-/* Callgraph handling code.
- Copyright (C) 2003 Free Software Foundation, Inc.
+/* Callgraph based intraprocedural optimizations.
+ Copyright (C) 2003, 2004 Free Software Foundation, Inc.
Contributed by Jan Hubicka
This file is part of GCC.
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
+/* This module implements main driver of compilation process as well as
+ few basic intraprocedural optimizers.
+
+ The main scope of this file is to act as an interface in between
+ tree based frontends and the backend (and middle end)
+
+ The front-end is supposed to use following functionality:
+
+ - cgraph_finalize_function
+
+ This function is called once front-end has parsed whole body of function
+ and it is certain that the function body nor the declaration will change.
+
+ (There is one exception needed for implementing GCC extern inline function.)
+
+ - cgraph_varpool_finalize_variable
+
+ This function has same behavior as the above but is used for static
+ variables.
+
+ - cgraph_finalize_compilation_unit
+
+ This function is called once compilation unit is finalized and it will
+ no longer change.
+
+ In the unit-at-a-time the call-graph construction and local function
+ analysis takes place here. Bodies of unreachable functions are released
+ to conserve memory usage.
+
+ ??? The compilation unit in this point of view should be compilation
+ unit as defined by the language - for instance C frontend allows multiple
+ compilation units to be parsed at once and it should call function each
+ time parsing is done so we save memory.
+
+ - cgraph_optimize
+
+ In this unit-at-a-time compilation the intra procedural analysis takes
+ place here. In particular the static functions whose address is never
+ taken are marked as local. Backend can then use this information to
+ modify calling conventions, do better inlining or similar optimizations.
+
+ - cgraph_assemble_pending_functions
+ - cgraph_varpool_assemble_pending_variables
+
+ In non-unit-at-a-time mode these functions can be used to force compilation
+ of functions or variables that are known to be needed at given stage
+ of compilation
+
+ - cgraph_mark_needed_node
+ - cgraph_varpool_mark_needed_node
+
+ When function or variable is referenced by some hidden way (for instance
+ via assembly code and marked by attribute "used"), the call-graph data structure
+ must be updated accordingly by this function.
+
+ - analyze_expr callback
+
+ This function is responsible for lowering tree nodes not understood by
+ generic code into understandable ones or alternatively marking
+ callgraph and varpool nodes referenced by the as needed.
+
+ ??? On the tree-ssa genericizing should take place here and we will avoid
+ need for these hooks (replacing them by genericizing hook)
+
+ - expand_function callback
+
+ This function is used to expand function and pass it into RTL back-end.
+ Front-end should not make any assumptions about when this function can be
+ called. In particular cgraph_assemble_pending_functions,
+ cgraph_varpool_assemble_pending_variables, cgraph_finalize_function,
+ cgraph_varpool_finalize_function, cgraph_optimize can cause arbitrarily
+ previously finalized functions to be expanded.
+
+ We implement two compilation modes.
+
+ - unit-at-a-time: In this mode analyzing of all functions is deferred
+ to cgraph_finalize_compilation_unit and expansion into cgraph_optimize.
+
+ In cgraph_finalize_compilation_unit the reachable functions are
+ analyzed. During analysis the call-graph edges from reachable
+ functions are constructed and their destinations are marked as
+ reachable. References to functions and variables are discovered too
+ and variables found to be needed output to the assembly file. Via
+ mark_referenced call in assemble_variable functions referenced by
+ static variables are noticed too.
+
+ The intra-procedural information is produced and it's existence
+ indicated by global_info_ready. Once this flag is set it is impossible
+ to change function from !reachable to reachable and thus
+ assemble_variable no longer call mark_referenced.
+
+ Finally the call-graph is topologically sorted and all reachable functions
+ that has not been completely inlined or are not external are output.
+
+ ??? It is possible that reference to function or variable is optimized
+ out. We can not deal with this nicely because topological order is not
+ suitable for it. For tree-ssa we may consider another pass doing
+ optimization and re-discovering reachable functions.
+
+ ??? Reorganize code so variables are output very last and only if they
+ really has been referenced by produced code, so we catch more cases
+ where reference has been optimized out.
+
+ - non-unit-at-a-time
+
+ All functions are variables are output as early as possible to conserve
+ memory consumption. This may or may not result in less memory used but
+ it is still needed for some legacy code that rely on particular ordering
+ of things output from the compiler.
+
+ Varpool data structures are not used and variables are output directly.
+
+ Functions are output early using call of
+ cgraph_assemble_pending_function from cgraph_finalize_function. The
+ decision on whether function is needed is made more conservative so
+ uninlininable static functions are needed too. During the call-graph
+ construction the edge destinations are not marked as reachable and it
+ is completely relied upn assemble_variable to mark them.
+
+ Inlining decision heuristics
+ ??? Move this to separate file after tree-ssa merge.
+
+ We separate inlining decisions from the inliner itself and store it
+ inside callgraph as so called inline plan. Reffer to cgraph.c
+ documentation about particular representation of inline plans in the
+ callgraph
+
+ The implementation of particular heuristics is separated from
+ the rest of code to make it easier to replace it with more complicated
+ implementation in the future. The rest of inlining code acts as a
+ library aimed to modify the callgraph and verify that the parameters
+ on code size growth fits.
+
+ To mark given call inline, use cgraph_mark_inline function, the
+ verification is performed by cgraph_default_inline_p and
+ cgraph_check_inline_limits.
+
+ The heuristics implements simple knapsack style algorithm ordering
+ all functions by their "profitability" (estimated by code size growth)
+ and inlining them in priority order.
+
+ cgraph_decide_inlining implements heuristics taking whole callgraph
+ into account, while cgraph_decide_inlining_incrementally considers
+ only one function at a time and is used in non-unit-at-a-time mode. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
+#include "rtl.h"
#include "tree-inline.h"
#include "langhooks.h"
#include "hashtab.h"
#include "target.h"
#include "cgraph.h"
#include "diagnostic.h"
+#include "timevar.h"
+#include "params.h"
+#include "fibheap.h"
+#include "c-common.h"
+#include "intl.h"
+#include "function.h"
+
+#define INSNS_PER_CALL 10
+
+static void cgraph_expand_all_functions (void);
+static void cgraph_mark_functions_to_output (void);
+static void cgraph_expand_function (struct cgraph_node *);
+static tree record_call_1 (tree *, int *, void *);
+static void cgraph_mark_local_functions (void);
+static bool cgraph_default_inline_p (struct cgraph_node *n);
+static void cgraph_analyze_function (struct cgraph_node *node);
+static void cgraph_decide_inlining_incrementally (struct cgraph_node *);
+
+/* Statistics we collect about inlining algorithm. */
+static int ncalls_inlined;
+static int nfunctions_inlined;
+static int initial_insns;
+static int overall_insns;
+
+/* Records tree nodes seen in cgraph_create_edges. Simply using
+ walk_tree_without_duplicates doesn't guarantee each node is visited
+ once because it gets a new htab upon each recursive call from
+ record_calls_1. */
+static htab_t visited_nodes;
+
+/* Determine if function DECL is needed. That is, visible to something
+ either outside this translation unit, something magic in the system
+ configury, or (if not doing unit-at-a-time) to something we havn't
+ seen yet. */
+
+static bool
+decide_is_function_needed (struct cgraph_node *node, tree decl)
+{
+ struct cgraph_node *origin;
+
+ /* If we decided it was needed before, but at the time we didn't have
+ the body of the function available, then it's still needed. We have
+ to go back and re-check its dependencies now. */
+ if (node->needed)
+ return true;
+
+ /* Externally visible functions must be output. The exception is
+ COMDAT functions that must be output only when they are needed. */
+ if (TREE_PUBLIC (decl) && !DECL_COMDAT (decl) && !DECL_EXTERNAL (decl))
+ return true;
+
+ /* Constructors and destructors are reachable from the runtime by
+ some mechanism. */
+ if (DECL_STATIC_CONSTRUCTOR (decl) || DECL_STATIC_DESTRUCTOR (decl))
+ return true;
+
+ /* If the user told us it is used, then it must be so. */
+ if (lookup_attribute ("used", DECL_ATTRIBUTES (decl)))
+ return true;
+
+ /* ??? If the assembler name is set by hand, it is possible to assemble
+ the name later after finalizing the function and the fact is noticed
+ in assemble_name then. This is arguably a bug. */
+ if (DECL_ASSEMBLER_NAME_SET_P (decl)
+ && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)))
+ return true;
+
+ if (flag_unit_at_a_time)
+ return false;
+
+ /* If not doing unit at a time, then we'll only defer this function
+ if its marked for inlining. Otherwise we want to emit it now. */
+
+ /* "extern inline" functions are never output locally. */
+ if (DECL_EXTERNAL (decl))
+ return false;
+ /* Nested functions of extern inline function shall not be emit unless
+ we inlined the origin. */
+ for (origin = node->origin; origin; origin = origin->origin)
+ if (DECL_EXTERNAL (origin->decl))
+ return false;
+ /* We want to emit COMDAT functions only when absolutely necessary. */
+ if (DECL_COMDAT (decl))
+ return false;
+ if (!DECL_INLINE (decl)
+ || (!node->local.disregard_inline_limits
+ /* When declared inline, defer even the uninlinable functions.
