===================================================================
@@ -10997,6 +10997,14 @@ The result is another tree containing a simplified
call's result. If @var{ignore} is true the value will be ignored.
@end deftypefn
+@deftypefn {Target Hook} int TARGET_DISPATCH_VERSION (tree @var{dispatch_decl}, void *@var{fndecls}, basic_block *@var{empty_bb})
+For multi-versioned function, this hook sets up the dispatcher.
+@var{dispatch_decl} is the function that will be used to dispatch the
+version. @var{fndecls} are the function choices for dispatch.
+@var{empty_bb} is an basic block in @var{dispatch_decl} where the
+code to do the dispatch will be added.
+@end deftypefn
+
@deftypefn {Target Hook} {const char *} TARGET_INVALID_WITHIN_DOLOOP (const_rtx @var{insn})
Take an instruction in @var{insn} and return NULL if it is valid within a
===================================================================
@@ -10877,6 +10877,14 @@ The result is another tree containing a simplified
call's result. If @var{ignore} is true the value will be ignored.
@end deftypefn
+@hook TARGET_DISPATCH_VERSION
+For multi-versioned function, this hook sets up the dispatcher.
+@var{dispatch_decl} is the function that will be used to dispatch the
+version. @var{fndecls} are the function choices for dispatch.
+@var{empty_bb} is an basic block in @var{dispatch_decl} where the
+code to do the dispatch will be added.
+@end deftypefn
+
@hook TARGET_INVALID_WITHIN_DOLOOP
Take an instruction in @var{insn} and return NULL if it is valid within a
===================================================================
@@ -1249,6 +1249,15 @@ DEFHOOK
tree, (tree fndecl, int n_args, tree *argp, bool ignore),
hook_tree_tree_int_treep_bool_null)
+/* Target hook to generate the dispatching code for calls to multi-versioned
+ functions. DISPATCH_DECL is the function that will have the dispatching
+ logic. FNDECLS are the list of choices for dispatch and EMPTY_BB is the
+ basic bloc in DISPATCH_DECL which will contain the code. */
+DEFHOOK
+(dispatch_version,
+ "",
+ int, (tree dispatch_decl, void *fndecls, basic_block *empty_bb), NULL)
+
/* Returns a code for a target-specific builtin that implements
reciprocal of the function, or NULL_TREE if not available. */
DEFHOOK
===================================================================
@@ -3539,6 +3539,12 @@ extern VEC(tree, gc) **decl_debug_args_insert (tre
#define DECL_FUNCTION_SPECIFIC_OPTIMIZATION(NODE) \
(FUNCTION_DECL_CHECK (NODE)->function_decl.function_specific_optimization)
+/* In FUNCTION_DECL, this is set if this function has other versions generated
+ using "target" attributes. The default version is the one which does not
+ have any "target" attribute set. */
+#define DECL_FUNCTION_VERSIONED(NODE)\
+ (FUNCTION_DECL_CHECK (NODE)->function_decl.versioned_function)
+
/* FUNCTION_DECL inherits from DECL_NON_COMMON because of the use of the
arguments/result/saved_tree fields by front ends. It was either inherit
FUNCTION_DECL from non_common, or inherit non_common from FUNCTION_DECL,
@@ -3583,8 +3589,8 @@ struct GTY(()) tree_function_decl {
unsigned looping_const_or_pure_flag : 1;
unsigned has_debug_args_flag : 1;
unsigned tm_clone_flag : 1;
-
- /* 1 bit left */
+ unsigned versioned_function : 1;
+ /* No bits left. */
};
/* The source language of the translation-unit. */
===================================================================
@@ -453,6 +453,7 @@ extern struct gimple_opt_pass pass_tm_memopt;
extern struct gimple_opt_pass pass_tm_edges;
extern struct gimple_opt_pass pass_split_functions;
extern struct gimple_opt_pass pass_feedback_split_functions;
+extern struct gimple_opt_pass pass_dispatch_versions;
/* IPA Passes */
extern struct simple_ipa_opt_pass pass_ipa_lower_emutls;
===================================================================
@@ -0,0 +1,832 @@
+/* Function Multiversioning.
+ Copyright (C) 2012 Free Software Foundation, Inc.
+ Contributed by Sriraman Tallam (tmsriram@google.com)
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+/* Holds the state for multi-versioned functions here. The front-end
+ updates the state as and when function versions are encountered.
+ This is then used to generate the dispatch code. Also, the
+ optimization passes to clone hot paths involving versioned functions
+ will be done here.
+
+ Function versions are created by using the same function signature but
+ also tagging attribute "target" to specify the platform type for which
+ the version must be executed. Here is an example:
+
+ int foo ()
+ {
+ printf ("Execute as default");
+ return 0;
+ }
+
+ int __attribute__ ((target ("arch=corei7")))
+ foo ()
+ {
+ printf ("Execute for corei7");
+ return 0;
+ }
+
+ int main ()
+ {
+ return foo ();
+ }
+
+ The call to foo in main is replaced with a call to an IFUNC function that
+ contains the dispatch code to call the correct function version at
+ run-time. */
+
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "tree.h"
+#include "tree-inline.h"
+#include "langhooks.h"
+#include "flags.h"
+#include "cgraph.h"
+#include "diagnostic.h"
+#include "toplev.h"
+#include "timevar.h"
+#include "params.h"
+#include "fibheap.h"
+#include "intl.h"
+#include "tree-pass.h"
+#include "hashtab.h"
+#include "coverage.h"
+#include "ggc.h"
+#include "tree-flow.h"
+#include "rtl.h"
+#include "ipa-prop.h"
+#include "basic-block.h"
+#include "toplev.h"
+#include "dbgcnt.h"
+#include "tree-dump.h"
+#include "output.h"
+#include "vecprim.h"
+#include "gimple-pretty-print.h"
+#include "ipa-inline.h"
+#include "target.h"
+#include "multiversion.h"
+
+typedef void * void_p;
+
+DEF_VEC_P (void_p);
+DEF_VEC_ALLOC_P (void_p, heap);
+
+/* Each function decl that is a function version gets an instance of this
+ structure. Since this is called by the front-end, decl merging can
+ happen, where a decl created for a new declaration is merged with
+ the old. In this case, the new decl is deleted and the IS_DELETED
+ field is set for the struct instance corresponding to the new decl.
+ IFUNC_DECL is the decl of the ifunc function for default decls.
