--- /dev/null
+/* Interprocedural constant propagation
+ Copyright (C) 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+ Contributed by Razya Ladelsky <RAZYA@il.ibm.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/>. */
+
+/* Interprocedural constant propagation. The aim of interprocedural constant
+ propagation (IPCP) is to find which function's argument has the same
+ constant value in each invocation throughout the whole program. For example,
+ consider the following program:
+
+ int g (int y)
+ {
+ printf ("value is %d",y);
+ }
+
+ int f (int x)
+ {
+ g (x);
+ }
+
+ int h (int y)
+ {
+ g (y);
+ }
+
+ void main (void)
+ {
+ f (3);
+ h (3);
+ }
+
+
+ The IPCP algorithm will find that g's formal argument y is always called
+ with the value 3.
+
+ The algorithm used is based on "Interprocedural Constant Propagation", by
+ Challahan David, Keith D Cooper, Ken Kennedy, Linda Torczon, Comp86, pg
+ 152-161
+
+ The optimization is divided into three stages:
+
+ First stage - intraprocedural analysis
+ =======================================
+ This phase computes jump_function and modification flags.
+
+ A jump function for a callsite represents the values passed as an actual
+ arguments of a given callsite. There are three types of values:
+ Pass through - the caller's formal parameter is passed as an actual argument.
+ Constant - a constant is passed as an actual argument.
+ Unknown - neither of the above.
+
+ The jump function info, ipa_jump_func, is stored in ipa_edge_args
+ structure (defined in ipa_prop.h and pointed to by cgraph_node->aux)
+ 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.
+
+ Second stage - interprocedural analysis
+ ========================================
+ This phase does the interprocedural constant propagation.
+ It computes lattices for all formal parameters in the program
+ and their value that may be:
+ TOP - unknown.
+ BOTTOM - non constant.
+ CONSTANT - constant value.
+
+ Lattice describing a formal parameter p will have a constant value if all
+ callsites invoking this function have the same constant value passed to p.
+
+ The lattices are stored in ipcp_lattice which is itself in ipa_node_params
+ structure (defined in ipa_prop.h and pointed to by cgraph_edge->aux).
+
+ -ipcp_iterate_stage() is the second stage driver.
+
+ Third phase - transformation of function code
+ ============================================
+ Propagates the constant-valued formals into the function.
+ For each function whose parameters are constants, we create its clone.
+
+ Then we process the clone in two ways:
+ 1. We insert an assignment statement 'parameter = const' at the beginning
+ of the cloned function.
+ 2. For read-only parameters that do not live in memory, we replace all their
+ uses with the constant.
+
+ We also need to modify some callsites to call the cloned functions instead
+ of the original ones. For a callsite passing an argument found to be a
+ constant by IPCP, there are two different cases to handle:
+ 1. A constant is passed as an argument. In this case the callsite in the
+ should be redirected to call the cloned callee.
+ 2. A parameter (of the caller) passed as an argument (pass through
+ argument). In such cases both the caller and the callee have clones and
+ only the callsite in the cloned caller is redirected to call to the
+ cloned callee.
+
+ This update is done in two steps: First all cloned functions are created
+ during a traversal of the call graph, during which all callsites are
+ redirected to call the cloned function. Then the callsites are traversed
+ and many calls redirected back to fit the description above.
+
+ -ipcp_insert_stage() is the third phase driver.
+
+*/
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tree.h"
+#include "target.h"
+#include "cgraph.h"
+#include "ipa-prop.h"
+#include "tree-flow.h"
+#include "tree-pass.h"
+#include "flags.h"
+#include "timevar.h"
+#include "diagnostic.h"
+#include "tree-dump.h"
+#include "tree-inline.h"
+#include "fibheap.h"
+#include "params.h"
+
+/* Number of functions identified as candidates for cloning. When not cloning
+ we can simplify iterate stage not forcing it to go through the decision
+ on what is profitable and what not. */
+static int n_cloning_candidates;
+
+/* Maximal count found in program. */
+static gcov_type max_count;
+
+/* Cgraph nodes that has been completely replaced by cloning during iterate
+ * stage and will be removed after ipcp is finished. */
+static bitmap dead_nodes;
+
+static void ipcp_print_profile_data (FILE *);
+static void ipcp_function_scale_print (FILE *);
+
+/* Get the original node field of ipa_node_params associated with node NODE. */
+static inline struct cgraph_node *
+ipcp_get_orig_node (struct cgraph_node *node)
+{
+ return IPA_NODE_REF (node)->ipcp_orig_node;
+}
+
+/* Return true if NODE describes a cloned/versioned function. */
+static inline bool
+ipcp_node_is_clone (struct cgraph_node *node)
+{
+ return (ipcp_get_orig_node (node) != NULL);
+}
+
+/* Create ipa_node_params and its data structures for NEW_NODE. Set ORIG_NODE
+ as the ipcp_orig_node field in ipa_node_params. */
+static void
+ipcp_init_cloned_node (struct cgraph_node *orig_node,
+ struct cgraph_node *new_node)
+{
+ ipa_check_create_node_params ();
+ ipa_initialize_node_params (new_node);
+ IPA_NODE_REF (new_node)->ipcp_orig_node = orig_node;
+}
+
+/* Perform intraprocedrual analysis needed for ipcp. */
+static void
+ipcp_analyze_node (struct cgraph_node *node)
+{
+ /* Unreachable nodes should have been eliminated before ipcp. */
+ gcc_assert (node->needed || node->reachable);
