/* Miscellaneous SSA utility functions.
- Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009
+ Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
Free Software Foundation, Inc.
This file is part of GCC.
#include "tm.h"
#include "tree.h"
#include "flags.h"
-#include "rtl.h"
#include "tm_p.h"
#include "target.h"
#include "ggc.h"
#include "langhooks.h"
-#include "hard-reg-set.h"
#include "basic-block.h"
#include "output.h"
#include "expr.h"
#include "function.h"
#include "diagnostic.h"
+#include "tree-pretty-print.h"
+#include "gimple-pretty-print.h"
#include "bitmap.h"
#include "pointer-set.h"
#include "tree-flow.h"
#include "gimple.h"
#include "tree-inline.h"
-#include "varray.h"
#include "timevar.h"
#include "hashtab.h"
#include "tree-dump.h"
{
struct walk_stmt_info *wi = (struct walk_stmt_info *) data_;
- if (wi->is_lhs)
+ if (wi && wi->is_lhs)
return NULL_TREE;
if (TREE_CODE (*tp) == SSA_NAME)
if (!MAY_HAVE_DEBUG_STMTS)
return;
- /* First of all, check whether there are debug stmts that reference
- this variable and, if there are, decide whether we should use a
- debug temp. */
+ /* If this name has already been registered for replacement, do nothing
+ as anything that uses this name isn't in SSA form. */
+ if (name_registered_for_update_p (var))
+ return;
+
+ /* Check whether there are debug stmts that reference this variable and,
+ if there are, decide whether we should use a debug temp. */
FOR_EACH_IMM_USE_FAST (use_p, imm_iter, var)
{
stmt = USE_STMT (use_p);
/* If we didn't get an insertion point, and the stmt has already
been removed, we won't be able to insert the debug bind stmt, so
we'll have to drop debug information. */
- if (is_gimple_assign (def_stmt))
+ if (gimple_code (def_stmt) == GIMPLE_PHI)
+ {
+ value = degenerate_phi_result (def_stmt);
+ if (value && walk_tree (&value, find_released_ssa_name, NULL, NULL))
+ value = NULL;
+ }
+ else if (is_gimple_assign (def_stmt))
{
bool no_value = false;
at the expense of duplication of expressions. */
if (CONSTANT_CLASS_P (value)
+ || gimple_code (def_stmt) == GIMPLE_PHI
|| (usecount == 1
&& (!gimple_assign_single_p (def_stmt)
|| is_gimple_min_invariant (value)))
stmt = gsi_stmt (*gsi);
- FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, op_iter, SSA_OP_DEF)
+ FOR_EACH_PHI_OR_STMT_DEF (def_p, stmt, op_iter, SSA_OP_DEF)
{
tree var = DEF_FROM_PTR (def_p);
err = true;
}
- /* Make sure the use is in an appropriate list by checking the previous
+ /* Make sure the use is in an appropriate list by checking the previous
element to make sure it's the same. */
if (use_p->prev == NULL)
{
free_dominance_info (CDI_DOMINATORS);
else
set_dom_info_availability (CDI_DOMINATORS, orig_dom_state);
-
+
BITMAP_FREE (names_defined_in_bb);
timevar_pop (TV_TREE_SSA_VERIFY);
return;
init_tree_ssa (struct function *fn)
{
fn->gimple_df = GGC_CNEW (struct gimple_df);
- fn->gimple_df->referenced_vars = htab_create_ggc (20, uid_decl_map_hash,
+ fn->gimple_df->referenced_vars = htab_create_ggc (20, uid_decl_map_hash,
uid_decl_map_eq, NULL);
- fn->gimple_df->default_defs = htab_create_ggc (20, uid_ssaname_map_hash,
+ fn->gimple_df->default_defs = htab_create_ggc (20, uid_ssaname_map_hash,
uid_ssaname_map_eq, NULL);
pt_solution_reset (&fn->gimple_df->escaped);
- pt_solution_reset (&fn->gimple_df->callused);
init_ssanames (fn, 0);
init_phinodes ();
}
{
if (is_global_var (var))
continue;
- if (var->base.ann)
- ggc_free (var->base.ann);
- var->base.ann = NULL;
+ if (var_ann (var))
+ {
+ ggc_free (var_ann (var));
+ *DECL_VAR_ANN_PTR (var) = NULL;
+ }
}
htab_delete (gimple_referenced_vars (cfun));
cfun->gimple_df->referenced_vars = NULL;
htab_delete (cfun->gimple_df->default_defs);
cfun->gimple_df->default_defs = NULL;
pt_solution_reset (&cfun->gimple_df->escaped);
- pt_solution_reset (&cfun->gimple_df->callused);
if (cfun->gimple_df->decls_to_pointers != NULL)
pointer_map_destroy (cfun->gimple_df->decls_to_pointers);
cfun->gimple_df->decls_to_pointers = NULL;
else if (AGGREGATE_TYPE_P (inner_type)
&& TREE_CODE (inner_type) == TREE_CODE (outer_type))
return false;
-
+
return false;
}
/* Internal helper for walk_use_def_chains. VAR, FN and DATA are as
described in walk_use_def_chains.
-
+
VISITED is a pointer set used to mark visited SSA_NAMEs to avoid
infinite loops. We used to have a bitmap for this to just mark
SSA versions we had visited. But non-sparse bitmaps are way too
if (fn (gimple_phi_arg_def (def_stmt, i), def_stmt, data))
return true;
}
-
+
return false;
}
-
+
/* Walk use-def chains starting at the SSA variable VAR. Call
arguments: VAR, its defining statement (DEF_STMT) and a generic
pointer to whatever state information that FN may want to maintain
(DATA). FN is able to stop the walk by returning true, otherwise
- in order to continue the walk, FN should return false.