+ IFUNC_RESOLVER_DECL is the decl of the dispatch function. VERSIONS
+ is a vector containing the list of function versions that are
+ the candidates for dispatch. */
+
+typedef struct version_function_d {
+ tree decl;
+ tree ifunc_decl;
+ tree ifunc_resolver_decl;
+ VEC (void_p, heap) *versions;
+ bool is_deleted;
+} version_function;
+
+/* Hashmap has an entry for every function decl that has other function
+ versions. For function decls that are the default, it also stores the
+ list of all the other function versions. Each entry is a structure
+ of type version_function_d. */
+static htab_t decl_version_htab = NULL;
+
+/* Hashtable helpers for decl_version_htab. */
+
+static hashval_t
+decl_version_htab_hash_descriptor (const void *p)
+{
+ const version_function *t = (const version_function *) p;
+ return htab_hash_pointer (t->decl);
+}
+
+/* Hashtable helper for decl_version_htab. */
+
+static int
+decl_version_htab_eq_descriptor (const void *p1, const void *p2)
+{
+ const version_function *t1 = (const version_function *) p1;
+ return htab_eq_pointer ((const void_p) t1->decl, p2);
+}
+
+/* Create the decl_version_htab. */
+static void
+create_decl_version_htab (void)
+{
+ if (decl_version_htab == NULL)
+ decl_version_htab = htab_create (10, decl_version_htab_hash_descriptor,
+ decl_version_htab_eq_descriptor, NULL);
+}
+
+/* Creates an instance of version_function for decl DECL. */
+
+static version_function*
+new_version_function (const tree decl)
+{
+ version_function *v;
+ v = (version_function *)xmalloc(sizeof (version_function));
+ v->decl = decl;
+ v->ifunc_decl = NULL;
+ v->ifunc_resolver_decl = NULL;
+ v->versions = NULL;
+ v->is_deleted = false;
+ return v;
+}
+
+/* Comparator function to be used in qsort routine to sort attribute
+ specification strings to "target". */
+
+static int
+attr_strcmp (const void *v1, const void *v2)
+{
+ const char *c1 = *(char *const*)v1;
+ const char *c2 = *(char *const*)v2;
+ return strcmp (c1, c2);
+}
+
+/* STR is the argument to target attribute. This function tokenizes
+ the comma separated arguments, sorts them and returns a string which
+ is a unique identifier for the comma separated arguments. */
+
+static char *
+sorted_attr_string (const char *str)
+{
+ char **args = NULL;
+ char *attr_str, *ret_str;
+ char *attr = NULL;
+ unsigned int argnum = 1;
+ unsigned int i;
+
+ for (i = 0; i < strlen (str); i++)
+ if (str[i] == ',')
+ argnum++;
+
+ attr_str = (char *)xmalloc (strlen (str) + 1);
+ strcpy (attr_str, str);
+
+ for (i = 0; i < strlen (attr_str); i++)
+ if (attr_str[i] == '=')
+ attr_str[i] = '_';
+
+ if (argnum == 1)
+ return attr_str;
+
+ args = (char **)xmalloc (argnum * sizeof (char *));
+
+ i = 0;
+ attr = strtok (attr_str, ",");
+ while (attr != NULL)
+ {
+ args[i] = attr;
+ i++;
+ attr = strtok (NULL, ",");
+ }
+
+ qsort (args, argnum, sizeof (char*), attr_strcmp);
+
+ ret_str = (char *)xmalloc (strlen (str) + 1);
+ strcpy (ret_str, args[0]);
+ for (i = 1; i < argnum; i++)
+ {
+ strcat (ret_str, "_");
+ strcat (ret_str, args[i]);
+ }
+
+ free (args);
+ free (attr_str);
+ return ret_str;
+}
+
+/* Returns true when only one of DECL1 and DECL2 is marked with "target"
+ or if the "target" attribute strings of DECL1 and DECL2 dont match. */
+
+bool
+has_different_version_attributes (const tree decl1, const tree decl2)
+{
+ tree attr1, attr2;
+ char *c1, *c2;
+ bool ret = false;
+
+ if (TREE_CODE (decl1) != FUNCTION_DECL
+ || TREE_CODE (decl2) != FUNCTION_DECL)
+ return false;
+
+ attr1 = lookup_attribute ("target", DECL_ATTRIBUTES (decl1));
+ attr2 = lookup_attribute ("target", DECL_ATTRIBUTES (decl2));
+
+ if (attr1 == NULL_TREE && attr2 == NULL_TREE)
+ return false;
+
+ if ((attr1 == NULL_TREE && attr2 != NULL_TREE)
+ || (attr1 != NULL_TREE && attr2 == NULL_TREE))
+ return true;
+
+ c1 = sorted_attr_string (
+ TREE_STRING_POINTER (TREE_VALUE (TREE_VALUE (attr1))));
+ c2 = sorted_attr_string (
+ TREE_STRING_POINTER (TREE_VALUE (TREE_VALUE (attr2))));
+
+ if (strcmp (c1, c2) != 0)
+ ret = true;
+
+ free (c1);
+ free (c2);
+
+ return ret;
+}
+
+/* If this decl corresponds to a function and has "target" attribute,
+ append the attribute string to its assembler name. */
+
+static void
+version_assembler_name (const tree decl)
+{
+ tree version_attr;
+ const char *orig_name, *version_string, *attr_str;
+ char *assembler_name;
+ tree assembler_name_tree;
+
+ if (TREE_CODE (decl) != FUNCTION_DECL)
+ return;
+
+ if (DECL_DECLARED_INLINE_P (decl)
+ &&lookup_attribute ("gnu_inline",
+ DECL_ATTRIBUTES (decl)))
+ error_at (DECL_SOURCE_LOCATION (decl),
+ "Function versions cannot be marked as gnu_inline,"
+ " bodies have to be generated\n");
+
+ if (DECL_VIRTUAL_P (decl)
+ || DECL_VINDEX (decl))
+ error_at (DECL_SOURCE_LOCATION (decl),
+ "Virtual function versioning not supported\n");
+
+ version_attr = lookup_attribute ("target", DECL_ATTRIBUTES (decl));
+ /* target attribute string is NULL for default functions. */
+ if (version_attr == NULL_TREE)
+ return;
+
+ orig_name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
+ version_string
+ = TREE_STRING_POINTER (TREE_VALUE (TREE_VALUE (version_attr)));
+
+ attr_str = sorted_attr_string (version_string);
+ assembler_name = (char *) xmalloc (strlen (orig_name)
+ + strlen (attr_str) + 2);
+
+ sprintf (assembler_name, "%s.%s", orig_name, attr_str);
+ if (dump_file)
+ fprintf (dump_file, "Assembler name set to %s for function version %s\n",
+ assembler_name, IDENTIFIER_POINTER (DECL_NAME (decl)));
+
+ assembler_name_tree = get_identifier (assembler_name);
+
+ SET_DECL_ASSEMBLER_NAME (decl, assembler_name_tree);
+ SET_DECL_RTL (decl, NULL);
+}
+
+void
+mark_function_as_version (const tree decl)
+{
+ if (DECL_FUNCTION_VERSIONED (decl))
+ return;
+ DECL_FUNCTION_VERSIONED (decl) = 1;
+ version_assembler_name (decl);
+}
+
+/* Returns true if function DECL has target attribute set. This could be
+ a version. */
+
+bool
+is_target_attribute_set (const tree decl)
+{
+ return (TREE_CODE (decl) == FUNCTION_DECL
+ && (lookup_attribute ("target", DECL_ATTRIBUTES (decl))
+ != NULL_TREE));
+}
+
+/* Returns true if decl is multi-versioned and DECL is the default function,
+ that is it is not tagged with "target" attribute. */
+
+bool
+is_default_function (const tree decl)
+{
+ return (TREE_CODE (decl) == FUNCTION_DECL
+ && DECL_FUNCTION_VERSIONED (decl)
+ && (lookup_attribute ("target", DECL_ATTRIBUTES (decl))
+ == NULL_TREE));
+}
+
+/* For function decl DECL, find the version_function struct in the
+ decl_version_htab. */
+
+static version_function *
+find_function_version (const tree decl)
+{
+ void *slot;
+
+ if (!DECL_FUNCTION_VERSIONED (decl))
+ return NULL;
+
+ if (!decl_version_htab)
+ return NULL;
+
+ slot = htab_find_with_hash (decl_version_htab, decl,
+ htab_hash_pointer (decl));
+
+ if (slot != NULL)
+ return (version_function *)slot;
+
+ return NULL;
+}
+
+/* Record DECL as a function version by creating a version_function struct
+ for it and storing it in the hashtable. */
+
+static version_function *
+add_function_version (const tree decl)
+{
+ void **slot;
+ version_function *v;
+
+ if (!DECL_FUNCTION_VERSIONED (decl))
+ return NULL;
+
+ create_decl_version_htab ();
+
+ slot = htab_find_slot_with_hash (decl_version_htab, (const void_p)decl,
+ htab_hash_pointer ((const void_p)decl),
+ INSERT);
+
+ if (*slot != NULL)
+ return (version_function *)*slot;
+
+ v = new_version_function (decl);
+ *slot = v;
+
+ return v;
+}
+
+/* Push V into VEC only if it is not already present. If already present
+ returns false. */
+
+static bool
+push_function_version (version_function *v, VEC (void_p, heap) **vec)
+{
+ int ix;
+ void_p ele;
+ for (ix = 0; VEC_iterate (void_p, *vec, ix, ele); ++ix)
+ {
+ if (ele == (void_p)v)
+ return false;
+ }
+
+ VEC_safe_push (void_p, heap, *vec, (void*)v);
+ return true;
+}
+
+/* Mark DECL as deleted. This is called by the front-end when a duplicate
+ decl is merged with the original decl and the duplicate decl is deleted.
