* GCC arc port defaults to -fcommon
@ 2021-07-07 8:59 Florian Weimer
2021-07-07 9:56 ` Richard Biener
0 siblings, 1 reply; 6+ messages in thread
From: Florian Weimer @ 2021-07-07 8:59 UTC (permalink / raw)
To: gcc; +Cc: gnu, claziss
It seems to me that the arc port still defaults to -fcommon, presumably
due to this in gcc/common/config/arc/arc-common.c:
static void
arc_option_init_struct (struct gcc_options *opts)
{
opts->x_flag_no_common = 255; /* Mark as not user-initialized. */
/* Which cpu we're compiling for (ARC600, ARC601, ARC700, ARCv2). */
arc_cpu = PROCESSOR_NONE;
}
Is that really necessary? Is -fno-common broken on arc?
I plan to switch glibc to build with -fno-common unconditionally, for
all GCC versions and architectures, and I wonder if that would be a
blocker.
Thanks,
Florian
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: GCC arc port defaults to -fcommon 2021-07-07 8:59 GCC arc port defaults to -fcommon Florian Weimer @ 2021-07-07 9:56 ` Richard Biener 2021-07-07 9:58 ` Richard Biener 0 siblings, 1 reply; 6+ messages in thread From: Richard Biener @ 2021-07-07 9:56 UTC (permalink / raw) To: Florian Weimer Cc: GCC Development, Joern Wolfgang Rennecke, Claudiu Zissulescu On Wed, Jul 7, 2021 at 11:00 AM Florian Weimer via Gcc <gcc@gcc.gnu.org> wrote: > > It seems to me that the arc port still defaults to -fcommon, presumably > due to this in gcc/common/config/arc/arc-common.c: > > static void > arc_option_init_struct (struct gcc_options *opts) > { > opts->x_flag_no_common = 255; /* Mark as not user-initialized. */ > > /* Which cpu we're compiling for (ARC600, ARC601, ARC700, ARCv2). */ > arc_cpu = PROCESSOR_NONE; > } > > Is that really necessary? Is -fno-common broken on arc? It seems arc has -fcommon dependent on !TARGET_NO_SDATA_SET but it should use global_options_set.x_flag_no_common instead of such magic value. > I plan to switch glibc to build with -fno-common unconditionally, for > all GCC versions and architectures, and I wonder if that would be a > blocker. > > Thanks, > Florian > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: GCC arc port defaults to -fcommon 2021-07-07 9:56 ` Richard Biener @ 2021-07-07 9:58 ` Richard Biener 2021-07-07 10:06 ` Florian Weimer 2021-07-07 10:06 ` Claudiu Zissulescu 0 siblings, 2 replies; 6+ messages in thread From: Richard Biener @ 2021-07-07 9:58 UTC (permalink / raw) To: Florian Weimer Cc: GCC Development, Joern Wolfgang Rennecke, Claudiu Zissulescu On Wed, Jul 7, 2021 at 11:56 AM Richard Biener <richard.guenther@gmail.com> wrote: > > On Wed, Jul 7, 2021 at 11:00 AM Florian Weimer via Gcc <gcc@gcc.gnu.org> wrote: > > > > It seems to me that the arc port still defaults to -fcommon, presumably > > due to this in gcc/common/config/arc/arc-common.c: > > > > static void > > arc_option_init_struct (struct gcc_options *opts) > > { > > opts->x_flag_no_common = 255; /* Mark as not user-initialized. */ > > > > /* Which cpu we're compiling for (ARC600, ARC601, ARC700, ARCv2). */ > > arc_cpu = PROCESSOR_NONE; > > } > > > > Is that really necessary? Is -fno-common broken on arc? > > It seems arc has -fcommon dependent on !TARGET_NO_SDATA_SET > but it should use global_options_set.x_flag_no_common instead of > such magic value. So sth like this (untested): diff --git a/gcc/common/config/arc/arc-common.c b/gcc/common/config/arc/arc-common.c index 6a119029616..c8ac7471744 100644 --- a/gcc/common/config/arc/arc-common.c +++ b/gcc/common/config/arc/arc-common.c @@ -32,8 +32,6 @@ along with GCC; see the file COPYING3. If not see static void arc_option_init_struct (struct gcc_options *opts) { - opts->x_flag_no_common = 255; /* Mark as not user-initialized. */ - /* Which cpu we're compiling for (ARC600, ARC601, ARC700, ARCv2). */ arc_cpu = PROCESSOR_NONE; } diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c index 69f6ae464e1..b9097b11835 100644 --- a/gcc/config/arc/arc.c +++ b/gcc/config/arc/arc.c @@ -1440,7 +1440,7 @@ arc_override_options (void) if (flag_pic) target_flags |= MASK_NO_SDATA_SET; - if (flag_no_common == 255) + if (!global_options_set.x_flag_no_common) flag_no_common = !TARGET_NO_SDATA_SET; /* Check for small data option */ > > I plan to switch glibc to build with -fno-common unconditionally, for > > all GCC versions and architectures, and I wonder if that would be a > > blocker. > > > > Thanks, > > Florian > > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: GCC arc port defaults to -fcommon 2021-07-07 9:58 ` Richard Biener @ 2021-07-07 10:06 ` Florian Weimer 2021-07-07 12:18 ` Claudiu Zissulescu 2021-07-07 10:06 ` Claudiu Zissulescu 1 sibling, 1 reply; 6+ messages in thread From: Florian Weimer @ 2021-07-07 10:06 UTC (permalink / raw) To: Richard Biener Cc: GCC Development, Joern Wolfgang Rennecke, Claudiu Zissulescu * Richard Biener: > On Wed, Jul 7, 2021 at 11:56 AM Richard Biener > <richard.guenther@gmail.com> wrote: >> >> On Wed, Jul 7, 2021 at 11:00 AM Florian Weimer via Gcc <gcc@gcc.gnu.org> wrote: >> > >> > It seems to me that the arc port still defaults to -fcommon, presumably >> > due to this in gcc/common/config/arc/arc-common.c: >> > >> > static void >> > arc_option_init_struct (struct gcc_options *opts) >> > { >> > opts->x_flag_no_common = 255; /* Mark as not user-initialized. */ >> > >> > /* Which cpu we're compiling for (ARC600, ARC601, ARC700, ARCv2). */ >> > arc_cpu = PROCESSOR_NONE; >> > } >> > >> > Is that really necessary? Is -fno-common broken on arc? >> >> It seems arc has -fcommon dependent on !TARGET_NO_SDATA_SET >> but it should use global_options_set.x_flag_no_common instead of >> such magic value. > > So sth like this (untested): > > diff --git a/gcc/common/config/arc/arc-common.c > b/gcc/common/config/arc/arc-common.c > index 6a119029616..c8ac7471744 100644 > --- a/gcc/common/config/arc/arc-common.c > +++ b/gcc/common/config/arc/arc-common.c > @@ -32,8 +32,6 @@ along with GCC; see the file COPYING3. If not see > static void > arc_option_init_struct (struct gcc_options *opts) > { > - opts->x_flag_no_common = 255; /* Mark as not user-initialized. */ > - > /* Which cpu we're compiling for (ARC600, ARC601, ARC700, ARCv2). */ > arc_cpu = PROCESSOR_NONE; > } > diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c > index 69f6ae464e1..b9097b11835 100644 > --- a/gcc/config/arc/arc.c > +++ b/gcc/config/arc/arc.c > @@ -1440,7 +1440,7 @@ arc_override_options (void) > if (flag_pic) > target_flags |= MASK_NO_SDATA_SET; > > - if (flag_no_common == 255) > + if (!global_options_set.x_flag_no_common) > flag_no_common = !TARGET_NO_SDATA_SET; > > /* Check for small data option */ But this means that arc still defaults to -fcommon with this change, right? Thanks, Florian ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: GCC arc port defaults to -fcommon 2021-07-07 10:06 ` Florian Weimer @ 2021-07-07 12:18 ` Claudiu Zissulescu 0 siblings, 