Hello,
this is an update on the LTO pass we've been working on. The optimization is
called ipa-initcall-cp because it propagates constant values written to
variables with static lifetimes (such as ones initialized in initialization
functions).
This patch can be applied to:
commit 3cce71b23f6ed221b4335b600e718d79903cc83d
Date: Wed Dec 4 20:04:10 2019 +0000
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@278975
138bc75d-0d04-0410-961f-82ee72b054a4
This patch can now successfully compile all benchmarks on the SPEC CPU2017
benchmarking suite. ~12 of the benchmarks have variables that can be
eliminated with this transformation. I am pasting the patch at the
bottom of the e-mail. I'll be working on adding some of the test cases onto
gcc's testing suite.
In my previous e-mail I asked some questions. Some of them still remain,
others I have answered:
> Question #1: Can someone please tell me what would be the best kind of clones
> to use in this use case?
I think that the only API which makes sense here is
create_version_clone_with_body because we want to modify the body of the
clones.
> Question #2: I found out that clones produced with
> create_clone_version_with_body are not themselves versionable. What is the
> reason behind this?
Still not sure why this is the case.
> Question #3: I have added a flag to cgraph_nodes to skip ipa-cp. This flag is
> true for the original functions which have been removed from the call graph.
> If this flag is removed, then cgraph_nodes removed from the call graph will
> trigger an assertion in ipa-cp (ipa-cp.c:1195). I would like to not have to
> add this flag to cgraph_node but I am not sure what to do.
Still not sure how to remove this graph. Ideally, ipa-cp would not
trigger that assertion because it shouldn't try to propagate constants
on cgraph_nodes that are not connected to the graph any more.
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 6b857bd..fb4ba09 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -1370,6 +1370,7 @@ OBJS = \
internal-fn.o \
ipa-cp.o \
ipa-sra.o \
+ ipa-initcall-cp.o \
ipa-devirt.o \
ipa-fnsummary.o \
ipa-polymorphic-call.o \
diff --git a/gcc/cgraph.c b/gcc/cgraph.c
index 7288440..0d56149 100644
--- a/gcc/cgraph.c
+++ b/gcc/cgraph.c
@@ -288,6 +288,7 @@ symbol_table::create_empty (void)
node->type = SYMTAB_FUNCTION;
node->frequency = NODE_FREQUENCY_NORMAL;
node->count_materialization_scale = REG_BR_PROB_BASE;
+ node->skip_ipa_cp = false;
cgraph_count++;
return node;
@@ -3548,6 +3549,7 @@ cgraph_node::get_untransformed_body (void)
name = lto_get_decl_name_mapping (file_data, name);
struct lto_in_decl_state *decl_state
= lto_get_function_in_decl_state (file_data, decl);
+ gcc_assert (decl_state != NULL);
cgraph_node *origin = this;
while (origin->clone_of)
diff --git a/gcc/cgraph.h b/gcc/cgraph.h
index 9c086fe..806ed56 100644
--- a/gcc/cgraph.h
+++ b/gcc/cgraph.h
@@ -901,6 +901,8 @@ struct GTY((tag ("SYMTAB_FUNCTION"))) cgraph_node : public
symtab_node
{
friend class symbol_table;
+ bool skip_ipa_cp;
+
/* Remove the node from cgraph and all inline clones inlined into it.
Skip however removal of FORBIDDEN_NODE and return true if it needs to be
removed. This allows to call the function from outer loop walking clone
diff --git a/gcc/common.opt b/gcc/common.opt
index 404b6aa..00c86dc 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -3344,4 +3344,10 @@ fipa-ra
Common Report Var(flag_ipa_ra) Optimization
Use caller save register across calls if possible.
+finitcall-cp
+Common Report Var(flag_initcall_cp) TBD.
+
+finitcall-cp-dryrun
+Common Report Var(flag_initcall_cp_dryrun) TBD.
+
; This comment is to ensure we retain the blank line above.
diff --git a/gcc/ipa-cp.c b/gcc/ipa-cp.c
index 693c7a2..4169dfb 100644
--- a/gcc/ipa-cp.c
+++ b/gcc/ipa-cp.c
@@ -1187,7 +1187,7 @@ initialize_node_lattices (struct cgraph_node *node)
gcc_checking_assert (node->has_gimple_body_p ());
- if (!ipa_get_param_count (info))
+ if (!ipa_get_param_count (info) || node->skip_ipa_cp)
disable = true;
else if (node->local)
{
diff --git a/gcc/ipa-initcall-cp.c b/gcc/ipa-initcall-cp.c
new file mode 100644
index 0000000..264bf38
--- /dev/null
+++ b/gcc/ipa-initcall-cp.c
@@ -0,0 +1,1467 @@
+/* Initcall constant propagation pass. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "backend.h"
+#include "tree.h"
+#include "tree-eh.h"
+#include "gimple.h"
+#include "gimple-expr.h"
+#include "gimple-iterator.h"
+#include "predict.h"
+#include "alloc-pool.h"
+#include "tree-pass.h"
+#include "cgraph.h"
+#include "diagnostic.h"
+#include "fold-const.h"
+#include "gimple-fold.h"
+#include "symbol-summary.h"
+#include "tree-vrp.h"
+#include "ipa-prop.h"
+#include "tree-pretty-print.h"
+#include "tree-inline.h"
+#include "ipa-fnsummary.h"
+#include "ipa-utils.h"
+#include "tree-ssa-ccp.h"
+#include "stringpool.h"
+#include "attribs.h"
+#include "gimple-pretty-print.h"
+#include "ssa.h"
+
+bool
+reach_nodes_via_bb1 (cgraph_node *n2);
+static bool
+bb1_dominates_bb2 (basic_block, basic_block, cgraph_node *);
+static bool
+write_before_call (struct ipa_ref *, struct ipa_ref *);
+static bool
+call_before_read (struct ipa_ref *, struct ipa_ref *);
+static hash_map<const char *, unsigned> *clone_num_suffixes1;
+static hash_map<cgraph_node *, cgraph_node *> *func_to_clone;
+static vec<struct cgraph_node *>
+get_nondominated_callees (cgraph_node *caller, cgraph_node *callee,
+ bool *exitEarly = NULL);
+
+static bool
+comdat_can_be_unshared_p_1 (symtab_node *node)
+{
+ if (!node->externally_visible)
+ return true;
+ if (node->address_can_be_compared_p ())
+ {
+ struct ipa_ref *ref;
+
+ for (unsigned int i = 0; node->iterate_referring (i, ref); i++)
+ if (ref->address_matters_p ())
+ return false;
+ }
+
+ /* If the symbol is used in some weird way,
+ * better to not touch it. */
+ if (node->force_output)
+ return false;
+
+ /* Explicit instantiations needs to be output when possibly
+ used externally. */
+ if (node->forced_by_abi && TREE_PUBLIC (node->decl)
+ && (node->resolution != LDPR_PREVAILING_DEF_IRONLY
+ && !flag_whole_program))
+ return false;
+
+ /* Non-readonly and volatile variables cannot be duplicated. */
+ if (is_a<varpool_node *> (node)
+ && (!TREE_READONLY (node->decl) || TREE_THIS_VOLATILE (node->decl)))
+ return false;
+ return true;
+}
+
+/* COMDAT functions must be shared only if they have address taken,
+ otherwise we can produce our own private implementation with
+ -fwhole-program.
+ Return true when turning COMDAT function static cannot lead to wrong
+ code when the resulting object links with a library defining same
+ COMDAT.
+
+ Virtual functions do have their addresses taken from the vtables,
+ but in C++ there is no way to compare their addresses
+ for equality. */
+
+static bool
+comdat_can_be_unshared_p (symtab_node *node)
+{
+ if (!comdat_can_be_unshared_p_1 (node))
+ return false;
+ if (node->same_comdat_group)
+ {
+ symtab_node *next;
+
+ /* If more than one function is in the same COMDAT group, it must
+ be shared even if just one function in the comdat group has
+ address taken. */
+ for (next = node->same_comdat_group; next != node;
+ next = next->same_comdat_group)
+ if (!comdat_can_be_unshared_p_1 (next))
+ return false;
+ }
+ return true;
+}
+
+/* Return true when function NODE should
+ * be considered externally visible. */
+
+static bool
+cgraph_externally_visible_p (struct cgraph_node *node, bool whole_program)
+{
+ while (node->transparent_alias && node->definition)
+ node = node->get_alias_target ();
+ if (!node->definition)
+ return false;
+ if (!TREE_PUBLIC (node->decl) || DECL_EXTERNAL (node->decl))
+ return false;
+
+ /* Do not try to localize built-in functions yet.
+ One of problems is that we
+ end up mangling their asm for
+ WHOPR that makes it impossible to call them
+ using the implicit built-in declarations
+ anymore. Similarly this enables
+ us to remove them as unreachable before
+ actual calls may appear during
+ expansion or folding. */
+ if (fndecl_built_in_p (node->decl))
+ return true;
+
+ /* If linker counts on us, we must preserve the function. */
+ if (node->used_from_object_file_p ())
+ return true;
+ if (DECL_PRESERVE_P (node->decl))
+ return true;
+ if (lookup_attribute ("externally_visible", DECL_ATTRIBUTES (node->decl)))
+ return true;
+ if (lookup_attribute ("noipa", DECL_ATTRIBUTES (node->decl)))
+ return true;
+ if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
+ && lookup_attribute ("dllexport", DECL_ATTRIBUTES (node->decl)))
+ return true;
+ if (node->resolution == LDPR_PREVAILING_DEF_IRONLY)
+ return false;
+ /* When doing LTO or whole program, we can bring COMDAT functions
+ static.
+ This improves code quality and we know we will duplicate them at
+ most twice
+ (in the case that we are not using plugin and link with object
+ file implementing same COMDAT) */
+ if (((in_lto_p || whole_program) && !flag_incremental_link)
+ && DECL_COMDAT (node->decl) && comdat_can_be_unshared_p (node))
+ return false;
+
+ /* When doing link time optimizations,
+ * hidden symbols become local. */
+ if ((in_lto_p && !flag_incremental_link)
+ && (DECL_VISIBILITY (node->decl) == VISIBILITY_HIDDEN
+ || DECL_VISIBILITY (node->decl) == VISIBILITY_INTERNAL)
+ /* Be sure that node is defined in IR file, not in other object
+ file. In that case we don't set
+ used_from_other_object_file. */
+ && node->definition)
+ ;
+ else if (!whole_program)
+ return true;
+
+ if (MAIN_NAME_P (DECL_NAME (node->decl)))
+ return true;
+
+ return false;
+}
+
+typedef vec<struct ipa_ref *> ipa_ref_vec;
+
+// XXX: Move to ipa-ref.h
+static const char *
+stringify_ipa_ref_use (ipa_ref_use use)
+{
+ switch (use)
+ {
+ case IPA_REF_LOAD:
+ return "IPA_REF_LOAD";
+ break;
+ case IPA_REF_STORE:
+ return "IPA_REF_STORE";
+ break;
+ case IPA_REF_ADDR:
+ return "IPA_REF_ADDR";
+ break;
+ case IPA_REF_ALIAS:
+ return "IPA_REF_ALIAS";
+ break;
+ default:
+ return "<unknown>";
+ }
+}
+
+static void
+load_function_body_of_ipa_ref (cgraph_node *node)
+{
+ if (in_lto_p)
+ {
+ cgraph_node *f_cnode2 = node->ultimate_alias_target ();
+ if (dump_file)
+ {
+ fprintf (dump_file, "%s: for function '%s'\n", __func__,
+ f_cnode2->dump_asm_name ());
+ dump_node (f_cnode2->decl, TDF_DETAILS, dump_file);
+ }
+ f_cnode2->get_untransformed_body ();
+ }
+}
+
+static void
+load_function_body_of_ipa_ref (struct ipa_ref *ref)
+{
+ /* IPA passes don't get the function bodies during LTO. */
+ if (in_lto_p)
+ {
+ symtab_node *f_node = ref->referring;
+ cgraph_node *f_cnode = dyn_cast<cgraph_node *> (f_node);
+ load_function_body_of_ipa_ref (f_cnode);
+ }
+}
+
+static void
+dump_vnode_ipa_ref (ipa_ref *ref)
+{
+ fprintf (dump_file, "Reference type: %s\n", stringify_ipa_ref_use
(ref->use));
+
+ symtab_node *f_node = ref->referring;
+ fprintf (dump_file, "Reference function: %s\n", f_node->dump_asm_name ());
+
+ fprintf (dump_file, "Gimple stmt (@0x%lx, lto_stmt_uid: %u):\n",
+ (long) ref->stmt, ref->lto_stmt_uid);
+ load_function_body_of_ipa_ref (ref);
+ print_gimple_stmt (dump_file, ref->stmt, 0, TDF_NONE);
+}
+
+// XXX: Move to tree.h
+static bool
+tree_code_is_cst (tree op)
+{
+ // XXX: use cprop_constant_p () here?
