[9fans] make passive aggressive gcc
If you're using gcc 4.8.2 to compile ... anything, really ... but certainly Plan 9 or Inferno components, and those use for loops with arrays, be sure to include the compilation options -fno-strict-aliasing\ -fno-aggressive-loop-optimizations\ and it will save you some time and effort. It will save compilation time (not that you'll notice with that sluggard) because it won't fuss even more with your program, and it will save effort, because you won't have to debug simple loops that have bounds changed, are removed completely, or otherwise wrecked. You can find discussions of it elsewhere (which is how I found compiler options to stop it). I'd forgotten all about it until it surfaced again.
Re: [9fans] inequality testing in shell
On Sun Jun 14 14:12:13 PDT 2015, nsa...@gmail.com wrote: > Why doesn't the plan9 test program have features for checking > inequalities (i.e. greater than etc.)? > What do you guys do when you want to test for inequality? > > Maybe the most convenient way to do that in the shell would be if I > made two tiny programs, lt & gt which would check their two arguments. to be more pedantic than necessary, test is not part of the plan 9 shell. the ~ operator is the way to test for (string) equality or inequality. ! is shell negation, so for non-negative integral x, ~ $x [1-3] -> x < 4 ! ~ $x [1-3]-> x >= 4 the shell doesn't understand numbers. outside the shell, hoc or awk are alternatives to test - erik
Re: [9fans] make passive aggressive gcc
On Mon, 15 Jun 2015 09:21:56 +0100 Charles Forsyth wrote: > If you're using gcc 4.8.2 to compile ... anything, really ... but certainly > Plan 9 or Inferno components, > and those use for loops with arrays, be sure to include the compilation > options > -fno-strict-aliasing\ > -fno-aggressive-loop-optimizations\ > and it will save you some time and effort. > It will save compilation time (not that you'll notice with that sluggard) > because it won't > fuss even more with your program, and it will save effort, because you > won't have > to debug simple loops that have bounds changed, are removed completely, or > otherwise wrecked. > You can find discussions of it elsewhere (which is how I found compiler > options to stop it). > I'd forgotten all about it until it surfaced again. Thanks. Reminds me I liked gcc when it applied very few optimizations. I guess it must have been focused on machine-specific optimizations back in 2007/2008. I had a cpu newer than gcc had support for, and compilation was actually quick. Anyone know if -O0 is a reasonable option these days? (I mean tested well enough to be reasonably bug-free.) -- Developing the austere intellectual discipline of keeping things sufficiently simple is in this environment a formidable challenge, both technically and educationally. -- Dijstraka, EWD898, 1984
Re: [9fans] make passive aggressive gcc
Ugh, I know. It caused Judy arrays to segfault a lot. >From my personal experience, Clang does *not* have this problem. On June 15, 2015 3:21:56 AM CDT, Charles Forsyth wrote: >If you're using gcc 4.8.2 to compile ... anything, really ... but >certainly >Plan 9 or Inferno components, >and those use for loops with arrays, be sure to include the compilation >options >-fno-strict-aliasing\ >-fno-aggressive-loop-optimizations\ >and it will save you some time and effort. >It will save compilation time (not that you'll notice with that >sluggard) >because it won't >fuss even more with your program, and it will save effort, because you >won't have >to debug simple loops that have bounds changed, are removed completely, >or >otherwise wrecked. >You can find discussions of it elsewhere (which is how I found compiler >options to stop it). >I'd forgotten all about it until it surfaced again. -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
Re: [9fans] make passive aggressive gcc
On Mon, Jun 15, 2015 at 3:41 PM, Ethan Grammatikidis wrote: > On Mon, 15 Jun 2015 09:21:56 +0100 > Charles Forsyth wrote: > >> If you're using gcc 4.8.2 to compile ... anything, really ... but certainly >> Plan 9 or Inferno components, >> and those use for loops with arrays, be sure to include the compilation >> options >> -fno-strict-aliasing\ >> -fno-aggressive-loop-optimizations\ >> and it will save you some time and effort. >> It will save compilation time (not that you'll notice with that sluggard) >> because it won't >> fuss even more with your program, and it will save effort, because you >> won't have >> to debug simple loops that have bounds changed, are removed completely, or >> otherwise wrecked. >> You can find discussions of it elsewhere (which is how I found compiler >> options to stop it). >> I'd forgotten all about it until it surfaced again. > > Thanks. Reminds me I liked gcc when it applied very few optimizations. > I guess it must have been focused on machine-specific optimizations > back in 2007/2008. I had a cpu newer than gcc had support for, and > compilation was actually quick. Anyone know if -O0 is a reasonable > option these days? (I mean tested well enough to be reasonably > bug-free.) I've recenetly seen a few examples where -O0 would produce a segfaulting executable, while any other -Ox would work fine. Also, I don't know what gcc authors are smoking, but "strcpy(tmp, "what.");" will be compiled to a few mov instructions with -O0, while -Os still has a call to strcpy, just the way it *should* always be, imho. I just checked this once again (gcc-4.8.4) and it still applies.
