From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001 From: upstream source tree Date: Sun, 15 Mar 2015 20:14:05 -0400 Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository. --- gcc/ipa-split.c | 1547 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1547 insertions(+) create mode 100644 gcc/ipa-split.c (limited to 'gcc/ipa-split.c') diff --git a/gcc/ipa-split.c b/gcc/ipa-split.c new file mode 100644 index 000000000..c71954db0 --- /dev/null +++ b/gcc/ipa-split.c @@ -0,0 +1,1547 @@ +/* Function splitting pass + Copyright (C) 2010, 2011 + 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 +. */ + +/* The purpose of this pass is to split function bodies to improve + inlining. I.e. for function of the form: + + func (...) + { + if (cheap_test) + something_small + else + something_big + } + + Produce: + + func.part (...) + { + something_big + } + + func (...) + { + if (cheap_test) + something_small + else + func.part (...); + } + + When func becomes inlinable and when cheap_test is often true, inlining func, + but not fund.part leads to performance improvement similar as inlining + original func while the code size growth is smaller. + + The pass is organized in three stages: + 1) Collect local info about basic block into BB_INFO structure and + compute function body estimated size and time. + 2) Via DFS walk find all possible basic blocks where we can split + and chose best one. + 3) If split point is found, split at the specified BB by creating a clone + and updating function to call it. + + The decisions what functions to split are in execute_split_functions + and consider_split. + + There are several possible future improvements for this pass including: + + 1) Splitting to break up large functions + 2) Splitting to reduce stack frame usage + 3) Allow split part of function to use values computed in the header part. + The values needs to be passed to split function, perhaps via same + interface as for nested functions or as argument. + 4) Support for simple rematerialization. I.e. when split part use + value computed in header from function parameter in very cheap way, we + can just recompute it. + 5) Support splitting of nested functions. + 6) Support non-SSA arguments. + 7) There is nothing preventing us from producing multiple parts of single function + when needed or splitting also the parts. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tree.h" +#include "target.h" +#include "cgraph.h" +#include "ipa-prop.h" +#include "tree-flow.h" +#include "tree-pass.h" +#include "flags.h" +#include "timevar.h" +#include "diagnostic.h" +#include "tree-dump.h" +#include "tree-inline.h" +#include "fibheap.h" +#include "params.h" +#include "gimple-pretty-print.h" + +/* Per basic block info. */ + +typedef struct +{ + unsigned int size; + unsigned int time; +} bb_info; +DEF_VEC_O(bb_info); +DEF_VEC_ALLOC_O(bb_info,heap); + +static VEC(bb_info, heap) *bb_info_vec; + +/* Description of split point. */ + +struct split_point +{ + /* Size of the partitions. */ + unsigned int header_time, header_size, split_time, split_size; + + /* SSA names that need to be passed into spit function. */ + bitmap ssa_names_to_pass; + + /* Basic block where we split (that will become entry point of new function. */ + basic_block entry_bb; + + /* Basic blocks we are splitting away. */ + bitmap split_bbs; + + /* True when return value is computed on split part and thus it needs + to be returned. */ + bool split_part_set_retval; +}; + +/* Best split point found. */ + +struct split_point best_split_point; + +/* Set of basic blocks that are not allowed to dominate a split point. */ + +static bitmap forbidden_dominators; + +static tree find_retval (basic_block return_bb); + +/* Callback for walk_stmt_load_store_addr_ops. If T is non-SSA automatic + variable, check it if it is present in bitmap passed via DATA. */ + +static bool +test_nonssa_use (gimple stmt ATTRIBUTE_UNUSED, tree t, void *data) +{ + t = get_base_address (t); + + if (!t || is_gimple_reg (t)) + return false; + + if (TREE_CODE (t) == PARM_DECL + || (TREE_CODE (t) == VAR_DECL + && auto_var_in_fn_p (t, current_function_decl)) + || TREE_CODE (t) == RESULT_DECL + || TREE_CODE (t) == LABEL_DECL) + return bitmap_bit_p ((bitmap)data, DECL_UID (t)); + + /* For DECL_BY_REFERENCE, the return value is actually a pointer. We want + to pretend that the value pointed to is actual result decl. */ + if ((TREE_CODE (t) == MEM_REF || INDIRECT_REF_P (t)) + && TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME + && TREE_CODE (SSA_NAME_VAR (TREE_OPERAND (t, 0))) == RESULT_DECL + && DECL_BY_REFERENCE (DECL_RESULT (current_function_decl))) + return + bitmap_bit_p ((bitmap)data, + DECL_UID (DECL_RESULT (current_function_decl))); + + return false; +} + +/* Dump split point CURRENT. */ + +static void +dump_split_point (FILE * file, struct split_point *current) +{ + fprintf (file, + "Split point at BB %i header time:%i header size: %i" + " split time: %i split size: %i\n bbs: ", + current->entry_bb->index, current->header_time, + current->header_size, current->split_time, current->split_size); + dump_bitmap (file, current->split_bbs); + fprintf (file, " SSA names to pass: "); + dump_bitmap (file, current->ssa_names_to_pass); +} + +/* Look for all BBs in header that might lead to the split part and verify + that they are not defining any non-SSA var used by the split part. + Parameters are the same as for consider_split. */ + +static bool +verify_non_ssa_vars (struct split_point *current, bitmap non_ssa_vars, + basic_block return_bb) +{ + bitmap seen = BITMAP_ALLOC (NULL); + VEC (basic_block,heap) *worklist = NULL; + edge e; + edge_iterator ei; + bool ok = true; + + FOR_EACH_EDGE (e, ei, current->entry_bb->preds) + if (e->src != ENTRY_BLOCK_PTR + && !bitmap_bit_p (current->split_bbs, e->src->index)) + { + VEC_safe_push (basic_block, heap, worklist, e->src); + bitmap_set_bit (seen, e->src->index); + } + + while (!VEC_empty (basic_block, worklist)) + { + gimple_stmt_iterator bsi; + basic_block bb = VEC_pop (basic_block, worklist); + + FOR_EACH_EDGE (e, ei, bb->preds) + if (e->src != ENTRY_BLOCK_PTR + && bitmap_set_bit (seen, e->src->index)) + { + gcc_checking_assert (!bitmap_bit_p (current->split_bbs, + e->src->index)); + VEC_safe_push (basic_block, heap, worklist, e->src); + } + for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) + { + gimple stmt = gsi_stmt (bsi); + if (is_gimple_debug (stmt)) + continue; + if (walk_stmt_load_store_addr_ops + (stmt, non_ssa_vars, test_nonssa_use, test_nonssa_use, + test_nonssa_use)) + { + ok = false; + goto done; + } + if (gimple_code (stmt) == GIMPLE_LABEL + && test_nonssa_use (stmt, gimple_label_label (stmt), + non_ssa_vars)) + { + ok = false; + goto done; + } + } + for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi)) + { + if (walk_stmt_load_store_addr_ops + (gsi_stmt (bsi), non_ssa_vars, test_nonssa_use, test_nonssa_use, + test_nonssa_use)) + { + ok = false; + goto done; + } + } + FOR_EACH_EDGE (e, ei, bb->succs) + { + if (e->dest != return_bb) + continue; + for (bsi = gsi_start_phis (return_bb); !gsi_end_p (bsi); + gsi_next (&bsi)) + { + gimple stmt = gsi_stmt (bsi); + tree op = gimple_phi_arg_def (stmt, e->dest_idx); + + if (!is_gimple_reg (gimple_phi_result (stmt))) + continue; + if (TREE_CODE (op) != SSA_NAME + && test_nonssa_use (stmt, op, non_ssa_vars)) + { + ok = false; + goto done; + } + } + } + } +done: + BITMAP_FREE (seen); + VEC_free (basic_block, heap, worklist); + return ok; +} + +/* If STMT is a call, check the callee against a list of forbidden + predicate functions. If a match is found, look for uses of the + call result in condition statements that compare against zero. + For each such use, find the block targeted by the condition + statement for the nonzero result, and set the bit for this block + in the forbidden dominators bitmap. The purpose of this is to avoid + selecting a split point where we are likely to lose the chance + to optimize away an unused function call. */ + +static void +check_forbidden_calls (gimple stmt) +{ + imm_use_iterator use_iter; + use_operand_p use_p; + tree lhs; + + /* At the moment, __builtin_constant_p is the only forbidden + predicate function call (see PR49642). */ + if (!gimple_call_builtin_p (stmt, BUILT_IN_CONSTANT_P)) + return; + + lhs = gimple_call_lhs (stmt); + + if (!lhs || TREE_CODE (lhs) != SSA_NAME) + return; + + FOR_EACH_IMM_USE_FAST (use_p, use_iter, lhs) + { + tree op1; + basic_block use_bb, forbidden_bb; + enum tree_code code; + edge true_edge, false_edge; + gimple use_stmt = USE_STMT (use_p); + + if (gimple_code (use_stmt) != GIMPLE_COND) + continue; + + /* Assuming canonical form for GIMPLE_COND here, with constant + in second position. */ + op1 = gimple_cond_rhs (use_stmt); + code = gimple_cond_code (use_stmt); + use_bb = gimple_bb (use_stmt); + + extract_true_false_edges_from_block (use_bb, &true_edge, &false_edge); + + /* We're only interested in comparisons that distinguish + unambiguously from zero. */ + if (!integer_zerop (op1) || code == LE_EXPR || code == GE_EXPR) + continue; + + if (code == EQ_EXPR) + forbidden_bb = false_edge->dest; + else + forbidden_bb = true_edge->dest; + + bitmap_set_bit (forbidden_dominators, forbidden_bb->index); + } +} + +/* If BB is dominated by any block in the forbidden dominators set, + return TRUE; else FALSE. */ + +static bool +dominated_by_forbidden (basic_block bb) +{ + unsigned dom_bb; + bitmap_iterator bi; + + EXECUTE_IF_SET_IN_BITMAP (forbidden_dominators, 1, dom_bb, bi) + { + if (dominated_by_p (CDI_DOMINATORS, bb, BASIC_BLOCK (dom_bb))) + return true; + } + + return false; +} + +/* We found an split_point CURRENT. NON_SSA_VARS is bitmap of all non ssa + variables used and RETURN_BB is return basic block. + See if we can split function here. */ + +static void +consider_split (struct split_point *current, bitmap non_ssa_vars, + basic_block return_bb) +{ + tree parm; + unsigned int num_args = 0; + unsigned int call_overhead; + edge e; + edge_iterator ei; + gimple_stmt_iterator bsi; + unsigned int i; + int incoming_freq = 0; + tree retval; + + if (dump_file && (dump_flags & TDF_DETAILS)) + dump_split_point (dump_file, current); + + FOR_EACH_EDGE (e, ei, current->entry_bb->preds) + if (!bitmap_bit_p (current->split_bbs, e->src->index)) + incoming_freq += EDGE_FREQUENCY (e); + + /* Do not split when we would end up calling function anyway. */ + if (incoming_freq + >= (ENTRY_BLOCK_PTR->frequency + * PARAM_VALUE (PARAM_PARTIAL_INLINING_ENTRY_PROBABILITY) / 100)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, + " Refused: incoming frequency is too large.\n"); + return; + } + + if (!current->header_size) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, " Refused: header empty\n"); + return; + } + + /* Verify that PHI args on entry are either virtual or all their operands + incoming from header are the same. */ + for (bsi = gsi_start_phis (current->entry_bb); !gsi_end_p (bsi); gsi_next (&bsi)) + { + gimple stmt = gsi_stmt (bsi); + tree val = NULL; + + if (!is_gimple_reg (gimple_phi_result (stmt))) + continue; + for (i = 0; i < gimple_phi_num_args (stmt); i++) + { + edge e = gimple_phi_arg_edge (stmt, i); + if (!bitmap_bit_p (current->split_bbs, e->src->index)) + { + tree edge_val = gimple_phi_arg_def (stmt, i); + if (val && edge_val != val) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, + " Refused: entry BB has PHI with multiple variants\n"); + return; + } + val = edge_val; + } + } + } + + + /* See what argument we will pass to the split function and compute + call overhead. */ + call_overhead = eni_size_weights.call_cost; + for (parm = DECL_ARGUMENTS (current_function_decl); parm; + parm = DECL_CHAIN (parm)) + { + if (!is_gimple_reg (parm)) + { + if (bitmap_bit_p (non_ssa_vars, DECL_UID (parm))) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, + " Refused: need to pass non-ssa param values\n"); + return; + } + } + else if (gimple_default_def (cfun, parm) + && bitmap_bit_p (current->ssa_names_to_pass, + SSA_NAME_VERSION (gimple_default_def + (cfun, parm)))) + { + if (!VOID_TYPE_P (TREE_TYPE (parm))) + call_overhead += estimate_move_cost (TREE_TYPE (parm)); + num_args++; + } + } + if (!VOID_TYPE_P (TREE_TYPE (current_function_decl))) + call_overhead += estimate_move_cost (TREE_TYPE (current_function_decl)); + + if (current->split_size <= call_overhead) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, + " Refused: split size is smaller than call overhead\n"); + return; + } + if (current->header_size + call_overhead + >= (unsigned int)(DECL_DECLARED_INLINE_P (current_function_decl) + ? MAX_INLINE_INSNS_SINGLE + : MAX_INLINE_INSNS_AUTO)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, + " Refused: header size is too large for inline candidate\n"); + return; + } + + /* FIXME: we currently can pass only SSA function parameters to the split + arguments. Once parm_adjustment infrastructure is supported by cloning, + we can pass more than that. */ + if (num_args != bitmap_count_bits (current->ssa_names_to_pass)) + { + + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, + " Refused: need to pass non-param values\n"); + return; + } + + /* When there are non-ssa vars used in the split region, see if they + are used in the header region. If so, reject the split. + FIXME: we can use nested function support to access both. */ + if (!bitmap_empty_p (non_ssa_vars) + && !verify_non_ssa_vars (current, non_ssa_vars, return_bb)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, + " Refused: split part has non-ssa uses\n"); + return; + } + + /* If the split point is dominated by a forbidden block, reject + the split. */ + if (!bitmap_empty_p (forbidden_dominators) + && dominated_by_forbidden (current->entry_bb)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, + " Refused: split point dominated by forbidden block\n"); + return; + } + + /* See if retval used by return bb is computed by header or split part. + When it is computed by split part, we need to produce return statement + in the split part and add code to header to pass it around. + + This is bit tricky to test: + 1) When there is no return_bb or no return value, we always pass + value around. + 2) Invariants are always computed by caller. + 3) For SSA we need to look if defining statement is in header or split part + 4) For non-SSA we need to look where the var is computed. */ + retval = find_retval (return_bb); + if (!retval) + current->split_part_set_retval = true; + else if (is_gimple_min_invariant (retval)) + current->split_part_set_retval = false; + /* Special case is value returned by reference we record as if it was non-ssa + set to result_decl. */ + else if (TREE_CODE (retval) == SSA_NAME + && TREE_CODE (SSA_NAME_VAR (retval)) == RESULT_DECL + && DECL_BY_REFERENCE (DECL_RESULT (current_function_decl))) + current->split_part_set_retval + = bitmap_bit_p (non_ssa_vars, DECL_UID (SSA_NAME_VAR (retval))); + else if (TREE_CODE (retval) == SSA_NAME) + current->split_part_set_retval + = (!SSA_NAME_IS_DEFAULT_DEF (retval) + && (bitmap_bit_p (current->split_bbs, + gimple_bb (SSA_NAME_DEF_STMT (retval))->index) + || gimple_bb (SSA_NAME_DEF_STMT (retval)) == return_bb)); + else if (TREE_CODE (retval) == PARM_DECL) + current->split_part_set_retval = false; + else if (TREE_CODE (retval) == VAR_DECL + || TREE_CODE (retval) == RESULT_DECL) + current->split_part_set_retval + = bitmap_bit_p (non_ssa_vars, DECL_UID (retval)); + else + current->split_part_set_retval = true; + + /* split_function fixes up at most one PHI non-virtual PHI node in return_bb, + for the return value. If there are other PHIs, give up. */ + if (return_bb != EXIT_BLOCK_PTR) + { + gimple_stmt_iterator psi; + + for (psi = gsi_start_phis (return_bb); !gsi_end_p (psi); gsi_next (&psi)) + if (is_gimple_reg (gimple_phi_result (gsi_stmt (psi))) + && !(retval + && current->split_part_set_retval + && TREE_CODE (retval) == SSA_NAME + && !DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)) + && SSA_NAME_DEF_STMT (retval) == gsi_stmt (psi))) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, + " Refused: return bb has extra PHIs\n"); + return; + } + } + + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, " Accepted!\n"); + + /* At the moment chose split point with lowest frequency and that leaves + out smallest size of header. + In future we might re-consider this heuristics. */ + if (!best_split_point.split_bbs + || best_split_point.entry_bb->frequency > current->entry_bb->frequency + || (best_split_point.entry_bb->frequency == current->entry_bb->frequency + && best_split_point.split_size < current->split_size)) + + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, " New best split point!