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/* Inlining decision heuristics. Copyright (C) 2003, 2004, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. Contributed by Jan Hubicka This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see <http://www.gnu.org/licenses/>. */ /* Inlining decision heuristics We separate inlining decisions from the inliner itself and store it inside callgraph as so called inline plan. Refer to cgraph.c documentation about particular representation of inline plans in the callgraph. There are three major parts of this file: cgraph_mark_inline implementation This function allows to mark given call inline and performs necessary modifications of cgraph (production of the clones and updating overall statistics) inlining heuristics limits These functions allow to check that particular inlining is allowed by the limits specified by user (allowed function growth, overall unit growth and so on). inlining heuristics This is implementation of IPA pass aiming to get as much of benefit from inlining obeying the limits checked above. 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 by early inliner. The inliner itself is split into several passes: pass_inline_parameters This pass computes local properties of functions that are used by inliner: estimated function body size, whether function is inlinable at all and stack frame consumption. Before executing any of inliner passes, this local pass has to be applied to each function in the callgraph (ie run as subpass of some earlier IPA pass). The results are made out of date by any optimization applied on the function body. pass_early_inlining Simple local inlining pass inlining callees into current function. This pass makes no global whole compilation unit analysis and this when allowed to do inlining expanding code size it might result in unbounded growth of whole unit. The pass is run during conversion into SSA form. Only functions already converted into SSA form are inlined, so the conversion must happen in topological order on the callgraph (that is maintained by pass manager). The functions after inlining are early optimized so the early inliner sees unoptimized function itself, but all considered callees are already optimized allowing it to unfold abstraction penalty on C++ effectively and cheaply. pass_ipa_early_inlining With profiling, the early inlining is also necessary to reduce instrumentation costs on program with high abstraction penalty (doing many redundant calls). This can't happen in parallel with early optimization and profile instrumentation, because we would end up re-instrumenting already instrumented function bodies we brought in via inlining. To avoid this, this pass is executed as IPA pass before profiling. It is simple wrapper to pass_early_inlining and ensures first inlining. pass_ipa_inline This is the main pass implementing simple greedy algorithm to do inlining of small functions that results in overall growth of compilation unit and inlining of functions called once. The pass compute just so called inline plan (representation of inlining to be done in callgraph) and unlike early inlining it is not performing the inlining itself. pass_apply_inline This pass performs actual inlining according to pass_ipa_inline on given function. Possible the function body before inlining is saved when it is needed for further inlining later. */ #include "config.h" #include "system.h" #include "coretypes.h" #include "tm.h" #include "tree.h" #include "tree-inline.h" #include "langhooks.h" #include "flags.h" #include "cgraph.h" #include "diagnostic.h" #include "timevar.h" #include "params.h" #include "fibheap.h" #include "intl.h" #include "tree-pass.h" #include "hashtab.h" #include "coverage.h" #include "ggc.h" #include "tree-flow.h" #include "rtl.h" #include "ipa-prop.h" #include "except.h" #define MAX_TIME 1000000000 /* Mode incremental inliner operate on: In ALWAYS_INLINE only functions marked always_inline are inlined. This mode is used after detecting cycle during flattening. In SIZE mode, only functions that reduce function body size after inlining are inlined, this is used during early inlining. in ALL mode, everything is inlined. This is used during flattening. */ enum inlining_mode { INLINE_NONE = 0, INLINE_ALWAYS_INLINE, INLINE_SIZE_NORECURSIVE, INLINE_SIZE, INLINE_ALL }; static bool cgraph_decide_inlining_incrementally (struct cgraph_node *, enum inlining_mode, int); /* Statistics we collect about inlining algorithm. */ static int ncalls_inlined; static int nfunctions_inlined; static int overall_size; static gcov_type max_count, max_benefit; /* Holders of ipa cgraph hooks: */ static struct cgraph_node_hook_list *function_insertion_hook_holder; static inline struct inline_summary * inline_summary (struct cgraph_node *node) { return &node->local.inline_summary; } /* Estimate self time of the function after inlining WHAT into TO. */ static int cgraph_estimate_time_after_inlining (int frequency, struct cgraph_node *to, struct cgraph_node *what) { gcov_type time = (((gcov_type)what->global.time - inline_summary (what)->time_inlining_benefit) * frequency + CGRAPH_FREQ_BASE / 2) / CGRAPH_FREQ_BASE + to->global.time; if (time < 0) time = 0; if (time > MAX_TIME) time = MAX_TIME; return time; } /* Estimate self time 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) { int size = (what->global.size - inline_summary (what)->size_inlining_benefit) * times + to->global.size; gcc_assert (size >= 0); return size; } /* Scale frequency of NODE edges by FREQ_SCALE and increase loop nest by NEST. */ static void update_noncloned_frequencies (struct cgraph_node *node, int freq_scale, int nest) { struct cgraph_edge *e; /* We do not want to ignore high loop nest after freq drops to 0. */ if (!freq_scale) freq_scale = 1; for (e = node->callees; e; e = e->next_callee) { e->loop_nest += nest; e->frequency = e->frequency * (gcov_type) freq_scale / CGRAPH_FREQ_BASE; if (e->frequency > CGRAPH_FREQ_MAX) e->frequency = CGRAPH_FREQ_MAX; if (!e->inline_failed) update_noncloned_frequencies (e->callee, freq_scale, nest); } } /* 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, bool update_original) { HOST_WIDE_INT peak; if (duplicate) { /* 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 && cgraph_can_remove_if_no_direct_calls_p (e->callee) /* Don't reuse if more than one function shares a comdat group. If the other function(s) are needed, we need to emit even this function out of line. */ && !e->callee->same_comdat_group && !cgraph_new_nodes) { gcc_assert (!e->callee->global.inlined_to); if (e->callee->analyzed) { overall_size -= e->callee->global.size; nfunctions_inlined++; } duplicate = false; e->callee->local.externally_visible = false; update_noncloned_frequencies (e->callee, e->frequency, e->loop_nest); } else { struct cgraph_node *n; n = cgraph_clone_node (e->callee, e->count, e->frequency, e->loop_nest, update_original, NULL); 