Message ID | 20181001162622.31039-1-Martin.Jansa@gmail.com |
---|---|
State | New |
Headers | show |
Series | [PATCHv4] sysdeps/ieee754/soft-fp: ignore maybe-uninitialized with -O [BZ #19444] | expand |
Thanks, committed.
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
On 03/01/2019 12:44, Mark Corbin wrote: > > > 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 > Done.
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)
* with -O, -O1, -Os it fails with: In file included from ../soft-fp/soft-fp.h:318, from ../sysdeps/ieee754/soft-fp/s_fdiv.c:28: ../sysdeps/ieee754/soft-fp/s_fdiv.c: In function '__fdiv': ../soft-fp/op-2.h:98:25: error: 'R_f1' may be used uninitialized in this function [-Werror=maybe-uninitialized] X##_f0 = (X##_f1 << (_FP_W_TYPE_SIZE - (N)) | X##_f0 >> (N) \ ^~ ../sysdeps/ieee754/soft-fp/s_fdiv.c:38:14: note: 'R_f1' was declared here FP_DECL_D (R); ^ ../soft-fp/op-2.h:37:36: note: in definition of macro '_FP_FRAC_DECL_2' _FP_W_TYPE X##_f0 _FP_ZERO_INIT, X##_f1 _FP_ZERO_INIT ^ ../soft-fp/double.h:95:24: note: in expansion of macro '_FP_DECL' # define FP_DECL_D(X) _FP_DECL (2, X) ^~~~~~~~ ../sysdeps/ieee754/soft-fp/s_fdiv.c:38:3: note: in expansion of macro 'FP_DECL_D' FP_DECL_D (R); ^~~~~~~~~ ../soft-fp/op-2.h:101:17: error: 'R_f0' may be used uninitialized in this function [-Werror=maybe-uninitialized] : (X##_f0 << (_FP_W_TYPE_SIZE - (N))) != 0)); \ ^~ ../sysdeps/ieee754/soft-fp/s_fdiv.c:38:14: note: 'R_f0' was declared here FP_DECL_D (R); ^ ../soft-fp/op-2.h:37:14: note: in definition of macro '_FP_FRAC_DECL_2' _FP_W_TYPE X##_f0 _FP_ZERO_INIT, X##_f1 _FP_ZERO_INIT ^ ../soft-fp/double.h:95:24: note: in expansion of macro '_FP_DECL' # define FP_DECL_D(X) _FP_DECL (2, X) ^~~~~~~~ ../sysdeps/ieee754/soft-fp/s_fdiv.c:38:3: note: in expansion of macro 'FP_DECL_D' FP_DECL_D (R); ^~~~~~~~~ Build tested with Yocto for ARM, AARCH64, X86, X86_64, PPC, MIPS, MIPS64 with -O, -O1, -Os. For AARCH64 it needs one more fix in locale for -Os. Partial fix for [BZ #23716] * sysdeps/ieee754/soft-fp/s_fdiv.c: Fix build with -O Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com> --- ChangeLog | 4 ++++ sysdeps/ieee754/soft-fp/s_fdiv.c | 12 ++++++++++++ 2 files changed, 16 insertions(+)