\n"); + if (best_split_point.ssa_names_to_pass) + { + BITMAP_FREE (best_split_point.ssa_names_to_pass); + BITMAP_FREE (best_split_point.split_bbs); + } + best_split_point = *current; + best_split_point.ssa_names_to_pass = BITMAP_ALLOC (NULL); + bitmap_copy (best_split_point.ssa_names_to_pass, + current->ssa_names_to_pass); + best_split_point.split_bbs = BITMAP_ALLOC (NULL); + bitmap_copy (best_split_point.split_bbs, current->split_bbs); + } +} + +/* Return basic block containing RETURN statement. We allow basic blocks + of the form: + = tmp_var; + return + but return_bb can not be more complex than this. + If nothing is found, return EXIT_BLOCK_PTR. + + When there are multiple RETURN statement, chose one with return value, + since that one is more likely shared by multiple code paths. + + Return BB is special, because for function splitting it is the only + basic block that is duplicated in between header and split part of the + function. + + TODO: We might support multiple return blocks. */ + +static basic_block +find_return_bb (void) +{ + edge e; + basic_block return_bb = EXIT_BLOCK_PTR; + gimple_stmt_iterator bsi; + bool found_return = false; + tree retval = NULL_TREE; + + if (!single_pred_p (EXIT_BLOCK_PTR)) + return return_bb; + + e = single_pred_edge (EXIT_BLOCK_PTR); + for (bsi = gsi_last_bb (e->src); !gsi_end_p (bsi); gsi_prev (&bsi)) + { + gimple stmt = gsi_stmt (bsi); + if (gimple_code (stmt) == GIMPLE_LABEL || is_gimple_debug (stmt)) + ; + else if (gimple_code (stmt) == GIMPLE_ASSIGN + && found_return + && gimple_assign_single_p (stmt) + && (auto_var_in_fn_p (gimple_assign_rhs1 (stmt), + current_function_decl) + || is_gimple_min_invariant (gimple_assign_rhs1 (stmt))) + && retval == gimple_assign_lhs (stmt)) + ; + else if (gimple_code (stmt) == GIMPLE_RETURN) + { + found_return = true; + retval = gimple_return_retval (stmt); + } + else + break; + } + if (gsi_end_p (bsi) && found_return) + return_bb = e->src; + + return return_bb; +} + +/* Given return basic block RETURN_BB, see where return value is really + stored. */ +static tree +find_retval (basic_block return_bb) +{ + gimple_stmt_iterator bsi; + for (bsi = gsi_start_bb (return_bb); !gsi_end_p (bsi); gsi_next (&bsi)) + if (gimple_code (gsi_stmt (bsi)) == GIMPLE_RETURN) + return gimple_return_retval (gsi_stmt (bsi)); + else if (gimple_code (gsi_stmt (bsi)) == GIMPLE_ASSIGN) + return gimple_assign_rhs1 (gsi_stmt (bsi)); + return NULL; +} + +/* Callback for walk_stmt_load_store_addr_ops. If T is non-SSA automatic + variable, mark it as used in bitmap passed via DATA. + Return true when access to T prevents splitting the function. */ + +static bool +mark_nonssa_use (gimple stmt ATTRIBUTE_UNUSED, tree t, void *data) +{ + t = get_base_address (t); + + if (!t || is_gimple_reg (t)) + return false; + + /* At present we can't pass non-SSA arguments to split function. + FIXME: this can be relaxed by passing references to arguments. */ + if (TREE_CODE (t) == PARM_DECL) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, + "Cannot split: use of non-ssa function parameter.\n"); + return true; + } + + if ((TREE_CODE (t) == VAR_DECL + && auto_var_in_fn_p (t, current_function_decl)) + || TREE_CODE (t) == RESULT_DECL + || TREE_CODE (t) == LABEL_DECL) + bitmap_set_bit ((bitmap)data, DECL_UID (t)); + + /* For DECL_BY_REFERENCE, the return value is actually a pointer. We want + to pretend that the value pointed to is actual result decl. */ + if ((TREE_CODE (t) == MEM_REF || INDIRECT_REF_P (t)) + && TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME + && TREE_CODE (SSA_NAME_VAR (TREE_OPERAND (t, 0))) == RESULT_DECL + && DECL_BY_REFERENCE (DECL_RESULT (current_function_decl))) + return + bitmap_bit_p ((bitmap)data, + DECL_UID (DECL_RESULT (current_function_decl))); + + return false; +} + +/* Compute local properties of basic block BB we collect when looking for + split points. We look for ssa defs and store them in SET_SSA_NAMES, + for ssa uses and store them in USED_SSA_NAMES and for any non-SSA automatic + vars stored in NON_SSA_VARS. + + When BB has edge to RETURN_BB, collect uses in RETURN_BB too. + + Return false when BB contains something that prevents it from being put into + split function. */ + +static bool +visit_bb (basic_block bb, basic_block return_bb, + bitmap set_ssa_names, bitmap used_ssa_names, + bitmap non_ssa_vars) +{ + gimple_stmt_iterator bsi; + edge e; + edge_iterator ei; + bool can_split = true; + + for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) + { + gimple stmt = gsi_stmt (bsi); + tree op; + ssa_op_iter iter; + tree decl; + + if (is_gimple_debug (stmt)) + continue; + + /* FIXME: We can split regions containing EH. We can not however + split RESX, EH_DISPATCH and EH_POINTER referring to same region + into different partitions. This would require tracking of + EH regions and checking in consider_split_point if they + are not used elsewhere. */ + if (gimple_code (stmt) == GIMPLE_RESX) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "Cannot split: resx.\n"); + can_split = false; + } + if (gimple_code (stmt) == GIMPLE_EH_DISPATCH) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "Cannot split: eh dispatch.\n"); + can_split = false; + } + + /* Check builtins that prevent splitting. */ + if (gimple_code (stmt) == GIMPLE_CALL + && (decl = gimple_call_fndecl (stmt)) != NULL_TREE + && DECL_BUILT_IN (decl) + && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL) + switch (DECL_FUNCTION_CODE (decl)) + { + /* FIXME: once we will allow passing non-parm values to split part, + we need to be sure to handle correct builtin_stack_save and + builtin_stack_restore. At the moment we are safe; there is no + way to store builtin_stack_save result in non-SSA variable + since all calls to those are compiler generated. */ + case BUILT_IN_APPLY: + case BUILT_IN_APPLY_ARGS: + case BUILT_IN_VA_START: + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, + "Cannot split: builtin_apply and va_start.\n"); + can_split = false; + break; + case BUILT_IN_EH_POINTER: + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "Cannot split: builtin_eh_pointer.