+ int code = TREE_CODE (op);
+ if (code == INTEGER_CST || code == REAL_CST || code == COMPLEX_CST
+ || code == VECTOR_CST)
+ return true;
+ return false;
+}
+
+/* Return true of all ops of assignment are constants. */
+static bool
+gimple_assign_is_single_const (gimple *stmt)
+{
+ tree op;
+
+ gcc_assert (gimple_code (stmt) == GIMPLE_ASSIGN);
+
+ if (gimple_has_volatile_ops (stmt))
+ {
+ if (dump_file)
+ fprintf (dump_file, "has volatile ops!\n");
+ return false;
+ }
+
+ if (gimple_num_ops (stmt) != 2)
+ {
+ if (dump_file)
+ fprintf (dump_file, "wrong num of ops: %u!\n", gimple_num_ops (stmt));
+ return false;
+ }
+
+ op = gimple_op (stmt, 1);
+ if (!tree_code_is_cst (op))
+ {
+ if (dump_file)
+ fprintf (dump_file, "op is not cst!\n");
+ return false;
+ }
+
+ return true;
+}
+
+// XXX: Move to ipa-utils.c
+// XXX: from/to could be const
+static bool
+path_exists_dfs (hash_set<cgraph_node *> *visited, cgraph_node *current,
+ cgraph_node *target)
+{
+ if (current == target)
+ return true;
+
+ visited->add (current);
+
+ cgraph_edge *cs;
+ for (cs = current->callees; cs; cs = cs->next_callee)
+ {
+ cgraph_node *callee = cs->callee->function_symbol ();
+ if (!visited->contains (callee))
+ {
+ if (path_exists_dfs (visited, callee, target))
+ {
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
+// XXX: Move to ipa-utils.c
+// XXX: from/to could be const
+static bool
+path_exists (cgraph_node *from, cgraph_node *to)
+{
+ hash_set<cgraph_node *> visited;
+ bool found_path = path_exists_dfs (&visited, from, to);
+ visited.empty ();
+
+ if (dump_file)
+ {
+ fprintf (dump_file, "Found ");
+ if (!found_path)
+ fprintf (dump_file, "*no* ");
+ fprintf (dump_file, "path from %s to %s.\n", from->name (), to->name ());
+ }
+ return found_path;
+}
+
+static vec<struct cgraph_node *>
+get_nondominated_callees (cgraph_node *caller, cgraph_node *callee,
+ bool *exitEarly)
+{
+ // assumptions:
+ // * there is a callsite from caller to callee
+
+ if (in_lto_p)
+ caller->get_untransformed_body ();
+
+ function *func = DECL_STRUCT_FUNCTION (caller->decl);
+ basic_block bb;
+ bool found = false;
+ FOR_EACH_BB_FN (bb, func)
+ {
+ 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_CALL)
+ continue;
+
+ // The question here is, what happens if we don't have
+ // a tree that is of the type
+ // var = call()
+ // and instead we have a tree of the type
+ // call()
+ // are these trees even possible?
+ // I would prefer if they are all the same...
+ if (dump_file)
+ print_gimple_stmt (dump_file, stmt, 0, TDF_NONE);
+ tree rhs = gimple_op (stmt, 1);
+ if (TREE_CODE (rhs) == RECORD_TYPE)
+ {
+ gcc_assert (exitEarly);
+ *exitEarly = true;
+ return vNULL;
+ }
+ tree callee_decl = gimple_call_fndecl (stmt);
+ if (!callee_decl)
+ {
+ gcc_assert (exitEarly);
+ *exitEarly = true;
+ return vNULL;
+ }
+ cgraph_node *callee_node = cgraph_node::get (callee_decl);
+ if (callee_node != callee)
+ continue;
+
+ found = true;
+ }
+ if (found)
+ break;
+ }
+
+ gcc_assert (found);
+
+ // At this point in the program, we hold a valid bb.
+ // The callee is located
+ vec<struct cgraph_node *> callees = vNULL;
+ basic_block bb_c;
+ FOR_EACH_BB_FN (bb_c, func)
+ {
+ bool self_dominates = bb == bb_c;
+ bool bb_dominates_bbc = bb1_dominates_bb2 (bb, bb_c, caller);
+ if (bb_dominates_bbc && !self_dominates)
+ continue;
+
+ for (gimple_stmt_iterator gsi = gsi_start_bb (bb_c); !gsi_end_p (gsi);
+ gsi_next (&gsi))
+ {
+ gimple *stmt = gsi_stmt (gsi);
+ if (gimple_code (stmt) != GIMPLE_CALL)
+ continue;
+
+ tree callee_decl = gimple_call_fndecl (stmt);
+ cgraph_node *callee_node = cgraph_node::get (callee_decl);
+
+ if (fndecl_built_in_p (callee_node->decl))
+ continue;
+
+ if (self_dominates && callee_node == callee)
+ {
+ break;
+ }
+
+ callees.safe_push (callee_node);
+ }
+ }
+ return callees;
+}
+
+// XXX: Move to class symtab_node in cgraph.h
+static ipa_ref *
+symtab_node_iterate_address_uses (symtab_node *n, unsigned i, ipa_ref *&ref)
+{
+ ipa_ref *retval = NULL;
+ for (int i = 0; n->iterate_referring (i, retval); i++)
+ if (ref->use == IPA_REF_ADDR)
+ return ref;
+ return NULL;
+}
+
+// XXX: Move to class symtab_node in cgraph.h
+static bool
+symtab_node_address_matters_p (symtab_node *n)
+{
+ struct ipa_ref *ref;
+
+ if (!n->address_can_be_compared_p ())
+ return false;
+ if (n->externally_visible || n->force_output)
+ return true;
+
+ for (unsigned int i = 0; n->iterate_referring (i, ref); i++)
+ if (ref->address_matters_p ())
+ return true;
+ return false;
+}
+
+static bool
+bb1_dominates_bb2 (basic_block bb1, basic_block bb2, cgraph_node *cnode)
+{
+ // self dominance
+ if (bb1 == bb2)
+ return true;
+
+ push_cfun (DECL_STRUCT_FUNCTION (cnode->decl));
+
+ /* If dominator info is not available, we need to calculate it. */
+ if (!dom_info_available_p (CDI_DOMINATORS))
+ calculate_dominance_info (CDI_DOMINATORS);
+
+ /* Check if the read is dominated by the write. */
+ bool ret = dominated_by_p (CDI_DOMINATORS, bb2, bb1);
+
+ /* Restore cfun. */
+ pop_cfun ();
+
+ return ret;
+}
+
+static bool
+write_before_read_in_function (struct ipa_ref *write, struct ipa_ref *read)
+{
+ basic_block w_bb = gimple_bb (write->stmt);
+ basic_block r_bb = gimple_bb (read->stmt);
+
+ if (w_bb != r_bb)
+ {
+ /*
+ * The dominator framework operates on cfun.
+ * Therefore we need to set cfun accordingly.
+ */
+ symtab_node *w_node = write->referring;
+ cgraph_node *w_cnode = dyn_cast<cgraph_node *> (w_node);
+ return bb1_dominates_bb2 (w_bb, r_bb, w_cnode);
+ }
+
+ gimple_stmt_iterator gsi;
+ for (gsi = gsi_start_bb (w_bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ if (gsi_stmt (gsi) == write->stmt)
+ return true;
+ if (gsi_stmt (gsi) == read->stmt)
+ return false;
+ }
+
+ /* Neither write nor read found it BB. */
+ gcc_assert (1);
+
+ return false;
+}
+
+/*
+ * DFS over callees and return if callee is a or b.
+ */
+static cgraph_node *
+find_cgraph_in_callee_set (cgraph_node *n, hash_set<cgraph_node *> set,
+ cgraph_node *a, cgraph_node *b)
+{
+ cgraph_edge *cs;
+ for (cs = n->callees; cs; cs = cs->next_callee)
+ {
+ cgraph_node *callee = cs->callee->function_symbol ();
+ if (dump_file)
+ fprintf (dump_file, "Child of %s: %s\n", n->dump_asm_name (),
+ callee->dump_asm_name ());
+ if (callee == a)
+ return a;
+ if (callee == b)
+ return b;
+ if (!set.contains (callee))
+ continue;
+ return find_cgraph_in_callee_set (callee, set, a, b);
+ }
+ return NULL;
+}
+
+/* Walks back along caller relations until main is found. */
+static cgraph_node *
+get_ancestor_main_dfs (hash_set<cgraph_node *> *visited,
+ vec<cgraph_node *> *path, cgraph_node *node)
+{
+ if (MAIN_NAME_P (DECL_NAME (node->decl)))
+ {
+ path->safe_push (node);
+ return node;
+ }
+
+ visited->add (node);
+
+ cgraph_edge *cs;
+ for (cs = node->callers; cs; cs = cs->next_caller)
+ {
+ cgraph_node *caller = cs->caller->function_symbol ();
+ if (!visited->contains (caller))
+ {
+ cgraph_node *main = get_ancestor_main_dfs (visited, path, caller);
+ if (main)
+ {
+ path->safe_push (node);
+ return main;
+ }
+ }
+ }
+ return NULL;
+}
+
+static cgraph_node *
+get_path_from_main_to (cgraph_node *node, vec<cgraph_node *> *path)
+{
+ hash_set<cgraph_node *> visited;
+ cgraph_node *main = get_ancestor_main_dfs (&visited, path, node);
+ visited.empty ();
+ return main;
+}
+
+/*
+ * Verifying that a stmt s1 is dominated by a stmt s2
+ * across function borders is not trivial with the available
+ * infrastructure (dominator algorithm on bb level plus cgraph).
+ * If we rule out external calls/callbacks, then we still need
+ * to guarantee a write on each possible path to the read.
+ *
+ * The implemented solution to this problem, which is of course
+ * too strict,
+ * but also not too compute/memory intensive is as follows:
+ *
+ * - Check if write is reachable by main () by only looking into
+ * the first bb in each function on the path.
+ * - All call stmts between main () and write must not possibly
+ * reach a read. We consider indirect call statements as
+ * possible reaching read (unless we can prove opposite).
+ *
+ * The external calls/callbacks are ruled out as follows:
+ *
+ * - all possible ancestors of read must not be external visible
+ * - all possible ancestors of read must not be function pointers
+ * - Something else?
+ */
+static bool
+write_before_read_across_function_borders (struct ipa_ref *write,
+ struct ipa_ref *read)
+{
+ symtab_node *w_node = write->referring;
+ cgraph_node *w_cnode = dyn_cast<cgraph_node *> (w_node);
+ symtab_node *r_node = read->referring;
+ cgraph_node *r_cnode = dyn_cast<cgraph_node *> (r_node);
+ cgraph_node *main;
+
+ /* Get main () function. */
+ vec<cgraph_node *> pw = vNULL;
+ main = get_path_from_main_to (w_cnode, &pw);
+ if (!main)
+ {
+ if (dump_file)
+ fprintf (dump_file, "main () is not ancestor of write -> skipping.\n");
+ return false;
+ }
+
+ vec<cgraph_node *> pr = vNULL;
+ cgraph_node *main_to_read = get_path_from_main_to (r_cnode, &pr);
+ if (!main_to_read)
+ {
+ if (dump_file)
+ fprintf (dump_file, "main () is not ancestor of read -> skipping.\n");
+ return false;
+ }
+
+ // TODO: is write guaranteed to happen?
+ // if it is not guaranteed to happen, we shouldn't modify anything!
+ // The very first approximation. There should be a path from main to w_cnode
+ // such that only the first basic block is actually inspected.
+ // Future work will involve looking at unconditional paths.
+ // I think right now, all paths are reachable from first basic block
+ if (!reach_nodes_via_bb1 (w_cnode))
+ return false;
+
+ int i;
+ cgraph_node *node_in_pr;
+ FOR_EACH_VEC_ELT (pr, i, node_in_pr)
+ {
+ // I think main has to be externally visible.
