/* Build live ranges for pseudos. Copyright (C) 2010-2020 Free Software Foundation, Inc. Contributed by Vladimir Makarov . 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 . */ /* This file contains code to build pseudo live-ranges (analogous structures used in IRA, so read comments about the live-ranges there) and other info necessary for other passes to assign hard-registers to pseudos, coalesce the spilled pseudos, and assign stack memory slots to spilled pseudos. */ #include "config.h" #include "system.h" #include "coretypes.h" #include "backend.h" #include "rtl.h" #include "tree.h" #include "predict.h" #include "df.h" #include "memmodel.h" #include "tm_p.h" #include "insn-config.h" #include "regs.h" #include "ira.h" #include "recog.h" #include "cfganal.h" #include "sparseset.h" #include "lra-int.h" #include "target.h" #include "function-abi.h" /* Program points are enumerated by numbers from range 0..LRA_LIVE_MAX_POINT-1. There are approximately two times more program points than insns. Program points are places in the program where liveness info can be changed. In most general case (there are more complicated cases too) some program points correspond to places where input operand dies and other ones correspond to places where output operands are born. */ int lra_live_max_point; /* Accumulated execution frequency of all references for each hard register. */ int lra_hard_reg_usage[FIRST_PSEUDO_REGISTER]; /* A global flag whose true value says to build live ranges for all pseudos, otherwise the live ranges only for pseudos got memory is build. True value means also building copies and setting up hard register preferences. The complete info is necessary only for the assignment pass. The complete info is not needed for the coalescing and spill passes. */ static bool complete_info_p; /* Pseudos live at current point in the RTL scan. */ static sparseset pseudos_live; /* Pseudos probably living through calls and setjumps. As setjump is a call too, if a bit in PSEUDOS_LIVE_THROUGH_SETJUMPS is set up then the corresponding bit in PSEUDOS_LIVE_THROUGH_CALLS is set up too. These data are necessary for cases when only one subreg of a multi-reg pseudo is set up after a call. So we decide it is probably live when traversing bb backward. We are sure about living when we see its usage or definition of the pseudo. */ static sparseset pseudos_live_through_calls; static sparseset pseudos_live_through_setjumps; /* Set of hard regs (except eliminable ones) currently live. */ static HARD_REG_SET hard_regs_live; /* Set of pseudos and hard registers start living/dying in the current insn. These sets are used to update REG_DEAD and REG_UNUSED notes in the insn. */ static sparseset start_living, start_dying; /* Set of pseudos and hard regs dead and unused in the current insn. */ static sparseset unused_set, dead_set; /* Bitmap used for holding intermediate bitmap operation results. */ static bitmap_head temp_bitmap; /* Pool for pseudo live ranges. */ static object_allocator lra_live_range_pool ("live ranges"); /* Free live range list LR. */ static void free_live_range_list (lra_live_range_t lr) { lra_live_range_t next; while (lr != NULL) { next = lr->next; lra_live_range_pool.remove (lr); lr = next; } } /* Create and return pseudo live range with given attributes. */ static lra_live_range_t create_live_range (int regno, int start, int finish, lra_live_range_t next) { lra_live_range_t p = lra_live_range_pool.allocate (); p->regno = regno; p->start = start; p->finish = finish; p->next = next; return p; } /* Copy live range R and return the result. */ static lra_live_range_t copy_live_range (lra_live_range_t r) { return new (lra_live_range_pool) lra_live_range (*r); } /* Copy live range list given by its head R and return the result. */ lra_live_range_t lra_copy_live_range_list (lra_live_range_t r) { lra_live_range_t p, first, *chain; first = NULL; for (chain = &first; r != NULL; r = r->next) { p = copy_live_range (r); *chain = p; chain = &p->next; } return first; } /* Merge *non-intersected* ranges R1 and R2 and returns the result. The function maintains the order of ranges and tries to minimize size of the result range list. Ranges R1 and R2 may not be used after the call. */ lra_live_range_t lra_merge_live_ranges (lra_live_range_t r1, lra_live_range_t r2) { lra_live_range_t first, last; if (r1 == NULL) return r2; if (r2 == NULL) return r1; for (first = last = NULL; r1 != NULL && r2 != NULL;) { if (r1->start < r2->start) std::swap (r1, r2); if (r1->start == r2->finish + 1) { /* Joint ranges: merge r1 and r2 into r1. */ r1->start = r2->start; lra_live_range_t temp = r2; r2 = r2->next; lra_live_range_pool.remove (temp); } else { gcc_assert (r2->finish + 1 < r1->start); /* Add r1 to the result. */ if (first == NULL) first = last = r1; else { last->next = r1; last = r1; } r1 = r1->next; } } if (r1 != NULL) { if (first == NULL) first = r1; else last->next = r1; } else { lra_assert (r2 != NULL); if (first == NULL) first = r2; else last->next = r2; } return first; } /* Return TRUE if live ranges R1 and R2 intersect. */ bool lra_intersected_live_ranges_p (lra_live_range_t r1, lra_live_range_t r2) { /* Remember the live ranges are always kept ordered. */ while (r1 != NULL && r2 != NULL) { if (r1->start > r2->finish) r1 = r1->next; else if (r2->start > r1->finish) r2 = r2->next; else