libgomp/libgomp.texi: Mention -fno-builtin-omp_is_initial_device

libgomp/ChangeLog:

	* libgomp.texi (omp_is_initial_device): Mention
	-fno-builtin-omp_is_initial_device and folding by default.

diff --git a/libgomp/libgomp.texi b/libgomp/libgomp.texi
index c6759dd03bc3134ed7267ea2a54a2a14edafc63f..081e22510a5d2e4cb9259ee85bb3e2a45b1b5af5 100644 (file)
--- a/libgomp/libgomp.texi
+++ b/libgomp/libgomp.texi
@@ -1754,6 +1754,10 @@ This function returns @code{true} if currently running on the host device,
 @code{false} otherwise.  Here, @code{true} and @code{false} represent
 their language-specific counterparts.
 
+Note that in GCC this value is already folded to a constant in the compiler;
+compile with @option{-fno-builtin-omp_is_initial_device} if a run-time function
+is desired.
+
 @item @emph{C/C++}:
 @multitable @columnfractions .20 .80
 @item @emph{Prototype}: @tab @code{int omp_is_initial_device(void);}