\n"); + can_split = false; + break; + default: + break; + } + + FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_DEF) + bitmap_set_bit (set_ssa_names, SSA_NAME_VERSION (op)); + FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE) + bitmap_set_bit (used_ssa_names, SSA_NAME_VERSION (op)); + can_split &= !walk_stmt_load_store_addr_ops (stmt, non_ssa_vars, + mark_nonssa_use, + mark_nonssa_use, + mark_nonssa_use); + } + for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi)) + { + gimple stmt = gsi_stmt (bsi); + unsigned int i; + + if (is_gimple_debug (stmt)) + continue; + if (!is_gimple_reg (gimple_phi_result (stmt))) + continue; + bitmap_set_bit (set_ssa_names, + SSA_NAME_VERSION (gimple_phi_result (stmt))); + for (i = 0; i < gimple_phi_num_args (stmt); i++) + { + tree op = gimple_phi_arg_def (stmt, i); + if (TREE_CODE (op) == SSA_NAME) + bitmap_set_bit (used_ssa_names, SSA_NAME_VERSION (op)); + } + can_split &= !walk_stmt_load_store_addr_ops (stmt, non_ssa_vars, + mark_nonssa_use, + mark_nonssa_use, + mark_nonssa_use); + } + /* Record also uses coming from PHI operand in return BB. */ + FOR_EACH_EDGE (e, ei, bb->succs) + if (e->dest == return_bb) + { + for (bsi = gsi_start_phis (return_bb); !gsi_end_p (bsi); gsi_next (&bsi)) + { + gimple stmt = gsi_stmt (bsi); + tree op = gimple_phi_arg_def (stmt, e->dest_idx); + + if (is_gimple_debug (stmt)) + continue; + if (!is_gimple_reg (gimple_phi_result (stmt))) + continue; + if (TREE_CODE (op) == SSA_NAME) + bitmap_set_bit (used_ssa_names, SSA_NAME_VERSION (op)); + else + can_split &= !mark_nonssa_use (stmt, op, non_ssa_vars); + } + } + return can_split; +} + +/* Stack entry for recursive DFS walk in find_split_point. */ + +typedef struct +{ + /* Basic block we are examining. */ + basic_block bb; + + /* SSA names set and used by the BB and all BBs reachable + from it via DFS walk. */ + bitmap set_ssa_names, used_ssa_names; + bitmap non_ssa_vars; + + /* All BBS visited from this BB via DFS walk. */ + bitmap bbs_visited; + + /* Last examined edge in DFS walk. Since we walk unoriented graph, + the value is up to sum of incoming and outgoing edges of BB. */ + unsigned int edge_num; + + /* Stack entry index of earliest BB reachable from current BB + or any BB visited later in DFS walk. */ + int earliest; + + /* Overall time and size of all BBs reached from this BB in DFS walk. */ + int overall_time, overall_size; + + /* When false we can not split on this BB. */ + bool can_split; +} stack_entry; +DEF_VEC_O(stack_entry); +DEF_VEC_ALLOC_O(stack_entry,heap); + + +/* Find all articulations and call consider_split on them. + OVERALL_TIME and OVERALL_SIZE is time and size of the function. + + We perform basic algorithm for finding an articulation in a graph + created from CFG by considering it to be an unoriented graph. + + The articulation is discovered via DFS walk. We collect earliest + basic block on stack that is reachable via backward edge. Articulation + is any basic block such that there is no backward edge bypassing it. + To reduce stack usage we maintain heap allocated stack in STACK vector. + AUX pointer of BB is set to index it appears in the stack or -1 once + it is visited and popped off the stack. + + The algorithm finds articulation after visiting the whole component + reachable by it. This makes it convenient to collect information about + the component used by consider_split. */ + +static void +find_split_points (int overall_time, int overall_size) +{ + stack_entry first; + VEC(stack_entry, heap) *stack = NULL; + basic_block bb; + basic_block return_bb = find_return_bb (); + struct split_point current; + + current.header_time = overall_time; + current.header_size = overall_size; + current.split_time = 0; + current.split_size = 0; + current.ssa_names_to_pass = BITMAP_ALLOC (NULL); + + first.bb = ENTRY_BLOCK_PTR; + first.edge_num = 0; + first.overall_time = 0; + first.overall_size = 0; + first.earliest = INT_MAX; + first.set_ssa_names = 0; + first.used_ssa_names = 0; + first.bbs_visited = 0; + VEC_safe_push (stack_entry, heap, stack, &first); + ENTRY_BLOCK_PTR->aux = (void *)(intptr_t)-1; + + while (!VEC_empty (stack_entry, stack)) + { + stack_entry *entry = VEC_last (stack_entry, stack); + + /* We are walking an acyclic graph, so edge_num counts + succ and pred edges together. However when considering + articulation, we want to have processed everything reachable + from articulation but nothing that reaches into it. */ + if (entry->edge_num == EDGE_COUNT (entry->bb->succs) + && entry->bb != ENTRY_BLOCK_PTR) + { + int pos = VEC_length (stack_entry, stack); + entry->can_split &= visit_bb (entry->bb, return_bb, + entry->set_ssa_names, + entry->used_ssa_names, + entry->non_ssa_vars); + if (pos <= entry->earliest && !entry->can_split + && dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, + "found articulation at bb %i but can not split\n", + entry->bb->index); + if (pos <= entry->earliest && entry->can_split) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "found articulation at bb %i\n", + entry->bb->index); + current.entry_bb = entry->bb; + current.ssa_names_to_pass = BITMAP_ALLOC (NULL); + bitmap_and_compl (current.ssa_names_to_pass, + entry->used_ssa_names, entry->set_ssa_names); + current.header_time = overall_time - entry->overall_time; + current.header_size = overall_size - entry->overall_size; + current.split_time = entry->overall_time; + current.split_size = entry->overall_size; + current.split_bbs = entry->bbs_visited; + consider_split (¤t, entry->non_ssa_vars, return_bb); + BITMAP_FREE (current.ssa_names_to_pass); + } + } + /* Do actual DFS walk. */ + if (entry->edge_num + < (EDGE_COUNT (entry->bb->succs) + + EDGE_COUNT (entry->bb->preds))) + { + edge e; + basic_block dest; + if (entry->edge_num < EDGE_COUNT (entry->bb->succs)) + { + e = EDGE_SUCC (entry->bb, entry->edge_num); + dest = e->dest; + } + else + { + e = EDGE_PRED (entry->bb, entry->edge_num + - EDGE_COUNT (entry->bb->succs)); + dest = e->src; + } + + entry->edge_num++; + + /* New BB to visit, push it to the stack. */ + if (dest != return_bb && dest != EXIT_BLOCK_PTR + && !dest->aux) + { + stack_entry new_entry; + + new_entry.bb = dest; + new_entry.edge_num = 0; + new_entry.overall_time + = VEC_index (bb_info, bb_info_vec, dest->index)->time; + new_entry.overall_size + = VEC_index (bb_info, bb_info_vec, dest->index)->size; + new_entry.earliest = INT_MAX; + new_entry.set_ssa_names = BITMAP_ALLOC (NULL); + new_entry.used_ssa_names = BITMAP_ALLOC (NULL); + new_entry.bbs_visited = BITMAP_ALLOC (NULL); + new_entry.non_ssa_vars = BITMAP_ALLOC (NULL); + new_entry.can_split = true; + bitmap_set_bit (new_entry.bbs_visited, dest->index); + VEC_safe_push (stack_entry, heap, stack, &new_entry); + dest->aux = (void *)(intptr_t)VEC_length (stack_entry, stack); + } + /* Back edge found, record the earliest point. */ + else if ((intptr_t)dest->aux > 0 + && (intptr_t)dest->aux < entry->earliest) + entry->earliest = (intptr_t)dest->aux; + } + /* We are done with examining the edges. Pop off the value from stack + and merge stuff we accumulate during the walk. */ + else if (entry->bb != ENTRY_BLOCK_PTR) + { + stack_entry *prev = VEC_index (stack_entry, stack, + VEC_length (stack_entry, stack) - 2); + + entry->bb->aux = (void *)(intptr_t)-1; + prev->can_split &= entry->can_split; + if (prev->set_ssa_names) + { + bitmap_ior_into (prev->set_ssa_names, entry->set_ssa_names); + bitmap_ior_into (prev->used_ssa_names, entry->used_ssa_names); + bitmap_ior_into (prev->bbs_visited, entry->bbs_visited); + bitmap_ior_into (prev->non_ssa_vars, entry->non_ssa_vars); + } + if (prev->earliest > entry->earliest) + prev->earliest = entry->earliest; + prev->overall_time += entry->overall_time; + prev->overall_size += entry->overall_size; + BITMAP_FREE (entry->set_ssa_names); + BITMAP_FREE (entry->used_ssa_names); + BITMAP_FREE (entry->bbs_visited); + BITMAP_FREE (entry->non_ssa_vars); + VEC_pop (stack_entry, stack); + } + else + VEC_pop (stack_entry, stack); + } + ENTRY_BLOCK_PTR->aux = NULL; + FOR_EACH_BB (bb) + bb->aux = NULL; + VEC_free (stack_entry, heap, stack); + BITMAP_FREE (current.ssa_names_to_pass); +} + +/* Split function at SPLIT_POINT. */ + +static void +split_function (struct split_point *split_point) +{ + VEC (tree, heap) *args_to_pass = NULL; + bitmap args_to_skip = BITMAP_ALLOC (NULL); + tree parm; + int num = 0; + struct cgraph_node *node, *cur_node = cgraph_node (current_function_decl); + basic_block return_bb = find_return_bb (); + basic_block call_bb; + gimple_stmt_iterator gsi; + gimple call; + edge e; + edge_iterator ei; + tree retval = NULL, real_retval = NULL; + bool split_part_return_p = false; + gimple last_stmt = NULL; + unsigned int i; + tree arg; + + if (dump_file) + { + fprintf (dump_file, "\n\nSplitting function at:\n"); + dump_split_point (dump_file, split_point); + } + + if (cur_node->local.can_change_signature + && !TYPE_ATTRIBUTES (TREE_TYPE (cur_node->decl))) + args_to_skip = BITMAP_ALLOC (NULL); + else + args_to_skip = NULL; + + /* Collect the parameters of new function and args_to_skip bitmap. */ + for (parm = DECL_ARGUMENTS (current_function_decl); + parm; parm = DECL_CHAIN (parm), num++) + if (args_to_skip + && (!is_gimple_reg (parm) + || !gimple_default_def (cfun, parm) + || !bitmap_bit_p (split_point->ssa_names_to_pass, + SSA_NAME_VERSION (gimple_default_def (cfun, + parm))))) + bitmap_set_bit (args_to_skip, num); + else + { + /* This parm might not have been used up to now, but is going to be + used, hence register it. */ + add_referenced_var (parm); + if (is_gimple_reg (parm)) + { + arg = gimple_default_def (cfun, parm); + if (!arg) + { + arg = make_ssa_name (parm, gimple_build_nop ()); + set_default_def (parm, arg); + } + } + else + arg = parm; + + if (!useless_type_conversion_p (DECL_ARG_TYPE (parm), TREE_TYPE (arg))) + arg = fold_convert (DECL_ARG_TYPE (parm), arg); + VEC_safe_push (tree, heap, args_to_pass, arg); + } + + /* See if the split function will return. */ + FOR_EACH_EDGE (e, ei, return_bb->preds) + if (bitmap_bit_p (split_point->split_bbs, e->src->index)) + break; + if (e) + split_part_return_p = true; + + /* Add return block to what will become the split function. + We do not return; no return block is needed. */ + if (!split_part_return_p) + ; + /* We have no return block, so nothing is needed. */ + else if (return_bb == EXIT_BLOCK_PTR) + ; + /* When we do not want to return value, we need to construct + new return block with empty return statement. + FIXME: Once we are able to change return type, we should change function + to return void instead of just outputting function with undefined return + value. For structures this affects quality of codegen. */ + else if (!split_point->split_part_set_retval + && find_retval (return_bb)) + { + bool redirected = true; + basic_block new_return_bb = create_basic_block (NULL, 0, return_bb); + gimple_stmt_iterator gsi = gsi_start_bb (new_return_bb); + gsi_insert_after (&gsi, gimple_build_return (NULL), GSI_NEW_STMT); + while (redirected) + { + redirected = false; + FOR_EACH_EDGE (e, ei, return_bb->preds) + if (bitmap_bit_p (split_point->split_bbs, e->src->index)) + { + new_return_bb->count += e->count; + new_return_bb->frequency += EDGE_FREQUENCY (e); + redirect_edge_and_branch (e, new_return_bb); + redirected = true; + break; + } + } + e = make_edge (new_return_bb, EXIT_BLOCK_PTR, 0); + e->probability = REG_BR_PROB_BASE; + e->count = new_return_bb->count; + bitmap_set_bit (split_point->split_bbs, new_return_bb->index); + } + /* When we pass around the value, use existing return block. */ + else + bitmap_set_bit (split_point->split_bbs, return_bb->index); + + /* If RETURN_BB has virtual operand PHIs, they must be removed and the + virtual operand marked for renaming as we change the CFG in a way that + tree-inline is not able to compensate for. + + Note this can happen whether or not we have a return value. If we have + a return value, then RETURN_BB may have PHIs for real operands too. */ + if (return_bb != EXIT_BLOCK_PTR) + { + for (gsi = gsi_start_phis (return_bb); !gsi_end_p (gsi);) + { + gimple stmt = gsi_stmt (gsi); + if (is_gimple_reg (gimple_phi_result (stmt))) + { + gsi_next (&gsi); + continue; + } + mark_virtual_phi_result_for_renaming (stmt); + remove_phi_node (&gsi, true); + } + } + + /* Now create the actual clone. */ + rebuild_cgraph_edges (); + node = cgraph_function_versioning (cur_node, NULL, NULL, args_to_skip, + split_point->split_bbs, + split_point->entry_bb, "part"); + /* For usual cloning it is enough to clear builtin only when signature + changes. For partial inlining we however can not expect the part + of builtin implementation to have same semantic as the whole. */ + if (DECL_BUILT_IN (node->decl)) + { + DECL_BUILT_IN_CLASS (node->decl) = NOT_BUILT_IN; + DECL_FUNCTION_CODE (node->decl) = (enum built_in_function) 0; + } + cgraph_node_remove_callees (cur_node); + if (!split_part_return_p) + TREE_THIS_VOLATILE (node->decl) = 1; + if (dump_file) + dump_function_to_file (node->decl, dump_file, dump_flags); + + /* Create the basic block we place call into. It is the entry basic block + split after last label. */ + call_bb = split_point->entry_bb; + for (gsi = gsi_start_bb (call_bb); !gsi_end_p (gsi);) + if (gimple_code (gsi_stmt (gsi)) == GIMPLE_LABEL) + { + last_stmt = gsi_stmt (gsi); + gsi_next (&gsi); + } + else + break; + e = split_block (split_point->entry_bb, last_stmt); + remove_edge (e); + + /* Produce the call statement. */ + gsi = gsi_last_bb (call_bb); + FOR_EACH_VEC_ELT (tree, args_to_pass, i, arg) + if (!is_gimple_val (arg)) + { + arg = force_gimple_operand_gsi (&gsi, arg, true, NULL_TREE, + false, GSI_CONTINUE_LINKING); + VEC_replace (tree, args_to_pass, i, arg); + } + call = gimple_build_call_vec (node->decl, args_to_pass); + gimple_set_block (call, DECL_INITIAL (current_function_decl)); + + /* We avoid address being taken on any variable used by split part, + so return slot optimization is always possible. Moreover this is + required to make DECL_BY_REFERENCE work. */ + if (aggregate_value_p (DECL_RESULT (current_function_decl), + TREE_TYPE (current_function_decl))) + gimple_call_set_return_slot_opt (call, true); + + /* Update return value. This is bit tricky. When we do not return, + do nothing. When we return we might need to update return_bb + or produce a new return statement. */ + if (!split_part_return_p) + gsi_insert_after (&gsi, call, GSI_NEW_STMT); + else + { + e = make_edge (call_bb, return_bb, + return_bb == EXIT_BLOCK_PTR ? 0 : EDGE_FALLTHRU); + e->count = call_bb->count; + e->probability = REG_BR_PROB_BASE; + + /* If there is return basic block, see what value we need to store + return value into and put call just before it. */ + if (return_bb != EXIT_BLOCK_PTR) + { + real_retval = retval = find_retval (return_bb); + + if (real_retval && split_point->split_part_set_retval) + { + gimple_stmt_iterator psi; + + /* See if we need new SSA_NAME for the result. + When DECL_BY_REFERENCE is true, retval is actually pointer to + return value and it is constant in whole function. */ + if (TREE_CODE (retval) == SSA_NAME + && !DECL_BY_REFERENCE (DECL_RESULT (current_function_decl))) + { + retval = make_ssa_name (SSA_NAME_VAR (retval), call); + + /* See if there is PHI defining return value. */ + for (psi = gsi_start_phis (return_bb); + !gsi_end_p (psi); gsi_next (&psi)) + if (is_gimple_reg (gimple_phi_result (gsi_stmt (psi)))) + break; + + /* When there is PHI, just update its value. */ + if (TREE_CODE (retval) == SSA_NAME + && !gsi_end_p (psi)) + add_phi_arg (gsi_stmt (psi), retval, e, UNKNOWN_LOCATION); + /* Otherwise update the return BB itself. + find_return_bb allows at most one assignment to return value, + so update first statement. */ + else + { + gimple_stmt_iterator bsi; + for (bsi = gsi_start_bb (return_bb); !gsi_end_p (bsi); + gsi_next (&bsi)) + if (gimple_code (gsi_stmt (bsi)) == GIMPLE_RETURN) + { + gimple_return_set_retval (gsi_stmt (bsi), retval); + break; + } + else if (gimple_code (gsi_stmt (bsi)) == GIMPLE_ASSIGN) + { + gimple_assign_set_rhs1 (gsi_stmt (bsi), retval); + break; + } + update_stmt (gsi_stmt (bsi)); + } + } + if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl))) + gimple_call_set_lhs (call, build_simple_mem_ref (retval)); + else + gimple_call_set_lhs (call, retval); + } + gsi_insert_after (&gsi, call, GSI_NEW_STMT); + } + /* We don't use return block (there is either no return in function or + multiple of them). So create new basic block with return statement. + */ + else + { + gimple ret; + if (split_point->split_part_set_retval + && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl)))) + { + retval = DECL_RESULT (current_function_decl); + + /* We use temporary register to hold value when aggregate_value_p + is false. Similarly for DECL_BY_REFERENCE we must avoid extra + copy. */ + if (!aggregate_value_p (retval, TREE_TYPE (current_function_decl)) + && !DECL_BY_REFERENCE (retval)) + retval = create_tmp_reg (TREE_TYPE (retval), NULL); + if (is_gimple_reg (retval)) + { + /* When returning by reference, there is only one SSA name + assigned to RESULT_DECL (that is pointer to return value). + Look it up or create new one if it is missing. */ + if (DECL_BY_REFERENCE (retval)) + { + tree retval_name; + if ((retval_name = gimple_default_def (cfun, retval)) + != NULL) + retval = retval_name; + else + { + retval_name = make_ssa_name (retval, + gimple_build_nop ()); + set_default_def (retval, retval_name); + retval = retval_name; + } + } + /* Otherwise produce new SSA name for return value. */ + else + retval = make_ssa_name (retval, call); + } + if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl))) + gimple_call_set_lhs (call, build_simple_mem_ref (retval)); + else + gimple_call_set_lhs (call, retval); + } + gsi_insert_after (&gsi, call, GSI_NEW_STMT); + ret = gimple_build_return (retval); + gsi_insert_after (&gsi, ret, GSI_NEW_STMT); + } + } + free_dominance_info (CDI_DOMINATORS); + free_dominance_info (CDI_POST_DOMINATORS); + compute_inline_parameters (node); +} + +/* Execute function splitting pass. */ + +static unsigned int +execute_split_functions (void) +{ + gimple_stmt_iterator bsi; + basic_block bb; + int overall_time = 0, overall_size = 0; + int todo = 0; + struct cgraph_node *node = cgraph_node (current_function_decl); + + if (flags_from_decl_or_type (current_function_decl) & ECF_NORETURN) + { + if (dump_file) + fprintf (dump_file, "Not splitting: noreturn function.