"F. Laupretre" <[EMAIL PROTECTED]> writes: > In order for the check to be done correctly, we have to provide a > program that the compiler cannot optimize, ie where it cannot detect > that the call is useless, even if it is very very smart. Here is a > patch with such a program.
I haven't got a lot of faith in your proposed patch --- with sufficiently aggressive optimization, the compiler might inline the is_f() function, no? After looking at the modern version of AC_CHECK_FUNC, I'm thinking that the best answer is to make the finite() result affect the program's exit status. Would you try this version of the check and see if it works for you? AC_TRY_LINK([#include <math.h>], [return finite(1.0) ? 0 : 1;], [AC_DEFINE(HAVE_FINITE, 1, [Define to 1 if you have finite().]) AC_MSG_RESULT(yes)], [AC_MSG_RESULT(no)]) regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend