modified_flags are defined in ipa_node_params structure
(defined in ipa_prop.h and pointed to by cgraph_edge->aux).
- -ipcp_init_stage() is the first stage driver.
+ -ipcp_generate_summary() is the first stage driver.
Second stage - interprocedural analysis
========================================
-ipcp_insert_stage() is the third phase driver.
+
+ This pass also performs devirtualization - turns virtual calls into direct
+ ones if it can prove that all invocations of the function call the same
+ callee. This is achieved by building a list of all base types (actually,
+ their BINFOs) that individual parameters can have in an iterative matter
+ just like propagating scalar constants and then examining whether virtual
+ calls which take a parameter as their object fold to the same target for all
+ these types. If we cannot enumerate all types or there is a type which does
+ not have any BINFO associated with it, cannot_devirtualize of the associated
+ parameter descriptor is set which is an equivalent of BOTTOM lattice value
+ in standard IPA constant propagation.
*/
#include "config.h"
#include "coretypes.h"
#include "tree.h"
#include "target.h"
+#include "gimple.h"
#include "cgraph.h"
#include "ipa-prop.h"
#include "tree-flow.h"
print_generic_expr (f, DECL_INITIAL (TREE_OPERAND (cst, 0)),
0);
}
- fprintf (f, "\n");
}
else if (lat->type == IPA_TOP)
- fprintf (f, "type is TOP\n");
+ fprintf (f, "type is TOP");
+ else
+ fprintf (f, "type is BOTTOM");
+ if (ipa_param_cannot_devirtualize_p (info, i))
+ fprintf (f, " - cannot_devirtualize set\n");
+ else if (ipa_param_types_vec_empty (info, i))
+ fprintf (f, " - type list empty\n");
else
- fprintf (f, "type is BOTTOM\n");
+ fprintf (f, "\n");
}
}
}
return true;
}
+/* Mark parameter with index I of function described by INFO as unsuitable for
+ devirtualization. Return true if it has already been marked so. */
+
+static bool
+ipa_set_param_cannot_devirtualize (struct ipa_node_params *info, int i)
+{
+ bool ret = info->params[i].cannot_devirtualize;
+ info->params[i].cannot_devirtualize = true;
+ if (info->params[i].types)
+ VEC_free (tree, heap, info->params[i].types);
+ return ret;
+}
+
/* Initialize ipcp_lattices array. The lattices corresponding to supported
types (integers, real types and Fortran constants defined as const_decls)
are initialized to IPA_TOP, the rest of them to IPA_BOTTOM. */
type = IPA_BOTTOM;
for (i = 0; i < ipa_get_param_count (info) ; i++)
- ipcp_get_lattice (info, i)->type = type;
+ {
+ ipcp_get_lattice (info, i)->type = type;
+ if (type == IPA_BOTTOM)
+ ipa_set_param_cannot_devirtualize (info, i);
+ }
}
/* build INTEGER_CST tree with type TREE_TYPE and value according to LAT.
ipcp_set_node_scale (node, sum * REG_BR_PROB_BASE / node->count);
}
-/* Initialization and computation of IPCP data structures. This is the initial
- intraprocedural analysis of functions, which gathers information to be
- propagated later on. */
-
-static void
-ipcp_init_stage (void)
-{
- struct cgraph_node *node;
-
- for (node = cgraph_nodes; node; node = node->next)
- if (node->analyzed)
- {
- /* Unreachable nodes should have been eliminated before ipcp. */
- gcc_assert (node->needed || node->reachable);
-
- node->local.versionable = tree_versionable_function_p (node->decl);
- ipa_analyze_node (node);
- }
-}
-
/* Return true if there are some formal parameters whose value is IPA_TOP (in
the whole compilation unit). Change their values to IPA_BOTTOM, since they
most probably get their values from outside of this compilation unit. */
}
lat->type = IPA_BOTTOM;
}
+ if (!ipa_param_cannot_devirtualize_p (info, i)
+ && ipa_param_types_vec_empty (info, i))
+ {
+ prop_again = true;
+ ipa_set_param_cannot_devirtualize (info, i);
+ if (dump_file)
+ {
+ fprintf (dump_file, "Marking param ");
+ print_generic_expr (dump_file, ipa_get_param (info, i), 0);
+ fprintf (dump_file, " of node %s as unusable for "
+ "devirtualization.\n",
+ cgraph_node_name (node));
+ }
+ }
}
}
return prop_again;
}
+/* Insert BINFO to the list of known types of parameter number I of the
+ function described by CALLEE_INFO. Return true iff the type information
+ associated with the callee parameter changed in any way. */
+
+static bool
