--- /dev/null
+/* Interprocedural Identical Code Folding pass
+ Copyright (C) 2014 Free Software Foundation, Inc.
+
+ Contributed by Jan Hubicka <hubicka@ucw.cz> and Martin Liska <mliska@suse.cz>
+
+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/>. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tree.h"
+#include "basic-block.h"
+#include "tree-ssa-alias.h"
+#include "internal-fn.h"
+#include "gimple-expr.h"
+#include "is-a.h"
+#include "gimple.h"
+#include "expr.h"
+#include "gimple-iterator.h"
+#include "gimple-ssa.h"
+#include "tree-cfg.h"
+#include "stringpool.h"
+#include "tree-dfa.h"
+#include "tree-pass.h"
+#include "gimple-pretty-print.h"
+#include "cfgloop.h"
+#include "except.h"
+#include "data-streamer.h"
+#include "ipa-utils.h"
+#include <list>
+#include "tree-ssanames.h"
+#include "tree-eh.h"
+
+#include "ipa-icf-gimple.h"
+#include "ipa-icf.h"
+
+namespace ipa_icf_gimple {
+
+/* Initialize internal structures for a given SOURCE_FUNC_DECL and
+ TARGET_FUNC_DECL. Strict polymorphic comparison is processed if
+ an option COMPARE_POLYMORPHIC is true. For special cases, one can
+ set IGNORE_LABELS to skip label comparison.
+ Similarly, IGNORE_SOURCE_DECLS and IGNORE_TARGET_DECLS are sets
+ of declarations that can be skipped. */
+
+func_checker::func_checker (tree source_func_decl, tree target_func_decl,
+ bool compare_polymorphic,
+ bool ignore_labels,
+ hash_set<symtab_node *> *ignored_source_nodes,
+ hash_set<symtab_node *> *ignored_target_nodes)
+ : m_source_func_decl (source_func_decl), m_target_func_decl (target_func_decl),
+ m_ignored_source_nodes (ignored_source_nodes),
+ m_ignored_target_nodes (ignored_target_nodes),
+ m_compare_polymorphic (compare_polymorphic),
+ m_ignore_labels (ignore_labels)
+{
+ function *source_func = DECL_STRUCT_FUNCTION (source_func_decl);
+ function *target_func = DECL_STRUCT_FUNCTION (target_func_decl);
+
+ unsigned ssa_source = SSANAMES (source_func)->length ();
+ unsigned ssa_target = SSANAMES (target_func)->length ();
+
+ m_source_ssa_names.create (ssa_source);
+ m_target_ssa_names.create (ssa_target);
+
+ for (unsigned i = 0; i < ssa_source; i++)
+ m_source_ssa_names.safe_push (-1);
+
+ for (unsigned i = 0; i < ssa_target; i++)
+ m_target_ssa_names.safe_push (-1);
+}
+
+/* Memory release routine. */
+
+func_checker::~func_checker ()
+{
+ m_source_ssa_names.release();
+ m_target_ssa_names.release();
+}
+
+/* Verifies that trees T1 and T2 are equivalent from perspective of ICF. */
+
+bool
+func_checker::compare_ssa_name (tree t1, tree t2)
+{
+ unsigned i1 = SSA_NAME_VERSION (t1);
+ unsigned i2 = SSA_NAME_VERSION (t2);
+
+ if (m_source_ssa_names[i1] == -1)
+ m_source_ssa_names[i1] = i2;
+ else if (m_source_ssa_names[i1] != (int) i2)
+ return false;
+
+ if(m_target_ssa_names[i2] == -1)
+ m_target_ssa_names[i2] = i1;
+ else if (m_target_ssa_names[i2] != (int) i1)
+ return false;
+
+ return true;
+}
+
+/* Verification function for edges E1 and E2. */
+
+bool
+func_checker::compare_edge (edge e1, edge e2)
+{
+ if (e1->flags != e2->flags)
+ return false;
+
+ bool existed_p;
+
+ edge &slot = m_edge_map.get_or_insert (e1, &existed_p);
+ if (existed_p)
+ return return_with_debug (slot == e2);
+ else
+ slot = e2;
+
+ /* TODO: filter edge probabilities for profile feedback match. */
+
+ return true;
+}
+
+/* Verification function for declaration trees T1 and T2 that
+ come from functions FUNC1 and FUNC2. */
+
+bool
+func_checker::compare_decl (tree t1, tree t2)
+{
+ if (!auto_var_in_fn_p (t1, m_source_func_decl)
+ || !auto_var_in_fn_p (t2, m_target_func_decl))
+ return return_with_debug (t1 == t2);
+
+ tree_code t = TREE_CODE (t1);
+ if ((t == VAR_DECL || t == PARM_DECL || t == RESULT_DECL)
+ && DECL_BY_REFERENCE (t1) != DECL_BY_REFERENCE (t2))
+ return return_false_with_msg ("DECL_BY_REFERENCE flags are different");
+
+ if (!compatible_types_p (TREE_TYPE (t1), TREE_TYPE (t2),
+ m_compare_polymorphic))
+ return return_false ();
+
+ bool existed_p;
+
+ tree &slot = m_decl_map.get_or_insert (t1, &existed_p);
+ if (existed_p)
+ return return_with_debug (slot == t2);
+ else
+ slot = t2;
+
+ return true;
+}
+
+/* Return true if types are compatible from perspective of ICF. */
+bool func_checker::compatible_types_p (tree t1, tree t2,
+ bool compare_polymorphic,
+ bool first_argument)
+{
+ if (TREE_CODE (t1) != TREE_CODE (t2))
+ return return_false_with_msg ("different tree types");
+
+ if (!types_compatible_p (t1, t2))
+ return return_false_with_msg ("types are not compatible");
+
+ if (get_alias_set (t1) != get_alias_set (t2))
+ return return_false_with_msg ("alias sets are different");
+
+ /* We call contains_polymorphic_type_p with this pointer type. */
+ if (first_argument && TREE_CODE (t1) == POINTER_TYPE)
+ {
+ t1 = TREE_TYPE (t1);
+ t2 = TREE_TYPE (t2);
+ }
+
+ if (compare_polymorphic)
+ if (contains_polymorphic_type_p (t1) || contains_polymorphic_type_p (t2))
+ {
+ if (!contains_polymorphic_type_p (t1) || !contains_polymorphic_type_p (t2))
+ return return_false_with_msg ("one type is not polymorphic");
+
+ if (!types_must_be_same_for_odr (t1, t2))
+ return return_false_with_msg ("types are not same for ODR");
+ }
+
+ return true;
+}
+
+/* Function responsible for comparison of handled components T1 and T2.
+ If these components, from functions FUNC1 and FUNC2, are equal, true
+ is returned. */
+
+bool
+func_checker::compare_operand (tree t1, tree t2)
+{
+ tree base1, base2, x1, x2, y1, y2, z1, z2;
+ HOST_WIDE_INT offset1 = 0, offset2 = 0;
+ bool ret;
+
+ if (!t1 && !t2)
+ return true;
+ else if (!t1 || !t2)
+ return false;
+
+ tree tt1 = TREE_TYPE (t1);
+ tree tt2 = TREE_TYPE (t2);
+
+ if (!func_checker::compatible_types_p (tt1, tt2))
+ return false;
+
+ base1 = get_addr_base_and_unit_offset (t1, &offset1);
+ base2 = get_addr_base_and_unit_offset (t2, &offset2);
+
+ if (base1 && base2)
+ {
+ if (offset1 != offset2)
+ return return_false_with_msg ("base offsets are different");
+
+ t1 = base1;
+ t2 = base2;
+ }
+
+ if (TREE_CODE (t1) != TREE_CODE (t2))
+ return return_false ();
+
+ switch (TREE_CODE (t1))
+ {
+ case CONSTRUCTOR:
+ {
+ unsigned length1 = vec_safe_length (CONSTRUCTOR_ELTS (t1));
+ unsigned length2 = vec_safe_length (CONSTRUCTOR_ELTS (t2));
+
+ if (length1 != length2)
+ return return_false ();
+
+ for (unsigned i = 0; i < length1; i++)
+ if (!compare_operand (CONSTRUCTOR_ELT (t1, i)->value,
+ CONSTRUCTOR_ELT (t2, i)->value))
+ return return_false();
+
+ return true;
+ }
+ case ARRAY_REF:
+ case ARRAY_RANGE_REF:
+ x1 = TREE_OPERAND (t1, 0);
+ x2 = TREE_OPERAND (t2, 0);
+ y1 = TREE_OPERAND (t1, 1);
+ y2 = TREE_OPERAND (t2, 1);
+
+ if (!compare_operand (array_ref_low_bound (t1),
+ array_ref_low_bound (t2)))
+ return return_false_with_msg ("");
+ if (!compare_operand (array_ref_element_size (t1),
+ array_ref_element_size (t2)))
+ return return_false_with_msg ("");
+ if (!compare_operand (x1, x2))
+ return return_false_with_msg ("");
+ return compare_operand (y1, y2);
+ case MEM_REF:
+ {
+ x1 = TREE_OPERAND (t1, 0);
+ x2 = TREE_OPERAND (t2, 0);
+ y1 = TREE_OPERAND (t1, 1);
+ y2 = TREE_OPERAND (t2, 1);
+
+ /* See if operand is an memory access (the test originate from
+ gimple_load_p).
+
+ In this case the alias set of the function being replaced must
+ be subset of the alias set of the other function. At the moment
+ we seek for equivalency classes, so simply require inclussion in
+ both directions. */
+
+ if (!func_checker::compatible_types_p (TREE_TYPE (x1), TREE_TYPE (x2)))
+ return return_false ();
+
+ if (!compare_operand (x1, x2))
+ return return_false_with_msg ("");
+
+ if (get_alias_set (TREE_TYPE (y1)) != get_alias_set (TREE_TYPE (y2)))
+ return return_false_with_msg ("alias set for MEM_REF offsets are different");
+
+ ao_ref r1, r2;
+ ao_ref_init (&r1, t1);
+ ao_ref_init (&r2, t2);
+ if (ao_ref_alias_set (&r1) != ao_ref_alias_set (&r2)
+ || ao_ref_base_alias_set (&r1) != ao_ref_base_alias_set (&r2))
+ return return_false_with_msg ("ao alias sets are different");
+
+ /* Type of the offset on MEM_REF does not matter. */
+ return wi::to_offset (y1) == wi::to_offset (y2);
+ }
+ case COMPONENT_REF:
+ {
+ x1 = TREE_OPERAND (t1, 0);
+ x2 = TREE_OPERAND (t2, 0);
+ y1 = TREE_OPERAND (t1, 1);
+ y2 = TREE_OPERAND (t2, 1);
+
+ ret = compare_operand (x1, x2)
+ && compare_operand (y1, y2);
+
+ return return_with_debug (ret);
+ }
+ /* Virtual table call. */
+ case OBJ_TYPE_REF:
+ {
+ x1 = TREE_OPERAND (t1, 0);
+ x2 = TREE_OPERAND (t2, 0);
+ y1 = TREE_OPERAND (t1, 1);
+ y2 = TREE_OPERAND (t2, 1);
+ z1 = TREE_OPERAND (t1, 2);
+ z2 = TREE_OPERAND (t2, 2);
+
+ ret = compare_operand (x1, x2)
+ && compare_operand (y1, y2)
+ && compare_operand (z1, z2);
+
+ return return_with_debug (ret);
+ }
+ case ADDR_EXPR:
+ {
+ x1 = TREE_OPERAND (t1, 0);
+ x2 = TREE_OPERAND (t2, 0);
+
+ ret = compare_operand (x1, x2);
+ return return_with_debug (ret);
+ }
+ case SSA_NAME:
+ {
+ ret = compare_ssa_name (t1, t2);
+
+ if (!ret)
+ return return_with_debug (ret);
+
+ if (SSA_NAME_IS_DEFAULT_DEF (t1))
+ {
+ tree b1 = SSA_NAME_VAR (t1);
+ tree b2 = SSA_NAME_VAR (t2);
+
+ if (b1 == NULL && b2 == NULL)
+ return true;
+
+ if (b1 == NULL || b2 == NULL || TREE_CODE (b1) != TREE_CODE (b2))
+ return return_false ();
+
+ switch (TREE_CODE (b1))
+ {
+ case VAR_DECL:
+ return return_with_debug (compare_variable_decl (t1, t2));
+ case PARM_DECL:
+ case RESULT_DECL:
+ ret = compare_decl (b1, b2);
+ return return_with_debug (ret);
+ default:
+ return return_false_with_msg ("Unknown TREE code reached");
+ }
+ }
+ else
+ return true;
+ }
+ case INTEGER_CST:
+ {
+ ret = compatible_types_p (TREE_TYPE (t1), TREE_TYPE (t2))
+ && wi::to_offset (t1) == wi::to_offset (t2);
+
+ return return_with_debug (ret);
+ }
+ case COMPLEX_CST:
+ case VECTOR_CST:
+ case STRING_CST:
+ case REAL_CST:
+ {
+ ret = operand_equal_p (t1, t2, OEP_ONLY_CONST);
+ return return_with_debug (ret);
+ }
+ case FUNCTION_DECL:
+ {
+ ret = compare_function_decl (t1, t2);
+ return return_with_debug (ret);
+ }
+ case VAR_DECL:
+ return return_with_debug (compare_variable_decl (t1, t2));
+ case FIELD_DECL:
+ {
+ tree offset1 = DECL_FIELD_OFFSET (t1);
+ tree offset2 = DECL_FIELD_OFFSET (t2);
+
+ tree bit_offset1 = DECL_FIELD_BIT_OFFSET (t1);
+ tree bit_offset2 = DECL_FIELD_BIT_OFFSET (t2);
+
+ ret = compare_operand (offset1, offset2)
+ && compare_operand (bit_offset1, bit_offset2);
+
+ return return_with_debug (ret);
+ }
+ case LABEL_DECL:
+ {
+ int *bb1 = m_label_bb_map.get (t1);
+ int *bb2 = m_label_bb_map.get (t2);
+
+ return return_with_debug (*bb1 == *bb2);
+ }
+ case PARM_DECL:
+ case RESULT_DECL:
+ case CONST_DECL:
+ case BIT_FIELD_REF:
+ {
+ ret = compare_decl (t1, t2);
+ return return_with_debug (ret);
+ }
+ default:
+ return return_false_with_msg ("Unknown TREE code reached");
+ }
+}
+
+/* Compares two tree list operands T1 and T2 and returns true if these
+ two trees are semantically equivalent. */
+
+bool
+func_checker::compare_tree_list_operand (tree t1, tree t2)
+{
+ gcc_assert (TREE_CODE (t1) == TREE_LIST);
+ gcc_assert (TREE_CODE (t2) == TREE_LIST);
+
+ for (; t1; t1 = TREE_CHAIN (t1))
+ {
+ if (!t2)
+ return false;
+
+ if (!compare_operand (TREE_VALUE (t1), TREE_VALUE (t2)))
+ return return_false ();
+
+ t2 = TREE_CHAIN (t2);
+ }
+
+ if (t2)
+ return return_false ();
+
+ return true;
+}
+
+/* Verifies that trees T1 and T2, representing function declarations
+ are equivalent from perspective of ICF. */
+
+bool
+func_checker::compare_function_decl (tree t1, tree t2)
+{
+ bool ret = false;
+
+ if (t1 == t2)
+ return true;
+
+ symtab_node *n1 = symtab_node::get (t1);
+ symtab_node *n2 = symtab_node::get (t2);
+
+ if (m_ignored_source_nodes != NULL && m_ignored_target_nodes != NULL)
+ {
+ ret = m_ignored_source_nodes->contains (n1)
+ && m_ignored_target_nodes->contains (n2);
+
+ if (ret)
+ return true;
+ }
+
+ /* If function decl is WEAKREF, we compare targets. */
+ cgraph_node *f1 = cgraph_node::get (t1);
+ cgraph_node *f2 = cgraph_node::get (t2);
+
+ if(f1 && f2 && f1->weakref && f2->weakref)
+ ret = f1->alias_target == f2->alias_target;
+
+ return ret;
+}
+
+/* Verifies that trees T1 and T2 do correspond. */
+
+bool
+func_checker::compare_variable_decl (tree t1, tree t2)
+{
+ bool ret = false;
+
+ if (t1 == t2)
+ return true;
+
+ if (TREE_CODE (t1) == VAR_DECL && (DECL_EXTERNAL (t1) || TREE_STATIC (t1)))
+ {
+ symtab_node *n1 = symtab_node::get (t1);
+ symtab_node *n2 = symtab_node::get (t2);
+
+ if (m_ignored_source_nodes != NULL && m_ignored_target_nodes != NULL)
+ {
+ ret = m_ignored_source_nodes->contains (n1)
+ && m_ignored_target_nodes->contains (n2);
+
+ if (ret)
+ return true;
+ }
+ }
+ ret = compare_decl (t1, t2);
+
+ return return_with_debug (ret);
+}
+
+void
+func_checker::parse_labels (sem_bb *bb)
+{
+ for (gimple_stmt_iterator gsi = gsi_start_bb (bb->bb); !gsi_end_p (gsi);
+ gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+
+ if (gimple_code (stmt) == GIMPLE_LABEL)
+ {
+ tree t = gimple_label_label (stmt);
+ gcc_assert (TREE_CODE (t) == LABEL_DECL);
+
+ m_label_bb_map.put (t, bb->bb->index);
+ }
+ }
+}
+
+/* Basic block equivalence comparison function that returns true if
+ basic blocks BB1 and BB2 (from functions FUNC1 and FUNC2) correspond.