+ This allows them to be eliminated when unused. */
+ && !DECL_DECLARED_INLINE_P (decl)
+ && (!node->local.inlinable || !cgraph_default_inline_p (node))))
+ return true;
+
+ return false;
+}
-static void cgraph_expand_functions PARAMS ((void));
-static void cgraph_mark_functions_to_output PARAMS ((void));
-static void cgraph_expand_function PARAMS ((struct cgraph_node *));
-static tree record_call_1 PARAMS ((tree *, int *, void *));
-static void cgraph_mark_local_functions PARAMS ((void));
-static void cgraph_mark_functions_to_inline_once PARAMS ((void));
-static void cgraph_optimize_function PARAMS ((struct cgraph_node *));
-
-/* Analyze function once it is parsed. Set up the local information
- available - create cgraph edges for function calles via BODY. */
+/* When not doing unit-at-a-time, output all functions enqueued.
+ Return true when such a functions were found. */
-void
-cgraph_finalize_function (decl, body)
- tree decl;
- tree body ATTRIBUTE_UNUSED;
+bool
+cgraph_assemble_pending_functions (void)
{
- struct cgraph_node *node = cgraph_node (decl);
+ bool output = false;
- node->decl = decl;
+ if (flag_unit_at_a_time)
+ return false;
- node->local.can_inline_once = tree_inlinable_function_p (decl, 1);
- if (flag_inline_trees)
- node->local.inline_many = tree_inlinable_function_p (decl, 0);
- else
- node->local.inline_many = 0;
+ while (cgraph_nodes_queue)
+ {
+ struct cgraph_node *n = cgraph_nodes_queue;
- (*debug_hooks->deferred_inline_function) (decl);
-}
+ cgraph_nodes_queue = cgraph_nodes_queue->next_needed;
+ n->next_needed = NULL;
+ if (!n->global.inlined_to && !DECL_EXTERNAL (n->decl))
+ {
+ cgraph_expand_function (n);
+ output = true;
+ }
+ }
-static struct cgraph_node *queue = NULL;
+ return output;
+}
-/* Notify finalize_compilation_unit that given node is reachable
- or needed. */
+/* DECL has been parsed. Take it, queue it, compile it at the whim of the
+ logic in effect. If NESTED is true, then our caller cannot stand to have
+ the garbage collector run at the moment. We would need to either create
+ a new GC context, or just not compile right now. */
void
-cgraph_mark_needed_node (node, needed)
- struct cgraph_node *node;
- int needed;
+cgraph_finalize_function (tree decl, bool nested)
{
- if (needed)
+ struct cgraph_node *node = cgraph_node (decl);
+
+ if (node->local.finalized)
{
- if (DECL_SAVED_TREE (node->decl))
- announce_function (node->decl);
- node->needed = 1;
+ /* As an GCC extension we allow redefinition of the function. The
+ semantics when both copies of bodies differ is not well defined.
+ We replace the old body with new body so in unit at a time mode
+ we always use new body, while in normal mode we may end up with
+ old body inlined into some functions and new body expanded and
+ inlined in others.
+
+ ??? It may make more sense to use one body for inlining and other
+ body for expanding the function but this is difficult to do. */
+
+ /* If node->output is set, then this is a unit-at-a-time compilation
+ and we have already begun whole-unit analysis. This is *not*
+ testing for whether we've already emitted the function. That
+ case can be sort-of legitimately seen with real function
+ redefinition errors. I would argue that the front end should
+ never present us with such a case, but don't enforce that for now. */
+ if (node->output)
+ abort ();
+
+ /* Reset our data structures so we can analyze the function again. */
+ memset (&node->local, 0, sizeof (node->local));
+ memset (&node->global, 0, sizeof (node->global));
+ memset (&node->rtl, 0, sizeof (node->rtl));
+ node->analyzed = false;
+ node->local.redefined_extern_inline = true;
+ while (node->callees)
+ cgraph_remove_edge (node->callees);
+
+ /* We may need to re-queue the node for assembling in case
+ we already proceeded it and ignored as not needed. */
+ if (node->reachable && !flag_unit_at_a_time)
+ {
+ struct cgraph_node *n;
+
+ for (n = cgraph_nodes_queue; n; n = n->next_needed)
+ if (n == node)
+ break;
+ if (!n)
+ node->reachable = 0;
+ }
}
- if (!node->reachable)
+
+ notice_global_symbol (decl);
+ node->decl = decl;
+ node->local.finalized = true;
+
+ /* If not unit at a time, then we need to create the call graph
+ now, so that called functions can be queued and emitted now. */
+ if (!flag_unit_at_a_time)
{
- node->reachable = 1;
- if (DECL_SAVED_TREE (node->decl))
- {
- node->aux = queue;
- queue = node;
- }
+ cgraph_analyze_function (node);
+ cgraph_decide_inlining_incrementally (node);
+ }
+
+ if (decide_is_function_needed (node, decl))
+ cgraph_mark_needed_node (node);
+
+ /* If not unit at a time, go ahead and emit everything we've found
+ to be reachable at this time. */
+ if (!nested)
+ {
+ if (!cgraph_assemble_pending_functions ())
+ ggc_collect ();
}
+
+ /* If we've not yet emitted decl, tell the debug info about it. */
+ if (!TREE_ASM_WRITTEN (decl))
+ (*debug_hooks->deferred_inline_function) (decl);
+
+ /* Possibly warn about unused parameters. */
+ if (warn_unused_parameter)
+ do_warn_unused_parameter (decl);
}
/* Walk tree and record all calls. Called via walk_tree. */
static tree
-record_call_1 (tp, walk_subtrees, data)
- tree *tp;
- int *walk_subtrees;
- void *data;
-{
- /* Record dereferences to the functions. This makes the functions
- reachable unconditionally. */
- if (TREE_CODE (*tp) == ADDR_EXPR)
- {
- tree decl = TREE_OPERAND (*tp, 0);
- if (TREE_CODE (decl) == FUNCTION_DECL)
- cgraph_mark_needed_node (cgraph_node (decl), 1);
- }
- else if (TREE_CODE (*tp) == CALL_EXPR)
- {
- /* We cannot use get_callee_fndecl here because it actually tries
- too hard to get the function declaration, looking for indirect
- references and stripping NOPS. As a result, get_callee_fndecl
- finds calls that shouldn't be in the call graph. */
-
- tree decl = TREE_OPERAND (*tp, 0);
- if (TREE_CODE (decl) == ADDR_EXPR)
- decl = TREE_OPERAND (decl, 0);
- if (TREE_CODE (decl) == FUNCTION_DECL)
+record_call_1 (tree *tp, int *walk_subtrees, void *data)
+{
+ tree t = *tp;
+
+ switch (TREE_CODE (t))
+ {
+ case VAR_DECL:
+ /* ??? Really, we should mark this decl as *potentially* referenced
+ by this function and re-examine whether the decl is actually used
+ after rtl has been generated. */
+ if (TREE_STATIC (t))
+ {
+ cgraph_varpool_mark_needed_node (cgraph_varpool_node (t));
+ if (lang_hooks.callgraph.analyze_expr)
+ return lang_hooks.callgraph.analyze_expr (tp, walk_subtrees,
+ data);
+ }
+ break;
+
+ case ADDR_EXPR:
+ if (flag_unit_at_a_time)
+ {
+ /* Record dereferences to the functions. This makes the
+ functions reachable unconditionally. */
+ tree decl = TREE_OPERAND (*tp, 0);
+ if (TREE_CODE (decl) == FUNCTION_DECL)
+ cgraph_mark_needed_node (cgraph_node (decl));
+ }
+ break;
+
+ case CALL_EXPR:
+ {
+ tree decl = get_callee_fndecl (*tp);
+ if (decl && TREE_CODE (decl) == FUNCTION_DECL)
+ {
+ cgraph_create_edge (data, cgraph_node (decl), *tp);
+
+ /* When we see a function call, we don't want to look at the
+ function reference in the ADDR_EXPR that is hanging from
+ the CALL_EXPR we're examining here, because we would
+ conclude incorrectly that the function's address could be
+ taken by something that is not a function call. So only
+ walk the function parameter list, skip the other subtrees. */