+ipcp_add_param_type (struct ipa_node_params *callee_info, int i, tree binfo)
+{
+ int j, count;
+
+ if (ipa_param_cannot_devirtualize_p (callee_info, i))
+ return false;
+
+ if (callee_info->params[i].types)
+ {
+ count = VEC_length (tree, callee_info->params[i].types);
+ for (j = 0; j < count; j++)
+ if (VEC_index (tree, callee_info->params[i].types, j) == binfo)
+ return false;
+ }
+
+ if (VEC_length (tree, callee_info->params[i].types)
+ == (unsigned) PARAM_VALUE (PARAM_DEVIRT_TYPE_LIST_SIZE))
+ return !ipa_set_param_cannot_devirtualize (callee_info, i);
+
+ VEC_safe_push (tree, heap, callee_info->params[i].types, binfo);
+ return true;
+}
+
+/* Copy known types information for parameter number CALLEE_IDX of CALLEE_INFO
+ from a parameter of CALLER_INFO as described by JF. Return true iff the
+ type information changed in any way. JF must be a pass-through or an
+ ancestor jump function. */
+
+static bool
+ipcp_copy_types (struct ipa_node_params *caller_info,
+ struct ipa_node_params *callee_info,
+ int callee_idx, struct ipa_jump_func *jf)
+{
+ int caller_idx, j, count;
+ bool res;
+
+ if (ipa_param_cannot_devirtualize_p (callee_info, callee_idx))
+ return false;
+
+ if (jf->type == IPA_JF_PASS_THROUGH)
+ {
+ if (jf->value.pass_through.operation != NOP_EXPR)
+ {
+ ipa_set_param_cannot_devirtualize (callee_info, callee_idx);
+ return true;
+ }
+ caller_idx = jf->value.pass_through.formal_id;
+ }
+ else
+ caller_idx = jf->value.ancestor.formal_id;
+
+ if (ipa_param_cannot_devirtualize_p (caller_info, caller_idx))
+ {
+ ipa_set_param_cannot_devirtualize (callee_info, callee_idx);
+ return true;
+ }
+
+ if (!caller_info->params[caller_idx].types)
+ return false;
+
+ res = false;
+ count = VEC_length (tree, caller_info->params[caller_idx].types);
+ for (j = 0; j < count; j++)
+ {
+ tree binfo = VEC_index (tree, caller_info->params[caller_idx].types, j);
+ if (jf->type == IPA_JF_ANCESTOR)
+ {
+ binfo = get_binfo_at_offset (binfo, jf->value.ancestor.offset,
+ jf->value.ancestor.type);
+ if (!binfo)
+ {
+ ipa_set_param_cannot_devirtualize (callee_info, callee_idx);
+ return true;
+ }
+ }
+ res |= ipcp_add_param_type (callee_info, callee_idx, binfo);
+ }
+ return res;
+}
+
+/* Propagate type information for parameter of CALLEE_INFO number I as
+ described by JF. CALLER_INFO describes the caller. Return true iff the
+ type information changed in any way. */
+
+static bool
+ipcp_propagate_types (struct ipa_node_params *caller_info,
+ struct ipa_node_params *callee_info,
+ struct ipa_jump_func *jf, int i)
+{
+ tree cst, binfo;
+
+ switch (jf->type)
+ {
+ case IPA_JF_UNKNOWN:
+ case IPA_JF_CONST_MEMBER_PTR:
+ break;
+
+ case IPA_JF_KNOWN_TYPE:
+ return ipcp_add_param_type (callee_info, i, jf->value.base_binfo);
+
+ case IPA_JF_CONST:
+ cst = jf->value.constant;
+ if (TREE_CODE (cst) != ADDR_EXPR)
+ break;
+ binfo = gimple_get_relevant_ref_binfo (TREE_OPERAND (cst, 0), NULL_TREE);
+ if (!binfo)
+ break;
+ return ipcp_add_param_type (callee_info, i, binfo);
+
+ case IPA_JF_PASS_THROUGH:
+ case IPA_JF_ANCESTOR:
+ return ipcp_copy_types (caller_info, callee_info, i, jf);
+ }
+
+ /* If we reach this we cannot use this parameter for devirtualization. */
+ return !ipa_set_param_cannot_devirtualize (callee_info, i);
+}
+
/* Interprocedural analysis. The algorithm propagates constants from the
caller's parameters to the callee's arguments. */
static void
dest_lat->constant = new_lat.constant;
ipa_push_func_to_list (&wl, cs->callee);
}
+
+ if (ipcp_propagate_types (info, callee_info, jump_func, i))
+ ipa_push_func_to_list (&wl, cs->callee);
}
}
}
{
struct ipa_node_params *orig_callee_info;
int i, count;
- struct ipa_jump_func *jump_func;
struct cgraph_node *node = cs->callee, *orig;
if (!n_cloning_candidates)
for (i = 0; i < count; i++)
{
struct ipcp_lattice *lat = ipcp_get_lattice (orig_callee_info, i);
- if (ipcp_lat_is_const (lat))
- {
- jump_func = ipa_get_ith_jump_func (IPA_EDGE_REF (cs), i);
- if (jump_func->type != IPA_JF_CONST)
- return true;
- }
+ struct ipa_jump_func *jump_func;
+
+ jump_func = ipa_get_ith_jump_func (IPA_EDGE_REF (cs), i);
+ if ((ipcp_lat_is_const (lat)
+ && jump_func->type != IPA_JF_CONST)
+ || (!ipa_param_cannot_devirtualize_p (orig_callee_info, i)
