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Diffstat (limited to '')
| -rw-r--r-- | configure.ac | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/configure.ac b/configure.ac index 5b764fce..193e2d6d 100644 --- a/configure.ac +++ b/configure.ac @@ -859,11 +859,12 @@ AC_COMPILE_IFELSE([ ], [ AC_MSG_RESULT([no]) ]) - CFLAGS="$OLD_CFLAGS" -# __attribute__((__ifunc__())) can be used for one-time initializations, -# similar to __attribute__((__constructor__)). +# __attribute__((__ifunc__())) can be used to choose between different +# implementations of the same function at runtime. This is slightly more +# efficient than using __attribute__((__constructor__)) and setting +# a function pointer. AC_ARG_ENABLE([ifunc], [AS_HELP_STRING([--disable-ifunc], [do not use __attribute__((__ifunc__()))])], [], [enable_ifunc=yes]) @@ -876,7 +877,7 @@ if test "x$enable_ifunc" = xyes ; then static void func(void) { return; } static void (*resolve_func (void)) (void) { return func; } void func_ifunc (void) - __attribute__ ((__ifunc__ ("resolve_func"))); + __attribute__((__ifunc__("resolve_func"))); ], [ AC_DEFINE([HAVE_FUNC_ATTRIBUTE_IFUNC], [1], [Define to 1 if __attribute__((__ifunc__())) |