+
+ ipa_initialize_node_params (node);
+ ipa_detect_param_modifications (node);
+}
+
+/* Recompute all local information since node might've got new
+ direct calls after cloning. */
+static void
+ipcp_update_cloned_node (struct cgraph_node *new_node)
+{
+ basic_block bb;
+ gimple_stmt_iterator gsi;
+
+ /* We might've introduced new direct calls. */
+ push_cfun (DECL_STRUCT_FUNCTION (new_node->decl));
+ current_function_decl = new_node->decl;
+
+ FOR_EACH_BB (bb)
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ tree decl;
+
+ if (is_gimple_call (stmt)
+ && (decl = gimple_call_fndecl (stmt))
+ && !cgraph_edge (new_node, stmt))
+ {
+ struct cgraph_edge *new_edge;
+
+ new_edge = cgraph_create_edge (new_node, cgraph_node (decl), stmt,
+ bb->count,
+ compute_call_stmt_bb_frequency (bb),
+ bb->loop_depth);
+ new_edge->indirect_call = 1;
+ }
+ }
+
+ /* Indirect inlinng rely on fact that we've already analyzed
+ the body.. */
+ if (flag_indirect_inlining)
+ {
+ struct cgraph_edge *cs;
+
+ ipcp_analyze_node (new_node);
+
+ for (cs = new_node->callees; cs; cs = cs->next_callee)
+ {
+ ipa_count_arguments (cs);
+ ipa_compute_jump_functions (cs);
+ }
+ }
+ pop_cfun ();
+ current_function_decl = NULL;
+}
+
+/* Return scale for NODE. */
+static inline gcov_type
+ipcp_get_node_scale (struct cgraph_node *node)
+{
+ return IPA_NODE_REF (node)->count_scale;
+}
+
+/* Set COUNT as scale for NODE. */
+static inline void
+ipcp_set_node_scale (struct cgraph_node *node, gcov_type count)
+{
+ IPA_NODE_REF (node)->count_scale = count;
+}
+
+/* Return whether LAT is a constant lattice. */
+static inline bool
+ipcp_lat_is_const (struct ipcp_lattice *lat)
+{
+ if (lat->type == IPA_CONST_VALUE)
+ return true;
+ else
+ return false;
+}
+
+/* Return whether LAT is a constant lattice that ipa-cp can actually insert
+ into the code (i.e. constants excluding member pointers and pointers). */
+static inline bool
+ipcp_lat_is_insertable (struct ipcp_lattice *lat)
+{
+ return lat->type == IPA_CONST_VALUE;
+}
+
+/* Return true if LAT1 and LAT2 are equal. */
+static inline bool
+ipcp_lats_are_equal (struct ipcp_lattice *lat1, struct ipcp_lattice *lat2)
+{
+ gcc_assert (ipcp_lat_is_const (lat1) && ipcp_lat_is_const (lat2));
+ if (lat1->type != lat2->type)
+ return false;
+
+ if (operand_equal_p (lat1->constant, lat2->constant, 0))
+ return true;
+
+ return false;
+}
+
+/* Compute Meet arithmetics:
+ Meet (IPA_BOTTOM, x) = IPA_BOTTOM
+ Meet (IPA_TOP,x) = x
+ Meet (const_a,const_b) = IPA_BOTTOM, if const_a != const_b.
+ MEET (const_a,const_b) = const_a, if const_a == const_b.*/
+static void
+ipa_lattice_meet (struct ipcp_lattice *res, struct ipcp_lattice *lat1,
+ struct ipcp_lattice *lat2)
+{
+ if (lat1->type == IPA_BOTTOM || lat2->type == IPA_BOTTOM)
+ {
+ res->type = IPA_BOTTOM;
+ return;
+ }
+ if (lat1->type == IPA_TOP)
+ {
+ res->type = lat2->type;
+ res->constant = lat2->constant;
+ return;
+ }
+ if (lat2->type == IPA_TOP)
+ {
+ res->type = lat1->type;
+ res->constant = lat1->constant;
+ return;
+ }
+ if (!ipcp_lats_are_equal (lat1, lat2))
+ {
+ res->type = IPA_BOTTOM;
+ return;
+ }
+ res->type = lat1->type;
+ res->constant = lat1->constant;
+}
+
+/* Return the lattice corresponding to the Ith formal parameter of the function
+ described by INFO. */
+static inline struct ipcp_lattice *
+ipcp_get_lattice (struct ipa_node_params *info, int i)
+{
+ return &(info->params[i].ipcp_lattice);
+}
+
+/* Given the jump function JFUNC, compute the lattice LAT that describes the
+ value coming down the callsite. INFO describes the caller node so that
+ pass-through jump functions can be evaluated. */
+static void
+ipcp_lattice_from_jfunc (struct ipa_node_params *info, struct ipcp_lattice *lat,
+ struct ipa_jump_func *jfunc)
+{
+ if (jfunc->type == IPA_CONST)
+ {
+ lat->type = IPA_CONST_VALUE;
+ lat->constant = jfunc->value.constant;
+ }
+ else if (jfunc->type == IPA_PASS_THROUGH)
+ {
+ struct ipcp_lattice *caller_lat;
+
+ caller_lat = ipcp_get_lattice (info, jfunc->value.formal_id);
+ lat->type = caller_lat->type;
+ lat->constant = caller_lat->constant;
+ }
+ else
+ lat->type = IPA_BOTTOM;
+}
+
+/* True when OLD_LAT and NEW_LAT values are not the same. */
+
+static bool
+ipcp_lattice_changed (struct ipcp_lattice *old_lat,
+ struct ipcp_lattice *new_lat)
+{
+ if (old_lat->type == new_lat->type)
+ {
+ if (!ipcp_lat_is_const (old_lat))
+ return false;
+ if (ipcp_lats_are_equal (old_lat, new_lat))
+ return false;
+ }
+ return true;
+}
+
+/* Print all ipcp_lattices of all functions to F. */
+static void
+ipcp_print_all_lattices (FILE * f)
+{
+ struct cgraph_node *node;
+ int i, count;
+
+ fprintf (f, "\nLattice:\n");
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ struct ipa_node_params *info;
+
+ if (!node->analyzed)
+ continue;
+ info = IPA_NODE_REF (node);
+ fprintf (f, " Node: %s:\n", cgraph_node_name (node));
+ count = ipa_get_param_count (info);
+ for (i = 0; i < count; i++)
+ {
+ struct ipcp_lattice *lat = ipcp_get_lattice (info, i);
+
+ fprintf (f, " param [%d]: ", i);
+ if (lat->type == IPA_CONST_VALUE)
+ {
+ fprintf (f, "type is CONST ");
+ print_generic_expr (f, lat->constant, 0);
+ fprintf (f, "\n");
+ }
+ else if (lat->type == IPA_TOP)
+ fprintf (f, "type is TOP\n");
+ else
+ fprintf (f, "type is BOTTOM\n");
+ }
+ }
+}
+
+/* Return true if this NODE is viable candidate for cloning. */
+static bool
+ipcp_cloning_candidate_p (struct cgraph_node *node)
+{
+ int n_calls = 0;
+ int n_hot_calls = 0;
+ gcov_type direct_call_sum = 0;
+ struct cgraph_edge *e;
+
+ /* We never clone functions that are not visible from outside.