+ && !ipa_param_types_vec_empty (orig_callee_info, i)
+ && jump_func->type != IPA_JF_CONST
+ && jump_func->type != IPA_JF_KNOWN_TYPE))
+ return true;
}
return false;
{
next = cs->next_caller;
if (!ipcp_node_is_clone (cs->caller) && ipcp_need_redirect_p (cs))
- cgraph_redirect_edge_callee (cs, orig_node);
+ {
+ if (dump_file)
+ fprintf (dump_file, "Redirecting edge %s/%i -> %s/%i "
+ "back to %s/%i.",
+ cgraph_node_name (cs->caller), cs->caller->uid,
+ cgraph_node_name (cs->callee), cs->callee->uid,
+ cgraph_node_name (orig_node), orig_node->uid);
+ cgraph_redirect_edge_callee (cs, orig_node);
+ }
}
}
}
return cost + 1;
}
+/* Walk indirect calls of NODE and if any polymorphic can be turned into a
+ direct one now, do so. */
+
+static void
+ipcp_process_devirtualization_opportunities (struct cgraph_node *node)
+{
+ struct ipa_node_params *info = IPA_NODE_REF (node);
+ struct cgraph_edge *ie, *next_ie;
+
+ for (ie = node->indirect_calls; ie; ie = next_ie)
+ {
+ int param_index, types_count, j;
+ HOST_WIDE_INT token;
+ tree target;
+
+ next_ie = ie->next_callee;
+ if (!ie->indirect_info->polymorphic)
+ continue;
+ param_index = ie->indirect_info->param_index;
+ if (param_index == -1
+ || ipa_param_cannot_devirtualize_p (info, param_index)
+ || ipa_param_types_vec_empty (info, param_index))
+ continue;
+
+ token = ie->indirect_info->otr_token;
+ target = NULL_TREE;
+ types_count = VEC_length (tree, info->params[param_index].types);
+ for (j = 0; j < types_count; j++)
+ {
+ tree binfo = VEC_index (tree, info->params[param_index].types, j);
+ tree t = gimple_fold_obj_type_ref_known_binfo (token, binfo);
+
+ if (!t)
+ {
+ target = NULL_TREE;
+ break;
+ }
+ else if (!target)
+ target = t;
+ else if (target != t)
+ {
+ target = NULL_TREE;
+ break;
+ }
+ }
+
+ if (target)
+ ipa_make_edge_direct_to_target (ie, target);
+ }
+}
+
/* Return number of live constant parameters. */
static int
ipcp_const_param_count (struct cgraph_node *node)
for (i = 0; i < count; i++)
{
struct ipcp_lattice *lat = ipcp_get_lattice (info, i);
- if (ipcp_lat_is_insertable (lat)
+ if ((ipcp_lat_is_insertable (lat)
/* Do not count obviously unused arguments. */
- && ipa_is_param_used (info, i))
+ && ipa_is_param_used (info, i))
+ || (!ipa_param_cannot_devirtualize_p (info, i)
+ && !ipa_param_types_vec_empty (info, i)))
const_param++;
}
return const_param;
max_new_size = PARAM_VALUE (PARAM_LARGE_UNIT_INSNS);
max_new_size = max_new_size * PARAM_VALUE (PARAM_IPCP_UNIT_GROWTH) / 100 + 1;
- /* First collect all functions we proved to have constant arguments to heap. */
+ /* First collect all functions we proved to have constant arguments to
+ heap. */
heap = fibheap_new ();
for (node = cgraph_nodes; node; node = node->next)
{
if (ipa_is_called_with_var_arguments (info))
continue;
if (ipcp_const_param_count (node))
- node->aux = fibheap_insert (heap, ipcp_estimate_cloning_cost (node), node);
+ node->aux = fibheap_insert (heap, ipcp_estimate_cloning_cost (node),
+ node);
}
/* Now clone in priority order until code size growth limits are met or
if (node1 == NULL)
continue;
+ ipcp_process_devirtualization_opportunities (node1);
+
if (dump_file)
fprintf (dump_file, "versioned function %s with growth %i, overall %i\n",
cgraph_node_name (node), (int)growth, (int)new_size);
return 0;
}
-/* Note function body size. */
+/* Initialization and computation of IPCP data structures. This is the initial
+ intraprocedural analysis of functions, which gathers information to be
+ propagated later on. */
+
static void
ipcp_generate_summary (void)
{
+ struct cgraph_node *node;
+
if (dump_file)
fprintf (dump_file, "\nIPA constant propagation start:\n");
ipa_check_create_node_params ();
ipa_check_create_edge_args ();
ipa_register_cgraph_hooks ();
- /* 1. Call the init stage to initialize
- the ipa_node_params and ipa_edge_args structures. */
- ipcp_init_stage ();
+
+ for (node = cgraph_nodes; node; node = node->next)
+ if (node->analyzed)
+ {
+ /* Unreachable nodes should have been eliminated before ipcp. */
+ gcc_assert (node->needed || node->reachable);
+
+ node->local.versionable = tree_versionable_function_p (node->decl);
+ ipa_analyze_node (node);
+ }
}
/* Write ipcp summary for nodes in SET. */
projects / thirdparty / gcc.git / commitdiff