+ if (node_in_pr == main)
+ continue;
+
+ /* Assure that all paths to read are not externally visible. */
+ if (cgraph_externally_visible_p (node_in_pr, flag_whole_program))
+ {
+ if (dump_file)
+ fprintf (dump_file, "%s is externally visible... skipping\n",
+ node_in_pr->dump_asm_name ());
+ return false;
+ }
+
+ /* Assure that all paths to read are not
+ * used as function pointers. */
+ if (node_in_pr->address_taken)
+ {
+ if (dump_file)
+ fprintf (dump_file, "%s might be function pointer... skipping\n",
+ node_in_pr->dump_asm_name ());
+ return false;
+ }
+ }
+
+ cgraph_node *caller = main;
+ cgraph_node *node_in_pw;
+ FOR_EACH_VEC_ELT (pw, i, node_in_pw)
+ {
+ gcc_assert (w_cnode != r_cnode);
+ if (node_in_pw == r_cnode && path_exists (r_cnode, w_cnode))
+ {
+ return call_before_read (write, read);
+ }
+
+ if (node_in_pw == w_cnode && path_exists (w_cnode, r_cnode))
+ {
+ return write_before_call (write, read);
+ }
+
+ if (node_in_pw == main)
+ {
+ continue;
+ }
+
+ if (dump_file)
+ fprintf (dump_file, "get_nondominated_callees from %s to %s\n",
+ caller->dump_asm_name (), node_in_pw->dump_asm_name ());
+
+ bool exitEarly = false;
+ vec<cgraph_node *> non_dominated_callees
+ = get_nondominated_callees (caller, node_in_pw, &exitEarly);
+ if (exitEarly)
+ return false;
+ cgraph_node *non_dominated_callee;
+ int j;
+ FOR_EACH_VEC_ELT (non_dominated_callees, j, non_dominated_callee)
+ {
+ if (dump_file)
+ fprintf (dump_file, "callee %d %s\n", j,
+ non_dominated_callee->dump_asm_name ());
+ if (path_exists (non_dominated_callee, r_cnode))
+ {
+ return false;
+ }
+ }
+
+ caller = node_in_pw;
+ }
+ return true;
+}
+
+static vec<struct cgraph_node *>
+get_bb1_callees (cgraph_node *c, cgraph_node *w_cnode)
+{
+ vec<struct cgraph_node *> callees = vNULL;
+ if (fndecl_built_in_p (c->decl))
+ return vNULL;
+
+ if (dump_file)
+ fprintf (dump_file, "before get_untransformed_body %s\n",
+ c->dump_asm_name ());
+
+ if (!c->definition)
+ return vNULL;
+
+ push_cfun (DECL_STRUCT_FUNCTION (c->decl));
+
+ if (in_lto_p)
+ c->get_untransformed_body ();
+
+ pop_cfun ();
+
+ function *func = DECL_STRUCT_FUNCTION (c->decl);
+ /* Get first BB (after the fake entry BB). */
+ basic_block bb = ENTRY_BLOCK_PTR_FOR_FN (func)->next_bb;
+
+ 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_CALL)
+ continue;
+
+ tree callee_decl = gimple_call_fndecl (stmt);
+ cgraph_node *callee_node = cgraph_node::get (callee_decl);
+ if (!path_exists (callee_node, w_cnode))
+ continue;
+
+ callees.safe_push (callee_node);
+ }
+
+ return callees;
+}
+
+static bool
+reach_nodes_via_bb1_dfs (hash_set<cgraph_node *> *visited, cgraph_node *n1,
+ cgraph_node *n2)
+{
+ if (n1 == n2)
+ return true;
+
+ visited->add (n1);
+
+ vec<struct cgraph_node *> callees = get_bb1_callees (n1, n2);
+
+ int i;
+ cgraph_node *callee;
+ FOR_EACH_VEC_ELT (callees, i, callee)
+ {
+ if (!visited->contains (callee))
+ {
+ bool found = reach_nodes_via_bb1_dfs (visited, callee, n2);
+ if (found)
+ {
+ callees.release ();
+ return true;
+ }
+ }
+ }
+
+ return false;
+}
+
+bool
+reach_nodes_via_bb1 (cgraph_node *n2)
+{
+ vec<cgraph_node *> pr = vNULL;
+ cgraph_node *main = get_path_from_main_to (n2, &pr);
+ hash_set<cgraph_node *> visited;
+ bool path_exists = reach_nodes_via_bb1_dfs (&visited, main, n2);
+ visited.empty ();
+ pr.release ();
+ return path_exists;
+}
+
+static bool
+write_before_call (struct ipa_ref *write, struct ipa_ref *read)
+{
+ symtab_node *w_node = write->referring;
+ cgraph_node *w_cnode = dyn_cast<cgraph_node *> (w_node);
+ symtab_node *r_node = read->referring;
+ cgraph_node *r_cnode = dyn_cast<cgraph_node *> (r_node);
+
+ gcc_assert (path_exists (w_cnode, r_cnode));
+ gcc_assert (w_cnode != r_cnode);
+
+ basic_block w_bb = gimple_bb (write->stmt);
+ basic_block r_bb = gimple_bb (read->stmt);
+
+ if (in_lto_p)
+ {
+ w_cnode->get_untransformed_body ();
+ }
+
+ function *func = DECL_STRUCT_FUNCTION (w_cnode->decl);
+ basic_block c_bb;
+ vec<struct cgraph_node *> callees = vNULL;
+ FOR_EACH_BB_FN (c_bb, func)
+ {
+ bool self_dominates = w_bb == c_bb;
+ bool w_bb_dominates_c_bb = bb1_dominates_bb2 (w_bb, c_bb, w_cnode);
+ if (w_bb_dominates_c_bb && !self_dominates)
+ continue;
+
+ for (gimple_stmt_iterator gsi = gsi_start_bb (c_bb); !gsi_end_p (gsi);
+ gsi_next (&gsi))
+ {
+ gimple *stmt = gsi_stmt (gsi);
+
+ if (stmt == write->stmt)
+ {
+ break;
+ }
+
+ if (gimple_code (stmt) != GIMPLE_CALL)
+ {
+ continue;
+ }
+ if (dump_file)
+ print_gimple_stmt (dump_file, stmt, 0, TDF_NONE);
+ tree rhs = gimple_op (stmt, 1);
+
+ if (rhs && TREE_CODE (rhs) == POINTER_TYPE)
+ return false;
+
+ tree callee_decl = gimple_call_fndecl (stmt);
+ if (!callee_decl)
+ return false;
+
+ cgraph_node *callee_node = cgraph_node::get (callee_decl);
+ const char *identifier
+ = IDENTIFIER_POINTER (DECL_NAME (callee_node->decl));
+ const char *sigsetjmp = "sigsetjmp";
+ if (strstr (identifier, sigsetjmp) != NULL)
+ return false;
+
+ if (fndecl_built_in_p (callee_node->decl))
+ continue;
+
+ if (dump_file)
+ fprintf (dump_file, "found callee %s\n",
+ callee_node->dump_asm_name ());
+ callees.safe_push (callee_node);
+ }
+ }
+ cgraph_node *callee;
+ int i;
+ FOR_EACH_VEC_ELT (callees, i, callee)
+ {
+ if (path_exists (callee, r_cnode))
+ {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static bool
+call_before_read (struct ipa_ref *write, struct ipa_ref *read)
+{
+ symtab_node *w_node = write->referring;
+ cgraph_node *w_cnode = dyn_cast<cgraph_node *> (w_node);
+ symtab_node *r_node = read->referring;
+ cgraph_node *r_cnode = dyn_cast<cgraph_node *> (r_node);
+
+ gcc_assert (path_exists (r_cnode, w_cnode));
+ gcc_assert (w_cnode != r_cnode);
+
+ basic_block w_bb = gimple_bb (write->stmt);
+ basic_block r_bb = gimple_bb (read->stmt);
+
+ if (in_lto_p)
+ r_cnode->get_untransformed_body ();
+
+ function *func = DECL_STRUCT_FUNCTION (r_cnode->decl);
+ basic_block c_bb;
+ FOR_EACH_BB_FN (c_bb, func)
+ {
+ bool self_dominates = c_bb == r_bb;
+ bool call_dominates_read = bb1_dominates_bb2 (c_bb, r_bb, r_cnode);
+ if (!call_dominates_read && !self_dominates)
+ continue;
+
+ for (gimple_stmt_iterator gsi = gsi_start_bb (c_bb); !gsi_end_p (gsi);
+ gsi_next (&gsi))
+ {
+ gimple *stmt = gsi_stmt (gsi);
+
+ // self dominance
+ if (stmt == read->stmt)
+ break;
+
+ if (gimple_code (stmt) != GIMPLE_CALL)
+ continue;
+
+ if (dump_file)
+ print_gimple_stmt (dump_file, stmt, 0, TDF_NONE);
+ tree rhs = gimple_op (stmt, 1);
+ if (TREE_CODE (rhs) == POINTER_TYPE)
+ return false;
+ tree callee_decl = gimple_call_fndecl (stmt);
+
+ cgraph_node *callee_node = cgraph_node::get (callee_decl);
+ const char *identifier
+ = IDENTIFIER_POINTER (DECL_NAME (callee_node->decl));
+ const char *sigsetjmp = "sigsetjmp";
+ if (strstr (identifier, sigsetjmp) != NULL)
+ return false;
+
+ if (path_exists (callee_node, w_cnode))
+ return true;
+ }
+ }
+ return false;
+}
+
+static bool
+write_before_read (struct ipa_ref *write, struct ipa_ref *read)
+{
+ symtab_node *w_node = write->referring;
+ cgraph_node *w_cnode = dyn_cast<cgraph_node *> (w_node);
+ symtab_node *r_node = read->referring;
+ cgraph_node *r_cnode = dyn_cast<cgraph_node *> (r_node);
+
+ if (w_cnode == r_cnode)
+ /* Within the same function. */
+ return write_before_read_in_function (write, read);
+
+ /* Not within the same function. */
+ return write_before_read_across_function_borders (write, read);
+}
+
+static bool
+write_before_all_reads (struct ipa_ref *write, const ipa_ref_vec &reads)
+{
+ int i;
+ struct ipa_ref *read;
+
+ FOR_EACH_VEC_ELT (reads, i, read)
+ {
+ load_function_body_of_ipa_ref (read);
+ if (!write_before_read (write, read))
+ return false;
+ }
+ return true;
+}
+
+static void
+propagate_constant_to_read (tree write_val, struct ipa_ref *ref,
+ hash_set<cgraph_node *> *func)
+{
+ gcc_assert (ref->use == IPA_REF_LOAD);
+ load_function_body_of_ipa_ref (ref);
+
+ gimple *read_stmt = ref->stmt;
+
+ gcc_assert (gimple_code (read_stmt) == GIMPLE_ASSIGN);
+ gcc_assert (gimple_num_ops (read_stmt) == 2);
+
+ tree old_lhs = gimple_op (read_stmt, 0);
+ symtab_node *r_node = ref->referring;
+ cgraph_node *r_cnode = dyn_cast<cgraph_node *> (r_node);
+
+ // if (!func->contains (r_cnode)) func->add (r_cnode);
+ cgraph_node **possible_clone = func_to_clone->get (r_cnode);
+ if (!possible_clone)
+ {
+ const char *suffix = "test";
+ // callers has to be vNULL, otherwise, we will be
+ // analyzing clones...
+ // and we don't want that...
+ // but that means that we will need to update the callers
+ // later... in update_callgraph
+ cgraph_node *clone
+ = r_cnode->create_version_clone_with_body (vNULL, NULL, NULL, NULL,
+ NULL, suffix, NULL);
+ clone->get_untransformed_body ();
+ func_to_clone->put (r_cnode, clone);
+ }
+
+ possible_clone = func_to_clone->get (r_cnode);
+ cgraph_node *clone = *possible_clone;
+
+ // Build new stmt and replace old.
+ gimple_stmt_iterator gsi;
+ basic_block bb;
+ // Let's create a clone with body here...
+ // The clone should not have callers as
+ // to not interfere with the current
+ // analysis.
+ // The callers will be set at the end...
+
+ push_cfun (DECL_STRUCT_FUNCTION (clone->decl));
+ function *clone_func = DECL_STRUCT_FUNCTION (clone->decl);
+ bool found = false;
+ FOR_EACH_BB_FN (bb, clone_func)
+ {
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple *stmt = gsi_stmt (gsi);
+ if (gimple_code (stmt) != GIMPLE_ASSIGN)
+ continue;
+ tree old_val_clone = gimple_op (stmt, 1);
+ tree lhs = gimple_op (stmt, 0);
+
+ // TODO: what happens when it is not a variable decl?
+ // This might actually be the source of imprecision
+ if (TREE_CODE (old_val_clone) != VAR_DECL)
+ continue;
+
+ tree old_val = gimple_op (read_stmt, 1);
+ if (IDENTIFIER_POINTER (DECL_NAME (old_val_clone))
+ != IDENTIFIER_POINTER (DECL_NAME (old_val)))
+ continue;
+
+ found = true;
+
+ // REPLACE!!!