+
+ In general, a collection of equivalence dictionaries is built for types
+ like SSA names, declarations (VAR_DECL, PARM_DECL, ..). This infrastructure
+ is utilized by every statement-by-stament comparison function. */
+
+bool
+func_checker::compare_bb (sem_bb *bb1, sem_bb *bb2)
+{
+ unsigned i;
+ gimple_stmt_iterator gsi1, gsi2;
+ gimple s1, s2;
+
+ if (bb1->nondbg_stmt_count != bb2->nondbg_stmt_count
+ || bb1->edge_count != bb2->edge_count)
+ return return_false ();
+
+ gsi1 = gsi_start_bb (bb1->bb);
+ gsi2 = gsi_start_bb (bb2->bb);
+
+ for (i = 0; i < bb1->nondbg_stmt_count; i++)
+ {
+ if (is_gimple_debug (gsi_stmt (gsi1)))
+ gsi_next_nondebug (&gsi1);
+
+ if (is_gimple_debug (gsi_stmt (gsi2)))
+ gsi_next_nondebug (&gsi2);
+
+ s1 = gsi_stmt (gsi1);
+ s2 = gsi_stmt (gsi2);
+
+ int eh1 = lookup_stmt_eh_lp_fn
+ (DECL_STRUCT_FUNCTION (m_source_func_decl), s1);
+ int eh2 = lookup_stmt_eh_lp_fn
+ (DECL_STRUCT_FUNCTION (m_target_func_decl), s2);
+
+ if (eh1 != eh2)
+ return return_false_with_msg ("EH regions are different");
+
+ if (gimple_code (s1) != gimple_code (s2))
+ return return_false_with_msg ("gimple codes are different");
+
+ switch (gimple_code (s1))
+ {
+ case GIMPLE_CALL:
+ if (!compare_gimple_call (s1, s2))
+ return return_different_stmts (s1, s2, "GIMPLE_CALL");
+ break;
+ case GIMPLE_ASSIGN:
+ if (!compare_gimple_assign (s1, s2))
+ return return_different_stmts (s1, s2, "GIMPLE_ASSIGN");
+ break;
+ case GIMPLE_COND:
+ if (!compare_gimple_cond (s1, s2))
+ return return_different_stmts (s1, s2, "GIMPLE_COND");
+ break;
+ case GIMPLE_SWITCH:
+ if (!compare_gimple_switch (s1, s2))
+ return return_different_stmts (s1, s2, "GIMPLE_SWITCH");
+ break;
+ case GIMPLE_DEBUG:
+ case GIMPLE_EH_DISPATCH:
+ break;
+ case GIMPLE_RESX:
+ if (!compare_gimple_resx (s1, s2))
+ return return_different_stmts (s1, s2, "GIMPLE_RESX");
+ break;
+ case GIMPLE_LABEL:
+ if (!compare_gimple_label (s1, s2))
+ return return_different_stmts (s1, s2, "GIMPLE_LABEL");
+ break;
+ case GIMPLE_RETURN:
+ if (!compare_gimple_return (s1, s2))
+ return return_different_stmts (s1, s2, "GIMPLE_RETURN");
+ break;
+ case GIMPLE_GOTO:
+ if (!compare_gimple_goto (s1, s2))
+ return return_different_stmts (s1, s2, "GIMPLE_GOTO");
+ break;
+ case GIMPLE_ASM:
+ if (!compare_gimple_asm (s1, s2))
+ return return_different_stmts (s1, s2, "GIMPLE_ASM");
+ break;
+ case GIMPLE_PREDICT:
+ case GIMPLE_NOP:
+ return true;
+ default:
+ return return_false_with_msg ("Unknown GIMPLE code reached");
+ }
+
+ gsi_next (&gsi1);
+ gsi_next (&gsi2);
+ }
+
+ return true;
+}
+
+/* Verifies for given GIMPLEs S1 and S2 that
+ call statements are semantically equivalent. */
+
+bool
+func_checker::compare_gimple_call (gimple s1, gimple s2)
+{
+ unsigned i;
+ tree t1, t2;
+
+ if (gimple_call_num_args (s1) != gimple_call_num_args (s2))
+ return false;
+
+ t1 = gimple_call_fndecl (s1);
+ t2 = gimple_call_fndecl (s2);
+
+ /* Function pointer variables are not supported yet. */
+ if (!compare_operand (t1, t2))
+ return return_false();
+
+ /* Checking of argument. */
+ for (i = 0; i < gimple_call_num_args (s1); ++i)
+ {
+ t1 = gimple_call_arg (s1, i);
+ t2 = gimple_call_arg (s2, i);
+
+ if (!compare_operand (t1, t2))
+ return false;
+ }
+
+ /* Return value checking. */
+ t1 = gimple_get_lhs (s1);
+ t2 = gimple_get_lhs (s2);
+
+ return compare_operand (t1, t2);
+}
+
+
+/* Verifies for given GIMPLEs S1 and S2 that
+ assignment statements are semantically equivalent. */
+
+bool
+func_checker::compare_gimple_assign (gimple s1, gimple s2)
+{
+ tree arg1, arg2;
+ tree_code code1, code2;
+ unsigned i;
+
+ code1 = gimple_expr_code (s1);
+ code2 = gimple_expr_code (s2);
+
+ if (code1 != code2)
+ return false;
+
+ code1 = gimple_assign_rhs_code (s1);
+ code2 = gimple_assign_rhs_code (s2);
+
+ if (code1 != code2)
+ return false;
+
+ for (i = 0; i < gimple_num_ops (s1); i++)
+ {
+ arg1 = gimple_op (s1, i);
+ arg2 = gimple_op (s2, i);
+
+ if (!compare_operand (arg1, arg2))
+ return false;
+ }
+
+
+ return true;
+}
+
+/* Verifies for given GIMPLEs S1 and S2 that
+ condition statements are semantically equivalent. */
+
+bool
+func_checker::compare_gimple_cond (gimple s1, gimple s2)
+{
+ tree t1, t2;
+ tree_code code1, code2;
+
+ code1 = gimple_expr_code (s1);
+ code2 = gimple_expr_code (s2);
+
+ if (code1 != code2)
+ return false;
+
+ t1 = gimple_cond_lhs (s1);
+ t2 = gimple_cond_lhs (s2);
+
+ if (!compare_operand (t1, t2))
+ return false;
+
+ t1 = gimple_cond_rhs (s1);
+ t2 = gimple_cond_rhs (s2);
+
+ return compare_operand (t1, t2);
+}
+
+/* Verifies that tree labels T1 and T2 correspond in FUNC1 and FUNC2. */
+
+bool
+func_checker::compare_tree_ssa_label (tree t1, tree t2)
+{
+ return compare_operand (t1, t2);
+}
+
+/* Verifies for given GIMPLEs S1 and S2 that
+ label statements are semantically equivalent. */
+
+bool
+func_checker::compare_gimple_label (gimple g1, gimple g2)
+{
+ if (m_ignore_labels)
+ return true;
+
+ tree t1 = gimple_label_label (g1);
+ tree t2 = gimple_label_label (g2);
+
+ if (FORCED_LABEL (t1) || FORCED_LABEL (t2))
+ return return_false_with_msg ("FORCED_LABEL");
+
+ return compare_tree_ssa_label (t1, t2);
+}
+
+/* Verifies for given GIMPLEs S1 and S2 that
+ switch statements are semantically equivalent. */
+
+bool
+func_checker::compare_gimple_switch (gimple g1, gimple g2)
+{
+ unsigned lsize1, lsize2, i;
+
+ lsize1 = gimple_switch_num_labels (g1);
+ lsize2 = gimple_switch_num_labels (g2);
+
+ if (lsize1 != lsize2)
+ return false;
+
+ tree t1 = gimple_switch_index (g1);
+ tree t2 = gimple_switch_index (g2);
+
+ if (!compare_operand (t1, t2))
+ return false;
+
+ for (i = 0; i < lsize1; i++)
+ {
+ tree label1 = gimple_switch_label (g1, i);
+ tree label2 = gimple_switch_label (g2, i);
+
+ if (TREE_CODE (label1) == CASE_LABEL_EXPR
+ && TREE_CODE (label2) == CASE_LABEL_EXPR)
+ {
+ label1 = CASE_LABEL (label1);
+ label2 = CASE_LABEL (label2);
+
+ if (!compare_operand (label1, label2))
+ return return_false_with_msg ("switch label_exprs are different");
+ }
+ else if (!tree_int_cst_equal (label1, label2))
+ return return_false_with_msg ("switch labels are different");
+ }
+
+ return true;
+}
+
+/* Verifies for given GIMPLEs S1 and S2 that
+ return statements are semantically equivalent. */
+
+bool
+func_checker::compare_gimple_return (gimple g1, gimple g2)
+{
+ tree t1, t2;
+
+ t1 = gimple_return_retval (g1);
+ t2 = gimple_return_retval (g2);
+
+ /* Void return type. */
+ if (t1 == NULL && t2 == NULL)
+ return true;
+ else
+ return compare_operand (t1, t2);
+}
+
+/* Verifies for given GIMPLEs S1 and S2 that
+ goto statements are semantically equivalent. */
+
+bool
+func_checker::compare_gimple_goto (gimple g1, gimple g2)
+{
+ tree dest1, dest2;
+
+ dest1 = gimple_goto_dest (g1);
+ dest2 = gimple_goto_dest (g2);
+
+ if (TREE_CODE (dest1) != TREE_CODE (dest2) || TREE_CODE (dest1) != SSA_NAME)
+ return false;
+
+ return compare_operand (dest1, dest2);
+}
+
+/* Verifies for given GIMPLEs S1 and S2 that
+ resx statements are semantically equivalent. */
+
+bool
+func_checker::compare_gimple_resx (gimple g1, gimple g2)
+{
+ return gimple_resx_region (g1) == gimple_resx_region (g2);
+}
+
+/* Verifies for given GIMPLEs S1 and S2 that ASM statements are equivalent.
+ For the beginning, the pass only supports equality for
+ '__asm__ __volatile__ ("", "", "", "memory")'. */
+
+bool
+func_checker::compare_gimple_asm (gimple g1, gimple g2)
+{
+ if (gimple_asm_volatile_p (g1) != gimple_asm_volatile_p (g2))
+ return false;
+
+ if (gimple_asm_ninputs (g1) != gimple_asm_ninputs (g2))
+ return false;
+
+ if (gimple_asm_noutputs (g1) != gimple_asm_noutputs (g2))
+ return false;
+
+ /* We do not suppport goto ASM statement comparison. */
+ if (gimple_asm_nlabels (g1) || gimple_asm_nlabels (g2))
+ return false;
+
+ if (gimple_asm_nclobbers (g1) != gimple_asm_nclobbers (g2))
+ return false;
+
+ for (unsigned i = 0; i < gimple_asm_ninputs (g1); i++)
+ {
+ tree input1 = gimple_asm_input_op (g1, i);
+ tree input2 = gimple_asm_input_op (g2, i);
+
+ if (!compare_tree_list_operand (input1, input2))
+ return return_false_with_msg ("ASM input is different");
+ }
+
+ for (unsigned i = 0; i < gimple_asm_noutputs (g1); i++)
+ {
+ tree output1 = gimple_asm_output_op (g1, i);
+ tree output2 = gimple_asm_output_op (g2, i);
+
+ if (!compare_tree_list_operand (output1, output2))
+ return return_false_with_msg ("ASM output is different");
+ }
+
+ for (unsigned i = 0; i < gimple_asm_nclobbers (g1); i++)
+ {
+ tree clobber1 = gimple_asm_clobber_op (g1, i);
+ tree clobber2 = gimple_asm_clobber_op (g2, i);
+
+ if (!operand_equal_p (TREE_VALUE (clobber1), TREE_VALUE (clobber2),
+ OEP_ONLY_CONST))
+ return return_false_with_msg ("ASM clobber is different");
+ }
+
+ return true;
+}
+
+} // ipa_icf_gimple namespace
--- /dev/null
+/* Interprocedural Identical Code Folding pass
+ Copyright (C) 2014 Free Software Foundation, Inc.
+
+ Contributed by Jan Hubicka <hubicka@ucw.cz> and Martin Liska <mliska@suse.cz>
+
+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 Identical Code Folding for functions and
+ read-only variables.
+
+ The goal of this transformation is to discover functions and read-only
+ variables which do have exactly the same semantics.