Re: [9fans] make passive aggressive gcc
On Mon, 15 Jun 2015 16:56:28 +0200 Siarhei Zirukin wrote: > On Mon, Jun 15, 2015 at 3:41 PM, Ethan Grammatikidis > wrote: > > On Mon, 15 Jun 2015 09:21:56 +0100 > > Charles Forsyth wrote: > > > >> If you're using gcc 4.8.2 to compile ... anything, really ... but certainly > >> Plan 9 or Inferno components, > >> and those use for loops with arrays, be sure to include the compilation > >> options > >> -fno-strict-aliasing\ > >> -fno-aggressive-loop-optimizations\ > >> and it will save you some time and effort. > >> It will save compilation time (not that you'll notice with that sluggard) > >> because it won't > >> fuss even more with your program, and it will save effort, because you > >> won't have > >> to debug simple loops that have bounds changed, are removed completely, or > >> otherwise wrecked. > >> You can find discussions of it elsewhere (which is how I found compiler > >> options to stop it). > >> I'd forgotten all about it until it surfaced again. > > > > Thanks. Reminds me I liked gcc when it applied very few optimizations. > > I guess it must have been focused on machine-specific optimizations > > back in 2007/2008. I had a cpu newer than gcc had support for, and > > compilation was actually quick. Anyone know if -O0 is a reasonable > > option these days? (I mean tested well enough to be reasonably > > bug-free.) > > I've recenetly seen a few examples where -O0 would produce a > segfaulting executable, while any other -Ox would work fine. > Also, I don't know what gcc authors are smoking, but "strcpy(tmp, > "what.");" will be compiled to a few mov instructions with -O0, while > -Os still has a call to strcpy, just the way it *should* always be, > imho. I just checked this once again (gcc-4.8.4) and it still applies. > So -O0 hasn't improved since 2008 then. Time to switch to clang, I guess. -- Developing the austere intellectual discipline of keeping things sufficiently simple is in this environment a formidable challenge, both technically and educationally. -- Dijstraka, EWD898, 1984
Re: [9fans] make passive aggressive gcc
> > I don't know what gcc authors are smoking, but "strcpy(tmp, > "what.");" will be compiled to a few mov instructions with -O0, while > -Os still has a call to strcpy, just the way it *should* always be, > imho. not that it's any excuse, but -fno-builtin helps. On Mon, Jun 15, 2015 at 4:56 PM, Siarhei Zirukin wrote: > On Mon, Jun 15, 2015 at 3:41 PM, Ethan Grammatikidis > wrote: > > On Mon, 15 Jun 2015 09:21:56 +0100 > > Charles Forsyth wrote: > > > >> If you're using gcc 4.8.2 to compile ... anything, really ... but > certainly > >> Plan 9 or Inferno components, > >> and those use for loops with arrays, be sure to include the compilation > >> options > >> -fno-strict-aliasing\ > >> -fno-aggressive-loop-optimizations\ > >> and it will save you some time and effort. > >> It will save compilation time (not that you'll notice with that > sluggard) > >> because it won't > >> fuss even more with your program, and it will save effort, because you > >> won't have > >> to debug simple loops that have bounds changed, are removed completely, > or > >> otherwise wrecked. > >> You can find discussions of it elsewhere (which is how I found compiler > >> options to stop it). > >> I'd forgotten all about it until it surfaced again. > > > > Thanks. Reminds me I liked gcc when it applied very few optimizations. > > I guess it must have been focused on machine-specific optimizations > > back in 2007/2008. I had a cpu newer than gcc had support for, and > > compilation was actually quick. Anyone know if -O0 is a reasonable > > option these days? (I mean tested well enough to be reasonably > > bug-free.) > > I've recenetly seen a few examples where -O0 would produce a > segfaulting executable, while any other -Ox would work fine. > Also, I don't know what gcc authors are smoking, but "strcpy(tmp, > "what.");" will be compiled to a few mov instructions with -O0, while > -Os still has a call to strcpy, just the way it *should* always be, > imho. I just checked this once again (gcc-4.8.4) and it still applies. > >