+ This function marks the duplicate_decl as invalid. Called by
+ duplicate_decls in cp/decl.c. */
+
+void
+mark_delete_decl_version (const tree decl)
+{
+ version_function *decl_v;
+
+ decl_v = find_function_version (decl);
+
+ if (decl_v == NULL)
+ return;
+
+ decl_v->is_deleted = true;
+
+ if (is_default_function (decl)
+ && decl_v->versions != NULL)
+ {
+ VEC_truncate (void_p, decl_v->versions, 0);
+ VEC_free (void_p, heap, decl_v->versions);
+ decl_v->versions = NULL;
+ }
+}
+
+/* Mark DECL1 and DECL2 to be function versions in the same group. One
+ of DECL1 and DECL2 must be the default, otherwise this function does
+ nothing. This function aggregates the versions. */
+
+int
+group_function_versions (const tree decl1, const tree decl2)
+{
+ tree default_decl, version_decl;
+ version_function *default_v, *version_v;
+
+ gcc_assert (DECL_FUNCTION_VERSIONED (decl1)
+ && DECL_FUNCTION_VERSIONED (decl2));
+
+ /* The version decls are added only to the default decl. */
+ if (!is_default_function (decl1)
+ && !is_default_function (decl2))
+ return 0;
+
+ /* This can happen with duplicate declarations. Just ignore. */
+ if (is_default_function (decl1)
+ && is_default_function (decl2))
+ return 0;
+
+ default_decl = (is_default_function (decl1)) ? decl1 : decl2;
+ version_decl = (default_decl == decl1) ? decl2 : decl1;
+
+ gcc_assert (default_decl != version_decl);
+ create_decl_version_htab ();
+
+ /* If the version function is found, it has been added. */
+ if (find_function_version (version_decl))
+ return 0;
+
+ default_v = add_function_version (default_decl);
+ version_v = add_function_version (version_decl);
+
+ if (default_v->versions == NULL)
+ default_v->versions = VEC_alloc (void_p, heap, 1);
+
+ push_function_version (version_v, &default_v->versions);
+ return 0;
+}
+
+/* Makes a function attribute of the form NAME(ARG_NAME) and chains
+ it to CHAIN. */
+
+static tree
+make_attribute (const char *name, const char *arg_name, tree chain)
+{
+ tree attr_name;
+ tree attr_arg_name;
+ tree attr_args;
+ tree attr;
+
+ attr_name = get_identifier (name);
+ attr_arg_name = build_string (strlen (arg_name), arg_name);
+ attr_args = tree_cons (NULL_TREE, attr_arg_name, NULL_TREE);
+ attr = tree_cons (attr_name, attr_args, chain);
+ return attr;
+}
+
+/* Return a new name by appending SUFFIX to the DECL name. If
+ make_unique is true, append the full path name. */
+
+static char *
+make_name (tree decl, const char *suffix, bool make_unique)
+{
+ char *global_var_name;
+ int name_len;
+ const char *name;
+ const char *unique_name = NULL;
+
+ name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
+
+ /* Get a unique name that can be used globally without any chances
+ of collision at link time. */
+ if (make_unique)
+ unique_name = IDENTIFIER_POINTER (get_file_function_name ("\0"));
+
+ name_len = strlen (name) + strlen (suffix) + 2;
+
+ if (make_unique)
+ name_len += strlen (unique_name) + 1;
+ global_var_name = (char *) xmalloc (name_len);
+
+ /* Use '.' to concatenate names as it is demangler friendly. */
+ if (make_unique)
+ snprintf (global_var_name, name_len, "%s.%s.%s", name,
+ unique_name, suffix);
+ else
+ snprintf (global_var_name, name_len, "%s.%s", name, suffix);
+
+ return global_var_name;
+}
+
+/* Make the resolver function decl for ifunc (IFUNC_DECL) to dispatch
+ the versions of multi-versioned function DEFAULT_DECL. Create and
+ empty basic block in the resolver and store the pointer in
+ EMPTY_BB. Return the decl of the resolver function. */
+
+static tree
+make_ifunc_resolver_func (const tree default_decl,
+ const tree ifunc_decl,
+ basic_block *empty_bb)
+{
+ char *resolver_name;
+ tree decl, type, decl_name, t;
+ basic_block new_bb;
+ tree old_current_function_decl;
+ bool make_unique = false;
+
+ /* IFUNC's have to be globally visible. So, if the default_decl is
+ not, then the name of the IFUNC should be made unique. */
+ if (TREE_PUBLIC (default_decl) == 0)
+ make_unique = true;
+
+ /* Append the filename to the resolver function if the versions are
+ not externally visible. This is because the resolver function has
+ to be externally visible for the loader to find it. So, appending
+ the filename will prevent conflicts with a resolver function from
+ another module which is based on the same version name. */
+ resolver_name = make_name (default_decl, "resolver", make_unique);
+
+ /* The resolver function should return a (void *). */
+ type = build_function_type_list (ptr_type_node, NULL_TREE);
+
+ decl = build_fn_decl (resolver_name, type);
+ decl_name = get_identifier (resolver_name);
+ SET_DECL_ASSEMBLER_NAME (decl, decl_name);
+
+ DECL_NAME (decl) = decl_name;
+ TREE_USED (decl) = TREE_USED (default_decl);
+ DECL_ARTIFICIAL (decl) = 1;
+ DECL_IGNORED_P (decl) = 0;
+ /* IFUNC resolvers have to be externally visible. */
+ TREE_PUBLIC (decl) = 1;
+ DECL_UNINLINABLE (decl) = 1;
+
+ DECL_EXTERNAL (decl) = DECL_EXTERNAL (default_decl);
+ DECL_EXTERNAL (ifunc_decl) = 0;
+
+ DECL_CONTEXT (decl) = NULL_TREE;
+ DECL_INITIAL (decl) = make_node (BLOCK);
+ DECL_STATIC_CONSTRUCTOR (decl) = 0;
+ TREE_READONLY (decl) = 0;
+ DECL_PURE_P (decl) = 0;
+ DECL_COMDAT (decl) = DECL_COMDAT (default_decl);
+ if (DECL_COMDAT_GROUP (default_decl))
+ {
+ make_decl_one_only (decl, DECL_COMDAT_GROUP (default_decl));
+ }
+ /* Build result decl and add to function_decl. */
+ t = build_decl (UNKNOWN_LOCATION, RESULT_DECL, NULL_TREE, ptr_type_node);
+ DECL_ARTIFICIAL (t) = 1;
+ DECL_IGNORED_P (t) = 1;
+ DECL_RESULT (decl) = t;
+
+ gimplify_function_tree (decl);
+ old_current_function_decl = current_function_decl;
+ push_cfun (DECL_STRUCT_FUNCTION (decl));
+ current_function_decl = decl;
+ init_empty_tree_cfg_for_function (DECL_STRUCT_FUNCTION (decl));
+ cfun->curr_properties |=
