8 ms·

GCC 9.3

112 points by lelf 7y ago

enriquto 7y ago
I wonder which of my "pet" virtual machines will hit it first: slackware or voidlinux ?
- Aaronstotle 7y ago
  Out of curiosity, what do you do with either of these "pet" machines? I always have an idea to make a virtual machine cluster, or something similar, but I haven't taken the plunge yet.
  - enriquto 7y ago
    I find them very useful for testing codes, as a sort of rapid-response travis. I run a script that pulls any new modification into each of my five "pets" (openbsd, slackware, freebsd, voidlinux+musl, dragonflybsd) and runs the tests. Since the systems are so different, it is very easy to break something. Since you notice it immediately (and not after waiting 1 minute for the travis answer) you develop a sense for avoiding non-portable things.
- azinman2 7y ago
  Slackware... they still active? No new stable builds in 4 years but seems to get security updates curiously. Their store leads to an error page in what looks like Chinese, confusingly.
  - smabie 7y ago
    http://www.slackware.com/changelog/current.php?cpu=x86_64 http://www.slackware.com/changelog/current.php?cpu=x86_64 The changelog seems to be, uhh, changing, so that's good I guess. I'm not sure they have many users left though.
    - smhenderson 7y ago
      We're around and it gained a bit more attention during a recent system wide change to many, more mainstream, distros that I'm sure most people here on HN don't really want to talk about (again). I like it because it leans more closely to traditional BSD systems than System V variants like Red Hat.
  - charlesdaniels 7y ago
    Slackware still lives. I'm running it on my daily driver right now. I actually just started using Slackware a few months ago too, so it's gained at least one new user in the last 12 months. Many updates are pushed to https://slackbuilds.org/ https://slackbuilds.org/ every week. Things definitely seem to move slower than on other OSes, but I much prefer it that way. I still run a supported LTS kernel and a supported LTS Firefox release; as long as security updates keep coming I don't feel the need to upgrade to newer software by and large.
  - smhenderson 7y ago
    The store thing is a sad state of affairs. Basically, as I understand it, the store was not run by Patrick Volkerding but by a third party that agreed to share profits with him from sales of Slackware branded merchandise. Patrick states that after a few years and much review he was basically being ripped off by them and withdrew permission for them to continue. Although helped by many volunteers Slackware is mostly a one man show and Patrick's income from the project was basically drawing down to zero. It seems to be a long, drawn out affair and I'm trying to come across as neutral here as I'm sure I don't have all the information. But I'll admit some bias as I started my life with Linux using Slackware from a CD that came with a book about Linux, I think in 1994, maybe early 1995. I switched to more mainstream distros at some point based on me using them at various jobs but always liked the idea of Slackware (the most BSD like Linux!). And I'm posting this from a laptop running -current. Yes, 15 has been a long time coming but Patrick continues to publish updates and the Slackware Security mailing list is alive and active. I'm off topic here so I'll wind this up with a note that the GCC package for Slackware Current is gcc-9.2.0-i586-4.txz. So I'm sure 9.3 will be coming along soon, though not as quickly as with some other distros. For those interested in more about the store I found the most relevant information here[1] when I last went looking for a way to contribute money to the project (i.e. to Patrick). [1]https://www.linuxquestions.org/questions/slackware-14/donating-to-slackware-4175634729/ https://www.linuxquestions.org/questions/slackware-14/donati... edit: grammar
- smhenderson 7y ago
  Their both on 9.2 in their "current", rolling releases so I guess the race is on!
- asymptotically2 7y ago
  It landed in the Gentoo tree 12 hours ago :D
gilnaa 7y ago
List of bugs fixed in 9.3: https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=9.3 https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED...
- joosters 7y ago
  Are there changelogs for gcc point releases? gcc.gnu.org has a 'changes' link but it is actually a 8->9 changelog, rather than 9.2->9.3
  - not2b 7y ago
    The ChangeLog file is in the source code distribution. But the point releases mainly have a large number of bug fixes, there are no new features.
  - garenp 7y ago
    Yup. If you look at the end of the 'changes' link[1] you'll see individual bugzilla links for issues (or PRs as they call them) that were resolved in a given point release. [1] https://gcc.gnu.org/gcc-9/changes.html https://gcc.gnu.org/gcc-9/changes.html
deleted 7y ago
[deleted]
mratsim 7y ago
I hope one day we will be able to use C to implement efficient multiprecision arithmetic. GCC codegen for add with carry, even with the addcarry_u64 intrinsics is a disgrace[1]. [1]: https://gcc.godbolt.org/z/2h768y https://gcc.godbolt.org/z/2h768y
- BubRoss 7y ago
  Seems like the type of thing that could be done with C++, expression templates and asm. Maybe even an expression JIT.
  - unlinked_dll 7y ago
    Definitely can be done with a little bit of impedance losses depending on what you care about. I once wrote it for block floating point on hardware that didn't support it. You can use custom literal suffixes too.
  - MaxBarraclough 7y ago
    mratsim is right that the solution is to just improve the code-generation for the existing intrinsics. Given that the intrinsics already exist in GCC, optimising the code is the right way to handle it. (Intrinsics still have their usual obvious downsides, mainly non-portability.) JIT seems a poor fit. JIT makes the most sense where the desired program behaviour is variable. Intrinsics fit perfectly here. Templates don't help solve the problem, but they might be a good way to expose the functionality to C++ programmers. Assembly is how you'd solve the problem efficiently in the absence of a compiler intrinsic. Intrinsics should be able to do an even better job.
blackandblue 7y ago
a lot of fortran fixes!
smabie 7y ago
Honest question: what value does GCC have in 2020? It seems like llvm is the better designed compiler, more commercial support, more permissive license, etc. Pretty much everyone designing new languages today is using LLVM for backend codegen; and the people who aren't sure as hell are not using GCC.
- umvi 7y ago
  How's LLVM's code coverage performance? Starting with GCC 9, you can stream gcov straight to stdout in json format, which allowed me to write a multi-core coverage aggregation/analysis tool[1] to replace lcov (and is over 100x faster than lcov, in my case - ymmv): [1] https://github.com/RPGillespie6/fastcov https://github.com/RPGillespie6/fastcov
  - touisteur 7y ago
    Aaaah if only I could do this to a runtime defined fd or pipe... Live coverage information! Have to use Intel PT for this but sometimes feels like a big hammer :-)
- alfalfasprout 7y ago
  It's still the "de facto" compiler on most flavors of Linux and still tends to produce faster binaries in practice than Clang. That gap, however, continues to narrow.
  - CannoloBlahnik 7y ago
    I always viewed Clang as faster, and perceived GCC as catching up.
    - throwaway744678 7y ago
      Clang has faster compilation, but (depending on the actual case) optimized binary built by gcc run faster; as mentioned above, both gaps are narrowing.
    - 7y ago