+
+ In case of functions,
+ we could either create a virtual clone or do a simple function wrapper
+ that will call equivalent function. If the function is just locally visible,
+ all function calls can be redirected. For read-only variables, we create
+ aliases if possible.
+
+ Optimization pass arranges as follows:
+ 1) All functions and read-only variables are visited and internal
+ data structure, either sem_function or sem_variables is created.
+ 2) For every symbol from the previous step, VAR_DECL and FUNCTION_DECL are
+ saved and matched to corresponding sem_items.
+ 3) These declaration are ignored for equality check and are solved
+ by Value Numbering algorithm published by Alpert, Zadeck in 1992.
+ 4) We compute hash value for each symbol.
+ 5) Congruence classes are created based on hash value. If hash value are
+ equal, equals function is called and symbols are deeply compared.
+ We must prove that all SSA names, declarations and other items
+ correspond.
+ 6) Value Numbering is executed for these classes. At the end of the process
+ all symbol members in remaining classes can be merged.
+ 7) Merge operation creates alias in case of read-only variables. For
+ callgraph node, we must decide if we can redirect local calls,
+ create an alias or a thunk.
+
+*/
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tree.h"
+#include "basic-block.h"
+#include "tree-ssa-alias.h"
+#include "internal-fn.h"
+#include "gimple-expr.h"
+#include "is-a.h"
+#include "gimple.h"
+#include "expr.h"
+#include "gimple-iterator.h"
+#include "gimple-ssa.h"
+#include "tree-cfg.h"
+#include "tree-phinodes.h"
+#include "stringpool.h"
+#include "tree-ssanames.h"
+#include "tree-dfa.h"
+#include "tree-pass.h"
+#include "gimple-pretty-print.h"
+#include "ipa-inline.h"
+#include "cfgloop.h"
+#include "except.h"
+#include "hash-table.h"
+#include "coverage.h"
+#include "attribs.h"
+#include "print-tree.h"
+#include "lto-streamer.h"
+#include "data-streamer.h"
+#include "ipa-utils.h"
+#include <list>
+#include "ipa-icf-gimple.h"
+#include "ipa-icf.h"
+
+using namespace ipa_icf_gimple;
+
+namespace ipa_icf {
+/* Constructor for key value pair, where _ITEM is key and _INDEX is a target. */
+
+sem_usage_pair::sem_usage_pair (sem_item *_item, unsigned int _index):
+ item (_item), index (_index)
+{
+}
+
+/* Semantic item constructor for a node of _TYPE, where STACK is used
+ for bitmap memory allocation. */
+
+sem_item::sem_item (sem_item_type _type,
+ bitmap_obstack *stack): type(_type), hash(0)
+{
+ setup (stack);
+}
+
+/* Semantic item constructor for a node of _TYPE, where STACK is used
+ for bitmap memory allocation. The item is based on symtab node _NODE
+ with computed _HASH. */
+
+sem_item::sem_item (sem_item_type _type, symtab_node *_node,
+ hashval_t _hash, bitmap_obstack *stack): type(_type),
+ node (_node), hash (_hash)
+{
+ decl = node->decl;
+ setup (stack);
+}
+
+/* Add reference to a semantic TARGET. */
+
+void
+sem_item::add_reference (sem_item *target)
+{
+ refs.safe_push (target);
+ unsigned index = refs.length ();
+ target->usages.safe_push (new sem_usage_pair(this, index));
+ bitmap_set_bit (target->usage_index_bitmap, index);
+ refs_set.add (target->node);
+}
+
+/* Initialize internal data structures. Bitmap STACK is used for
+ bitmap memory allocation process. */
+
+void
+sem_item::setup (bitmap_obstack *stack)
+{
+ gcc_checking_assert (node);
+
+ refs.create (0);
+ tree_refs.create (0);
+ usages.create (0);
+ usage_index_bitmap = BITMAP_ALLOC (stack);
+}
+
+sem_item::~sem_item ()
+{
+ for (unsigned i = 0; i < usages.length (); i++)
+ delete usages[i];
+
+ refs.release ();
+ tree_refs.release ();
+ usages.release ();
+
+ BITMAP_FREE (usage_index_bitmap);
+}
+
+/* Dump function for debugging purpose. */
+
+DEBUG_FUNCTION void
+sem_item::dump (void)
+{
+ if (dump_file)
+ {
+ fprintf (dump_file, "[%s] %s (%u) (tree:%p)\n", type == FUNC ? "func" : "var",
+ name(), node->order, (void *) node->decl);
+ fprintf (dump_file, " hash: %u\n", get_hash ());
+ fprintf (dump_file, " references: ");
+
+ for (unsigned i = 0; i < refs.length (); i++)
+ fprintf (dump_file, "%s%s ", refs[i]->name (),
+ i < refs.length() - 1 ? "," : "");
+
+ fprintf (dump_file, "\n");
+ }
+}
+
+/* Semantic function constructor that uses STACK as bitmap memory stack. */
+
+sem_function::sem_function (bitmap_obstack *stack): sem_item (FUNC, stack),
+ m_checker (NULL), m_compared_func (NULL)
+{
+ arg_types.create (0);
+ bb_sizes.create (0);
+ bb_sorted.create (0);
+}
+
+/* Constructor based on callgraph node _NODE with computed hash _HASH.
+ Bitmap STACK is used for memory allocation. */
+sem_function::sem_function (cgraph_node *node, hashval_t hash,
+ bitmap_obstack *stack):
+ sem_item (FUNC, node, hash, stack),
+ m_checker (NULL), m_compared_func (NULL)
+{
+ arg_types.create (0);
+ bb_sizes.create (0);
+ bb_sorted.create (0);
+}
+
+sem_function::~sem_function ()
+{
+ for (unsigned i = 0; i < bb_sorted.length (); i++)
+ free (bb_sorted[i]);
+
+ arg_types.release ();
+ bb_sizes.release ();
+ bb_sorted.release ();
+}
+
+/* Calculates hash value based on a BASIC_BLOCK. */
+
+hashval_t
+sem_function::get_bb_hash (const sem_bb *basic_block)
+{
+ inchash::hash hstate;
+
+ hstate.add_int (basic_block->nondbg_stmt_count);
+ hstate.add_int (basic_block->edge_count);
+
+ return hstate.end ();
+}
+
+/* References independent hash function. */
+
+hashval_t
+sem_function::get_hash (void)
+{
+ if(!hash)
+ {
+ inchash::hash hstate;
+ hstate.add_int (177454); /* Random number for function type. */
+
+ hstate.add_int (arg_count);
+ hstate.add_int (cfg_checksum);
+ hstate.add_int (gcode_hash);
+
+ for (unsigned i = 0; i < bb_sorted.length (); i++)
+ hstate.merge_hash (get_bb_hash (bb_sorted[i]));
+
+ for (unsigned i = 0; i < bb_sizes.length (); i++)
+ hstate.add_int (bb_sizes[i]);
+
+ hash = hstate.end ();
+ }
+
+ return hash;
+}
+
+/* For a given symbol table nodes N1 and N2, we check that FUNCTION_DECLs
+ point to a same function. Comparison can be skipped if IGNORED_NODES
+ contains these nodes. */
+
+bool
+sem_function::compare_cgraph_references (hash_map <symtab_node *, sem_item *>
+ &ignored_nodes,
+ symtab_node *n1, symtab_node *n2)
+{
+ if (n1 == n2 || (ignored_nodes.get (n1) && ignored_nodes.get (n2)))
+ return true;
+
+ /* TODO: add more precise comparison for weakrefs, etc. */
+
+ return return_false_with_msg ("different references");
+}
+
+/* If cgraph edges E1 and E2 are indirect calls, verify that
+ ECF flags are the same. */
+
+bool sem_function::compare_edge_flags (cgraph_edge *e1, cgraph_edge *e2)
+{
+ if (e1->indirect_info && e2->indirect_info)
+ {
+ int e1_flags = e1->indirect_info->ecf_flags;
+ int e2_flags = e2->indirect_info->ecf_flags;
+
+ if (e1_flags != e2_flags)
+ return return_false_with_msg ("ICF flags are different");
+ }
+ else if (e1->indirect_info || e2->indirect_info)
+ return false;
+
+ return true;
+}
+
+/* Fast equality function based on knowledge known in WPA. */
+
+bool
+sem_function::equals_wpa (sem_item *item,
+ hash_map <symtab_node *, sem_item *> &ignored_nodes)
+{
+ gcc_assert (item->type == FUNC);
+
+ m_compared_func = static_cast<sem_function *> (item);
+
+ if (arg_types.length () != m_compared_func->arg_types.length ())
+ return return_false_with_msg ("different number of arguments");
+
+ /* Checking types of arguments. */
+ for (unsigned i = 0; i < arg_types.length (); i++)
+ {
+ /* This guard is here for function pointer with attributes (pr59927.c). */
+ if (!arg_types[i] || !m_compared_func->arg_types[i])
+ return return_false_with_msg ("NULL argument type");
+
+ /* Polymorphic comparison is executed just for non-leaf functions. */
+ bool is_not_leaf = get_node ()->callees != NULL;
+
+ if (!func_checker::compatible_types_p (arg_types[i],
+ m_compared_func->arg_types[i],
+ is_not_leaf, i == 0))
+ return return_false_with_msg ("argument type is different");
+ }
+
+ /* Result type checking. */
+ if (!func_checker::compatible_types_p (result_type,
+ m_compared_func->result_type))
+ return return_false_with_msg ("result types are different");
+
+ if (node->num_references () != item->node->num_references ())
+ return return_false_with_msg ("different number of references");
+
+ ipa_ref *ref = NULL, *ref2 = NULL;
+ for (unsigned i = 0; node->iterate_reference (i, ref); i++)
+ {
+ item->node->iterate_reference (i, ref2);
+
+ if (!compare_cgraph_references (ignored_nodes, ref->referred, ref2->referred))
+ return false;
+ }
+
+ cgraph_edge *e1 = dyn_cast <cgraph_node *> (node)->callees;
+ cgraph_edge *e2 = dyn_cast <cgraph_node *> (item->node)->callees;
+
+ while (e1 && e2)
+ {
+ if (!compare_cgraph_references (ignored_nodes, e1->callee, e2->callee))
+ return false;
+
+ e1 = e1->next_callee;
+ e2 = e2->next_callee;
+ }
+
+ if (e1 || e2)
+ return return_false_with_msg ("different number of edges");
+
+ return true;
+}
+
+/* Returns true if the item equals to ITEM given as argument. */
+
+bool
+sem_function::equals (sem_item *item,
+ hash_map <symtab_node *, sem_item *> &ignored_nodes)
+{
+ gcc_assert (item->type == FUNC);
+ bool eq = equals_private (item, ignored_nodes);
+
+ if (m_checker != NULL)
+ {
+ delete m_checker;
+ m_checker = NULL;
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "Equals called for:%s:%s (%u:%u) (%s:%s) with result: %s\n\n",
+ name(), item->name (), node->order, item->node->order, asm_name (),
+ item->asm_name (), eq ? "true" : "false");
+
+ return eq;
+}
+
+/* Processes function equality comparison. */
+
+bool
+sem_function::equals_private (sem_item *item,
+ hash_map <symtab_node *, sem_item *> &ignored_nodes)
+{
+ if (item->type != FUNC)
+ return false;
+
+ basic_block bb1, bb2;
+ edge e1, e2;
+ edge_iterator ei1, ei2;
+ int *bb_dict = NULL;
+ bool result = true;
+ tree arg1, arg2;
+
+ m_compared_func = static_cast<sem_function *> (item);
+
+ gcc_assert (decl != item->decl);
+
+ if (bb_sorted.length () != m_compared_func->bb_sorted.length ()
+ || edge_count != m_compared_func->edge_count
+ || cfg_checksum != m_compared_func->cfg_checksum)
+ return return_false ();
+
+ if (!equals_wpa (item, ignored_nodes))
+ return false;
+
+ /* Checking function arguments. */
+ tree decl1 = DECL_ATTRIBUTES (decl);
+ tree decl2 = DECL_ATTRIBUTES (m_compared_func->decl);
+
+ m_checker = new func_checker (decl, m_compared_func->decl,
+ compare_polymorphic_p (),
+ false,
+ &refs_set,
+ &m_compared_func->refs_set);
+ while (decl1)
+ {
+ if (decl2 == NULL)
+ return return_false ();
+
+ if (get_attribute_name (decl1) != get_attribute_name (decl2))
+ return return_false ();
+
+ tree attr_value1 = TREE_VALUE (decl1);
+ tree attr_value2 = TREE_VALUE (decl2);
+
+ if (attr_value1 && attr_value2)
+ {
+ bool ret = m_checker->compare_operand (TREE_VALUE (attr_value1),
+ TREE_VALUE (attr_value2));
+ if (!ret)
+ return return_false_with_msg ("attribute values are different");
+ }
+ else if (!attr_value1 && !attr_value2)
+ {}
+ else
+ return return_false ();
+
+ decl1 = TREE_CHAIN (decl1);
+ decl2 = TREE_CHAIN (decl2);
+ }
+
+ if (decl1 != decl2)
+ return return_false();
+
+
+ for (arg1 = DECL_ARGUMENTS (decl),
+ arg2 = DECL_ARGUMENTS (m_compared_func->decl);
+ arg1; arg1 = DECL_CHAIN (arg1), arg2 = DECL_CHAIN (arg2))
+ if (!m_checker->compare_decl (arg1, arg2))
+ return return_false ();
+
+ /* Fill-up label dictionary. */
+ for (unsigned i = 0; i < bb_sorted.length (); ++i)
+ {
+ m_checker->parse_labels (bb_sorted[i]);
+ m_checker->parse_labels (m_compared_func->bb_sorted[i]);
+ }
+
+ /* Checking all basic blocks. */
+ for (unsigned i = 0; i < bb_sorted.length (); ++i)
+ if(!m_checker->compare_bb (bb_sorted[i], m_compared_func->bb_sorted[i]))
+ return return_false();
+
+ dump_message ("All BBs are equal\n");
+
+ /* Basic block edges check. */
+ for (unsigned i = 0; i < bb_sorted.length (); ++i)
+ {
+ bb_dict = XNEWVEC (int, bb_sorted.length () + 2);
+ memset (bb_dict, -1, (bb_sorted.length () + 2) * sizeof (int));
+
+ bb1 = bb_sorted[i]->bb;
+ bb2 = m_compared_func->bb_sorted[i]->bb;
+
+ ei2 = ei_start (bb2->preds);
+
+ for (ei1 = ei_start (bb1->preds); ei_cond (ei1, &e1); ei_next (&ei1))
+ {
+ ei_cond (ei2, &e2);
+
+ if (e1->flags != e2->flags)
+ return return_false_with_msg ("flags comparison returns false");
+