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; e->callee->global.stack_frame_offset = e->caller->global.stack_frame_offset + inline_summary (e->caller)->estimated_self_stack_size; peak = e->callee->global.stack_frame_offset + inline_summary (e->callee)->estimated_self_stack_size; if (e->callee->global.inlined_to->global.estimated_stack_size < peak) e->callee->global.inlined_to->global.estimated_stack_size = peak; /* Recursively clone all bodies. */ for (e = e->callee->callees; e; e = e->next_callee) if (!e->inline_failed) cgraph_clone_inlined_nodes (e, duplicate, update_original); } /* Mark edge E as inlined and update callgraph accordingly. UPDATE_ORIGINAL specify whether profile of original function should be updated. If any new indirect edges are discovered in the process, add them to NEW_EDGES, unless it is NULL. Return true iff any new callgraph edges were discovered as a result of inlining. */ static bool cgraph_mark_inline_edge (struct cgraph_edge *e, bool update_original, VEC (cgraph_edge_p, heap) **new_edges) { int old_size = 0, new_size = 0; struct cgraph_node *to = NULL, *what; struct cgraph_edge *curr = e; int freq; gcc_assert (e->inline_failed); e->inline_failed = CIF_OK; if (!e->callee->global.inlined) DECL_POSSIBLY_INLINED (e->callee->decl) = true; e->callee->global.inlined = true; cgraph_clone_inlined_nodes (e, true, update_original); what = e->callee; freq = e->frequency; /* Now update size of caller and all functions caller is inlined into. */ for (;e && !e->inline_failed; e = e->caller->callers) { to = e->caller; old_size = e->caller->global.size; new_size = cgraph_estimate_size_after_inlining (1, to, what); to->global.size = new_size; to->global.time = cgraph_estimate_time_after_inlining (freq, to, what); } gcc_assert (what->global.inlined_to == to); if (new_size > old_size) overall_size += new_size - old_size; ncalls_inlined++; if (flag_indirect_inlining) return ipa_propagate_indirect_call_infos (curr, new_edges); else return false; } /* 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; gcc_assert (!edge->call_stmt_cannot_inline_p); /* 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, true, NULL); if (e == edge) edge = next; } } return edge; } /* 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; bool self_recursive = false; if (node->global.estimated_growth != INT_MIN) return node->global.estimated_growth; for (e = node->callers; e; e = e->next_caller) { if (e->caller == node) self_recursive = true; if (e->inline_failed) growth += (cgraph_estimate_size_after_inlining (1, e->caller, node) - e->caller->global.size); } /* ??? Wrong for non-trivially 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 (cgraph_only_called_directly_p (node) && !DECL_EXTERNAL (node->decl) && !self_recursive) growth -= node->global.size; node->global.estimated_growth = growth; return growth; } /* Return false when inlining WHAT into TO is not good idea as it would cause too large growth of function bodies. When ONE_ONLY is true, assume that only one call site is going to be inlined, otherwise figure out how many call sites in TO calls WHAT and verify that all can be inlined. */ static bool cgraph_check_inline_limits (struct cgraph_node *to, struct cgraph_node *what, cgraph_inline_failed_t *reason, bool one_only) { int times = 0; struct cgraph_edge *e; int newsize; int limit; HOST_WIDE_INT stack_size_limit, inlined_stack; if (one_only) times = 1; else for (e = to->callees; e; e = e->next_callee) if (e->callee == what) times++; if (to->global.inlined_to) to = to->global.inlined_to; /* When inlining large function body called once into small function, take the inlined function as base for limiting the growth. */ if (inline_summary (to)->self_size > inline_summary(what)->self_size) limit = inline_summary (to)->self_size; else limit = inline_summary (what)->self_size; limit += limit * PARAM_VALUE (PARAM_LARGE_FUNCTION_GROWTH) / 100; /* Check the size after inlining against the function limits. But allow the function to shrink if it went over the limits by forced inlining. */ newsize = cgraph_estimate_size_after_inlining (times, to, what); if (newsize >= to->global.size && newsize > PARAM_VALUE (PARAM_LARGE_FUNCTION_INSNS) && newsize > limit) { if (reason) *reason = CIF_LARGE_FUNCTION_GROWTH_LIMIT; return false; } stack_size_limit = inline_summary (to)->estimated_self_stack_size; stack_size_limit += stack_size_limit * PARAM_VALUE (PARAM_STACK_FRAME_GROWTH) / 100; inlined_stack = (to->global.stack_frame_offset + inline_summary (to)->estimated_self_stack_size + what->global.estimated_stack_size); if (inlined_stack > stack_size_limit && inlined_stack > PARAM_VALUE (PARAM_LARGE_STACK_FRAME)) { if (reason) *reason = CIF_LARGE_STACK_FRAME_GROWTH_LIMIT; 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, cgraph_inline_failed_t *reason) { tree decl = n->decl; if (!flag_inline_small_functions && !DECL_DECLARED_INLINE_P (decl)) { if (reason) *reason = CIF_FUNCTION_NOT_INLINE_CANDIDATE; return false; } if (!n->analyzed) { if (reason) *reason = CIF_BODY_NOT_AVAILABLE; return false; } if (DECL_DECLARED_INLINE_P (decl)) { if (n->global.size >= MAX_INLINE_INSNS_SINGLE) { if (reason) *reason = CIF_MAX_INLINE_INSNS_SINGLE_LIMIT; return false; } } else { if (n->global.size >= MAX_INLINE_INSNS_AUTO) { if (reason) *reason = CIF_MAX_INLINE_INSNS_AUTO_LIMIT; return false; } } return true; } /* 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, cgraph_inline_failed_t *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 ? CIF_RECURSIVE_INLINING : CIF_UNSPECIFIED); return recursive; } /* A cost model driving the inlining heuristics in a way so the edges with smallest badness are inlined first. After each inlining is performed the costs of all caller edges of nodes affected are recomputed so the metrics may accurately depend on values such as number of inlinable callers of the function or function body size. */ static int cgraph_edge_badness (struct cgraph_edge *edge, bool dump) { gcov_type badness; int growth = (cgraph_estimate_size_after_inlining (1, edge->caller, edge->callee) - edge->caller->global.size); if (edge->callee->local.disregard_inline_limits) return INT_MIN; if (dump) { fprintf (dump_file, " Badness calculcation for %s -> %s\n", cgraph_node_name (edge->caller), cgraph_node_name (edge->callee)); fprintf (dump_file, " growth %i, time %i-%i, size %i-%i\n", growth, edge->callee->global.time, inline_summary (edge->callee)->time_inlining_benefit, edge->callee->global.size, inline_summary (edge->callee)->size_inlining_benefit); } /* Always prefer inlining saving code size. */ if (growth <= 0) { badness = INT_MIN - growth; if (dump) fprintf (dump_file, " %i: Growth %i < 0\n", (int) badness, growth); } /* When profiling is available, base priorities -(#calls / growth). So we optimize for overall number of "executed" inlined calls. */ else if (max_count) { badness = ((int) ((double) edge->count * INT_MIN / max_count / (max_benefit + 1)) * (inline_summary (edge->callee)->time_inlining_benefit + 1)) / growth; if (dump) { fprintf (dump_file, " %i (relative %f): profile info. Relative count %f" " * Relative benefit %f\n", (int) badness, (double) badness / INT_MIN, (double) edge->count / max_count, (double) (inline_summary (edge->callee)-> time_inlining_benefit + 1) / (max_benefit + 1)); } } /* When function local profile is available, base priorities on growth / frequency, so we optimize for overall frequency of inlined calls. This is not too accurate since while the call might be frequent within function, the function itself is infrequent. Other objective to optimize for is number of different calls inlined. We add the estimated growth after inlining all functions to bias the priorities slightly in this direction (so fewer times called functions of the same size gets priority). */ else if (flag_guess_branch_prob) { int div = edge->frequency * 100 / CGRAPH_FREQ_BASE + 1; int benefitperc; int growth_for_all; badness = growth * 10000; benefitperc = MIN (100 * inline_summary (edge->callee)->time_inlining_benefit / (edge->callee->global.time + 1) +1, 100); div *= benefitperc; /* Decrease badness if call is nested. */ /* Compress the range so we don't overflow. */ if (div > 10000) div = 10000 + ceil_log2 (div) - 8; if (div < 1) div = 1; if (badness > 0) badness /= div; growth_for_all = cgraph_estimate_growth (edge->callee); badness += growth_for_all; if (badness > INT_MAX) badness = INT_MAX; if (dump) { fprintf (dump_file, " %i: guessed profile. frequency %i, overall growth %i," " benefit %i%%, divisor %i\n", (int) badness, edge->frequency, growth_for_all, benefitperc, div); } } /* When function local profile is not available or it does not give useful information (ie frequency is zero), base the cost on loop nest and overall size growth, so we optimize for overall number of functions fully inlined in program. */ else { int nest = MIN (edge->loop_nest, 8); badness = cgraph_estimate_growth (edge->callee) * 256; /* Decrease badness if call is nested. */ if (badness > 0) badness >>= nest; else { badness <<= nest; } if (dump) fprintf (dump_file, " %i: no profile. nest %i\n", (int) badness, nest); } /* Make recursive inlining happen always after other inlining is done. */ if (cgraph_recursive_inlining_p (edge->caller, edge->callee, NULL)) return badness + 1; else return badness; } /* Recompute heap nodes for each of caller edge. */ static void update_caller_keys (fibheap_t heap, struct cgraph_node *node, bitmap updated_nodes) { struct cgraph_edge *edge; cgraph_inline_failed_t failed_reason; if (!node->local.inlinable || node->local.disregard_inline_limits || node->global.inlined_to) return; if (bitmap_bit_p (updated_nodes, node->uid)) return; bitmap_set_bit (updated_nodes, node->uid); node->global.estimated_growth = INT_MIN; if (!node->local.inlinable) return; /* See if there is something to do. */ for (edge = node->callers; edge; edge = edge->next_caller) if (edge->inline_failed) break; if (!edge) return; /* Prune out edges we won't inline into anymore. */ if (!cgraph_default_inline_p (node, &failed_reason)) { for (; edge; edge = edge->next_caller) if (edge->aux) { fibheap_delete_node (heap, (fibnode_t) edge->aux); edge->aux = NULL; if (edge->inline_failed) edge->inline_failed = failed_reason; } return; } for (; edge; edge = edge->next_caller) if (edge->inline_failed) { int badness = cgraph_edge_badness (edge, false); if (edge->aux) { fibnode_t n = (fibnode_t) edge->aux; gcc_assert (n->data == edge); if (n->key == badness) continue; /* fibheap_replace_key only decrease the keys. When we increase the key we do not update heap and instead re-insert the element once it becomes a minium of heap. */ if (badness < n->key) { fibheap_replace_key (heap, n, badness); gcc_assert (n->key == badness); continue; } } else edge->aux = fibheap_insert (heap, badness, edge); } } /* Recompute heap nodes for each of caller edges of each of callees. Walk recursively into all inline clones. */ static void update_callee_keys (fibheap_t heap, struct cgraph_node *node, bitmap updated_nodes) { struct cgraph_edge *e = node->callees; node->global.estimated_growth = INT_MIN; if (!e) return; while (true) if (!e->inline_failed && e->callee->callees) e = e->callee->callees; else { if (e->inline_failed) update_caller_keys (heap, e->callee, updated_nodes); if (e->next_callee) e = e->next_callee; else { do { if (e->caller == node) return; e = e->caller->callers; } while (!e->next_callee); e = e->next_callee; } } } /* Enqueue all recursive calls from NODE into priority queue depending on how likely we want to recursively inline the call. */ static void lookup_recursive_calls (struct cgraph_node *node, struct cgraph_node *where, fibheap_t heap) { static int priority; struct cgraph_edge *e; for (e = where->callees; e; e = e->next_callee) if (e->callee == node) { /* When profile feedback is available, prioritize by expected number of calls. Without profile feedback we maintain simple queue to order candidates via recursive depths. */ fibheap_insert (heap, !max_count ? priority++ : -(e->count / ((max_count + (1<<24) - 1) / (1<<24))), e); } for (e = where->callees; e; e = e->next_callee) if (!e->inline_failed) lookup_recursive_calls (node, e->callee, heap); } /* Decide on recursive inlining: in the case function has recursive calls, inline until body size reaches given argument. If any new indirect edges are discovered in the process, add them to *NEW_EDGES, unless NEW_EDGES is NULL. */ static bool cgraph_decide_recursive_inlining (struct cgraph_node *node, VEC (cgraph_edge_p, heap) **new_edges) { int limit = PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO); int max_depth = PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO); int probability = PARAM_VALUE (PARAM_MIN_INLINE_RECURSIVE_PROBABILITY); fibheap_t heap; struct cgraph_edge *e; struct cgraph_node *master_clone, *next; int depth = 0; int n = 0; if (optimize_function_for_size_p (DECL_STRUCT_FUNCTION (node->decl)) || (!flag_inline_functions && !DECL_DECLARED_INLINE_P (node->decl))) return false; 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 enough to be considered for inlining. */ if (!max_depth || cgraph_estimate_size_after_inlining (1, node, node) >= limit) return false; heap = fibheap_new (); lookup_recursive_calls (node, node, heap); if (fibheap_empty (heap)) { fibheap_delete (heap); return false; } if (dump_file) fprintf (dump_file, " Performing recursive inlining on %s\n", cgraph_node_name (node)); /* We need original clone to copy around. */ master_clone = cgraph_clone_node (node, node->count, CGRAPH_FREQ_BASE, 1, false, NULL); master_clone->needed = true; for (e = master_clone->callees; e; e = e->next_callee) if (!e->inline_failed) cgraph_clone_inlined_nodes (e, true, false); /* Do the inlining and update list of recursive call during process. */ while (!fibheap_empty (heap) && (cgraph_estimate_size_after_inlining (1, node, master_clone) <= limit)) { struct cgraph_edge *curr = (struct cgraph_edge *) fibheap_extract_min (heap); struct cgraph_node *cnode; depth = 1; for (cnode = curr->caller; cnode->global.inlined_to; cnode = cnode->callers->caller) if (node->decl == curr->callee->decl) depth++; if (depth > max_depth) { if (dump_file) fprintf (dump_file, " maximal depth reached\n"); continue; } if (max_count) { if (!cgraph_maybe_hot_edge_p (curr)) { if (dump_file) fprintf (dump_file, " Not inlining cold call\n"); continue; } if (curr->count * 100 / node->count < probability) { if (dump_file) fprintf (dump_file, " Probability of edge is too small\n"); continue; } } if (dump_file) { fprintf (dump_file, " Inlining call of depth %i", depth); if (node->count) { fprintf (dump_file, " called approx. %.2f times per call", (double)curr->count / node->count); } fprintf (dump_file, "\n"); } cgraph_redirect_edge_callee (curr, master_clone); cgraph_mark_inline_edge (curr, false, new_edges); lookup_recursive_calls (node, curr->callee, heap); n++; } if (!fibheap_empty (heap) && dump_file) fprintf (dump_file, " Recursive inlining growth limit met.\n"); fibheap_delete (heap); if (dump_file) fprintf (dump_file, "\n Inlined %i times, body grown from size %i to %i, time %i to %i\n", n, master_clone->global.size, node->global.size, master_clone->global.time, node->global.time); /* 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 = next) { next = node->next; if (node->global.inlined_to == master_clone) cgraph_remove_node (node); } cgraph_remove_node (master_clone); /* FIXME: Recursive inlining actually reduces number of calls of the function. At this place we should probably walk the function and inline clones and compensate the counts accordingly. This probably doesn't matter much in practice. */ return n > 0; } /* Set inline_failed for all callers of given function to REASON. */ static void cgraph_set_inline_failed (struct cgraph_node *node, cgraph_inline_failed_t reason) { struct cgraph_edge *e; if (dump_file) fprintf (dump_file, "Inlining failed: %s\n", cgraph_inline_failed_string (reason)); for (e = node->callers; e; e = e->next_caller) if (e->inline_failed) e->inline_failed = reason; } /* Given whole compilation unit estimate of INSNS, compute how large we can allow the unit to grow. */ static int compute_max_insns (int insns) { int max_insns = insns; if (max_insns < PARAM_VALUE (PARAM_LARGE_UNIT_INSNS)) max_insns = PARAM_VALUE (PARAM_LARGE_UNIT_INSNS); return ((HOST_WIDEST_INT) max_insns * (100 + PARAM_VALUE (PARAM_INLINE_UNIT_GROWTH)) / 100); } /* Compute badness of all edges in NEW_EDGES and add them to the HEAP. */ static void add_new_edges_to_heap (fibheap_t heap, VEC (cgraph_edge_p, heap) *new_edges) { while (VEC_length (cgraph_edge_p, new_edges) > 0) { struct cgraph_edge *edge = VEC_pop (cgraph_edge_p, new_edges); gcc_assert (!edge->aux); if (edge->callee->local.inlinable && cgraph_default_inline_p (edge->callee, &edge->inline_failed)) edge->aux = fibheap_insert (heap, cgraph_edge_badness (edge, false), edge); } } /* 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; struct cgraph_edge *edge; cgraph_inline_failed_t failed_reason; fibheap_t heap = fibheap_new (); bitmap updated_nodes = BITMAP_ALLOC (NULL); int min_size, max_size; VEC (cgraph_edge_p, heap) *new_indirect_edges = NULL; if (flag_indirect_inlining) new_indirect_edges = VEC_alloc (cgraph_edge_p, heap, 8); if (dump_file) fprintf (dump_file, "\nDeciding on smaller functions:\n"); /* Put all inline candidates into the heap. */ for (node = cgraph_nodes; node; node = node->next) { if (!node->local.inlinable || !node->callers || node->local.disregard_inline_limits) continue; if (dump_file) fprintf (dump_file, "Considering inline candidate %s.\n", cgraph_node_name (node)); node->global.estimated_growth = INT_MIN; if (!cgraph_default_inline_p (node, &failed_reason)) { cgraph_set_inline_failed (node, failed_reason); continue; } for (edge = node->callers; edge; edge = edge->next_caller) if (edge->inline_failed) { gcc_assert (!edge->aux); edge->aux = fibheap_insert (heap, cgraph_edge_badness (edge, false), edge); } } max_size = compute_max_insns (overall_size); min_size = overall_size; while (overall_size <= max_size && !fibheap_empty (heap)) { int old_size = overall_size; struct cgraph_node *where, *callee; int badness = fibheap_min_key (heap); int current_badness; int growth; cgraph_inline_failed_t not_good = CIF_OK; edge = (struct cgraph_edge *) fibheap_extract_min (heap); gcc_assert (edge->aux); edge->aux = NULL; if (!edge->inline_failed) continue; /* When updating the edge costs, we only decrease badness in the keys. When the badness increase, we keep the heap as it is and re-insert key now. */ current_badness = cgraph_edge_badness (edge, false); gcc_assert (current_badness >= badness); if (current_badness != badness) { edge->aux = fibheap_insert (heap, current_badness, edge); continue; } callee = edge->callee; growth = (cgraph_estimate_size_after_inlining (1, edge->caller, edge->callee) - edge->caller->global.size); if (dump_file) { fprintf (dump_file, "\nConsidering %s with %i size\n", cgraph_node_name (edge->callee), edge->callee->global.size); fprintf (dump_file, " to be inlined into %s in %s:%i\n" " Estimated growth after inlined into all callees is %+i insns.\n" " Estimated badness is %i, frequency %.2f.\n", cgraph_node_name (edge->caller), flag_wpa ? "unknown" : gimple_filename ((const_gimple) edge->call_stmt), flag_wpa ? -1 : gimple_lineno ((const_gimple) edge->call_stmt), cgraph_estimate_growth (edge->callee), badness, edge->frequency / (double)CGRAPH_FREQ_BASE); if (edge->count) fprintf (dump_file," Called "HOST_WIDEST_INT_PRINT_DEC"x\n", edge->count); if (dump_flags & TDF_DETAILS) cgraph_edge_badness (edge, true); } /* When not having profile info ready we don't weight by any way the position of call in procedure itself. This means if call of function A from function B seems profitable to inline, the recursive call of function A in inline copy of A in B will look profitable too and we end up inlining until reaching maximal function growth. This is not good idea so prohibit the recursive inlining. ??? When the frequencies are taken into account we might not need this restriction. We need to be cureful here, in some testcases, e.g. directivec.c in libcpp, we can estimate self recursive function to have negative growth for inlining completely. */ if (!edge->count) { where = edge->caller; while (where->global.inlined_to) { if (where->decl == edge->callee->decl) break; where = where->callers->caller; } if (where->global.inlined_to) { edge->inline_failed = (edge->callee->local.disregard_inline_limits ? CIF_RECURSIVE_INLINING : CIF_UNSPECIFIED); if (dump_file) fprintf (dump_file, " inline_failed:Recursive inlining performed only for function itself.