[9fans] Wildly off-topic
As the subject line says, wildly off-topic. But some-one here might know the answer, and it’s been bothering me. Such are my failings, I’ve been watching the second series of “Halt and Catch Fire” in order to catch up with what the kids are up to these days. In the second episode one of the characters opens what looks like a copy of K&R first edition, but the cover is blue. I thought that the colour correction on my TV might be deceiving me, or possibly the vertical hold was on the fritz, but he did it again in the third episode, and the cover was still blue. So my question is, did there ever exist an edition of K&R in that colour scheme, or is gcc to blame for the inaccuracy?
Re: [9fans] Wildly off-topic
> So my question is, did there ever exist an edition of K&R in that > colour scheme, or is gcc to blame for the inaccuracy? The old web page for the book had a nice collection of covers from around the world: http://9p.io/cm/cs/cbook/index.html sl
Re: [9fans] Wildly off-topic
It's always GCC. On Mon, Jun 15, 2015 at 6:06 PM, Andrew Simmons wrote: > As the subject line says, wildly off-topic. But some-one here might know > the answer, and it’s been bothering me. > > Such are my failings, I’ve been watching the second series of “Halt and > Catch Fire” in order to catch up with what the kids are up to these days. > In the second episode one of the characters opens what looks like a copy of > K&R first edition, but the cover is blue. I thought that the colour > correction on my TV might be deceiving me, or possibly the vertical hold > was on the fritz, but he did it again in the third episode, and the cover > was still blue. > > So my question is, did there ever exist an edition of K&R in that colour > scheme, or is gcc to blame for the inaccuracy? > -- Ryan [ERROR]: Your autotools build scripts are 200 lines longer than your program. Something’s wrong. http://kirbyfan64.github.io/
Re: [9fans] Wildly off-topic
On Tue, 16 Jun 2015 11:06:48 +1200 Andrew Simmons wrote: > As the subject line says, wildly off-topic. But some-one here might know = > the answer, and it=E2=80=99s been bothering me. > > Such are my failings, I=E2=80=99ve been watching the second series of = > =E2=80=9CHalt and Catch Fire=E2=80=9D in order to catch up with what the = > kids are up to these days. In the second episode one of the characters = > opens what looks like a copy of K&R first edition, but the cover is = > blue. I thought that the colour correction on my TV might be deceiving = > me, or possibly the vertical hold was on the fritz, but he did it again = > in the third episode, and the cover was still blue. > > So my question is, did there ever exist an edition of K&R in that colour = > scheme, or is gcc to blame for the inaccuracy?= Amazon trade ins of The C programming Language shows a cyan blue cover -- it says "Eastern Economic Edition" and it is the second edition. http://www.amazon.com/Programming-Language-Brian-W-Kernighan/dp/8120305965/ref=sr_1_2?s=tradein-aps&srs=9187220011&ie=UTF8&qid=1434409938&sr=8-2&keywords=the+c+programming+language
Re: [9fans] Wildly off-topic
Thanks, but it seems as if that web page is for the 2nd edition. I have two copies of this, one of which is much thicker than the other, despite having the same number of pages, but that’s a different wildly off-topic topic. I used to have a copy of the 1st edition, and I’m sure that the background colour was white. Did there ever exist a version with a blue cover? Also, I think that “It’s a fair cop, but gcc is to blame” should be an adequate defence in any court of law. > On Jun 16, 2015, at 11:13 am, s...@9front.org wrote: > >> So my question is, did there ever exist an edition of K&R in that >> colour scheme, or is gcc to blame for the inaccuracy? > > The old web page for the book had a nice collection of covers from > around the world: > > http://9p.io/cm/cs/cbook/index.html > > sl >