+ (PROP_gimple_lcf | PROP_gimple_leh | PROP_cfg | PROP_referenced_vars |
+ PROP_ssa);
+ new_bb = create_empty_bb (ENTRY_BLOCK_PTR);
+ make_edge (ENTRY_BLOCK_PTR, new_bb, EDGE_FALLTHRU);
+ make_edge (new_bb, EXIT_BLOCK_PTR, 0);
+ *empty_bb = new_bb;
+
+ cgraph_add_new_function (decl, true);
+ cgraph_call_function_insertion_hooks (cgraph_get_create_node (decl));
+ cgraph_mark_force_output_node (cgraph_get_create_node (decl));
+
+ if (DECL_COMDAT_GROUP (default_decl))
+ {
+ gcc_assert (cgraph_get_node (default_decl));
+ cgraph_add_to_same_comdat_group (cgraph_get_node (decl),
+ cgraph_get_node (default_decl));
+ }
+
+ pop_cfun ();
+ current_function_decl = old_current_function_decl;
+
+ gcc_assert (ifunc_decl != NULL);
+ /* Mark ifunc_decl as "ifunc" with resolver as resolver_name. */
+ DECL_ATTRIBUTES (ifunc_decl)
+ = make_attribute ("ifunc", resolver_name, DECL_ATTRIBUTES (ifunc_decl));
+
+ /* Create the alias here. */
+ cgraph_create_function_alias (ifunc_decl, decl);
+ return decl;
+}
+
+/* Make and ifunc declaration for the multi-versioned function DECL. Calls to
+ DECL function will be replaced with calls to the ifunc. Return the decl
+ of the ifunc created. */
+
+static tree
+make_ifunc_func (const tree decl)
+{
+ tree ifunc_decl;
+ char *ifunc_name, *resolver_name;
+ tree fn_type, ifunc_type;
+ bool make_unique = false;
+
+ if (TREE_PUBLIC (decl) == 0)
+ make_unique = true;
+
+ ifunc_name = make_name (decl, "ifunc", make_unique);
+ resolver_name = make_name (decl, "resolver", make_unique);
+ gcc_assert (resolver_name);
+
+ fn_type = TREE_TYPE (decl);
+ ifunc_type = build_function_type (TREE_TYPE (fn_type),
+ TYPE_ARG_TYPES (fn_type));
+
+ ifunc_decl = build_fn_decl (ifunc_name, ifunc_type);
+ TREE_USED (ifunc_decl) = 1;
+ DECL_CONTEXT (ifunc_decl) = NULL_TREE;
+ DECL_INITIAL (ifunc_decl) = error_mark_node;
+ DECL_ARTIFICIAL (ifunc_decl) = 1;
+ /* Mark this ifunc as external, the resolver will flip it again if
+ it gets generated. */
+ DECL_EXTERNAL (ifunc_decl) = 1;
+ /* IFUNCs have to be externally visible. */
+ TREE_PUBLIC (ifunc_decl) = 1;
+
+ return ifunc_decl;
+}
+
+/* For multi-versioned function decl, which should also be the default,
+ return the decl of the ifunc resolver, create it if it does not
+ exist. */
+
+tree
+get_ifunc_for_version (const tree decl)
+{
+ version_function *decl_v;
+ int ix;
+ void_p ele;
+
+ /* DECL has to be the default version, otherwise it is missing and
+ that is not allowed. */
+ if (!is_default_function (decl))
+ {
+ error_at (DECL_SOURCE_LOCATION (decl), "Default version not found");
+ return decl;
+ }
+
+ decl_v = find_function_version (decl);
+ gcc_assert (decl_v != NULL);
+ if (decl_v->ifunc_decl == NULL)
+ {
+ tree ifunc_decl;
+ ifunc_decl = make_ifunc_func (decl);
+ decl_v->ifunc_decl = ifunc_decl;
+ }
+
+ if (cgraph_get_node (decl))
+ cgraph_mark_force_output_node (cgraph_get_node (decl));
+
+ for (ix = 0; VEC_iterate (void_p, decl_v->versions, ix, ele); ++ix)
+ {
+ version_function *v = (version_function *) ele;
+ /* This could be a deleted version. Happens with
+ duplicate declarations. */
+ if (v->is_deleted)
+ continue;
+ gcc_assert (v->decl != NULL);
+ if (cgraph_get_node (v->decl))
+ cgraph_mark_force_output_node (cgraph_get_node (v->decl));
+ }
+
+ return decl_v->ifunc_decl;
+}
+
+/* Generate the dispatching code to dispatch multi-versioned function
+ DECL. Make a new function decl for dispatching and call the target
+ hook to process the "target" attributes and provide the code to
+ dispatch the right function at run-time. */
+
+static tree
+make_ifunc_resolver_for_version (const tree decl)
+{
+ version_function *decl_v;
+ tree ifunc_resolver_decl, ifunc_decl;
+ basic_block empty_bb;
+ int ix;
+ void_p ele;
+ VEC (tree, heap) *fn_ver_vec = NULL;
+ tree old_current_function_decl;
+
+ gcc_assert (is_default_function (decl));
+
+ decl_v = find_function_version (decl);
+ gcc_assert (decl_v != NULL);
+
+ if (decl_v->ifunc_resolver_decl != NULL)
+ return decl_v->ifunc_resolver_decl;
+
+ ifunc_decl = decl_v->ifunc_decl;
+
+ if (ifunc_decl == NULL)
+ ifunc_decl = decl_v->ifunc_decl = make_ifunc_func (decl);
+
+ ifunc_resolver_decl = make_ifunc_resolver_func (decl, ifunc_decl,
+ &empty_bb);
+
+ old_current_function_decl = current_function_decl;
+ push_cfun (DECL_STRUCT_FUNCTION (ifunc_resolver_decl));
+ current_function_decl = ifunc_resolver_decl;
+
+ fn_ver_vec = VEC_alloc (tree, heap, 2);
+ VEC_safe_push (tree, heap, fn_ver_vec, decl);
+
+ for (ix = 0; VEC_iterate (void_p, decl_v->versions, ix, ele); ++ix)
+ {
+ version_function *v = (version_function *) ele;
+ gcc_assert (v->decl != NULL);
+ /* Check for virtual functions here again, as by this time it should
+ have been determined if this function needs a vtable index or
+ not. This happens for methods in derived classes that override
+ virtual methods in base classes but are not explicitly marked as
+ virtual. */
+ if (DECL_VINDEX (v->decl))
+ error_at (DECL_SOURCE_LOCATION (v->decl),
+ "Virtual function versioning not supported\n");
+ if (!v->is_deleted)
+ VEC_safe_push (tree, heap, fn_ver_vec, v->decl);
+ }
+
+ gcc_assert (targetm.dispatch_version);
+ targetm.dispatch_version (ifunc_resolver_decl, fn_ver_vec, &empty_bb);
+ decl_v->ifunc_resolver_decl = ifunc_resolver_decl;
+
+ pop_cfun ();
+ current_function_decl = old_current_function_decl;
+ return ifunc_resolver_decl;
+}
+
+/* Main entry point to pass_dispatch_versions. For multi-versioned functions,
+ generate the dispatching code. */
+
+static unsigned int
+do_dispatch_versions (void)
+{
+ /* A new pass for generating dispatch code for multi-versioned functions.
+ Other forms of dispatch can be added when ifunc support is not available
+ like just calling the function directly after checking for target type.
