/27 03:31 PM |
| why not? | anon | 2019/02/27 05:02 PM |
| why not? | dmcq | 2019/02/27 05:25 PM |
| why not? | anon | 2019/02/27 05:56 PM |
| why not? | dmcq | 2019/02/27 06:19 PM |
| why not? | anon | 2019/02/27 06:46 PM |
| why not? | Wilco | 2019/02/28 05:49 AM |
| why not? | Jukka Larja | 2019/02/28 07:02 AM |
| why not? | Michael S | 2019/02/28 08:32 AM |
| why not? | Wilco | 2019/02/28 09:40 AM |
| why not? | Doug S | 2019/02/28 10:13 AM |
| why not? | Foo_ | 2019/03/01 07:35 AM |
| why not? | Doug S | 2019/03/01 11:05 AM |
| why not? | anon | 2019/03/01 02:32 PM |
| why not? | dmcq | 2019/03/01 03:13 PM |
| why not? | anon | 2019/03/01 04:13 PM |
| why not? | dmcq | 2019/03/02 03:56 AM |
| why not? | anon | 2019/03/02 10:09 AM |
| why not? | dmcq | 2019/03/02 10:41 AM |
| why not? | anon | 2019/03/02 12:19 PM |
| why not? | dmcq | 2019/03/03 03:48 AM |
| why not? | Doug S | 2019/03/02 04:53 PM |
| why not? | Michael S | 2019/03/02 05:06 PM |
| why not? | Doug S | 2019/03/03 12:54 AM |
| why not? | Michael S | 2019/03/03 02:58 AM |
| why not? | anon | 2019/03/03 05:35 AM |
| why not? | dmcq | 2019/03/03 06:33 AM |
| I considired dry humor a Brittish specialty. It seems, I was wrong about it. (NT) | Michael S | 2019/03/03 06:39 AM |
| why not? | anon | 2019/03/03 10:13 AM |
| why not? | Michael S | 2019/03/03 12:41 PM |
| why not? | dmcq | 2019/03/03 01:21 PM |
| why not? | anon | 2019/03/03 04:15 PM |
| why not? | anon | 2019/02/28 08:38 PM |
| why not? | Not the parent | 2019/02/28 01:48 AM |
| strawman (NT) | anon | 2019/02/28 08:31 PM |
| why not? | Michael S | 2019/02/27 03:53 AM |
| why not? | Not the parent | 2019/02/27 05:26 AM |
| why not? | Michael S | 2019/02/27 05:42 AM |
| why not? | dmcq | 2019/02/27 05:49 AM |
| why not? | Michael S | 2019/02/27 06:21 AM |
| why not? | dmcq | 2019/02/27 07:15 AM |
| Selling at multiple layers | Paul A. Clayton | 2019/02/27 11:25 AM |
| Selling at multiple layers | Doug S | 2019/02/27 12:45 PM |
| Selling at multiple layers | Paul A. Clayton | 2019/02/27 02:32 PM |
| Selling at multiple layers | Doug S | 2019/02/27 04:04 PM |
| Paul A. Clayton | 2019/02/27 07:06 PM | |
| Arm reference board? | Simon Farnsworth | 2019/02/28 12:34 PM |
| why not? | Doug S | 2019/02/27 12:46 PM |
| why not? (NT) | la mama de murgay | 2019/02/25 10:22 PM |
| Chicken or egg, both. | Ronald Maas | 2019/02/25 01:23 PM |
| ARM announces Ares | Gabriele Svelto | 2019/02/24 03:07 PM |
| ARM announces Ares | juanrga | 2019/03/02 05:40 AM |
| ARM announces Ares | Gabriele Svelto | 2019/03/02 08:08 AM |
| ARM announces Ares | dmcq | 2019/03/02 10:10 AM |
| ARM announces Ares | hobel | 2019/02/22 04:33 PM |
| ARM announces Ares | David Soul | 2019/02/22 06:20 PM |
| Troll | Doug S | 2019/02/23 01:37 AM |
| Troll | David Soul | 2019/02/23 08:59 AM |
| ARM announces Ares | Ennis | 2019/02/23 02:18 AM |
| ARM announces Ares | Foo_ | 2019/02/23 02:38 AM |
| ARM announces Ares | anon | 2019/02/23 03:46 AM |
| ARM announces Ares | dmcq | 2019/02/23 05:41 AM |
| ARM announces Ares | nobody in particular | 2019/02/26 03:58 AM |
| expensive | anonymous2 | 2019/02/27 12:46 AM |
| ARM announces Ares | Howard Chu | 2019/02/27 07:19 AM |
| ARM announces Ares | Howard Chu | 2019/02/27 07:21 AM |
| ARM announces Ares | dmcq | 2019/02/27 07:57 AM |
| ARM announces Ares | Jukka Larja | 2019/02/27 08:11 AM |
| ARM announces Ares | Michael S | 2019/02/27 08:16 AM |
| ARM announces Ares | Doug S | 2019/02/27 12:49 PM |
| ARM announces Ares | Michael S | 2019/02/27 01:43 PM |
| ARM announces Ares | Doug S | 2019/02/27 04:06 PM |
| ARM announces Ares | Gian-Carlo Pascutto | 2019/02/28 05:00 AM |
| ARM announces Ares | Gian-Carlo Pascutto | 2019/02/28 05:02 AM |
| ARM announces Ares | Michael S | 2019/03/01 03:47 AM |
| death by a thousand cuts | Michael S | 2019/03/01 07:27 AM |
| death by a thousand cuts | Foo_ | 2019/03/01 07:37 AM |
| death by a thousand cuts | dmcq | 2019/03/01 12:10 PM |
| ARM announces Ares | Jukka Larja | 2019/02/28 06:31 AM |
| ARM announces Ares | Howard Chu | 2019/02/28 09:17 AM |
| ARM announces Ares | Gabriele Svelto | 2019/02/28 03:02 PM |
| ARM announces Ares | aaron spink | 2019/03/01 01:19 AM |
| ARM announces Ares | Andrew Clough | 2019/02/28 11:32 AM |
| ARM announces Ares | Andrew Clough | 2019/02/28 11:33 AM |
| ARM announces Ares | Foo_ | 2019/03/01 01:55 AM |
| ARM announces Ares | Jukka Larja | 2019/03/01 05:40 AM |
| ARM announces Ares | Howard Chu | 2019/02/27 08:45 AM |
| ARM announces Ares | dmcq | 2019/02/27 09:17 AM |
| ARM announces Ares | dmcq | 2019/02/27 09:21 AM |
| ARM announces Ares | Howard Chu | 2019/02/27 04:03 PM |
| ARM announces Ares | Jukka Larja | 2019/02/28 06:03 AM |
| ARM announces Ares | none | 2019/02/27 11:49 PM |
| ARM announces Ares | Howard Chu | 2019/02/28 04:26 AM |
| ARM announces Ares | Peter E. Fry | 2019/02/28 07:31 PM |
| ARM announces Ares | Adrian | 2019/02/28 10:09 PM |
| ARM announces Ares | Gabriele Svelto | 2019/03/02 12:56 AM |
| ARM announces Ares | Howard Chu | 2019/03/02 10:05 AM |
| ARM announces Ares | Gabriele Svelto | 2019/03/02 02:31 PM |
