Hello,
As discussed here, the current behavior of -ftls-model is intended:
http://gcc.gnu.org/ml/gcc/2013-07/msg00248.html
(in short: unlike the attribute, -ftls-model sets a "most general" model to be
used, but the compiler can use a less general model than specified, making it
impossible to set global-dynamic model on the command line for non-PIC code).
I'd like to add a clarification to the docs. OK for trunk?
2013-07-24 Alexander Monakov <amona...@ispras.ru>
* doc/invoke.texi: Mention that -ftls-model does not force the final
model.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index d99d217..4d1fbee 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -20802,6 +20802,9 @@ Not all targets provide complete support for this
switch.
Alter the thread-local storage model to be used (@pxref{Thread-Local}).
The @var{model} argument should be one of @code{global-dynamic},
@code{local-dynamic}, @code{initial-exec} or @code{local-exec}.
+Note that the choice is subject to optimization: the compiler may use
+a more efficient model for symbols not visible outside of the translation
+unit, or if @option{-fpic} is not given on the command line.
The default without @option{-fpic} is @code{initial-exec}; with
@option{-fpic} the default is @code{global-dynamic}.