+ gimple_stmt_iterator gsi2 = gsi_for_stmt (stmt);
+ tree new_lhs = make_ssa_name (TREE_TYPE (lhs));
+ gimple *new_read_stmt = gimple_build_assign (new_lhs, write_val);
+ gsi_insert_before (&gsi2, new_read_stmt, GSI_SAME_STMT);
+
+ gimple *use_stmt;
+ imm_use_iterator use_iter;
+ FOR_EACH_IMM_USE_STMT (use_stmt, use_iter, lhs)
+ {
+ use_operand_p use_p;
+ FOR_EACH_IMM_USE_ON_STMT (use_p, use_iter)
+ SET_USE (use_p, new_lhs);
+ update_stmt (use_stmt);
+ }
+ }
+
+ if (found)
+ break;
+ }
+ gcc_assert (found);
+ pop_cfun ();
+}
+
+static bool
+ipa_initcall_get_writes_and_reads (varpool_node *vnode, ipa_ref_vec *writes,
+ ipa_ref_vec *reads)
+{
+ int i;
+ struct ipa_ref *ref;
+
+ if (dump_file)
+ fprintf (dump_file, "%s for variable '%s'.\n", __func__, vnode->name ());
+
+ /* Only IPA_REF_STORE and IPA_REF_LOAD left. */
+ for (i = 0; vnode->iterate_referring (i, ref); i++)
+ {
+ symtab_node *f_node = ref->referring;
+ cgraph_node *f_cnode = dyn_cast<cgraph_node *> (f_node);
+
+ if (!f_cnode)
+ {
+ if (dump_file)
+ fprintf (dump_file,
+ "skipping variable %s due to static initialization\n",
+ vnode->name ());
+ return false;
+ }
+ // it is possible that f_cnode is NULL if the dyn_cast fails.
+ // If the dyn_cast fails, this is an example of static initialization.
+ const char *identifier = IDENTIFIER_POINTER (DECL_NAME (f_cnode->decl));
+ // This is the suffix we are adding to our clones.
+ // Therefore, if we find the suffix in the identifier,
+ // that means that we found a variable in a clone and
+ // we would like to skip it.
+ // TODO: make this a global static for easier changes...
+ const char *suffix = "test.0";
+ if (strstr (identifier, suffix) != NULL)
+ continue;
+
+ if (ref->use == IPA_REF_STORE)
+ writes->safe_push (ref);
+
+ if (ref->use == IPA_REF_LOAD)
+ reads->safe_push (ref);
+ }
+ return true;
+}
+
+static void
+propagate_constant_to_reads (tree write_val, const ipa_ref_vec &reads_original,
+ hash_set<cgraph_node *> *funcs)
+{
+ /* Iterate over reads and replace them by constant. */
+ struct ipa_ref *ref;
+ int i;
+ FOR_EACH_VEC_ELT (reads_original, i, ref)
+ {
+ propagate_constant_to_read (write_val, ref, funcs);
+ }
+}
+
+/*
+ * Extracts the assigned constant, iff the given statement
+ * is a constant assignment. Returns NULL_TREE otherwise.
+ */
+static tree
+extract_constant_from_initcall_write (struct ipa_ref *write)
+{
+ symtab_node *f_node = write->referring;
+ cgraph_node *f_cnode = dyn_cast<cgraph_node *> (f_node);
+
+ tree decl = f_cnode->decl;
+ if (TREE_CODE (decl) != FUNCTION_DECL)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Not function decl -> skipping.\n");
+ return NULL_TREE;
+ }
+
+ if (!f_cnode->has_gimple_body_p () && dump_file)
+ fprintf (dump_file, "Does NOT have gimple body!\n");
+ if (f_cnode->inlined_to && dump_file)
+ fprintf (dump_file, "Inlined To\n");
+
+ if (dump_file)
+ {
+ fprintf (dump_file, "%s: for writer gimple:\n", __func__);
+ dump_vnode_ipa_ref (write);
+ }
+
+ /* Get the write function's body. */
+ load_function_body_of_ipa_ref (write);
+
+ gimple *stmt = write->stmt;
+
+ /* Verify that we have an assignment. */
+ if (gimple_code (stmt) != GIMPLE_ASSIGN)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Write stmt not assignment -> skipping.\n");
+ return NULL_TREE;
+ }
+
+ /* Check if write's LHS (vnode) is not volatile. */
+ tree lhs = gimple_assign_lhs (stmt);
+ if (TREE_THIS_VOLATILE (TREE_TYPE (lhs)))
+ {
+ if (dump_file)
+ fprintf (dump_file, "Variable volatile -> skipping.\n");
+ return NULL_TREE;
+ }
+
+ /* Check if RHS of write stmt is constant. */
+ if (!gimple_assign_is_single_const (stmt))
+ {
+ if (dump_file)
+ {
+ fprintf (dump_file, "Found non-const operands.\n");
+ }
+ return NULL_TREE;
+ }
+
+ /* Extract the constant. */
+ tree write_val = gimple_op (stmt, 1);
+
+ if (dump_file)
+ {
+ fprintf (dump_file, "Const op:\n");
+ dump_node (write_val, TDF_DETAILS, dump_file);
+ }
+
+ return write_val;
+}
+
+static void
+ipa_initcall_cp_execute_for_var (varpool_node *vnode,
+ hash_set<cgraph_node *> *update_functions)
+{
+ ipa_ref_vec writes = vNULL;
+ ipa_ref_vec reads = vNULL;
+ struct ipa_ref *write;
+ tree write_val;
+ gimple_stmt_iterator gsi;
+ bool remove_permanently;
+
+ if (dump_file)
+ fprintf (dump_file, "%s for variable '%s'.\n", __func__, vnode->name ());
+
+ if (dump_file)
+ {
+ dump_node (vnode->decl, TDF_DETAILS, dump_file);
+ }
+
+ /* Variable must not be externally visible. */
+ if (vnode->externally_visible_p ())
+ {
+ if (dump_file)
+ fprintf (dump_file, "\texternally visible "
+ "-> skipping\n");
+ return;
+ }
+
+ /* All refs must be explicit. */
+ if (!vnode->all_refs_explicit_p ())
+ {
+ if (dump_file)
+ fprintf (dump_file, "Not explicit variable refs "
+ "-> skipping.\n");
+ return;
+ }
+
+ /* Check if any ref->use is IPA_REF_ALIAS. */
+ if (vnode->has_aliases_p ())
+ {
+ if (dump_file)
+ fprintf (dump_file, "Found IPA_REF_ALIAS -> skipping.\n");
+ return;
+ }
+
+ /* Check if any ref->use is IPA_REF_ADDR. */
+ if (symtab_node_address_matters_p (vnode))
+ {
+ if (dump_file)
+ fprintf (dump_file, "Found IPA_REF_ADDR -> skipping.\n");
+ return;
+ }
+
+ /* We don't touch arrays. */
+ if (TREE_CODE (TREE_TYPE (vnode->decl)) == ARRAY_TYPE)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Variable is array -> skipping.\n");
+ return;
+ }
+
+ /* We don't touch structs. */
+ if (TREE_CODE (TREE_TYPE (vnode->decl)) == RECORD_TYPE)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Variable is struct -> skipping.\n");
+ return;
+ }
+
+ /* We don't touch unions. */
+ if (TREE_CODE (TREE_TYPE (vnode->decl)) == UNION_TYPE)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Variable is union -> skipping.\n");
+ return;
+ }
+
+ /* Get all refs (must be REF_STORE or REF_LOAD). */
+ bool continue_work
+ = ipa_initcall_get_writes_and_reads (vnode, &writes, &reads);
+ if (!continue_work)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Static initialization -> skipping.\n");
+ writes.release ();
+ reads.release ();
+ return;
+ }
+
+ if (writes.length () > 1)
+ {
+ /* More than one writer. */
+ if (dump_file)
+ fprintf (dump_file, "More than one writer -> skipping.\n");
+ writes.release ();
+ reads.release ();
+ return;
+ }
+ else if (writes.length () < 1)
+ {
+ /* No writer. */
+ if (dump_file)
+ fprintf (dump_file, "No writer -> skipping.\n");
+ writes.release ();
+ reads.release ();
+ return;
+ }
+
+ /*
+ * Note:
+ * Limiting ourselfs to only one write is not necessary in general,
+ * but good enough to address the typical init () case.
+ * Big advantage is, that it makes the following code much easier.
+ *
+ * TODO: I believe that if we create clones, we might get two writes
+ * Investigate
+ */
+
+ /* Get (only) write ref. */
+ write = writes.pop ();
+
+ /* Check if write's RHS is a constant and get it. */
+ write_val = extract_constant_from_initcall_write (write);
+ if (write_val == NULL_TREE)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Write's RHS is not constant"
+ " -> skipping.\n");
+ writes.release ();
+ reads.release ();
+ return;
+ }
+
+ /* Assure all reads are after the write. */
+ if (!write_before_all_reads (write, reads))
+ {
+ if (dump_file)
+ fprintf (dump_file, "Write not guaranteed "
+ "to be before read -> skipping.\n");
+ writes.release ();
+ reads.release ();
+ return;
+ }
+
+ /* Propagate constant to reads. */
+ if (!flag_initcall_cp_dryrun)
+ propagate_constant_to_reads (write_val, reads, update_functions);
+
+ /* Finally remove the write. */
+ gsi = gsi_for_stmt (write->stmt);
+ remove_permanently = false; // XXX: fails with true?
+ // gsi_remove (&gsi, remove_permanently);
+
+ if (dump_file)
+ fprintf (dump_file, "Eliminated variable '%s'.\n\n", vnode->name ());
+
+ writes.release ();
+ reads.release ();
+}
+
+bool
+update_callgraph (cgraph_node *const &r_cnode, cgraph_node **clone_ptr, void *)
+{
+ vec<cgraph_edge *> callers = r_cnode->collect_callers ();
+ cgraph_node *clone = *clone_ptr;
+ cgraph_edge *e;
+ int i;
+ profile_count count = r_cnode->count;
+
+ FOR_EACH_VEC_ELT (callers, i, e)
+ e->redirect_callee (clone);
+
+ /*
+ for (e = r_cnode->callees; e; e=e->next_callee)
+ e->clone (clone, e->call_stmt, e->lto_stmt_uid, count, count, true);
+
+ for (e = r_cnode->indirect_calls; e; e=e->next_callee)
+ e->clone (clone, e->call_stmt, e->lto_stmt_uid, count, count, true);
+ */
+ for (e = clone->callers; e; e = e->next_caller)
+ {
+ e->caller->get_untransformed_body ();
+ function *inner_function = DECL_STRUCT_FUNCTION (e->caller->decl);
+ gimple_call_set_fndecl (e->call_stmt, clone->decl);
+ maybe_clean_eh_stmt_fn (inner_function, e->call_stmt);
+ }
+
+ r_cnode->skip_ipa_cp = true;
+ // r_cnode->remove ();
+ push_cfun (DECL_STRUCT_FUNCTION (r_cnode->decl));
+
+ if (dump_file)
+ fprintf (dump_file, "dumping function %s\n", r_cnode->dump_asm_name ());
+ function *func = DECL_STRUCT_FUNCTION (r_cnode->decl);
+ basic_block bb;
+ FOR_EACH_BB_FN (bb, func)
+ {
+ for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi);
+ gsi_next (&gsi))
+ {
+ gimple *stmt = gsi_stmt (gsi);
+ if (dump_file)
+ print_gimple_stmt (dump_file, stmt, 0, TDF_NONE);
+ }
+ }
+ if (dom_info_available_p (CDI_DOMINATORS))
+ free_dominance_info (CDI_DOMINATORS);
+ pop_cfun ();
+ return true;
+}
+
+static unsigned int
+ipa_initcall_cp_execute (void)
+{
+ varpool_node *vnode;
+
+ clone_num_suffixes1 = new hash_map<const char *, unsigned>;
+ hash_set<cgraph_node *> update_functions;
+ func_to_clone = new hash_map<cgraph_node *, cgraph_node *>;
+ FOR_EACH_VARIABLE (vnode)
+ {
+ ipa_initcall_cp_execute_for_var (vnode, &update_functions);
+ }
+
+ if (!flag_initcall_cp_dryrun)
+ func_to_clone->traverse<void *, update_callgraph> (NULL);
+
+ delete clone_num_suffixes1;
+ delete func_to_clone;
+
+ return 0;
+}
+
+namespace {
+
+const pass_data pass_data_ipa_initcall_cp = {
+ IPA_PASS,
+ "initcall_cp",
+ OPTGROUP_NONE,
+ TV_NONE,
+ (PROP_cfg | PROP_ssa),
+ 0,
+ 0,
+ 0,
+ (TODO_update_ssa | TODO_cleanup_cfg | TODO_dump_symtab
+ | TODO_rebuild_cgraph_edges | TODO_discard_function),
+};
+
+class pass_ipa_initcall_cp : public ipa_opt_pass_d
+{
+public:
+ pass_ipa_initcall_cp (gcc::context *ctxt)
+ : ipa_opt_pass_d (pass_data_ipa_initcall_cp, ctxt, NULL, NULL, NULL, NULL,
+ NULL, NULL, 0, NULL, NULL)
+ {}
+
+ /* opt_pass methods: */
+ virtual bool gate (function *)
+ {
+ return flag_initcall_cp || flag_initcall_cp_dryrun;
+ }
+
+ virtual unsigned int execute (function *)
+ {
+ return ipa_initcall_cp_execute ();
+ }
+
+}; // class pass_ipa_initcall_cp
+
+} // namespace
+
+ipa_opt_pass_d *
+make_pass_ipa_initcall_cp (gcc::context *ctxt)
+{
+ return new pass_ipa_initcall_cp (ctxt);
+}
diff --git a/gcc/passes.def b/gcc/passes.def
index 798a391..350a4fc 100644
--- a/gcc/passes.def
+++ b/gcc/passes.def
@@ -146,6 +146,7 @@ along with GCC; see the file COPYING3. If not see
NEXT_PASS (pass_ipa_profile);
NEXT_PASS (pass_ipa_icf);
NEXT_PASS (pass_ipa_devirt);
+ NEXT_PASS (pass_ipa_initcall_cp);
NEXT_PASS (pass_ipa_cp);
NEXT_PASS (pass_ipa_sra);
NEXT_PASS (pass_ipa_cdtor_merge);
diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h
index a987661..6de60fe 100644
--- a/gcc/tree-pass.h
+++ b/gcc/tree-pass.h
@@ -498,6 +498,7 @@ extern ipa_opt_pass_d *make_pass_ipa_fn_summary
(gcc::context *ctxt);
extern ipa_opt_pass_d *make_pass_ipa_inline (gcc::context *ctxt);
extern simple_ipa_opt_pass *make_pass_ipa_free_lang_data (gcc::context *ctxt);
extern simple_ipa_opt_pass *make_pass_ipa_free_fn_summary (gcc::context *ctxt);
+extern ipa_opt_pass_d *make_pass_ipa_initcall_cp (gcc::context *ctxt);
extern ipa_opt_pass_d *make_pass_ipa_cp (gcc::context *ctxt);
extern ipa_opt_pass_d *make_pass_ipa_sra (gcc::context *ctxt);
extern ipa_opt_pass_d *make_pass_ipa_icf (gcc::context *ctxt);
On 2019-11-29 4:21 p.m., Erick Ochoa wrote:
>
> Hello,
>
> my name is Erick and I am working in a link-time-optimization pass named
> ipa-initcall-cp. It is called ipa-initcall-cp because it propagates constant
> values written to variables with static lifetimes (such as ones initialized in
> initialization functions). ipa-initcall-cp has to be located after
> ipa-whole-program-visibility to determine which functions have external
> visibility and before ipa-cp because ipa-cp can take advantage of our
> transformation.