\n"); continue; } } if (!cgraph_maybe_hot_edge_p (edge)) not_good = CIF_UNLIKELY_CALL; if (!flag_inline_functions && !DECL_DECLARED_INLINE_P (edge->callee->decl)) not_good = CIF_NOT_DECLARED_INLINED; if (optimize_function_for_size_p (DECL_STRUCT_FUNCTION(edge->caller->decl))) not_good = CIF_OPTIMIZING_FOR_SIZE; if (not_good && growth > 0 && cgraph_estimate_growth (edge->callee) > 0) { if (!cgraph_recursive_inlining_p (edge->caller, edge->callee, &edge->inline_failed)) { edge->inline_failed = not_good; if (dump_file) fprintf (dump_file, " inline_failed:%s.\n", cgraph_inline_failed_string (edge->inline_failed)); } continue; } if (!cgraph_default_inline_p (edge->callee, &edge->inline_failed)) { if (!cgraph_recursive_inlining_p (edge->caller, edge->callee, &edge->inline_failed)) { if (dump_file) fprintf (dump_file, " inline_failed:%s.\n", cgraph_inline_failed_string (edge->inline_failed)); } continue; } if (!tree_can_inline_p (edge)) { if (dump_file) fprintf (dump_file, " inline_failed:%s.\n", cgraph_inline_failed_string (edge->inline_failed)); continue; } if (cgraph_recursive_inlining_p (edge->caller, edge->callee, &edge->inline_failed)) { where = edge->caller; if (where->global.inlined_to) where = where->global.inlined_to; if (!cgraph_decide_recursive_inlining (where, flag_indirect_inlining ? &new_indirect_edges : NULL)) continue; if (flag_indirect_inlining) add_new_edges_to_heap (heap, new_indirect_edges); update_callee_keys (heap, where, updated_nodes); } else { struct cgraph_node *callee; if (edge->call_stmt_cannot_inline_p || !cgraph_check_inline_limits (edge->caller, edge->callee, &edge->inline_failed, true)) { if (dump_file) fprintf (dump_file, " Not inlining into %s:%s.\n", cgraph_node_name (edge->caller), cgraph_inline_failed_string (edge->inline_failed)); continue; } callee = edge->callee; cgraph_mark_inline_edge (edge, true, &new_indirect_edges); if (flag_indirect_inlining) add_new_edges_to_heap (heap, new_indirect_edges); update_callee_keys (heap, callee, updated_nodes); } where = edge->caller; if (where->global.inlined_to) where = where->global.inlined_to; /* Our profitability metric can depend on local properties such as number of inlinable calls and size of the function body. After inlining these properties might change for the function we inlined into (since it's body size changed) and for the functions called by function we inlined (since number of it inlinable callers might change). */ update_caller_keys (heap, where, updated_nodes); /* We removed one call of the function we just inlined. If offline copy is still needed, be sure to update the keys. */ if (callee != where && !callee->global.inlined_to) update_caller_keys (heap, callee, updated_nodes); bitmap_clear (updated_nodes); if (dump_file) { fprintf (dump_file, " Inlined into %s which now has size %i and self time %i," "net change of %+i.\n", cgraph_node_name (edge->caller), edge->caller->global.time, edge->caller->global.size, overall_size - old_size); } if (min_size > overall_size) { min_size = overall_size; max_size = compute_max_insns (min_size); if (dump_file) fprintf (dump_file, "New minimal size reached: %i\n", min_size); } } while ((edge = (struct cgraph_edge *) fibheap_extract_min (heap)) != NULL) { gcc_assert (edge->aux); edge->aux = NULL; if (!edge->callee->local.disregard_inline_limits && edge->inline_failed && !cgraph_recursive_inlining_p (edge->caller, edge->callee, &edge->inline_failed)) edge->inline_failed = CIF_INLINE_UNIT_GROWTH_LIMIT; } if (new_indirect_edges) VEC_free (cgraph_edge_p, heap, new_indirect_edges); fibheap_delete (heap); BITMAP_FREE (updated_nodes); } /* Decide on the inlining. We do so in the topological order to avoid expenses on updating data structures. */ static unsigned int cgraph_decide_inlining (void) { struct cgraph_node *node; int nnodes; struct cgraph_node **order = XCNEWVEC (struct cgraph_node *, cgraph_n_nodes); int old_size = 0; int i; bool redo_always_inline = true; int initial_size = 0; cgraph_remove_function_insertion_hook (function_insertion_hook_holder); if (in_lto_p && flag_indirect_inlining) ipa_update_after_lto_read (); max_count = 0; max_benefit = 0; for (node = cgraph_nodes; node; node = node->next) if (node->analyzed) { struct cgraph_edge *e; gcc_assert (inline_summary (node)->self_size == node->global.size); initial_size += node->global.size; for (e = node->callees; e; e = e->next_callee) if (max_count < e->count) max_count = e->count; if (max_benefit < inline_summary (node)->time_inlining_benefit) max_benefit = inline_summary (node)->time_inlining_benefit; } gcc_assert (in_lto_p || !max_count || (profile_info && flag_branch_probabilities)); overall_size = initial_size; nnodes = cgraph_postorder (order); if (dump_file) fprintf (dump_file, "\nDeciding on inlining. Starting with size %i.\n", initial_size); for (node = cgraph_nodes; node; node = node->next) node->aux = 0; if (dump_file) fprintf (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. */ while (redo_always_inline) { redo_always_inline = false; for (i = nnodes - 1; i >= 0; i--) { struct cgraph_edge *e, *next; node = order[i]; /* Handle nodes to be flattened, but don't update overall unit size. */ if (lookup_attribute ("flatten", DECL_ATTRIBUTES (node->decl)) != NULL) { if (dump_file) fprintf (dump_file, "Flattening %s\n", cgraph_node_name (node)); cgraph_decide_inlining_incrementally (node, INLINE_ALL, 0); } if (!node->local.disregard_inline_limits) continue; if (dump_file) fprintf (dump_file, "\nConsidering %s size:%i (always inline)\n", cgraph_node_name (node), node->global.size); old_size = overall_size; for (e = node->callers; e; e = next) { next = e->next_caller; if (!e->inline_failed || e->call_stmt_cannot_inline_p) continue; if (cgraph_recursive_inlining_p (e->caller, e->callee, &e->inline_failed)) continue; if (!tree_can_inline_p (e)) continue; if (cgraph_mark_inline_edge (e, true, NULL)) redo_always_inline = true; if (dump_file) fprintf (dump_file, " Inlined into %s which now has size %i.\n", cgraph_node_name (e->caller), e->caller->global.size); } /* Inlining self recursive function might introduce new calls to themselves we didn't see in the loop above. Fill in the proper reason why inline failed. */ for (e = node->callers; e; e = e->next_caller) if (e->inline_failed) e->inline_failed = CIF_RECURSIVE_INLINING; if (dump_file) fprintf (dump_file, " Inlined for a net change of %+i size.\n", overall_size - old_size); } } cgraph_decide_inlining_of_small_functions (); if (flag_inline_functions_called_once) { if (dump_file) fprintf (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 && cgraph_only_called_directly_p (node) && node->local.inlinable && node->callers->inline_failed && node->callers->caller != node && node->callers->caller->global.inlined_to != node && !node->callers->call_stmt_cannot_inline_p && !DECL_EXTERNAL (node->decl) && !DECL_COMDAT (node->decl)) { cgraph_inline_failed_t reason; old_size = overall_size; if (dump_file) { fprintf (dump_file, "\nConsidering %s size %i.