+ if (!bb_dict_test (bb_dict, e1->src->index, e2->src->index))
+ return return_false_with_msg ("edge comparison returns false");
+
+ if (!bb_dict_test (bb_dict, e1->dest->index, e2->dest->index))
+ return return_false_with_msg ("BB comparison returns false");
+
+ if (!m_checker->compare_edge (e1, e2))
+ return return_false_with_msg ("edge comparison returns false");
+
+ ei_next (&ei2);
+ }
+ }
+
+ /* Basic block PHI nodes comparison. */
+ for (unsigned i = 0; i < bb_sorted.length (); i++)
+ if (!compare_phi_node (bb_sorted[i]->bb, m_compared_func->bb_sorted[i]->bb))
+ return return_false_with_msg ("PHI node comparison returns false");
+
+ return result;
+}
+
+/* Merges instance with an ALIAS_ITEM, where alias, thunk or redirection can
+ be applied. */
+bool
+sem_function::merge (sem_item *alias_item)
+{
+ gcc_assert (alias_item->type == FUNC);
+
+ sem_function *alias_func = static_cast<sem_function *> (alias_item);
+
+ cgraph_node *original = get_node ();
+ cgraph_node *local_original = original;
+ cgraph_node *alias = alias_func->get_node ();
+ bool original_address_matters;
+ bool alias_address_matters;
+
+ bool create_thunk = false;
+ bool create_alias = false;
+ bool redirect_callers = false;
+ bool original_discardable = false;
+
+ /* Do not attempt to mix functions from different user sections;
+ we do not know what user intends with those. */
+ if (((DECL_SECTION_NAME (original->decl) && !original->implicit_section)
+ || (DECL_SECTION_NAME (alias->decl) && !alias->implicit_section))
+ && DECL_SECTION_NAME (original->decl) != DECL_SECTION_NAME (alias->decl))
+ {
+ if (dump_file)
+ fprintf (dump_file,
+ "Not unifying; original and alias are in different sections.\n\n");
+ return false;
+ }
+
+ /* See if original is in a section that can be discarded if the main
+ symbol is not used. */
+ if (DECL_EXTERNAL (original->decl))
+ original_discardable = true;
+ if (original->resolution == LDPR_PREEMPTED_REG
+ || original->resolution == LDPR_PREEMPTED_IR)
+ original_discardable = true;
+ if (original->can_be_discarded_p ())
+ original_discardable = true;
+
+ /* See if original and/or alias address can be compared for equality. */
+ original_address_matters
+ = (!DECL_VIRTUAL_P (original->decl)
+ && (original->externally_visible
+ || original->address_taken_from_non_vtable_p ()));
+ alias_address_matters
+ = (!DECL_VIRTUAL_P (alias->decl)
+ && (alias->externally_visible
+ || alias->address_taken_from_non_vtable_p ()));
+
+ /* If alias and original can be compared for address equality, we need
+ to create a thunk. Also we can not create extra aliases into discardable
+ section (or we risk link failures when section is discarded). */
+ if ((original_address_matters
+ && alias_address_matters)
+ || original_discardable)
+ {
+ create_thunk = !stdarg_p (TREE_TYPE (alias->decl));
+ create_alias = false;
+ /* When both alias and original are not overwritable, we can save
+ the extra thunk wrapper for direct calls. */
+ redirect_callers
+ = (!original_discardable
+ && alias->get_availability () > AVAIL_INTERPOSABLE
+ && original->get_availability () > AVAIL_INTERPOSABLE);
+ }
+ else
+ {
+ create_alias = true;
+ create_thunk = false;
+ redirect_callers = false;
+ }
+
+ if (create_alias && DECL_COMDAT_GROUP (alias->decl))
+ {
+ create_alias = false;
+ create_thunk = true;
+ }
+
+ /* We want thunk to always jump to the local function body
+ unless the body is comdat and may be optimized out. */
+ if ((create_thunk || redirect_callers)
+ && (!original_discardable
+ || (DECL_COMDAT_GROUP (original->decl)
+ && (DECL_COMDAT_GROUP (original->decl)
+ == DECL_COMDAT_GROUP (alias->decl)))))
+ local_original
+ = dyn_cast <cgraph_node *> (original->noninterposable_alias ());
+
+ if (redirect_callers)
+ {
+ /* If alias is non-overwritable then
+ all direct calls are safe to be redirected to the original. */
+ bool redirected = false;
+ while (alias->callers)
+ {
+ cgraph_edge *e = alias->callers;
+ e->redirect_callee (local_original);
+ push_cfun (DECL_STRUCT_FUNCTION (e->caller->decl));
+
+ if (e->call_stmt)
+ e->redirect_call_stmt_to_callee ();
+
+ pop_cfun ();
+ redirected = true;
+ }
+
+ alias->icf_merged = true;
+
+ /* The alias function is removed if symbol address
+ does not matter. */
+ if (!alias_address_matters)
+ alias->remove ();
+
+ if (dump_file && redirected)
+ fprintf (dump_file, "Callgraph local calls have been redirected.\n\n");
+ }
+ /* If the condtion above is not met, we are lucky and can turn the
+ function into real alias. */
+ else if (create_alias)
+ {
+ alias->icf_merged = true;
+
+ /* Remove the function's body. */
+ ipa_merge_profiles (original, alias);
+ alias->release_body (true);
+ alias->reset ();
+
+ /* Create the alias. */
+ cgraph_node::create_alias (alias_func->decl, decl);
+ alias->resolve_alias (original);
+
+ if (dump_file)
+ fprintf (dump_file, "Callgraph alias has been created.\n\n");
+ }
+ else if (create_thunk)
+ {
+ if (DECL_COMDAT_GROUP (alias->decl))
+ {
+ if (dump_file)
+ fprintf (dump_file, "Callgraph thunk cannot be created because of COMDAT\n");
+
+ return 0;
+ }
+
+ alias->icf_merged = true;
+ ipa_merge_profiles (local_original, alias);
+ alias->create_wrapper (local_original);
+
+ if (dump_file)
+ fprintf (dump_file, "Callgraph thunk has been created.\n\n");
+ }
+ else if (dump_file)
+ fprintf (dump_file, "Callgraph merge operation cannot be performed.\n\n");
+
+ return true;
+}
+
+/* Semantic item initialization function. */
+
+void
+sem_function::init (void)
+{
+ if (in_lto_p)
+ get_node ()->get_body ();
+
+ tree fndecl = node->decl;
+ function *func = DECL_STRUCT_FUNCTION (fndecl);
+
+ gcc_assert (func);
+ gcc_assert (SSANAMES (func));
+
+ ssa_names_size = SSANAMES (func)->length ();
+ node = node;
+
+ decl = fndecl;
+ region_tree = func->eh->region_tree;
+
+ /* iterating all function arguments. */
+ arg_count = count_formal_params (fndecl);
+
+ edge_count = n_edges_for_fn (func);
+ cfg_checksum = coverage_compute_cfg_checksum (func);
+
+ inchash::hash hstate;
+
+ basic_block bb;
+ FOR_EACH_BB_FN (bb, func)
+ {
+ unsigned nondbg_stmt_count = 0;
+
+ edge e;
+ for (edge_iterator ei = ei_start (bb->preds); ei_cond (ei, &e); ei_next (&ei))
+ cfg_checksum = iterative_hash_host_wide_int (e->flags,
+ cfg_checksum);
+
+ for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi);
+ gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+
+ if (gimple_code (stmt) != GIMPLE_DEBUG)
+ {
+ hash_stmt (&hstate, stmt);
+ nondbg_stmt_count++;
+ }
+ }
+
+ gcode_hash = hstate.end ();
+ bb_sizes.safe_push (nondbg_stmt_count);
+
+ /* Inserting basic block to hash table. */
+ sem_bb *semantic_bb = new sem_bb (bb, nondbg_stmt_count,
+ EDGE_COUNT (bb->preds) + EDGE_COUNT (bb->succs));
+
+ bb_sorted.safe_push (semantic_bb);
+ }
+
+ parse_tree_args ();
+}
+
+/* Improve accumulated hash for HSTATE based on a gimple statement STMT. */
+
+void
+sem_function::hash_stmt (inchash::hash *hstate, gimple stmt)
+{
+ enum gimple_code code = gimple_code (stmt);
+
+ hstate->add_int (code);
+
+ if (code == GIMPLE_CALL)
+ {
+ /* Checking of argument. */
+ for (unsigned i = 0; i < gimple_call_num_args (stmt); ++i)
+ {
+ tree argument = gimple_call_arg (stmt, i);
+
+ switch (TREE_CODE (argument))
+ {
+ case INTEGER_CST:
+ if (tree_fits_shwi_p (argument))
+ hstate->add_wide_int (tree_to_shwi (argument));
+ else if (tree_fits_uhwi_p (argument))
+ hstate->add_wide_int (tree_to_uhwi (argument));
+ break;
+ case REAL_CST:
+ REAL_VALUE_TYPE c;
+ HOST_WIDE_INT n;
+
+ c = TREE_REAL_CST (argument);
+ n = real_to_integer (&c);
+
+ hstate->add_wide_int (n);
+ break;
+ case ADDR_EXPR:
+ {
+ tree addr_operand = TREE_OPERAND (argument, 0);
+
+ if (TREE_CODE (addr_operand) == STRING_CST)
+ hstate->add (TREE_STRING_POINTER (addr_operand),
+ TREE_STRING_LENGTH (addr_operand));
+ break;
+ }
+ default:
+ break;
+ }
+ }
+ }
+}
+
+
+/* Return true if polymorphic comparison must be processed. */
+
+bool
+sem_function::compare_polymorphic_p (void)
+{
+ return get_node ()->callees != NULL
+ || m_compared_func->get_node ()->callees != NULL;
+}
+
+/* For a given call graph NODE, the function constructs new
+ semantic function item. */
+
+sem_function *
+sem_function::parse (cgraph_node *node, bitmap_obstack *stack)
+{
+ tree fndecl = node->decl;
+ function *func = DECL_STRUCT_FUNCTION (fndecl);
+
+ /* TODO: add support for thunks and aliases. */
+
+ if (!func || !node->has_gimple_body_p ())
+ return NULL;
+
+ if (lookup_attribute_by_prefix ("omp ", DECL_ATTRIBUTES (node->decl)) != NULL)
+ return NULL;
+
+ sem_function *f = new sem_function (node, 0, stack);
+
+ f->init ();
+
+ return f;
+}
+
+/* Parses function arguments and result type. */
+
+void
+sem_function::parse_tree_args (void)
+{
+ tree result;
+
+ if (arg_types.exists ())
+ arg_types.release ();
+
+ arg_types.create (4);
+ tree fnargs = DECL_ARGUMENTS (decl);
+
+ for (tree parm = fnargs; parm; parm = DECL_CHAIN (parm))
+ arg_types.safe_push (DECL_ARG_TYPE (parm));
+
+ /* Function result type. */
+ result = DECL_RESULT (decl);
+ result_type = result ? TREE_TYPE (result) : NULL;
+
+ /* During WPA, we can get arguments by following method. */
+ if (!fnargs)
+ {
+ tree type = TYPE_ARG_TYPES (TREE_TYPE (decl));
+ for (tree parm = type; parm; parm = TREE_CHAIN (parm))
+ arg_types.safe_push (TYPE_CANONICAL (TREE_VALUE (parm)));
+
+ result_type = TREE_TYPE (TREE_TYPE (decl));
+ }
+}
+
+/* For given basic blocks BB1 and BB2 (from functions FUNC1 and FUNC),
+ return true if phi nodes are semantically equivalent in these blocks . */
+
+bool
+sem_function::compare_phi_node (basic_block bb1, basic_block bb2)
+{
+ gimple_stmt_iterator si1, si2;
+ gimple phi1, phi2;
+ unsigned size1, size2, i;
+ tree t1, t2;
+ edge e1, e2;
+
+ gcc_assert (bb1 != NULL);
+ gcc_assert (bb2 != NULL);
+
+ si2 = gsi_start_phis (bb2);
+ for (si1 = gsi_start_phis (bb1); !gsi_end_p (si1);
+ gsi_next (&si1))
+ {
+ gsi_next_nonvirtual_phi (&si1);
+ gsi_next_nonvirtual_phi (&si2);
+
+ if (gsi_end_p (si1) && gsi_end_p (si2))
+ break;
+
+ if (gsi_end_p (si1) || gsi_end_p (si2))
+ return return_false();
+
+ phi1 = gsi_stmt (si1);
+ phi2 = gsi_stmt (si2);
+
+ size1 = gimple_phi_num_args (phi1);
+ size2 = gimple_phi_num_args (phi2);
+
+ if (size1 != size2)
+ return return_false ();
+
+ for (i = 0; i < size1; ++i)
+ {
+ t1 = gimple_phi_arg (phi1, i)->def;
+ t2 = gimple_phi_arg (phi2, i)->def;
+
+ if (!m_checker->compare_operand (t1, t2))
+ return return_false ();
+
+ e1 = gimple_phi_arg_edge (phi1, i);
+ e2 = gimple_phi_arg_edge (phi2, i);
+
+ if (!m_checker->compare_edge (e1, e2))
+ return return_false ();
+ }
+
+ gsi_next (&si2);
+ }
+
+ return true;
+}
+
+/* Returns true if tree T can be compared as a handled component. */
+
+bool
+sem_function::icf_handled_component_p (tree t)
+{
+ tree_code tc = TREE_CODE (t);
+
+ return ((handled_component_p (t))
+ || tc == ADDR_EXPR || tc == MEM_REF || tc == REALPART_EXPR
+ || tc == IMAGPART_EXPR || tc == OBJ_TYPE_REF);
+}
+
+/* Basic blocks dictionary BB_DICT returns true if SOURCE index BB
+ corresponds to TARGET. */
+
+bool
+sem_function::bb_dict_test (int* bb_dict, int source, int target)
+{
+ if (bb_dict[source] == -1)
+ {
+ bb_dict[source] = target;
+ return true;
+ }
+ else
+ return bb_dict[source] == target;
+}
+
+/* Iterates all tree types in T1 and T2 and returns true if all types
+ are compatible. If COMPARE_POLYMORPHIC is set to true,
+ more strict comparison is executed. */
+
+bool
+sem_function::compare_type_list (tree t1, tree t2, bool compare_polymorphic)
+{
+ tree tv1, tv2;
+ tree_code tc1, tc2;
+
+ if (!t1 && !t2)
+ return true;
+
+ while (t1 != NULL && t2 != NULL)
+ {
+ tv1 = TREE_VALUE (t1);
+ tv2 = TREE_VALUE (t2);
+
+ tc1 = TREE_CODE (tv1);
+ tc2 = TREE_CODE (tv2);
+
+ if (tc1 == NOP_EXPR && tc2 == NOP_EXPR)
+ {}
+ else if (tc1 == NOP_EXPR || tc2 == NOP_EXPR)
+ return false;
+ else if (!func_checker::compatible_types_p (tv1, tv2, compare_polymorphic))
+ return false;
+
+ t1 = TREE_CHAIN (t1);
+ t2 = TREE_CHAIN (t2);
+ }
+
+ return !(t1 || t2);
+}
+
+
+/* Semantic variable constructor that uses STACK as bitmap memory stack. */
+
+sem_variable::sem_variable (bitmap_obstack *stack): sem_item (VAR, stack)
+{
+}
+
+/* Constructor based on varpool node _NODE with computed hash _HASH.
