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Diffstat (limited to 'gcc-4.8.1/gcc/tree-ssanames.c')
| -rw-r--r-- | gcc-4.8.1/gcc/tree-ssanames.c | 461 |
1 files changed, 0 insertions, 461 deletions
diff --git a/gcc-4.8.1/gcc/tree-ssanames.c b/gcc-4.8.1/gcc/tree-ssanames.c deleted file mode 100644 index 0a405ce2a..000000000 --- a/gcc-4.8.1/gcc/tree-ssanames.c +++ /dev/null @@ -1,461 +0,0 @@ -/* Generic routines for manipulating SSA_NAME expressions - Copyright (C) 2003-2013 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 3, or (at your option) -any later version. - -GCC is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -GNU General Public License for more details. - -You should have received a copy of the GNU General Public License -along with GCC; see the file COPYING3. If not see -<http://www.gnu.org/licenses/>. */ - -#include "config.h" -#include "system.h" -#include "coretypes.h" -#include "tm.h" -#include "tree.h" -#include "tree-flow.h" -#include "tree-pass.h" - -/* Rewriting a function into SSA form can create a huge number of SSA_NAMEs, - many of which may be thrown away shortly after their creation if jumps - were threaded through PHI nodes. - - While our garbage collection mechanisms will handle this situation, it - is extremely wasteful to create nodes and throw them away, especially - when the nodes can be reused. - - For PR 8361, we can significantly reduce the number of nodes allocated - and thus the total amount of memory allocated by managing SSA_NAMEs a - little. This additionally helps reduce the amount of work done by the - garbage collector. Similar results have been seen on a wider variety - of tests (such as the compiler itself). - - Right now we maintain our free list on a per-function basis. It may - or may not make sense to maintain the free list for the duration of - a compilation unit. - - External code should rely solely upon HIGHEST_SSA_VERSION and the - externally defined functions. External code should not know about - the details of the free list management. - - External code should also not assume the version number on nodes is - monotonically increasing. We reuse the version number when we - reuse an SSA_NAME expression. This helps keep arrays and bitmaps - more compact. */ - - -/* Version numbers with special meanings. We start allocating new version - numbers after the special ones. */ -#define UNUSED_NAME_VERSION 0 - -unsigned int ssa_name_nodes_reused; -unsigned int ssa_name_nodes_created; - -/* Initialize management of SSA_NAMEs to default SIZE. If SIZE is - zero use default. */ - -void -init_ssanames (struct function *fn, int size) -{ - if (size < 50) - size = 50; - - vec_alloc (SSANAMES (fn), size); - - /* Version 0 is special, so reserve the first slot in the table. Though - currently unused, we may use version 0 in alias analysis as part of - the heuristics used to group aliases when the alias sets are too - large. - - We use vec::quick_push here because we know that SSA_NAMES has at - least 50 elements reserved in it. */ - SSANAMES (fn)->quick_push (NULL_TREE); - FREE_SSANAMES (fn) = NULL; - - fn->gimple_df->ssa_renaming_needed = 0; - fn->gimple_df->rename_vops = 0; -} - -/* Finalize management of SSA_NAMEs. */ - -void -fini_ssanames (void) -{ - vec_free (SSANAMES (cfun)); - vec_free (FREE_SSANAMES (cfun)); -} - -/* Dump some simple statistics regarding the re-use of SSA_NAME nodes. */ - -void -ssanames_print_statistics (void) -{ - fprintf (stderr, "SSA_NAME nodes allocated: %u\n", ssa_name_nodes_created); - fprintf (stderr, "SSA_NAME nodes reused: %u\n", ssa_name_nodes_reused); -} - -/* Return an SSA_NAME node for variable VAR defined in statement STMT - in function FN. STMT may be an empty statement for artificial - references (e.g., default definitions created when a variable is - used without a preceding definition). */ - -tree -make_ssa_name_fn (struct function *fn, tree var, gimple stmt) -{ - tree t; - use_operand_p imm; - - gcc_assert (TREE_CODE (var) == VAR_DECL - || TREE_CODE (var) == PARM_DECL - || TREE_CODE (var) == RESULT_DECL - || (TYPE_P (var) && is_gimple_reg_type (var))); - - /* If our free list has an element, then use it. */ - if (!vec_safe_is_empty (FREE_SSANAMES (fn))) - { - t = FREE_SSANAMES (fn)->pop (); - if (GATHER_STATISTICS) - ssa_name_nodes_reused++; - - /* The node was cleared out when we put it on the free list, so - there is no need to do so again here. */ - gcc_assert (ssa_name (SSA_NAME_VERSION (t)) == NULL); - (*SSANAMES (fn))[SSA_NAME_VERSION (t)] = t; - } - else - { - t = make_node (SSA_NAME); - SSA_NAME_VERSION (t) = SSANAMES (fn)->length (); - vec_safe_push (SSANAMES (fn), t); - if (GATHER_STATISTICS) - ssa_name_nodes_created++; - } - - if (TYPE_P (var)) - { - TREE_TYPE (t) = var; - SET_SSA_NAME_VAR_OR_IDENTIFIER (t, NULL_TREE); - } - else - { - TREE_TYPE (t) = TREE_TYPE (var); - SET_SSA_NAME_VAR_OR_IDENTIFIER (t, var); - } - SSA_NAME_DEF_STMT (t) = stmt; - SSA_NAME_PTR_INFO (t) = NULL; - SSA_NAME_IN_FREE_LIST (t) = 0; - SSA_NAME_IS_DEFAULT_DEF (t) = 0; - imm = &(SSA_NAME_IMM_USE_NODE (t)); - imm->use = NULL; - imm->prev = imm; - imm->next = imm; - imm->loc.ssa_name = t; - - return t; -} - - -/* We no longer need the SSA_NAME expression VAR, release it so that - it may be reused. - - Note it is assumed that no calls to make_ssa_name will be made - until all uses of the ssa name are released and that the only - use of the SSA_NAME expression is to check its SSA_NAME_VAR. All - other fields must be assumed clobbered. */ - -void -release_ssa_name (tree var) -{ - if (!var) - return; - - /* Never release the default definition for a symbol. It's a - special SSA name that should always exist once it's created. */ - if (SSA_NAME_IS_DEFAULT_DEF (var)) - return; - - /* If VAR has been registered for SSA updating, don't remove it. - After update_ssa has run, the name will be released. */ - if (name_registered_for_update_p (var)) - { - release_ssa_name_after_update_ssa (var); - return; - } - - /* release_ssa_name can be called multiple times on a single SSA_NAME. - However, it should only end up on our free list one time. We - keep a status bit in the SSA_NAME node itself to indicate it has - been put on the free list. - - Note that once on the freelist you can not reference the SSA_NAME's - defining statement. */ - if (! SSA_NAME_IN_FREE_LIST (var)) - { - tree saved_ssa_name_var = SSA_NAME_VAR (var); - int saved_ssa_name_version = SSA_NAME_VERSION (var); - use_operand_p imm = &(SSA_NAME_IMM_USE_NODE (var)); - - if (MAY_HAVE_DEBUG_STMTS) - insert_debug_temp_for_var_def (NULL, var); - -#ifdef ENABLE_CHECKING - verify_imm_links (stderr, var); -#endif - while (imm->next != imm) - delink_imm_use (imm->next); - - (*SSANAMES (cfun))[SSA_NAME_VERSION (var)] = NULL_TREE; - memset (var, 0, tree_size (var)); - - imm->prev = imm; - imm->next = imm; - imm->loc.ssa_name = var; - - /* First put back the right tree node so that the tree checking - macros do not complain. */ - TREE_SET_CODE (var, SSA_NAME); - - /* Restore the version number. */ - SSA_NAME_VERSION (var) = saved_ssa_name_version; - - /* Hopefully this can go away once we have the new incremental - SSA updating code installed. */ - SET_SSA_NAME_VAR_OR_IDENTIFIER (var, saved_ssa_name_var); - - /* Note this SSA_NAME is now in the first list. */ - SSA_NAME_IN_FREE_LIST (var) = 1; - - /* And finally put it on the free list. */ - vec_safe_push (FREE_SSANAMES (cfun), var); - } -} - -/* If the alignment of the pointer described by PI is known, return true and - store the alignment and the deviation from it into *ALIGNP and *MISALIGNP - respectively. Otherwise return false. */ - -bool -get_ptr_info_alignment (struct ptr_info_def *pi, unsigned int *alignp, - unsigned int *misalignp) -{ - if (pi->align) - { - *alignp = pi->align; - *misalignp = pi->misalign; - return true; - } - else - return false; -} - -/* State that the pointer described by PI has unknown alignment. */ - -void -mark_ptr_info_alignment_unknown (struct ptr_info_def *pi) -{ - pi->align = 0; - pi->misalign = 0; -} - -/* Store the the power-of-two byte alignment and the deviation from that - alignment of pointer described by PI to ALIOGN and MISALIGN - respectively. */ - -void -set_ptr_info_alignment (struct ptr_info_def *pi, unsigned int align, - unsigned int misalign) -{ - gcc_checking_assert (align != 0); - gcc_assert ((align & (align - 1)) == 0); - gcc_assert ((misalign & ~(align - 1)) == 0); - - pi->align = align; - pi->misalign = misalign; -} - -/* If pointer described by PI has known alignment, increase its known - misalignment by INCREMENT modulo its current alignment. */ - -void -adjust_ptr_info_misalignment (struct ptr_info_def *pi, - unsigned int increment) -{ - if (pi->align != 0) - { - pi->misalign += increment; - pi->misalign &= (pi->align - 1); - } -} - -/* Return the alias information associated with pointer T. It creates a - new instance if none existed. */ - -struct ptr_info_def * -get_ptr_info (tree t) -{ - struct ptr_info_def *pi; - - gcc_assert (POINTER_TYPE_P (TREE_TYPE (t))); - - pi = SSA_NAME_PTR_INFO (t); - if (pi == NULL) - { - pi = ggc_alloc_cleared_ptr_info_def (); - pt_solution_reset (&pi->pt); - mark_ptr_info_alignment_unknown (pi); - SSA_NAME_PTR_INFO (t) = pi; - } - - return pi; -} - - -/* Creates a new SSA name using the template NAME tobe defined by - statement STMT in function FN. */ - -tree -copy_ssa_name_fn (struct function *fn, tree name, gimple stmt) -{ - tree new_name; - - if (SSA_NAME_VAR (name)) - new_name = make_ssa_name_fn (fn, SSA_NAME_VAR (name), stmt); - else - { - new_name = make_ssa_name_fn (fn, TREE_TYPE (name), stmt); - SET_SSA_NAME_VAR_OR_IDENTIFIER (new_name, SSA_NAME_IDENTIFIER (name)); - } - - return new_name; -} - - -/* Creates a duplicate of the ptr_info_def at PTR_INFO for use by - the SSA name NAME. */ - -void -duplicate_ssa_name_ptr_info (tree name, struct ptr_info_def *ptr_info) -{ - struct ptr_info_def *new_ptr_info; - - gcc_assert (POINTER_TYPE_P (TREE_TYPE (name))); - gcc_assert (!SSA_NAME_PTR_INFO (name)); - - if (!ptr_info) - return; - - new_ptr_info = ggc_alloc_ptr_info_def (); - *new_ptr_info = *ptr_info; - - SSA_NAME_PTR_INFO (name) = new_ptr_info; -} - - -/* Creates a duplicate of a ssa name NAME tobe defined by statement STMT - in function FN. */ - -tree -duplicate_ssa_name_fn (struct function *fn, tree name, gimple stmt) -{ - tree new_name = copy_ssa_name_fn (fn, name, stmt); - struct ptr_info_def *old_ptr_info = SSA_NAME_PTR_INFO (name); - - if (old_ptr_info) - duplicate_ssa_name_ptr_info (new_name, old_ptr_info); - - return new_name; -} - - -/* Release all the SSA_NAMEs created by STMT. */ - -void -release_defs (gimple stmt) -{ - tree def; - ssa_op_iter iter; - - /* Make sure that we are in SSA. Otherwise, operand cache may point - to garbage. */ - gcc_assert (gimple_in_ssa_p (cfun)); - - FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) - if (TREE_CODE (def) == SSA_NAME) - release_ssa_name (def); -} - - -/* Replace the symbol associated with SSA_NAME with SYM. */ - -void -replace_ssa_name_symbol (tree ssa_name, tree sym) -{ - SET_SSA_NAME_VAR_OR_IDENTIFIER (ssa_name, sym); - TREE_TYPE (ssa_name) = TREE_TYPE (sym); -} - -/* Return SSA names that are unused to GGC memory and compact the SSA - version namespace. This is used to keep footprint of compiler during - interprocedural optimization. */ -static unsigned int -release_dead_ssa_names (void) -{ - unsigned i, j; - int n = vec_safe_length (FREE_SSANAMES (cfun)); - - /* Now release the freelist. */ - vec_free (FREE_SSANAMES (cfun)); - - /* And compact the SSA number space. We make sure to not change the - relative order of SSA versions. */ - for (i = 1, j = 1; i < cfun->gimple_df->ssa_names->length (); ++i) - { - tree name = ssa_name (i); - if (name) - { - if (i != j) - { - SSA_NAME_VERSION (name) = j; - (*cfun->gimple_df->ssa_names)[j] = name; - } - j++; - } - } - cfun->gimple_df->ssa_names->truncate (j); - - statistics_counter_event (cfun, "SSA names released", n); - statistics_counter_event (cfun, "SSA name holes removed", i - j); - if (dump_file) - fprintf (dump_file, "Released %i names, %.2f%%, removed %i holes\n", - n, n * 100.0 / num_ssa_names, i - j); - return 0; -} - -struct gimple_opt_pass pass_release_ssa_names = -{ - { - GIMPLE_PASS, - "release_ssa", /* name */ - OPTGROUP_NONE, /* optinfo_flags */ - NULL, /* gate */ - release_dead_ssa_names, /* execute */ - NULL, /* sub */ - NULL, /* next */ - 0, /* static_pass_number */ - TV_TREE_SSA_OTHER, /* tv_id */ - PROP_ssa, /* properties_required */ - 0, /* properties_provided */ - 0, /* properties_destroyed */ - TODO_remove_unused_locals, /* todo_flags_start */ - 0 /* todo_flags_finish */ - } -}; |