+ Currently, dispatching is done through IFUNC. This pass will become
+ more meaningful when other dispatch mechanisms are added. */
+
+ /* Cloning a function to produce more versions will happen here when the
+ user requests that via the target attribute. For example,
+ int foo () __attribute__ ((target(("arch=core2"), ("arch=corei7"))));
+ means that the user wants the same body of foo to be versioned for core2
+ and corei7. In that case, this function will be cloned during this
+ pass. */
+
+ if (DECL_FUNCTION_VERSIONED (current_function_decl)
+ && is_default_function (current_function_decl))
+ {
+ tree decl = make_ifunc_resolver_for_version (current_function_decl);
+ if (dump_file && decl)
+ dump_function_to_file (decl, dump_file, TDF_BLOCKS);
+ }
+ return 0;
+}
+
+static bool
+gate_dispatch_versions (void)
+{
+ return true;
+}
+
+/* A pass to generate the dispatch code to execute the appropriate version
+ of a multi-versioned function at run-time. */
+
+struct gimple_opt_pass pass_dispatch_versions =
+{
+ {
+ GIMPLE_PASS,
+ "dispatch_multiversion_functions", /* name */
+ gate_dispatch_versions, /* gate */
+ do_dispatch_versions, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_MULTIVERSION_DISPATCH, /* tv_id */
+ PROP_cfg, /* properties_required */
+ PROP_cfg, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ 0 /* todo_flags_finish */
+ }
+};
===================================================================
@@ -0,0 +1,55 @@
+/* Function Multiversioning.
+ Copyright (C) 2012 Free Software Foundation, Inc.
+ Contributed by Sriraman Tallam (tmsriram@google.com)
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+/* This is the header file which provides the functions to keep track
+ of functions that are multi-versioned and to generate the dispatch
+ code to call the right version at run-time. */
+
+#ifndef GCC_MULTIVERSION_H
+#define GCC_MULTIVERION_H
+
+#include "tree.h"
+
+/* Mark DECL1 and DECL2 as function versions. */
+int group_function_versions (const tree decl1, const tree decl2);
+
+/* Mark DECL as deleted and no longer a version. */
+void mark_delete_decl_version (const tree decl);
+
+/* Returns true if DECL is the default version to be executed if all
+ other versions are inappropriate at run-time. */
+bool is_default_function (const tree decl);
+
+/* Gets the IFUNC dispatcher for this multi-versioned function DECL. DECL
+ must be the default function in the multi-versioned group. */
+tree get_ifunc_for_version (const tree decl);
+
+/* Returns true when only one of DECL1 and DECL2 is marked with "target"
+ or if the "target" attribute strings of DECL1 and DECL2 dont match. */
+bool has_different_version_attributes (const tree decl1, const tree decl2);
+
+/* Function DECL is marked to be a multi-versioned function. If DECL is
+ not the default version, the assembler name of DECL is changed to include
+ the attribute string to keep the name unambiguous. */
+void mark_function_as_version (const tree decl);
+
+/* Check if decl is FUNCTION_DECL with target attribute set. */
+bool is_target_attribute_set (const tree decl);
+#endif
===================================================================
@@ -411,6 +411,13 @@ cgraph_finalize_function (tree decl, bool nested)
&& !DECL_DISREGARD_INLINE_LIMITS (decl))
node->symbol.force_output = 1;
+ /* With function versions, keep inline functions and do not worry about
+ inline limits. */
+ if (DECL_FUNCTION_VERSIONED (decl)
+ && DECL_DECLARED_INLINE_P (decl)
+ && !DECL_EXTERNAL (decl))
+ node->symbol.force_output = 1;
+
/* When not optimizing, also output the static functions. (see
PR24561), but don't do so for always_inline functions, functions
declared inline and nested functions. These were optimized out
===================================================================
@@ -0,0 +1,24 @@
+/* Simple test case to check if Multiversioning works. */
+/* { dg-do run } */
+/* { dg-options "-O2 -fdump-tree-dispatch_multiversion_functions" } */
+
+int foo ();
+int foo () __attribute__ ((target("arch=corei7")));
+
+int main ()
+{
+ int (*p)() = &foo;
+ return foo () + (*p)();
+}
+
+int foo ()
+{
+ return 0;
+}
+
+int __attribute__ ((target("arch=corei7")))
+foo ()
+{
+ return 0;
+}
+
===================================================================
@@ -38,6 +38,7 @@ along with GCC; see the file COPYING3. If not see
#include "tree-dump.h"
#include "splay-tree.h"
#include "pointer-set.h"
+#include "multiversion.h"
/* The number of nested classes being processed. If we are not in the
scope of any class, this is zero. */
@@ -1092,7 +1093,21 @@ add_method (tree type, tree method, tree using_dec
|| same_type_p (TREE_TYPE (fn_type),
TREE_TYPE (method_type))))
{
- if (using_decl)
+ /* For function versions, their parms and types match
+ but they are not duplicates. Record function versions
+ as and when they are found. */
+ if (TREE_CODE (fn) == FUNCTION_DECL
+ && TREE_CODE (method) == FUNCTION_DECL
+ && (is_target_attribute_set (fn)
+ || is_target_attribute_set (method))
+ && has_different_version_attributes (fn, method))
+ {
+ mark_function_as_version (fn);
+ mark_function_as_version (method);
+ group_function_versions (fn, method);
+ continue;
+ }
+ else if (using_decl)
{
if (DECL_CONTEXT (fn) == type)
/* Defer to the local function. */
@@ -1150,6 +1165,7 @@ add_method (tree type, tree method, tree using_dec
else
/* Replace the current slot. */
VEC_replace (tree, method_vec, slot, overload);
+
return true;
}
@@ -6930,8 +6946,11 @@ resolve_address_of_overloaded_function (tree targe
if (DECL_ANTICIPATED (fn))
continue;
- /* See if there's a match. */
- if (same_type_p (target_fn_type, static_fn_type (fn)))
+ /* See if there's a match. For functions that are multi-versioned
+ match it to the default function. */
+ if (same_type_p (target_fn_type, static_fn_type (fn))
+ && (!DECL_FUNCTION_VERSIONED (fn)
+ || is_default_function (fn)))
matches = tree_cons (fn, NULL_TREE, matches);
}
}
@@ -7093,6 +7112,21 @@ resolve_address_of_overloaded_function (tree targe
perform_or_defer_access_check (access_path, fn, fn);
}
+ /* If a pointer to a function that is multi-versioned is requested, the
+ pointer to the dispatcher function is returned instead. This works
+ well because indirectly calling the function will dispatch the right
+ function version at run-time. Also, the function address is kept
+ unique. */
+ if (DECL_FUNCTION_VERSIONED (fn)
+ && is_default_function (fn))
+ {
+ tree ifunc_decl;
+ ifunc_decl = get_ifunc_for_version (fn);
+ gcc_assert (ifunc_decl != NULL);
+ mark_used (fn);
