/* Liveness for SSA trees.
- Copyright (C) 2003, 2004, 2005, 2007, 2008 Free Software Foundation,
+ Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009 Free Software Foundation,
Inc.
Contributed by Andrew MacLeod <amacleod@redhat.com>
/* 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)
+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;
next = &TREE_CHAIN (*t);
/* Debug info of nested function refers to the block of the
- function. */
+ function. We might stil call it even if all statements
+ of function it was nested into was elliminated.
+
+ TODO: We can actually look into cgraph to see if function
+ will be output to file. */
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.
/* 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. */
+ a lot of memory.
+
+ For sake of -g3, we keep around those vars but we don't count this as
+ use of block, so innermost block with no used vars and no instructions
+ can be considered dead. We only want to keep around blocks user can
+ breakpoint into and ask about value of optimized out variables.
+
+ Similarly we need to keep around types at least until all variables of
+ all nested blocks are gone. We track no information on whether given
+ type is used or not. */
+
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);
{
tree next = BLOCK_CHAIN (*t);
tree supercontext = BLOCK_SUPERCONTEXT (*t);
+
*t = BLOCK_SUBBLOCKS (*t);
- gcc_assert (!BLOCK_CHAIN (*t));
+ while (BLOCK_CHAIN (*t))
+ {
+ BLOCK_SUPERCONTEXT (*t) = supercontext;
+ t = &BLOCK_CHAIN (*t);
+ }
BLOCK_CHAIN (*t) = next;
BLOCK_SUPERCONTEXT (*t) = supercontext;
t = &BLOCK_CHAIN (*t);
nsubblocks ++;
}
else
- {
- gcc_assert (!BLOCK_VARS (*t));
- *t = BLOCK_CHAIN (*t);
- }
+ *t = BLOCK_CHAIN (*t);
}
else
{
t = &BLOCK_CHAIN (*t);
nsubblocks ++;
}
+
+
+ if (!unused)
+ ;
/* Outer scope is always used. */
- if (!BLOCK_SUPERCONTEXT (scope)
- || TREE_CODE (BLOCK_SUPERCONTEXT (scope)) == FUNCTION_DECL)
+ else if (!BLOCK_SUPERCONTEXT (scope)
+ || TREE_CODE (BLOCK_SUPERCONTEXT (scope)) == FUNCTION_DECL)
unused = false;
- /* If there are more than one live subblocks, it is used. */
- else if (nsubblocks > 1)
+ /* Innermost blocks with no live variables nor statements can be always
+ eliminated. */
+ else if (!nsubblocks)
+ ;
+ /* If there are live subblocks and we still have some unused variables
+ or types declared, we must keep them.
+ Before inliing we must not depend on debug info verbosity to keep
+ DECL_UIDs stable. */
+ else if (!cfun->after_inlining && BLOCK_VARS (scope))
unused = false;
- /* When there is only one subblock, see if it is just wrapper we can
- ignore. Wrappers are not declaring any variables and not changing
- abstract origin. */
- else if (nsubblocks == 1
- && (BLOCK_VARS (scope)
- || ((debug_info_level == DINFO_LEVEL_NORMAL
- || debug_info_level == DINFO_LEVEL_VERBOSE)
- && ((BLOCK_ABSTRACT_ORIGIN (scope)
- != BLOCK_ABSTRACT_ORIGIN (BLOCK_SUPERCONTEXT (scope)))))))
+ /* For terse debug info we can eliminate info on unused variables. */
+ else if (debug_info_level == DINFO_LEVEL_NONE
+ || debug_info_level == DINFO_LEVEL_TERSE)
+ ;
+ else if (BLOCK_VARS (scope) || BLOCK_NUM_NONLOCALIZED_VARS (scope))
unused = false;
+ /* See if this block is important for representation of inlined function.
