/* Miscellaneous SSA utility functions.
- Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
+ 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 2, or (at your option)
+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,
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 COPYING. If not, write to
-the Free Software Foundation, 51 Franklin Street, Fifth Floor,
-Boston, MA 02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#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 "tree-gimple.h"
+#include "gimple.h"
#include "tree-inline.h"
-#include "varray.h"
#include "timevar.h"
#include "hashtab.h"
#include "tree-dump.h"
#include "tree-pass.h"
-#include "toplev.h"
+#include "diagnostic-core.h"
+#include "cfgloop.h"
+
+/* Pointer map of variable mappings, keyed by edge. */
+static struct pointer_map_t *edge_var_maps;
+
+
+/* Add a mapping with PHI RESULT and PHI DEF associated with edge E. */
+
+void
+redirect_edge_var_map_add (edge e, tree result, tree def, source_location locus)
+{
+ void **slot;
+ edge_var_map_vector old_head, head;
+ edge_var_map new_node;
+
+ if (edge_var_maps == NULL)
+ edge_var_maps = pointer_map_create ();
+
+ slot = pointer_map_insert (edge_var_maps, e);
+ old_head = head = (edge_var_map_vector) *slot;
+ if (!head)
+ {
+ head = VEC_alloc (edge_var_map, heap, 5);
+ *slot = head;
+ }
+ new_node.def = def;
+ new_node.result = result;
+ new_node.locus = locus;
+
+ VEC_safe_push (edge_var_map, heap, head, &new_node);
+ if (old_head != head)
+ {
+ /* The push did some reallocation. Update the pointer map. */
+ *slot = head;
+ }
+}
+
+
+/* Clear the var mappings in edge E. */
+
+void
+redirect_edge_var_map_clear (edge e)
+{
+ void **slot;
+ edge_var_map_vector head;
+
+ if (!edge_var_maps)
+ return;
+
+ slot = pointer_map_contains (edge_var_maps, e);
+
+ if (slot)
+ {
+ head = (edge_var_map_vector) *slot;
+ VEC_free (edge_var_map, heap, head);
+ *slot = NULL;
+ }
+}
+
+
+/* Duplicate the redirected var mappings in OLDE in NEWE.
+
+ Since we can't remove a mapping, let's just duplicate it. This assumes a
+ pointer_map can have multiple edges mapping to the same var_map (many to
+ one mapping), since we don't remove the previous mappings. */
+
+void
+redirect_edge_var_map_dup (edge newe, edge olde)
+{
+ void **new_slot, **old_slot;
+ edge_var_map_vector head;
+
+ if (!edge_var_maps)
+ return;
+
+ new_slot = pointer_map_insert (edge_var_maps, newe);
+ old_slot = pointer_map_contains (edge_var_maps, olde);
+ if (!old_slot)
+ return;
+ head = (edge_var_map_vector) *old_slot;
+
+ if (head)
+ *new_slot = VEC_copy (edge_var_map, heap, head);
+ else
+ *new_slot = VEC_alloc (edge_var_map, heap, 5);
+}
+
+
+/* Return the variable mappings for a given edge. If there is none, return
+ NULL. */
+
+edge_var_map_vector
+redirect_edge_var_map_vector (edge e)
+{
+ void **slot;
+
+ /* Hey, what kind of idiot would... you'd be surprised. */
+ if (!edge_var_maps)
+ return NULL;
+
+ slot = pointer_map_contains (edge_var_maps, e);
+ if (!slot)
+ return NULL;
+
+ return (edge_var_map_vector) *slot;
+}
+
+/* Used by redirect_edge_var_map_destroy to free all memory. */
+
+static bool
+free_var_map_entry (const void *key ATTRIBUTE_UNUSED,
+ void **value,
+ void *data ATTRIBUTE_UNUSED)
+{
+ edge_var_map_vector head = (edge_var_map_vector) *value;
+ VEC_free (edge_var_map, heap, head);
+ return true;
+}
+
+/* Clear the edge variable mappings. */
+
+void
+redirect_edge_var_map_destroy (void)
+{
+ if (edge_var_maps)
+ {
+ pointer_map_traverse (edge_var_maps, free_var_map_entry, NULL);
+ pointer_map_destroy (edge_var_maps);
+ edge_var_maps = NULL;
+ }
+}
+
/* Remove the corresponding arguments from the PHI nodes in E's
destination block and redirect it to DEST. Return redirected edge.