>
> I have attached a patch and test cases. I have applied and tested the patch
> against:
>
> commit 17a2c588c29f089d3c2a36df47175bbdf376e399
> Date: Wed Nov 27 00:23:39 2019 +0000
> git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@278752
> 138bc75d-0d04-0410-961f-82ee72b054a4
>
> In order to run the test cases:
> * apply patch to gcc
> * modify Makefile to point to modified gcc
> * make
>
> The test cases test the order in which a write can happen regarding a read
> (before or after) and whether the write/read happen in a function being called
> by the function that reads/writes. The test cases succeed when the variables
> prefixed with SUCCEED_* have been propagated and when the variables prefixed
> with FAILED_* have NOT been propagated. To quickly determine which variables
> have been propagated, you can do the following command:
>
> grep 'Eliminated' test.wpa.071i.initcall_cp
> # SUCCESS_{0,1,2,3}* should be eliminated
>
> This compiler pass is able to compile non-trivial code, but it does not
> compile
> arbitrary valid code (sometimes linking fails). We are using
> create_clone_version_with_body for creating the clones. The reasoning behind
> this is that we want clones to have a body so that we can modify it. I have
> been told that `create_version_clone_with_body` are used mainly in IPA passes
> that are not part of INSERT_PASSES_AFTER (all_regular_ipa_passes).
>
> Question #1: Can someone please tell me what would be the best kind of clones
> to use in this use case?
> Question #2: I found out that clones produced with
> create_clone_version_with_body are not themselves versionable. What is the
> reason behind this?
> Question #3: I have added a flag to cgraph_nodes to skip ipa-cp. This flag is
> true for the original functions which have been removed from the call graph.
> If this flag is removed, then cgraph_nodes removed from the call graph will
> trigger an assertion in ipa-cp (ipa-cp.c:1195). I would like to not have to
> add this flag to cgraph_node but I am not sure what to do.
>
> Please note:
> * The patch is also included in the attachments file (because I've been having
> issues with how e-mail clients format my content. Note, that this is a text
> only html, but the patch might have rows longer than 80 characters (due to the
> + sign)
> and my e-mail client is splitting lines.
> * The patch still does not meet the coding standards, I'll be working on that.
> * The patch is included here (and the attachments) and the tests are included
> as a attachments. I'll be working on integrating the tests as part of the
> testing suite
>
>
> Thanks!
>
> diff --git a/gcc/Makefile.in b/gcc/Makefile.in
> index 7d3c132..ad8d998 100644
> --- a/gcc/Makefile.in
> +++ b/gcc/Makefile.in
> @@ -1370,6 +1370,7 @@ OBJS = \
> internal-fn.o \
> ipa-cp.o \
> ipa-sra.o \
> + ipa-initcall-cp.o \
> ipa-devirt.o \
> ipa-fnsummary.o \
> ipa-polymorphic-call.o \
> diff --git a/gcc/cgraph.c b/gcc/cgraph.c
> index 1f7a5c5..bc51681 100644
> --- a/gcc/cgraph.c
> +++ b/gcc/cgraph.c
> @@ -287,6 +287,7 @@ symbol_table::create_empty (void)
> node->type = SYMTAB_FUNCTION;
> node->frequency = NODE_FREQUENCY_NORMAL;
> node->count_materialization_scale = REG_BR_PROB_BASE;
> + node->skip_ipa_cp = false;
> cgraph_count++;
>
> return node;
> @@ -3515,6 +3516,7 @@ cgraph_node::get_untransformed_body (void)
> name = lto_get_decl_name_mapping (file_data, name);
> struct lto_in_decl_state *decl_state
> = lto_get_function_in_decl_state (file_data, decl);
> + gcc_assert (decl_state != NULL);
>
> cgraph_node *origin = this;
> while (origin->clone_of)
> diff --git a/gcc/cgraph.h b/gcc/cgraph.h
> index 0d2442c..82725ed 100644
> --- a/gcc/cgraph.h
> +++ b/gcc/cgraph.h
> @@ -899,6 +899,8 @@ struct GTY((tag ("SYMTAB_FUNCTION"))) cgraph_node :
> public symtab_node
> {
> friend class symbol_table;
>
> + bool skip_ipa_cp;
> +
> /* Remove the node from cgraph and all inline clones inlined into it.
> Skip however removal of FORBIDDEN_NODE and return true if it needs to be
> removed. This allows to call the function from outer loop walking clone
> diff --git a/gcc/common.opt b/gcc/common.opt
> index 404b6aa..fb662ed 100644
> --- a/gcc/common.opt
> +++ b/gcc/common.opt
> @@ -3344,4 +3344,7 @@ fipa-ra
> Common Report Var(flag_ipa_ra) Optimization
> Use caller save register across calls if possible.
>
> +finitcall-cp
> +Common Report Var(flag_initcall_cp) TBD.
> +
> ; This comment is to ensure we retain the blank line above.
> diff --git a/gcc/ipa-cp.c b/gcc/ipa-cp.c
> index 31a98a3..72d1595 100644
> --- a/gcc/ipa-cp.c
> +++ b/gcc/ipa-cp.c
> @@ -1185,7 +1185,7 @@ initialize_node_lattices (struct cgraph_node *node)
>
> gcc_checking_assert (node->has_gimple_body_p ());
>
> - if (!ipa_get_param_count (info))
> + if (!ipa_get_param_count (info) || node->skip_ipa_cp)
> disable = true;
> else if (node->local)
> {
> diff --git a/gcc/ipa-initcall-cp.c b/gcc/ipa-initcall-cp.c
> new file mode 100644
> index 0000000..8f1c4ab
> --- /dev/null
> +++ b/gcc/ipa-initcall-cp.c
> @@ -0,0 +1,1289 @@
> +/* Initcall constant propagation pass. */
> +
> +#include "config.h"
> +#include "system.h"
> +#include "coretypes.h"
> +#include "backend.h"
> +#include "tree.h"
> +#include "tree-eh.h"
> +#include "gimple.h"
> +#include "gimple-expr.h"
> +#include "gimple-iterator.h"
> +#include "predict.h"
> +#include "alloc-pool.h"
> +#include "tree-pass.h"
> +#include "cgraph.h"
> +#include "diagnostic.h"
> +#include "fold-const.h"
> +#include "gimple-fold.h"
> +#include "symbol-summary.h"
> +#include "tree-vrp.h"
> +#include "ipa-prop.h"
> +#include "tree-pretty-print.h"
> +#include "tree-inline.h"
> +#include "ipa-fnsummary.h"
> +#include "ipa-utils.h"
> +#include "tree-ssa-ccp.h"
> +#include "stringpool.h"
> +#include "attribs.h"
> +#include "gimple-pretty-print.h"
> +#include "ssa.h"
> +
> +static bool bb1_dominates_bb2 (basic_block, basic_block, cgraph_node*);
> +static bool write_before_call (struct ipa_ref *, struct ipa_ref *);
> +static bool call_before_read(struct ipa_ref *, struct ipa_ref *);
> +static hash_map<const char *, unsigned> *clone_num_suffixes1;
> +static hash_map<cgraph_node*, cgraph_node*> *func_to_clone;
> +
> +static bool
> +comdat_can_be_unshared_p_1 (symtab_node *node)
> +{
> + if (!node->externally_visible)
> + return true;
> + if (node->address_can_be_compared_p ())
> + {
> + struct ipa_ref *ref;
> +
> + for (unsigned int i = 0; node->iterate_referring (i, ref); i++)
> + if (ref->address_matters_p ())
> + return false;
> + }
> +
> + /* If the symbol is used in some weird way,
> + * better to not touch it. */
> + if (node->force_output)
> + return false;
> +
> + /* Explicit instantiations needs to be output when possibly
> + used externally. */
> + if (node->forced_by_abi
> + && TREE_PUBLIC (node->decl)
> + && (node->resolution != LDPR_PREVAILING_DEF_IRONLY
> + && !flag_whole_program))
> + return false;
> +
> + /* Non-readonly and volatile variables cannot be duplicated. */
> + if (is_a <varpool_node *> (node)
> + && (!TREE_READONLY (node->decl)
> + || TREE_THIS_VOLATILE (node->decl)))
> + return false;
> + return true;
> +}
> +
> +/* COMDAT functions must be shared only if they have address taken,
> + otherwise we can produce our own private implementation with
> + -fwhole-program.
> + Return true when turning COMDAT function static cannot lead to wrong
> + code when the resulting object links with a library defining same
> + COMDAT.
> +
> + Virtual functions do have their addresses taken from the vtables,
> + but in C++ there is no way to compare their addresses
> + for equality. */
> +
> +static bool
> +comdat_can_be_unshared_p (symtab_node *node)
> +{
> + if (!comdat_can_be_unshared_p_1 (node))
> + return false;
> + if (node->same_comdat_group)
> + {
> + symtab_node *next;
> +
> + /* If more than one function is in the same COMDAT group, it must
> + be shared even if just one function in the comdat group has
> + address taken. */
> + for (next = node->same_comdat_group;
> + next != node; next = next->same_comdat_group)
> + if (!comdat_can_be_unshared_p_1 (next))
> + return false;
> + }
> + return true;
> +}
> +
> +/* Return true when function NODE should
> + * be considered externally visible. */
> +
> +static bool
> +cgraph_externally_visible_p (struct cgraph_node *node,
> + bool whole_program)
> +{
> + while (node->transparent_alias && node->definition)
> + node = node->get_alias_target ();
> + if (!node->definition)
> + return false;
> + if (!TREE_PUBLIC (node->decl)
> + || DECL_EXTERNAL (node->decl))
> + return false;
> +
> + /* Do not try to localize built-in functions yet.
> + One of problems is that we
> + end up mangling their asm for
> + WHOPR that makes it impossible to call them
> + using the implicit built-in declarations
> + anymore. Similarly this enables
> + us to remove them as unreachable before
> + actual calls may appear during
> + expansion or folding. */
> + if (fndecl_built_in_p (node->decl))
> + return true;
> +
> + /* If linker counts on us, we must preserve the function. */
> + if (node->used_from_object_file_p ())
> + return true;
> + if (DECL_PRESERVE_P (node->decl))
> + return true;
> + if (lookup_attribute ("externally_visible",
> + DECL_ATTRIBUTES (node->decl)))
> + return true;
> + if (lookup_attribute ("noipa", DECL_ATTRIBUTES (node->decl)))
> + return true;
> + if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
> + && lookup_attribute ("dllexport",
> + DECL_ATTRIBUTES (node->decl)))
> + return true;
> + if (node->resolution == LDPR_PREVAILING_DEF_IRONLY)
> + return false;
> + /* When doing LTO or whole program, we can bring COMDAT functions
> + static.
