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author | Martin Jambor <mjambor@suse.cz> | 2013-11-12 13:53:53 +0100 |
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committer | Martin Jambor <jamborm@gcc.gnu.org> | 2013-11-12 13:53:53 +0100 |
commit | 732dad8f32152ed7cbb2d4cb8ba0fc21f608fe70 (patch) | |
tree | 8204bc7db38fa0de22d6be0af6e5095e7e8aaf5a /gcc/ira.c | |
parent | e4c04ff0e8852321a12bd02c520cdecef5dc2ac7 (diff) | |
download | gcc-732dad8f32152ed7cbb2d4cb8ba0fc21f608fe70.zip gcc-732dad8f32152ed7cbb2d4cb8ba0fc21f608fe70.tar.gz gcc-732dad8f32152ed7cbb2d4cb8ba0fc21f608fe70.tar.bz2 |
re PR rtl-optimization/10474 (shrink wrapping for functions)
2013-11-12 Martin Jambor <mjambor@suse.cz>
PR rtl-optimization/10474
* ira.c (interesting_dest_for_shprep): New function.
(split_live_ranges_for_shrink_wrap): Likewise.
(find_moveable_pseudos): Move calculation of dominance info,
df_analysios and the final anlyses to...
(ira): ...here, call split_live_ranges_for_shrink_wrap.
testsuite/
* gcc.dg/pr10474.c: New testcase.
* gcc.dg/ira-shrinkwrap-prep-1.c: Likewise.
* gcc.dg/ira-shrinkwrap-prep-2.c: Likewise.
From-SVN: r204698
Diffstat (limited to 'gcc/ira.c')
-rw-r--r-- | gcc/ira.c | 216 |
1 files changed, 205 insertions, 11 deletions
@@ -4515,9 +4515,6 @@ find_moveable_pseudos (void) pseudo_replaced_reg.release (); pseudo_replaced_reg.safe_grow_cleared (max_regs); - df_analyze (); - calculate_dominance_info (CDI_DOMINATORS); - i = 0; bitmap_initialize (&live, 0); bitmap_initialize (&used, 0); @@ -4830,14 +4827,196 @@ find_moveable_pseudos (void) free (bb_moveable_reg_sets); last_moveable_pseudo = max_reg_num (); +} - fix_reg_equiv_init (); - expand_reg_info (); - regstat_free_n_sets_and_refs (); - regstat_free_ri (); - regstat_init_n_sets_and_refs (); - regstat_compute_ri (); - free_dominance_info (CDI_DOMINATORS); + +/* If insn is interesting for parameter range-splitting shring-wrapping + preparation, i.e. it is a single set from a hard register to a pseudo, which + is live at CALL_DOM, return the destination. Otherwise return NULL. */ + +static rtx +interesting_dest_for_shprep (rtx insn, basic_block call_dom) +{ + rtx set = single_set (insn); + if (!set) + return NULL; + rtx src = SET_SRC (set); + rtx dest = SET_DEST (set); + if (!REG_P (src) || !HARD_REGISTER_P (src) + || !REG_P (dest) || HARD_REGISTER_P (dest) + || (call_dom && !bitmap_bit_p (df_get_live_in (call_dom), REGNO (dest)))) + return NULL; + return dest; +} + +/* Split live ranges of pseudos that are loaded from hard registers in the + first BB in a BB that dominates all non-sibling call if such a BB can be + found and is not in a loop. Return true if the function has made any + changes. */ + +static bool +split_live_ranges_for_shrink_wrap (void) +{ + basic_block bb, call_dom = NULL; + basic_block first = single_succ (ENTRY_BLOCK_PTR); + rtx insn, last_interesting_insn = NULL; + bitmap_head need_new, reachable; + vec<basic_block> queue; + + if (!flag_shrink_wrap) + return false; + + bitmap_initialize (&need_new, 0); + bitmap_initialize (&reachable, 0); + queue.create (n_basic_blocks); + + FOR_EACH_BB (bb) + FOR_BB_INSNS (bb, insn) + if (CALL_P (insn) && !SIBLING_CALL_P (insn)) + { + if (bb == first) + { + bitmap_clear (&need_new); + bitmap_clear (&reachable); + queue.release (); + return false; + } + + bitmap_set_bit (&need_new, bb->index); + bitmap_set_bit (&reachable, bb->index); + queue.quick_push (bb); + break; + } + + if (queue.is_empty ()) + { + bitmap_clear (&need_new); + bitmap_clear (&reachable); + queue.release (); + return false; + } + + while (!queue.is_empty ()) + { + edge e; + edge_iterator ei; + + bb = queue.pop (); + FOR_EACH_EDGE (e, ei, bb->succs) + if (e->dest != EXIT_BLOCK_PTR + && bitmap_set_bit (&reachable, e->dest->index)) + queue.quick_push (e->dest); + } + queue.release (); + + FOR_BB_INSNS (first, insn) + { + rtx dest = interesting_dest_for_shprep (insn, NULL); + if (!dest) + continue; + + if (DF_REG_DEF_COUNT (REGNO (dest)) > 1) + { + bitmap_clear (&need_new); + bitmap_clear (&reachable); + return false; + } + + for (df_ref use = DF_REG_USE_CHAIN (REGNO(dest)); + use; + use = DF_REF_NEXT_REG (use)) + { + if (NONDEBUG_INSN_P (DF_REF_INSN (use)) + && GET_CODE (DF_REF_REG (use)) == SUBREG) + { + /* This is necessary to avoid hitting an assert at + postreload.c:2294 in libstc++ testcases on x86_64-linux. I'm + not really sure what the probblem actually is there. */ + bitmap_clear (&need_new); + bitmap_clear (&reachable); + return false; + } + + int ubbi = DF_REF_BB (use)->index; + if (bitmap_bit_p (&reachable, ubbi)) + bitmap_set_bit (&need_new, ubbi); + } + last_interesting_insn = insn; + } + + bitmap_clear (&reachable); + if (!last_interesting_insn) + { + bitmap_clear (&need_new); + return false; + } + + call_dom = nearest_common_dominator_for_set (CDI_DOMINATORS, &need_new); + bitmap_clear (&need_new); + if (call_dom == first) + return false; + + loop_optimizer_init (AVOID_CFG_MODIFICATIONS); + while (bb_loop_depth (call_dom) > 0) + call_dom = get_immediate_dominator (CDI_DOMINATORS, call_dom); + loop_optimizer_finalize (); + + if (call_dom == first) + return false; + + calculate_dominance_info (CDI_POST_DOMINATORS); + if (dominated_by_p (CDI_POST_DOMINATORS, first, call_dom)) + { + free_dominance_info (CDI_POST_DOMINATORS); + return false; + } + free_dominance_info (CDI_POST_DOMINATORS); + + if (dump_file) + fprintf (dump_file, "Will split live ranges of parameters at BB %i\n", + call_dom->index); + + bool ret = false; + FOR_BB_INSNS (first, insn) + { + rtx dest = interesting_dest_for_shprep (insn, call_dom); + if (!dest) + continue; + + rtx newreg = NULL_RTX; + df_ref use, next; + for (use = DF_REG_USE_CHAIN (REGNO(dest)); use; use = next) + { + rtx uin = DF_REF_INSN (use); + next = DF_REF_NEXT_REG (use); + + basic_block ubb = BLOCK_FOR_INSN (uin); + if (ubb == call_dom + || dominated_by_p (CDI_DOMINATORS, ubb, call_dom)) + { + if (!newreg) + newreg = ira_create_new_reg (dest); + validate_change (uin, DF_REF_LOC (use), newreg, true); + } + } + + if (newreg) + { + rtx new_move = gen_move_insn (newreg, dest); + emit_insn_after (new_move, bb_note (call_dom)); + if (dump_file) + { + fprintf (dump_file, "Split live-range of register "); + print_rtl_single (dump_file, dest); + } + ret = true; + } + + if (insn == last_interesting_insn) + break; + } + apply_change_group (); + return ret; } /* Perform the second half of the transformation started in @@ -5049,7 +5228,22 @@ ira (FILE *f) allocation because of -O0 usage or because the function is too big. */ if (ira_conflicts_p) - find_moveable_pseudos (); + { + df_analyze (); + calculate_dominance_info (CDI_DOMINATORS); + + find_moveable_pseudos (); + if (split_live_ranges_for_shrink_wrap ()) + df_analyze (); + + fix_reg_equiv_init (); + expand_reg_info (); + regstat_free_n_sets_and_refs (); + regstat_free_ri (); + regstat_init_n_sets_and_refs (); + regstat_compute_ri (); + free_dominance_info (CDI_DOMINATORS); + } max_regno_before_ira = max_reg_num (); ira_setup_eliminable_regset (true); |