| 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_COMPILE_IFELSE([AC_LANG_PROGRAM([[ | |
| int foo(int); | |
| int foo(int i) { | |
| static void *label[] = { &&l1, &&l2 }; | |
| goto *label[i]; | |
| l1: return 1; | |
| l2: return 2; | |
| } | |
| ]], | |
| [[foo(1);]])], | |
| [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 | |
| ]) | |