+ Bitmap STACK is used for memory allocation. */
+
+sem_variable::sem_variable (varpool_node *node, hashval_t _hash,
+ bitmap_obstack *stack): sem_item(VAR,
+ node, _hash, stack)
+{
+ gcc_checking_assert (node);
+ gcc_checking_assert (get_node ());
+}
+
+/* Returns true if the item equals to ITEM given as argument. */
+
+bool
+sem_variable::equals (sem_item *item,
+ hash_map <symtab_node *, sem_item *> & ARG_UNUSED (ignored_nodes))
+{
+ gcc_assert (item->type == VAR);
+
+ sem_variable *v = static_cast<sem_variable *>(item);
+
+ if (!ctor || !v->ctor)
+ return return_false_with_msg ("ctor is missing for semantic variable");
+
+ return sem_variable::equals (ctor, v->ctor);
+}
+
+/* Compares trees T1 and T2 for semantic equality. */
+
+bool
+sem_variable::equals (tree t1, tree t2)
+{
+ tree_code tc1 = TREE_CODE (t1);
+ tree_code tc2 = TREE_CODE (t2);
+
+ if (tc1 != tc2)
+ return false;
+
+ switch (tc1)
+ {
+ case CONSTRUCTOR:
+ {
+ unsigned len1 = vec_safe_length (CONSTRUCTOR_ELTS (t1));
+ unsigned len2 = vec_safe_length (CONSTRUCTOR_ELTS (t2));
+
+ if (len1 != len2)
+ return false;
+
+ for (unsigned i = 0; i < len1; i++)
+ if (!sem_variable::equals (CONSTRUCTOR_ELT (t1, i)->value,
+ CONSTRUCTOR_ELT (t2, i)->value)
+ || CONSTRUCTOR_ELT (t1, i)->index != CONSTRUCTOR_ELT (t2, i)->index)
+ return false;
+
+ return true;
+ }
+ case MEM_REF:
+ {
+ tree x1 = TREE_OPERAND (t1, 0);
+ tree x2 = TREE_OPERAND (t2, 0);
+ tree y1 = TREE_OPERAND (t1, 1);
+ tree y2 = TREE_OPERAND (t2, 1);
+
+ if (!func_checker::compatible_types_p (TREE_TYPE (x1), TREE_TYPE (x2),
+ true))
+ return return_false ();
+
+ /* Type of the offset on MEM_REF does not matter. */
+ return sem_variable::equals (x1, x2)
+ && wi::to_offset (y1) == wi::to_offset (y2);
+ }
+ case NOP_EXPR:
+ case ADDR_EXPR:
+ {
+ tree op1 = TREE_OPERAND (t1, 0);
+ tree op2 = TREE_OPERAND (t2, 0);
+ return sem_variable::equals (op1, op2);
+ }
+ case FUNCTION_DECL:
+ case VAR_DECL:
+ case FIELD_DECL:
+ case LABEL_DECL:
+ return t1 == t2;
+ case INTEGER_CST:
+ return func_checker::compatible_types_p (TREE_TYPE (t1), TREE_TYPE (t2),
+ true)
+ && wi::to_offset (t1) == wi::to_offset (t2);
+ case STRING_CST:
+ case REAL_CST:
+ case COMPLEX_CST:
+ return operand_equal_p (t1, t2, OEP_ONLY_CONST);
+ case COMPONENT_REF:
+ case ARRAY_REF:
+ case POINTER_PLUS_EXPR:
+ {
+ tree x1 = TREE_OPERAND (t1, 0);
+ tree x2 = TREE_OPERAND (t2, 0);
+ tree y1 = TREE_OPERAND (t1, 1);
+ tree y2 = TREE_OPERAND (t2, 1);
+
+ return sem_variable::equals (x1, x2) && sem_variable::equals (y1, y2);
+ }
+ case ERROR_MARK:
+ return return_false_with_msg ("ERROR_MARK");
+ default:
+ return return_false_with_msg ("Unknown TREE code reached");
+ }
+}
+
+/* Parser function that visits a varpool NODE. */
+
+sem_variable *
+sem_variable::parse (varpool_node *node, bitmap_obstack *stack)
+{
+ tree decl = node->decl;
+
+ bool readonly = TYPE_P (decl) ? TYPE_READONLY (decl) : TREE_READONLY (decl);
+ bool can_handle = readonly && (DECL_VIRTUAL_P (decl)
+ || !TREE_ADDRESSABLE (decl));
+
+ if (!can_handle)
+ return NULL;
+
+ tree ctor = ctor_for_folding (decl);
+ if (!ctor)
+ return NULL;
+
+ sem_variable *v = new sem_variable (node, 0, stack);
+
+ v->init ();
+
+ return v;
+}
+
+/* References independent hash function. */
+
+hashval_t
+sem_variable::get_hash (void)
+{
+ if (hash)
+ return hash;
+
+ inchash::hash hstate;
+
+ hstate.add_int (456346417);
+ hstate.add_int (TREE_CODE (ctor));
+
+ if (TREE_CODE (ctor) == CONSTRUCTOR)
+ {
+ unsigned length = vec_safe_length (CONSTRUCTOR_ELTS (ctor));
+ hstate.add_int (length);
+ }
+
+ hash = hstate.end ();
+
+ return hash;
+}
+
+/* Merges instance with an ALIAS_ITEM, where alias, thunk or redirection can
+ be applied. */
+
+bool
+sem_variable::merge (sem_item *alias_item)
+{
+ gcc_assert (alias_item->type == VAR);
+
+ sem_variable *alias_var = static_cast<sem_variable *> (alias_item);
+
+ varpool_node *original = get_node ();
+ varpool_node *alias = alias_var->get_node ();
+ bool original_discardable = false;
+
+ /* See if original is in a section that can be discarded if the main
+ symbol is not used. */
+ if (DECL_EXTERNAL (original->decl))
+ original_discardable = true;
+ if (original->resolution == LDPR_PREEMPTED_REG
+ || original->resolution == LDPR_PREEMPTED_IR)
+ original_discardable = true;
+ if (original->can_be_discarded_p ())
+ original_discardable = true;
+
+ gcc_assert (!TREE_ASM_WRITTEN (alias->decl));
+
+ if (original_discardable || DECL_EXTERNAL (alias_var->decl) ||
+ !compare_sections (alias_var))
+ {
+ if (dump_file)
+ fprintf (dump_file, "Varpool alias cannot be created\n\n");
+
+ return false;
+ }
+ else
+ {
+ // alias cycle creation check
+ varpool_node *n = original;
+
+ while (n->alias)
+ {
+ n = n->get_alias_target ();
+ if (n == alias)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Varpool alias cannot be created (alias cycle).\n\n");
+
+ return false;
+ }
+ }
+
+ alias->analyzed = false;
+
+ DECL_INITIAL (alias->decl) = NULL;
+ alias->remove_all_references ();
+
+ varpool_node::create_alias (alias_var->decl, decl);
+ alias->resolve_alias (original);
+
+ if (dump_file)
+ fprintf (dump_file, "Varpool alias has been created.\n\n");
+
+ return true;
+ }
+}
+
+bool
+sem_variable::compare_sections (sem_variable *alias)
+{
+ const char *source = node->get_section ();
+ const char *target = alias->node->get_section();
+
+ if (source == NULL && target == NULL)
+ return true;
+ else if(!source || !target)
+ return false;
+ else
+ return strcmp (source, target) == 0;
+}
+
+/* Dump symbol to FILE. */
+
+void
+sem_variable::dump_to_file (FILE *file)
+{
+ gcc_assert (file);
+
+ print_node (file, "", decl, 0);
+ fprintf (file, "\n\n");
+}
+
+/* Iterates though a constructor and identifies tree references
+ we are interested in semantic function equality. */
+
+void
+sem_variable::parse_tree_refs (tree t)
+{
+ switch (TREE_CODE (t))
+ {
+ case CONSTRUCTOR:
+ {
+ unsigned length = vec_safe_length (CONSTRUCTOR_ELTS (t));
+
+ for (unsigned i = 0; i < length; i++)
+ parse_tree_refs(CONSTRUCTOR_ELT (t, i)->value);
+
+ break;
+ }
+ case NOP_EXPR:
+ case ADDR_EXPR:
+ {
+ tree op = TREE_OPERAND (t, 0);
+ parse_tree_refs (op);
+ break;
+ }
+ case FUNCTION_DECL:
+ {
+ tree_refs.safe_push (t);
+ break;
+ }
+ default:
+ break;
+ }
+}
+
+unsigned int sem_item_optimizer::class_id = 0;
+
+sem_item_optimizer::sem_item_optimizer (): worklist (0), m_classes (0),
+ m_classes_count (0), m_cgraph_node_hooks (NULL), m_varpool_node_hooks (NULL)
+{
+ m_items.create (0);
+ bitmap_obstack_initialize (&m_bmstack);
+}
+
+sem_item_optimizer::~sem_item_optimizer ()
+{
+ for (unsigned int i = 0; i < m_items.length (); i++)
+ delete m_items[i];
+
+ for (hash_table<congruence_class_group_hash>::iterator it = m_classes.begin ();
+ it != m_classes.end (); ++it)
+ {
+ for (unsigned int i = 0; i < (*it)->classes.length (); i++)
+ delete (*it)->classes[i];
+
+ (*it)->classes.release ();
+ }
+
+ m_items.release ();
+
+ bitmap_obstack_release (&m_bmstack);
+}
+
+/* Write IPA ICF summary for symbols. */
+
+void
+sem_item_optimizer::write_summary (void)
+{
+ unsigned int count = 0;
+
+ output_block *ob = create_output_block (LTO_section_ipa_icf);
+ lto_symtab_encoder_t encoder = ob->decl_state->symtab_node_encoder;
+ ob->symbol = NULL;
+
+ /* Calculate number of symbols to be serialized. */
+ for (lto_symtab_encoder_iterator lsei = lsei_start_in_partition (encoder);
+ !lsei_end_p (lsei);
+ lsei_next_in_partition (&lsei))
+ {
+ symtab_node *node = lsei_node (lsei);
+
+ if (m_symtab_node_map.get (node))
+ count++;
+ }
+
+ streamer_write_uhwi (ob, count);
+
+ /* Process all of the symbols. */
+ for (lto_symtab_encoder_iterator lsei = lsei_start_in_partition (encoder);
+ !lsei_end_p (lsei);
+ lsei_next_in_partition (&lsei))
+ {
+ symtab_node *node = lsei_node (lsei);
+
+ sem_item **item = m_symtab_node_map.get (node);
+
+ if (item && *item)
+ {
+ int node_ref = lto_symtab_encoder_encode (encoder, node);
+ streamer_write_uhwi_stream (ob->main_stream, node_ref);
+
+ streamer_write_uhwi (ob, (*item)->get_hash ());
+ }
+ }
+
+ streamer_write_char_stream (ob->main_stream, 0);
+ produce_asm (ob, NULL);
+ destroy_output_block (ob);
+}
+
+/* Reads a section from LTO stream file FILE_DATA. Input block for DATA
+ contains LEN bytes. */
+
+void
+sem_item_optimizer::read_section (lto_file_decl_data *file_data,
+ const char *data, size_t len)
+{
+ const lto_function_header *header =
+ (const lto_function_header *) data;
+ const int cfg_offset = sizeof (lto_function_header);
+ const int main_offset = cfg_offset + header->cfg_size;
+ const int string_offset = main_offset + header->main_size;
+ data_in *data_in;
+ unsigned int i;
+ unsigned int count;
+
+ lto_input_block ib_main ((const char *) data + main_offset, 0,
+ header->main_size);
+
+ data_in =
+ lto_data_in_create (file_data, (const char *) data + string_offset,
+ header->string_size, vNULL);
+
+ count = streamer_read_uhwi (&ib_main);
+
+ for (i = 0; i < count; i++)
+ {
+ unsigned int index;
+ symtab_node *node;
+ lto_symtab_encoder_t encoder;
+
+ index = streamer_read_uhwi (&ib_main);
+ encoder = file_data->symtab_node_encoder;
+ node = lto_symtab_encoder_deref (encoder, index);
+
+ hashval_t hash = streamer_read_uhwi (&ib_main);
+
+ gcc_assert (node->definition);
+
+ if (dump_file)
+ fprintf (dump_file, "Symbol added:%s (tree: %p, uid:%u)\n", node->asm_name (),
+ (void *) node->decl, node->order);
+
+ if (is_a<cgraph_node *> (node))
+ {
+ cgraph_node *cnode = dyn_cast <cgraph_node *> (node);
+
+ m_items.safe_push (new sem_function (cnode, hash, &m_bmstack));
+ }
+ else
+ {
+ varpool_node *vnode = dyn_cast <varpool_node *> (node);
+
+ m_items.safe_push (new sem_variable (vnode, hash, &m_bmstack));
+ }
+ }
+
+ lto_free_section_data (file_data, LTO_section_ipa_icf, NULL, data,
+ len);
+ lto_data_in_delete (data_in);
+}
+
+/* Read IPA IPA ICF summary for symbols. */
+
+void
+sem_item_optimizer::read_summary (void)
+{
+ lto_file_decl_data **file_data_vec = lto_get_file_decl_data ();
+ lto_file_decl_data *file_data;
+ unsigned int j = 0;
+
+ while ((file_data = file_data_vec[j++]))
+ {
+ size_t len;
+ const char *data = lto_get_section_data (file_data,
+ LTO_section_ipa_icf, NULL, &len);
+
+ if (data)
+ read_section (file_data, data, len);
+ }
+}
+
+/* Register callgraph and varpool hooks. */
+
+void
+sem_item_optimizer::register_hooks (void)
+{
+ m_cgraph_node_hooks = symtab->add_cgraph_removal_hook
+ (&sem_item_optimizer::cgraph_removal_hook, this);
+
+ m_varpool_node_hooks = symtab->add_varpool_removal_hook
+ (&sem_item_optimizer::varpool_removal_hook, this);
+}
+
+/* Unregister callgraph and varpool hooks. */
+
+void
+sem_item_optimizer::unregister_hooks (void)
+{
+ if (m_cgraph_node_hooks)
+ symtab->remove_cgraph_removal_hook (m_cgraph_node_hooks);
+
+ if (m_varpool_node_hooks)
+ symtab->remove_varpool_removal_hook (m_varpool_node_hooks);
+}
+
+/* Adds a CLS to hashtable associated by hash value. */
+
+void
+sem_item_optimizer::add_class (congruence_class *cls)
+{
+ gcc_assert (cls->members.length ());
+
+ congruence_class_group *group = get_group_by_hash (
+ cls->members[0]->get_hash (),
+ cls->members[0]->type);
+ group->classes.safe_push (cls);
+}
+
+/* Gets a congruence class group based on given HASH value and TYPE. */
+
+congruence_class_group *
+sem_item_optimizer::get_group_by_hash (hashval_t hash, sem_item_type type)
+{
+ congruence_class_group *item = XNEW (congruence_class_group);
+ item->hash = hash;
+ item->type = type;
+
+ congruence_class_group **slot = m_classes.find_slot (item, INSERT);
+
+ if (*slot)
+ free (item);
+ else
+ {
+ item->classes.create (1);
+ *slot = item;
+ }
+
+ return *slot;
+}
+
+/* Callgraph removal hook called for a NODE with a custom DATA. */
+
+void