+ Inlined functions are always represented by block with
+ block_ultimate_origin being set to FUNCTION_DECL and DECL_SOURCE_LOCATION
+ set... */
+ else if (inlined_function_outer_scope_p (scope))
+ unused = false;
+ else
+ /* Verfify that only blocks with source location set
+ are entry points to the inlined functions. */
+ gcc_assert (BLOCK_SOURCE_LOCATION (scope) == UNKNOWN_LOCATION);
return unused;
}
walk_tree (expr_p, mark_all_vars_used_1, data, NULL);
}
+/* Dump scope blocks. */
+
+static void
+dump_scope_block (FILE *file, int indent, tree scope, int flags)
+{
+ tree var, t;
+ unsigned int i;
+
+ fprintf (file, "\n%*s{ Scope block #%i%s%s",indent, "" , BLOCK_NUMBER (scope),
+ TREE_USED (scope) ? "" : " (unused)",
+ BLOCK_ABSTRACT (scope) ? " (abstract)": "");
+ if (BLOCK_SOURCE_LOCATION (scope) != UNKNOWN_LOCATION)
+ {
+ expanded_location s = expand_location (BLOCK_SOURCE_LOCATION (scope));
+ fprintf (file, " %s:%i", s.file, s.line);
+ }
+ if (BLOCK_ABSTRACT_ORIGIN (scope))
+ {
+ tree origin = block_ultimate_origin (scope);
+ if (origin)
+ {
+ fprintf (file, " Originating from :");
+ if (DECL_P (origin))
+ print_generic_decl (file, origin, flags);
+ else
+ fprintf (file, "#%i", BLOCK_NUMBER (origin));
+ }
+ }
+ fprintf (file, " \n");
+ for (var = BLOCK_VARS (scope); var; var = TREE_CHAIN (var))
+ {
+ bool used = false;
+ var_ann_t ann;
+
+ if ((ann = var_ann (var))
+ && ann->used)
+ used = true;
+
+ fprintf (file, "%*s",indent, "");
+ print_generic_decl (file, var, flags);
+ fprintf (file, "%s\n", used ? "" : " (unused)");
+ }
+ for (i = 0; i < BLOCK_NUM_NONLOCALIZED_VARS (scope); i++)
+ {
+ fprintf (file, "%*s",indent, "");
+ print_generic_decl (file, BLOCK_NONLOCALIZED_VAR (scope, i),
+ flags);
+ fprintf (file, " (nonlocalized)\n");
+ }
+ for (t = BLOCK_SUBBLOCKS (scope); t ; t = BLOCK_CHAIN (t))
+ dump_scope_block (file, indent + 2, t, flags);
+ fprintf (file, "\n%*s}\n",indent, "");
+}
+
+void
+dump_scope_blocks (FILE *file, int flags)
+{
+ dump_scope_block (file, 0, DECL_INITIAL (current_function_decl), flags);
+}
/* Remove local variables that are not referenced in the IL. */
bitmap global_unused_vars = NULL;
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), NULL);
+ 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);
+ def = gimple_phi_result (phi);
mark_all_vars_used (&def, NULL);
FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_ALL_USES)
mark_all_vars_used (&arg, NULL);
}
}
+
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (e->goto_locus)
+ TREE_USED (e->goto_block) = true;
}
+ cfun->has_local_explicit_reg_vars = false;
+
/* Remove unmarked local vars from local_decls. */
for (cell = &cfun->local_decls; *cell; )
{
if (TREE_CODE (var) != FUNCTION_DECL
&& (!(ann = var_ann (var))
- || !ann->used))
+ || !ann->used)
+ && (optimize || DECL_ARTIFICIAL (var)))
{
if (is_global_var (var))
{
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);
}
pass is performed. */
FOR_EACH_REFERENCED_VAR (t, rvi)
if (!is_global_var (t)
- && !MTAG_P (t)
&& TREE_CODE (t) != PARM_DECL
&& 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 (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Scope blocks after cleanups:\n");
+ dump_scope_blocks (dump_file, dump_flags);
+ }
}
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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