On Tue, Jan 7, 2014 at 8:39 PM, Jakub Jelinek <ja...@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...
>
> The following patch does that, bootstrapped/regtested on x86_64-linux and
> i686-linux. The only problem with the patch is PCH,
> +FAIL: 17_intro/headers/c++200x/stdc++.cc (test for excess errors)
> +FAIL: 17_intro/headers/c++200x/stdc++_multiple_inclusion.cc (test for excess
> errors)
> (both 32-bit and 64-bit regtests), where it ICEs. I guess the problem is
> that the target globals are allocated partly in GC, partly in heap and
> even if they were allocated completely in GC and GTY(()) marked fully all
> the individual pointed structures, we IMNSHO still don't want it to be
> saved during PCH and restored later, what we have is basically just a cache
> of the target globals.
>
> Dunno what is the best way to handle that though.
> Either before writing PCH c-common.c could call some tree.c routine that
> would traverse the cl_option_hash_table hash table and for every
> TARGET_OPTION_NODE in the hash table clear TREE_TARGET_GLOBALS.
> Or perhaps some gengtype extension to run some routine before PCH saving
> on the tree_target_option structs and clear the globals field in there.
> Or use GTY((user)) on tree_target_option, but then dunno how we'd handle the
> marking of the embedded opts field (and common).
> Any ideas?
Well, a GTY((skip_pch)) would probably work. Or move the thing
out-of GC land (thus make cl_option_hash_table persistant) and
simply GTY((skip)) the pointer completely. Not sure if we ever
collect from it.
Richard.
> 2014-01-07 Jakub Jelinek <ja...@redhat.com>
>
> PR target/58115
> * tree-core.h (struct target_globals): New forward declaration.
> (struct tree_target_option): Add globals field.
> * tree.h (TREE_TARGET_GLOBALS): Define.
> * target-globals.h (struct target_globals): Define even if
> !SWITCHABLE_TARGET.
> * config/i386/i386.h (SWITCHABLE_TARGET): Define.
> * config/i386/i386.c: Include target-globals.h.
> (ix86_set_current_function): Instead of doing target_reinit
> unconditionally, use save_target_globals_default_opts and
> restore_target_globals.
>
> --- gcc/tree-core.h.jj 2014-01-07 08:47:24.000000000 +0100
> +++ gcc/tree-core.h 2014-01-07 16:44:35.591358235 +0100
> @@ -1557,11 +1557,18 @@ struct GTY(()) tree_optimization_option
> struct target_optabs *GTY ((skip)) base_optabs;
> };
>
> +/* Forward declaration, defined in target-globals.h. */
> +
> +struct GTY(()) target_globals;
> +
> /* Target options used by a function. */
>
> struct GTY(()) tree_target_option {
> struct tree_common common;
>
> + /* Target globals for the corresponding target option. */
> + struct target_globals *globals;
> +
> /* The optimization options used by the user. */
> struct cl_target_option opts;
> };
> --- gcc/tree.h.jj 2014-01-03 11:40:33.000000000 +0100
> +++ gcc/tree.h 2014-01-07 12:55:39.137295100 +0100
> @@ -2695,6 +2695,9 @@ extern tree build_optimization_node (str
> #define TREE_TARGET_OPTION(NODE) \
> (&TARGET_OPTION_NODE_CHECK (NODE)->target_option.opts)
>
> +#define TREE_TARGET_GLOBALS(NODE) \
> + (TARGET_OPTION_NODE_CHECK (NODE)->target_option.globals)
> +
> /* Return a tree node that encapsulates the target options in OPTS. */
> extern tree build_target_option_node (struct gcc_options *opts);
>
> --- gcc/target-globals.h.jj 2014-01-03 11:40:46.000000000 +0100
> +++ gcc/target-globals.h 2014-01-07 17:08:51.113880947 +0100
> @@ -37,6 +37,7 @@ extern struct target_builtins *this_targ
> extern struct target_gcse *this_target_gcse;
> extern struct target_bb_reorder *this_target_bb_reorder;
> extern struct target_lower_subreg *this_target_lower_subreg;
> +#endif
>
> struct GTY(()) target_globals {
> struct target_flag_state *GTY((skip)) flag_state;
> @@ -57,6 +58,7 @@ struct GTY(()) target_globals {
> struct target_lower_subreg *GTY((skip)) lower_subreg;
> };
>
> +#if SWITCHABLE_TARGET
> extern struct target_globals default_target_globals;
>
> extern struct target_globals *save_target_globals (void);
> --- gcc/config/i386/i386.h.jj 2014-01-06 22:37:19.000000000 +0100
> +++ gcc/config/i386/i386.h 2014-01-07 12:13:06.480486755 +0100
> @@ -2510,6 +2510,9 @@ extern void debug_dispatch_window (int);
> #define IX86_HLE_ACQUIRE (1 << 16)
> #define IX86_HLE_RELEASE (1 << 17)
>
> +/* For switching between functions with different target attributes. */
> +#define SWITCHABLE_TARGET 1
> +
> /*
> Local variables:
> version-control: t
> --- gcc/config/i386/i386.c.jj 2014-01-06 22:37:19.000000000 +0100
> +++ gcc/config/i386/i386.c 2014-01-07 16:52:32.597904760 +0100
> @@ -80,6 +80,7 @@ along with GCC; see the file COPYING3.
> #include "tree-pass.h"
> #include "context.h"
> #include "pass_manager.h"
> +#include "target-globals.h"
>
> static rtx legitimize_dllimport_symbol (rtx, bool);
> static rtx legitimize_pe_coff_extern_decl (rtx, bool);
> @@ -4868,16 +4869,25 @@ ix86_set_current_function (tree fndecl)
> {
> cl_target_option_restore (&global_options,
> TREE_TARGET_OPTION (new_tree));
> - target_reinit ();
> + if (TREE_TARGET_GLOBALS (new_tree))
> + restore_target_globals (TREE_TARGET_GLOBALS (new_tree));
> + else
> + TREE_TARGET_GLOBALS (new_tree)
> + = save_target_globals_default_opts ();
> }
>
> else if (old_tree)
> {
> - struct cl_target_option *def
> - = TREE_TARGET_OPTION (target_option_current_node);
> -
> - cl_target_option_restore (&global_options, def);
> - target_reinit ();
> + new_tree = target_option_current_node;
> + cl_target_option_restore (&global_options,
> + TREE_TARGET_OPTION (new_tree));
> + if (TREE_TARGET_GLOBALS (new_tree))
> + restore_target_globals (TREE_TARGET_GLOBALS (new_tree));
> + else if (new_tree == target_option_default_node)
> + restore_target_globals (&default_target_globals);
> + else
> + TREE_TARGET_GLOBALS (new_tree)
> + = save_target_globals_default_opts ();
> }
> }
> }
>
>
> Jakub
