Re: [PATCH] PR85678: Change default to -fno-common

2019-12-05 Thread Jeff Law
On 12/5/19 6:18 AM, Wilco Dijkstra wrote: > Hi, > > I have updated the documentation patch here and added relevant maintainers > so hopefully this can go in soon: > https://gcc.gnu.org/ml/gcc-patches/2019-12/msg00311.html > > I moved the paragraph in changes.html to the C section like you

Re: [PATCH] PR85678: Change default to -fno-common

2019-12-05 Thread Jeff Law
On 12/5/19 2:16 AM, Martin Liška wrote: > >> >> Of the ~450 packages affected I'd estimate that even with the opt-out >> mechanism we're still going to have to fix ~100 packages immediately >> because they don't honor the flags injection mechanisms which the >> opt-out approach relies upon. > >

Re: [PATCH] PR85678: Change default to -fno-common

2019-12-05 Thread Wilco Dijkstra
Hi, I have updated the documentation patch here and added relevant maintainers so hopefully this can go in soon: https://gcc.gnu.org/ml/gcc-patches/2019-12/msg00311.html I moved the paragraph in changes.html to the C section like you suggested. Would it make sense to link to the porting_to

Re: [PATCH] PR85678: Change default to -fno-common

2019-12-05 Thread Tobias Burnus
On 12/5/19 10:16 AM, Martin Liška wrote: I would like to mention here that key work is to report and explain that to upstream. Only that will help for the future to reduce number of packages that will need the -fcommon option. That's the biggest effort in my opinion. For this, it would help

Re: [PATCH] PR85678: Change default to -fno-common

2019-12-05 Thread Martin Liška
On 12/4/19 6:27 PM, Jeff Law wrote: On 12/4/19 8:24 AM, Wilco Dijkstra wrote: Hi Jeff, I've noticed quite significant package failures caused by the revision. Would you please consider documenting this change in porting_to.html (and in changes.html) for GCC 10 release? I'm not in the office

Re: [PATCH] PR85678: Change default to -fno-common

2019-12-04 Thread Jeff Law
On 12/4/19 2:03 PM, Joseph Myers wrote: > On Wed, 4 Dec 2019, Jeff Law wrote: > >>> So what normally happens with the numerous new warnings/errors in GCC >>> releases? I suppose that could cause package failures too. Would it be >>> feasible >>> to override the options for any failing packages?

Re: [PATCH] PR85678: Change default to -fno-common

2019-12-04 Thread Joseph Myers
On Wed, 4 Dec 2019, Jeff Law wrote: > > So what normally happens with the numerous new warnings/errors in GCC > > releases? I suppose that could cause package failures too. Would it be > > feasible > > to override the options for any failing packages? > Usually we're talking about a few dozen

Re: [PATCH] PR85678: Change default to -fno-common

2019-12-04 Thread Jeff Law
On 12/4/19 8:24 AM, Wilco Dijkstra wrote: > Hi Jeff, > >>> I've noticed quite significant package failures caused by the revision. >>> Would you please consider documenting this change in porting_to.html >>> (and in changes.html) for GCC 10 release? >> >> I'm not in the office right now, but

Re: [PATCH] PR85678: Change default to -fno-common

2019-12-04 Thread Wilco Dijkstra
Hi Jeff, >> I've noticed quite significant package failures caused by the revision. >> Would you please consider documenting this change in porting_to.html >> (and in changes.html) for GCC 10 release? > > I'm not in the office right now, but figured I'd chime in.  I'd estimate > 400-500 packages

Re: [PATCH] PR85678: Change default to -fno-common (porting_to for GCC 10)

2019-11-30 Thread Eric Gallager
On 11/29/19, Wilco Dijkstra wrote: > Hi Martin, > >> I've noticed quite significant package failures caused by the revision. > > How significant? Is it mostly the common mistake of forgetting extern? > >> Would you please consider documenting this change in porting_to.html >> (and in

Re: [PATCH] PR85678: Change default to -fno-common

2019-11-29 Thread Martin Liška
On 11/29/19 3:43 PM, Wilco Dijkstra wrote: How significant? Is it mostly the common mistake of forgetting extern? Likely, I see it in at least 400 packages out of 11000 which we have in openSUSE:Factory. Plus there are many 'nm -B' configure script defects:

Re: [PATCH] PR85678: Change default to -fno-common

2019-11-29 Thread Wilco Dijkstra
Hi Martin, > I've noticed quite significant package failures caused by the revision. How significant? Is it mostly the common mistake of forgetting extern? > Would you please consider documenting this change in porting_to.html > (and in changes.html) for GCC 10 release? Sure, I already had a

Re: [PATCH] PR85678: Change default to -fno-common

2019-11-29 Thread Martin Liška
Hello. I've noticed quite significant package failures caused by the revision. Would you please consider documenting this change in porting_to.html (and in changes.html) for GCC 10 release? Thank you

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-29 Thread Iain Sandoe
Hi Wilco, Wilco Dijkstra wrote: >> Testsuite fails are order “a few hundred” mostly seem to be related to >> tree-prof >> and vector tests (plus the anticipated scan-asm stuff, where code-gen will >> have >> changed). I don’t have cycles to analyse the causes right now - but that >> gives