+ FIXME: in future we should clone such functions when they are called with
+ different constants, but current ipcp implementation is not good on this.
+ */
+ if (!node->needed || !node->analyzed)
+ return false;
+
+ if (cgraph_function_body_availability (node) <= AVAIL_OVERWRITABLE)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Not considering %s for cloning; body is overwrittable.\n",
+ cgraph_node_name (node));
+ return false;
+ }
+ if (!tree_versionable_function_p (node->decl))
+ {
+ if (dump_file)
+ fprintf (dump_file, "Not considering %s for cloning; body is not versionable.\n",
+ cgraph_node_name (node));
+ return false;
+ }
+ for (e = node->callers; e; e = e->next_caller)
+ {
+ direct_call_sum += e->count;
+ n_calls ++;
+ if (cgraph_maybe_hot_edge_p (e))
+ n_hot_calls ++;
+ }
+
+ if (!n_calls)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Not considering %s for cloning; no direct calls.\n",
+ cgraph_node_name (node));
+ return false;
+ }
+ if (node->local.inline_summary.self_insns < n_calls)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Considering %s for cloning; code would shrink.\n",
+ cgraph_node_name (node));
+ return true;
+ }
+
+ if (!flag_ipa_cp_clone)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Not considering %s for cloning; -fipa-cp-clone disabled.\n",
+ cgraph_node_name (node));
+ return false;
+ }
+
+ if (!optimize_function_for_speed_p (DECL_STRUCT_FUNCTION (node->decl)))
+ {
+ if (dump_file)
+ fprintf (dump_file, "Not considering %s for cloning; optimizing it for size.\n",
+ cgraph_node_name (node));
+ return false;
+ }
+
+ /* When profile is available and function is hot, propagate into it even if
+ calls seems cold; constant propagation can improve function's speed
+ significandly. */
+ if (max_count)
+ {
+ if (direct_call_sum > node->count * 90 / 100)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Considering %s for cloning; usually called directly.\n",
+ cgraph_node_name (node));
+ return true;
+ }
+ }
+ if (!n_hot_calls)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Not considering %s for cloning; no hot calls.\n",
+ cgraph_node_name (node));
+ return false;
+ }
+ if (dump_file)
+ fprintf (dump_file, "Considering %s for cloning.\n",
+ cgraph_node_name (node));
+ return true;
+}
+
+/* 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. */
+static void
+ipcp_initialize_node_lattices (struct cgraph_node *node)
+{
+ int i;
+ struct ipa_node_params *info = IPA_NODE_REF (node);
+ enum ipa_lattice_type type;
+
+ if (ipa_is_called_with_var_arguments (info))
+ type = IPA_BOTTOM;
+ else if (!node->needed)
+ type = IPA_TOP;
+ /* When cloning is allowed, we can assume that externally visible functions
+ are not called. We will compensate this by cloning later. */
+ else if (ipcp_cloning_candidate_p (node))
+ type = IPA_TOP, n_cloning_candidates ++;
+ else
+ type = IPA_BOTTOM;
+
+ for (i = 0; i < ipa_get_param_count (info) ; i++)
+ ipcp_get_lattice (info, i)->type = type;
+}
+
+/* build INTEGER_CST tree with type TREE_TYPE and value according to LAT.