+ return build_fold_addr_expr (ifunc_decl);
+ }
+
if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type))
return cp_build_addr_expr (fn, flags);
else
===================================================================
@@ -54,6 +54,7 @@ along with GCC; see the file COPYING3. If not see
#include "pointer-set.h"
#include "splay-tree.h"
#include "plugin.h"
+#include "multiversion.h"
/* Possible cases of bad specifiers type used by bad_specifiers. */
enum bad_spec_place {
@@ -973,6 +974,21 @@ decls_match (tree newdecl, tree olddecl)
if (t1 != t2)
return 0;
+ /* The decls dont match if they correspond to two different versions
+ of the same function. */
+ if (compparms (p1, p2)
+ && same_type_p (TREE_TYPE (f1), TREE_TYPE (f2))
+ && has_different_version_attributes (newdecl, olddecl))
+ {
+ /* One of the decls could be the default without the "target"
+ attribute. Set it to be a versioned function here. */
+ mark_function_as_version (newdecl);
+ mark_function_as_version (olddecl);
+ /* Accumulate all the versions of a function. */
+ group_function_versions (olddecl, newdecl);
+ return 0;
+ }
+
if (CP_DECL_CONTEXT (newdecl) != CP_DECL_CONTEXT (olddecl)
&& ! (DECL_EXTERN_C_P (newdecl)
&& DECL_EXTERN_C_P (olddecl)))
@@ -1490,7 +1506,11 @@ duplicate_decls (tree newdecl, tree olddecl, bool
error ("previous declaration %q+#D here", olddecl);
return NULL_TREE;
}
- else if (compparms (TYPE_ARG_TYPES (TREE_TYPE (newdecl)),
+ /* For function versions, params and types match, but they
+ are not ambiguous. */
+ else if ((!DECL_FUNCTION_VERSIONED (newdecl)
+ && !DECL_FUNCTION_VERSIONED (olddecl))
+ && compparms (TYPE_ARG_TYPES (TREE_TYPE (newdecl)),
TYPE_ARG_TYPES (TREE_TYPE (olddecl))))
{
error ("new declaration %q#D", newdecl);
@@ -2262,6 +2282,16 @@ duplicate_decls (tree newdecl, tree olddecl, bool
else if (DECL_PRESERVE_P (newdecl))
DECL_PRESERVE_P (olddecl) = 1;
+ /* If the olddecl is a version, so is the newdecl. */
+ if (TREE_CODE (newdecl) == FUNCTION_DECL
+ && DECL_FUNCTION_VERSIONED (olddecl))
+ {
+ DECL_FUNCTION_VERSIONED (newdecl) = 1;
+ /* Record that newdecl is not a valid version and has
+ been deleted. */
+ mark_delete_decl_version (newdecl);
+ }
+
if (TREE_CODE (newdecl) == FUNCTION_DECL)
{
int function_size;
@@ -14035,7 +14065,11 @@ cxx_comdat_group (tree decl)
else
break;
}
- name = DECL_ASSEMBLER_NAME (decl);
+ if (TREE_CODE (decl) == FUNCTION_DECL
+ && DECL_FUNCTION_VERSIONED (decl))
+ name = DECL_NAME (decl);
+ else
+ name = DECL_ASSEMBLER_NAME (decl);
}
return name;
===================================================================
@@ -3783,8 +3783,11 @@ expand_or_defer_fn_1 (tree fn)
/* If the user wants us to keep all inline functions, then mark
this function as needed so that finish_file will make sure to
output it later. Similarly, all dllexport'd functions must
- be emitted; there may be callers in other DLLs. */
- if ((flag_keep_inline_functions
+ be emitted; there may be callers in other DLLs.
+ Also, mark this function as needed if it is marked inline but
+ is a multi-versioned function. */
+ if (((flag_keep_inline_functions
+ || DECL_FUNCTION_VERSIONED (fn))
&& DECL_DECLARED_INLINE_P (fn)
&& !DECL_REALLY_EXTERN (fn))
|| (flag_keep_inline_dllexport
===================================================================
@@ -53,6 +53,7 @@ along with GCC; see the file COPYING3. If not see
#include "splay-tree.h"
#include "langhooks.h"
#include "c-family/c-ada-spec.h"
+#include "multiversion.h"
extern cpp_reader *parse_in;
@@ -677,9 +678,13 @@ check_classfn (tree ctype, tree function, tree tem
if (is_template != (TREE_CODE (fndecl) == TEMPLATE_DECL))
continue;
+ /* While finding a match, same types and params are not enough
+ if the function is versioned. Also check version ("target")
+ attributes. */
if (same_type_p (TREE_TYPE (TREE_TYPE (function)),
TREE_TYPE (TREE_TYPE (fndecl)))
&& compparms (p1, p2)
+ && !has_different_version_attributes (function, fndecl)
&& (!is_template
|| comp_template_parms (template_parms,
DECL_TEMPLATE_PARMS (fndecl)))
===================================================================
@@ -41,6 +41,7 @@ along with GCC; see the file COPYING3. If not see
#include "langhooks.h"
#include "c-family/c-objc.h"
#include "timevar.h"
+#include "multiversion.h"
/* The various kinds of conversion. */
@@ -3903,6 +3904,16 @@ build_new_function_call (tree fn, VEC(tree,gc) **a
{
if (complain & tf_error)
{
+ /* If the call is to a multiversioned function without
+ a default version, overload resolution will fail. */
+ if (candidates
+ && TREE_CODE (candidates->fn) == FUNCTION_DECL
+ && DECL_FUNCTION_VERSIONED (candidates->fn))
+ error_at (location_of (DECL_NAME (OVL_CURRENT (fn))),
+ "Call to multiversioned function %<%D(%A)%> with"
+ " no default version", DECL_NAME (OVL_CURRENT (fn)),
+ build_tree_list_vec (*args));
+
if (!any_viable_p && candidates && ! candidates->next
&& (TREE_CODE (candidates->fn) == FUNCTION_DECL))
return cp_build_function_call_vec (candidates->fn, args, complain);
@@ -6809,6 +6820,18 @@ build_over_call (struct z_candidate *cand, int fla
if (!already_used)
mark_used (fn);
+ /* For a call to a multi-versioned function, the call should actually be to
+ the dispatcher. */
+ if (DECL_FUNCTION_VERSIONED (fn)
+ && is_default_function (fn))
+ {
+ tree ifunc_decl;
+ ifunc_decl = get_ifunc_for_version (fn);
+ gcc_assert (ifunc_decl != NULL);
+ return build_call_expr_loc_array (UNKNOWN_LOCATION, ifunc_decl,
+ nargs, argarray);
+ }
+
if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0)
{
tree t;
@@ -8067,6 +8090,60 @@ joust (struct z_candidate *cand1, struct z_candida
size_t i;
size_t len;
+ /* For Candidates of a multi-versioned function, first check if the
+ target flags of the caller match any of the candidates. If so,
+ the caller can directly call this candidate otherwise the one marked
+ default wins. This is because the default decl is used as key to
+ aggregate all the other versions provided for it in multiversion.c.
+ When generating the actual call, the appropriate dispatcher is created
+ to call the right function version at run-time. */
+
+ if ((TREE_CODE (cand1->fn) == FUNCTION_DECL
+ && DECL_FUNCTION_VERSIONED (cand1->fn))
+ ||(TREE_CODE (cand2->fn) == FUNCTION_DECL
+ && DECL_FUNCTION_VERSIONED (cand2->fn)))
+ {
+ /* Both functions must be marked versioned. */
+ gcc_assert (DECL_FUNCTION_VERSIONED (cand1->fn)
+ && DECL_FUNCTION_VERSIONED (cand2->fn));
+
+ /* Try to see if a direct call can be made to a version. This is
+ possible if the caller and callee have the same target flags.