- The list of removed arguments is stored in PENDING_STMT (e). */
+ The list of removed arguments is stored in a vector accessed
+ through edge_var_maps. */
edge
ssa_redirect_edge (edge e, basic_block dest)
{
- tree phi;
- tree list = NULL, *last = &list;
- tree src, dst, node;
+ gimple_stmt_iterator gsi;
+ gimple phi;
+
+ redirect_edge_var_map_clear (e);
/* Remove the appropriate PHI arguments in E's destination block. */
- for (phi = phi_nodes (e->dest); phi; phi = PHI_CHAIN (phi))
+ for (gsi = gsi_start_phis (e->dest); !gsi_end_p (gsi); gsi_next (&gsi))
{
- if (PHI_ARG_DEF (phi, e->dest_idx) == NULL_TREE)
+ tree def;
+ source_location locus ;
+
+ phi = gsi_stmt (gsi);
+ def = gimple_phi_arg_def (phi, e->dest_idx);
+ locus = gimple_phi_arg_location (phi, e->dest_idx);
+
+ if (def == NULL_TREE)
continue;
- src = PHI_ARG_DEF (phi, e->dest_idx);
- dst = PHI_RESULT (phi);
- node = build_tree_list (dst, src);
- *last = node;
- last = &TREE_CHAIN (node);
+ redirect_edge_var_map_add (e, gimple_phi_result (phi), def, locus);
}
e = redirect_edge_succ_nodup (e, dest);
- PENDING_STMT (e) = list;
return e;
}
-/* Add PHI arguments queued in PENDINT_STMT list on edge E to edge
+
+/* Add PHI arguments queued in PENDING_STMT list on edge E to edge
E->dest. */
void
flush_pending_stmts (edge e)
{
- tree phi, arg;
+ gimple phi;
+ edge_var_map_vector v;
+ edge_var_map *vm;
+ int i;
+ gimple_stmt_iterator gsi;
+
+ v = redirect_edge_var_map_vector (e);
+ if (!v)
+ return;
+
+ for (gsi = gsi_start_phis (e->dest), i = 0;
+ !gsi_end_p (gsi) && VEC_iterate (edge_var_map, v, i, vm);
+ gsi_next (&gsi), i++)
+ {
+ tree def;
+
+ phi = gsi_stmt (gsi);
+ def = redirect_edge_var_map_def (vm);
+ add_phi_arg (phi, def, e, redirect_edge_var_map_location (vm));
+ }
+
+ redirect_edge_var_map_clear (e);
+}
+
+/* Given a tree for an expression for which we might want to emit
+ locations or values in debug information (generally a variable, but
+ we might deal with other kinds of trees in the future), return the
+ tree that should be used as the variable of a DEBUG_BIND STMT or
+ VAR_LOCATION INSN or NOTE. Return NULL if VAR is not to be tracked. */
+
+tree
+target_for_debug_bind (tree var)
+{
+ if (!MAY_HAVE_DEBUG_STMTS)
+ return NULL_TREE;
+
+ if (TREE_CODE (var) != VAR_DECL
+ && TREE_CODE (var) != PARM_DECL)
+ return NULL_TREE;
+
+ if (DECL_HAS_VALUE_EXPR_P (var))
+ return target_for_debug_bind (DECL_VALUE_EXPR (var));
+
+ if (DECL_IGNORED_P (var))
+ return NULL_TREE;
+
+ if (!is_gimple_reg (var))
+ {
+ if (is_gimple_reg_type (TREE_TYPE (var))
+ && referenced_var_lookup (cfun, DECL_UID (var)) == NULL_TREE)
+ return var;
+ return NULL_TREE;
+ }
+
+ return var;
+}
+
+/* Called via walk_tree, look for SSA_NAMEs that have already been
+ released. */
+
+static tree
+find_released_ssa_name (tree *tp, int *walk_subtrees, void *data_)
+{
+ struct walk_stmt_info *wi = (struct walk_stmt_info *) data_;
+
+ if (wi && wi->is_lhs)
+ return NULL_TREE;
+
+ if (TREE_CODE (*tp) == SSA_NAME)
+ {
+ if (SSA_NAME_IN_FREE_LIST (*tp))
+ return *tp;
+
+ *walk_subtrees = 0;
+ }
+ else if (IS_TYPE_OR_DECL_P (*tp))
+ *walk_subtrees = 0;
+
+ return NULL_TREE;
+}
+
+/* Insert a DEBUG BIND stmt before the DEF of VAR if VAR is referenced
+ by other DEBUG stmts, and replace uses of the DEF with the
+ newly-created debug temp. */
+
+void
+insert_debug_temp_for_var_def (gimple_stmt_iterator *gsi, tree var)
+{
+ imm_use_iterator imm_iter;
+ use_operand_p use_p;
+ gimple stmt;
+ gimple def_stmt = NULL;
+ int usecount = 0;
+ tree value = NULL;
+
+ if (!MAY_HAVE_DEBUG_STMTS)
+ return;
+
+ /* 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 (!gimple_debug_bind_p (stmt))
+ continue;
+
+ if (usecount++)
+ break;
+
+ if (gimple_debug_bind_get_value (stmt) != var)
+ {
+ /* Count this as an additional use, so as to make sure we
+ use a temp unless VAR's definition has a SINGLE_RHS that
+ can be shared. */
+ usecount++;
+ break;
+ }
+ }
+
+ if (!usecount)
+ return;
+
+ if (gsi)
+ def_stmt = gsi_stmt (*gsi);
+ else
+ def_stmt = SSA_NAME_DEF_STMT (var);
+
+ /* 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 (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;
+ /* error_mark_node is what fixup_noreturn_call changes PHI arguments
+ to. */
+ else if (value == error_mark_node)
+ value = NULL;
+ }
+ else if (is_gimple_assign (def_stmt))
+ {
+ bool no_value = false;
+
+ if (!dom_info_available_p (CDI_DOMINATORS))
+ {
+ struct walk_stmt_info wi;
+
+ memset (&wi, 0, sizeof (wi));
+
+ /* When removing blocks without following reverse dominance
+ order, we may sometimes encounter SSA_NAMEs that have
+ already been released, referenced in other SSA_DEFs that
+ we're about to release. Consider:
+
+ <bb X>:
+ v_1 = foo;
+
+ <bb Y>:
+ w_2 = v_1 + bar;
+ # DEBUG w => w_2
+
+ If we deleted BB X first, propagating the value of w_2
+ won't do us any good. It's too late to recover their
+ original definition of v_1: when it was deleted, it was
+ only referenced in other DEFs, it couldn't possibly know
+ it should have been retained, and propagating every
+ single DEF just in case it might have to be propagated
+ into a DEBUG STMT would probably be too wasteful.
