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Re: rfa: merge handling of locals and globals in remove_unused_locals
On Wed, Aug 1, 2012 at 5:28 PM, Michael Matz <matz@suse.de> wrote:
> Hi,
>
> On Wed, 1 Aug 2012, Richard Guenther wrote:
>
>> Ok. Would be nice to now unify global and local var handling with a
>> single bitmap.
>
> Yeah, wanted to do that as follow-up. Namely like so. Regstrapping on
> x86_64-linux in progress on top of your remove-referenced-vars patches.
> Okay for trunk?
Ok.
Thanks,
Richard.
>
> Ciao,
> Michael.
> --
> * tree-ssa-live.c (set_is_used): Return a bool.
> (mark_all_vars_used): Don't take data argument.
> (mark_all_vars_used_1): Adjust calls to above, merge handling
> of local and global vars.
> (remove_unused_scope_block_p): Don't take global_unused_vars,
> merge handling of local and global vars.
> (remove_unused_locals): Don't allocate/fill/pass global_unused_vars,
> use is_used_p for local and global vars.
>
> Index: gcc/tree-ssa-live.c
> ===================================================================
> *** gcc.orig/tree-ssa-live.c 2012-08-01 17:21:39.000000000 +0200
> --- gcc/tree-ssa-live.c 2012-08-01 17:22:01.000000000 +0200
> *************** partition_view_bitmap (var_map map, bitm
> *** 331,342 ****
>
> static bitmap usedvars;
>
> ! /* Mark VAR as used, so that it'll be preserved during rtl expansion. */
>
> ! static inline void
> set_is_used (tree var)
> {
> ! bitmap_set_bit (usedvars, DECL_UID (var));
> }
>
> /* Return true if VAR is marked as used. */
> --- 331,343 ----
>
> static bitmap usedvars;
>
> ! /* Mark VAR as used, so that it'll be preserved during rtl expansion.
> ! Returns true if VAR wasn't marked before. */
>
> ! static inline bool
> set_is_used (tree var)
> {
> ! return bitmap_set_bit (usedvars, DECL_UID (var));
> }
>
> /* Return true if VAR is marked as used. */
> *************** is_used_p (tree var)
> *** 347,360 ****
> return bitmap_bit_p (usedvars, DECL_UID (var));
> }
>
> ! static inline void mark_all_vars_used (tree *, void *data);
>
> /* Helper function for mark_all_vars_used, called via walk_tree. */
>
> static tree
> ! mark_all_vars_used_1 (tree *tp, int *walk_subtrees, void *data)
> {
> - bitmap global_unused_vars = (bitmap)data;
> tree t = *tp;
> enum tree_code_class c = TREE_CODE_CLASS (TREE_CODE (t));
> tree b;
> --- 348,360 ----
> return bitmap_bit_p (usedvars, DECL_UID (var));
> }
>
> ! static inline void mark_all_vars_used (tree *);
>
> /* Helper function for mark_all_vars_used, called via walk_tree. */
>
> static tree
> ! mark_all_vars_used_1 (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
> {
> tree t = *tp;
> enum tree_code_class c = TREE_CODE_CLASS (TREE_CODE (t));
> tree b;
> *************** mark_all_vars_used_1 (tree *tp, int *wal
> *** 370,378 ****
> fields do not contain vars. */
> if (TREE_CODE (t) == TARGET_MEM_REF)
> {
> ! mark_all_vars_used (&TMR_BASE (t), data);
> ! mark_all_vars_used (&TMR_INDEX (t), data);
> ! mark_all_vars_used (&TMR_INDEX2 (t), data);
> *walk_subtrees = 0;
> return NULL;
> }
> --- 370,378 ----
> fields do not contain vars. */
> if (TREE_CODE (t) == TARGET_MEM_REF)
> {
> ! mark_all_vars_used (&TMR_BASE (t));
> ! mark_all_vars_used (&TMR_INDEX (t));
> ! mark_all_vars_used (&TMR_INDEX2 (t));
> *walk_subtrees = 0;
> return NULL;
> }
> *************** mark_all_vars_used_1 (tree *tp, int *wal
> *** 381,396 ****
> eliminated as unused. */
> if (TREE_CODE (t) == VAR_DECL)
> {
> ! /* Global vars do not have a var-annotation so their use is tracked
> ! with the global_unused_vars bitmap. Also walk their initializer
> ! when they are first recognized as used. */