+ If cand->fn is marked with target attributes, check if the
+ target approves inlining this into the caller. If so, this is
+ the version we want. */
+
+ if (is_target_attribute_set (cand1->fn)
+ && targetm.target_option.can_inline_p (current_function_decl,
+ cand1->fn))
+ return 1;
+
+ if (is_target_attribute_set (cand2->fn)
+ && targetm.target_option.can_inline_p (current_function_decl,
+ cand2->fn))
+ return -1;
+
+ /* A direct call to a version is not possible, so find the default
+ function and return it. This will later be converted to dispatch
+ the right version at run time. */
+
+ if (is_default_function (cand1->fn))
+ {
+ mark_used (cand2->fn);
+ return 1;
+ }
+
+ if (is_default_function (cand2->fn))
+ {
+ mark_used (cand1->fn);
+ return -1;
+ }
+
+ /* If a default function is absent, this will never get resolved leading
+ to an ambiguous call error. */
+ return 0;
+ }
+
/* Candidates that involve bad conversions are always worse than those
that don't. */
if (cand1->viable > cand2->viable)
===================================================================
@@ -253,6 +253,7 @@ DEFTIMEVAR (TV_TREE_IFCOMBINE , "tree if-co
DEFTIMEVAR (TV_TREE_UNINIT , "uninit var analysis")
DEFTIMEVAR (TV_PLUGIN_INIT , "plugin initialization")
DEFTIMEVAR (TV_PLUGIN_RUN , "plugin execution")
+DEFTIMEVAR (TV_MULTIVERSION_DISPATCH , "multiversion dispatch")
/* Everything else in rest_of_compilation not included above. */
DEFTIMEVAR (TV_EARLY_LOCAL , "early local passes")
===================================================================
@@ -1294,6 +1294,7 @@ OBJS = \
mcf.o \
mode-switching.o \
modulo-sched.o \
+ multiversion.o \
omega.o \
omp-low.o \
optabs.o \
@@ -3030,6 +3031,11 @@ ree.o : ree.c $(CONFIG_H) $(SYSTEM_H) coretypes.h
$(DF_H) $(TIMEVAR_H) tree-pass.h $(RECOG_H) $(EXPR_H) \
$(REGS_H) $(TREE_H) $(TM_P_H) insn-config.h $(INSN_ATTR_H) $(DIAGNOSTIC_CORE_H) \
$(TARGET_H) $(OPTABS_H) insn-codes.h rtlhooks-def.h $(PARAMS_H) $(CGRAPH_H)
+multiversion.o : multiversion.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) \
+ $(TREE_H) langhooks.h $(TREE_INLINE_H) $(FLAGS_H) $(CGRAPH_H) intl.h \
+ $(DIAGNOSTIC_H) $(FIBHEAP_H) $(PARAMS_H) $(TIMEVAR_H) tree-pass.h \
+ $(HASHTAB_H) $(COVERAGE_H) $(GGC_H) $(TREE_FLOW_H) $(RTL_H) $(IPA_PROP_H) \
+ $(BASIC_BLOCK_H) $(TOPLEV_H) $(TREE_DUMP_H) ipa-inline.h
cprop.o : cprop.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) \
$(REGS_H) hard-reg-set.h $(FLAGS_H) insn-config.h $(GGC_H) \
$(RECOG_H) $(EXPR_H) $(BASIC_BLOCK_H) $(FUNCTION_H) output.h toplev.h $(DIAGNOSTIC_CORE_H) \
===================================================================
@@ -1287,6 +1287,7 @@ init_optimization_passes (void)
NEXT_PASS (pass_build_cfg);
NEXT_PASS (pass_warn_function_return);
NEXT_PASS (pass_build_cgraph_edges);
+ NEXT_PASS (pass_dispatch_versions);
*p = NULL;
/* Interprocedural optimization passes. */
===================================================================
@@ -27678,6 +27678,324 @@ ix86_init_mmx_sse_builtins (void)
}
}
+
+/* This adds a condition to the basic_block NEW_BB in function FUNCTION_DECL
+ to return a pointer to VERSION_DECL if the outcome of the expression
+ formed by PREDICATE_CHAIN is true. This function will be called during
+ version dispatch to decide which function version to execute. It returns
+ the basic block at the end to which more conditions can be added. */
+
+static basic_block
+add_condition_to_bb (tree function_decl, tree version_decl,
+ tree predicate_chain, basic_block new_bb)
+{
+ gimple return_stmt;
+ tree convert_expr, result_var;
+ gimple convert_stmt;
+ gimple call_cond_stmt;
+ gimple if_else_stmt;
+
+ basic_block bb1, bb2, bb3;
+ edge e12, e23;
+
+ tree cond_var, and_expr_var = NULL_TREE;
+ gimple_seq gseq;
+
+ tree old_current_function_decl;
+ tree predicate_decl, predicate_arg;
+
+ old_current_function_decl = current_function_decl;
+ push_cfun (DECL_STRUCT_FUNCTION (function_decl));
+ current_function_decl = function_decl;
+
+ gcc_assert (new_bb != NULL);
+ gseq = bb_seq (new_bb);
+
+
+ convert_expr = build1 (CONVERT_EXPR, ptr_type_node,
+ build_fold_addr_expr (version_decl));
+ result_var = create_tmp_var (ptr_type_node, NULL);
+ convert_stmt = gimple_build_assign (result_var, convert_expr);
+ return_stmt = gimple_build_return (result_var);
+
+ if (predicate_chain == NULL_TREE)
+ {
+ gimple_seq_add_stmt (&gseq, convert_stmt);
+ gimple_seq_add_stmt (&gseq, return_stmt);
+ set_bb_seq (new_bb, gseq);
+ gimple_set_bb (convert_stmt, new_bb);
+ gimple_set_bb (return_stmt, new_bb);
+ pop_cfun ();
+ current_function_decl = old_current_function_decl;
+ return new_bb;
+ }
+
+ while (predicate_chain != NULL)
+ {
+ cond_var = create_tmp_var (integer_type_node, NULL);
+ predicate_decl = TREE_PURPOSE (predicate_chain);
+ predicate_arg = TREE_VALUE (predicate_chain);
+ call_cond_stmt = gimple_build_call (predicate_decl, 1, predicate_arg);
+ gimple_call_set_lhs (call_cond_stmt, cond_var);
+
+ gimple_set_block (call_cond_stmt, DECL_INITIAL (function_decl));
+ gimple_set_bb (call_cond_stmt, new_bb);
+ gimple_seq_add_stmt (&gseq, call_cond_stmt);
+
+ predicate_chain = TREE_CHAIN (predicate_chain);
+
+ if (and_expr_var == NULL)
+ and_expr_var = cond_var;
+ else
+ {
+ gimple assign_stmt;
+ assign_stmt = gimple_build_assign_with_ops (BIT_AND_EXPR,
+ and_expr_var,
+ cond_var, and_expr_var);
+
+ gimple_set_block (assign_stmt, DECL_INITIAL (function_decl));
+ gimple_set_bb (assign_stmt, new_bb);
+ gimple_seq_add_stmt (&gseq, assign_stmt);
+ }
+ }
+
+ if_else_stmt = gimple_build_cond (GT_EXPR, and_expr_var,
+ integer_zero_node,
+ NULL_TREE, NULL_TREE);
+ gimple_set_block (if_else_stmt, DECL_INITIAL (function_decl));
+ gimple_set_bb (if_else_stmt, new_bb);
+ gimple_seq_add_stmt (&gseq, if_else_stmt);
+
+ gimple_seq_add_stmt (&gseq, convert_stmt);
+ gimple_seq_add_stmt (&gseq, return_stmt);
+ set_bb_seq (new_bb, gseq);
+
+ bb1 = new_bb;
+ e12 = split_block (bb1, if_else_stmt);
+ bb2 = e12->dest;
+ e12->flags &= ~EDGE_FALLTHRU;
+ e12->flags |= EDGE_TRUE_VALUE;
+
+ e23 = split_block (bb2, return_stmt);
+
+ gimple_set_bb (convert_stmt, bb2);
+ gimple_set_bb (return_stmt, bb2);
+
+ bb3 = e23->dest;
+ make_edge (bb1, bb3, EDGE_FALSE_VALUE);
+
+ remove_edge (e23);
+ make_edge (bb2, EXIT_BLOCK_PTR, 0);
+
+ rebuild_cgraph_edges ();
+
+ pop_cfun ();
+ current_function_decl = old_current_function_decl;
+
+ return bb3;
+}
+
+/* This parses the attribute arguments to target in DECL and determines
+ the right builtin to use to match the platform specification.