> + This improves code quality and we know we will duplicate them at
> + most twice
> + (in the case that we are not using plugin and link with object
> + file implementing same COMDAT) */
> + if (((in_lto_p || whole_program) && !flag_incremental_link)
> + && DECL_COMDAT (node->decl)
> + && comdat_can_be_unshared_p (node))
> + return false;
> +
> + /* When doing link time optimizations,
> + * hidden symbols become local. */
> + if ((in_lto_p && !flag_incremental_link)
> + && (DECL_VISIBILITY (node->decl) == VISIBILITY_HIDDEN
> + || DECL_VISIBILITY (node->decl) == VISIBILITY_INTERNAL)
> + /* Be sure that node is defined in IR file, not in other object
> + file. In that case we don't set
> + used_from_other_object_file. */
> + && node->definition)
> + ;
> + else if (!whole_program)
> + return true;
> +
> + if (MAIN_NAME_P (DECL_NAME (node->decl)))
> + return true;
> +
> + return false;
> +}
> +
> +typedef vec <struct ipa_ref*> ipa_ref_vec;
> +
> +//XXX: Move to ipa-ref.h
> +static const char* stringify_ipa_ref_use(ipa_ref_use use)
> +{
> + switch (use) {
> + case IPA_REF_LOAD:
> + return "IPA_REF_LOAD";
> + break;
> + case IPA_REF_STORE:
> + return "IPA_REF_STORE";
> + break;
> + case IPA_REF_ADDR:
> + return "IPA_REF_ADDR";
> + break;
> + case IPA_REF_ALIAS:
> + return "IPA_REF_ALIAS";
> + break;
> + default:
> + return "<unknown>";
> + }
> +}
> +
> +static void
> +load_function_body_of_ipa_ref (cgraph_node* node)
> +{
> + if (in_lto_p)
> + {
> + cgraph_node *f_cnode2 = node->ultimate_alias_target ();
> + if (dump_file)
> + {
> + fprintf (dump_file, "%s: for function '%s'\n", __func__, \
> + f_cnode2->dump_asm_name ());
> + dump_node (f_cnode2->decl, TDF_DETAILS, dump_file);
> + }
> + f_cnode2->get_untransformed_body();
> + }
> +}
> +
> +static void
> +load_function_body_of_ipa_ref (struct ipa_ref* ref)
> +{
> + /* IPA passes don't get the function bodies during LTO. */
> + if (in_lto_p)
> + {
> + symtab_node *f_node = ref->referring;
> + cgraph_node *f_cnode = dyn_cast <cgraph_node *> (f_node);
> + load_function_body_of_ipa_ref (f_cnode);
> + }
> +}
> +
> +
> +static void
> +dump_vnode_ipa_ref (ipa_ref* ref)
> +{
> + fprintf (dump_file, \
> + "Reference type: %s\n", \
> + stringify_ipa_ref_use (ref->use));
> +
> + symtab_node *f_node = ref->referring;
> + fprintf (dump_file, \
> + "Reference function: %s\n", \
> + f_node->dump_asm_name ());
> +
> + fprintf (dump_file, "Gimple stmt (@0x%lx, lto_stmt_uid: %u):\n", \
> + (long)ref->stmt,
> + ref->lto_stmt_uid);
> + load_function_body_of_ipa_ref (ref);
> + print_gimple_stmt (dump_file, ref->stmt, 0, TDF_NONE);
> +}
> +
> +//XXX: Move to tree.h
> +static bool
> +tree_code_is_cst (tree op)
> +{
> + //XXX: use cprop_constant_p() here?
> + int code = TREE_CODE (op);
> + if (code == INTEGER_CST ||
> + code == REAL_CST ||
> + code == COMPLEX_CST ||
> + code == VECTOR_CST)
> + return true;
> + return false;
> +}
> +
> +/* Return true of all ops of assignment are constants. */
> +static bool
> +gimple_assign_is_single_const(gimple *stmt)
> +{
> + tree op;
> +
> + gcc_assert (gimple_code (stmt) == GIMPLE_ASSIGN);
> +
> + if (gimple_has_volatile_ops (stmt))
> + {
> + if (dump_file)
> + fprintf (dump_file, "has volatile ops!\n");
> + return false;
> + }
> +
> + if (gimple_num_ops (stmt) != 2)
> + {
> + if (dump_file)
> + fprintf (dump_file, "wrong num of ops: %u!\n", \
> + gimple_num_ops (stmt));
> + return false;
> + }
> +
> + op = gimple_op (stmt, 1);
> + if (!tree_code_is_cst (op))
> + {
> + if (dump_file)
> + fprintf (dump_file, "op is not cst!\n");
> + return false;
> + }
> +
> + return true;
> +}
> +
> +//XXX: Move to ipa-utils.c
> +//XXX: from/to could be const
> +static bool
> +path_exists_dfs (hash_set<cgraph_node*> *visited,
> + cgraph_node* current,
> + cgraph_node *target)
> +{
> + if (current == target)
> + return true;
> +
> + visited->add (current);
> +
> + cgraph_edge *cs;
> + for (cs = current->callees; cs; cs = cs->next_callee)
> + {
> + cgraph_node *callee = cs->callee->function_symbol ();
> + if (!visited->contains (callee))
> + {
> + if (path_exists_dfs (visited, callee, target))
> + {
> + return true;
> + }
> + }
> + }
> + return false;
> +}
> +
> +//XXX: Move to ipa-utils.c
> +//XXX: from/to could be const
> +static bool
> +path_exists (cgraph_node* from, cgraph_node *to)
> +{
> + hash_set<cgraph_node*> visited;
> + bool found_path = path_exists_dfs (&visited, from, to);
> + visited.empty ();
> +
> + if (dump_file)
> + {
> + fprintf (dump_file, "Found ");
> + if (!found_path)
> + fprintf (dump_file, "*no* ");
> + fprintf (dump_file, \
> + "path from %s to %s.\n", \
> + from->name (), \
> + to->name ());
> + }
> + return found_path;
> +}
> +
> +vec<struct cgraph_node*>
> +get_nondominated_callees(cgraph_node* caller, cgraph_node* callee)
> +{
> + // assumptions:
> + // * there is a callsite from caller to callee
> +
> + if (in_lto_p)
> + caller->get_untransformed_body ();
> +
> + function *func = DECL_STRUCT_FUNCTION (caller->decl);
> + basic_block bb;
> + bool found = false;
> + FOR_EACH_BB_FN(bb, func)
> + {
> + 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_CALL)
> + continue;
> +
> + tree callee_decl = gimple_call_fndecl (stmt);
> + cgraph_node *callee_node = cgraph_node::get (callee_decl);
> + if (callee_node != callee)
> + continue;
> +
> + found = true;
> + }
> + if (found) break;
> + }
> +
> + gcc_assert (found);
> +
> + // At this point in the program, we hold a valid bb.
> + // The callee is located
> + vec<struct cgraph_node*> callees = vNULL;
> + basic_block bb_c;
> + FOR_EACH_BB_FN(bb_c, func)
> + {
> + bool self_dominates = bb == bb_c;
> + bool bb_dominates_bbc = bb1_dominates_bb2(bb, bb_c, caller);
> + if (bb_dominates_bbc && !self_dominates) continue;
> +
> + for (gimple_stmt_iterator gsi = gsi_start_bb (bb_c); \
> + !gsi_end_p (gsi); \
> + gsi_next (&gsi))
> + {
> + gimple *stmt = gsi_stmt (gsi);
> + if (gimple_code (stmt) != GIMPLE_CALL)
> + continue;
> +
> + tree callee_decl = gimple_call_fndecl (stmt);
> + cgraph_node *callee_node = cgraph_node::get (callee_decl);
> +
> + if (fndecl_built_in_p (callee_node->decl))
> + continue;
> +
> + if (self_dominates && callee_node == callee) {
> + break;
> + }
> +
> + callees.safe_push (callee_node);
> + }
> +
> + }
> + return callees;
> +}
> +
> +
> +//XXX: Move to class symtab_node in cgraph.h
> +static ipa_ref*
> +symtab_node_iterate_address_uses (const symtab_node *n,
> + unsigned i,
> + ipa_ref *&ref)
> +{
> + n->ref_list.referring.iterate (i, &ref);
> +
> + if (ref && ref->use != IPA_REF_ADDR)
> + return NULL;
> +
> + return ref;
> +}
> +
> +//XXX: Move to class symtab_node in cgraph.h
> +static bool
> +symtab_node_address_matters_p(const symtab_node *n)
> +{
> + ipa_ref *ref = NULL;
> +
> + return (symtab_node_iterate_address_uses (n, 0, ref) != NULL);
> +}
> +
> +static bool
> +bb1_dominates_bb2 (basic_block bb1, basic_block bb2, cgraph_node *cnode)
> +{
> + // self dominance
> + if (bb1 == bb2) return true;
> +
> + push_cfun (DECL_STRUCT_FUNCTION (cnode->decl));
> +
> + /* If dominator info is not available, we need to calculate it. */
> + if (!dom_info_available_p (CDI_DOMINATORS))
> + calculate_dominance_info (CDI_DOMINATORS);
> +
> + /* Check if the read is dominated by the write. */
> + bool ret = dominated_by_p (CDI_DOMINATORS, bb2, bb1);
> +
> + /* Restore cfun. */
> + pop_cfun ();
> +
> + return ret;
> +}
> +
> +static bool
> +write_before_read_in_function (struct ipa_ref *write, struct ipa_ref *read)
> +{
> + basic_block w_bb = gimple_bb (write->stmt);
> + basic_block r_bb = gimple_bb (read->stmt);
> +
> + if (w_bb != r_bb)
> + {
> + /*
> + * The dominator framework operates on cfun.
> + * Therefore we need to set cfun accordingly.
> + */
> + symtab_node *w_node = write->referring;
> + cgraph_node *w_cnode = dyn_cast <cgraph_node *> (w_node);
> + return bb1_dominates_bb2(w_bb, r_bb, w_cnode);
> + }
> +
> + gimple_stmt_iterator gsi;
> + for (gsi = gsi_start_bb (w_bb); !gsi_end_p (gsi); gsi_next(&gsi))
> + {
> + if (gsi_stmt (gsi) == write->stmt)
> + return true;
> + if (gsi_stmt (gsi) == read->stmt)
> + return false;
> + }
> +
> + /* Neither write nor read found it BB. */
> + gcc_assert (1);
> +
> + return false;
> +}
> +
> +/*
> + * DFS over callees and return if callee is a or b.
> + */
> +static cgraph_node*
> +find_cgraph_in_callee_set (cgraph_node* n,
> + hash_set<cgraph_node*> set,
> + cgraph_node* a,
> + cgraph_node* b)
> +{
> + cgraph_edge *cs;
> + for (cs = n->callees; cs; cs = cs->next_callee)
> + {
> + cgraph_node *callee = cs->callee->function_symbol ();
> + if (dump_file)
> + fprintf (dump_file, "Child of %s: %s\n", n->dump_asm_name (), \
> + callee->dump_asm_name ());
> + if (callee == a)
> + return a;
> + if (callee == b)
> + return b;
> + if (!set.contains (callee))
> + continue;
> + return find_cgraph_in_callee_set (callee, set, a, b);
> + }
> + return NULL;
> +}
> +
> +/* Walks back along caller relations until main is found. */
> +static cgraph_node*
> +get_ancestor_main_dfs (hash_set<cgraph_node*>* visited,
> + vec<cgraph_node*>* path,
> + cgraph_node *node)
> +{
> + if (MAIN_NAME_P (DECL_NAME (node->decl)))
> + {
> + path->safe_push(node);
> + return node;
> + }
> +
> + visited->add (node);
> +
> + cgraph_edge *cs;
> + for (cs = node->callers; cs; cs = cs->next_caller)
> + {
> + cgraph_node *caller = cs->caller->function_symbol ();
> + if (!visited->contains (caller))
> + {
> + cgraph_node* main =
> + get_ancestor_main_dfs (visited, path, caller);
> + if (main)
> + {
> + path->safe_push(node);
> + return main;
> + }
> + }
> + }
> + return NULL;
> +}
> +
> +static cgraph_node*
> +get_path_from_main_to(cgraph_node *node, vec<cgraph_node*>* path)
> +{
> + hash_set<cgraph_node*> visited;
> + cgraph_node* main = get_ancestor_main_dfs (&visited, path, node);
> + visited.empty();
> + return main;
> +}
> +
> +
> +/*
> + * Verifying that a stmt s1 is dominated by a stmt s2
> + * across function borders is not trivial with the available
> + * infrastructure (dominator algorithm on bb level plus cgraph).
> + * If we rule out external calls/callbacks, then we still need
> + * to guarantee a write on each possible path to the read.