+sem_item_optimizer::cgraph_removal_hook (cgraph_node *node, void *data)
+{
+ sem_item_optimizer *optimizer = (sem_item_optimizer *) data;
+ optimizer->remove_symtab_node (node);
+}
+
+/* Varpool removal hook called for a NODE with a custom DATA. */
+
+void
+sem_item_optimizer::varpool_removal_hook (varpool_node *node, void *data)
+{
+ sem_item_optimizer *optimizer = (sem_item_optimizer *) data;
+ optimizer->remove_symtab_node (node);
+}
+
+/* Remove symtab NODE triggered by symtab removal hooks. */
+
+void
+sem_item_optimizer::remove_symtab_node (symtab_node *node)
+{
+ gcc_assert (!m_classes.elements());
+
+ m_removed_items_set.add (node);
+}
+
+void
+sem_item_optimizer::remove_item (sem_item *item)
+{
+ if (m_symtab_node_map.get (item->node))
+ m_symtab_node_map.remove (item->node);
+ delete item;
+}
+
+/* Removes all callgraph and varpool nodes that are marked by symtab
+ as deleted. */
+
+void
+sem_item_optimizer::filter_removed_items (void)
+{
+ auto_vec <sem_item *> filtered;
+
+ for (unsigned int i = 0; i < m_items.length(); i++)
+ {
+ sem_item *item = m_items[i];
+
+ if (!flag_ipa_icf_functions && item->type == FUNC)
+ {
+ remove_item (item);
+ continue;
+ }
+
+ if (!flag_ipa_icf_variables && item->type == VAR)
+ {
+ remove_item (item);
+ continue;
+ }
+
+ bool no_body_function = false;
+
+ if (item->type == FUNC)
+ {
+ cgraph_node *cnode = static_cast <sem_function *>(item)->get_node ();
+
+ no_body_function = in_lto_p && (cnode->alias || cnode->body_removed);
+ }
+
+ if(!m_removed_items_set.contains (m_items[i]->node)
+ && !no_body_function)
+ {
+ if (item->type == VAR || (!DECL_CXX_CONSTRUCTOR_P (item->decl)
+ && !DECL_CXX_DESTRUCTOR_P (item->decl)))
+ {
+ filtered.safe_push (m_items[i]);
+ continue;
+ }
+ }
+
+ remove_item (item);
+ }
+
+ /* Clean-up of released semantic items. */
+
+ m_items.release ();
+ for (unsigned int i = 0; i < filtered.length(); i++)
+ m_items.safe_push (filtered[i]);
+}
+
+/* Optimizer entry point. */
+
+void
+sem_item_optimizer::execute (void)
+{
+ filter_removed_items ();
+ build_hash_based_classes ();
+
+ if (dump_file)
+ fprintf (dump_file, "Dump after hash based groups\n");
+ dump_cong_classes ();
+
+ for (unsigned int i = 0; i < m_items.length(); i++)
+ m_items[i]->init_wpa ();
+
+ build_graph ();
+
+ subdivide_classes_by_equality (true);
+
+ if (dump_file)
+ fprintf (dump_file, "Dump after WPA based types groups\n");
+
+ dump_cong_classes ();
+
+ process_cong_reduction ();
+ verify_classes ();
+
+ if (dump_file)
+ fprintf (dump_file, "Dump after callgraph-based congruence reduction\n");
+
+ dump_cong_classes ();
+
+ parse_nonsingleton_classes ();
+ subdivide_classes_by_equality ();
+
+ if (dump_file)
+ fprintf (dump_file, "Dump after full equality comparison of groups\n");
+
+ dump_cong_classes ();
+
+ unsigned int prev_class_count = m_classes_count;
+
+ process_cong_reduction ();
+ dump_cong_classes ();
+ verify_classes ();
+ merge_classes (prev_class_count);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ symtab_node::dump_table (dump_file);
+}
+
+/* Function responsible for visiting all potential functions and
+ read-only variables that can be merged. */
+
+void
+sem_item_optimizer::parse_funcs_and_vars (void)
+{
+ cgraph_node *cnode;
+
+ if (flag_ipa_icf_functions)
+ FOR_EACH_DEFINED_FUNCTION (cnode)
+ {
+ sem_function *f = sem_function::parse (cnode, &m_bmstack);
+ if (f)
+ {
+ m_items.safe_push (f);
+ m_symtab_node_map.put (cnode, f);
+
+ if (dump_file)
+ fprintf (dump_file, "Parsed function:%s\n", f->asm_name ());
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ f->dump_to_file (dump_file);
+ }
+ else if (dump_file)
+ fprintf (dump_file, "Not parsed function:%s\n", cnode->asm_name ());
+ }
+
+ varpool_node *vnode;
+
+ if (flag_ipa_icf_variables)
+ FOR_EACH_DEFINED_VARIABLE (vnode)
+ {
+ sem_variable *v = sem_variable::parse (vnode, &m_bmstack);
+
+ if (v)
+ {
+ m_items.safe_push (v);
+ m_symtab_node_map.put (vnode, v);
+ }
+ }
+}
+
+/* Makes pairing between a congruence class CLS and semantic ITEM. */
+
+void
+sem_item_optimizer::add_item_to_class (congruence_class *cls, sem_item *item)
+{
+ item->index_in_class = cls->members.length ();
+ cls->members.safe_push (item);
+ item->cls = cls;
+}
+
+/* Congruence classes are built by hash value. */
+
+void
+sem_item_optimizer::build_hash_based_classes (void)
+{
+ for (unsigned i = 0; i < m_items.length (); i++)
+ {
+ sem_item *item = m_items[i];
+
+ congruence_class_group *group = get_group_by_hash (item->get_hash (),
+ item->type);
+
+ if (!group->classes.length ())
+ {
+ m_classes_count++;
+ group->classes.safe_push (new congruence_class (class_id++));
+ }
+
+ add_item_to_class (group->classes[0], item);
+ }
+}
+
+/* Build references according to call graph. */
+
+void
+sem_item_optimizer::build_graph (void)
+{
+ for (unsigned i = 0; i < m_items.length (); i++)
+ {
+ sem_item *item = m_items[i];
+ m_symtab_node_map.put (item->node, item);
+ }
+
+ for (unsigned i = 0; i < m_items.length (); i++)
+ {
+ sem_item *item = m_items[i];
+
+ if (item->type == FUNC)
+ {
+ cgraph_node *cnode = dyn_cast <cgraph_node *> (item->node);
+
+ cgraph_edge *e = cnode->callees;
+ while (e)
+ {
+ sem_item **slot = m_symtab_node_map.get (e->callee);
+ if (slot)
+ item->add_reference (*slot);
+
+ e = e->next_callee;
+ }
+ }
+
+ ipa_ref *ref = NULL;
+ for (unsigned i = 0; item->node->iterate_reference (i, ref); i++)
+ {
+ sem_item **slot = m_symtab_node_map.get (ref->referred);
+ if (slot)
+ item->add_reference (*slot);
+ }
+ }
+}
+
+/* Semantic items in classes having more than one element and initialized.
+ In case of WPA, we load function body. */
+
+void
+sem_item_optimizer::parse_nonsingleton_classes (void)
+{
+ unsigned int init_called_count = 0;
+
+ for (unsigned i = 0; i < m_items.length (); i++)
+ if (m_items[i]->cls->members.length () > 1)
+ {
+ m_items[i]->init ();
+ init_called_count++;
+ }
+
+ if (dump_file)
+ fprintf (dump_file, "Init called for %u items (%.2f%%).\n", init_called_count,
+ 100.0f * init_called_count / m_items.length ());
+}
+
+/* Equality function for semantic items is used to subdivide existing
+ classes. If IN_WPA, fast equality function is invoked. */
+
+void
+sem_item_optimizer::subdivide_classes_by_equality (bool in_wpa)
+{
+ for (hash_table <congruence_class_group_hash>::iterator it = m_classes.begin ();
+ it != m_classes.end (); ++it)
+ {
+ unsigned int class_count = (*it)->classes.length ();
+
+ for (unsigned i = 0; i < class_count; i++)
+ {
+ congruence_class *c = (*it)->classes [i];
+
+ if (c->members.length() > 1)
+ {
+ auto_vec <sem_item *> new_vector;
+
+ sem_item *first = c->members[0];
+ new_vector.safe_push (first);
+
+ unsigned class_split_first = (*it)->classes.length ();
+
+ for (unsigned j = 1; j < c->members.length (); j++)
+ {
+ sem_item *item = c->members[j];
+
+ bool equals = in_wpa ? first->equals_wpa (item,
+ m_symtab_node_map) : first->equals (item, m_symtab_node_map);
+
+ if (equals)
+ new_vector.safe_push (item);
+ else
+ {
+ bool integrated = false;
+
+ for (unsigned k = class_split_first; k < (*it)->classes.length (); k++)
+ {
+ sem_item *x = (*it)->classes[k]->members[0];
+ bool equals = in_wpa ? x->equals_wpa (item,
+ m_symtab_node_map) : x->equals (item, m_symtab_node_map);
+
+ if (equals)
+ {
+ integrated = true;
+ add_item_to_class ((*it)->classes[k], item);
+
+ break;
+ }
+ }
+
+ if (!integrated)
+ {
+ congruence_class *c = new congruence_class (class_id++);
+ m_classes_count++;
+ add_item_to_class (c, item);
+
+ (*it)->classes.safe_push (c);
+ }
+ }
+ }
+
+ // we replace newly created new_vector for the class we've just splitted
+ c->members.release ();
+ c->members.create (new_vector.length ());
+
+ for (unsigned int j = 0; j < new_vector.length (); j++)
+ add_item_to_class (c, new_vector[j]);
+ }
+ }
+ }
+
+ verify_classes ();
+}
+
+/* Verify congruence classes if checking is enabled. */
+
+void
+sem_item_optimizer::verify_classes (void)
+{
+#if ENABLE_CHECKING
+ for (hash_table <congruence_class_group_hash>::iterator it = m_classes.begin ();
+ it != m_classes.end (); ++it)
+ {
+ for (unsigned int i = 0; i < (*it)->classes.length (); i++)
+ {
+ congruence_class *cls = (*it)->classes[i];
+
+ gcc_checking_assert (cls);
+ gcc_checking_assert (cls->members.length () > 0);
+
+ for (unsigned int j = 0; j < cls->members.length (); j++)
+ {
+ sem_item *item = cls->members[j];
+
+ gcc_checking_assert (item);
+ gcc_checking_assert (item->cls == cls);
+
+ for (unsigned k = 0; k < item->usages.length (); k++)
+ {
+ sem_usage_pair *usage = item->usages[k];
+ gcc_checking_assert (usage->item->index_in_class <
+ usage->item->cls->members.length ());
+ }
+ }
+ }
+ }
+#endif
+}
+
+/* Disposes split map traverse function. CLS_PTR is pointer to congruence
+ class, BSLOT is bitmap slot we want to release. DATA is mandatory,
+ but unused argument. */
+
+bool
+sem_item_optimizer::release_split_map (congruence_class * const &,
+ bitmap const &b, traverse_split_pair *)
+{
+ bitmap bmp = b;
+
+ BITMAP_FREE (bmp);
+
+ return true;
+}
+
+/* Process split operation for a class given as pointer CLS_PTR,
+ where bitmap B splits congruence class members. DATA is used
+ as argument of split pair. */
+
+bool
+sem_item_optimizer::traverse_congruence_split (congruence_class * const &cls,
+ bitmap const &b, traverse_split_pair *pair)
+{
+ sem_item_optimizer *optimizer = pair->optimizer;
+ const congruence_class *splitter_cls = pair->cls;
+
+ /* If counted bits are greater than zero and less than the number of members
+ a group will be splitted. */
+ unsigned popcount = bitmap_count_bits (b);
+
+ if (popcount > 0 && popcount < cls->members.length ())
+ {
+ congruence_class* newclasses[2] = { new congruence_class (class_id++), new congruence_class (class_id++) };
+
+ for (unsigned int i = 0; i < cls->members.length (); i++)
+ {
+ int target = bitmap_bit_p (b, i);
+ congruence_class *tc = newclasses[target];
+
+ add_item_to_class (tc, cls->members[i]);
+ }
+
+#ifdef ENABLE_CHECKING
+ for (unsigned int i = 0; i < 2; i++)
+ gcc_checking_assert (newclasses[i]->members.length ());
+#endif
+
+ if (splitter_cls == cls)
+ optimizer->splitter_class_removed = true;
+
+ /* Remove old class from worklist if presented. */
+ bool in_worklist = cls->in_worklist;
+
+ if (in_worklist)
+ cls->in_worklist = false;
+
+ congruence_class_group g;
+ g.hash = cls->members[0]->get_hash ();
+ g.type = cls->members[0]->type;
+
+ congruence_class_group *slot = optimizer->m_classes.find(&g);
+
+ for (unsigned int i = 0; i < slot->classes.length (); i++)
+ if (slot->classes[i] == cls)
+ {
+ slot->classes.ordered_remove (i);
+ break;
+ }
+
+ /* New class will be inserted and integrated to work list. */
+ for (unsigned int i = 0; i < 2; i++)
+ optimizer->add_class (newclasses[i]);
+
+ /* Two classes replace one, so that increment just by one. */
+ optimizer->m_classes_count++;
+
+ /* If OLD class was presented in the worklist, we remove the class
+ and replace it will both newly created classes. */
+ if (in_worklist)
+ for (unsigned int i = 0; i < 2; i++)
+ optimizer->worklist_push (newclasses[i]);
+ else /* Just smaller class is inserted. */
+ {
+ unsigned int smaller_index = newclasses[0]->members.length () <
+ newclasses[1]->members.length () ?
+ 0 : 1;
+ optimizer->worklist_push (newclasses[smaller_index]);
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, " congruence class splitted:\n");
+ cls->dump (dump_file, 4);
+
+ fprintf (dump_file, " newly created groups:\n");
+ for (unsigned int i = 0; i < 2; i++)
+ newclasses[i]->dump (dump_file, 4);
+ }
+
+ /* Release class if not presented in work list. */
+ if (!in_worklist)
+ delete cls;
+ }
+
+
+ return true;
+}
+
+/* Tests if a class CLS used as INDEXth splits any congruence classes.
