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| author | Zack Weinberg <zackw@panix.com> | 2018-03-07 14:31:57 -0500 |
|---|---|---|
| committer | Gabriel F. T. Gomes <gabriel@inconstante.eti.br> | 2018-11-16 09:21:14 -0200 |
| commit | c75772e3f079b9265738e2f54644ee47f932d99a (patch) | |
| tree | f779b4f7b6e2de6eb5dbcf367824c71419d046fb /include | |
| parent | 346ef23f197a0c8ba807c344bd39101b711050ee (diff) | |
| download | glibc-c75772e3f079b9265738e2f54644ee47f932d99a.tar.gz | |
Use STRFMON_LDBL_IS_DBL instead of __ldbl_is_dbl.
On platforms where long double used to have the same format as double,
but later switched to a different format (alpha, s390, sparc, and
powerpc), accessing the older behavior is possible and it happens via
__nldbl_* functions (not on the API, but accessible from header
redirection and from compat symbols). These functions write to the
global flag __ldbl_is_dbl, which tells other functions that long double
variables should be handled as double. This patch takes the first step
towards removing this global flag and creates __vstrfmon_l_internal,
which takes an explicit flags parameter.
This change arguably makes the generated code slightly worse on
architectures where __ldbl_is_dbl is never true; right now, on those
architectures, it's a compile-time constant; after this change, the
compiler could theoretically prove that __vstrfmon_l_internal was
never called with a nonzero flags argument, but it would probably need
LTO to do it. This is not performance critical code and I tend to
think that the maintainability benefits of removing action at a
distance are worth it. However, we _could_ wrap the runtime flag
check with a macro that was defined to ignore its argument and always
return false on architectures where __ldbl_is_dbl is never true, if
people think the codegen benefits are important.
Tested for powerpc and powerpc64le.
Diffstat (limited to 'include')
| -rw-r--r-- | include/monetary.h | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/include/monetary.h b/include/monetary.h index c130ed56a3..f59bdf9150 100644 --- a/include/monetary.h +++ b/include/monetary.h @@ -2,7 +2,18 @@ #ifndef _ISOMAC #include <stdarg.h> -extern ssize_t __vstrfmon_l (char *s, size_t maxsize, locale_t loc, - const char *format, va_list ap) - attribute_hidden; +extern ssize_t +__vstrfmon_l_internal (char *s, size_t maxsize, locale_t loc, + const char *format, va_list ap, + unsigned int flags) + attribute_hidden; + +/* Flags for __vstrfmon_l_internal. + + STRFMON_LDBL_IS_DBL is a one-bit mask for the flags parameter that + indicates whether long double values are to be handled as having the + same format as double, in which case the flag should be set to one, + or as another format, otherwise. */ +#define STRFMON_LDBL_IS_DBL 0x0001 + #endif |