GCC 9.3

112 points by lelf 7y ago

enriquto 7y ago

I wonder which of my "pet" virtual machines will hit it first: slackware or voidlinux ?

Aaronstotle 7y ago
Out of curiosity, what do you do with either of these "pet" machines? I always have an idea to make a virtual machine cluster, or something similar, but I haven't taken the plunge yet.
- enriquto 7y ago
  I find them very useful for testing codes, as a sort of rapid-response travis. I run a script that pulls any new modification into each of my five "pets" (openbsd, slackware, freebsd, voidlinux+musl, dragonflybsd) and runs the tests. Since the systems are so different, it is very easy to break something. Since you notice it immediately (and not after waiting 1 minute for the travis answer) you develop a sense for avoiding non-portable things.
azinman2 7y ago
Slackware... they still active? No new stable builds in 4 years but seems to get security updates curiously. Their store leads to an error page in what looks like Chinese, confusingly.
- smabie 7y ago
  http://www.slackware.com/changelog/current.php?cpu=x86_64 http://www.slackware.com/changelog/current.php?cpu=x86_64 The changelog seems to be, uhh, changing, so that's good I guess. I'm not sure they have many users left though.
  - smhenderson 7y ago
    We're around and it gained a bit more attention during a recent system wide change to many, more mainstream, distros that I'm sure most people here on HN don't really want to talk about (again). I like it because it leans more closely to traditional BSD systems than System V variants like Red Hat.
- charlesdaniels 7y ago
  Slackware still lives. I'm running it on my daily driver right now. I actually just started using Slackware a few months ago too, so it's gained at least one new user in the last 12 months. Many updates are pushed to https://slackbuilds.org/ https://slackbuilds.org/ every week. Things definitely seem to move slower than on other OSes, but I much prefer it that way. I still run a supported LTS kernel and a supported LTS Firefox release; as long as security updates keep coming I don't feel the need to upgrade to newer software by and large.
- smhenderson 7y ago
  The store thing is a sad state of affairs. Basically, as I understand it, the store was not run by Patrick Volkerding but by a third party that agreed to share profits with him from sales of Slackware branded merchandise. Patrick states that after a few years and much review he was basically being ripped off by them and withdrew permission for them to continue. Although helped by many volunteers Slackware is mostly a one man show and Patrick's income from the project was basically drawing down to zero. It seems to be a long, drawn out affair and I'm trying to come across as neutral here as I'm sure I don't have all the information. But I'll admit some bias as I started my life with Linux using Slackware from a CD that came with a book about Linux, I think in 1994, maybe early 1995. I switched to more mainstream distros at some point based on me using them at various jobs but always liked the idea of Slackware (the most BSD like Linux!). And I'm posting this from a laptop running -current. Yes, 15 has been a long time coming but Patrick continues to publish updates and the Slackware Security mailing list is alive and active. I'm off topic here so I'll wind this up with a note that the GCC package for Slackware Current is gcc-9.2.0-i586-4.txz. So I'm sure 9.3 will be coming along soon, though not as quickly as with some other distros. For those interested in more about the store I found the most relevant information here[1] when I last went looking for a way to contribute money to the project (i.e. to Patrick). [1]https://www.linuxquestions.org/questions/slackware-14/donating-to-slackware-4175634729/ https://www.linuxquestions.org/questions/slackware-14/donati... edit: grammar
smhenderson 7y ago
Their both on 9.2 in their "current", rolling releases so I guess the race is on!
asymptotically2 7y ago
It landed in the Gentoo tree 12 hours ago :D