\n", cgraph_node_name (node), node->global.size); fprintf (dump_file, " Called once from %s %i insns.\n", cgraph_node_name (node->callers->caller), node->callers->caller->global.size); } if (cgraph_check_inline_limits (node->callers->caller, node, &reason, false)) { cgraph_mark_inline (node->callers); if (dump_file) fprintf (dump_file, " Inlined into %s which now has %i size" " for a net change of %+i size.\n", cgraph_node_name (node->callers->caller), node->callers->caller->global.size, overall_size - old_size); } else { if (dump_file) fprintf (dump_file, " Not inlining: %s.\n", cgraph_inline_failed_string (reason)); } } } } /* Free ipa-prop structures if they are no longer needed. */ if (flag_indirect_inlining) free_all_ipa_structures_after_iinln (); if (dump_file) fprintf (dump_file, "\nInlined %i calls, eliminated %i functions, " "size %i turned to %i size.\n\n", ncalls_inlined, nfunctions_inlined, initial_size, overall_size); free (order); return 0; } /* Try to inline edge E from incremental inliner. MODE specifies mode of inliner. We are detecting cycles by storing mode of inliner into cgraph_node last time we visited it in the recursion. In general when mode is set, we have recursive inlining, but as an special case, we want to try harder inline ALWAYS_INLINE functions: consider callgraph a->b->c->b, with a being flatten, b being always inline. Flattening 'a' will collapse a->b->c before hitting cycle. To accommodate always inline, we however need to inline a->b->c->b. So after hitting cycle first time, we switch into ALWAYS_INLINE mode and stop inlining only after hitting ALWAYS_INLINE in ALWAY_INLINE mode. */ static bool try_inline (struct cgraph_edge *e, enum inlining_mode mode, int depth) { struct cgraph_node *callee = e->callee; enum inlining_mode callee_mode = (enum inlining_mode) (size_t) callee->aux; bool always_inline = e->callee->local.disregard_inline_limits; bool inlined = false; /* We've hit cycle? */ if (callee_mode) { /* It is first time we see it and we are not in ALWAY_INLINE only mode yet. and the function in question is always_inline. */ if (always_inline && mode != INLINE_ALWAYS_INLINE) { if (dump_file) { indent_to (dump_file, depth); fprintf (dump_file, "Hit cycle in %s, switching to always inline only.\n", cgraph_node_name (callee)); } mode = INLINE_ALWAYS_INLINE; } /* Otherwise it is time to give up. */ else { if (dump_file) { indent_to (dump_file, depth); fprintf (dump_file, "Not inlining %s into %s to avoid cycle.\n", cgraph_node_name (callee), cgraph_node_name (e->caller)); } e->inline_failed = (e->callee->local.disregard_inline_limits ? CIF_RECURSIVE_INLINING : CIF_UNSPECIFIED); return false; } } callee->aux = (void *)(size_t) mode; if (dump_file) { indent_to (dump_file, depth); fprintf (dump_file, " Inlining %s into %s.\n", cgraph_node_name (e->callee), cgraph_node_name (e->caller)); } if (e->inline_failed) { cgraph_mark_inline (e); /* In order to fully inline always_inline functions, we need to recurse here, since the inlined functions might not be processed by incremental inlining at all yet. Also flattening needs to be done recursively. */ if (mode == INLINE_ALL || always_inline) cgraph_decide_inlining_incrementally (e->callee, mode, depth + 1); inlined = true; } callee->aux = (void *)(size_t) callee_mode; return inlined; } /* Return true when N is leaf function. Accept cheap (pure&const) builtins in leaf functions. */ static bool leaf_node_p (struct cgraph_node *n) { struct cgraph_edge *e; for (e = n->callees; e; e = e->next_callee) if (!DECL_BUILT_IN (e->callee->decl) || (!TREE_READONLY (e->callee->decl) || DECL_PURE_P (e->callee->decl))) return false; return true; } /* Decide on the inlining. We do so in the topological order to avoid expenses on updating data structures. DEPTH is depth of recursion, used only for debug output. */ static bool cgraph_decide_inlining_incrementally (struct cgraph_node *node, enum inlining_mode mode, int depth) { struct cgraph_edge *e; bool inlined = false; cgraph_inline_failed_t failed_reason; enum inlining_mode old_mode; #ifdef ENABLE_CHECKING verify_cgraph_node (node); #endif old_mode = (enum inlining_mode) (size_t)node->aux; if (mode != INLINE_ALWAYS_INLINE && mode != INLINE_SIZE_NORECURSIVE && lookup_attribute ("flatten", DECL_ATTRIBUTES (node->decl)) != NULL) { if (dump_file) { indent_to (dump_file, depth); fprintf (dump_file, "Flattening %s\n", cgraph_node_name (node)); } mode = INLINE_ALL; } node->aux = (void *)(size_t) mode; /* First of all look for always inline functions. */ if (mode != INLINE_SIZE_NORECURSIVE) for (e = node->callees; e; e = e->next_callee) { if (!e->callee->local.disregard_inline_limits && (mode != INLINE_ALL || !e->callee->local.inlinable)) continue; if (e->call_stmt_cannot_inline_p) continue; /* When the edge is already inlined, we just need to recurse into it in order to fully flatten the leaves. */ if (!e->inline_failed && mode == INLINE_ALL) { inlined |= try_inline (e, mode, depth); continue; } if (dump_file) { indent_to (dump_file, depth); fprintf (dump_file, "Considering to always inline inline candidate %s.\n", cgraph_node_name (e->callee)); } if (cgraph_recursive_inlining_p (node, e->callee, &e->inline_failed)) { if (dump_file) { indent_to (dump_file, depth); fprintf (dump_file, "Not inlining: recursive call.\n"); } continue; } if (!tree_can_inline_p (e)) { if (dump_file) { indent_to (dump_file, depth); fprintf (dump_file, "Not inlining: %s", cgraph_inline_failed_string (e->inline_failed)); } continue; } if (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node->decl)) != gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e->callee->decl))) { if (dump_file) { indent_to (dump_file, depth); fprintf (dump_file, "Not inlining: SSA form does not match.\n"); } continue; } if (!e->callee->analyzed) { if (dump_file) { indent_to (dump_file, depth); fprintf (dump_file, "Not inlining: Function body no longer available.\n"); } continue; } inlined |= try_inline (e, mode, depth); } /* Now do the automatic inlining. */ if (mode != INLINE_ALL && mode != INLINE_ALWAYS_INLINE /* Never inline regular functions into always-inline functions during incremental inlining. */ && !node->local.disregard_inline_limits) { bitmap visited = BITMAP_ALLOC (NULL); for (e = node->callees; e; e = e->next_callee) { int allowed_growth = 0; if (!e->callee->local.inlinable || !e->inline_failed || e->callee->local.disregard_inline_limits) continue; /* We are inlining a function to all call-sites in node or to none. So visit each candidate only once. */ if (!bitmap_set_bit (visited, e->callee->uid)) continue; if (dump_file) fprintf (dump_file, "Considering inline candidate %s.\n", cgraph_node_name (e->callee)); if (cgraph_recursive_inlining_p (node, e->callee, &e->inline_failed)) { if (dump_file) { indent_to (dump_file, depth); fprintf (dump_file, "Not inlining: recursive call.