+
+ walk_tree (&TREE_OPERAND (*tp, 1), record_call_1, data,
+ visited_nodes);
+ *walk_subtrees = 0;
+ }
+ break;
+ }
+
+ default:
+ /* Save some cycles by not walking types and declaration as we
+ won't find anything useful there anyway. */
+ if (DECL_P (*tp) || TYPE_P (*tp))
{
- if (DECL_BUILT_IN (decl))
- return NULL;
- cgraph_record_call (data, decl);
-
- /* When we see a function call, we don't want to look at the
- function reference in the ADDR_EXPR that is hanging from
- the CALL_EXPR we're examining here, because we would
- conclude incorrectly that the function's address could be
- taken by something that is not a function call. So only
- walk the function parameter list, skip the other subtrees. */
-
- walk_tree (&TREE_OPERAND (*tp, 1), record_call_1, data, NULL);
*walk_subtrees = 0;
+ break;
}
+
+ if ((unsigned int) TREE_CODE (t) >= LAST_AND_UNUSED_TREE_CODE)
+ return lang_hooks.callgraph.analyze_expr (tp, walk_subtrees, data);
+ break;
}
+
return NULL;
}
-/* Create cgraph edges for function calls inside BODY from DECL. */
+/* Create cgraph edges for function calls inside BODY from NODE. */
void
-cgraph_create_edges (decl, body)
- tree decl;
- tree body;
+cgraph_create_edges (struct cgraph_node *node, tree body)
{
/* The nodes we're interested in are never shared, so walk
the tree ignoring duplicates. */
- walk_tree_without_duplicates (&body, record_call_1, decl);
+ visited_nodes = htab_create (37, htab_hash_pointer,
+ htab_eq_pointer, NULL);
+ walk_tree (&body, record_call_1, node, visited_nodes);
+ htab_delete (visited_nodes);
+ visited_nodes = NULL;
+}
+
+static bool error_found;
+
+/* Callbrack of verify_cgraph_node. Check that all call_exprs have cgraph
+ nodes. */
+
+static tree
+verify_cgraph_node_1 (tree *tp, int *walk_subtrees, void *data)
+{
+ tree t = *tp;
+ tree decl;
+
+ if (TREE_CODE (t) == CALL_EXPR && (decl = get_callee_fndecl (t)))
+ {
+ struct cgraph_edge *e = cgraph_edge (data, t);
+ if (e)
+ {
+ if (e->aux)
+ {
+ error ("Shared call_expr:");
+ debug_tree (t);
+ error_found = true;
+ }
+ if (e->callee->decl != cgraph_node (decl)->decl)
+ {
+ error ("Edge points to wrong declaration:");
+ debug_tree (e->callee->decl);
+ fprintf (stderr," Instead of:");
+ debug_tree (decl);
+ }
+ e->aux = (void *)1;
+ }
+ else
+ {
+ error ("Missing callgraph edge for call expr:");
+ debug_tree (t);
+ error_found = true;
+ }
+ }
+
+ /* Save some cycles by not walking types and declaration as we
+ won't find anything useful there anyway. */
+ if (DECL_P (*tp) || TYPE_P (*tp))
+ *walk_subtrees = 0;
+
+ return NULL_TREE;
+}
+
+/* Verify cgraph nodes of given cgraph node. */
+void
+verify_cgraph_node (struct cgraph_node *node)
+{
+ struct cgraph_edge *e;
+ struct cgraph_node *main_clone;
+
+ timevar_push (TV_CGRAPH_VERIFY);
+ error_found = false;
+ for (e = node->callees; e; e = e->next_callee)
+ if (e->aux)
+ {
+ error ("Aux field set for edge %s->%s",
+ cgraph_node_name (e->caller), cgraph_node_name (e->callee));
+ error_found = true;
+ }
+ for (e = node->callers; e; e = e->next_caller)
+ {
+ if (!e->inline_failed)
+ {
+ if (node->global.inlined_to
+ != (e->caller->global.inlined_to
+ ? e->caller->global.inlined_to : e->caller))
+ {
+ error ("Inlined_to pointer is wrong");
+ error_found = true;
+ }
+ if (node->callers->next_caller)
+ {
+ error ("Multiple inline callers");
+ error_found = true;
+ }
+ }
+ else
+ if (node->global.inlined_to)
+ {
+ error ("Inlined_to pointer set for noninline callers");
+ error_found = true;
+ }
+ }
+ if (!node->callers && node->global.inlined_to)
+ {
+ error ("Inlined_to pointer is set but no predecesors found");
+ error_found = true;
+ }
+ if (node->global.inlined_to == node)
+ {
+ error ("Inlined_to pointer reffers to itself");
+ error_found = true;
+ }
+
+ for (main_clone = cgraph_node (node->decl); main_clone;
+ main_clone = main_clone->next_clone)
+ if (main_clone == node)
+ break;
+ if (!node)
+ {
+ error ("Node not found in DECL_ASSEMBLER_NAME hash");
+ error_found = true;
+ }
+
+ if (node->analyzed
+ && DECL_SAVED_TREE (node->decl) && !TREE_ASM_WRITTEN (node->decl)
+ && (!DECL_EXTERNAL (node->decl) || node->global.inlined_to))
+ {
+ walk_tree_without_duplicates (&DECL_SAVED_TREE (node->decl),
+ verify_cgraph_node_1, node);
+ for (e = node->callees; e; e = e->next_callee)
+ {
+ if (!e->aux)
+ {
+ error ("Edge %s->%s has no corresponding call_expr",
+ cgraph_node_name (e->caller),
+ cgraph_node_name (e->callee));
+ error_found = true;
+ }
+ e->aux = 0;
+ }
+ }
+ if (error_found)
+ {
+ dump_cgraph_node (stderr, node);
+ internal_error ("verify_cgraph_node failed.");
+ }
+ timevar_pop (TV_CGRAPH_VERIFY);
+}
+
+/* Verify whole cgraph structure. */
+void
+verify_cgraph (void)
+{
+ struct cgraph_node *node;
+
+ for (node = cgraph_nodes; node; node = node->next)
+ verify_cgraph_node (node);
+}
+
+/* Analyze the function scheduled to be output. */
+static void
+cgraph_analyze_function (struct cgraph_node *node)
+{
+ tree decl = node->decl;
+ struct cgraph_edge *e;
+
+ current_function_decl = decl;
+
+ /* First kill forward declaration so reverse inlining works properly. */
+ cgraph_create_edges (node, DECL_SAVED_TREE (decl));
+
+ node->local.inlinable = tree_inlinable_function_p (decl);
+ node->local.self_insns = estimate_num_insns (DECL_SAVED_TREE (decl));
+ if (node->local.inlinable)
+ node->local.disregard_inline_limits
+ = lang_hooks.tree_inlining.disregard_inline_limits (decl);
+ for (e = node->callers; e; e = e->next_caller)
+ {
+ if (node->local.redefined_extern_inline)
+ e->inline_failed = N_("redefined extern inline functions are not "
+ "considered for inlining");
+ else if (!node->local.inlinable)
+ e->inline_failed = N_("function not inlinable");
+ else
+ e->inline_failed = N_("function not considered for inlining");
+ }
+ if (flag_really_no_inline && !node->local.disregard_inline_limits)
+ node->local.inlinable = 0;
+ /* Inlining characteristics are maintained by the cgraph_mark_inline. */
+ node->global.insns = node->local.self_insns;
+
+ node->analyzed = true;
+ current_function_decl = NULL;
}
/* Analyze the whole compilation unit once it is parsed completely. */
void
-cgraph_finalize_compilation_unit ()
+cgraph_finalize_compilation_unit (void)
{
struct cgraph_node *node;
- struct cgraph_edge *edge;
- /* Collect entry points to the unit. */
+ if (!flag_unit_at_a_time)
+ {
+ cgraph_assemble_pending_functions ();
+ return;
+ }
+ cgraph_varpool_assemble_pending_decls ();
if (!quiet_flag)
- fprintf (stderr, "\n\nUnit entry points:");
+ fprintf (stderr, "\nAnalyzing compilation unit\n");
- for (node = cgraph_nodes; node; node = node->next)
+ timevar_push (TV_CGRAPH);
+ if (cgraph_dump_file)
{
- tree decl = node->decl;
-
- if (!DECL_SAVED_TREE (decl))
- continue;
- if ((TREE_PUBLIC (decl) && !DECL_COMDAT (decl) && !DECL_EXTERNAL (decl))
- || (DECL_ASSEMBLER_NAME_SET_P (decl)
- && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))))
- {
- /* This function can be called from outside this compliation
- unit, so it most definitely is needed. */
- cgraph_mark_needed_node (node, 1);
- }
+ fprintf (cgraph_dump_file, "Initial entry points:");
+ for (node = cgraph_nodes; node; node = node->next)
+ if (node->needed && DECL_SAVED_TREE (node->decl))