gilnaa 7y ago

List of bugs fixed in 9.3: https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=9.3 https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED...

joosters 7y ago
Are there changelogs for gcc point releases? gcc.gnu.org has a 'changes' link but it is actually a 8->9 changelog, rather than 9.2->9.3
- not2b 7y ago
  The ChangeLog file is in the source code distribution. But the point releases mainly have a large number of bug fixes, there are no new features.
- garenp 7y ago
  Yup. If you look at the end of the 'changes' link[1] you'll see individual bugzilla links for issues (or PRs as they call them) that were resolved in a given point release. [1] https://gcc.gnu.org/gcc-9/changes.html https://gcc.gnu.org/gcc-9/changes.html

deleted 7y ago

[deleted]

mratsim 7y ago

I hope one day we will be able to use C to implement efficient multiprecision arithmetic. GCC codegen for add with carry, even with the addcarry_u64 intrinsics is a disgrace[1]. [1]: https://gcc.godbolt.org/z/2h768y https://gcc.godbolt.org/z/2h768y

BubRoss 7y ago
Seems like the type of thing that could be done with C++, expression templates and asm. Maybe even an expression JIT.
- unlinked_dll 7y ago
  Definitely can be done with a little bit of impedance losses depending on what you care about. I once wrote it for block floating point on hardware that didn't support it. You can use custom literal suffixes too.
- MaxBarraclough 7y ago
  mratsim is right that the solution is to just improve the code-generation for the existing intrinsics. Given that the intrinsics already exist in GCC, optimising the code is the right way to handle it. (Intrinsics still have their usual obvious downsides, mainly non-portability.) JIT seems a poor fit. JIT makes the most sense where the desired program behaviour is variable. Intrinsics fit perfectly here. Templates don't help solve the problem, but they might be a good way to expose the functionality to C++ programmers. Assembly is how you'd solve the problem efficiently in the absence of a compiler intrinsic. Intrinsics should be able to do an even better job.

blackandblue 7y ago

a lot of fortran fixes!

smabie 7y ago

Honest question: what value does GCC have in 2020? It seems like llvm is the better designed compiler, more commercial support, more permissive license, etc. Pretty much everyone designing new languages today is using LLVM for backend codegen; and the people who aren't sure as hell are not using GCC.

umvi 7y ago
How's LLVM's code coverage performance? Starting with GCC 9, you can stream gcov straight to stdout in json format, which allowed me to write a multi-core coverage aggregation/analysis tool[1] to replace lcov (and is over 100x faster than lcov, in my case - ymmv): [1] https://github.com/RPGillespie6/fastcov https://github.com/RPGillespie6/fastcov
- touisteur 7y ago
  Aaaah if only I could do this to a runtime defined fd or pipe... Live coverage information! Have to use Intel PT for this but sometimes feels like a big hammer :-)
alfalfasprout 7y ago
It's still the "de facto" compiler on most flavors of Linux and still tends to produce faster binaries in practice than Clang. That gap, however, continues to narrow.
- CannoloBlahnik 7y ago
  I always viewed Clang as faster, and perceived GCC as catching up.
  - throwaway744678 7y ago
    Clang has faster compilation, but (depending on the actual case) optimized binary built by gcc run faster; as mentioned above, both gaps are narrowing.
  - 7y ago