> + *
> + * The implemented solution to this problem, which is of course
> + * too strict,
> + * but also not too compute/memory intensive is as follows:
> + *
> + * - Check if write is reachable by main() by only looking into
> + * the first bb in each function on the path.
> + * - All call stmts between main() and write must not possibly
> + * reach a read. We consider indirect call statements as
> + * possible reaching read (unless we can prove opposite).
> + *
> + * The external calls/callbacks are ruled out as follows:
> + *
> + * - all possible ancestors of read must not be external visible
> + * - all possible ancestors of read must not be function pointers
> + * ???????????
> + *
> + *
> + */
> +static bool
> +write_before_read_across_function_borders (struct ipa_ref *write,
> + struct ipa_ref *read)
> +{
> + symtab_node *w_node = write->referring;
> + cgraph_node *w_cnode = dyn_cast <cgraph_node *> (w_node);
> + symtab_node *r_node = read->referring;
> + cgraph_node *r_cnode = dyn_cast <cgraph_node *> (r_node);
> + cgraph_node *main;
> +
> + /* Get main() function. */
> + vec<cgraph_node*> pw = vNULL;
> + main = get_path_from_main_to(w_cnode, &pw);
> + if (!main)
> + {
> + if (dump_file)
> + fprintf (dump_file, \
> + "main() is not ancestor of write -> skipping.\n");
> + return false;
> + }
> +
> + vec<cgraph_node*> pr = vNULL;
> + cgraph_node *main_to_read = get_path_from_main_to(r_cnode, &pr);
> + if (!main_to_read)
> + {
> + if (dump_file)
> + fprintf (dump_file, \
> + "main() is not ancestor of read -> skipping.\n");
> + return false;
> + }
> +
> + int i;
> + cgraph_node *node_in_pr;
> + FOR_EACH_VEC_ELT (pr, i, node_in_pr)
> + {
> + // I think main has to be externally visible.
> + if (node_in_pr == main) continue;
> +
> + /* Assure that all paths to read are not externally visible. */
> + if (cgraph_externally_visible_p (node_in_pr, flag_whole_program))
> + {
> + if (dump_file)
> + fprintf (dump_file, \
> + "%s is externally visible... skipping\n", \
> + node_in_pr->dump_asm_name ());
> + return false;
> + }
> +
> + /* Assure that all paths to read are not
> + * used as function pointers. */
> + if (node_in_pr->address_taken)
> + {
> + if (dump_file)
> + fprintf (dump_file, \
> + "%s might be function pointer... skipping\n", \
> + node_in_pr->dump_asm_name ());
> + return false;
> + }
> + }
> +
> + cgraph_node* caller = main;
> + cgraph_node* node_in_pw;
> + FOR_EACH_VEC_ELT (pw, i, node_in_pw)
> + {
> + gcc_assert (w_cnode != r_cnode);
> + if (node_in_pw == r_cnode && path_exists(r_cnode, w_cnode))
> + {
> + return call_before_read(write, read);
> + }
> +
> + if (node_in_pw == w_cnode && path_exists(w_cnode, r_cnode))
> + {
> + return write_before_call(write, read);
> + }
> +
> + if (node_in_pw == main)
> + {
> + continue;
> + }
> +
> + if (dump_file)
> + fprintf (dump_file, \
> + "get_nondominated_callees from %s to %s\n", \
> + caller->dump_asm_name(), \
> + node_in_pw->dump_asm_name());
> +
> + vec<cgraph_node *> non_dominated_callees = \
> + get_nondominated_callees(caller, node_in_pw);
> + cgraph_node* non_dominated_callee;
> + int j;
> + FOR_EACH_VEC_ELT(non_dominated_callees, j, non_dominated_callee)
> + {
> + if (dump_file)
> + fprintf (dump_file, "callee %d %s\n", j, \
> + non_dominated_callee->dump_asm_name());
> + if(path_exists(non_dominated_callee, r_cnode)) {
> + return false;
> + }
> + }
> +
> +
> + caller = node_in_pw;
> + }
> + return true;
> +}
> +
> +
> +static bool
> +write_before_call (struct ipa_ref *write, struct ipa_ref *read)
> +{
> + symtab_node *w_node = write->referring;
> + cgraph_node *w_cnode = dyn_cast <cgraph_node *> (w_node);
> + symtab_node *r_node = read->referring;
> + cgraph_node *r_cnode = dyn_cast <cgraph_node *> (r_node);
> +
> + gcc_assert (path_exists(w_cnode, r_cnode));
> + gcc_assert (w_cnode != r_cnode);
> +
> + basic_block w_bb = gimple_bb (write->stmt);
> + basic_block r_bb = gimple_bb (read->stmt);
> +
> + if (in_lto_p) {
> + w_cnode->get_untransformed_body ();
> + }
> +
> + function *func = DECL_STRUCT_FUNCTION (w_cnode->decl);
> + basic_block c_bb;
> + vec<struct cgraph_node*> callees = vNULL;
> + FOR_EACH_BB_FN(c_bb, func)
> + {
> + bool self_dominates = w_bb == c_bb;
> + bool w_bb_dominates_c_bb = bb1_dominates_bb2(w_bb, c_bb, w_cnode);
> + if (w_bb_dominates_c_bb && !self_dominates) continue;
> +
> + for (gimple_stmt_iterator gsi = gsi_start_bb (c_bb); \
> + !gsi_end_p (gsi); \
> + gsi_next (&gsi))
> + {
> + gimple *stmt = gsi_stmt (gsi);
> +
> + if (stmt == write->stmt) {
> + break;
> + }
> +
> + if (gimple_code (stmt) != GIMPLE_CALL) {
> + continue;
> + }
> +
> + tree callee_decl = gimple_call_fndecl (stmt);
> + cgraph_node *callee_node = cgraph_node::get (callee_decl);
> +
> + if (fndecl_built_in_p (callee_node->decl))
> + continue;
> +
> + if (dump_file)
> + fprintf (dump_file, "found callee %s\n", \
> + callee_node->dump_asm_name());
> + callees.safe_push (callee_node);
> +
> + }
> + }
> + cgraph_node* callee;
> + int i;
> + FOR_EACH_VEC_ELT(callees, i, callee)
> + {
> + if(path_exists(callee, r_cnode))
> + {
> + return false;
> + }
> + }
> +
> + return true;
> +}
> +
> +static bool
> +call_before_read (struct ipa_ref *write, struct ipa_ref *read)
> +{
> + symtab_node *w_node = write->referring;
> + cgraph_node *w_cnode = dyn_cast <cgraph_node *> (w_node);
> + symtab_node *r_node = read->referring;
> + cgraph_node *r_cnode = dyn_cast <cgraph_node *> (r_node);
> +
> + gcc_assert (path_exists(r_cnode, w_cnode));
> + gcc_assert (w_cnode != r_cnode);
> +
> + basic_block w_bb = gimple_bb (write->stmt);
> + basic_block r_bb = gimple_bb (read->stmt);
> +
> + if (in_lto_p)
> + r_cnode->get_untransformed_body ();
> +
> + function *func = DECL_STRUCT_FUNCTION (r_cnode->decl);
> + basic_block c_bb;
> + FOR_EACH_BB_FN(c_bb, func)
> + {
> + bool self_dominates = c_bb == r_bb;
> + bool call_dominates_read = bb1_dominates_bb2(c_bb, r_bb, r_cnode);
> + if (!call_dominates_read && !self_dominates) continue;
> +
> + for (gimple_stmt_iterator gsi = gsi_start_bb (c_bb); \
> + !gsi_end_p (gsi); \
> + gsi_next (&gsi))
> + {
> + gimple *stmt = gsi_stmt (gsi);
> +
> + // self dominance
> + if (stmt == read->stmt) {
> + break;
> + }
> +
> + if (gimple_code (stmt) != GIMPLE_CALL) {
> + continue;
> + }
> +
> + tree callee_decl = gimple_call_fndecl (stmt);
> + cgraph_node *callee_node = cgraph_node::get (callee_decl);
> +
> + if(path_exists(callee_node, w_cnode)) {
> + return true;
> + }
> + }
> + }
> + return false;
> +}
> +
> +static bool
> +write_before_read (struct ipa_ref *write, struct ipa_ref *read)
> +{
> + symtab_node *w_node = write->referring;
> + cgraph_node *w_cnode = dyn_cast <cgraph_node *> (w_node);
> + symtab_node *r_node = read->referring;
> + cgraph_node *r_cnode = dyn_cast <cgraph_node *> (r_node);
> +
> + if (w_cnode == r_cnode)
> + /* Within the same function. */
> + return write_before_read_in_function (write, read);
> +
> + /* Not within the same function. */
> + return write_before_read_across_function_borders (write, read);
> +}
> +
> +static bool
> +write_before_all_reads (struct ipa_ref* write,
> + const ipa_ref_vec &reads)
> +{
> + int i;
> + struct ipa_ref* read;
> +
> + FOR_EACH_VEC_ELT (reads, i, read)
> + {
> + load_function_body_of_ipa_ref (read);
> + if (!write_before_read (write, read))
> + return false;
> + }
> + return true;
> +}
> +
> +static void
> +propagate_constant_to_read (tree write_val,
> + struct ipa_ref* ref,
> + hash_set<cgraph_node*> *func)
> +{
> + gcc_assert (ref->use == IPA_REF_LOAD);
> + load_function_body_of_ipa_ref (ref);
> +
> + gimple *read_stmt = ref->stmt;
> +
> + gcc_assert (gimple_code (read_stmt) == GIMPLE_ASSIGN);
> + gcc_assert (gimple_num_ops (read_stmt) == 2);
> +
> + tree old_lhs = gimple_op (read_stmt, 0);
> + symtab_node *r_node = ref->referring;
> + cgraph_node *r_cnode = dyn_cast <cgraph_node *> (r_node);
> +
> + //if (!func->contains(r_cnode)) func->add(r_cnode);
> + cgraph_node **possible_clone = func_to_clone->get(r_cnode);
> + if (!possible_clone) {
> + const char* suffix = "test";
> + // callers has to be vNULL, otherwise, we will be
> + // analyzing clones...
> + // and we don't want that...
> + // but that means that we will need to update the callers
> + // later... in update_callgraph
> + cgraph_node *clone = r_cnode->create_version_clone_with_body(
> + vNULL,
> + NULL,
> + NULL,
> + NULL,
> + NULL,
> + suffix,
> + NULL);
> + clone->get_untransformed_body();
> + func_to_clone->put(r_cnode, clone);
> + }
> +
> + possible_clone = func_to_clone->get(r_cnode);
> + cgraph_node *clone = *possible_clone;
> +
> + // Build new stmt and replace old.
> + gimple_stmt_iterator gsi;
> + basic_block bb;
> + // Let's create a clone with body here...
> + // The clone should not have callers as
> + // to not interfere with the current
> + // analysis.
> + // The callers will be set at the end...
> +
> + push_cfun (DECL_STRUCT_FUNCTION (clone->decl));
> + function *clone_func = DECL_STRUCT_FUNCTION (clone->decl);
> + bool found = false;
> + FOR_EACH_BB_FN(bb, clone_func)
> + {
> + for (gsi = gsi_start_bb(bb); !gsi_end_p(gsi); gsi_next(&gsi))
> + {
> + gimple *stmt = gsi_stmt (gsi);
> + if (gimple_code (stmt) != GIMPLE_ASSIGN) continue;
> + tree old_val_clone = gimple_op (stmt, 1);
> + tree lhs = gimple_op (stmt, 0);
> +
> + //TODO: what happens when it is not a variable decl?
> + //This might actually be the source of imprecision
> + if (TREE_CODE(old_val_clone) != VAR_DECL) continue;
> + tree old_val = gimple_op (read_stmt, 1);
> + if (IDENTIFIER_POINTER(DECL_NAME(old_val_clone)) != \
> + IDENTIFIER_POINTER(DECL_NAME(old_val))) continue;
> +
> +
> + found = true;
> +
> + // REPLACE!!!