return true; } return false; } enum point_type { DEF_POINT, USE_POINT }; /* Return TRUE if set A contains a pseudo register, otherwise, return FALSE. */ static bool sparseset_contains_pseudos_p (sparseset a) { int regno; EXECUTE_IF_SET_IN_SPARSESET (a, regno) if (!HARD_REGISTER_NUM_P (regno)) return true; return false; } /* Mark pseudo REGNO as living or dying at program point POINT, depending on whether TYPE is a definition or a use. If this is the first reference to REGNO that we've encountered, then create a new live range for it. */ static void update_pseudo_point (int regno, int point, enum point_type type) { lra_live_range_t p; /* Don't compute points for hard registers. */ if (HARD_REGISTER_NUM_P (regno)) return; if (complete_info_p || lra_get_regno_hard_regno (regno) < 0) { if (type == DEF_POINT) { if (sparseset_bit_p (pseudos_live, regno)) { p = lra_reg_info[regno].live_ranges; lra_assert (p != NULL); p->finish = point; } } else /* USE_POINT */ { if (!sparseset_bit_p (pseudos_live, regno) && ((p = lra_reg_info[regno].live_ranges) == NULL || (p->finish != point && p->finish + 1 != point))) lra_reg_info[regno].live_ranges = create_live_range (regno, point, -1, p); } } } /* The corresponding bitmaps of BB currently being processed. */ static bitmap bb_killed_pseudos, bb_gen_pseudos; /* Record hard register REGNO as now being live. It updates living hard regs and START_LIVING. */ static void make_hard_regno_live (int regno) { lra_assert (HARD_REGISTER_NUM_P (regno)); if (TEST_HARD_REG_BIT (hard_regs_live, regno) || TEST_HARD_REG_BIT (eliminable_regset, regno)) return; SET_HARD_REG_BIT (hard_regs_live, regno); sparseset_set_bit (start_living, regno); if (fixed_regs[regno] || TEST_HARD_REG_BIT (hard_regs_spilled_into, regno)) bitmap_set_bit (bb_gen_pseudos, regno); } /* Process the definition of hard register REGNO. This updates hard_regs_live, START_DYING and conflict hard regs for living pseudos. */ static void make_hard_regno_dead (int regno) { if (TEST_HARD_REG_BIT (eliminable_regset, regno)) return; lra_assert (HARD_REGISTER_NUM_P (regno)); unsigned int i; EXECUTE_IF_SET_IN_SPARSESET (pseudos_live, i) SET_HARD_REG_BIT (lra_reg_info[i].conflict_hard_regs, regno); if (! TEST_HARD_REG_BIT (hard_regs_live, regno)) return; CLEAR_HARD_REG_BIT (hard_regs_live, regno); sparseset_set_bit (start_dying, regno); if (fixed_regs[regno] || TEST_HARD_REG_BIT (hard_regs_spilled_into, regno)) { bitmap_clear_bit (bb_gen_pseudos, regno); bitmap_set_bit (bb_killed_pseudos, regno); } } /* Mark pseudo REGNO as now being live and update START_LIVING. */ static void mark_pseudo_live (int regno) { lra_assert (!HARD_REGISTER_NUM_P (regno)); if (sparseset_bit_p (pseudos_live, regno)) return; sparseset_set_bit (pseudos_live, regno); sparseset_set_bit (start_living, regno); } /* Mark pseudo REGNO as now being dead and update START_DYING. */ static void mark_pseudo_dead (int regno) { lra_assert (!HARD_REGISTER_NUM_P (regno)); lra_reg_info[regno].conflict_hard_regs |= hard_regs_live; if (!sparseset_bit_p (pseudos_live, regno)) return; sparseset_clear_bit (pseudos_live, regno); sparseset_set_bit (start_dying, regno); } /* Mark register REGNO (pseudo or hard register) in MODE as being live and update BB_GEN_PSEUDOS. */ static void mark_regno_live (int regno, machine_mode mode) { int last; if (HARD_REGISTER_NUM_P (regno)) { for (last = end_hard_regno (mode, regno); regno < last; regno++) make_hard_regno_live (regno); } else { mark_pseudo_live (regno); bitmap_set_bit (bb_gen_pseudos, regno); } } /* Mark register REGNO (pseudo or hard register) in MODE as being dead and update BB_GEN_PSEUDOS and BB_KILLED_PSEUDOS. */ static void mark_regno_dead (int regno, machine_mode mode) { int last; if (HARD_REGISTER_NUM_P (regno)) { for (last = end_hard_regno (mode, regno); regno < last; regno++) make_hard_regno_dead (regno); } else { mark_pseudo_dead (regno); bitmap_clear_bit (bb_gen_pseudos, regno); bitmap_set_bit (bb_killed_pseudos, regno); } } /* This page contains code for making global live analysis of pseudos. The code works only when pseudo live info is changed on a BB border. That might be a consequence of some global transformations in LRA, e.g. PIC pseudo reuse or rematerialization. */ /* Structure describing local BB data used for pseudo live-analysis. */ class bb_data_pseudos { public: /* Basic block about which the below data are. */ basic_block bb; bitmap_head killed_pseudos; /* pseudos killed in the BB. */ bitmap_head gen_pseudos; /* pseudos generated in the BB. */ }; /* Array for all BB data. Indexed by the corresponding BB index. */ typedef class bb_data_pseudos *bb_data_t; /* All basic block data are referred through the following array. */ static bb_data_t bb_data; /* Two small functions for access to the bb data. */ static inline bb_data_t get_bb_data (basic_block bb) { return &bb_data[(bb)->index]; } static inline bb_data_t get_bb_data_by_index (int index) { return &bb_data[index]; } /* Bitmap with all hard regs. */ static bitmap_head all_hard_regs_bitmap; /* The transfer function used by the DF equation solver to propagate live info through block with BB_INDEX according to the following equation: bb.livein = (bb.liveout - bb.kill) OR bb.gen */ static bool live_trans_fun (int bb_index) { basic_block bb = get_bb_data_by_index (bb_index)->bb; bitmap bb_liveout = df_get_live_out (bb); bitmap bb_livein = df_get_live_in (bb); bb_data_t bb_info = get_bb_data (bb); bitmap_and_compl (&temp_bitmap, bb_liveout, &all_hard_regs_bitmap); return bitmap_ior_and_compl (bb_livein, &bb_info->gen_pseudos, &temp_bitmap, &bb_info->killed_pseudos); } /* The confluence function used by the DF equation solver to set up live info for a block BB without predecessor. */ static void live_con_fun_0 (basic_block bb) { bitmap_and_into (df_get_live_out (bb), &all_hard_regs_bitmap); } /* The confluence function used by the DF equation solver to propagate live info from successor to predecessor on edge E according to the following equation: bb.liveout = 0 for entry block | OR (livein of successors) */ static bool live_con_fun_n (edge e) { basic_block bb = e->src; basic_block dest = e->dest; bitmap bb_liveout = df_get_live_out (bb); bitmap dest_livein = df_get_live_in (dest); return bitmap_ior_and_compl_into (bb_liveout, dest_livein, &all_hard_regs_bitmap); } /* Indexes of all function blocks. */ static bitmap_head all_blocks; /* Allocate and initialize data needed for global pseudo live analysis. */ static void initiate_live_solver (void) { bitmap_initialize (&all_hard_regs_bitmap, ®_obstack); bitmap_set_range (&all_hard_regs_bitmap, 0, FIRST_PSEUDO_REGISTER); bb_data = XNEWVEC (class bb_data_pseudos, last_basic_block_for_fn (cfun)); bitmap_initialize (&all_blocks, ®_obstack); basic_block bb; FOR_ALL_BB_FN (bb, cfun) { bb_data_t bb_info = get_bb_data (bb); bb_info->bb = bb; bitmap_initialize (&bb_info->killed_pseudos, ®_obstack); bitmap_initialize (&bb_info->gen_pseudos, ®_obstack); bitmap_set_bit (&all_blocks, bb->index); } } /* Free all data needed for global pseudo live analysis. */ static void finish_live_solver (void) { basic_block bb; bitmap_clear (&all_blocks); FOR_ALL_BB_FN (bb, cfun) { bb_data_t bb_info = get_bb_data (bb); bitmap_clear (&bb_info->killed_pseudos); bitmap_clear (&bb_info->gen_pseudos); } free (bb_data); bitmap_clear (&all_hard_regs_bitmap); } /* Insn currently scanned. */ static rtx_insn *curr_insn; /* The insn data. */ static lra_insn_recog_data_t curr_id; /* The insn static data. */ static struct lra_static_insn_data *curr_static_id; /* Vec containing execution frequencies of program points. */ static vec point_freq_vec; /* The start of the above vector elements. */ int *lra_point_freq; /* Increment the current program point POINT to the next point which has execution frequency FREQ. */ static void next_program_point (int &point, int freq) { point_freq_vec.safe_push (freq); lra_point_freq = point_freq_vec.address (); point++; } /* Update the preference of HARD_REGNO for pseudo REGNO by PROFIT. */ void lra_setup_reload_pseudo_preferenced_hard_reg (int regno, int hard_regno, int profit) { lra_assert (regno >= lra_constraint_new_regno_start); if (lra_reg_info[regno].preferred_hard_regno1 == hard_regno) lra_reg_info[regno].preferred_hard_regno_profit1 += profit; else if (lra_reg_info[regno].preferred_hard_regno2 == hard_regno) lra_reg_info[regno].preferred_hard_regno_profit2 += profit; else if (lra_reg_info[regno].preferred_hard_regno1 < 0) { lra_reg_info[regno].preferred_hard_regno1 = hard_regno; lra_reg_info[regno].preferred_hard_regno_profit1 = profit; } else if (lra_reg_info[regno].preferred_hard_regno2 < 0 || profit > lra_reg_info[regno].preferred_hard_regno_profit2) { lra_reg_info[regno].preferred_hard_regno2 = hard_regno; lra_reg_info[regno].preferred_hard_regno_profit2 = profit; } else return; /* Keep the 1st hard regno as more profitable. */ if (lra_reg_info[regno].preferred_hard_regno1 >= 0 && lra_reg_info[regno].preferred_hard_regno2 >= 0 && (lra_reg_info[regno].preferred_hard_regno_profit2 > lra_reg_info[regno].preferred_hard_regno_profit1)) { std::swap (lra_reg_info[regno].preferred_hard_regno1, lra_reg_info[regno].preferred_hard_regno2); std::swap (lra_reg_info[regno].preferred_hard_regno_profit1, lra_reg_info[regno].preferred_hard_regno_profit2); } if (lra_dump_file != NULL) { if ((hard_regno = lra_reg_info[regno].preferred_hard_regno1) >= 0) fprintf (lra_dump_file, " Hard reg %d is preferable by r%d with profit %d\n", hard_regno, regno, lra_reg_info[regno].preferred_hard_regno_profit1); if ((hard_regno = lra_reg_info[regno].preferred_hard_regno2) >= 0) fprintf (lra_dump_file, " Hard reg %d is preferable by r%d with profit %d\n", hard_regno, regno, lra_reg_info[regno].preferred_hard_regno_profit2); } } /* Check whether REGNO lives through calls and setjmps and clear the corresponding bits in PSEUDOS_LIVE_THROUGH_CALLS and PSEUDOS_LIVE_THROUGH_SETJUMPS. All calls in the region described by PSEUDOS_LIVE_THROUGH_CALLS have the given ABI. */ static inline void check_pseudos_live_through_calls (int regno, const function_abi &abi) { if (! sparseset_bit_p (pseudos_live_through_calls, regno)) return; machine_mode mode = PSEUDO_REGNO_MODE (regno); sparseset_clear_bit (pseudos_live_through_calls, regno); lra_reg_info[regno].conflict_hard_regs |= abi.mode_clobbers (mode); if (! sparseset_bit_p (pseudos_live_through_setjumps, regno)) return; sparseset_clear_bit (pseudos_live_through_setjumps, regno); /* Don't allocate pseudos that cross setjmps or any call, if this function receives a nonlocal goto. */ SET_HARD_REG_SET (lra_reg_info[regno].conflict_hard_regs); } /* Return true if insn REG is an early clobber operand in alternative