+ Return the tree. */
+static tree
+build_const_val (struct ipcp_lattice *lat, tree tree_type)
+{
+ tree val;
+
+ gcc_assert (ipcp_lat_is_const (lat));
+ val = lat->constant;
+
+ if (!useless_type_conversion_p (tree_type, TREE_TYPE (val)))
+ {
+ if (fold_convertible_p (tree_type, val))
+ return fold_build1 (NOP_EXPR, tree_type, val);
+ else
+ return fold_build1 (VIEW_CONVERT_EXPR, tree_type, val);
+ }
+ return val;
+}
+
+/* Compute the proper scale for NODE. It is the ratio between the number of
+ direct calls (represented on the incoming cgraph_edges) and sum of all
+ invocations of NODE (represented as count in cgraph_node). */
+static void
+ipcp_compute_node_scale (struct cgraph_node *node)
+{
+ gcov_type sum;
+ struct cgraph_edge *cs;
+
+ sum = 0;
+ /* Compute sum of all counts of callers. */
+ for (cs = node->callers; cs != NULL; cs = cs->next_caller)
+ sum += cs->count;
+ if (node->count == 0)
+ ipcp_set_node_scale (node, 0);
+ else
+ 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;
+ struct cgraph_edge *cs;
+
+ for (node = cgraph_nodes; node; node = node->next)
+ if (node->analyzed)
+ ipcp_analyze_node (node);
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ if (!node->analyzed)
+ continue;
+ /* building jump functions */
+ for (cs = node->callees; cs; cs = cs->next_callee)
+ {
+ if (!cs->callee->analyzed)
+ continue;
+ ipa_count_arguments (cs);
+ if (ipa_get_cs_argument_count (IPA_EDGE_REF (cs))
+ != ipa_get_param_count (IPA_NODE_REF (cs->callee)))
+ {
+ /* Handle cases of functions with
+ a variable number of parameters. */
+ ipa_set_called_with_variable_arg (IPA_NODE_REF (cs->callee));
+ if (flag_indirect_inlining)
+ ipa_compute_jump_functions (cs);
+ }
+ else
+ ipa_compute_jump_functions (cs);
+ }
+ }
+}
+
+/* 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. */
+static bool
+ipcp_change_tops_to_bottom (void)
+{
+ int i, count;
+ struct cgraph_node *node;
+ bool prop_again;
+
+ prop_again = false;
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ struct ipa_node_params *info = IPA_NODE_REF (node);
+ count = ipa_get_param_count (info);
+ for (i = 0; i < count; i++)
+ {
+ struct ipcp_lattice *lat = ipcp_get_lattice (info, i);
+ if (lat->type == IPA_TOP)
+ {
+ prop_again = true;
+ if (dump_file)
+ {
+ fprintf (dump_file, "Forcing param ");
+ print_generic_expr (dump_file, ipa_get_param (info, i), 0);
+ fprintf (dump_file, " of node %s to bottom.\n",
+ cgraph_node_name (node));
+ }
+ lat->type = IPA_BOTTOM;
+ }
+ }
+ }
+ return prop_again;
+}
+
+/* Interprocedural analysis. The algorithm propagates constants from the
+ caller's parameters to the callee's arguments. */
+static void
+ipcp_propagate_stage (void)
+{
+ int i;
+ struct ipcp_lattice inc_lat = { IPA_BOTTOM, NULL };
+ struct ipcp_lattice new_lat = { IPA_BOTTOM, NULL };
+ struct ipcp_lattice *dest_lat;
+ struct cgraph_edge *cs;
+ struct ipa_jump_func *jump_func;
+ struct ipa_func_list *wl;
+ int count;
+
+ ipa_check_create_node_params ();
+ ipa_check_create_edge_args ();
+
+ /* Initialize worklist to contain all functions. */
+ wl = ipa_init_func_list ();
+ while (wl)
+ {
+ struct cgraph_node *node = ipa_pop_func_from_list (&wl);
+ struct ipa_node_params *info = IPA_NODE_REF (node);
+
+ for (cs = node->callees; cs; cs = cs->next_callee)
+ {
+ struct ipa_node_params *callee_info = IPA_NODE_REF (cs->callee);
+ struct ipa_edge_args *args = IPA_EDGE_REF (cs);
+
+ if (ipa_is_called_with_var_arguments (callee_info))
+ continue;
+
+ count = ipa_get_cs_argument_count (args);
+ for (i = 0; i < count; i++)
+ {
+ jump_func = ipa_get_ith_jump_func (args, i);
+ ipcp_lattice_from_jfunc (info, &inc_lat, jump_func);
+ dest_lat = ipcp_get_lattice (callee_info, i);
+ ipa_lattice_meet (&new_lat, &inc_lat, dest_lat);
+ if (ipcp_lattice_changed (&new_lat, dest_lat))
+ {
+ dest_lat->type = new_lat.type;
+ dest_lat->constant = new_lat.constant;
+ ipa_push_func_to_list (&wl, cs->callee);
+ }
+ }
+ }
+ }
+}
+
+/* Call the constant propagation algorithm and re-call it if necessary
+ (if there are undetermined values left). */
+static void
+ipcp_iterate_stage (void)
+{
+ struct cgraph_node *node;
+ n_cloning_candidates = 0;
+
+ if (dump_file)
+ fprintf (dump_file, "\nIPA iterate stage:\n\n");
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ ipcp_initialize_node_lattices (node);
+ ipcp_compute_node_scale (node);
+ }
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ ipcp_print_all_lattices (dump_file);
+ ipcp_function_scale_print (dump_file);
+ }
+
+ ipcp_propagate_stage ();
+ if (ipcp_change_tops_to_bottom ())
+ /* Some lattices have changed from IPA_TOP to IPA_BOTTOM.