\n"); } continue; } if (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node->decl)) != gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e->callee->decl))) { if (dump_file) { indent_to (dump_file, depth); fprintf (dump_file, "Not inlining: SSA form does not match.\n"); } continue; } if (cgraph_maybe_hot_edge_p (e) && leaf_node_p (e->callee) && optimize_function_for_speed_p (cfun)) allowed_growth = PARAM_VALUE (PARAM_EARLY_INLINING_INSNS); /* When the function body would grow and inlining the function won't eliminate the need for offline copy of the function, don't inline. */ if (((mode == INLINE_SIZE || mode == INLINE_SIZE_NORECURSIVE) || (!flag_inline_functions && !DECL_DECLARED_INLINE_P (e->callee->decl))) && (cgraph_estimate_size_after_inlining (1, e->caller, e->callee) > e->caller->global.size + allowed_growth) && cgraph_estimate_growth (e->callee) > allowed_growth) { if (dump_file) { indent_to (dump_file, depth); fprintf (dump_file, "Not inlining: code size would grow by %i.\n", cgraph_estimate_size_after_inlining (1, e->caller, e->callee) - e->caller->global.size); } continue; } if (!cgraph_check_inline_limits (node, e->callee, &e->inline_failed, false) || e->call_stmt_cannot_inline_p) { if (dump_file) { indent_to (dump_file, depth); fprintf (dump_file, "Not inlining: %s.\n", cgraph_inline_failed_string (e->inline_failed)); } continue; } if (!e->callee->analyzed) { if (dump_file) { indent_to (dump_file, depth); fprintf (dump_file, "Not inlining: Function body no longer available.\n"); } continue; } if (!tree_can_inline_p (e)) { if (dump_file) { indent_to (dump_file, depth); fprintf (dump_file, "Not inlining: %s.", cgraph_inline_failed_string (e->inline_failed)); } continue; } if (cgraph_default_inline_p (e->callee, &failed_reason)) inlined |= try_inline (e, mode, depth); } BITMAP_FREE (visited); } node->aux = (void *)(size_t) old_mode; return inlined; } /* Because inlining might remove no-longer reachable nodes, we need to keep the array visible to garbage collector to avoid reading collected out nodes. */ static int nnodes; static GTY ((length ("nnodes"))) struct cgraph_node **order; /* Do inlining of small functions. Doing so early helps profiling and other passes to be somewhat more effective and avoids some code duplication in later real inlining pass for testcases with very many function calls. */ static unsigned int cgraph_early_inlining (void) { struct cgraph_node *node = cgraph_node (current_function_decl); unsigned int todo = 0; int iterations = 0; if (sorrycount || errorcount) return 0; while (iterations < PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS) && cgraph_decide_inlining_incrementally (node, iterations ? INLINE_SIZE_NORECURSIVE : INLINE_SIZE, 0)) { timevar_push (TV_INTEGRATION); todo |= optimize_inline_calls (current_function_decl); iterations++; timevar_pop (TV_INTEGRATION); } if (dump_file) fprintf (dump_file, "Iterations: %i\n", iterations); cfun->always_inline_functions_inlined = true; return todo; } /* When inlining shall be performed. */ static bool cgraph_gate_early_inlining (void) { return flag_early_inlining; } struct gimple_opt_pass pass_early_inline = { { GIMPLE_PASS, "einline", /* name */ cgraph_gate_early_inlining, /* gate */ cgraph_early_inlining, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ TV_INLINE_HEURISTICS, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ TODO_dump_func /* todo_flags_finish */ } }; /* When inlining shall be performed. */ static bool cgraph_gate_ipa_early_inlining (void) { return (flag_early_inlining && !in_lto_p && (flag_branch_probabilities || flag_test_coverage || profile_arc_flag)); } /* IPA pass wrapper for early inlining pass. We need to run early inlining before tree profiling so we have stand alone IPA pass for doing so. */ struct simple_ipa_opt_pass pass_ipa_early_inline = { { SIMPLE_IPA_PASS, "einline_ipa", /* name */ cgraph_gate_ipa_early_inlining, /* gate */ NULL, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ TV_INLINE_HEURISTICS, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ TODO_dump_cgraph /* todo_flags_finish */ } }; /* See if statement might disappear after inlining. We are not terribly sophisficated, basically looking for simple abstraction penalty wrappers. */ static bool likely_eliminated_by_inlining_p (gimple stmt) { enum gimple_code code = gimple_code (stmt); switch (code) { case GIMPLE_RETURN: return true; case GIMPLE_ASSIGN: if (gimple_num_ops (stmt) != 2) return false; /* Casts of parameters, loads from parameters passed by reference and stores to return value or parameters are probably free after inlining. */ if (gimple_assign_rhs_code (stmt) == CONVERT_EXPR || gimple_assign_rhs_code (stmt) == NOP_EXPR || gimple_assign_rhs_code (stmt) == VIEW_CONVERT_EXPR || gimple_assign_rhs_class (stmt) == GIMPLE_SINGLE_RHS) { tree rhs = gimple_assign_rhs1 (stmt); tree lhs = gimple_assign_lhs (stmt); tree inner_rhs = rhs; tree inner_lhs = lhs; bool rhs_free = false; bool lhs_free = false; while (handled_component_p (inner_lhs) || TREE_CODE (inner_lhs) == INDIRECT_REF) inner_lhs = TREE_OPERAND (inner_lhs, 0); while (handled_component_p (inner_rhs) || TREE_CODE (inner_rhs) == ADDR_EXPR || TREE_CODE (inner_rhs) == INDIRECT_REF) inner_rhs = TREE_OPERAND (inner_rhs, 0); if (TREE_CODE (inner_rhs) == PARM_DECL || (TREE_CODE (inner_rhs) == SSA_NAME && SSA_NAME_IS_DEFAULT_DEF (inner_rhs) && TREE_CODE (SSA_NAME_VAR (inner_rhs)) == PARM_DECL)) rhs_free = true; if (rhs_free && is_gimple_reg (lhs)) lhs_free = true; if (((TREE_CODE (inner_lhs) == PARM_DECL || (TREE_CODE (inner_lhs) == SSA_NAME && SSA_NAME_IS_DEFAULT_DEF (inner_lhs) && TREE_CODE (SSA_NAME_VAR (inner_lhs)) == PARM_DECL)) && inner_lhs != lhs) || TREE_CODE (inner_lhs) == RESULT_DECL || (TREE_CODE (inner_lhs) == SSA_NAME && TREE_CODE (SSA_NAME_VAR (inner_lhs)) == RESULT_DECL)) lhs_free = true; if (lhs_free && (is_gimple_reg (rhs) || is_gimple_min_invariant (rhs))) rhs_free = true; if (lhs_free && rhs_free) return true; } return false; default: return false; } } /* Compute function body size parameters for NODE. */ static void estimate_function_body_sizes (struct cgraph_node *node) { gcov_type time = 0; gcov_type time_inlining_benefit = 0; int size = 0; int size_inlining_benefit = 0; basic_block bb; gimple_stmt_iterator bsi; struct function *my_function = DECL_STRUCT_FUNCTION (node->decl); tree arg; int freq; tree funtype = TREE_TYPE (node->decl); if (dump_file) fprintf (dump_file, "Analyzing function body size: %s\n", cgraph_node_name (node)); gcc_assert (my_function && my_function->cfg); FOR_EACH_BB_FN (bb, my_function) { freq = compute_call_stmt_bb_frequency (node->decl, bb); for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) { gimple stmt = gsi_stmt (bsi); int this_size = estimate_num_insns (stmt, &eni_size_weights); int this_time = estimate_num_insns (stmt, &eni_time_weights); if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " freq:%6i size:%3i time:%3i ", freq, this_size, this_time); print_gimple_stmt (dump_file, stmt, 0, 