It seems we documented libitm, and forgot to document the main switch :).
OK for branch?
* doc/invoke.texi (C Dialect Options): Document -fgnu-tm.
Index: doc/invoke.texi
===================================================================
--- doc/invoke.texi (revision 180772)
+++ doc/invoke.texi (working copy)
@@ -1715,6 +1715,18 @@ Program Interface v3.0 @w{@uref{http://w
implies @option{-pthread}, and thus is only supported on targets that
have support for @option{-pthread}.
+@item -fgnu-tm
+@opindex fgnu-tm
+When the option @option{-fgnu-tm} is specified, the compiler will
+generate code for the Linux variant of Intel's current Transactional
+Memory ABI specification document (Revision 1.1, May 6 2009). This is
+an experimental feature whose interface may change in future versions
+of GCC, as the official specification changes. Please note that not
+all architectures are supported for this feature.
+
+For more information on GCC's support for transactional memory, see
+the accompanying documentation for @file{libitm}.
+
@item -fms-extensions
@opindex fms-extensions
Accept some non-standard constructs used in Microsoft header files.
