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sysdeps/ieee754/soft-fp: ignore maybe-uninitialized with -O [BZ #19444]

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* 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.

	[BZ #19444]
	* sysdeps/ieee754/soft-fp/s_fdiv.c: Include <libc-diag.h> and use
	DIAG_PUSH_NEEDS_COMMENT, DIAG_IGNORE_NEEDS_COMMENT and
	DIAG_POP_NEEDS_COMMENT to disable -Wmaybe-uninitialized.
This commit is contained in:
Martin Jansa
2018-10-02 15:38:43 +00:00
committed by Joseph Myers
parent a06fc4a533
commit 4a06ceea33
2 changed files with 19 additions and 0 deletions
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7
ChangeLog
View File

@@ -1,3 +1,10 @@
2018-10-02 Martin Jansa <Martin.Jansa@gmail.com>
[BZ #19444]
* sysdeps/ieee754/soft-fp/s_fdiv.c: Include <libc-diag.h> and use
DIAG_PUSH_NEEDS_COMMENT, DIAG_IGNORE_NEEDS_COMMENT and
DIAG_POP_NEEDS_COMMENT to disable -Wmaybe-uninitialized.
2018-10-02 Adhemerval Zanella <adhemerval.zanella@linaro.org> 2018-10-02 Adhemerval Zanella <adhemerval.zanella@linaro.org>
* sysdeps/unix/sysv/linux/fd_to_filename.h: Add missing includes. * sysdeps/unix/sysv/linux/fd_to_filename.h: Add missing includes.

12
sysdeps/ieee754/soft-fp/s_fdiv.c
View File

@@ -25,6 +25,16 @@
#undef fdivl #undef fdivl
#include <math-narrow.h> #include <math-narrow.h>
#include <libc-diag.h>
/* R_f[01] are not set in cases where they are not used in packing,
but the compiler does not see that they are set in all cases where
they are used, resulting in warnings that they 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 <soft-fp.h>
#include <single.h> #include <single.h>
#include <double.h> #include <double.h>
@@ -53,4 +63,6 @@ __fdiv (double x, double y)
CHECK_NARROW_DIV (ret, x, y); CHECK_NARROW_DIV (ret, x, y);
return ret; return ret;
} }
DIAG_POP_NEEDS_COMMENT;
libm_alias_float_double (div) libm_alias_float_double (div)