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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 /include
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 'include')
-rw-r--r--include/monetary.h17
1 files changed, 14 insertions, 3 deletions
diff --git a/include/monetary.h b/include/monetary.h
index c130ed5..f59bdf9 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