NALT. Negative NALT means that we don't know the current insn alternative. So assume the worst. */ static inline bool reg_early_clobber_p (const struct lra_insn_reg *reg, int n_alt) { return (n_alt == LRA_UNKNOWN_ALT ? reg->early_clobber_alts != 0 : (n_alt != LRA_NON_CLOBBERED_ALT && TEST_BIT (reg->early_clobber_alts, n_alt))); } /* Process insns of the basic block BB to update pseudo live ranges, pseudo hard register conflicts, and insn notes. We do it on backward scan of BB insns. CURR_POINT is the program point where BB ends. The function updates this counter and returns in CURR_POINT the program point where BB starts. The function also does local live info updates and can delete the dead insns if DEAD_INSN_P. It returns true if pseudo live info was changed at the BB start. */ static bool process_bb_lives (basic_block bb, int &curr_point, bool dead_insn_p) { int i, regno, freq; unsigned int j; bitmap_iterator bi; bitmap reg_live_out; unsigned int px; rtx_insn *next; rtx link, *link_loc; bool need_curr_point_incr; /* Only has a meaningful value once we've seen a call. */ function_abi last_call_abi = default_function_abi; reg_live_out = df_get_live_out (bb); sparseset_clear (pseudos_live); sparseset_clear (pseudos_live_through_calls); sparseset_clear (pseudos_live_through_setjumps); REG_SET_TO_HARD_REG_SET (hard_regs_live, reg_live_out); hard_regs_live &= ~eliminable_regset; EXECUTE_IF_SET_IN_BITMAP (reg_live_out, FIRST_PSEUDO_REGISTER, j, bi) { update_pseudo_point (j, curr_point, USE_POINT); mark_pseudo_live (j); } bb_gen_pseudos = &get_bb_data (bb)->gen_pseudos; bb_killed_pseudos = &get_bb_data (bb)->killed_pseudos; bitmap_clear (bb_gen_pseudos); bitmap_clear (bb_killed_pseudos); freq = REG_FREQ_FROM_BB (bb); if (lra_dump_file != NULL) fprintf (lra_dump_file, " BB %d\n", bb->index); /* Scan the code of this basic block, noting which pseudos and hard regs are born or die. Note that this loop treats uninitialized values as live until the beginning of the block. For example, if an instruction uses (reg:DI foo), and only (subreg:SI (reg:DI foo) 0) is ever set, FOO will remain live until the beginning of the block. Likewise if FOO is not set at all. This is unnecessarily pessimistic, but it probably doesn't matter much in practice. */ FOR_BB_INSNS_REVERSE_SAFE (bb, curr_insn, next) { bool call_p; int n_alt, dst_regno, src_regno; rtx set; struct lra_insn_reg *reg; if (!NONDEBUG_INSN_P (curr_insn)) continue; curr_id = lra_get_insn_recog_data (curr_insn); curr_static_id = curr_id->insn_static_data; n_alt = curr_id->used_insn_alternative; if (lra_dump_file != NULL) fprintf (lra_dump_file, " Insn %u: point = %d, n_alt = %d\n", INSN_UID (curr_insn), curr_point, n_alt); set = single_set (curr_insn); if (dead_insn_p && set != NULL_RTX && REG_P (SET_DEST (set)) && !HARD_REGISTER_P (SET_DEST (set)) && find_reg_note (curr_insn, REG_EH_REGION, NULL_RTX) == NULL_RTX && ! may_trap_p (PATTERN (curr_insn)) /* Don't do premature remove of pic offset pseudo as we can start to use it after some reload generation. */ && (pic_offset_table_rtx == NULL_RTX || pic_offset_table_rtx != SET_DEST (set))) { bool remove_p = true; for (reg = curr_id->regs; reg != NULL; reg = reg->next) if (reg->type != OP_IN && sparseset_bit_p (pseudos_live, reg->regno)) { remove_p = false; break; } for (reg = curr_static_id->hard_regs; reg != NULL; reg = reg->next) if (reg->type != OP_IN) { remove_p = false; break; } if (remove_p && ! volatile_refs_p (PATTERN (curr_insn))) { dst_regno = REGNO (SET_DEST (set)); if (lra_dump_file != NULL) fprintf (lra_dump_file, " Deleting dead insn %u\n", INSN_UID (curr_insn)); lra_set_insn_deleted (curr_insn); if (lra_reg_info[dst_regno].nrefs == 0) { /* There might be some debug insns with the pseudo. */ unsigned int uid; rtx_insn *insn; bitmap_copy (&temp_bitmap, &lra_reg_info[dst_regno].insn_bitmap); EXECUTE_IF_SET_IN_BITMAP (&temp_bitmap, 0, uid, bi) { insn = lra_insn_recog_data[uid]->insn; lra_substitute_pseudo_within_insn (insn, dst_regno, SET_SRC (set), true); lra_update_insn_regno_info (insn); } } continue; } } /* Update max ref width and hard reg usage. */ for (reg = curr_id->regs; reg != NULL; reg = reg->next) { int i, regno = reg->regno; if (partial_subreg_p (lra_reg_info[regno].biggest_mode, reg->biggest_mode)) lra_reg_info[regno].biggest_mode = reg->biggest_mode; if (HARD_REGISTER_NUM_P (regno)) { lra_hard_reg_usage[regno] += freq; /* A hard register explicitly can be used in small mode, but implicitly it can be used in natural mode as a part of multi-register group. Process this case here. */ for (i = 1; i < hard_regno_nregs (regno, reg->biggest_mode); i++) if (partial_subreg_p (lra_reg_info[regno + i].biggest_mode, GET_MODE (regno_reg_rtx[regno + i]))) lra_reg_info[regno + i].biggest_mode = GET_MODE (regno_reg_rtx[regno + i]); } } call_p = CALL_P (curr_insn); /* If we have a simple register copy and the source reg is live after this instruction, then remove the source reg from the live set so that it will not conflict with the destination reg. */ rtx ignore_reg = non_conflicting_reg_copy_p (curr_insn); if (ignore_reg != NULL_RTX) { int ignore_regno = REGNO (ignore_reg); if (HARD_REGISTER_NUM_P (ignore_regno) && TEST_HARD_REG_BIT (hard_regs_live, ignore_regno)) CLEAR_HARD_REG_BIT (hard_regs_live, ignore_regno); else if (!HARD_REGISTER_NUM_P (ignore_regno) && sparseset_bit_p (pseudos_live, ignore_regno)) sparseset_clear_bit (pseudos_live, ignore_regno); else /* We don't need any special handling of the source reg if it is dead after this instruction. */ ignore_reg = NULL_RTX; } src_regno = (set != NULL_RTX && REG_P (SET_SRC (set)) ? REGNO (SET_SRC (set)) : -1); dst_regno = (set != NULL_RTX && REG_P (SET_DEST (set)) ? REGNO (SET_DEST (set)) : -1); if (complete_info_p && src_regno >= 0 && dst_regno >= 0 /* Check that source regno does not conflict with destination regno to exclude most impossible preferences. */ && (((!HARD_REGISTER_NUM_P (src_regno) && (! sparseset_bit_p (pseudos_live, src_regno) || (!HARD_REGISTER_NUM_P (dst_regno) && lra_reg_val_equal_p (src_regno, lra_reg_info[dst_regno].val, lra_reg_info[dst_regno].offset)))) || (HARD_REGISTER_NUM_P (src_regno) && ! TEST_HARD_REG_BIT (hard_regs_live, src_regno))) /* It might be 'inheritance pseudo <- reload pseudo'. */ || (src_regno >= lra_constraint_new_regno_start && dst_regno >= lra_constraint_new_regno_start /* Remember to skip special cases where src/dest regnos are the same, e.g. insn SET pattern has matching constraints like =r,0. */ && src_regno != dst_regno))) { int hard_regno = -1, regno = -1; if (dst_regno >= lra_constraint_new_regno_start && src_regno >= lra_constraint_new_regno_start) { /* It might be still an original (non-reload) insn with one unused output and a constraint requiring to use the same reg for input/output operands. In this case dst_regno and src_regno have the same value, we don't need a misleading copy for this case. */ if (dst_regno != src_regno) lra_create_copy (dst_regno, src_regno, freq); } else if (dst_regno >= lra_constraint_new_regno_start) { if (!HARD_REGISTER_NUM_P (hard_regno = src_regno)) hard_regno = reg_renumber[src_regno]; regno = dst_regno; } else if (src_regno >= lra_constraint_new_regno_start) { if (!HARD_REGISTER_NUM_P (hard_regno = dst_regno)) hard_regno = reg_renumber[dst_regno]; regno = src_regno; } if (regno >= 0 && hard_regno >= 0) lra_setup_reload_pseudo_preferenced_hard_reg (regno, hard_regno, freq); } sparseset_clear (start_living); /* Mark each defined value as live. We need to do this for unused values because they still conflict with quantities that are live at the time of the definition. */ for (reg = curr_id->regs; reg != NULL; reg = reg->next) if (reg->type != OP_IN) { update_pseudo_point (reg->regno, curr_point, USE_POINT); mark_regno_live (reg->regno, reg->biggest_mode); /* ??? Should be a no-op for unused registers. */ check_pseudos_live_through_calls (reg->regno, last_call_abi); } for (reg = curr_static_id->hard_regs; reg != NULL; reg = reg->next) if (reg->type != OP_IN) make_hard_regno_live (reg->regno); if (curr_id->arg_hard_regs != NULL) for (i = 0; (regno = curr_id->arg_hard_regs[i]) >= 0; i++) if (!HARD_REGISTER_NUM_P (regno)) /* It is a clobber. */ make_hard_regno_live (regno - FIRST_PSEUDO_REGISTER); sparseset_copy (unused_set, start_living); sparseset_clear (start_dying); /* See which defined values die here. */ for (reg = curr_id->regs; reg != NULL; reg = reg->next) if (reg->type != OP_IN && ! reg_early_clobber_p (reg, n_alt) && ! reg->subreg_p) { if (reg->type == OP_OUT) update_pseudo_point (reg->regno, curr_point, DEF_POINT); mark_regno_dead (reg->regno, reg->biggest_mode); } for (reg = curr_static_id->hard_regs; reg != NULL; reg = reg->next) if (reg->type != OP_IN && ! reg_early_clobber_p (reg, n_alt) && ! reg->subreg_p) make_hard_regno_dead (reg->regno); if (curr_id->arg_hard_regs != NULL) for (i = 0; (regno = curr_id->arg_hard_regs[i]) >= 0; i++) if (!HARD_REGISTER_NUM_P (regno)) /* It is a clobber. */ make_hard_regno_dead (regno - FIRST_PSEUDO_REGISTER); if (call_p) { function_abi call_abi = insn_callee_abi (curr_insn); if (last_call_abi != call_abi) EXECUTE_IF_SET_IN_SPARSESET (pseudos_live, j) check_pseudos_live_through_calls (j, last_call_abi); last_call_abi = call_abi; sparseset_ior (pseudos_live_through_calls, pseudos_live_through_calls, pseudos_live); if (cfun->has_nonlocal_label || (!targetm.setjmp_preserves_nonvolatile_regs_p () && (find_reg_note (curr_insn, REG_SETJMP, NULL_RTX) != NULL_RTX))) sparseset_ior (pseudos_live_through_setjumps, pseudos_live_through_setjumps, pseudos_live); } /* Increment the current program point if we must. */ if (sparseset_contains_pseudos_p (unused_set) || sparseset_contains_pseudos_p (start_dying)) next_program_point (curr_point, freq); /* If we removed the source reg from a simple register copy from the live set above, then add it back now so we don't accidentally add it to the start_living set below. */ if (ignore_reg != NULL_RTX) { int ignore_regno = REGNO (ignore_reg); if (HARD_REGISTER_NUM_P (ignore_regno)) SET_HARD_REG_BIT (hard_regs_live, ignore_regno); else sparseset_set_bit (pseudos_live, ignore_regno); } sparseset_clear (start_living); /* Mark each used value as live. */ for (reg = curr_id->regs; reg != NULL; reg = reg->next) if (reg->type != OP_OUT) { if (reg->type == OP_IN) update_pseudo_point (reg->regno, curr_point, USE_POINT); mark_regno_live (reg->regno, reg->biggest_mode); check_pseudos_live_through_calls (reg->regno, last_call_abi); } for (reg = curr_static_id->hard_regs; reg != NULL; reg = reg->next) if (reg->type != OP_OUT) make_hard_regno_live (reg->regno); if (curr_id->arg_hard_regs != NULL) /* Make argument hard registers