\n"); + return 0; + } + if (MAIN_NAME_P (DECL_NAME (current_function_decl))) + { + if (dump_file) + fprintf (dump_file, "Not splitting: main function.\n"); + return 0; + } + /* This can be relaxed; function might become inlinable after splitting + away the uninlinable part. */ + if (!node->local.inlinable) + { + if (dump_file) + fprintf (dump_file, "Not splitting: not inlinable.\n"); + return 0; + } + if (node->local.disregard_inline_limits) + { + if (dump_file) + fprintf (dump_file, "Not splitting: disregarding inline limits.\n"); + return 0; + } + /* This can be relaxed; most of versioning tests actually prevents + a duplication. */ + if (!tree_versionable_function_p (current_function_decl)) + { + if (dump_file) + fprintf (dump_file, "Not splitting: not versionable.\n"); + return 0; + } + /* FIXME: we could support this. */ + if (DECL_STRUCT_FUNCTION (current_function_decl)->static_chain_decl) + { + if (dump_file) + fprintf (dump_file, "Not splitting: nested function.\n"); + return 0; + } + + /* See if it makes sense to try to split. + It makes sense to split if we inline, that is if we have direct calls to + handle or direct calls are possibly going to appear as result of indirect + inlining or LTO. Also handle -fprofile-generate as LTO to allow non-LTO + training for LTO -fprofile-use build. + + Note that we are not completely conservative about disqualifying functions + called once. It is possible that the caller is called more then once and + then inlining would still benefit. */ + if ((!node->callers || !node->callers->next_caller) + && !node->address_taken + && (!flag_lto || !node->local.externally_visible)) + { + if (dump_file) + fprintf (dump_file, "Not splitting: not called directly " + "or called once.\n"); + return 0; + } + + /* FIXME: We can actually split if splitting reduces call overhead. */ + if (!flag_inline_small_functions + && !DECL_DECLARED_INLINE_P (current_function_decl)) + { + if (dump_file) + fprintf (dump_file, "Not splitting: not autoinlining and function" + " is not inline.\n"); + return 0; + } + + /* Initialize bitmap to track forbidden calls. */ + forbidden_dominators = BITMAP_ALLOC (NULL); + calculate_dominance_info (CDI_DOMINATORS); + + /* Compute local info about basic blocks and determine function size/time. */ + VEC_safe_grow_cleared (bb_info, heap, bb_info_vec, last_basic_block + 1); + memset (&best_split_point, 0, sizeof (best_split_point)); + FOR_EACH_BB (bb) + { + int time = 0; + int size = 0; + int freq = compute_call_stmt_bb_frequency (current_function_decl, bb); + + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "Basic block %i\n", bb->index); + + for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) + { + int this_time, this_size; + gimple stmt = gsi_stmt (bsi); + + this_size = estimate_num_insns (stmt, &eni_size_weights); + this_time = estimate_num_insns (stmt, &eni_time_weights) * freq; + size += this_size; + time += this_time; + check_forbidden_calls (stmt); + + 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); + } + } + overall_time += time; + overall_size += size; + VEC_index (bb_info, bb_info_vec, bb->index)->time = time; + VEC_index (bb_info, bb_info_vec, bb->index)->size = size; + } + find_split_points (overall_time, overall_size); + if (best_split_point.split_bbs) + { + split_function (&best_split_point); + BITMAP_FREE (best_split_point.ssa_names_to_pass); + BITMAP_FREE (best_split_point.split_bbs); + todo = TODO_update_ssa | TODO_cleanup_cfg; + } + BITMAP_FREE (forbidden_dominators); + VEC_free (bb_info, heap, bb_info_vec); + bb_info_vec = NULL; + return todo; +} + +/* Gate function splitting pass. When doing profile feedback, we want + to execute the pass after profiling is read. So disable one in + early optimization. */ + +static bool +gate_split_functions (void) +{ + return (flag_partial_inlining + && !profile_arc_flag && !flag_branch_probabilities); +} + +struct gimple_opt_pass pass_split_functions = +{ + { + GIMPLE_PASS, + "fnsplit", /* name */ + gate_split_functions, /* gate */ + execute_split_functions, /* execute */ + NULL, /* sub */ + NULL, /* next */ + 0, /* static_pass_number */ + TV_IPA_FNSPLIT, /* tv_id */ + PROP_cfg, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + TODO_dump_func /* todo_flags_finish */ + } +}; + +/* Gate feedback driven function splitting pass. + We don't need to split when profiling at all, we are producing + lousy code anyway. */ + +static bool +gate_feedback_split_functions (void) +{ + return (flag_partial_inlining + && flag_branch_probabilities); +} + +/* Execute function splitting pass. */ + +static unsigned int +execute_feedback_split_functions (void) +{ + unsigned int retval = execute_split_functions (); + if (retval) + retval |= TODO_rebuild_cgraph_edges; + return retval; +} + +struct gimple_opt_pass pass_feedback_split_functions = +{ + { + GIMPLE_PASS, + "feedback_fnsplit", /* name */ + gate_feedback_split_functions, /* gate */ + execute_feedback_split_functions, /* execute */ + NULL, /* sub */ + NULL, /* next */ + 0, /* static_pass_number */ + TV_IPA_FNSPLIT, /* tv_id */ + PROP_cfg, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + TODO_dump_func /* todo_flags_finish */ + } +}; -- cgit v1.2.3