| 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 | ]) |