+ Bitmap stack BMSTACK is used for bitmap allocation. */
+
+void
+sem_item_optimizer::do_congruence_step_for_index (congruence_class *cls,
+ unsigned int index)
+{
+ hash_map <congruence_class *, bitmap> split_map;
+
+ for (unsigned int i = 0; i < cls->members.length (); i++)
+ {
+ sem_item *item = cls->members[i];
+
+ /* Iterate all usages that have INDEX as usage of the item. */
+ for (unsigned int j = 0; j < item->usages.length (); j++)
+ {
+ sem_usage_pair *usage = item->usages[j];
+
+ if (usage->index != index)
+ continue;
+
+ bitmap *slot = split_map.get (usage->item->cls);
+ bitmap b;
+
+ if(!slot)
+ {
+ b = BITMAP_ALLOC (&m_bmstack);
+ split_map.put (usage->item->cls, b);
+ }
+ else
+ b = *slot;
+
+#if ENABLE_CHECKING
+ gcc_checking_assert (usage->item->cls);
+ gcc_checking_assert (usage->item->index_in_class <
+ usage->item->cls->members.length ());
+#endif
+
+ bitmap_set_bit (b, usage->item->index_in_class);
+ }
+ }
+
+ traverse_split_pair pair;
+ pair.optimizer = this;
+ pair.cls = cls;
+
+ splitter_class_removed = false;
+ split_map.traverse
+ <traverse_split_pair *, sem_item_optimizer::traverse_congruence_split> (&pair);
+
+ /* Bitmap clean-up. */
+ split_map.traverse
+ <traverse_split_pair *, sem_item_optimizer::release_split_map> (NULL);
+}
+
+/* Every usage of a congruence class CLS is a candidate that can split the
+ collection of classes. Bitmap stack BMSTACK is used for bitmap
+ allocation. */
+
+void
+sem_item_optimizer::do_congruence_step (congruence_class *cls)
+{
+ bitmap_iterator bi;
+ unsigned int i;
+
+ bitmap usage = BITMAP_ALLOC (&m_bmstack);
+
+ for (unsigned int i = 0; i < cls->members.length (); i++)
+ bitmap_ior_into (usage, cls->members[i]->usage_index_bitmap);
+
+ EXECUTE_IF_SET_IN_BITMAP (usage, 0, i, bi)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, " processing congruece step for class: %u, index: %u\n",
+ cls->id, i);
+
+ do_congruence_step_for_index (cls, i);
+
+ if (splitter_class_removed)
+ break;
+ }
+
+ BITMAP_FREE (usage);
+}
+
+/* Adds a newly created congruence class CLS to worklist. */
+
+void
+sem_item_optimizer::worklist_push (congruence_class *cls)
+{
+ /* Return if the class CLS is already presented in work list. */
+ if (cls->in_worklist)
+ return;
+
+ cls->in_worklist = true;
+ worklist.push_back (cls);
+}
+
+/* Pops a class from worklist. */
+
+congruence_class *
+sem_item_optimizer::worklist_pop (void)
+{
+ congruence_class *cls;
+
+ while (!worklist.empty ())
+ {
+ cls = worklist.front ();
+ worklist.pop_front ();
+ if (cls->in_worklist)
+ {
+ cls->in_worklist = false;
+
+ return cls;
+ }
+ else
+ {
+ /* Work list item was already intended to be removed.
+ The only reason for doing it is to split a class.
+ Thus, the class CLS is deleted. */
+ delete cls;
+ }
+ }
+
+ return NULL;
+}
+
+/* Iterative congruence reduction function. */
+
+void
+sem_item_optimizer::process_cong_reduction (void)
+{
+ for (hash_table<congruence_class_group_hash>::iterator it = m_classes.begin ();
+ it != m_classes.end (); ++it)
+ for (unsigned i = 0; i < (*it)->classes.length (); i++)
+ if ((*it)->classes[i]->is_class_used ())
+ worklist_push ((*it)->classes[i]);
+
+ if (dump_file)
+ fprintf (dump_file, "Worklist has been filled with: %lu\n",
+ worklist.size ());
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Congruence class reduction\n");
+
+ congruence_class *cls;
+ while ((cls = worklist_pop ()) != NULL)
+ do_congruence_step (cls);
+}
+
+/* Debug function prints all informations about congruence classes. */
+
+void
+sem_item_optimizer::dump_cong_classes (void)
+{
+ if (!dump_file)
+ return;
+
+ fprintf (dump_file,
+ "Congruence classes: %u (unique hash values: %lu), with total: %u items\n",
+ m_classes_count, m_classes.elements(), m_items.length ());
+
+ /* Histogram calculation. */
+ unsigned int max_index = 0;
+ unsigned int* histogram = XCNEWVEC (unsigned int, m_items.length () + 1);
+
+ for (hash_table<congruence_class_group_hash>::iterator it = m_classes.begin ();
+ it != m_classes.end (); ++it)
+
+ for (unsigned i = 0; i < (*it)->classes.length (); i++)
+ {
+ unsigned int c = (*it)->classes[i]->members.length ();
+ histogram[c]++;
+
+ if (c > max_index)
+ max_index = c;
+ }
+
+ fprintf (dump_file,
+ "Class size histogram [num of members]: number of classe number of classess\n");
+
+ for (unsigned int i = 0; i <= max_index; i++)
+ if (histogram[i])
+ fprintf (dump_file, "[%u]: %u classes\n", i, histogram[i]);
+
+ fprintf (dump_file, "\n\n");
+
+
+ if (dump_flags & TDF_DETAILS)
+ for (hash_table<congruence_class_group_hash>::iterator it = m_classes.begin ();
+ it != m_classes.end (); ++it)
+ {
+ fprintf (dump_file, " group: with %u classes:\n", (*it)->classes.length ());
+
+ for (unsigned i = 0; i < (*it)->classes.length (); i++)
+ {
+ (*it)->classes[i]->dump (dump_file, 4);
+
+ if(i < (*it)->classes.length () - 1)
+ fprintf (dump_file, " ");
+ }
+ }
+
+ free (histogram);
+}
+
+/* After reduction is done, we can declare all items in a group
+ to be equal. PREV_CLASS_COUNT is start number of classes
+ before reduction. */
+
+void
+sem_item_optimizer::merge_classes (unsigned int prev_class_count)
+{
+ unsigned int item_count = m_items.length ();
+ unsigned int class_count = m_classes_count;
+ unsigned int equal_items = item_count - class_count;
+
+ unsigned int non_singular_classes_count = 0;
+ unsigned int non_singular_classes_sum = 0;
+
+ for (hash_table<congruence_class_group_hash>::iterator it = m_classes.begin ();
+ it != m_classes.end (); ++it)
+ for (unsigned int i = 0; i < (*it)->classes.length (); i++)
+ {
+ congruence_class *c = (*it)->classes[i];
+ if (c->members.length () > 1)
+ {
+ non_singular_classes_count++;
+ non_singular_classes_sum += c->members.length ();
+ }
+ }
+
+ if (dump_file)
+ {
+ fprintf (dump_file, "\nItem count: %u\n", item_count);
+ fprintf (dump_file, "Congruent classes before: %u, after: %u\n",
+ prev_class_count, class_count);
+ fprintf (dump_file, "Average class size before: %.2f, after: %.2f\n",
+ 1.0f * item_count / prev_class_count,
+ 1.0f * item_count / class_count);
+ fprintf (dump_file, "Average non-singular class size: %.2f, count: %u\n",
+ 1.0f * non_singular_classes_sum / non_singular_classes_count,
+ non_singular_classes_count);
+ fprintf (dump_file, "Equal symbols: %u\n", equal_items);
+ fprintf (dump_file, "Fraction of visited symbols: %.2f%%\n\n",
+ 100.0f * equal_items / item_count);
+ }
+
+ for (hash_table<congruence_class_group_hash>::iterator it = m_classes.begin ();
+ it != m_classes.end (); ++it)
+ for (unsigned int i = 0; i < (*it)->classes.length (); i++)
+ {
+ congruence_class *c = (*it)->classes[i];
+
+ if (c->members.length () == 1)
+ continue;
+
+ gcc_assert (c->members.length ());
+
+ sem_item *source = c->members[0];
+
+ for (unsigned int j = 1; j < c->members.length (); j++)
+ {
+ sem_item *alias = c->members[j];
+ source->equals (alias, m_symtab_node_map);
+
+ if (dump_file)
+ {
+ fprintf (dump_file, "Semantic equality hit:%s->%s\n",
+ source->name (), alias->name ());
+ fprintf (dump_file, "Assembler symbol names:%s->%s\n",
+ source->asm_name (), alias->asm_name ());
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ source->dump_to_file (dump_file);
+ alias->dump_to_file (dump_file);
+ }
+
+ source->merge (alias);
+ }
+ }
+}
+
+/* Dump function prints all class members to a FILE with an INDENT. */
+
+void
+congruence_class::dump (FILE *file, unsigned int indent) const
+{
+ FPRINTF_SPACES (file, indent, "class with id: %u, hash: %u, items: %u\n",
+ id, members[0]->get_hash (), members.length ());
+
+ FPUTS_SPACES (file, indent + 2, "");
+ for (unsigned i = 0; i < members.length (); i++)
+ fprintf (file, "%s(%p/%u) ", members[i]->asm_name (), (void *) members[i]->decl,
+ members[i]->node->order);
+
+ fprintf (file, "\n");
+}
+
+/* Returns true if there's a member that is used from another group. */
+
+bool
+congruence_class::is_class_used (void)
+{
+ for (unsigned int i = 0; i < members.length (); i++)
+ if (members[i]->usages.length ())
+ return true;
+
+ return false;
+}
+
+/* Initialization and computation of symtab node hash, there data
+ are propagated later on. */
+
+static sem_item_optimizer *optimizer = NULL;
+
+/* Generate pass summary for IPA ICF pass. */
+
+static void
+ipa_icf_generate_summary (void)
+{
+ if (!optimizer)
+ optimizer = new sem_item_optimizer ();
+
+ optimizer->parse_funcs_and_vars ();
+}
+
+/* Write pass summary for IPA ICF pass. */
+
+static void
+ipa_icf_write_summary (void)
+{
+ gcc_assert (optimizer);
+
+ optimizer->write_summary ();
+}
+
+/* Read pass summary for IPA ICF pass. */
+
+static void
+ipa_icf_read_summary (void)
+{
+ if (!optimizer)
+ optimizer = new sem_item_optimizer ();
+
+ optimizer->read_summary ();
+ optimizer->register_hooks ();
+}
+
+/* Semantic equality exection function. */
+
+static unsigned int
+ipa_icf_driver (void)
+{
+ gcc_assert (optimizer);
+
+ optimizer->execute ();
+ optimizer->unregister_hooks ();
+
+ delete optimizer;
+
+ return 0;
+}
+
+const pass_data pass_data_ipa_icf =
+{
+ IPA_PASS, /* type */
+ "icf", /* name */
+ OPTGROUP_IPA, /* optinfo_flags */
+ TV_IPA_ICF, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ 0, /* todo_flags_finish */
+};
+
+class pass_ipa_icf : public ipa_opt_pass_d
+{
+public:
+ pass_ipa_icf (gcc::context *ctxt)
+ : ipa_opt_pass_d (pass_data_ipa_icf, ctxt,
+ ipa_icf_generate_summary, /* generate_summary */
+ ipa_icf_write_summary, /* write_summary */
+ ipa_icf_read_summary, /* read_summary */
+ NULL, /*
+ write_optimization_summary */
+ NULL, /*
+ read_optimization_summary */
+ NULL, /* stmt_fixup */
+ 0, /* function_transform_todo_flags_start */
+ NULL, /* function_transform */
+ NULL) /* variable_transform */
+ {}
+
+ /* opt_pass methods: */
+ virtual bool gate (function *)
+ {
+ return flag_ipa_icf_variables || flag_ipa_icf_functions;
+ }
+
+ virtual unsigned int execute (function *)
+ {
+ return ipa_icf_driver();
+ }
+}; // class pass_ipa_icf
+
+} // ipa_icf namespace
+
+ipa_opt_pass_d *
+make_pass_ipa_icf (gcc::context *ctxt)
+{
+ return new ipa_icf::pass_ipa_icf (ctxt);
+}
--- /dev/null
+/* Interprocedural semantic function equality pass
+ Copyright (C) 2014 Free Software Foundation, Inc.
+
+ Contributed by Jan Hubicka <hubicka@ucw.cz> and Martin Liska <mliska@suse.cz>
+
+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/>. */
+
+namespace ipa_icf {
+class sem_item;
+
+/* Congruence class encompasses a collection of either functions or
+ read-only variables. These items are considered to be equivalent
+ if not proved the oposite. */
+class congruence_class
+{
+public:
+ /* Congruence class constructor for a new class with _ID. */
+ congruence_class (unsigned int _id): in_worklist (false), id(_id)
+ {
+ }
+
+ /* Destructor. */
+ ~congruence_class ()
+ {
+ }
+
+ /* Dump function prints all class members to a FILE with an INDENT. */
+ void dump (FILE *file, unsigned int indent = 0) const;
+
+ /* Returns true if there's a member that is used from another group. */
+ bool is_class_used (void);
+
+ /* Flag is used in case we want to remove a class from worklist and
+ delete operation is quite expensive for
+ the data structure (linked list). */
+ bool in_worklist;
+
+ /* Vector of all group members. */
+ auto_vec <sem_item *> members;
+
+ /* Global unique class identifier. */
+ unsigned int id;
+};
+
+/* Semantic item type enum. */
+enum sem_item_type
+{
+ FUNC,
+ VAR
+};
+
+/* Semantic item usage pair. */
+class sem_usage_pair
+{
+public:
+ /* Constructor for key value pair, where _ITEM is key and _INDEX is a target. */
+ sem_usage_pair (sem_item *_item, unsigned int _index);
+
+ /* Target semantic item where an item is used. */
+ sem_item *item;
+
+ /* Index of usage of such an item. */
+ unsigned int index;
+};
+
+/* Semantic item is a base class that encapsulates all shared functionality
+ for both semantic function and variable items. */
+class sem_item
+{
+public:
+ /* Semantic item constructor for a node of _TYPE, where STACK is used
+ for bitmap memory allocation. */
+ sem_item (sem_item_type _type, bitmap_obstack *stack);
+
+ /* Semantic item constructor for a node of _TYPE, where STACK is used
+ for bitmap memory allocation. The item is based on symtab node _NODE
+ with computed _HASH. */
+ sem_item (sem_item_type _type, symtab_node *_node, hashval_t _hash,
+ bitmap_obstack *stack);
+
+ virtual ~sem_item ();
+
+ /* Dump function for debugging purpose. */
+ DEBUG_FUNCTION void dump (void);
+
+ /* Initialize semantic item by info reachable during LTO WPA phase. */
+ virtual void init_wpa (void) = 0;
+
+ /* Semantic item initialization function. */
+ virtual void init (void) = 0;
+
+ /* Add reference to a semantic TARGET. */
+ void add_reference (sem_item *target);
+
+ /* Gets symbol name of the item. */
+ const char *name (void)
+ {
+ return node->name ();
+ }
+
+ /* Gets assembler name of the item. */
+ const char *asm_name (void)
+ {
+ return node->asm_name ();
+ }
+
+ /* Fast equality function based on knowledge known in WPA. */
+ virtual bool equals_wpa (sem_item *item,
+ hash_map <symtab_node *, sem_item *> &ignored_nodes) = 0;
+
+ /* Returns true if the item equals to ITEM given as arguemnt. */
+ virtual bool equals (sem_item *item,
+ hash_map <symtab_node *, sem_item *> &ignored_nodes) = 0;
+
+ /* References independent hash function. */
+ virtual hashval_t get_hash (void) = 0;
+
+ /* Merges instance with an ALIAS_ITEM, where alias, thunk or redirection can
+ be applied. */
+ virtual bool merge (sem_item *alias_item) = 0;
+
+ /* Dump symbol to FILE. */
+ virtual void dump_to_file (FILE *file) = 0;
+
+ /* Return base tree that can be used for compatible_types_p and
+ contains_polymorphic_type_p comparison. */
+
+ static bool get_base_types (tree *t1, tree *t2);
+
+ /* Item type. */
+ sem_item_type type;
+
+ /* Symtab node. */
+ symtab_node *node;
+
+ /* Declaration tree node. */
+ tree decl;
+
+ /* Semantic references used that generate congruence groups. */
+ vec <sem_item *> refs;
+
+ /* Pointer to a congruence class the item belongs to. */
+ congruence_class *cls;
+
+ /* Index of the item in a class belonging to. */
+ unsigned int index_in_class;
+
+ /* List of semantic items where the instance is used. */
+ vec <sem_usage_pair *> usages;
+
+ /* A bitmap with indices of all classes referencing this item. */
+ bitmap usage_index_bitmap;
+
+ /* List of tree references (either FUNC_DECL or VAR_DECL). */
+ vec <tree> tree_refs;
+
+ /* A set with symbol table references. */
+ hash_set <symtab_node *> refs_set;
+
+protected:
+ /* Cached, once calculated hash for the item. */
+ hashval_t hash;
+
+private:
+ /* Initialize internal data structures. Bitmap STACK is used for
+ bitmap memory allocation process. */
+ void setup (bitmap_obstack *stack);
+}; // class sem_item
+
+class sem_function: public sem_item
+{
+public:
+ /* Semantic function constructor that uses STACK as bitmap memory stack. */
+ sem_function (bitmap_obstack *stack);
+
+ /* Constructor based on callgraph node _NODE with computed hash _HASH.