> ! if (is_global_var (t))
> ! {
> ! if (bitmap_clear_bit (global_unused_vars, DECL_UID (t)))
> ! mark_all_vars_used (&DECL_INITIAL (t), data);
> ! }
> ! else
> ! set_is_used (t);
> }
> /* remove_unused_scope_block_p requires information about labels
> which are not DECL_IGNORED_P to tell if they might be used in the IL. */
> --- 381,390 ----
> eliminated as unused. */
> if (TREE_CODE (t) == VAR_DECL)
> {
> ! /* When a global var becomes used for the first time also walk its
> ! initializer (non global ones don't have any). */
> ! if (set_is_used (t) && is_global_var (t))
> ! mark_all_vars_used (&DECL_INITIAL (t));
> }
> /* remove_unused_scope_block_p requires information about labels
> which are not DECL_IGNORED_P to tell if they might be used in the IL. */
> *************** mark_scope_block_unused (tree scope)
> *** 435,441 ****
> done by the inliner. */
>
> static bool
> ! remove_unused_scope_block_p (tree scope, bitmap global_unused_vars)
> {
> tree *t, *next;
> bool unused = !TREE_USED (scope);
> --- 429,435 ----
> done by the inliner. */
>
> static bool
> ! remove_unused_scope_block_p (tree scope)
> {
> tree *t, *next;
> bool unused = !TREE_USED (scope);
> *************** remove_unused_scope_block_p (tree scope,
> *** 475,483 ****
> info about optimized-out variables in the scope blocks.
> Exception are the scope blocks not containing any instructions
> at all so user can't get into the scopes at first place. */
> ! else if ((is_global_var (*t)
> ! && !bitmap_bit_p (global_unused_vars, DECL_UID (*t)))
> ! || is_used_p (*t))
> unused = false;
> else if (TREE_CODE (*t) == LABEL_DECL && TREE_USED (*t))
> /* For labels that are still used in the IL, the decision to
> --- 469,475 ----
> info about optimized-out variables in the scope blocks.
> Exception are the scope blocks not containing any instructions
> at all so user can't get into the scopes at first place. */
> ! else if (is_used_p (*t))
> unused = false;
> else if (TREE_CODE (*t) == LABEL_DECL && TREE_USED (*t))
> /* For labels that are still used in the IL, the decision to
> *************** remove_unused_scope_block_p (tree scope,
> *** 522,528 ****
> }
>
> for (t = &BLOCK_SUBBLOCKS (scope); *t ;)
> ! if (remove_unused_scope_block_p (*t, global_unused_vars))
> {
> if (BLOCK_SUBBLOCKS (*t))
> {
> --- 514,520 ----
> }
>
> for (t = &BLOCK_SUBBLOCKS (scope); *t ;)
> ! if (remove_unused_scope_block_p (*t))
> {
> if (BLOCK_SUBBLOCKS (*t))
> {
> *************** remove_unused_scope_block_p (tree scope,
> *** 603,611 ****
> eliminated during the tree->rtl conversion process. */
>
> static inline void
> ! mark_all_vars_used (tree *expr_p, void *data)
> {
> ! walk_tree (expr_p, mark_all_vars_used_1, data, NULL);
> }
>
>
> --- 595,603 ----
> eliminated during the tree->rtl conversion process. */
>
> static inline void
> ! mark_all_vars_used (tree *expr_p)
> {
> ! walk_tree (expr_p, mark_all_vars_used_1, NULL, NULL);
> }
>
>
> *************** remove_unused_locals (void)
> *** 693,700 ****
> {
> basic_block bb;
> tree var;
> ! bitmap global_unused_vars = NULL;
> ! unsigned srcidx, dstidx, num, ix;
> bool have_local_clobbers = false;
>
> /* Removing declarations from lexical blocks when not optimizing is
> --- 685,691 ----
> {
> basic_block bb;
> tree var;
> ! unsigned srcidx, dstidx, num;
> bool have_local_clobbers = false;
>
> /* Removing declarations from lexical blocks when not optimizing is
> *************** remove_unused_locals (void)
> *** 709,721 ****
>
> usedvars = BITMAP_ALLOC (NULL);
>
> - /* Assume all globals in local decls are unused. */
> - global_unused_vars = BITMAP_ALLOC (NULL);
> - FOR_EACH_LOCAL_DECL (cfun, ix, var)