0 replies; 6+ messages in thread From: Claudiu Zissulescu @ 2021-07-07 12:18 UTC (permalink / raw) To: Florian Weimer, Richard Biener; +Cc: GCC Development, Joern Wolfgang Rennecke Hi, I have quickly tested the next patch, and it looks like everything is alright. In the end we don't really need to temper with fcommon. diff --git a/gcc/common/config/arc/arc-common.c b/gcc/common/config/arc/arc-common.c index 6a1190296167..3b36d09997c7 100644 --- a/gcc/common/config/arc/arc-common.c +++ b/gcc/common/config/arc/arc-common.c @@ -30,10 +30,8 @@ along with GCC; see the file COPYING3. If not see #include "flags.h" static void -arc_option_init_struct (struct gcc_options *opts) +arc_option_init_struct (struct gcc_options *opts ATTRIBUTE_UNUSED) { - opts->x_flag_no_common = 255; /* Mark as not user-initialized. */ - /* Which cpu we're compiling for (ARC600, ARC601, ARC700, ARCv2). */ arc_cpu = PROCESSOR_NONE; } diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c index 584783f2fb88..5f1d2ffd3995 100644 --- a/gcc/config/arc/arc.c +++ b/gcc/config/arc/arc.c @@ -1449,9 +1449,6 @@ arc_override_options (void) target_flags |= MASK_NO_SDATA_SET; } - if (flag_no_common == 255) - flag_no_common = !TARGET_NO_SDATA_SET; - /* Check for small data option */ if (!global_options_set.x_g_switch_value && !TARGET_NO_SDATA_SET) g_switch_value = TARGET_LL64 ? 8 : 4; ________________________________ From: Florian Weimer <fweimer@redhat.com> Sent: Wednesday, July 7, 2021 1:06 PM To: Richard Biener <richard.guenther@gmail.com> Cc: GCC Development <gcc@gcc.gnu.org>; Joern Wolfgang Rennecke <gnu@amylaar.uk>; Claudiu Zissulescu <claziss@synopsys.com> Subject: Re: GCC arc port defaults to -fcommon * Richard Biener: > On Wed, Jul 7, 2021 at 11:56 AM Richard Biener > <richard.guenther@gmail.com> wrote: >> >> On Wed, Jul 7, 2021 at 11:00 AM Florian Weimer via Gcc <gcc@gcc.gnu.org> wrote: >> > >> > It seems to me that the arc port still defaults to -fcommon, presumably >> > due to this in gcc/common/config/arc/arc-common.c: >> > >> > static void >> > arc_option_init_struct (struct gcc_options *opts) >> > { >> > opts->x_flag_no_common = 255; /* Mark as not user-initialized. */ >> > >> > /* Which cpu we're compiling for (ARC600, ARC601, ARC700, ARCv2). */ >> > arc_cpu = PROCESSOR_NONE; >> > } >> > >> > Is that really necessary? Is -fno-common broken on arc? >> >> It seems arc has -fcommon dependent on !TARGET_NO_SDATA_SET >> but it should use global_options_set.x_flag_no_common instead of >> such magic value. > > So sth like this (untested): > > diff --git a/gcc/common/config/arc/arc-common.c > b/gcc/common/config/arc/arc-common.c > index 6a119029616..c8ac7471744 100644 > --- a/gcc/common/config/arc/arc-common.c > +++ b/gcc/common/config/arc/arc-common.c > @@ -32,8 +32,6 @@ along with GCC; see the file COPYING3. If not see > static void > arc_option_init_struct (struct gcc_options *opts) > { > - opts->x_flag_no_common = 255; /* Mark as not user-initialized. */ > - > /* Which cpu we're compiling for (ARC600, ARC601, ARC700, ARCv2). */ > arc_cpu = PROCESSOR_NONE; > } > diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c > index 69f6ae464e1..b9097b11835 100644 > --- a/gcc/config/arc/arc.c > +++ b/gcc/config/arc/arc.c > @@ -1440,7 +1440,7 @@ arc_override_options (void) > if (flag_pic) > target_flags |= MASK_NO_SDATA_SET; > > - if (flag_no_common == 255) > + if (!global_options_set.x_flag_no_common) > flag_no_common = !TARGET_NO_SDATA_SET; > > /* Check for small data option */ But this means that arc still defaults to -fcommon with this change, right? Thanks, Florian ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: GCC arc port defaults to -fcommon 2021-07-07 9:58 ` Richard Biener 2021-07-07 10:06 ` Florian Weimer @ 2021-07-07 10:06 ` Claudiu Zissulescu 1 sibling, 0 replies; 6+ messages in thread From: Claudiu Zissulescu @ 2021-07-07 10:06 UTC (permalink / raw) To: Richard Biener, Florian Weimer; +Cc: GCC Development, Joern Wolfgang Rennecke The fno-common option is indeed related to the use of small-data. However, the small data is only used for baremetal applications, and it shouldn't be used for linux toolchain. To me Richard's patch looks alright. Thanks, Claudiu ________________________________ From: Richard Biener <richard.guenther@gmail.com> Sent: Wednesday, July 7, 2021 12:58 PM To: Florian Weimer <fweimer@redhat.com> Cc: GCC Development <gcc@gcc.gnu.org>; Joern Wolfgang Rennecke <gnu@amylaar.uk>; Claudiu Zissulescu <claziss@synopsys.com> Subject: Re: GCC arc port defaults to -fcommon On Wed, Jul 7, 2021 at 11:56 AM Richard Biener <richard.guenther@gmail.com> wrote: > > On Wed, Jul 7, 2021 at 11:00 AM Florian Weimer via Gcc <gcc@gcc.gnu.org> wrote: > > > > It seems to me that the arc port still defaults to -fcommon, presumably > > due to this in gcc/common/config/arc/arc-common.c: > > > > static void > > arc_option_init_struct (struct gcc_options *opts) > > { > > opts->x_flag_no_common = 255; /* Mark as not user-initialized. */ > > > > /* Which cpu we're compiling for (ARC600, ARC601, ARC700, ARCv2). */ > > arc_cpu = PROCESSOR_NONE; > > } > > > > Is that really necessary? Is -fno-common broken on arc? > > It seems arc has -fcommon dependent on !TARGET_NO_SDATA_SET > but it should use global_options_set.x_flag_no_common instead of > such magic value. So sth like this (untested): diff --git a/gcc/common/config/arc/arc-common.c b/gcc/common/config/arc/arc-common.c index 6a119029616..c8ac7471744 100644 --- a/gcc/common/config/arc/arc-common.c +++ b/gcc/common/config/arc/arc-common.c @@ -32,8 +32,6 @@ along with GCC; see the file COPYING3. If not see static void arc_option_init_struct (struct gcc_options *opts) { - opts->x_flag_no_common = 255; /* Mark as not user-initialized. */ - /* Which cpu we're compiling for (ARC600, ARC601, ARC700, ARCv2). */ arc_cpu = PROCESSOR_NONE; } diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c index 69f6ae464e1..b9097b11835 100644 --- a/gcc/config/arc/arc.c +++ b/gcc/config/arc/arc.c @@ -1440,7 +1440,7 @@ arc_override_options (void) if (flag_pic) target_flags |= MASK_NO_SDATA_SET; - if (flag_no_common == 255) + if (!global_options_set.x_flag_no_common) flag_no_common = !TARGET_NO_SDATA_SET; /* Check for small data option */ > > I plan to switch glibc to build with -fno-common unconditionally, for > > all GCC versions and architectures, and I wonder if that would be a > > blocker. > > > > Thanks, > > Florian > > ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-07-07 12:19 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-07-07 8:59 GCC arc port defaults to -fcommon Florian Weimer 2021-07-07 9:56 ` Richard Biener 2021-07-07 9:58 ` Richard Biener 2021-07-07 10:06 ` Florian Weimer 2021-07-07 12:18 ` Claudiu Zissulescu 2021-07-07 10:06 ` Claudiu Zissulescu
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