+ fprintf (cgraph_dump_file, " %s", cgraph_node_name (node));
+ fprintf (cgraph_dump_file, "\n");
}
/* Propagate reachability flag and lower representation of all reachable
functions. In the future, lowering will introduce new functions and
new entry points on the way (by template instantiation and virtual
method table generation for instance). */
- while (queue)
+ while (cgraph_nodes_queue)
{
- tree decl = queue->decl;
+ struct cgraph_edge *edge;
+ tree decl = cgraph_nodes_queue->decl;
+
+ node = cgraph_nodes_queue;
+ cgraph_nodes_queue = cgraph_nodes_queue->next_needed;
+ node->next_needed = NULL;
+
+ /* ??? It is possible to create extern inline function and later using
+ weak alas attribute to kill its body. See
+ gcc.c-torture/compile/20011119-1.c */
+ if (!DECL_SAVED_TREE (decl))
+ continue;
- node = queue;
- queue = queue->aux;
- if (node->lowered || !node->reachable || !DECL_SAVED_TREE (decl))
+ if (node->analyzed || !node->reachable || !DECL_SAVED_TREE (decl))
abort ();
- /* At the moment frontend automatically emits all nested functions. */
- if (node->nested)
- {
- struct cgraph_node *node2;
+ cgraph_analyze_function (node);
- for (node2 = node->nested; node2; node2 = node2->next_nested)
- if (!node2->reachable)
- cgraph_mark_needed_node (node2, 0);
- }
+ for (edge = node->callees; edge; edge = edge->next_callee)
+ if (!edge->callee->reachable)
+ cgraph_mark_reachable_node (edge->callee);
- if (lang_hooks.callgraph.lower_function)
- (*lang_hooks.callgraph.lower_function) (decl);
+ cgraph_varpool_assemble_pending_decls ();
+ }
- /* First kill forward declaration so reverse inling works properly. */
- cgraph_create_edges (decl, DECL_SAVED_TREE (decl));
+ /* Collect entry points to the unit. */
- for (edge = node->callees; edge; edge = edge->next_callee)
- {
- if (!edge->callee->reachable)
- cgraph_mark_needed_node (edge->callee, 0);
- }
- node->lowered = true;
+ if (cgraph_dump_file)
+ {
+ fprintf (cgraph_dump_file, "Unit entry points:");
+ for (node = cgraph_nodes; node; node = node->next)
+ if (node->needed && DECL_SAVED_TREE (node->decl))
+ fprintf (cgraph_dump_file, " %s", cgraph_node_name (node));
+ fprintf (cgraph_dump_file, "\n\nInitial ");
+ dump_cgraph (cgraph_dump_file);
}
- if (!quiet_flag)
- fprintf (stderr, "\n\nReclaiming functions:");
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file, "\nReclaiming functions:");
for (node = cgraph_nodes; node; node = node->next)
{
if (!node->reachable && DECL_SAVED_TREE (decl))
{
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file, " %s", cgraph_node_name (node));
cgraph_remove_node (node);
- announce_function (decl);
}
+ else
+ node->next_needed = NULL;
+ }
+ if (cgraph_dump_file)
+ {
+ fprintf (cgraph_dump_file, "\n\nReclaimed ");
+ dump_cgraph (cgraph_dump_file);
}
ggc_collect ();
+ timevar_pop (TV_CGRAPH);
}
-
/* Figure out what functions we want to assemble. */
static void
-cgraph_mark_functions_to_output ()
+cgraph_mark_functions_to_output (void)
{
struct cgraph_node *node;
for (node = cgraph_nodes; node; node = node->next)
{
tree decl = node->decl;
+ struct cgraph_edge *e;
+ if (node->output)
+ abort ();
+
+ for (e = node->callers; e; e = e->next_caller)
+ if (e->inline_failed)
+ break;
/* We need to output all local functions that are used and not
always inlined, as well as those that are reachable from
outside the current compilation unit. */
if (DECL_SAVED_TREE (decl)
+ && !node->global.inlined_to
&& (node->needed
- || (!node->local.inline_many && !node->global.inline_once
- && node->reachable)
- || TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)))
- && !TREE_ASM_WRITTEN (decl) && !node->origin
+ || (e && node->reachable))
+ && !TREE_ASM_WRITTEN (decl)
&& !DECL_EXTERNAL (decl))
node->output = 1;
- }
-}
-
-/* Optimize the function before expansion. */
-
-static void
-cgraph_optimize_function (node)
- struct cgraph_node *node;
-{
- tree decl = node->decl;
-
- if (flag_inline_trees)
- optimize_inline_calls (decl);
- if (node->nested)
- {
- for (node = node->nested; node; node = node->next_nested)
- cgraph_optimize_function (node);
+ /* We should've reclaimed all functions that are not needed. */
+ else if (!node->global.inlined_to && DECL_SAVED_TREE (decl)
+ && !DECL_EXTERNAL (decl))
+ {
+ dump_cgraph_node (stderr, node);
+ abort ();
+ }
}
}
/* Expand function specified by NODE. */
static void
-cgraph_expand_function (node)
- struct cgraph_node *node;
+cgraph_expand_function (struct cgraph_node *node)
{
tree decl = node->decl;
- announce_function (decl);
+ /* We ought to not compile any inline clones. */
+ if (node->global.inlined_to)
+ abort ();
- cgraph_optimize_function (node);
+ if (flag_unit_at_a_time)
+ announce_function (decl);
- /* Generate RTL for the body of DECL. Nested functions are expanded
- via lang_expand_decl_stmt. */
- (*lang_hooks.callgraph.expand_function) (decl);
+ /* Generate RTL for the body of DECL. */
+ lang_hooks.callgraph.expand_function (decl);
- /* When we decided to inline the function once, we never ever should
- need to output it separately. */
- if (node->global.inline_once)
+ /* Make sure that BE didn't give up on compiling. */
+ /* ??? Can happen with nested function of extern inline. */
+ if (!TREE_ASM_WRITTEN (node->decl))
abort ();
- if (!node->local.inline_many
- || !node->callers)
- DECL_SAVED_TREE (decl) = NULL;
+
current_function_decl = NULL;
+ if (DECL_SAVED_TREE (node->decl)
+ && !cgraph_preserve_function_body_p (node->decl))
+ {
+ DECL_SAVED_TREE (node->decl) = NULL;
+ DECL_STRUCT_FUNCTION (node->decl) = NULL;
+ DECL_INITIAL (node->decl) = error_mark_node;
+ }
}
+/* Fill array order with all nodes with output flag set in the reverse
+ topological order. */
-/* Expand all functions that must be output.
-
- Attempt to topologically sort the nodes so function is output when
- all called functions are already assembled to allow data to be
- propagated accross the callgraph. Use a stack to get smaller distance
- between a function and it's callees (later we may choose to use a more
- sophisticated algorithm for function reordering; we will likely want
- to use subsections to make the output functions appear in top-down
- order. */
-
-static void
-cgraph_expand_functions ()
+static int
+cgraph_postorder (struct cgraph_node **order)
{
struct cgraph_node *node, *node2;
- struct cgraph_node **stack =
- xcalloc (sizeof (struct cgraph_node *), cgraph_n_nodes);
- struct cgraph_node **order =
- xcalloc (sizeof (struct cgraph_node *), cgraph_n_nodes);
int stack_size = 0;
int order_pos = 0;
struct cgraph_edge *edge, last;
- int i;
- cgraph_mark_functions_to_output ();
+ struct cgraph_node **stack =
+ xcalloc (cgraph_n_nodes, sizeof (struct cgraph_node *));
/* We have to deal with cycles nicely, so use a depth first traversal
output algorithm. Ignore the fact that some functions won't need
for (node = cgraph_nodes; node; node = node->next)
node->aux = NULL;
for (node = cgraph_nodes; node; node = node->next)
- if (node->output && !node->aux)
+ if (!node->aux)
{
node2 = node;
if (!node->callers)
}
}
}
- for (i = order_pos - 1; i >= 0; i--)
+ free (stack);
+ return order_pos;
+}
+
+/* Perform reachability analysis and reclaim all unreachable nodes.