+ This change should be propagated. */
+ {
+ gcc_assert (n_cloning_candidates);
+ ipcp_propagate_stage ();
+ }
+ if (dump_file)
+ {
+ fprintf (dump_file, "\nIPA lattices after propagation:\n");
+ ipcp_print_all_lattices (dump_file);
+ if (dump_flags & TDF_DETAILS)
+ ipcp_print_profile_data (dump_file);
+ }
+}
+
+/* Check conditions to forbid constant insertion to function described by
+ NODE. */
+static inline bool
+ipcp_node_modifiable_p (struct cgraph_node *node)
+{
+ /* Once we will be able to do in-place replacement, we can be more
+ lax here. */
+ return tree_versionable_function_p (node->decl);
+}
+
+/* Print count scale data structures. */
+static void
+ipcp_function_scale_print (FILE * f)
+{
+ struct cgraph_node *node;
+
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ if (!node->analyzed)
+ continue;
+ fprintf (f, "printing scale for %s: ", cgraph_node_name (node));
+ fprintf (f, "value is " HOST_WIDE_INT_PRINT_DEC
+ " \n", (HOST_WIDE_INT) ipcp_get_node_scale (node));
+ }
+}
+
+/* Print counts of all cgraph nodes. */
+static void
+ipcp_print_func_profile_counts (FILE * f)
+{
+ struct cgraph_node *node;
+
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ fprintf (f, "function %s: ", cgraph_node_name (node));
+ fprintf (f, "count is " HOST_WIDE_INT_PRINT_DEC
+ " \n", (HOST_WIDE_INT) node->count);
+ }
+}
+
+/* Print counts of all cgraph edges. */
+static void
+ipcp_print_call_profile_counts (FILE * f)
+{
+ struct cgraph_node *node;
+ struct cgraph_edge *cs;
+
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ for (cs = node->callees; cs; cs = cs->next_callee)
+ {
+ fprintf (f, "%s -> %s ", cgraph_node_name (cs->caller),
+ cgraph_node_name (cs->callee));
+ fprintf (f, "count is " HOST_WIDE_INT_PRINT_DEC " \n",
+ (HOST_WIDE_INT) cs->count);
+ }
+ }
+}
+
+/* Print all counts and probabilities of cfg edges of all functions. */
+static void
+ipcp_print_edge_profiles (FILE * f)
+{
+ struct cgraph_node *node;
+ basic_block bb;
+ edge_iterator ei;
+ edge e;
+
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ fprintf (f, "function %s: \n", cgraph_node_name (node));
+ if (node->analyzed)
+ {
+ bb =
+ ENTRY_BLOCK_PTR_FOR_FUNCTION (DECL_STRUCT_FUNCTION (node->decl));
+ fprintf (f, "ENTRY: ");
+ fprintf (f, " " HOST_WIDE_INT_PRINT_DEC
+ " %d\n", (HOST_WIDE_INT) bb->count, bb->frequency);
+
+ if (bb->succs)
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ {
+ if (e->dest ==
+ EXIT_BLOCK_PTR_FOR_FUNCTION (DECL_STRUCT_FUNCTION
+ (node->decl)))
+ fprintf (f, "edge ENTRY -> EXIT, Count");
+ else
+ fprintf (f, "edge ENTRY -> %d, Count", e->dest->index);
+ fprintf (f, " " HOST_WIDE_INT_PRINT_DEC
+ " Prob %d\n", (HOST_WIDE_INT) e->count,
+ e->probability);
+ }
+ FOR_EACH_BB_FN (bb, DECL_STRUCT_FUNCTION (node->decl))
+ {
+ fprintf (f, "bb[%d]: ", bb->index);
+ fprintf (f, " " HOST_WIDE_INT_PRINT_DEC
+ " %d\n", (HOST_WIDE_INT) bb->count, bb->frequency);
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ {
+ if (e->dest ==
+ EXIT_BLOCK_PTR_FOR_FUNCTION (DECL_STRUCT_FUNCTION
+ (node->decl)))
+ fprintf (f, "edge %d -> EXIT, Count", e->src->index);
+ else
+ fprintf (f, "edge %d -> %d, Count", e->src->index,
+ e->dest->index);
+ fprintf (f, " " HOST_WIDE_INT_PRINT_DEC " Prob %d\n",
+ (HOST_WIDE_INT) e->count, e->probability);
+ }
+ }
+ }
+ }
+}
+
+/* Print counts and frequencies for all basic blocks of all functions. */
+static void
+ipcp_print_bb_profiles (FILE * f)
+{
+ basic_block bb;
+ struct cgraph_node *node;
+
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ fprintf (f, "function %s: \n", cgraph_node_name (node));
+ if (node->analyzed)
+ {
+ bb =
+ ENTRY_BLOCK_PTR_FOR_FUNCTION (DECL_STRUCT_FUNCTION (node->decl));
+ fprintf (f, "ENTRY: Count");
+ fprintf (f, " " HOST_WIDE_INT_PRINT_DEC
+ " Frequency %d\n", (HOST_WIDE_INT) bb->count,
+ bb->frequency);
+
+ FOR_EACH_BB_FN (bb, DECL_STRUCT_FUNCTION (node->decl))
+ {
+ fprintf (f, "bb[%d]: Count", bb->index);
+ fprintf (f, " " HOST_WIDE_INT_PRINT_DEC
+ " Frequency %d\n", (HOST_WIDE_INT) bb->count,
+ bb->frequency);
+ }
+ bb =
+ EXIT_BLOCK_PTR_FOR_FUNCTION (DECL_STRUCT_FUNCTION (node->decl));
+ fprintf (f, "EXIT: Count");
+ fprintf (f, " " HOST_WIDE_INT_PRINT_DEC
+ " Frequency %d\n", (HOST_WIDE_INT) bb->count,
+ bb->frequency);
+
+ }
+ }
+}
+
+/* Print profile info for all functions. */
+static void
+ipcp_print_profile_data (FILE * f)
+{
+ fprintf (f, "\nNODE COUNTS :\n");
+ ipcp_print_func_profile_counts (f);
+ fprintf (f, "\nCS COUNTS stage:\n");
+ ipcp_print_call_profile_counts (f);
+ fprintf (f, "\nBB COUNTS and FREQUENCIES :\n");
+ ipcp_print_bb_profiles (f);
+ fprintf (f, "\nCFG EDGES COUNTS and PROBABILITIES :\n");
+ ipcp_print_edge_profiles (f);
+}
+
+/* Build and initialize ipa_replace_map struct according to LAT. This struct is
+ processed by versioning, which operates according to the flags set.