> - if (TREE_CODE (var) == VAR_DECL
> - && is_global_var (var))
> - bitmap_set_bit (global_unused_vars, DECL_UID (var));
> -
> /* Walk the CFG marking all referenced symbols. */
> FOR_EACH_BB (bb)
> {
> --- 700,705 ----
> *************** remove_unused_locals (void)
> *** 743,750 ****
> TREE_USED (b) = true;
>
> for (i = 0; i < gimple_num_ops (stmt); i++)
> ! mark_all_vars_used (gimple_op_ptr (gsi_stmt (gsi), i),
> ! global_unused_vars);
> }
>
> for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
> --- 727,733 ----
> TREE_USED (b) = true;
>
> for (i = 0; i < gimple_num_ops (stmt); i++)
> ! mark_all_vars_used (gimple_op_ptr (gsi_stmt (gsi), i));
> }
>
> for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
> *************** remove_unused_locals (void)
> *** 758,769 ****
> continue;
>
> def = gimple_phi_result (phi);
> ! mark_all_vars_used (&def, global_unused_vars);
>
> FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_ALL_USES)
> {
> tree arg = USE_FROM_PTR (arg_p);
> ! mark_all_vars_used (&arg, global_unused_vars);
> }
> }
>
> --- 741,752 ----
> continue;
>
> def = gimple_phi_result (phi);
> ! mark_all_vars_used (&def);
>
> FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_ALL_USES)
> {
> tree arg = USE_FROM_PTR (arg_p);
> ! mark_all_vars_used (&arg);
> }
> }
>
> *************** remove_unused_locals (void)
> *** 793,802 ****
> lhs = get_base_address (lhs);
> if (TREE_CODE (lhs) == SSA_NAME)
> lhs = SSA_NAME_VAR (lhs);
> ! if (TREE_CODE (lhs) == VAR_DECL
> ! && ((is_global_var (lhs)
> ! && bitmap_bit_p (global_unused_vars, DECL_UID (lhs)))
> ! || (!is_global_var (lhs) && !is_used_p (lhs))))
> {
> unlink_stmt_vdef (stmt);
> gsi_remove (&gsi, true);
> --- 776,782 ----
> lhs = get_base_address (lhs);
> if (TREE_CODE (lhs) == SSA_NAME)
> lhs = SSA_NAME_VAR (lhs);
> ! if (TREE_CODE (lhs) == VAR_DECL && !is_used_p (lhs))
> {
> unlink_stmt_vdef (stmt);
> gsi_remove (&gsi, true);
> *************** remove_unused_locals (void)
> *** 812,831 ****
>
> cfun->has_local_explicit_reg_vars = false;
>
> ! /* Remove unmarked local and global vars from local_decls
> ! and referenced vars. */
> num = VEC_length (tree, cfun->local_decls);
> for (srcidx = 0, dstidx = 0; srcidx < num; srcidx++)
> {
> var = VEC_index (tree, cfun->local_decls, srcidx);
> if (TREE_CODE (var) == VAR_DECL)
> {
> ! if (is_global_var (var))
> ! {
> ! if (bitmap_bit_p (global_unused_vars, DECL_UID (var)))
> ! continue;
> ! }
> ! else if (!is_used_p (var))
> {
> if (cfun->nonlocal_goto_save_area
> && TREE_OPERAND (cfun->nonlocal_goto_save_area, 0) == var)
> --- 792,805 ----
>
> cfun->has_local_explicit_reg_vars = false;
>
> ! /* Remove unmarked local and global vars from local_decls. */
> num = VEC_length (tree, cfun->local_decls);
> for (srcidx = 0, dstidx = 0; srcidx < num; srcidx++)
> {
> var = VEC_index (tree, cfun->local_decls, srcidx);
> if (TREE_CODE (var) == VAR_DECL)
> {
> ! if (!is_used_p (var))
> {
> if (cfun->nonlocal_goto_save_area
> && TREE_OPERAND (cfun->nonlocal_goto_save_area, 0) == var)
> *************** remove_unused_locals (void)
> *** 845,854 ****
> if (dstidx != num)
> VEC_truncate (tree, cfun->local_decls, dstidx);
>
> ! remove_unused_scope_block_p (DECL_INITIAL (current_function_decl),
> ! global_unused_vars);
>
> - BITMAP_FREE (global_unused_vars);
> BITMAP_FREE (usedvars);
>
> if (dump_file && (dump_flags & TDF_DETAILS))
> --- 819,826 ----
> if (dstidx != num)
> VEC_truncate (tree, cfun->local_decls, dstidx);
>
> ! remove_unused_scope_block_p (DECL_INITIAL (current_function_decl));
>
> BITMAP_FREE (usedvars);
>
> if (dump_file && (dump_flags & TDF_DETAILS))