+ This function also remove unneeded bodies of extern inline functions
+ and thus needs to be done only after inlining decisions has been made. */
+static bool
+cgraph_remove_unreachable_nodes (void)
+{
+ struct cgraph_node *first = (void *) 1;
+ struct cgraph_node *node;
+ bool changed = false;
+ int insns = 0;
+
+#ifdef ENABLE_CHECKING
+ verify_cgraph ();
+#endif
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file, "\nReclaiming functions:");
+#ifdef ENABLE_CHECKING
+ for (node = cgraph_nodes; node; node = node->next)
+ if (node->aux)
+ abort ();
+#endif
+ for (node = cgraph_nodes; node; node = node->next)
+ if (node->needed && !node->global.inlined_to
+ && (!DECL_EXTERNAL (node->decl) || !node->analyzed))
+ {
+ node->aux = first;
+ first = node;
+ }
+ else if (node->aux)
+ abort ();
+
+ /* Perform reachability analysis. As a special case do not consider
+ extern inline functions not inlined as live because we won't output
+ them at all. */
+ while (first != (void *) 1)
{
- node = order[i];
- if (node->output)
+ struct cgraph_edge *e;
+ node = first;
+ first = first->aux;
+
+ for (e = node->callees; e; e = e->next_callee)
+ if (!e->callee->aux
+ && node->analyzed
+ && (!e->inline_failed || !e->callee->analyzed
+ || !DECL_EXTERNAL (e->callee->decl)))
+ {
+ e->callee->aux = first;
+ first = e->callee;
+ }
+ }
+
+ /* Remove unreachable nodes. Extern inline functions need special care;
+ Unreachable extern inline functions shall be removed.
+ Reachable extern inline functions we never inlined shall get their bodies
+ eliminated.
+ Reachable extern inline functions we sometimes inlined will be turned into
+ unanalyzed nodes so they look like for true extern functions to the rest
+ of code. Body of such functions is released via remove_node once the
+ inline clones are eliminated. */
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ if (!node->aux)
{
- if (!node->reachable)
- abort ();
- node->output = 0;
- cgraph_expand_function (node);
+ int local_insns;
+ tree decl = node->decl;
+
+ node->global.inlined_to = NULL;
+ if (DECL_STRUCT_FUNCTION (decl))
+ local_insns = node->local.self_insns;
+ else
+ local_insns = 0;
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file, " %s", cgraph_node_name (node));
+ if (!node->analyzed || !DECL_EXTERNAL (node->decl))
+ cgraph_remove_node (node);
+ else
+ {
+ struct cgraph_edge *e;
+
+ for (e = node->callers; e; e = e->next_caller)
+ if (e->caller->aux)
+ break;
+ if (e || node->needed)
+ {
+ struct cgraph_node *clone;
+
+ for (clone = node->next_clone; clone;
+ clone = clone->next_clone)
+ if (clone->aux)
+ break;
+ if (!clone)
+ {
+ DECL_SAVED_TREE (node->decl) = NULL;
+ DECL_STRUCT_FUNCTION (node->decl) = NULL;
+ DECL_INITIAL (node->decl) = error_mark_node;
+ }
+ while (node->callees)
+ cgraph_remove_edge (node->callees);
+ node->analyzed = false;
+ }
+ else
+ cgraph_remove_node (node);
+ }
+ if (!DECL_SAVED_TREE (decl))
+ insns += local_insns;
+ changed = true;
}
}
- free (stack);
- free (order);
+ for (node = cgraph_nodes; node; node = node->next)
+ node->aux = NULL;
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file, "\nReclaimed %i insns", insns);
+ return changed;
}
-/* Mark all local functions.
- We can not use node->needed directly as it is modified during
- execution of cgraph_optimize. */
+/* Estimate size of the function after inlining WHAT into TO. */
+
+static int
+cgraph_estimate_size_after_inlining (int times, struct cgraph_node *to,
+ struct cgraph_node *what)
+{
+ return (what->global.insns - INSNS_PER_CALL) * times + to->global.insns;
+}
+
+/* Estimate the growth caused by inlining NODE into all callees. */
+
+static int
+cgraph_estimate_growth (struct cgraph_node *node)
+{
+ int growth = 0;
+ struct cgraph_edge *e;
+
+ for (e = node->callers; e; e = e->next_caller)
+ if (e->inline_failed)
+ growth += (cgraph_estimate_size_after_inlining (1, e->caller, node)
+ - e->caller->global.insns);
+
+ /* ??? Wrong for self recursive functions or cases where we decide to not
+ inline for different reasons, but it is not big deal as in that case
+ we will keep the body around, but we will also avoid some inlining. */
+ if (!node->needed && !DECL_EXTERNAL (node->decl))
+ growth -= node->global.insns;
+
+ return growth;
+}
+
+/* E is expected to be an edge being inlined. Clone destination node of
+ the edge and redirect it to the new clone.
+ DUPLICATE is used for bookkeeping on whether we are actually creating new
+ clones or re-using node originally representing out-of-line function call.
+ */
+void
+cgraph_clone_inlined_nodes (struct cgraph_edge *e, bool duplicate)
+{
+ struct cgraph_node *n;
+
+ /* We may eliminate the need for out-of-line copy to be output. In that
+ case just go ahead and re-use it. */
+ if (!e->callee->callers->next_caller
+ && (!e->callee->needed || DECL_EXTERNAL (e->callee->decl))
+ && duplicate
+ && flag_unit_at_a_time)
+ {
+ if (e->callee->global.inlined_to)
+ abort ();
+ if (!DECL_EXTERNAL (e->callee->decl))
+ overall_insns -= e->callee->global.insns, nfunctions_inlined++;
+ duplicate = 0;
+ }
+ else if (duplicate)
+ {
+ n = cgraph_clone_node (e->callee);
+ cgraph_redirect_edge_callee (e, n);
+ }
+
+ if (e->caller->global.inlined_to)
+ e->callee->global.inlined_to = e->caller->global.inlined_to;
+ else
+ e->callee->global.inlined_to = e->caller;
+
+ /* Recursively clone all bodies. */
+ for (e = e->callee->callees; e; e = e->next_callee)
+ if (!e->inline_failed)
+ cgraph_clone_inlined_nodes (e, duplicate);
+}
+
+/* Mark edge E as inlined and update callgraph accordingly. */
+
+void
+cgraph_mark_inline_edge (struct cgraph_edge *e)
+{
+ int old_insns = 0, new_insns = 0;
+ struct cgraph_node *to = NULL, *what;
+
+ if (!e->inline_failed)
+ abort ();
+ e->inline_failed = NULL;
+
+ if (!e->callee->global.inlined && flag_unit_at_a_time)
+ DECL_POSSIBLY_INLINED (e->callee->decl) = true;
+ e->callee->global.inlined = true;
+
+ cgraph_clone_inlined_nodes (e, true);
+
+ what = e->callee;
+
+ /* Now update size of caller and all functions caller is inlined into. */
+ for (;e && !e->inline_failed; e = e->caller->callers)
+ {
+ old_insns = e->caller->global.insns;
+ new_insns = cgraph_estimate_size_after_inlining (1, e->caller,
+ what);
+ if (new_insns < 0)
+ abort ();
+ to = e->caller;
+ to->global.insns = new_insns;
+ }
+ if (what->global.inlined_to != to)
+ abort ();
+ overall_insns += new_insns - old_insns;
+ ncalls_inlined++;
+}
+
+/* Mark all calls of EDGE->CALLEE inlined into EDGE->CALLER.
