[bpt/guile.git] / m4 / labels-as-values.m4

dnl check for gcc's "labels as values" feature
AC_DEFUN(AC_C_LABELS_AS_VALUES,
[AC_CACHE_CHECK([labels as values], ac_cv_labels_as_values,
[AC_TRY_COMPILE([
int foo(int);
int foo(i)
int i; { 
static void *label[] = { &&l1, &&l2 };
goto *label[i];
l1: return 1;
l2: return 2;
}
],
[int i;], 
ac_cv_labels_as_values=yes,
ac_cv_labels_as_values=no)])
if test "$ac_cv_labels_as_values" = yes; then
AC_DEFINE(HAVE_LABELS_AS_VALUES, [],
          [Define if compiler supports gcc's "labels as values" (aka computed goto)
           feature, used to speed up instruction dispatch in the interpreter.])
fi
])
Commit	Line	Data
659b4611 AW	1	dnl check for gcc's "labels as values" feature
	2	AC_DEFUN(AC_C_LABELS_AS_VALUES,
	3	[AC_CACHE_CHECK([labels as values], ac_cv_labels_as_values,
	4	[AC_TRY_COMPILE([
	5	int foo(int);
	6	int foo(i)
	7	int i; {
	8	static void *label[] = { &&l1, &&l2 };
	9	goto *label[i];
	10	l1: return 1;
	11	l2: return 2;
	12	}
	13	],
	14	[int i;],
	15	ac_cv_labels_as_values=yes,
	16	ac_cv_labels_as_values=no)])
	17	if test "$ac_cv_labels_as_values" = yes; then
	18	AC_DEFINE(HAVE_LABELS_AS_VALUES, [],
	19	[Define if compiler supports gcc's "labels as values" (aka computed goto)
	20	feature, used to speed up instruction dispatch in the interpreter.])
	21	fi
	22	])