/* Liveness for SSA trees.
- Copyright (C) 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009 Free Software Foundation,
+ Inc.
Contributed by Andrew MacLeod <amacleod@redhat.com>
This file is part of GCC.
At the end of out-of-ssa, each partition becomes a "real" variable and is
rewritten as a compiler variable.
- The var_map datat structure is used to manage these partitions. It allows
+ The var_map data structure is used to manage these partitions. It allows
partitions to be combined, and determines which partition belongs to what
ssa_name or variable, and vice versa. */
}
-static inline void mark_all_vars_used (tree *);
+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 ATTRIBUTE_UNUSED)
+mark_all_vars_used_1 (tree *tp, int *walk_subtrees, void *data)
{
tree t = *tp;
enum tree_code_class c = TREE_CODE_CLASS (TREE_CODE (t));
if (TREE_CODE (t) == SSA_NAME)
t = SSA_NAME_VAR (t);
- if ((IS_EXPR_CODE_CLASS (c)
- || IS_GIMPLE_STMT_CODE_CLASS (c))
+
+ if (IS_EXPR_CODE_CLASS (c)
&& (b = TREE_BLOCK (t)) != NULL)
TREE_USED (b) = true;
fields that do not contain vars. */
if (TREE_CODE (t) == TARGET_MEM_REF)
{
- mark_all_vars_used (&TMR_SYMBOL (t));
- mark_all_vars_used (&TMR_BASE (t));
- mark_all_vars_used (&TMR_INDEX (t));
+ mark_all_vars_used (&TMR_SYMBOL (t), data);
+ mark_all_vars_used (&TMR_BASE (t), data);
+ mark_all_vars_used (&TMR_INDEX (t), data);
*walk_subtrees = 0;
return NULL;
}
/* Only need to mark VAR_DECLS; parameters and return results are not
eliminated as unused. */
if (TREE_CODE (t) == VAR_DECL)
- set_is_used (t);
+ {
+ if (data != NULL && bitmap_bit_p ((bitmap) data, DECL_UID (t)))
+ {
+ bitmap_clear_bit ((bitmap) data, DECL_UID (t));
+ mark_all_vars_used (&DECL_INITIAL (t), data);
+ }
+ set_is_used (t);
+ }
if (IS_TYPE_OR_DECL_P (t))
*walk_subtrees = 0;
or there is precisely one subblocks and the block
has same abstract origin as outer block and declares
no variables, so it is pure wrapper.
- When we are not outputting full debug info, we also elliminate dead variables
+ When we are not outputting full debug info, we also eliminate dead variables
out of scope blocks to let them to be recycled by GGC and to save copying work
done by the inliner. */
{
next = &TREE_CHAIN (*t);
- /* Debug info of nested function reffers to the block of the
+ /* Debug info of nested function refers to the block of the
function. */
if (TREE_CODE (*t) == FUNCTION_DECL)
unused = false;
+ /* Remove everything we don't generate debug info for. */
+ else if (DECL_IGNORED_P (*t))
+ {
+ *t = TREE_CHAIN (*t);
+ next = t;
+ }
+
/* When we are outputting debug info, we usually want to output
info about optimized-out variables in the scope blocks.
Exception are the scope blocks not containing any instructions
/* When we are not doing full debug info, we however can keep around
only the used variables for cfgexpand's memory packing saving quite
a lot of memory. */
- else if (debug_info_level != DINFO_LEVEL_NORMAL
- && debug_info_level != DINFO_LEVEL_VERBOSE)
+ else if (debug_info_level == DINFO_LEVEL_NORMAL
+ || debug_info_level == DINFO_LEVEL_VERBOSE
+ /* Removing declarations before inlining is going to affect
+ DECL_UID that in turn is going to affect hashtables and
+ code generation. */
+ || !cfun->after_inlining)
+ unused = false;
+
+ else
{
*t = TREE_CHAIN (*t);
next = t;
nsubblocks ++;
}
else
- *t = BLOCK_CHAIN (*t);
+ {
+ gcc_assert (!BLOCK_VARS (*t));
+ *t = BLOCK_CHAIN (*t);
+ }
}
else
{