+ Return following unredirected edge in the list of callers
+ of EDGE->CALLEE */
+
+static struct cgraph_edge *
+cgraph_mark_inline (struct cgraph_edge *edge)
+{
+ struct cgraph_node *to = edge->caller;
+ struct cgraph_node *what = edge->callee;
+ struct cgraph_edge *e, *next;
+ int times = 0;
+
+ /* Look for all calls, mark them inline and clone recursively
+ all inlined functions. */
+ for (e = what->callers; e; e = next)
+ {
+ next = e->next_caller;
+ if (e->caller == to && e->inline_failed)
+ {
+ cgraph_mark_inline_edge (e);
+ if (e == edge)
+ edge = next;
+ times ++;
+ }
+ }
+ if (!times)
+ abort ();
+ return edge;
+}
+
+/* Return false when inlining WHAT into TO is not good idea
+ as it would cause too large growth of function bodies. */
+
+static bool
+cgraph_check_inline_limits (struct cgraph_node *to, struct cgraph_node *what,
+ const char **reason)
+{
+ int times = 0;
+ struct cgraph_edge *e;
+ int newsize;
+ int limit;
+
+ if (to->global.inlined_to)
+ to = to->global.inlined_to;
+
+ for (e = to->callees; e; e = e->next_callee)
+ if (e->callee == what)
+ times++;
+
+ /* When inlining large function body called once into small function,
+ take the inlined function as base for limiting the growth. */
+ if (to->local.self_insns > what->local.self_insns)
+ limit = to->local.self_insns;
+ else
+ limit = what->local.self_insns;
+
+ limit += limit * PARAM_VALUE (PARAM_LARGE_FUNCTION_GROWTH) / 100;
+
+ newsize = cgraph_estimate_size_after_inlining (times, to, what);
+ if (newsize > PARAM_VALUE (PARAM_LARGE_FUNCTION_INSNS)
+ && newsize > limit)
+ {
+ if (reason)
+ *reason = N_("--param large-function-growth limit reached");
+ return false;
+ }
+ return true;
+}
+
+/* Return true when function N is small enough to be inlined. */
+
+static bool
+cgraph_default_inline_p (struct cgraph_node *n)
+{
+ if (!DECL_INLINE (n->decl) || !DECL_SAVED_TREE (n->decl))
+ return false;
+ if (DECL_DECLARED_INLINE_P (n->decl))
+ return n->global.insns < MAX_INLINE_INSNS_SINGLE;
+ else
+ return n->global.insns < MAX_INLINE_INSNS_AUTO;
+}
+
+/* Return true when inlining WHAT would create recursive inlining.
+ We call recursive inlining all cases where same function appears more than
+ once in the single recursion nest path in the inline graph. */
+
+static bool
+cgraph_recursive_inlining_p (struct cgraph_node *to,
+ struct cgraph_node *what,
+ const char **reason)
+{
+ bool recursive;
+ if (to->global.inlined_to)
+ recursive = what->decl == to->global.inlined_to->decl;
+ else
+ recursive = what->decl == to->decl;
+ /* Marking recursive function inline has sane semantic and thus we should
+ not warn on it. */
+ if (recursive && reason)
+ *reason = (what->local.disregard_inline_limits
+ ? N_("recursive inlining") : "");
+ return recursive;
+}
+
+/* Recompute heap nodes for each of callees. */
+static void
+update_callee_keys (fibheap_t heap, struct fibnode **heap_node,
+ struct cgraph_node *node)
+{
+ struct cgraph_edge *e;
+
+ for (e = node->callees; e; e = e->next_callee)
+ if (e->inline_failed && heap_node[e->callee->uid])
+ fibheap_replace_key (heap, heap_node[e->callee->uid],
+ cgraph_estimate_growth (e->callee));
+ else if (!e->inline_failed)
+ update_callee_keys (heap, heap_node, e->callee);
+}
+
+/* Enqueue all recursive calls from NODE into queue linked via aux pointers
+ in between FIRST and LAST. WHERE is used for bookkeeping while looking
+ int calls inlined within NODE. */
+static void
+lookup_recursive_calls (struct cgraph_node *node, struct cgraph_node *where,
+ struct cgraph_edge **first, struct cgraph_edge **last)
+{
+ struct cgraph_edge *e;
+ for (e = where->callees; e; e = e->next_callee)
+ if (e->callee == node)
+ {
+ if (!*first)
+ *first = e;
+ else
+ (*last)->aux = e;
+ *last = e;
+ }
+ for (e = where->callees; e; e = e->next_callee)
+ if (!e->inline_failed)
+ lookup_recursive_calls (node, e->callee, first, last);
+}
+
+/* Decide on recursive inlining: in the case function has recursive calls,
+ inline until body size reaches given argument. */
+static void
+cgraph_decide_recursive_inlining (struct cgraph_node *node)
+{
+ int limit = PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO);
+ int max_depth = PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO);
+ struct cgraph_edge *first_call = NULL, *last_call = NULL;
+ struct cgraph_edge *last_in_current_depth;
+ struct cgraph_edge *e;
+ struct cgraph_node *master_clone;
+ int depth = 0;
+ int n = 0;
+
+ if (DECL_DECLARED_INLINE_P (node->decl))
+ {
+ limit = PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE);
+ max_depth = PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH);
+ }
+
+ /* Make sure that function is small enought to be considered for inlining. */
+ if (!max_depth
+ || cgraph_estimate_size_after_inlining (1, node, node) >= limit)
+ return;
+ lookup_recursive_calls (node, node, &first_call, &last_call);
+ if (!first_call)
+ return;
+
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file,
+ "\nPerforming recursive inlining on %s\n",
+ cgraph_node_name (node));
+
+ /* We need original clone to copy around. */
+ master_clone = cgraph_clone_node (node);
+ master_clone->needed = true;
+ for (e = master_clone->callees; e; e = e->next_callee)
+ if (!e->inline_failed)
+ cgraph_clone_inlined_nodes (e, true);
+
+ /* Do the inlining and update list of recursive call during process. */
+ last_in_current_depth = last_call;
+ while (first_call
+ && cgraph_estimate_size_after_inlining (1, node, master_clone) <= limit)
+ {
+ struct cgraph_edge *curr = first_call;
+
+ first_call = first_call->aux;
+ curr->aux = NULL;
+
+ cgraph_redirect_edge_callee (curr, master_clone);
+ cgraph_mark_inline_edge (curr);
+ lookup_recursive_calls (node, curr->callee, &first_call, &last_call);
+
+ if (last_in_current_depth
+ && ++depth >= max_depth)
+ break;
+ n++;
+ }
+
+ /* Cleanup queue pointers. */
+ while (first_call)
+ {
+ struct cgraph_edge *next = first_call->aux;
+ first_call->aux = NULL;
+ first_call = next;
+ }
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file,
+ "\n Inlined %i times, body grown from %i to %i insns\n", n,
+ master_clone->global.insns, node->global.insns);
+
+ /* Remove master clone we used for inlining. We rely that clones inlined
+ into master clone gets queued just before master clone so we don't
+ need recursion. */
+ for (node = cgraph_nodes; node != master_clone;
+ node = node->next)
+ if (node->global.inlined_to == master_clone)
+ cgraph_remove_node (node);
+ cgraph_remove_node (master_clone);
+}
+
+/* Set inline_failed for all callers of given function to REASON. */
static void
-cgraph_mark_local_functions ()
+cgraph_set_inline_failed (struct cgraph_node *node, const char *reason)
+{
+ struct cgraph_edge *e;
+
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file, "Inlining failed: %s\n", reason);
+ for (e = node->callers; e; e = e->next_caller)
+ if (e->inline_failed)
+ e->inline_failed = reason;
+}
+
+/* We use greedy algorithm for inlining of small functions:
+ All inline candidates are put into prioritized heap based on estimated
+ growth of the overall number of instructions and then update the estimates.