+ PARM_TREE is the formal parameter found to be constant. LAT represents the
+ constant. */
+static struct ipa_replace_map *
+ipcp_create_replace_map (tree parm_tree, struct ipcp_lattice *lat)
+{
+ struct ipa_replace_map *replace_map;
+ tree const_val;
+
+ replace_map = XCNEW (struct ipa_replace_map);
+ const_val = build_const_val (lat, TREE_TYPE (parm_tree));
+ if (dump_file)
+ {
+ fprintf (dump_file, " replacing param ");
+ print_generic_expr (dump_file, parm_tree, 0);
+ fprintf (dump_file, " with const ");
+ print_generic_expr (dump_file, const_val, 0);
+ fprintf (dump_file, "\n");
+ }
+ replace_map->old_tree = parm_tree;
+ replace_map->new_tree = const_val;
+ replace_map->replace_p = true;
+ replace_map->ref_p = false;
+
+ return replace_map;
+}
+
+/* Return true if this callsite should be redirected to the original callee
+ (instead of the cloned one). */
+static bool
+ipcp_need_redirect_p (struct cgraph_edge *cs)
+{
+ 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)
+ return false;
+
+ if ((orig = ipcp_get_orig_node (node)) != NULL)
+ node = orig;
+ if (ipcp_get_orig_node (cs->caller))
+ return false;
+
+ orig_callee_info = IPA_NODE_REF (node);
+ count = ipa_get_param_count (orig_callee_info);
+ 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_CONST)
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/* Fix the callsites and the call graph after function cloning was done. */
+static void
+ipcp_update_callgraph (void)
+{
+ struct cgraph_node *node;
+
+ for (node = cgraph_nodes; node; node = node->next)
+ if (node->analyzed && ipcp_node_is_clone (node))
+ {
+ bitmap args_to_skip = BITMAP_ALLOC (NULL);
+ struct cgraph_node *orig_node = ipcp_get_orig_node (node);
+ struct ipa_node_params *info = IPA_NODE_REF (orig_node);
+ int i, count = ipa_get_param_count (info);
+ struct cgraph_edge *cs, *next;
+
+ for (i = 0; i < count; i++)
+ {
+ struct ipcp_lattice *lat = ipcp_get_lattice (info, i);
+ tree parm_tree = ipa_get_param (info, i);
+
+ /* We can proactively remove obviously unused arguments. */
+ if (is_gimple_reg (parm_tree)
+ && !gimple_default_def (DECL_STRUCT_FUNCTION (orig_node->decl),
+ parm_tree))
+ {
+ bitmap_set_bit (args_to_skip, i);
+ continue;
+ }
+
+ if (lat->type == IPA_CONST_VALUE)
+ bitmap_set_bit (args_to_skip, i);
+ }
+ for (cs = node->callers; cs; cs = next)
+ {
+ next = cs->next_caller;
+ if (!cs->indirect_call
+ && (ipcp_node_is_clone (cs->caller)
+ || !ipcp_need_redirect_p (cs)))
+ {
+ gimple new_stmt;
+ gimple_stmt_iterator gsi;
+
+ current_function_decl = cs->caller->decl;
+ push_cfun (DECL_STRUCT_FUNCTION (cs->caller->decl));
+
+ new_stmt = gimple_call_copy_skip_args (cs->call_stmt,
+ args_to_skip);
+ gsi = gsi_for_stmt (cs->call_stmt);
+ gsi_replace (&gsi, new_stmt, true);
+ cgraph_set_call_stmt (cs, new_stmt);
+ pop_cfun ();
+ current_function_decl = NULL;
+ }
+ else
+ {
+ cgraph_redirect_edge_callee (cs, orig_node);
+ gimple_call_set_fndecl (cs->call_stmt, orig_node->decl);
+ }
+ }
+ }
+}
+
+/* Update all cfg basic blocks in NODE according to SCALE. */
+static void
+ipcp_update_bb_counts (struct cgraph_node *node, gcov_type scale)
+{
+ basic_block bb;
+
+ FOR_ALL_BB_FN (bb, DECL_STRUCT_FUNCTION (node->decl))
+ bb->count = bb->count * scale / REG_BR_PROB_BASE;
+}
+
+/* Update all cfg edges in NODE according to SCALE. */
+static void
+ipcp_update_edges_counts (struct cgraph_node *node, gcov_type scale)
+{
+ basic_block bb;
+ edge_iterator ei;
+ edge e;
+
+ FOR_ALL_BB_FN (bb, DECL_STRUCT_FUNCTION (node->decl))
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ e->count = e->count * scale / REG_BR_PROB_BASE;
+}
+
+/* Update profiling info for versioned functions and the functions they were
+ versioned from. */
+static void
+ipcp_update_profiling (void)
+{
+ struct cgraph_node *node, *orig_node;
+ gcov_type scale, scale_complement;
+ struct cgraph_edge *cs;
+
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ if (ipcp_node_is_clone (node))
+ {
+ orig_node = ipcp_get_orig_node (node);
+ scale = ipcp_get_node_scale (orig_node);
+ node->count = orig_node->count * scale / REG_BR_PROB_BASE;
+ scale_complement = REG_BR_PROB_BASE - scale;
+ orig_node->count =
+ orig_node->count * scale_complement / REG_BR_PROB_BASE;
+ for (cs = node->callees; cs; cs = cs->next_callee)
+ cs->count = cs->count * scale / REG_BR_PROB_BASE;
+ for (cs = orig_node->callees; cs; cs = cs->next_callee)
+ cs->count = cs->count * scale_complement / REG_BR_PROB_BASE;
+ ipcp_update_bb_counts (node, scale);
+ ipcp_update_bb_counts (orig_node, scale_complement);
+ ipcp_update_edges_counts (node, scale);
+ ipcp_update_edges_counts (orig_node, scale_complement);
+ }
+ }
+}
+
+/* If NODE was cloned, how much would program grow? */