live. */ for (i = 0; (regno = curr_id->arg_hard_regs[i]) >= 0; i++) if (HARD_REGISTER_NUM_P (regno)) make_hard_regno_live (regno); sparseset_and_compl (dead_set, start_living, start_dying); sparseset_clear (start_dying); /* Mark early clobber outputs dead. */ for (reg = curr_id->regs; reg != NULL; reg = reg->next) if (reg->type != OP_IN && reg_early_clobber_p (reg, n_alt) && ! reg->subreg_p) { if (reg->type == OP_OUT) update_pseudo_point (reg->regno, curr_point, DEF_POINT); mark_regno_dead (reg->regno, reg->biggest_mode); /* We're done processing inputs, so make sure early clobber operands that are both inputs and outputs are still live. */ if (reg->type == OP_INOUT) mark_regno_live (reg->regno, reg->biggest_mode); } for (reg = curr_static_id->hard_regs; reg != NULL; reg = reg->next) if (reg->type != OP_IN && reg_early_clobber_p (reg, n_alt) && ! reg->subreg_p) { struct lra_insn_reg *reg2; /* We can have early clobbered non-operand hard reg and the same hard reg as an insn input. Don't make hard reg dead before the insns. */ for (reg2 = curr_id->regs; reg2 != NULL; reg2 = reg2->next) if (reg2->type != OP_OUT && reg2->regno == reg->regno) break; if (reg2 == NULL) make_hard_regno_dead (reg->regno); } /* Increment the current program point if we must. */ if (sparseset_contains_pseudos_p (dead_set) || sparseset_contains_pseudos_p (start_dying)) next_program_point (curr_point, freq); /* Update notes. */ for (link_loc = ®_NOTES (curr_insn); (link = *link_loc) != NULL_RTX;) { if (REG_NOTE_KIND (link) != REG_DEAD && REG_NOTE_KIND (link) != REG_UNUSED) ; else if (REG_P (XEXP (link, 0))) { regno = REGNO (XEXP (link, 0)); if ((REG_NOTE_KIND (link) == REG_DEAD && ! sparseset_bit_p (dead_set, regno)) || (REG_NOTE_KIND (link) == REG_UNUSED && ! sparseset_bit_p (unused_set, regno))) { *link_loc = XEXP (link, 1); continue; } if (REG_NOTE_KIND (link) == REG_DEAD) sparseset_clear_bit (dead_set, regno); else if (REG_NOTE_KIND (link) == REG_UNUSED) sparseset_clear_bit (unused_set, regno); } link_loc = &XEXP (link, 1); } EXECUTE_IF_SET_IN_SPARSESET (dead_set, j) add_reg_note (curr_insn, REG_DEAD, regno_reg_rtx[j]); EXECUTE_IF_SET_IN_SPARSESET (unused_set, j) add_reg_note (curr_insn, REG_UNUSED, regno_reg_rtx[j]); } if (bb_has_eh_pred (bb)) /* Any pseudos that are currently live conflict with the eh_return data registers. For liveness purposes, these registers are set by artificial definitions at the start of the BB, so are not actually live on entry. */ for (j = 0; ; ++j) { unsigned int regno = EH_RETURN_DATA_REGNO (j); if (regno == INVALID_REGNUM) break; make_hard_regno_live (regno); make_hard_regno_dead (regno); } /* Pseudos can't go in stack regs at the start of a basic block that is reached by an abnormal edge. Likewise for registers that are at least partly call clobbered, because caller-save, fixup_abnormal_edges and possibly the table driven EH machinery are not quite ready to handle such pseudos live across such edges. */ if (bb_has_abnormal_pred (bb)) { HARD_REG_SET clobbers; CLEAR_HARD_REG_SET (clobbers); #ifdef STACK_REGS EXECUTE_IF_SET_IN_SPARSESET (pseudos_live, px) lra_reg_info[px].no_stack_p = true; for (px = FIRST_STACK_REG; px <= LAST_STACK_REG; px++) SET_HARD_REG_BIT (clobbers, px); #endif /* No need to record conflicts for call clobbered regs if we have nonlocal labels around, as we don't ever try to allocate such regs in this case. */ if (!cfun->has_nonlocal_label && has_abnormal_call_or_eh_pred_edge_p (bb)) for (px = 0; HARD_REGISTER_NUM_P (px); px++) if (eh_edge_abi.clobbers_at_least_part_of_reg_p (px) #ifdef REAL_PIC_OFFSET_TABLE_REGNUM /* We should create a conflict of PIC pseudo with PIC hard reg as PIC hard reg can have a wrong value after jump described by the abnormal edge. In this case we cannot allocate PIC hard reg to PIC pseudo as PIC pseudo will also have a wrong value. */ || (px == REAL_PIC_OFFSET_TABLE_REGNUM && pic_offset_table_rtx != NULL_RTX && !HARD_REGISTER_P (pic_offset_table_rtx)) #endif ) SET_HARD_REG_BIT (clobbers, px); clobbers &= ~hard_regs_live; for (px = 0; HARD_REGISTER_NUM_P (px); px++) if (TEST_HARD_REG_BIT (clobbers, px)) { make_hard_regno_live (px); make_hard_regno_dead (px); } } bool live_change_p = false; /* Check if bb border live info was changed. */ unsigned int live_pseudos_num = 0; EXECUTE_IF_SET_IN_BITMAP (df_get_live_in (bb), FIRST_PSEUDO_REGISTER, j, bi) { live_pseudos_num++; if (! sparseset_bit_p (pseudos_live, j)) { live_change_p = true; if (lra_dump_file != NULL) fprintf (lra_dump_file, " r%d is removed as live at bb%d start\n", j, bb->index); break; } } if (! live_change_p && sparseset_cardinality (pseudos_live) != live_pseudos_num) { live_change_p = true; if (lra_dump_file != NULL) EXECUTE_IF_SET_IN_SPARSESET (pseudos_live, j) if (! bitmap_bit_p (df_get_live_in (bb), j)) fprintf (lra_dump_file, " r%d is added to live at bb%d start\n", j, bb->index); } /* See if we'll need an increment at the end of this basic block. An increment is needed if the PSEUDOS_LIVE set is not empty, to make sure the finish points are set up correctly. */ need_curr_point_incr = (sparseset_cardinality (pseudos_live) > 0); EXECUTE_IF_SET_IN_SPARSESET (pseudos_live, i) { update_pseudo_point (i, curr_point, DEF_POINT); mark_pseudo_dead (i); } EXECUTE_IF_SET_IN_BITMAP (df_get_live_in (bb), FIRST_PSEUDO_REGISTER, j, bi) { if (sparseset_cardinality (pseudos_live_through_calls) == 0) break; if (sparseset_bit_p (pseudos_live_through_calls, j)) check_pseudos_live_through_calls (j, last_call_abi); } for (i = 0; HARD_REGISTER_NUM_P (i); ++i) { if (!TEST_HARD_REG_BIT (hard_regs_live, i)) continue; if (!TEST_HARD_REG_BIT (hard_regs_spilled_into, i)) continue; if (bitmap_bit_p (df_get_live_in (bb), i)) continue; live_change_p = true; if (lra_dump_file) fprintf (lra_dump_file, " hard reg r%d is added to live at bb%d start\n", i, bb->index); bitmap_set_bit (df_get_live_in (bb), i); } if (need_curr_point_incr) next_program_point (curr_point, freq); return live_change_p; } /* Compress pseudo live ranges by removing program points where nothing happens. Complexity of many algorithms in LRA is linear function of program points number. To speed up the code we try to minimize the number of the program points here. */ static void remove_some_program_points_and_update_live_ranges (void) { unsigned i; int n, max_regno; int *map; lra_live_range_t r, prev_r, next_r; sbitmap_iterator sbi; bool born_p, dead_p, prev_born_p, prev_dead_p; auto_sbitmap born (lra_live_max_point); auto_sbitmap dead (lra_live_max_point); bitmap_clear (born); bitmap_clear (dead); max_regno = max_reg_num (); for (i = FIRST_PSEUDO_REGISTER; i < (unsigned) max_regno; i++) { for (r = lra_reg_info[i].live_ranges; r != NULL; r = r->next) { lra_assert (r->start <= r->finish); bitmap_set_bit (born, r->start); bitmap_set_bit (dead, r->finish); } } auto_sbitmap born_or_dead (lra_live_max_point); bitmap_ior (born_or_dead, born, dead); map = XCNEWVEC (int, lra_live_max_point); n = -1; prev_born_p = prev_dead_p = false; EXECUTE_IF_SET_IN_BITMAP (born_or_dead, 0, i, sbi) { born_p = bitmap_bit_p (born, i); dead_p = bitmap_bit_p (dead, i); if ((prev_born_p && ! prev_dead_p && born_p && ! dead_p) || (prev_dead_p && ! prev_born_p && dead_p && ! born_p)) { map[i] = n; lra_point_freq[n] = MAX (lra_point_freq[n], lra_point_freq[i]); } else { map[i] = ++n; lra_point_freq[n] = lra_point_freq[i]; } prev_born_p = born_p; prev_dead_p = dead_p; } n++; if (lra_dump_file != NULL) fprintf (lra_dump_file, "Compressing live ranges: from %d to %d - %d%%\n", lra_live_max_point, n, lra_live_max_point ? 100 * n / lra_live_max_point : 100); if (n < lra_live_max_point) { lra_live_max_point = n; for (i = FIRST_PSEUDO_REGISTER; i < (unsigned) max_regno; i++) { for (prev_r = NULL, r = lra_reg_info[i].live_ranges; r != NULL; r = next_r) { next_r = r->next; r->start = map[r->start]; r->finish = map[r->finish]; if (prev_r == NULL || prev_r->start > r->finish + 1) { prev_r = r; continue; } prev_r->start = r->start; prev_r->next = next_r; lra_live_range_pool.remove (r); } } } free (map); } /* Print live ranges R to file F. */ void lra_print_live_range_list (FILE *f, lra_live_range_t r) { for (; r != NULL; r = r->next) fprintf (f, " [%d..%d]", r->start, r->finish); fprintf (f, "\n"); } DEBUG_FUNCTION void debug (lra_live_range &ref) { lra_print_live_range_list (stderr, &ref); } DEBUG_FUNCTION void debug (lra_live_range *ptr) { if (ptr) debug (*ptr); else fprintf (stderr, "\n"); } /* Print live ranges R to stderr. */ void lra_debug_live_range_list (lra_live_range_t r) { lra_print_live_range_list (stderr, r); } /* Print live ranges of pseudo REGNO to file F. */ static void print_pseudo_live_ranges (FILE *f, int regno) { if (lra_reg_info[regno].live_ranges == NULL) return; fprintf (f, " r%d:", regno); lra_print_live_range_list (f, lra_reg_info[regno].live_ranges); } /* Print live ranges of pseudo REGNO to stderr. */ void lra_debug_pseudo_live_ranges (int regno) { print_pseudo_live_ranges (stderr, regno); } /* Print live ranges of all pseudos to file F. */ static void print_live_ranges (FILE *f) { int i, max_regno; max_regno = max_reg_num (); for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) print_pseudo_live_ranges (f, i); } /* Print live ranges of all pseudos to stderr. */ void lra_debug_live_ranges (void) { print_live_ranges (stderr); } /* Compress pseudo live ranges. */ static void compress_live_ranges (void) { remove_some_program_points_and_update_live_ranges (); if (lra_dump_file != NULL) { fprintf (lra_dump_file, "Ranges after the compression:\n"); print_live_ranges (lra_dump_file); } } /* The number of the current live range pass. */ int lra_live_range_iter; /* The function creates live ranges only for memory pseudos (or for all ones if ALL_P), set up CONFLICT_HARD_REGS for the pseudos. It also does dead insn elimination if DEAD_INSN_P and global live analysis only for pseudos and only if the pseudo live info was changed on a BB border. Return TRUE if the live info was changed. */ static bool lra_create_live_ranges_1 (bool all_p, bool dead_insn_p) { basic_block bb; int i, hard_regno, max_regno = max_reg_num (); int curr_point; bool bb_live_change_p, have_referenced_pseudos = false; timevar_push (TV_LRA_CREATE_LIVE_RANGES); complete_info_p = all_p; if (lra_dump_file != NULL) fprintf (lra_dump_file, "\n********** Pseudo live ranges #%d: **********\n\n", ++lra_live_range_iter); memset (lra_hard_reg_usage, 0, sizeof (lra_hard_reg_usage)); for (i = 0; i < max_regno; i++) { lra_reg_info[i].live_ranges = NULL; CLEAR_HARD_REG_SET (lra_reg_info[i].conflict_hard_regs); lra_reg_info[i].preferred_hard_regno1 = -1; lra_reg_info[i].preferred_hard_regno2 = -1; lra_reg_info[i].preferred_hard_regno_profit1 = 0; lra_reg_info[i].preferred_hard_regno_profit2 = 0; #ifdef STACK_REGS lra_reg_info[i].no_stack_p = false; #endif /* The biggest mode is already set but its value might be to conservative because of recent transformation. Here in this file we recalculate it again as it costs practically nothing. */ if (!HARD_REGISTER_NUM_P (i) && regno_reg_rtx[i] != NULL_RTX) lra_reg_info[i].biggest_mode = GET_MODE (regno_reg_rtx[i]); else lra_reg_info[i].biggest_mode = VOIDmode; if (!HARD_REGISTER_NUM_P (i) && lra_reg_info[i].nrefs != 0) { if ((hard_regno = reg_renumber[i]) >= 0) lra_hard_reg_usage[hard_regno] += lra_reg_info[i].freq; have_referenced_pseudos = true; } } lra_free_copies (); /* Under some circumstances, we can have functions without pseudo registers. For such functions, lra_live_max_point will be 0, see e.g. PR55604, and there's nothing more to do for us here. */ if (! have_referenced_pseudos) { timevar_pop (TV_LRA_CREATE_LIVE_RANGES); return false; } pseudos_live = sparseset_alloc (max_regno); pseudos_live_through_calls = sparseset_alloc (max_regno); pseudos_live_through_setjumps = sparseset_alloc (max_regno); start_living = sparseset_alloc (max_regno); start_dying = sparseset_alloc (max_regno); dead_set = sparseset_alloc (max_regno); unused_set = sparseset_alloc (max_regno); curr_point = 0; unsigned new_length = get_max_uid () * 2; point_freq_vec.truncate (0); point_freq_vec.reserve_exact (new_length); lra_point_freq = point_freq_vec.address (); auto_vec post_order_rev_cfg; inverted_post_order_compute (&post_order_rev_cfg); lra_assert (post_order_rev_cfg.length () == (unsigned) n_basic_blocks_for_fn (cfun)); bb_live_change_p = false; for (i = post_order_rev_cfg.length () - 1; i >= 0; --i) { bb = BASIC_BLOCK_FOR_FN (cfun, post_order_rev_cfg[i]); if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun) || bb == ENTRY_BLOCK_PTR_FOR_FN (cfun)) continue; if (process_bb_lives (bb, curr_point, dead_insn_p)) bb_live_change_p = true; } if (bb_live_change_p) { /* We need to clear pseudo live info as some pseudos can disappear, e.g. pseudos with used equivalences. */ FOR_EACH_BB_FN (bb, cfun) { bitmap_clear_range (df_get_live_in (bb), FIRST_PSEUDO_REGISTER, max_regno - FIRST_PSEUDO_REGISTER); bitmap_clear_range (df_get_live_out (bb), FIRST_PSEUDO_REGISTER, max_regno - FIRST_PSEUDO_REGISTER); } /* As we did not change CFG since LRA start we can use DF-infrastructure solver to solve live data flow problem. */ for (int i = 0; HARD_REGISTER_NUM_P (i); ++i) { if (TEST_HARD_REG_BIT (hard_regs_spilled_into, i)) bitmap_clear_bit (&all_hard_regs_bitmap, i); } df_simple_dataflow (DF_BACKWARD, NULL, live_con_fun_0, live_con_fun_n, live_trans_fun, &all_blocks, df_get_postorder (DF_BACKWARD), df_get_n_blocks (DF_BACKWARD)); if (lra_dump_file != NULL) { fprintf (lra_dump_file, "Global pseudo live data have been updated:\n"); basic_block bb; FOR_EACH_BB_FN (bb, cfun) { bb_data_t bb_info = get_bb_data (bb); bitmap bb_livein = df_get_live_in (bb); bitmap bb_liveout = df_get_live_out (bb); fprintf (lra_dump_file, "\nBB %d:\n", bb->index); lra_dump_bitmap_with_title (" gen:", &bb_info->gen_pseudos, bb->index); lra_dump_bitmap_with_title (" killed:", &bb_info->killed_pseudos, bb->index); lra_dump_bitmap_with_title (" livein:", bb_livein, bb->index); lra_dump_bitmap_with_title (" liveout:", bb_liveout, bb->index); } } } lra_live_max_point = curr_point; if (lra_dump_file != NULL) print_live_ranges (lra_dump_file); /* Clean up. */ sparseset_free (unused_set); sparseset_free (dead_set); sparseset_free (start_dying); sparseset_free (start_living); sparseset_free (pseudos_live_through_calls); sparseset_free (pseudos_live_through_setjumps); sparseset_free (pseudos_live); compress_live_ranges (); timevar_pop (TV_LRA_CREATE_LIVE_RANGES); return bb_live_change_p; } /* The main entry function creates live-ranges and other live info necessary for the assignment sub-pass. It uses lra_creates_live_ranges_1 -- so read comments for the function. */ void lra_create_live_ranges (bool all_p, bool dead_insn_p) { if (! lra_create_live_ranges_1 (all_p, dead_insn_p)) return; if (lra_dump_file != NULL) fprintf (lra_dump_file, "Live info was changed -- recalculate it\n"); /* Live info was changed on a bb border. It means that some info, e.g. about conflict regs, calls crossed, and live ranges may be wrong. We need this info for allocation. So recalculate it again but without removing dead insns which can change live info again. Repetitive live range calculations are expensive therefore we stop here as we already have correct info although some improvement in rare cases could be possible on this sub-pass if we do dead insn elimination again (still the improvement may happen later). */ lra_clear_live_ranges (); bool res = lra_create_live_ranges_1 (all_p, false); lra_assert (! res); } /* Finish all live ranges. */ void lra_clear_live_ranges (void) { int i; for (i = 0; i < max_reg_num (); i++) free_live_range_list (lra_reg_info[i].live_ranges); point_freq_vec.release (); } /* Initialize live ranges data once per function. */ void lra_live_ranges_init (void) { bitmap_initialize (&temp_bitmap, ®_obstack); initiate_live_solver (); } /* Finish live ranges data once per function. */ void lra_live_ranges_finish (void) { finish_live_solver (); bitmap_clear (&temp_bitmap); lra_live_range_pool.release (); }