+
+ INLINED and INLINED_CALEES are just pointers to arrays large enough
+ to be passed to cgraph_inlined_into and cgraph_inlined_callees. */
+
+static void
+cgraph_decide_inlining_of_small_functions (void)
{
struct cgraph_node *node;
+ fibheap_t heap = fibheap_new ();
+ struct fibnode **heap_node =
+ xcalloc (cgraph_max_uid, sizeof (struct fibnode *));
+ int max_insns = ((HOST_WIDEST_INT) initial_insns
+ * (100 + PARAM_VALUE (PARAM_INLINE_UNIT_GROWTH)) / 100);
- if (!quiet_flag)
- fprintf (stderr, "\n\nMarking local functions:");
+ /* Put all inline candidates into the heap. */
- /* Figure out functions we want to assemble. */
for (node = cgraph_nodes; node; node = node->next)
{
- node->local.local = (!node->needed
- && DECL_SAVED_TREE (node->decl)
- && !TREE_PUBLIC (node->decl));
- if (node->local.local)
- announce_function (node->decl);
+ if (!node->local.inlinable || !node->callers
+ || node->local.disregard_inline_limits)
+ continue;
+
+ if (!cgraph_default_inline_p (node))
+ {
+ cgraph_set_inline_failed (node,
+ N_("--param max-inline-insns-single limit reached"));
+ continue;
+ }
+ heap_node[node->uid] =
+ fibheap_insert (heap, cgraph_estimate_growth (node), node);
+ }
+
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file, "\nDeciding on smaller functions:\n");
+ while (overall_insns <= max_insns && (node = fibheap_extract_min (heap)))
+ {
+ struct cgraph_edge *e, *next;
+ int old_insns = overall_insns;
+
+ heap_node[node->uid] = NULL;
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file,
+ "\nConsidering %s with %i insns\n"
+ " Estimated growth is %+i insns.\n",
+ cgraph_node_name (node), node->global.insns,
+ cgraph_estimate_growth (node));
+ if (!cgraph_default_inline_p (node))
+ {
+ cgraph_set_inline_failed (node,
+ N_("--param max-inline-insns-single limit reached after inlining into the callee"));
+ continue;
+ }
+ for (e = node->callers; e; e = next)
+ {
+ next = e->next_caller;
+ if (e->inline_failed)
+ {
+ struct cgraph_node *where;
+
+ if (cgraph_recursive_inlining_p (e->caller, e->callee,
+ &e->inline_failed)
+ || !cgraph_check_inline_limits (e->caller, e->callee,
+ &e->inline_failed))
+ {
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file, " Not inlining into %s:%s.\n",
+ cgraph_node_name (e->caller), e->inline_failed);
+ continue;
+ }
+ next = cgraph_mark_inline (e);
+ where = e->caller;
+ if (where->global.inlined_to)
+ where = where->global.inlined_to;
+
+ if (heap_node[where->uid])
+ fibheap_replace_key (heap, heap_node[where->uid],
+ cgraph_estimate_growth (where));
+
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file,
+ " Inlined into %s which now has %i insns.\n",
+ cgraph_node_name (e->caller),
+ e->caller->global.insns);
+ }
+ }
+
+ cgraph_decide_recursive_inlining (node);
+
+ /* Similarly all functions called by the function we just inlined
+ are now called more times; update keys. */
+ update_callee_keys (heap, heap_node, node);
+
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file,
+ " Inlined for a net change of %+i insns.\n",
+ overall_insns - old_insns);
}
+ while ((node = fibheap_extract_min (heap)) != NULL)
+ if (!node->local.disregard_inline_limits)
+ cgraph_set_inline_failed (node, N_("--param inline-unit-growth limit reached"));
+ fibheap_delete (heap);
+ free (heap_node);
}
-/* Decide what function should be inlined because they are invoked once
- (so inlining won't result in duplication of the code). */
+/* Decide on the inlining. We do so in the topological order to avoid
+ expenses on updating data structures. */
static void
-cgraph_mark_functions_to_inline_once ()
+cgraph_decide_inlining (void)
{
- struct cgraph_node *node, *node1;
+ struct cgraph_node *node;
+ int nnodes;
+ struct cgraph_node **order =
+ xcalloc (cgraph_n_nodes, sizeof (struct cgraph_node *));
+ int old_insns = 0;
+ int i;
- if (!quiet_flag)
- fprintf (stderr, "\n\nMarking functions to inline once:");
+ for (node = cgraph_nodes; node; node = node->next)
+ initial_insns += node->local.self_insns;
+ overall_insns = initial_insns;
+
+ nnodes = cgraph_postorder (order);
+
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file,
+ "\nDeciding on inlining. Starting with %i insns.\n",
+ initial_insns);
- /* Now look for function called only once and mark them to inline.
- From this point number of calls to given function won't grow. */
for (node = cgraph_nodes; node; node = node->next)
+ node->aux = 0;
+
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file, "\nInlining always_inline functions:\n");
+
+ /* In the first pass mark all always_inline edges. Do this with a priority
+ so none of our later choices will make this impossible. */
+ for (i = nnodes - 1; i >= 0; i--)
{
- if (node->callers && !node->callers->next_caller && !node->needed
- && node->local.can_inline_once)
+ struct cgraph_edge *e, *next;
+
+ node = order[i];
+
+ if (!node->local.disregard_inline_limits)
+ continue;
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file,
+ "\nConsidering %s %i insns (always inline)\n",
+ cgraph_node_name (node), node->global.insns);
+ old_insns = overall_insns;
+ for (e = node->callers; e; e = next)
{
- bool ok = true;
-
- /* Verify that we won't duplicate the caller. */
- for (node1 = node->callers->caller;
- node1->local.inline_many
- && node1->callers
- && ok;
- node1 = node1->callers->caller)
- if (node1->callers->next_caller || node1->needed)
- ok = false;
- if (ok)
+ next = e->next_caller;
+ if (!e->inline_failed)
+ continue;
+ if (cgraph_recursive_inlining_p (e->caller, e->callee,
+ &e->inline_failed))
+ continue;
+ cgraph_mark_inline_edge (e);
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file,
+ " Inlined into %s which now has %i insns.\n",
+ cgraph_node_name (e->caller),
+ e->caller->global.insns);
+ }
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file,
+ " Inlined for a net change of %+i insns.\n",
+ overall_insns - old_insns);
+ }
+
+ if (!flag_really_no_inline)
+ {
+ cgraph_decide_inlining_of_small_functions ();
+
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file, "\nDeciding on functions called once:\n");
+
+ /* And finally decide what functions are called once. */
+
+ for (i = nnodes - 1; i >= 0; i--)
+ {
+ node = order[i];
+
+ if (node->callers && !node->callers->next_caller && !node->needed
+ && node->local.inlinable && node->callers->inline_failed
+ && !DECL_EXTERNAL (node->decl) && !DECL_COMDAT (node->decl))
{
- node->global.inline_once = true;
- announce_function (node->decl);
+ bool ok = true;
+ struct cgraph_node *node1;
+
+ /* Verify that we won't duplicate the caller. */
+ for (node1 = node->callers->caller;
+ node1->callers && !node1->callers->inline_failed
+ && ok; node1 = node1->callers->caller)
+ if (node1->callers->next_caller || node1->needed)
+ ok = false;
+ if (ok)
+ {
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file,
+ "\nConsidering %s %i insns.\n"
+ " Called once from %s %i insns.\n",
+ cgraph_node_name (node), node->global.insns,
+ cgraph_node_name (node->callers->caller),
+ node->callers->caller->global.insns);
+
+ old_insns = overall_insns;
+
+ if (cgraph_check_inline_limits (node->callers->caller, node,
+ NULL))
+ {
+ cgraph_mark_inline (node->callers);
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file,
+ " Inlined into %s which now has %i insns"
+ " for a net change of %+i insns.\n",
+ cgraph_node_name (node->callers->caller),
+ node->callers->caller->global.insns,
+ overall_insns - old_insns);
+ }
+ else
+ {
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file,
+ " Inline limit reached, not inlined.\n");
+ }
+ }
}
}
}
+
+ /* We will never output extern functions we didn't inline.
+ ??? Perhaps we can prevent accounting of growth of external
+ inline functions. */
+ cgraph_remove_unreachable_nodes ();
+
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file,
+ "\nInlined %i calls, eliminated %i functions, "
+ "%i insns turned to %i insns.\n\n",
+ ncalls_inlined, nfunctions_inlined, initial_insns,
+ overall_insns);
+ free (order);
+}
+
+/* Decide on the inlining. We do so in the topological order to avoid
+ expenses on updating data structures. */
+
+static void
+cgraph_decide_inlining_incrementally (struct cgraph_node *node)
+{
+ struct cgraph_edge *e;
+
+ /* First of all look for always inline functions. */
+ for (e = node->callees; e; e = e->next_callee)
+ if (e->callee->local.disregard_inline_limits
+ && e->inline_failed
+ && !cgraph_recursive_inlining_p (node, e->callee, &e->inline_failed)
+ /* ??? It is possible that renaming variable removed the function body
+ in duplicate_decls. See gcc.c-torture/compile/20011119-2.c */
+ && DECL_SAVED_TREE (e->callee->decl))
+ cgraph_mark_inline (e);
+
+ /* Now do the automatic inlining. */
+ if (!flag_really_no_inline)
+ for (e = node->callees; e; e = e->next_callee)
+ if (e->callee->local.inlinable
+ && e->inline_failed
+ && !e->callee->local.disregard_inline_limits
+ && !cgraph_recursive_inlining_p (node, e->callee, &e->inline_failed)
+ && cgraph_check_inline_limits (node, e->callee, &e->inline_failed)
+ && DECL_SAVED_TREE (e->callee->decl))
+ {
+ if (cgraph_default_inline_p (e->callee))
+ cgraph_mark_inline (e);
+ else
+ e->inline_failed
+ = N_("--param max-inline-insns-single limit reached");
+ }
}
+/* Return true when CALLER_DECL should be inlined into CALLEE_DECL. */
+
+bool
+cgraph_inline_p (struct cgraph_edge *e, const char **reason)
+{
+ *reason = e->inline_failed;
+ return !e->inline_failed;
+}
+
+/* Expand all functions that must be output.
