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Re: [PATCHv4] sysdeps/ieee754/soft-fp: ignore maybe-uninitialized with -O [BZ #19444]
- From: Mark Corbin <mark dot corbin at embecosm dot com>
- To: Martin Jansa <martin dot jansa at gmail dot com>, libc-alpha at sourceware dot org
- Date: Thu, 3 Jan 2019 14:44:21 +0000
- Subject: Re: [PATCHv4] sysdeps/ieee754/soft-fp: ignore maybe-uninitialized with -O [BZ #19444]
- References: <20181001162622.31039-1-Martin.Jansa@gmail.com>
- Reply-to: mark dot corbin at embecosm dot com
On 01/10/2018 17:26, Martin Jansa wrote:
> ---
> ChangeLog | 4 ++++
> sysdeps/ieee754/soft-fp/s_fdiv.c | 12 ++++++++++++
> 2 files changed, 16 insertions(+)
>
> diff --git a/ChangeLog b/ChangeLog
> index 4bafeefda5..9cdf59c9ab 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -1,3 +1,7 @@
> +2018-09-30 Martin Jansa <Martin.Jansa@gmail.com>
> + Partial fix for [BZ #23716]
> + * sysdeps/ieee754/soft-fp/s_fdiv.c: Fix build with -O.
> +
> 2018-09-29 Martin Jansa <Martin.Jansa@gmail.com>
> Partial fix for [BZ #23716]
> * sysdeps/ieee754/dbl-96/e_jnl.c: Fix build with -O
> diff --git a/sysdeps/ieee754/soft-fp/s_fdiv.c b/sysdeps/ieee754/soft-fp/s_fdiv.c
> index 341339f5ed..f124edd760 100644
> --- a/sysdeps/ieee754/soft-fp/s_fdiv.c
> +++ b/sysdeps/ieee754/soft-fp/s_fdiv.c
> @@ -25,6 +25,16 @@
> #undef fdivl
>
> #include <math-narrow.h>
> +
> +#include <libc-diag.h>
> +/* R_f[01] are not set in cases where it is not used in packing, but the
> + compiler does not see that it is set in all cases where it is
> + used, resulting in warnings that it may be used uninitialized.
> + The location of the warning differs in different versions of GCC,
> + it may be where R is defined using a macro or it may be where the
> + macro is defined. This happens only with -O1. */
> +DIAG_PUSH_NEEDS_COMMENT;
> +DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized");
> #include <soft-fp.h>
> #include <single.h>
> #include <double.h>
> @@ -53,4 +63,6 @@ __fdiv (double x, double y)
> CHECK_NARROW_DIV (ret, x, y);
> return ret;
> }
> +DIAG_POP_NEEDS_COMMENT;
> +
> libm_alias_float_double (div)
Hello
It would be really helpful if this fix (commit id
4a06ceea33ecc220bbfe264d8f1e74de2f04e90d) could be backported from
master to the release/2.28/master branch.
This would allow all glibc 2.28 patches to be dropped from Buildroot.
Thanks
Mark
--
Mark Corbin
Embecosm Ltd.
https://www.embecosm.com