+static long
+ipcp_estimate_growth (struct cgraph_node *node)
+{
+ struct cgraph_edge *cs;
+ int redirectable_node_callers = 0;
+ int removable_args = 0;
+ bool need_original = node->needed;
+ struct ipa_node_params *info;
+ int i, count;
+ int growth;
+
+ for (cs = node->callers; cs != NULL; cs = cs->next_caller)
+ if (cs->caller == node || !ipcp_need_redirect_p (cs))
+ redirectable_node_callers++;
+ else
+ need_original = true;
+
+ /* If we will be able to fully replace orignal node, we never increase
+ program size. */
+ if (!need_original)
+ return 0;
+
+ info = IPA_NODE_REF (node);
+ count = ipa_get_param_count (info);
+ for (i = 0; i < count; i++)
+ {
+ struct ipcp_lattice *lat = ipcp_get_lattice (info, i);
+ tree parm_tree = ipa_get_param (info, i);
+
+ /* We can proactively remove obviously unused arguments. */
+ if (is_gimple_reg (parm_tree)
+ && !gimple_default_def (DECL_STRUCT_FUNCTION (node->decl),
+ parm_tree))
+ removable_args++;
+
+ if (lat->type == IPA_CONST_VALUE)
+ removable_args++;
+ }
+
+ /* We make just very simple estimate of savings for removal of operand from
+ call site. Precise cost is dificult to get, as our size metric counts
+ constants and moves as free. Generally we are looking for cases that
+ small function is called very many times. */
+ growth = node->local.inline_summary.self_insns
+ - removable_args * redirectable_node_callers;
+ if (growth < 0)
+ return 0;
+ return growth;
+}
+
+
+/* Estimate cost of cloning NODE. */
+static long
+ipcp_estimate_cloning_cost (struct cgraph_node *node)
+{
+ int freq_sum = 1;
+ gcov_type count_sum = 1;
+ struct cgraph_edge *e;
+ int cost;
+
+ cost = ipcp_estimate_growth (node) * 1000;
+ if (!cost)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Versioning of %s will save code size\n",
+ cgraph_node_name (node));
+ return 0;
+ }
+
+ for (e = node->callers; e; e = e->next_caller)
+ if (!bitmap_bit_p (dead_nodes, e->caller->uid)
+ && !ipcp_need_redirect_p (e))
+ {
+ count_sum += e->count;
+ freq_sum += e->frequency + 1;
+ }
+
+ if (max_count)
+ cost /= count_sum * 1000 / max_count + 1;
+ else
+ cost /= freq_sum * 1000 / REG_BR_PROB_BASE + 1;
+ if (dump_file)
+ fprintf (dump_file, "Cost of versioning %s is %i, (size: %i, freq: %i)\n",
+ cgraph_node_name (node), cost, node->local.inline_summary.self_insns,
+ freq_sum);
+ return cost + 1;
+}
+
+/* Return number of live constant parameters. */
+static int
+ipcp_const_param_count (struct cgraph_node *node)
+{
+ int const_param = 0;
+ struct ipa_node_params *info = IPA_NODE_REF (node);
+ int count = ipa_get_param_count (info);
+ int i;
+
+ for (i = 0; i < count; i++)
+ {
+ struct ipcp_lattice *lat = ipcp_get_lattice (info, i);
+ tree parm_tree = ipa_get_param (info, i);
+ if (ipcp_lat_is_insertable (lat)
+ /* Do not count obviously unused arguments. */
+ && (!is_gimple_reg (parm_tree)
+ || gimple_default_def (DECL_STRUCT_FUNCTION (node->decl),
+ parm_tree)))
+ const_param++;
+ }
+ return const_param;
+}
+
+/* Propagate the constant parameters found by ipcp_iterate_stage()
+ to the function's code. */
+static void
+ipcp_insert_stage (void)
+{
+ struct cgraph_node *node, *node1 = NULL;
+ int i;
+ VEC (cgraph_edge_p, heap) * redirect_callers;
+ varray_type replace_trees;
+ int node_callers, count;
+ tree parm_tree;
+ struct ipa_replace_map *replace_param;
+ fibheap_t heap;
+ long overall_insns = 0, new_insns = 0;
+ long max_new_insns;
+
+ ipa_check_create_node_params ();
+ ipa_check_create_edge_args ();
+ if (dump_file)
+ fprintf (dump_file, "\nIPA insert stage:\n\n");
+
+ dead_nodes = BITMAP_ALLOC (NULL);
+
+ for (node = cgraph_nodes; node; node = node->next)
+ if (node->analyzed)
+ {
+ if (node->count > max_count)
+ max_count = node->count;
+ overall_insns += node->local.inline_summary.self_insns;
+ }
+
+ max_new_insns = overall_insns;
+ if (max_new_insns < PARAM_VALUE (PARAM_LARGE_UNIT_INSNS))
+ max_new_insns = PARAM_VALUE (PARAM_LARGE_UNIT_INSNS);
+ max_new_insns = max_new_insns * PARAM_VALUE (PARAM_IPCP_UNIT_GROWTH) / 100 + 1;
+
+ /* First collect all functions we proved to have constant arguments to heap. */
+ heap = fibheap_new ();
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ struct ipa_node_params *info;
+ /* Propagation of the constant is forbidden in certain conditions. */
+ if (!node->analyzed || !ipcp_node_modifiable_p (node))
+ continue;
+ info = IPA_NODE_REF (node);
+ 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);
+ }
+
+ /* Now clone in priority order until code size growth limits are met or
+ heap is emptied. */
+ while (!fibheap_empty (heap))
+ {
+ struct ipa_node_params *info;
+ int growth = 0;
+ bitmap args_to_skip;
+ struct cgraph_edge *cs;
+
+ node = (struct cgraph_node *)fibheap_extract_min (heap);
