GCC 5.2 released • Hacker News Board

Re: GCC 5.2 released

#21

Post by sajal83 » Thu, Jul 16, 2015, 4:02 PM UTC

ademarre wrote: post #17

With this release the golang frontend catches up it'so Go version 1.4.2. EDIT: I'm wrong. That was GCC 5.1.

Nopes. Go 1.4.2 was released with GCC 5.1 (April 22, 2015). This release is just bugfixes.

Re: GCC 5.2 released

#22

Post by bsdetector » Thu, Jul 16, 2015, 4:43 PM UTC

ademarre wrote: post #17

With this release the golang frontend catches up it'so Go version 1.4.2. EDIT: I'm wrong. That was GCC 5.1.

I'm more interested in why GCC still doesn't have a D frontend.

Back when people were criticizing Google for acquiring GCC developers and then adding their own Go language I think they promised to add D in like 4.6 or something like that.

Re: GCC 5.2 released

#23

Post by greglindahl » Thu, Jul 16, 2015, 4:46 PM UTC

spacehome wrote: post #19

the8472 wrote: post #7

> Write-only variables are now detected and optimized out. That's probably something one should keep in mind when writing micro-benchmarks.

I'm appalled that this wasn't taken care of 20 years ago. It seems like such low-hanging fruit.

This is a standard compiler feature, yes -- lots of real code out there has a lot of dead writes, such as debugging code that has been only partly removed or disabled. Historically, it's been a significant win for some of the SPECcpu benchmarks.

Re: GCC 5.2 released

#24

Post by ademarre » Thu, Jul 16, 2015, 5:05 PM UTC

sajal83 wrote: post #21

ademarre wrote: post #17

With this release the golang frontend catches up it'so Go version 1.4.2. EDIT: I'm wrong. That was GCC 5.1.

Nopes. Go 1.4.2 was released with GCC 5.1 (April 22, 2015). This release is just bugfixes.

Thanks; you're right. I read the 5 series general release notes as if it were for 5.2.

Re: GCC 5.2 released

#25

Post by rst » Thu, Jul 16, 2015, 5:19 PM UTC

agwa wrote: post #14

It's worth noting that, due to GCC's new and esoteric version numbering scheme[1], this is a bugfix-only release on the 5.x branch. The bigger news was when GCC 5.1 (a major stable release) was released in April. That said, GCC 5.2 fixes a pretty serious bug that I was hitting so I'm happy to hear about it! [1] https://gcc.gnu.org/develop.html#num_scheme

They switched the default C compilation mode from --std=gnu89 to --std=gnu11 in a bugfix-only release?

Re: GCC 5.2 released

#26

Post by agwa » Thu, Jul 16, 2015, 5:24 PM UTC

rst wrote: post #25

agwa wrote: post #14

It's worth noting that, due to GCC's new and esoteric version numbering scheme[1], this is a bugfix-only release on the 5.x branch. The bigger news was when GCC 5.1 (a major stable release) was released in April. That said, GCC 5.2 fixes a pretty serious bug that I was hitting so I'm happy to hear about it! [1] https://gcc.gnu.org/develop.html#num_scheme

They switched the default C compilation mode from --std=gnu89 to --std=gnu11 in a bugfix-only release?

No, they did that in 5.1. The linked page is mostly about the overall 5.x series, with a tiny little section at the bottom about 5.2.

Re: GCC 5.2 released

#27

Post by gtk40 » Thu, Jul 16, 2015, 5:50 PM UTC

joosters wrote: post #10

tosseraccount wrote: post #4

Any benchmarks? How does this compare with previous versions of gcc?

The release notes mention several benchmark comparisons.

I don't see any benchmarks showing improvements in 5.2. The 5.2 information seems sparse. Could you point this out?

Re: GCC 5.2 released

#28

Post by JoshTriplett » Thu, Jul 16, 2015, 5:52 PM UTC

nitrogen wrote: post #9

the8472 wrote: post #7

> Write-only variables are now detected and optimized out. That's probably something one should keep in mind when writing micro-benchmarks.

There should be a warning for this enabled in every C project.

GCC has a warning for that, and yes, it should be.

Re: GCC 5.2 released

#29

Post by 3JPLW » Thu, Jul 16, 2015, 5:53 PM UTC

agwa wrote: post #14

It's worth noting that, due to GCC's new and esoteric version numbering scheme[1], this is a bugfix-only release on the 5.x branch. The bigger news was when GCC 5.1 (a major stable release) was released in April. That said, GCC 5.2 fixes a pretty serious bug that I was hitting so I'm happy to hear about it! [1] https://gcc.gnu.org/develop.html#num_scheme

Woah, new and esoteric indeed!

    X.0.0 is experimental development
    X.0.1 is pre-release stabilization stage
    X.1.0 is the stable release
    X.1.1 is development of release branch (fixes and backports)
    X.2.0 is the second stable release

It looks like only X.1.0, X.2.0, etc uniquely tag a single point in the development history. Are all the others just moving labels?

Re: GCC 5.2 released

#30

Post by jlarocco » Thu, Jul 16, 2015, 6:07 PM UTC

bsdetector wrote: post #22

ademarre wrote: post #17

With this release the golang frontend catches up it'so Go version 1.4.2. EDIT: I'm wrong. That was GCC 5.1.

I'm more interested in why GCC still doesn't have a D frontend. Back when people were criticizing Google for acquiring GCC developers and then adding their own Go language I think they promised to add D in like 4.6 or something like that.

I don't know anything about that, but there's already a D front end for GCC: http://gdcproject.org