+ in order to continue the walk, FN should return false.
Note, that if DEF_STMT is a PHI node, the semantics are slightly
different. The first argument to FN is no longer the original
}
\f
-/* Return true if T, an SSA_NAME, has an undefined value. */
-
-bool
-ssa_undefined_value_p (tree t)
-{
- tree var = SSA_NAME_VAR (t);
-
- /* Parameters get their initial value from the function entry. */
- if (TREE_CODE (var) == PARM_DECL)
- return false;
-
- /* Hard register variables get their initial value from the ether. */
- if (TREE_CODE (var) == VAR_DECL && DECL_HARD_REGISTER (var))
- return false;
-
- /* The value is undefined iff its definition statement is empty. */
- return gimple_nop_p (SSA_NAME_DEF_STMT (t));
-}
-
/* Emit warnings for uninitialized variables. This is done in two passes.
The first pass notices real uses of SSA names with undefined values.
/* Emit a warning for T, an SSA_NAME, being uninitialized. The exact
warning text is in MSGID and LOCUS may contain a location or be null. */
-static void
+void
warn_uninit (tree t, const char *gmsgid, void *data)
{
tree var = SSA_NAME_VAR (t);
/* Do not warn if it can be initialized outside this module. */
if (is_global_var (var))
return;
-
+
location = (context != NULL && gimple_has_location (context))
? gimple_location (context)
: DECL_SOURCE_LOCATION (var);
use_operand_p vuse;
tree op;
- /* If there is not gimple stmt,
+ /* If there is not gimple stmt,
or alias information has not been computed,
then we cannot check VUSE ops. */
if (data->stmt == NULL)
return NULL_TREE;
op = USE_FROM_PTR (vuse);
- if (t != SSA_NAME_VAR (op)
+ if (t != SSA_NAME_VAR (op)
|| !SSA_NAME_IS_DEFAULT_DEF (op))
return NULL_TREE;
/* If this is a VUSE of t and it is the default definition,
return NULL_TREE;
}
-/* Look for inputs to PHI that are SSA_NAMEs that have empty definitions
- and warn about them. */
-
-static void
-warn_uninitialized_phi (gimple phi)
-{
- size_t i, n = gimple_phi_num_args (phi);
-
- /* Don't look at memory tags. */
- if (!is_gimple_reg (gimple_phi_result (phi)))
- return;
-
- for (i = 0; i < n; ++i)
- {
- tree op = gimple_phi_arg_def (phi, i);
- if (TREE_CODE (op) == SSA_NAME)
- warn_uninit (op, "%qD may be used uninitialized in this function",
- NULL);
- }
-}
-
-static unsigned int
+unsigned int
warn_uninitialized_vars (bool warn_possibly_uninitialized)
{
gimple_stmt_iterator gsi;
data.warn_possibly_uninitialized = warn_possibly_uninitialized;
- calculate_dominance_info (CDI_POST_DOMINATORS);
FOR_EACH_BB (bb)
{
}
}
- /* Post-dominator information can not be reliably updated. Free it
- after the use. */
-
- free_dominance_info (CDI_POST_DOMINATORS);
return 0;
}
as possible, thus don't do it here. However, without
optimization we need to warn here about "may be uninitialized".
*/
- warn_uninitialized_vars (/*warn_possibly_uninitialized=*/!optimize);
- return 0;
-}
-
-static unsigned int
-execute_late_warn_uninitialized (void)
-{
- basic_block bb;
- gimple_stmt_iterator gsi;
+ calculate_dominance_info (CDI_POST_DOMINATORS);
- /* Re-do the plain uninitialized variable check, as optimization may have
- straightened control flow. Do this first so that we don't accidentally
- get a "may be" warning when we'd have seen an "is" warning later. */
- warn_uninitialized_vars (/*warn_possibly_uninitialized=*/1);
+ warn_uninitialized_vars (/*warn_possibly_uninitialized=*/!optimize);
- FOR_EACH_BB (bb)
- for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
- warn_uninitialized_phi (gsi_stmt (gsi));
+ /* Post-dominator information can not be reliably updated. Free it
+ after the use. */
+ free_dominance_info (CDI_POST_DOMINATORS);
return 0;
}
}
};
-struct gimple_opt_pass pass_late_warn_uninitialized =
-{
- {
- GIMPLE_PASS,
- "*late_warn_uninitialized", /* name */
- gate_warn_uninitialized, /* gate */
- execute_late_warn_uninitialized, /* execute */
- NULL, /* sub */
- NULL, /* next */
- 0, /* static_pass_number */
- TV_NONE, /* tv_id */
- PROP_ssa, /* properties_required */
- 0, /* properties_provided */
- 0, /* properties_destroyed */
- 0, /* todo_flags_start */
- 0 /* todo_flags_finish */
- }
-};
-
/* Compute TREE_ADDRESSABLE and DECL_GIMPLE_REG_P for local variables. */
void
if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL)
{
tree lhs = gimple_get_lhs (stmt);
-
+
/* We may not rewrite TMR_SYMBOL to SSA. */
if (lhs && TREE_CODE (lhs) == TARGET_MEM_REF
&& TMR_SYMBOL (lhs))
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