Re: [9fans] Wildly off-topic
Quoting Andrew Simmons : So my question is, did there ever exist an edition of K&R in that Quoting Andrew Simmons : Thanks, but it seems as if that web page is for the 2nd edition. ok, still yes. The linked page is for all editions. khm
Re: [9fans] Wildly off-topic
ISTR the first edition cover was green on white, but that could have been a reprint (or a faulty memory). Steve On Mon, Jun 15, 2015 at 6:28 PM, Andrew Simmons wrote: > Thanks, but it seems as if that web page is for the 2nd edition. I have > two copies of this, one of which is much thicker than the other, despite > having the same number of pages, but that’s a different wildly off-topic > topic. I used to have a copy of the 1st edition, and I’m sure that the > background colour was white. Did there ever exist a version with a blue > cover? > > Also, I think that “It’s a fair cop, but gcc is to blame” should be an > adequate defence in any court of law. > > > > On Jun 16, 2015, at 11:13 am, s...@9front.org wrote: > > > >> So my question is, did there ever exist an edition of K&R in that > >> colour scheme, or is gcc to blame for the inaccuracy? > > > > The old web page for the book had a nice collection of covers from > > around the world: > > > > http://9p.io/cm/cs/cbook/index.html > > > > sl > > > > >
Re: [9fans] Wildly off-topic
On Tue, Jun 16, 2015, at 04:52 AM, Bakul Shah wrote: > On Tue, 16 Jun 2015 11:06:48 +1200 Andrew Simmons > wrote: > > As the subject line says, wildly off-topic. But some-one here might know = > > the answer, and it=E2=80=99s been bothering me. > > > > Such are my failings, I=E2=80=99ve been watching the second series of = > > =E2=80=9CHalt and Catch Fire=E2=80=9D in order to catch up with what the = > > kids are up to these days. In the second episode one of the characters = > > opens what looks like a copy of K&R first edition, but the cover is = > > blue. I thought that the colour correction on my TV might be deceiving = > > me, or possibly the vertical hold was on the fritz, but he did it again = > > in the third episode, and the cover was still blue. > > > > So my question is, did there ever exist an edition of K&R in that colour = > > scheme, or is gcc to blame for the inaccuracy?= > > Amazon trade ins of The C programming Language shows a cyan > blue cover -- it says "Eastern Economic Edition" and it is the > second edition. Yes, I can confirm that. It is sold here in India. It used to be the same white cover as the international edition (my copy from 1993, eastern economy edition, has a white cover). -- Ramakrishnan
Re: [9fans] Wildly off-topic
My copy of the first edition from 1978 has a white cover with blue lettering. Kim
Re: [9fans] Wildly off-topic
> On Jun 16, 2015, at 3:48 pm, Kim Shrier wrote: > > My copy of the first edition from 1978 has a white cover with blue lettering. > > Kim > > Mine did too. The one on the show is clearly not the second edition, but has a light blue cover with darker blue lettering, apart from the “C”, which is red. Tragic obsessive, me??? I blame gcc.
Re: [9fans] Wildly off-topic
at one point there was a web page with images of many (maybe all) K&R C covers from various prints and translations. i think it was a page that dmr had created (or perhaps bwk, i can't remember exactly). i can't seem to find it now. >> On Jun 16, 2015, at 3:48 pm, Kim Shrier wrote: >> >> My copy of the first edition from 1978 has a white cover with blue lettering. >> >> Kim >> >> > > Mine did too. The one on the show is clearly not the second edition, but has > a light blue cover with darker blue lettering, apart from the “C”, which is > red. Tragic obsessive, me??? I blame gcc.
