| Message ID | 87eh4kvs2e.fsf@talisman.default |
|---|---|
| State | New |
| Headers | show |
On Mon, 6 Jan 2014 19:16:57, Richard Saniford wrote: > > Bernd Edlinger <bernd.edlinger@hotmail.de> writes: >>> >>> Jakub Jelinek <jakub@redhat.com> wrote: >>>>On Mon, Jan 06, 2014 at 10:27:06AM +0000, Richard Sandiford wrote: >>>>> Of course, IMO, the cleanest fix would be to use switchable targets >>>>> for i386... >>>> >>>>We IMHO want that anyway, e.g. #pragma omp declare simd tests take eons >>>>to >>>>compile because even with just a few routines in a CU there are >>>>hundreds or >>>>thousands of IRA reinitializations. >>> >>> We also want a big fat comment before the non-obvious order of inits >>> when switching cfuns. >>> >>> Bernd, please revert your patch for now. >>> >> >> OK, reverted for now. > > Thanks Bernd. (And sorry for the tone of my original message -- wasn't happy > with that when I read it back.) > No problem, Richard, I don't see this personally in any way. > How about this patch for the big comment? > The comment should say that target_set_current_function() cannot call target_reinit() because: target_reinit()=>lang_dependent_init_target() =>init_optabs()=>init_all_optabs(this_fn_optabs); uses this_fn_optabs which is undefined here. However many targets (nios2, rx, i386, rs6000) do exactly that. Is there currently any target, that sets this_target_optab in the target_set_current_function? Regards, Bernd. > Thanks, > Richard > > > gcc/ > * function.c (invoke_set_current_function_hook): Add more commentary. > > Index: gcc/function.c > =================================================================== > --- gcc/function.c 2014-01-06 19:09:27.821167117 +0000 > +++ gcc/function.c 2014-01-06 19:15:27.764240857 +0000 > @@ -4405,9 +4405,23 @@ invoke_set_current_function_hook (tree f > cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts)); > } > > + /* Give the target an opportunity to change the global state in > + response to function attributes. This includes picking the > + correct value of this_target on SWITCHABLE_TARGET targets. > + > + Note that this_target (and in particular this_target_optabs) > + should always reflect the target state with default optimization > + options. We therefore call the target hook first and then apply > + any function-specific optimization options on top. */ > targetm.set_current_function (fndecl); > + > + /* Set this_fn_optabs appropriately, on the assumption that we > + want the default optimization options. */ > this_fn_optabs = this_target_optabs; > > + /* Now adjust this_fn_optabs if using non-default optimization options. > + init_tree_optimization_optabs ensures that the cached value of > + TREE_OPTIMIZATION_OPTABS (opts) is correct for this_target. */ > if (opts != optimization_default_node) > { > init_tree_optimization_optabs (opts);
Index: gcc/function.c =================================================================== --- gcc/function.c 2014-01-06 19:09:27.821167117 +0000 +++ gcc/function.c 2014-01-06 19:15:27.764240857 +0000 @@ -4405,9 +4405,23 @@ invoke_set_current_function_hook (tree f cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts)); } + /* Give the target an opportunity to change the global state in + response to function attributes. This includes picking the + correct value of this_target on SWITCHABLE_TARGET targets. + + Note that this_target (and in particular this_target_optabs) + should always reflect the target state with default optimization + options. We therefore call the target hook first and then apply + any function-specific optimization options on top. */ targetm.set_current_function (fndecl); + + /* Set this_fn_optabs appropriately, on the assumption that we + want the default optimization options. */ this_fn_optabs = this_target_optabs; + /* Now adjust this_fn_optabs if using non-default optimization options. + init_tree_optimization_optabs ensures that the cached value of + TREE_OPTIMIZATION_OPTABS (opts) is correct for this_target. */ if (opts != optimization_default_node) { init_tree_optimization_optabs (opts);