+
+ Attempt to topologically sort the nodes so function is output when
+ all called functions are already assembled to allow data to be
+ propagated across the callgraph. Use a stack to get smaller distance
+ between a function and its callees (later we may choose to use a more
+ sophisticated algorithm for function reordering; we will likely want
+ to use subsections to make the output functions appear in top-down
+ order). */
+
+static void
+cgraph_expand_all_functions (void)
+{
+ struct cgraph_node *node;
+ struct cgraph_node **order =
+ xcalloc (cgraph_n_nodes, sizeof (struct cgraph_node *));
+ int order_pos = 0, new_order_pos = 0;
+ int i;
+
+ cgraph_mark_functions_to_output ();
+
+ order_pos = cgraph_postorder (order);
+ if (order_pos != cgraph_n_nodes)
+ abort ();
+
+ /* Garbage collector may remove inline clones we eliminate during
+ optimization. So we must be sure to not reference them. */
+ for (i = 0; i < order_pos; i++)
+ if (order[i]->output)
+ order[new_order_pos++] = order[i];
+
+ for (i = new_order_pos - 1; i >= 0; i--)
+ {
+ node = order[i];
+ if (node->output)
+ {
+ if (!node->reachable)
+ abort ();
+ node->output = 0;
+ cgraph_expand_function (node);
+ }
+ }
+ free (order);
+}
+
+/* Mark all local functions.
+
+ A local function is one whose calls can occur only in the
+ current compilation unit and all its calls are explicit,
+ so we can change its calling convention.
+ We simply mark all static functions whose address is not taken
+ as local. */
+
+static void
+cgraph_mark_local_functions (void)
+{
+ struct cgraph_node *node;
+
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file, "\nMarking local functions:");
+
+ /* Figure out functions we want to assemble. */
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ node->local.local = (!node->needed
+ && DECL_SAVED_TREE (node->decl)
+ && !TREE_PUBLIC (node->decl));
+ if (cgraph_dump_file && node->local.local)
+ fprintf (cgraph_dump_file, " %s", cgraph_node_name (node));
+ }
+ if (cgraph_dump_file)
+ fprintf (cgraph_dump_file, "\n\n");
+}
+
+/* Return true when function body of DECL still needs to be kept around
+ for later re-use. */
+bool
+cgraph_preserve_function_body_p (tree decl)
+{
+ struct cgraph_node *node;
+ /* Keep the body; we're going to dump it. */
+ if (dump_enabled_p (TDI_all))
+ return true;
+ if (!cgraph_global_info_ready)
+ return (DECL_INLINE (decl) && !flag_really_no_inline);
+ /* Look if there is any clone around. */
+ for (node = cgraph_node (decl); node; node = node->next_clone)
+ if (node->global.inlined_to)
+ return true;
+ return false;
+}
+
/* Perform simple optimizations based on callgraph. */
void
-cgraph_optimize ()
+cgraph_optimize (void)
{
- struct cgraph_node *node;
- bool changed = true;
+#ifdef ENABLE_CHECKING
+ verify_cgraph ();
+#endif
+ if (!flag_unit_at_a_time)
+ return;
+ timevar_push (TV_CGRAPHOPT);
+ if (!quiet_flag)
+ fprintf (stderr, "Performing intraprocedural optimizations\n");
cgraph_mark_local_functions ();
+ if (cgraph_dump_file)
+ {
+ fprintf (cgraph_dump_file, "Marked ");
+ dump_cgraph (cgraph_dump_file);
+ }
- cgraph_mark_functions_to_inline_once ();
-
+ if (flag_inline_trees)
+ cgraph_decide_inlining ();
cgraph_global_info_ready = true;
+ if (cgraph_dump_file)
+ {
+ fprintf (cgraph_dump_file, "Optimized ");
+ dump_cgraph (cgraph_dump_file);
+ }
+ timevar_pop (TV_CGRAPHOPT);
+
+ /* Output everything. */
if (!quiet_flag)
- fprintf (stderr, "\n\nAssembling functions:");
-
- /* Output everything.
- ??? Our inline heuristic may decide to not inline functions previously
- marked as inlinable thus adding new function bodies that must be output.
- Later we should move all inlining decisions to callgraph code to make
- this impossible. */
- cgraph_expand_functions ();
- if (!quiet_flag)
- fprintf (stderr, "\n\nAssembling functions that failed to inline:");
- while (changed && !errorcount && !sorrycount)
+ fprintf (stderr, "Assembling functions:\n");
+#ifdef ENABLE_CHECKING
+ verify_cgraph ();
+#endif
+ cgraph_expand_all_functions ();
+ if (cgraph_dump_file)
+ {
+ fprintf (cgraph_dump_file, "\nFinal ");
+ dump_cgraph (cgraph_dump_file);
+ }
+#ifdef ENABLE_CHECKING
+ verify_cgraph ();
+ /* Double check that all inline clones are gone and that all
+ function bodies have been released from memory. */
+ if (flag_unit_at_a_time
+ && !dump_enabled_p (TDI_all)
+ && !(sorrycount || errorcount))
{
- changed = false;
+ struct cgraph_node *node;
+ bool error_found = false;
+
for (node = cgraph_nodes; node; node = node->next)
- {
- tree decl = node->decl;
- if (!node->origin
- && !TREE_ASM_WRITTEN (decl)
- && DECL_SAVED_TREE (decl)
- && !DECL_EXTERNAL (decl))
- {
- struct cgraph_edge *edge;
+ if (node->analyzed
+ && (node->global.inlined_to
+ || DECL_SAVED_TREE (node->decl)))
+ {
+ error_found = true;
+ dump_cgraph_node (stderr, node);
+ }
+ if (error_found)
+ internal_error ("Nodes with no released memory found.");
+ }
+#endif
+}
- for (edge = node->callers; edge; edge = edge->next_caller)
- if (TREE_ASM_WRITTEN (edge->caller->decl))
- {
- changed = true;
- cgraph_expand_function (node);
- break;
- }
- }
- }
+/* Generate and emit a static constructor or destructor. WHICH must be
+ one of 'I' or 'D'. BODY should be a STATEMENT_LIST containing
+ GENERIC statements. */
+
+void
+cgraph_build_static_cdtor (char which, tree body, int priority)
+{
+ static int counter = 0;
+ char which_buf[16];
+ tree decl, name, resdecl;
+
+ sprintf (which_buf, "%c_%d", which, counter++);
+ name = get_file_function_name_long (which_buf);
+
+ decl = build_decl (FUNCTION_DECL, name,
+ build_function_type (void_type_node, void_list_node));
+ current_function_decl = decl;
+
+ resdecl = build_decl (RESULT_DECL, NULL_TREE, void_type_node);
+ DECL_ARTIFICIAL (resdecl) = 1;
+ DECL_IGNORED_P (resdecl) = 1;
+ DECL_RESULT (decl) = resdecl;
+
+ allocate_struct_function (decl);
+
+ TREE_STATIC (decl) = 1;
+ TREE_USED (decl) = 1;
+ DECL_ARTIFICIAL (decl) = 1;
+ DECL_IGNORED_P (decl) = 1;
+ DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
+ DECL_SAVED_TREE (decl) = body;
+ TREE_PUBLIC (decl) = ! targetm.have_ctors_dtors;
+ DECL_UNINLINABLE (decl) = 1;
+
+ DECL_INITIAL (decl) = make_node (BLOCK);
+ TREE_USED (DECL_INITIAL (decl)) = 1;
+
+ DECL_SOURCE_LOCATION (decl) = input_location;
+ cfun->function_end_locus = input_location;
+
+ if (which == 'I')
+ DECL_STATIC_CONSTRUCTOR (decl) = 1;
+ else if (which == 'D')
+ DECL_STATIC_DESTRUCTOR (decl) = 1;
+ else
+ abort ();
+
+ gimplify_function_tree (decl);
+
+ /* ??? We will get called LATE in the compilation process. */
+ if (cgraph_global_info_ready)
+ tree_rest_of_compilation (decl, false);
+ else
+ cgraph_finalize_function (decl, 0);
+
+ if (targetm.have_ctors_dtors)
+ {
+ void (*fn) (rtx, int);
+
+ if (which == 'I')
+ fn = targetm.asm_out.constructor;
+ else
+ fn = targetm.asm_out.destructor;
+ fn (XEXP (DECL_RTL (decl), 0), priority);
}
}
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