eliminated during the tree->rtl conversion process. */
static inline void
-mark_all_vars_used (tree *expr_p)
+mark_all_vars_used (tree *expr_p, void *data)
{
- walk_tree (expr_p, mark_all_vars_used_1, NULL, NULL);
+ walk_tree (expr_p, mark_all_vars_used_1, data, NULL);
}
tree t, *cell;
referenced_var_iterator rvi;
var_ann_t ann;
+ bitmap global_unused_vars = NULL;
+
+ if (optimize)
+ mark_scope_block_unused (DECL_INITIAL (current_function_decl));
- mark_scope_block_unused (DECL_INITIAL (current_function_decl));
/* Assume all locals are unused. */
FOR_EACH_REFERENCED_VAR (t, rvi)
var_ann (t)->used = false;
/* Walk the CFG marking all referenced symbols. */
FOR_EACH_BB (bb)
{
- block_stmt_iterator bsi;
- tree phi, def;
+ gimple_stmt_iterator gsi;
+ size_t i;
+ edge_iterator ei;
+ edge e;
/* Walk the statements. */
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- mark_all_vars_used (bsi_stmt_ptr (bsi));
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ tree b = gimple_block (stmt);
+
+ if (b)
+ TREE_USED (b) = true;
+
+ for (i = 0; i < gimple_num_ops (stmt); i++)
+ mark_all_vars_used (gimple_op_ptr (gsi_stmt (gsi), i), NULL);
+ }
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
+ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
use_operand_p arg_p;
ssa_op_iter i;
+ tree def;
+ gimple phi = gsi_stmt (gsi);
/* No point processing globals. */
- if (is_global_var (SSA_NAME_VAR (PHI_RESULT (phi))))
+ if (is_global_var (SSA_NAME_VAR (gimple_phi_result (phi))))
continue;
- def = PHI_RESULT (phi);
- mark_all_vars_used (&def);
+ def = gimple_phi_result (phi);
+ mark_all_vars_used (&def, NULL);
FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_ALL_USES)
{
tree arg = USE_FROM_PTR (arg_p);
- mark_all_vars_used (&arg);
+ mark_all_vars_used (&arg, NULL);
}
}
+
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (e->goto_locus)
+ TREE_USED (e->goto_block) = true;
}
- /* Remove unmarked vars and clear used flag. */
- for (cell = &cfun->unexpanded_var_list; *cell; )
+ cfun->has_local_explicit_reg_vars = false;
+
+ /* Remove unmarked local vars from local_decls. */
+ for (cell = &cfun->local_decls; *cell; )
{
tree var = TREE_VALUE (*cell);
&& (!(ann = var_ann (var))
|| !ann->used))
{
- *cell = TREE_CHAIN (*cell);
- continue;
+ if (is_global_var (var))
+ {
+ if (global_unused_vars == NULL)
+ global_unused_vars = BITMAP_ALLOC (NULL);
+ bitmap_set_bit (global_unused_vars, DECL_UID (var));
+ }
+ else
+ {
+ *cell = TREE_CHAIN (*cell);
+ continue;
+ }
}
+ else if (TREE_CODE (var) == VAR_DECL
+ && DECL_HARD_REGISTER (var)
+ && !is_global_var (var))
+ cfun->has_local_explicit_reg_vars = true;
cell = &TREE_CHAIN (*cell);
}
+ /* Remove unmarked global vars from local_decls. */
+ if (global_unused_vars != NULL)
+ {
+ for (t = cfun->local_decls; t; t = TREE_CHAIN (t))
+ {
+ tree var = TREE_VALUE (t);
+
+ if (TREE_CODE (var) == VAR_DECL
+ && is_global_var (var)
+ && (ann = var_ann (var)) != NULL
+ && ann->used)
+ mark_all_vars_used (&DECL_INITIAL (var), global_unused_vars);
+ }
+
+ for (cell = &cfun->local_decls; *cell; )
+ {
+ tree var = TREE_VALUE (*cell);
+
+ if (TREE_CODE (var) == VAR_DECL
+ && is_global_var (var)
+ && bitmap_bit_p (global_unused_vars, DECL_UID (var))
+ && (optimize || DECL_ARTIFICIAL (var)))
+ *cell = TREE_CHAIN (*cell);
+ else
+ cell = &TREE_CHAIN (*cell);
+ }
+ BITMAP_FREE (global_unused_vars);
+ }
+
/* Remove unused variables from REFERENCED_VARs. As a special
exception keep the variables that are believed to be aliased.