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-29 Thread Wilco Dijkstra
Hi Iain, > for the record,  Darwin bootstraps OK with the change (which is to be > expected, > since the preferred setting for it is -fno-common). That's good to hear. > Testsuite fails are order “a few hundred” mostly seem to be related to > tree-prof > and vector tests (plus the anticipated

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-29 Thread Richard Biener
On Mon, Oct 28, 2019 at 10:39 PM Iain Sandoe wrote: > > Wilco Dijkstra wrote: > >>> > >>> I suppose targets can override this decision. > >> I think they probably could via the override_options mechanism. > > > > Yes, it's trivial to add this to target_option_override(): > > > > if

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-28 Thread Iain Sandoe
Wilco Dijkstra wrote: >>> >>> I suppose targets can override this decision. >> I think they probably could via the override_options mechanism. > > Yes, it's trivial to add this to target_option_override(): > > if (!global_options_set.x_flag_no_common) >flag_no_common = 0; for the

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-28 Thread Wilco Dijkstra
Hi, >> I suppose targets can override this decision. > I think they probably could via the override_options mechanism. Yes, it's trivial to add this to target_option_override(): if (!global_options_set.x_flag_no_common) flag_no_common = 0; Cheers, Wilco

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-28 Thread Jeff Law
On 10/28/19 1:43 PM, Richard Biener wrote: > On October 28, 2019 7:43:33 PM GMT+01:00, David Edelsohn > wrote: Has this been bootstrapped and regression tested? >>> >>> Yes, it bootstraps OK of course. I ran regression over the weekend, >> there >>> are a few minor regressions in lto due to

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-28 Thread Richard Biener
On October 28, 2019 7:43:33 PM GMT+01:00, David Edelsohn wrote: >>> Has this been bootstrapped and regression tested? >> >> Yes, it bootstraps OK of course. I ran regression over the weekend, >there >> are a few minor regressions in lto due to relying on tentative >definitions >> and a few

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-28 Thread David Edelsohn
>> Has this been bootstrapped and regression tested? > > Yes, it bootstraps OK of course. I ran regression over the weekend, there > are a few minor regressions in lto due to relying on tentative definitions > and a few latent bugs. I'd expect there will be a few similar failures on > other

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-28 Thread Segher Boessenkool
On Mon, Oct 28, 2019 at 03:05:58PM +, Wilco Dijkstra wrote: > > Has this been bootstrapped and regression tested? > > Yes, it bootstraps OK of course. I ran regression over the weekend, there > are a few minor regressions in lto due to relying on tentative definitions > and a few latent bugs.

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-28 Thread Wilco Dijkstra
Hi Jeff, > Has this been bootstrapped and regression tested? Yes, it bootstraps OK of course. I ran regression over the weekend, there are a few minor regressions in lto due to relying on tentative definitions and a few latent bugs. I'd expect there will be a few similar failures on other

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-26 Thread Harald van Dijk
On 25/10/2019 16:47, Wilco Dijkstra wrote: GCC currently defaults to -fcommon. As discussed in the PR, this is an ancient C feature which is not conforming with the latest C standards. The PR references C99/C11 6.9p5, but that is not a constraint. Any violation merely renders the behaviour

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-26 Thread Jeff Law
On 10/25/19 9:47 AM, Wilco Dijkstra wrote: > GCC currently defaults to -fcommon. As discussed in the PR, this is an > ancient > C feature which is not conforming with the latest C standards. On many > targets > this means global variable accesses have a codesize and performance penalty. > This

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-26 Thread Segher Boessenkool
On Sat, Oct 26, 2019 at 12:21:15PM +0100, Iain Sandoe wrote: > Georg-Johann Lay wrote: > > Wilco Dijkstra schrieb: > >> GCC currently defaults to -fcommon. As discussed in the PR, this is an > >> ancient > >> C feature which is not conforming with the latest C standards. On many > >> targets

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-26 Thread Iain Sandoe
Georg-Johann Lay wrote: > Wilco Dijkstra schrieb: >> GCC currently defaults to -fcommon. As discussed in the PR, this is an >> ancient >> C feature which is not conforming with the latest C standards. On many >> targets >> this means global variable accesses have a codesize and performance

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-25 Thread Segher Boessenkool
On Fri, Oct 25, 2019 at 03:47:10PM +, Wilco Dijkstra wrote: > GCC currently defaults to -fcommon. As discussed in the PR, this is an > ancient > C feature which is not conforming with the latest C standards. On many > targets > this means global variable accesses have a codesize and

Re: [PATCH] PR85678: Change default to -fno-common

2019-10-25 Thread Georg-Johann Lay
Wilco Dijkstra schrieb: GCC currently defaults to -fcommon. As discussed in the PR, this is an ancient C feature which is not conforming with the latest C standards. On many targets this means global variable accesses have a codesize and performance penalty. This applies to C code only, C++

[PATCH] PR85678: Change default to -fno-common

2019-10-25 Thread Wilco Dijkstra
GCC currently defaults to -fcommon. As discussed in the PR, this is an ancient C feature which is not conforming with the latest C standards. On many targets this means global variable accesses have a codesize and performance penalty. This applies to C code only, C++ code is not affected by