> + gimple_stmt_iterator gsi2 = gsi_for_stmt(stmt);
> + tree new_lhs = make_ssa_name(TREE_TYPE(lhs));
> + gimple *new_read_stmt = \
> + gimple_build_assign(new_lhs, write_val);
> + gsi_insert_before (&gsi2, new_read_stmt, GSI_SAME_STMT);
> +
> + gimple *use_stmt;
> + imm_use_iterator use_iter;
> + FOR_EACH_IMM_USE_STMT (use_stmt, use_iter, lhs)
> + {
> + use_operand_p use_p;
> + FOR_EACH_IMM_USE_ON_STMT (use_p, use_iter)
> + SET_USE (use_p, new_lhs);
> + update_stmt (use_stmt);
> + }
> + }
> +
> + if (found) break;
> + }
> + pop_cfun();
> +}
> +
> +
> +
> +static void
> +ipa_initcall_get_writes_and_reads(varpool_node *vnode,
> + ipa_ref_vec *writes,
> + ipa_ref_vec *reads)
> +{
> + int i;
> + struct ipa_ref *ref;
> +
> + if (dump_file)
> + fprintf (dump_file, "%s for variable '%s'.\n", __func__, vnode->name ());
> +
> + /* Only IPA_REF_STORE and IPA_REF_LOAD left. */
> + for (i = 0; vnode->iterate_referring (i, ref); i++)
> + {
> + if (ref->use == IPA_REF_STORE)
> + writes->safe_push (ref);
> + if (ref->use == IPA_REF_LOAD)
> + reads->safe_push (ref);
> + }
> +}
> +
> +static void
> +propagate_constant_to_reads (tree write_val,
> + const ipa_ref_vec &reads_original,
> + hash_set<cgraph_node*> *funcs)
> +{
> + /* Iterate over reads and replace them by constant. */
> + struct ipa_ref* ref;
> + int i;
> + FOR_EACH_VEC_ELT (reads_original, i, ref)
> + {
> + propagate_constant_to_read (write_val, ref, funcs);
> + }
> +}
> +
> +/*
> + * Extracts the assigned constant, iff the given statement
> + * is a constant assignment. Returns NULL_TREE otherwise.
> + */
> +static tree
> +extract_constant_from_initcall_write (struct ipa_ref *write)
> +{
> + symtab_node *f_node = write->referring;
> + cgraph_node *f_cnode = dyn_cast <cgraph_node *> (f_node);
> +
> + tree decl = f_cnode->decl;
> + if (TREE_CODE (decl) != FUNCTION_DECL)
> + {
> + if (dump_file)
> + fprintf (dump_file, "Not function decl -> skipping.\n");
> + return NULL_TREE;
> + }
> +
> + if (!f_cnode->has_gimple_body_p () && dump_file)
> + fprintf (dump_file, "Does NOT have gimple body!\n");
> + if (f_cnode->inlined_to && dump_file)
> + fprintf (dump_file, "Inlined To\n");
> +
> + if (dump_file)
> + {
> + fprintf (dump_file, "%s: for writer gimple:\n", __func__);
> + dump_vnode_ipa_ref(write);
> + }
> +
> + /* Get the write function's body. */
> + load_function_body_of_ipa_ref (write);
> +
> + gimple *stmt = write->stmt;
> +
> + /* Verify that we have an assignment. */
> + if (gimple_code (stmt) != GIMPLE_ASSIGN)
> + {
> + if (dump_file)
> + fprintf (dump_file, "Write stmt not assignment -> skipping.\n");
> + return NULL_TREE;
> + }
> +
> + /* Check if write's LHS (vnode) is not volatile. */
> + tree lhs = gimple_assign_lhs (stmt);
> + if (TREE_THIS_VOLATILE (TREE_TYPE (lhs)))
> + {
> + if (dump_file)
> + fprintf (dump_file, "Variable volatile -> skipping.\n");
> + return NULL_TREE;
> + }
> +
> + /* Check if RHS of write stmt is constant. */
> + if (!gimple_assign_is_single_const (stmt))
> + {
> + if (dump_file)
> + {
> + fprintf (dump_file, "Found non-const operands.\n");
> + }
> + return NULL_TREE;
> + }
> +
> + /* Extract the constant. */
> + tree write_val = gimple_op (stmt, 1);
> +
> + if (dump_file)
> + {
> + fprintf (dump_file, "Const op:\n");
> + dump_node (write_val, TDF_DETAILS, dump_file);
> + }
> +
> + return write_val;
> +}
> +
> +static void
> +ipa_initcall_cp_execute_for_var (varpool_node *vnode,
> + hash_set<cgraph_node*> *update_functions)
> +{
> + ipa_ref_vec writes = vNULL;
> + ipa_ref_vec reads = vNULL;
> + struct ipa_ref* write;
> + tree write_val;
> + gimple_stmt_iterator gsi;
> + bool remove_permanently;
> +
> + if (dump_file)
> + fprintf (dump_file, "%s for variable '%s'.\n", __func__, vnode->name ());
> +
> + if (dump_file)
> + {
> + dump_node (vnode->decl, TDF_DETAILS, dump_file);
> + }
> +
> + /* Variable must not be externally visible. */
> + if (vnode->externally_visible_p ())
> + {
> + if (dump_file)
> + fprintf (dump_file, \
> + "\texternally visible "\
> + "-> skipping\n");
> + return;
> + }
> +
> + /* All refs must be explicit. */
> + if (!vnode->all_refs_explicit_p ())
> + {
> + if (dump_file)
> + fprintf (dump_file,\
> + "Not explicit variable refs "\
> + "-> skipping.\n");
> + return;
> + }
> +
> + /* Check if any ref->use is IPA_REF_ALIAS. */
> + if (vnode->has_aliases_p ())
> + {
> + if (dump_file)
> + fprintf (dump_file, "Found IPA_REF_ALIAS -> skipping.\n");
> + return;
> + }
> +
> + /* Check if any ref->use is IPA_REF_ADDR. */
> + if (symtab_node_address_matters_p (vnode))
> + {
> + if (dump_file)
> + fprintf (dump_file, "Found IPA_REF_ADDR -> skipping.\n");
> + return;
> + }
> +
> + /* We don't touch arrays. */
> + if (TREE_CODE (TREE_TYPE (vnode->decl)) == ARRAY_TYPE)
> + {
> + if (dump_file)
> + fprintf (dump_file, "Variable is array -> skipping.\n");
> + return;
> + }
> +
> + /* Get all refs (must be REF_STORE or REF_LOAD). */
> + ipa_initcall_get_writes_and_reads (vnode, &writes, &reads);
> +
> + if (writes.length () > 1)
> + {
> + /* More than one writer. */
> + if (dump_file)
> + fprintf (dump_file, "More than one writer -> skipping.\n");
> + writes.release ();
> + reads.release ();
> + return;
> + }
> + else if (writes.length () < 1)
> + {
> + /* No writer. */
> + if (dump_file)
> + fprintf (dump_file, "No writer -> skipping.\n");
> + writes.release ();
> + reads.release ();
> + return;
> + }
> +
> + /*
> + * Note:
> + * Limiting ourselfs to only one write is not necessary in general,
> + * but good enough to address the typical init() case.
> + * Big advantage is, that it makes the following code much easier.
> + *
> + * TODO: I believe that if we create clones, we might get two writes
> + * Investigate
> + */
> +
> + /* Get (only) write ref. */
> + write = writes.pop ();
> +
> + /* Check if write's RHS is a constant and get it. */
> + write_val = extract_constant_from_initcall_write (write);
> + if (write_val == NULL_TREE)
> + {
> + if (dump_file)
> + fprintf (dump_file, \
> + "Write's RHS is not constant"\
> + " -> skipping.\n");
> + writes.release ();
> + reads.release ();
> + return;
> + }
> +
> + /* Assure all reads are after the write. */
> + if (!write_before_all_reads (write, reads))
> + {
> + if (dump_file)
> + fprintf (dump_file, \
> + "Write not guaranteed "\
> + "to be before read -> skipping.\n");
> + writes.release ();
> + reads.release ();
> + return;
> + }
> +
> + /* Propagate constant to reads. */
> + propagate_constant_to_reads (write_val, reads, update_functions);
> +
> + /* Finally remove the write. */
> + gsi = gsi_for_stmt (write->stmt);
> + remove_permanently = false; //XXX: fails with true???
> + //gsi_remove (&gsi, remove_permanently);
> +
> + if (dump_file)
> + fprintf (dump_file, \
> + "Eliminated variable '%s'.\n\n", vnode->name ());
> +
> + writes.release ();
> + reads.release ();
> +}
> +
> +
> +bool
> +update_callgraph(cgraph_node *const& r_cnode,
> + cgraph_node **clone_ptr,
> + void*)
> +{
> + vec<cgraph_edge*> callers = r_cnode->collect_callers();
> + cgraph_node *clone = *clone_ptr;
> + cgraph_edge *e;
> + int i;
> + profile_count count = r_cnode->count;
> +
> + FOR_EACH_VEC_ELT(callers, i, e)
> + e->redirect_callee(clone);
> +
> +/*
> + for (e = r_cnode->callees; e; e=e->next_callee)
> + e->clone(clone, e->call_stmt, e->lto_stmt_uid, count, count, true);
> +
> + for (e = r_cnode->indirect_calls; e; e=e->next_callee)
> + e->clone(clone, e->call_stmt, e->lto_stmt_uid, count, count, true);
> +
> +
> +*/
> + for (e = clone->callers; e; e=e->next_caller)
> + {
> + e->caller->get_untransformed_body();
> + function *inner_function = \
> + DECL_STRUCT_FUNCTION (e->caller->decl);
> + gimple_call_set_fndecl (e->call_stmt, clone->decl);
> + maybe_clean_eh_stmt_fn (inner_function, e->call_stmt);
> + }
> +
> + r_cnode->skip_ipa_cp = true;
> + //r_cnode->remove();
> + return true;
> +}
> +
> +static unsigned int
> +ipa_initcall_cp_execute (void)
> +{
> +
> + varpool_node *vnode;
> +
> + clone_num_suffixes1 = new hash_map<const char *, unsigned>;
> + hash_set<cgraph_node *> update_functions;
> + func_to_clone = new hash_map<cgraph_node*, cgraph_node*>;
> + FOR_EACH_VARIABLE (vnode)
> + {
> + ipa_initcall_cp_execute_for_var (vnode, &update_functions);
> + }
> +
> + func_to_clone->traverse<void*, update_callgraph>(NULL);
> +
> + delete clone_num_suffixes1;
> + delete func_to_clone;
> +
> + return 0;
> +
> +}
> +
> +namespace {
> +
> +const pass_data pass_data_ipa_initcall_cp =
> +{
> + SIMPLE_IPA_PASS, /* type */
> + "initcall_cp", /* name */
> + OPTGROUP_NONE, /* optinfo_flags */
> + TV_NONE, /* tv_id */
> + ( PROP_cfg | PROP_ssa ), /* properties_required */
> + 0, /* properties_provided */
> + 0, /* properties_destroyed */
> + 0,
> + ( TODO_update_ssa | TODO_cleanup_cfg | TODO_dump_symtab \
> + | TODO_rebuild_cgraph_edges | TODO_discard_function ),
> +};
> +
> +class pass_ipa_initcall_cp : public simple_ipa_opt_pass
> +{
> +public:
> + pass_ipa_initcall_cp (gcc::context *ctxt)
> + : simple_ipa_opt_pass (pass_data_ipa_initcall_cp, ctxt)
> + {}
> +
> + /* opt_pass methods: */
> + virtual bool gate (function *)
> + {
> + return flag_initcall_cp;
> + }
> +
> + virtual unsigned int execute (function *)
> + {
> + return ipa_initcall_cp_execute();
> + }
> +
> +}; // class pass_ipa_initcall_cp
> +
> +} // anon namespace
> +
> +simple_ipa_opt_pass *
> +make_pass_ipa_initcall_cp (gcc::context *ctxt)
> +{
> + return new pass_ipa_initcall_cp (ctxt);
> +}
> diff --git a/gcc/passes.def b/gcc/passes.def
> index 798a391..350a4fc 100644
> --- a/gcc/passes.def
> +++ b/gcc/passes.def
> @@ -146,6 +146,7 @@ along with GCC; see the file COPYING3. If not see
> NEXT_PASS (pass_ipa_profile);
> NEXT_PASS (pass_ipa_icf);
> NEXT_PASS (pass_ipa_devirt);
> + NEXT_PASS (pass_ipa_initcall_cp);
> NEXT_PASS (pass_ipa_cp);
> NEXT_PASS (pass_ipa_sra);
> NEXT_PASS (pass_ipa_cdtor_merge);
> diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h
> index a987661..9e64373 100644
> --- a/gcc/tree-pass.h
> +++ b/gcc/tree-pass.h
> @@ -498,6 +498,7 @@ extern ipa_opt_pass_d *make_pass_ipa_fn_summary
> (gcc::context *ctxt);
> extern ipa_opt_pass_d *make_pass_ipa_inline (gcc::context *ctxt);
> extern simple_ipa_opt_pass *make_pass_ipa_free_lang_data (gcc::context
> *ctxt);
> extern simple_ipa_opt_pass *make_pass_ipa_free_fn_summary (gcc::context
> *ctxt);
> +extern simple_ipa_opt_pass *make_pass_ipa_initcall_cp (gcc::context *ctxt);
> extern ipa_opt_pass_d *make_pass_ipa_cp (gcc::context *ctxt);
> extern ipa_opt_pass_d *make_pass_ipa_sra (gcc::context *ctxt);
> extern ipa_opt_pass_d *make_pass_ipa_icf (gcc::context *ctxt);
>