+ For now, only one target argument ("arch=" or "<-m>xxx") is allowed. */
+
+static tree
+get_builtin_code_for_version (tree decl)
+{
+ tree attrs;
+ struct cl_target_option cur_target;
+ tree target_node;
+ struct cl_target_option *new_target;
+ const char *arg_str = NULL;
+ const char *attrs_str = NULL;
+ char *tok_str = NULL;
+ char *token;
+ /* These are the target attribute strings for which a dispatcher is
+ available, from fold_builtin_cpu. */
+ const char *feature_list[] = {"mmx", "popcnt", "sse", "sse2", "sse3",
+ "ssse3", "sse4.1", "sse4.2", "avx", "avx2"};
+ unsigned int NUM_FEATURES = sizeof (feature_list) / sizeof (const char *);
+ unsigned int i;
+ tree predicate_chain = NULL_TREE;
+ tree predicate_decl, predicate_arg;
+
+ attrs = lookup_attribute ("target", DECL_ATTRIBUTES (decl));
+ gcc_assert (attrs != NULL);
+
+ attrs = TREE_VALUE (TREE_VALUE (attrs));
+
+ gcc_assert (TREE_CODE (attrs) == STRING_CST);
+ attrs_str = TREE_STRING_POINTER (attrs);
+
+ /* Handle arch= if specified. */
+ if (strstr (attrs_str, "arch=") != NULL)
+ {
+ cl_target_option_save (&cur_target, &global_options);
+ target_node = ix86_valid_target_attribute_tree (attrs);
+
+ gcc_assert (target_node);
+ new_target = TREE_TARGET_OPTION (target_node);
+ gcc_assert (new_target);
+
+ if (new_target->arch_specified && new_target->arch > 0)
+ {
+ switch (new_target->arch)
+ {
+ case PROCESSOR_CORE2_32:
+ case PROCESSOR_CORE2_64:
+ arg_str = "core2";
+ break;
+ case PROCESSOR_COREI7_32:
+ case PROCESSOR_COREI7_64:
+ arg_str = "corei7";
+ break;
+ case PROCESSOR_ATOM:
+ arg_str = "atom";
+ break;
+ case PROCESSOR_AMDFAM10:
+ arg_str = "amdfam10h";
+ break;
+ case PROCESSOR_BDVER1:
+ arg_str = "bdver1";
+ break;
+ case PROCESSOR_BDVER2:
+ arg_str = "bdver2";
+ break;
+ }
+ }
+
+ cl_target_option_restore (&global_options, &cur_target);
+ if (arg_str == NULL)
+ {
+ error_at (DECL_SOURCE_LOCATION (decl),
+ "No dispatcher found for the versioning attributes");
+ return NULL;
+ }
+
+ predicate_decl = ix86_builtins [(int) IX86_BUILTIN_CPU_IS];
+ /* For a C string literal the length includes the trailing NULL. */
+ predicate_arg = build_string_literal (strlen (arg_str) + 1, arg_str);
+ predicate_chain = tree_cons (predicate_decl, predicate_arg,
+ predicate_chain);
+ }
+
+ /* Process feature name. */
+ tok_str = (char *) xmalloc (strlen (attrs_str) + 1);
+ strcpy (tok_str, attrs_str);
+ token = strtok (tok_str, ",");
+ predicate_decl = ix86_builtins [(int) IX86_BUILTIN_CPU_SUPPORTS];
+
+ while (token != NULL)
+ {
+ /* Do not process "arch=" */
+ if (strncmp (token, "arch=", 5) == 0)
+ {
+ token = strtok (NULL, ",");
+ continue;
+ }
+ for (i = 0; i < NUM_FEATURES; ++i)
+ {
+ if (strcmp (token, feature_list[i]) == 0)
+ {
+ predicate_arg = build_string_literal (
+ strlen (feature_list[i]) + 1,
+ feature_list[i]);
+ predicate_chain = tree_cons (predicate_decl, predicate_arg,
+ predicate_chain);
+ break;
+ }
+ }
+ if (i == NUM_FEATURES)
+ {
+ error_at (DECL_SOURCE_LOCATION (decl),
+ "No dispatcher found for %s", token);
+ return NULL;
+ }
+ token = strtok (NULL, ",");
+ }
+ free (tok_str);
+
+ if (predicate_chain == NULL_TREE)
+ {
+ error_at (DECL_SOURCE_LOCATION (decl),
+ "No dispatcher found for the versioning attributes : %s",
+ attrs_str);
+ return NULL;
+ }
+
+ predicate_chain = nreverse (predicate_chain);
+ return predicate_chain;
+}
+
+/* This is the target hook to generate the dispatch function for
+ multi-versioned functions. DISPATCH_DECL is the function which will
+ contain the dispatch logic. FNDECLS are the function choices for
+ dispatch, and is a tree chain. EMPTY_BB is the basic block pointer
+ in DISPATCH_DECL in which the dispatch code is generated. */
+
+static int
+ix86_dispatch_version (tree dispatch_decl,
+ void *fndecls_p,
+ basic_block *empty_bb)
+{
+ tree default_decl;
+ gimple ifunc_cpu_init_stmt;
+ gimple_seq gseq;
+ tree old_current_function_decl;
+ int ix;
+ tree ele;
+ VEC (tree, heap) *fndecls;
+
+ gcc_assert (dispatch_decl != NULL
+ && fndecls_p != NULL
+ && empty_bb != NULL);
+
+ /*fndecls_p is actually a vector. */
+ fndecls = (VEC (tree, heap) *)fndecls_p;
+
+ /* Atleast one more version other than the default. */
+ gcc_assert (VEC_length (tree, fndecls) >= 2);
+
+ /* The first version in the vector is the default decl. */
+ default_decl = VEC_index (tree, fndecls, 0);
+
+ old_current_function_decl = current_function_decl;
+ push_cfun (DECL_STRUCT_FUNCTION (dispatch_decl));
+ current_function_decl = dispatch_decl;
+
+ gseq = bb_seq (*empty_bb);
+ ifunc_cpu_init_stmt = gimple_build_call_vec (
+ ix86_builtins [(int) IX86_BUILTIN_CPU_INIT], NULL);
+ gimple_seq_add_stmt (&gseq, ifunc_cpu_init_stmt);
+ gimple_set_bb (ifunc_cpu_init_stmt, *empty_bb);
+ set_bb_seq (*empty_bb, gseq);
+
+ pop_cfun ();
+ current_function_decl = old_current_function_decl;
+
+
+ for (ix = 1; VEC_iterate (tree, fndecls, ix, ele); ++ix)
+ {
+ tree version_decl = ele;
+ tree predicate_chain = NULL_TREE;
+ /* Get attribute string, parse it and find the right predicate decl.
+ The predicate function could be a lengthy combination of many
+ features, like arch-type and various isa-variants. */
+ predicate_chain = get_builtin_code_for_version (version_decl);
+
+ if (predicate_chain == NULL_TREE)
+ continue;
+
+ *empty_bb = add_condition_to_bb (dispatch_decl, version_decl,
+ predicate_chain, *empty_bb);
+
+ }
+ /* dispatch default version at the end. */
+ *empty_bb = add_condition_to_bb (dispatch_decl, default_decl,
+ NULL, *empty_bb);
+ return 0;
+}
+
/* This builds the processor_model struct type defined in
libgcc/config/i386/i386-cpuinfo.c */
@@ -39463,6 +39781,9 @@ ix86_autovectorize_vector_sizes (void)
#undef TARGET_FOLD_BUILTIN
#define TARGET_FOLD_BUILTIN ix86_fold_builtin
+#undef TARGET_DISPATCH_VERSION
+#define TARGET_DISPATCH_VERSION ix86_dispatch_version
+
#undef TARGET_ENUM_VA_LIST_P
#define TARGET_ENUM_VA_LIST_P ix86_enum_va_list