Those can't be easily removed from the alias sets and operand
&& TREE_CODE (t) != RESULT_DECL
&& !(ann = var_ann (t))->used
&& !ann->symbol_mem_tag
- && !TREE_ADDRESSABLE (t))
+ && !TREE_ADDRESSABLE (t)
+ && (optimize || DECL_ARTIFICIAL (t)))
remove_referenced_var (t);
- remove_unused_scope_block_p (DECL_INITIAL (current_function_decl));
+ if (optimize)
+ remove_unused_scope_block_p (DECL_INITIAL (current_function_decl));
}
set_var_live_on_entry (tree ssa_name, tree_live_info_p live)
{
int p;
- tree stmt;
+ gimple stmt;
use_operand_p use;
basic_block def_bb = NULL;
imm_use_iterator imm_iter;
stmt = SSA_NAME_DEF_STMT (ssa_name);
if (stmt)
{
- def_bb = bb_for_stmt (stmt);
+ def_bb = gimple_bb (stmt);
/* Mark defs in liveout bitmap temporarily. */
if (def_bb)
bitmap_set_bit (live->liveout[def_bb->index], p);
add it to the list of live on entry blocks. */
FOR_EACH_IMM_USE_FAST (use, imm_iter, ssa_name)
{
- tree use_stmt = USE_STMT (use);
+ gimple use_stmt = USE_STMT (use);
basic_block add_block = NULL;
- if (TREE_CODE (use_stmt) == PHI_NODE)
+ if (gimple_code (use_stmt) == GIMPLE_PHI)
{
/* Uses in PHI's are considered to be live at exit of the SRC block
as this is where a copy would be inserted. Check to see if it is
defined in that block, or whether its live on entry. */
int index = PHI_ARG_INDEX_FROM_USE (use);
- edge e = PHI_ARG_EDGE (use_stmt, index);
+ edge e = gimple_phi_arg_edge (use_stmt, index);
if (e->src != ENTRY_BLOCK_PTR)
{
if (e->src != def_bb)
else
{
/* If its not defined in this block, its live on entry. */
- basic_block use_bb = bb_for_stmt (use_stmt);
+ basic_block use_bb = gimple_bb (use_stmt);
if (use_bb != def_bb)
add_block = use_bb;
}
void
calculate_live_on_exit (tree_live_info_p liveinfo)
{
- unsigned i;
- int p;
- tree t, phi;
basic_block bb;
edge e;
edge_iterator ei;
/* Set all the live-on-exit bits for uses in PHIs. */
FOR_EACH_BB (bb)
{
+ gimple_stmt_iterator gsi;
+ size_t i;
+
/* Mark the PHI arguments which are live on exit to the pred block. */
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
- for (i = 0; i < (unsigned)PHI_NUM_ARGS (phi); i++)
- {
- t = PHI_ARG_DEF (phi, i);
- if (TREE_CODE (t) != SSA_NAME)
- continue;
- p = var_to_partition (liveinfo->map, t);
- if (p == NO_PARTITION)
- continue;
- e = PHI_ARG_EDGE (phi, i);
- if (e->src != ENTRY_BLOCK_PTR)
- bitmap_set_bit (liveinfo->liveout[e->src->index], p);
- }
+ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple phi = gsi_stmt (gsi);
+ for (i = 0; i < gimple_phi_num_args (phi); i++)
+ {
+ tree t = PHI_ARG_DEF (phi, i);
+ int p;
+
+ if (TREE_CODE (t) != SSA_NAME)
+ continue;
+
+ p = var_to_partition (liveinfo->map, t);
+ if (p == NO_PARTITION)
+ continue;
+ e = gimple_phi_arg_edge (phi, i);
+ if (e->src != ENTRY_BLOCK_PTR)
+ bitmap_set_bit (liveinfo->liveout[e->src->index], p);
+ }
+ }
/* Add each successors live on entry to this bock live on exit. */
FOR_EACH_EDGE (e, ei, bb->succs)
{
unsigned i;
tree var;
- tree phi, stmt;
+ gimple stmt;
basic_block bb;
edge e;
int num;
bitmap loe;
var = partition_to_var (map, i);
stmt = SSA_NAME_DEF_STMT (var);
- tmp = bb_for_stmt (stmt);
+ tmp = gimple_bb (stmt);
d = gimple_default_def (cfun, SSA_NAME_VAR (var));
loe = live_on_entry (live, e->dest);
if (loe && bitmap_bit_p (loe, i))
{
- if (!IS_EMPTY_STMT (stmt))
+ if (!gimple_nop_p (stmt))
{
num++;
print_generic_expr (stderr, var, TDF_SLIM);
if (tmp)
fprintf (stderr, " in BB%d, ", tmp->index);
fprintf (stderr, "by:\n");
- print_generic_expr (stderr, stmt, TDF_SLIM);
+ print_gimple_stmt (stderr, stmt, 0, TDF_SLIM);
fprintf (stderr, "\nIt is also live-on-entry to entry BB %d",
entry_block);
fprintf (stderr, " So it appears to have multiple defs.\n");
{
num++;
print_generic_expr (stderr, var, TDF_SLIM);
- fprintf (stderr, " is live-on-entry to BB%d ",entry_block);
+ fprintf (stderr, " is live-on-entry to BB%d ",
+ entry_block);
if (d)
{
fprintf (stderr, " but is not the default def of ");
{
/* The only way this var shouldn't be marked live on entry is
if it occurs in a PHI argument of the block. */
- int z, ok = 0;
- for (phi = phi_nodes (e->dest);
- phi && !ok;
- phi = PHI_CHAIN (phi))
+ size_t z;
+ bool ok = false;
+ gimple_stmt_iterator gsi;
+ for (gsi = gsi_start_phis (e->dest);
+ !gsi_end_p (gsi) && !ok;
+ gsi_next (&gsi))
{
- for (z = 0; z < PHI_NUM_ARGS (phi); z++)
- if (var == PHI_ARG_DEF (phi, z))
+ gimple phi = gsi_stmt (gsi);
+ for (z = 0; z < gimple_phi_num_args (phi); z++)
+ if (var == gimple_phi_arg_def (phi, z))
{
- ok = 1;
+ ok = true;
break;
}
}
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