0); } this_time *= freq; time += this_time; size += this_size; if (likely_eliminated_by_inlining_p (stmt)) { size_inlining_benefit += this_size; time_inlining_benefit += this_time; if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, " Likely eliminated\n"); } gcc_assert (time >= 0); gcc_assert (size >= 0); } } time = (time + CGRAPH_FREQ_BASE / 2) / CGRAPH_FREQ_BASE; time_inlining_benefit = ((time_inlining_benefit + CGRAPH_FREQ_BASE / 2) / CGRAPH_FREQ_BASE); if (dump_file) fprintf (dump_file, "Overall function body time: %i-%i size: %i-%i\n", (int)time, (int)time_inlining_benefit, size, size_inlining_benefit); time_inlining_benefit += eni_time_weights.call_cost; size_inlining_benefit += eni_size_weights.call_cost; if (!VOID_TYPE_P (TREE_TYPE (funtype))) { int cost = estimate_move_cost (TREE_TYPE (funtype)); time_inlining_benefit += cost; size_inlining_benefit += cost; } for (arg = DECL_ARGUMENTS (node->decl); arg; arg = TREE_CHAIN (arg)) if (!VOID_TYPE_P (TREE_TYPE (arg))) { int cost = estimate_move_cost (TREE_TYPE (arg)); time_inlining_benefit += cost; size_inlining_benefit += cost; } if (time_inlining_benefit > MAX_TIME) time_inlining_benefit = MAX_TIME; if (time > MAX_TIME) time = MAX_TIME; inline_summary (node)->self_time = time; inline_summary (node)->self_size = size; if (dump_file) fprintf (dump_file, "With function call overhead time: %i-%i size: %i-%i\n", (int)time, (int)time_inlining_benefit, size, size_inlining_benefit); inline_summary (node)->time_inlining_benefit = time_inlining_benefit; inline_summary (node)->size_inlining_benefit = size_inlining_benefit; } /* Compute parameters of functions used by inliner. */ unsigned int compute_inline_parameters (struct cgraph_node *node) { HOST_WIDE_INT self_stack_size; gcc_assert (!node->global.inlined_to); /* Estimate the stack size for the function. But not at -O0 because estimated_stack_frame_size is a quadratic problem. */ self_stack_size = optimize ? estimated_stack_frame_size () : 0; inline_summary (node)->estimated_self_stack_size = self_stack_size; node->global.estimated_stack_size = self_stack_size; node->global.stack_frame_offset = 0; /* Can this function be inlined at all? */ node->local.inlinable = tree_inlinable_function_p (node->decl); if (node->local.inlinable && !node->local.disregard_inline_limits) node->local.disregard_inline_limits = DECL_DISREGARD_INLINE_LIMITS (node->decl); estimate_function_body_sizes (node); /* Inlining characteristics are maintained by the cgraph_mark_inline. */ node->global.time = inline_summary (node)->self_time; node->global.size = inline_summary (node)->self_size; return 0; } /* Compute parameters of functions used by inliner using current_function_decl. */ static unsigned int compute_inline_parameters_for_current (void) { compute_inline_parameters (cgraph_node (current_function_decl)); return 0; } struct gimple_opt_pass pass_inline_parameters = { { GIMPLE_PASS, "inline_param", /* name */ NULL, /* gate */ compute_inline_parameters_for_current,/* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ TV_INLINE_HEURISTICS, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ 0 /* todo_flags_finish */ } }; /* This function performs intraprocedural analyzis in NODE that is required to inline indirect calls. */ static void inline_indirect_intraprocedural_analysis (struct cgraph_node *node) { struct cgraph_edge *cs; if (!flag_ipa_cp) { ipa_initialize_node_params (node); ipa_detect_param_modifications (node); } ipa_analyze_params_uses (node); if (!flag_ipa_cp) for (cs = node->callees; cs; cs = cs->next_callee) { ipa_count_arguments (cs); ipa_compute_jump_functions (cs); } if (dump_file) { ipa_print_node_params (dump_file, node); ipa_print_node_jump_functions (dump_file, node); } } /* Note function body size. */ static void analyze_function (struct cgraph_node *node) { push_cfun (DECL_STRUCT_FUNCTION (node->decl)); current_function_decl = node->decl; compute_inline_parameters (node); if (flag_indirect_inlining) inline_indirect_intraprocedural_analysis (node); current_function_decl = NULL; pop_cfun (); } /* Called when new function is inserted to callgraph late. */ static void add_new_function (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED) { analyze_function (node); } /* Note function body size. */ static void inline_generate_summary (void) { struct cgraph_node *node; function_insertion_hook_holder = cgraph_add_function_insertion_hook (&add_new_function, NULL); if (flag_indirect_inlining) { ipa_register_cgraph_hooks (); ipa_check_create_node_params (); ipa_check_create_edge_args (); } for (node = cgraph_nodes; node; node = node->next) if (node->analyzed) analyze_function (node); return; } /* Apply inline plan to function. */ static unsigned int inline_transform (struct cgraph_node *node) { unsigned int todo = 0; struct cgraph_edge *e; /* FIXME: Currently the passmanager is adding inline transform more than once to some clones. This needs revisiting after WPA cleanups. */ if (cfun->after_inlining) return 0; /* We might need the body of this function so that we can expand it inline somewhere else. */ if (cgraph_preserve_function_body_p (node->decl)) save_inline_function_body (node); for (e = node->callees; e; e = e->next_callee) if (!e->inline_failed || warn_inline) break; if (e) { timevar_push (TV_INTEGRATION); todo = optimize_inline_calls (current_function_decl); timevar_pop (TV_INTEGRATION); } cfun->always_inline_functions_inlined = true; cfun->after_inlining = true; return todo | execute_fixup_cfg (); } /* Read inline summary. Jump functions are shared among ipa-cp and inliner, so when ipa-cp is active, we don't need to write them twice. */ static void inline_read_summary (void) { if (flag_indirect_inlining) { ipa_register_cgraph_hooks (); if (!flag_ipa_cp) ipa_prop_read_jump_functions (); } function_insertion_hook_holder = cgraph_add_function_insertion_hook (&add_new_function, NULL); } /* Write inline summary for node in SET. Jump functions are shared among ipa-cp and inliner, so when ipa-cp is active, we don't need to write them twice. */ static void inline_write_summary (cgraph_node_set set) { if (flag_indirect_inlining && !flag_ipa_cp) ipa_prop_write_jump_functions (set); } struct ipa_opt_pass_d pass_ipa_inline = { { IPA_PASS, "inline", /* name */ NULL, /* gate */ cgraph_decide_inlining, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ TV_INLINE_HEURISTICS, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ TODO_remove_functions, /* todo_flags_finish */ TODO_dump_cgraph | TODO_dump_func | TODO_remove_functions /* todo_flags_finish */ }, inline_generate_summary, /* generate_summary */ inline_write_summary, /* write_summary */ inline_read_summary, /* read_summary */ NULL, /* function_read_summary */ lto_ipa_fixup_call_notes, /* stmt_fixup */ 0, /* TODOs */ inline_transform, /* function_transform */ NULL, /* variable_transform */ }; #include "gt-ipa-inline.h"
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