+ Bitmap STACK is used for memory allocation. */
+ sem_function (cgraph_node *_node, hashval_t _hash, bitmap_obstack *stack);
+
+ ~sem_function ();
+
+ inline virtual void init_wpa (void)
+ {
+ parse_tree_args ();
+ }
+
+ virtual void init (void);
+ virtual bool equals_wpa (sem_item *item,
+ hash_map <symtab_node *, sem_item *> &ignored_nodes);
+ virtual hashval_t get_hash (void);
+ virtual bool equals (sem_item *item,
+ hash_map <symtab_node *, sem_item *> &ignored_nodes);
+ virtual bool merge (sem_item *alias_item);
+
+ /* Dump symbol to FILE. */
+ virtual void dump_to_file (FILE *file)
+ {
+ gcc_assert (file);
+ dump_function_to_file (decl, file, TDF_DETAILS);
+ }
+
+ /* Parses function arguments and result type. */
+ void parse_tree_args (void);
+
+ /* Returns cgraph_node. */
+ inline cgraph_node *get_node (void)
+ {
+ return dyn_cast <cgraph_node *> (node);
+ }
+
+ /* Improve accumulated hash for HSTATE based on a gimple statement STMT. */
+ void hash_stmt (inchash::hash *inchash, gimple stmt);
+
+ /* Return true if polymorphic comparison must be processed. */
+ bool compare_polymorphic_p (void);
+
+ /* For a given call graph NODE, the function constructs new
+ semantic function item. */
+ static sem_function *parse (cgraph_node *node, bitmap_obstack *stack);
+
+ /* Exception handling region tree. */
+ eh_region region_tree;
+
+ /* Result type tree node. */
+ tree result_type;
+
+ /* Array of argument tree types. */
+ vec <tree> arg_types;
+
+ /* Number of function arguments. */
+ unsigned int arg_count;
+
+ /* Total amount of edges in the function. */
+ unsigned int edge_count;
+
+ /* Vector of sizes of all basic blocks. */
+ vec <unsigned int> bb_sizes;
+
+ /* Control flow graph checksum. */
+ hashval_t cfg_checksum;
+
+ /* GIMPLE codes hash value. */
+ hashval_t gcode_hash;
+
+ /* Total number of SSA names used in the function. */
+ unsigned ssa_names_size;
+
+ /* Array of structures for all basic blocks. */
+ vec <ipa_icf_gimple::sem_bb *> bb_sorted;
+
+private:
+ /* Calculates hash value based on a BASIC_BLOCK. */
+ hashval_t get_bb_hash (const ipa_icf_gimple::sem_bb *basic_block);
+
+ /* For given basic blocks BB1 and BB2 (from functions FUNC1 and FUNC),
+ true value is returned if phi nodes are semantically
+ equivalent in these blocks . */
+ bool compare_phi_node (basic_block bb1, basic_block bb2);
+
+ /* Basic blocks dictionary BB_DICT returns true if SOURCE index BB
+ corresponds to TARGET. */
+ bool bb_dict_test (int* bb_dict, int source, int target);
+
+ /* Iterates all tree types in T1 and T2 and returns true if all types
+ are compatible. If COMPARE_POLYMORPHIC is set to true,
+ more strict comparison is executed. */
+ bool compare_type_list (tree t1, tree t2, bool compare_polymorphic);
+
+ /* If cgraph edges E1 and E2 are indirect calls, verify that
+ ICF flags are the same. */
+ bool compare_edge_flags (cgraph_edge *e1, cgraph_edge *e2);
+
+ /* For a given symbol table nodes N1 and N2, we check that FUNCTION_DECLs
+ point to a same function. Comparison can be skipped if IGNORED_NODES
+ contains these nodes. */
+ bool compare_cgraph_references (hash_map <symtab_node *, sem_item *>
+ &ignored_nodes,
+ symtab_node *n1, symtab_node *n2);
+
+ /* Processes function equality comparison. */
+ bool equals_private (sem_item *item,
+ hash_map <symtab_node *, sem_item *> &ignored_nodes);
+
+ /* Returns true if tree T can be compared as a handled component. */
+ static bool icf_handled_component_p (tree t);
+
+ /* Function checker stores binding between functions. */
+ ipa_icf_gimple::func_checker *m_checker;
+
+ /* COMPARED_FUNC is a function that we compare to. */
+ sem_function *m_compared_func;
+}; // class sem_function
+
+class sem_variable: public sem_item
+{
+public:
+ /* Semantic variable constructor that uses STACK as bitmap memory stack. */
+ sem_variable (bitmap_obstack *stack);
+
+ /* Constructor based on callgraph node _NODE with computed hash _HASH.
+ Bitmap STACK is used for memory allocation. */
+
+ sem_variable (varpool_node *_node, hashval_t _hash, bitmap_obstack *stack);
+
+ inline virtual void init_wpa (void) {}
+
+ /* Semantic variable initialization function. */
+ inline virtual void init (void)
+ {
+ decl = get_node ()->decl;
+ ctor = ctor_for_folding (decl);
+ }
+
+ virtual hashval_t get_hash (void);
+ virtual bool merge (sem_item *alias_item);
+ virtual void dump_to_file (FILE *file);
+ virtual bool equals (sem_item *item,
+ hash_map <symtab_node *, sem_item *> &ignored_nodes);
+
+ /* Fast equality variable based on knowledge known in WPA. */
+ inline virtual bool equals_wpa (sem_item *item,
+ hash_map <symtab_node *, sem_item *> & ARG_UNUSED(ignored_nodes))
+ {
+ gcc_assert (item->type == VAR);
+ return true;
+ }
+
+ /* Returns varpool_node. */
+ inline varpool_node *get_node (void)
+ {
+ return dyn_cast <varpool_node *> (node);
+ }
+
+ /* Parser function that visits a varpool NODE. */
+ static sem_variable *parse (varpool_node *node, bitmap_obstack *stack);
+
+ /* Variable constructor. */
+ tree ctor;
+
+private:
+ /* Iterates though a constructor and identifies tree references
+ we are interested in semantic function equality. */
+ void parse_tree_refs (tree t);
+
+ /* Compares trees T1 and T2 for semantic equality. */
+ static bool equals (tree t1, tree t2);
+
+ /* Compare that symbol sections are either NULL or have same name. */
+ bool compare_sections (sem_variable *alias);
+
+}; // class sem_variable
+
+class sem_item_optimizer;
+
+struct congruence_class_group
+{
+ hashval_t hash;
+ sem_item_type type;
+ vec <congruence_class *> classes;
+};
+
+/* Congruence class set structure. */
+struct congruence_class_group_hash: typed_noop_remove <congruence_class_group>
+{
+ typedef congruence_class_group value_type;
+ typedef congruence_class_group compare_type;
+
+ static inline hashval_t hash (const value_type *item)
+ {
+ return item->hash;
+ }
+
+ static inline int equal (const value_type *item1, const compare_type *item2)
+ {
+ return item1->hash == item2->hash && item1->type == item2->type;
+ }
+};
+
+struct traverse_split_pair
+{
+ sem_item_optimizer *optimizer;
+ class congruence_class *cls;
+};
+
+/* Semantic item optimizer includes all top-level logic
+ related to semantic equality comparison. */
+class sem_item_optimizer
+{
+public:
+ sem_item_optimizer ();
+ ~sem_item_optimizer ();
+
+ /* Function responsible for visiting all potential functions and
+ read-only variables that can be merged. */
+ void parse_funcs_and_vars (void);
+
+ /* Optimizer entry point. */
+ void execute (void);
+
+ /* Dump function. */
+ void dump (void);
+
+ /* Verify congruence classes if checking is enabled. */
+ void verify_classes (void);
+
+ /* Write IPA ICF summary for symbols. */
+ void write_summary (void);
+
+ /* Read IPA IPA ICF summary for symbols. */
+ void read_summary (void);
+
+ /* Callgraph removal hook called for a NODE with a custom DATA. */
+ static void cgraph_removal_hook (cgraph_node *node, void *data);
+
+ /* Varpool removal hook called for a NODE with a custom DATA. */
+ static void varpool_removal_hook (varpool_node *node, void *data);
+
+ /* Worklist of congruence classes that can potentially
+ refine classes of congruence. */
+ std::list<congruence_class *> worklist;
+
+ /* Remove semantic ITEM and release memory. */
+ void remove_item (sem_item *item);
+
+ /* Remove symtab NODE triggered by symtab removal hooks. */
+ void remove_symtab_node (symtab_node *node);
+
+ /* Register callgraph and varpool hooks. */
+ void register_hooks (void);
+
+ /* Unregister callgraph and varpool hooks. */
+ void unregister_hooks (void);
+
+ /* Adds a CLS to hashtable associated by hash value. */
+ void add_class (congruence_class *cls);
+
+ /* Gets a congruence class group based on given HASH value and TYPE. */
+ congruence_class_group *get_group_by_hash (hashval_t hash,
+ sem_item_type type);
+
+private:
+
+ /* Congruence classes are built by hash value. */
+ void build_hash_based_classes (void);
+
+ /* Semantic items in classes having more than one element and initialized.
+ In case of WPA, we load function body. */
+ void parse_nonsingleton_classes (void);
+
+ /* Equality function for semantic items is used to subdivide existing
+ classes. If IN_WPA, fast equality function is invoked. */
+ void subdivide_classes_by_equality (bool in_wpa = false);
+
+ /* Debug function prints all informations about congruence classes. */
+ void dump_cong_classes (void);
+
+ /* Build references according to call graph. */
+ void build_graph (void);
+
+ /* Iterative congruence reduction function. */
+ void process_cong_reduction (void);
+
+ /* After reduction is done, we can declare all items in a group
+ to be equal. PREV_CLASS_COUNT is start number of classes
+ before reduction. */
+ void merge_classes (unsigned int prev_class_count);
+
+ /* Adds a newly created congruence class CLS to worklist. */
+ void worklist_push (congruence_class *cls);
+
+ /* Pops a class from worklist. */
+ congruence_class *worklist_pop ();
+
+ /* Every usage of a congruence class CLS is a candidate that can split the
+ collection of classes. Bitmap stack BMSTACK is used for bitmap
+ allocation. */
+ void do_congruence_step (congruence_class *cls);
+
+ /* Tests if a class CLS used as INDEXth splits any congruence classes.
+ Bitmap stack BMSTACK is used for bitmap allocation. */
+ void do_congruence_step_for_index (congruence_class *cls, unsigned int index);
+
+ /* Makes pairing between a congruence class CLS and semantic ITEM. */
+ static void add_item_to_class (congruence_class *cls, sem_item *item);
+
+ /* Disposes split map traverse function. CLS is congruence
+ class, BSLOT is bitmap slot we want to release. DATA is mandatory,
+ but unused argument. */
+ static bool release_split_map (congruence_class * const &cls, bitmap const &b,
+ traverse_split_pair *pair);
+
+ /* Process split operation for a cognruence class CLS,
+ where bitmap B splits congruence class members. DATA is used
+ as argument of split pair. */
+ static bool traverse_congruence_split (congruence_class * const &cls,
+ bitmap const &b,
+ traverse_split_pair *pair);
+
+ /* Reads a section from LTO stream file FILE_DATA. Input block for DATA
+ contains LEN bytes. */
+ void read_section (lto_file_decl_data *file_data, const char *data,
+ size_t len);
+
+ /* Removes all callgraph and varpool nodes that are marked by symtab
+ as deleted. */
+ void filter_removed_items (void);
+
+ /* Vector of semantic items. */
+ vec <sem_item *> m_items;
+
+ /* A set containing all items removed by hooks. */
+ hash_set <symtab_node *> m_removed_items_set;
+
+ /* Hashtable of congruence classes */
+ hash_table <congruence_class_group_hash> m_classes;
+
+ /* Count of congruence classes. */
+ unsigned int m_classes_count;
+
+ /* Map data structure maps symtab nodes to semantic items. */
+ hash_map <symtab_node *, sem_item *> m_symtab_node_map;
+
+ /* Set to true if a splitter class is removed. */
+ bool splitter_class_removed;
+
+ /* Global unique class id counter. */
+ static unsigned int class_id;
+
+ /* Callgraph node removal hook holder. */
+ cgraph_node_hook_list *m_cgraph_node_hooks;
+
+ /* Varpool node removal hook holder. */
+ varpool_node_hook_list *m_varpool_node_hooks;
+
+ /* Bitmap stack. */
+ bitmap_obstack m_bmstack;
+}; // class sem_item_optimizer
+
+} // ipa_icf namespace
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