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Diffstat (limited to 'gcc-4.2.1-5666.3/gcc/web.c')
| -rw-r--r-- | gcc-4.2.1-5666.3/gcc/web.c | 324 |
1 files changed, 0 insertions, 324 deletions
diff --git a/gcc-4.2.1-5666.3/gcc/web.c b/gcc-4.2.1-5666.3/gcc/web.c deleted file mode 100644 index 7f5ae67d9..000000000 --- a/gcc-4.2.1-5666.3/gcc/web.c +++ /dev/null @@ -1,324 +0,0 @@ -/* Web construction code for GNU compiler. - Contributed by Jan Hubicka. - Copyright (C) 2001, 2002, 2004, 2006 - Free Software Foundation, Inc. - -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 2, 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 COPYING. If not, write to the Free -Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301, USA. */ - -/* Simple optimization pass that splits independent uses of each pseudo, - increasing effectiveness of other optimizations. The optimization can - serve as an example of use for the dataflow module. - - We don't split registers with REG_USERVAR set unless -fmessy-debugging - is specified, because debugging information about such split variables - is almost unusable. - - TODO - - Add code to keep debugging up-to-date after splitting user variable - pseudos. This can be done by keeping track of all the pseudos used - for the variable and using life analysis information before reload - to determine which one is live and, in case more than one are live, - choose the one with the latest definition. - - Other optimization passes can benefit from the infrastructure too. - - - We may use profile information and ignore infrequent use for the - purpose of web unifying, inserting the compensation code later to - implement full induction variable expansion for loops (currently - we expand only if the induction variable is dead afterward, which - is often the case). */ - -#include "config.h" -#include "system.h" -#include "coretypes.h" -#include "tm.h" -#include "toplev.h" - -#include "rtl.h" -#include "hard-reg-set.h" -#include "flags.h" -#include "obstack.h" -#include "basic-block.h" -#include "output.h" -#include "df.h" -#include "function.h" -#include "timevar.h" -#include "tree-pass.h" - - -static rtx entry_register (struct web_entry *, struct df_ref *, char *); -static void replace_ref (struct df_ref *, rtx); - -/* Find the root of unionfind tree (the representative of set). */ - -struct web_entry * -unionfind_root (struct web_entry *element) -{ - struct web_entry *element1 = element, *element2; - - while (element->pred) - element = element->pred; - while (element1->pred) - { - element2 = element1->pred; - element1->pred = element; - element1 = element2; - } - return element; -} - -/* Union sets. - Return true if FIRST and SECOND points to the same web entry structure and - nothing is done. Otherwise, return false. */ - -bool -unionfind_union (struct web_entry *first, struct web_entry *second) -{ - first = unionfind_root (first); - second = unionfind_root (second); - if (first == second) - return true; - second->pred = first; - return false; -} - -/* For each use, all possible defs reaching it must come in the same - register, union them. - FUN is the function that does the union. */ - -void -union_defs (struct df *df, struct df_ref *use, struct web_entry *def_entry, - struct web_entry *use_entry, - bool (*fun) (struct web_entry *, struct web_entry *)) -{ - rtx insn = DF_REF_INSN (use); - struct df_link *link = DF_REF_CHAIN (use); - struct df_ref *use_link; - struct df_ref *def_link; - rtx set; - - if (insn) - { - use_link = DF_INSN_USES (df, insn); - def_link = DF_INSN_DEFS (df, insn); - set = single_set (insn); - } - else - { - use_link = NULL; - def_link = NULL; - set = NULL; - } - - /* Some instructions may use match_dup for their operands. In case the - operands are dead, we will assign them different pseudos, creating - invalid instructions, so union all uses of the same operand for each - insn. */ - - while (use_link) - { - if (use != use_link - && DF_REF_REAL_REG (use) == DF_REF_REAL_REG (use_link)) - (*fun) (use_entry + DF_REF_ID (use), - use_entry + DF_REF_ID (use_link)); - use_link = use_link->next_ref; - } - - /* Recognize trivial noop moves and attempt to keep them as noop. - While most of noop moves should be removed, we still keep some - of them at libcall boundaries and such. */ - - if (set - && SET_SRC (set) == DF_REF_REG (use) - && SET_SRC (set) == SET_DEST (set)) - { - while (def_link) - { - if (DF_REF_REAL_REG (use) == DF_REF_REAL_REG (def_link)) - (*fun) (use_entry + DF_REF_ID (use), - def_entry + DF_REF_ID (def_link)); - def_link = def_link->next_ref; - } - } - while (link) - { - (*fun) (use_entry + DF_REF_ID (use), - def_entry + DF_REF_ID (link->ref)); - link = link->next; - } - - /* A READ_WRITE use requires the corresponding def to be in the same - register. Find it and union. */ - if (use->flags & DF_REF_READ_WRITE) - { - struct df_ref *link; - - if (DF_REF_INSN (use)) - link = DF_INSN_DEFS (df, DF_REF_INSN (use)); - else - link = NULL; - - while (link) - { - if (DF_REF_REAL_REG (link) == DF_REF_REAL_REG (use)) - (*fun) (use_entry + DF_REF_ID (use), - def_entry + DF_REF_ID (link)); - link = link->next_ref; - } - } -} - -/* Find the corresponding register for the given entry. */ - -static rtx -entry_register (struct web_entry *entry, struct df_ref *ref, char *used) -{ - struct web_entry *root; - rtx reg, newreg; - - /* Find the corresponding web and see if it has been visited. */ - root = unionfind_root (entry); - if (root->reg) - return root->reg; - - /* We are seeing this web for the first time, do the assignment. */ - reg = DF_REF_REAL_REG (ref); - - /* In case the original register is already assigned, generate new one. */ - if (!used[REGNO (reg)]) - newreg = reg, used[REGNO (reg)] = 1; - else if (REG_USERVAR_P (reg) && 0/*&& !flag_messy_debugging*/) - { - newreg = reg; - if (dump_file) - fprintf (dump_file, - "New web forced to keep reg=%i (user variable)\n", - REGNO (reg)); - } - else - { - newreg = gen_reg_rtx (GET_MODE (reg)); - REG_USERVAR_P (newreg) = REG_USERVAR_P (reg); - REG_POINTER (newreg) = REG_POINTER (reg); - REG_ATTRS (newreg) = REG_ATTRS (reg); - if (dump_file) - fprintf (dump_file, "Web oldreg=%i newreg=%i\n", REGNO (reg), - REGNO (newreg)); - } - - root->reg = newreg; - return newreg; -} - -/* Replace the reference by REG. */ - -static void -replace_ref (struct df_ref *ref, rtx reg) -{ - rtx oldreg = DF_REF_REAL_REG (ref); - rtx *loc = DF_REF_REAL_LOC (ref); - - if (oldreg == reg) - return; - if (dump_file) - fprintf (dump_file, "Updating insn %i (%i->%i)\n", - INSN_UID (DF_REF_INSN (ref)), REGNO (oldreg), REGNO (reg)); - *loc = reg; -} - -/* Main entry point. */ - -static void -web_main (void) -{ - struct df *df; - struct web_entry *def_entry; - struct web_entry *use_entry; - unsigned int i; - int max = max_reg_num (); - char *used; - - df = df_init (DF_EQUIV_NOTES); - df_chain_add_problem (df, DF_UD_CHAIN); - df_analyze (df); - df_reorganize_refs (&df->def_info); - df_reorganize_refs (&df->use_info); - - def_entry = XCNEWVEC (struct web_entry, DF_DEFS_SIZE (df)); - use_entry = XCNEWVEC (struct web_entry, DF_USES_SIZE (df)); - used = XCNEWVEC (char, max); - - if (dump_file) - df_dump (df, dump_file); - - /* Produce the web. */ - for (i = 0; i < DF_USES_SIZE (df); i++) - union_defs (df, DF_USES_GET (df, i), def_entry, use_entry, unionfind_union); - - /* Update the instruction stream, allocating new registers for split pseudos - in progress. */ - for (i = 0; i < DF_USES_SIZE (df); i++) - replace_ref (DF_USES_GET (df, i), - entry_register (use_entry + i, DF_USES_GET (df, i), used)); - for (i = 0; i < DF_DEFS_SIZE (df); i++) - replace_ref (DF_DEFS_GET (df, i), - entry_register (def_entry + i, DF_DEFS_GET (df, i), used)); - - /* Dataflow information is corrupt here, but it can be easily updated - by creating new entries for new registers and updates or calling - df_insns_modify. */ - free (def_entry); - free (use_entry); - free (used); - df_finish (df); - df = NULL; -} - -static bool -gate_handle_web (void) -{ - return (optimize > 0 && flag_web); -} - -static unsigned int -rest_of_handle_web (void) -{ - web_main (); - delete_trivially_dead_insns (get_insns (), max_reg_num ()); - cleanup_cfg (CLEANUP_EXPENSIVE); - reg_scan (get_insns (), max_reg_num ()); - return 0; -} - -struct tree_opt_pass pass_web = -{ - "web", /* name */ - gate_handle_web, /* gate */ - rest_of_handle_web, /* execute */ - NULL, /* sub */ - NULL, /* next */ - 0, /* static_pass_number */ - TV_WEB, /* tv_id */ - 0, /* properties_required */ - 0, /* properties_provided */ - 0, /* properties_destroyed */ - 0, /* todo_flags_start */ - TODO_dump_func, /* todo_flags_finish */ - 'Z' /* letter */ -}; - |