+ node->aux = NULL;
+ if (dump_file)
+ fprintf (dump_file, "considering function %s\n",
+ cgraph_node_name (node));
+
+ growth = ipcp_estimate_growth (node);
+
+ if (new_insns + growth > max_new_insns)
+ break;
+ if (growth
+ && optimize_function_for_size_p (DECL_STRUCT_FUNCTION (node->decl)))
+ {
+ if (dump_file)
+ fprintf (dump_file, "Not versioning, cold code would grow");
+ continue;
+ }
+
+ new_insns += growth;
+
+ /* Look if original function becomes dead after clonning. */
+ for (cs = node->callers; cs != NULL; cs = cs->next_caller)
+ if (cs->caller == node || ipcp_need_redirect_p (cs))
+ break;
+ if (!cs && !node->needed)
+ bitmap_set_bit (dead_nodes, node->uid);
+
+ info = IPA_NODE_REF (node);
+ count = ipa_get_param_count (info);
+
+ VARRAY_GENERIC_PTR_INIT (replace_trees, ipcp_const_param_count (node),
+ "replace_trees");
+ args_to_skip = BITMAP_ALLOC (NULL);
+ for (i = 0; i < count; i++)
+ {
+ struct ipcp_lattice *lat = ipcp_get_lattice (info, i);
+ parm_tree = ipa_get_param (info, i);
+
+ /* We can proactively remove obviously unused arguments. */
+ if (is_gimple_reg (parm_tree)
+ && !gimple_default_def (DECL_STRUCT_FUNCTION (node->decl),
+ parm_tree))
+ {
+ bitmap_set_bit (args_to_skip, i);
+ continue;
+ }
+
+ if (lat->type == IPA_CONST_VALUE)
+ {
+ replace_param =
+ ipcp_create_replace_map (parm_tree, lat);
+ VARRAY_PUSH_GENERIC_PTR (replace_trees, replace_param);
+ bitmap_set_bit (args_to_skip, i);
+ }
+ }
+
+ /* Compute how many callers node has. */
+ node_callers = 0;
+ for (cs = node->callers; cs != NULL; cs = cs->next_caller)
+ node_callers++;
+ redirect_callers = VEC_alloc (cgraph_edge_p, heap, node_callers);
+ for (cs = node->callers; cs != NULL; cs = cs->next_caller)
+ VEC_quick_push (cgraph_edge_p, redirect_callers, cs);
+
+ /* Redirecting all the callers of the node to the
+ new versioned node. */
+ node1 =
+ cgraph_function_versioning (node, redirect_callers, replace_trees,
+ args_to_skip);
+ BITMAP_FREE (args_to_skip);
+ VEC_free (cgraph_edge_p, heap, redirect_callers);
+ VARRAY_CLEAR (replace_trees);
+ if (node1 == NULL)
+ continue;
+ if (dump_file)
+ fprintf (dump_file, "versioned function %s with growth %i, overall %i\n",
+ cgraph_node_name (node), (int)growth, (int)new_insns);
+ ipcp_init_cloned_node (node, node1);
+
+ /* We've possibly introduced direct calls. */
+ ipcp_update_cloned_node (node1);
+
+ if (dump_file)
+ dump_function_to_file (node1->decl, dump_file, dump_flags);
+
+ for (cs = node->callees; cs; cs = cs->next_callee)
+ if (cs->callee->aux)
+ {
+ fibheap_delete_node (heap, (fibnode_t) cs->callee->aux);
+ cs->callee->aux = fibheap_insert (heap,
+ ipcp_estimate_cloning_cost (cs->callee),
+ cs->callee);
+ }
+ }
+
+ while (!fibheap_empty (heap))
+ {
+ if (dump_file)
+ fprintf (dump_file, "skipping function %s\n",
+ cgraph_node_name (node));
+ node = (struct cgraph_node *) fibheap_extract_min (heap);
+ node->aux = NULL;
+ }
+ fibheap_delete (heap);
+ BITMAP_FREE (dead_nodes);
+ ipcp_update_callgraph ();
+ ipcp_update_profiling ();
+}
+
+/* The IPCP driver. */
+static unsigned int
+ipcp_driver (void)
+{
+ cgraph_remove_unreachable_nodes (true,dump_file);
+ if (dump_file)
+ {
+ fprintf (dump_file, "\nIPA structures before propagation:\n");
+ if (dump_flags & TDF_DETAILS)
+ ipa_print_all_params (dump_file);
+ ipa_print_all_jump_functions (dump_file);
+ }
+ /* 2. Do the interprocedural propagation. */
+ ipcp_iterate_stage ();
+ /* 3. Insert the constants found to the functions. */
+ ipcp_insert_stage ();
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "\nProfiling info after insert stage:\n");
+ ipcp_print_profile_data (dump_file);
+ }
+ /* Free all IPCP structures. */
+ free_all_ipa_structures_after_ipa_cp ();
+ if (dump_file)
+ fprintf (dump_file, "\nIPA constant propagation end\n");
+ return 0;
+}
+
+/* Note function body size. */
+static void
+ipcp_generate_summary (void)
+{
+ 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 ();
+}
+
+/* Gate for IPCP optimization. */
+static bool
+cgraph_gate_cp (void)
+{
+ return flag_ipa_cp;
+}
+
+struct ipa_opt_pass pass_ipa_cp =
+{
+ {
+ IPA_PASS,
+ "cp", /* name */
+ cgraph_gate_cp, /* gate */
+ ipcp_driver, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_IPA_CONSTANT_PROP, /* tv_id */
+ 0, /* properties_required */
+ PROP_trees, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_dump_cgraph | TODO_dump_func |
+ TODO_remove_functions /* todo_flags_finish */
+ },
+ ipcp_generate_summary, /* generate_summary */
+ NULL, /* write_summary */
+ NULL, /* read_summary */
+ NULL, /* function_read_summary */
+ 0, /* TODOs */
+ NULL, /* function_transform */
+ NULL, /* variable_transform */
+};
projects / msp430-gcc.git / blobdiff