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authorZack Weinberg <zackw@panix.com>2018-03-07 14:31:57 -0500
committerGabriel F. T. Gomes <gabriel@inconstante.eti.br>2018-11-16 09:21:14 -0200
commitc75772e3f079b9265738e2f54644ee47f932d99a (patch)
treef779b4f7b6e2de6eb5dbcf367824c71419d046fb /stdlib
parent346ef23f197a0c8ba807c344bd39101b711050ee (diff)
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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 'stdlib')
-rw-r--r--stdlib/strfmon.c3
-rw-r--r--stdlib/strfmon_l.c8
2 files changed, 6 insertions, 5 deletions
diff --git a/stdlib/strfmon.c b/stdlib/strfmon.c
index 01980d3..3058b3e 100644
--- a/stdlib/strfmon.c
+++ b/stdlib/strfmon.c
@@ -30,7 +30,8 @@ __strfmon (char *s, size_t maxsize, const char *format, ...)
va_start (ap, format);
- ssize_t res = __vstrfmon_l (s, maxsize, _NL_CURRENT_LOCALE, format, ap);
+ ssize_t res = __vstrfmon_l_internal (s, maxsize, _NL_CURRENT_LOCALE,
+ format, ap, 0);
va_end (ap);
diff --git a/stdlib/strfmon_l.c b/stdlib/strfmon_l.c
index cd3796c..5293104 100644
--- a/stdlib/strfmon_l.c
+++ b/stdlib/strfmon_l.c
@@ -76,8 +76,8 @@
too. Some of the information contradicts the information which can
be specified in format string. */
ssize_t
-__vstrfmon_l (char *s, size_t maxsize, locale_t loc, const char *format,
- va_list ap)
+__vstrfmon_l_internal (char *s, size_t maxsize, locale_t loc,
+ const char *format, va_list ap, unsigned int flags)
{
struct __locale_data *current = loc->__locales[LC_MONETARY];
_IO_strfile f;
@@ -268,7 +268,7 @@ __vstrfmon_l (char *s, size_t maxsize, locale_t loc, const char *format,
if (*fmt == 'L')
{
++fmt;
- if (!__ldbl_is_dbl)
+ if (__glibc_likely ((flags & STRFMON_LDBL_IS_DBL) == 0))
is_long_double = 1;
}
@@ -608,7 +608,7 @@ ___strfmon_l (char *s, size_t maxsize, locale_t loc, const char *format, ...)
va_start (ap, format);
- ssize_t res = __vstrfmon_l (s, maxsize, loc, format, ap);
+ ssize_t res = __vstrfmon_l_internal (s, maxsize, loc, format, ap, 0);
va_end (ap);