@@ -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
@@ -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 happends 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(+)