+
+ When dominator information is not readily available, we
+ check for and accept some loss of debug information. But
+ if it is available, there's no excuse for us to remove
+ blocks in the wrong order, so we don't even check for
+ dead SSA NAMEs. SSA verification shall catch any
+ errors. */
+ if ((!gsi && !gimple_bb (def_stmt))
+ || walk_gimple_op (def_stmt, find_released_ssa_name, &wi))
+ no_value = true;
+ }
+
+ if (!no_value)
+ value = gimple_assign_rhs_to_tree (def_stmt);
+ }
+
+ if (value)
+ {
+ /* If there's a single use of VAR, and VAR is the entire debug
+ expression (usecount would have been incremented again
+ otherwise), and the definition involves only constants and
+ SSA names, then we can propagate VALUE into this single use,
+ avoiding the temp.
+
+ We can also avoid using a temp if VALUE can be shared and
+ propagated into all uses, without generating expressions that
+ wouldn't be valid gimple RHSs.
+
+ Other cases that would require unsharing or non-gimple RHSs
+ are deferred to a debug temp, although we could avoid temps
+ 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)))
+ || is_gimple_reg (value))
+ value = unshare_expr (value);
+ else
+ {
+ gimple def_temp;
+ tree vexpr = make_node (DEBUG_EXPR_DECL);
+
+ def_temp = gimple_build_debug_bind (vexpr,
+ unshare_expr (value),
+ def_stmt);
+
+ DECL_ARTIFICIAL (vexpr) = 1;
+ TREE_TYPE (vexpr) = TREE_TYPE (value);
+ if (DECL_P (value))
+ DECL_MODE (vexpr) = DECL_MODE (value);
+ else
+ DECL_MODE (vexpr) = TYPE_MODE (TREE_TYPE (value));
+
+ if (gsi)
+ gsi_insert_before (gsi, def_temp, GSI_SAME_STMT);
+ else
+ {
+ gimple_stmt_iterator ngsi = gsi_for_stmt (def_stmt);
+ gsi_insert_before (&ngsi, def_temp, GSI_SAME_STMT);
+ }
+
+ value = vexpr;
+ }
+ }
+
+ FOR_EACH_IMM_USE_STMT (stmt, imm_iter, var)
+ {
+ if (!gimple_debug_bind_p (stmt))
+ continue;
+
+ if (value)
+ {
+ FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
+ /* unshare_expr is not needed here. vexpr is either a
+ SINGLE_RHS, that can be safely shared, some other RHS
+ that was unshared when we found it had a single debug
+ use, or a DEBUG_EXPR_DECL, that can be safely
+ shared. */
+ SET_USE (use_p, value);
+ /* If we didn't replace uses with a debug decl fold the
+ resulting expression. Otherwise we end up with invalid IL. */
+ if (TREE_CODE (value) != DEBUG_EXPR_DECL)
+ {
+ gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
+ fold_stmt_inplace (&gsi);
+ }
+ }
+ else
+ gimple_debug_bind_reset_value (stmt);
+
+ update_stmt (stmt);
+ }
+}
+
+
+/* Insert a DEBUG BIND stmt before STMT for each DEF referenced by
+ other DEBUG stmts, and replace uses of the DEF with the
+ newly-created debug temp. */
+
+void
+insert_debug_temps_for_defs (gimple_stmt_iterator *gsi)
+{
+ gimple stmt;
+ ssa_op_iter op_iter;
+ def_operand_p def_p;
+
+ if (!MAY_HAVE_DEBUG_STMTS)
+ return;
+
+ stmt = gsi_stmt (*gsi);
+
+ FOR_EACH_PHI_OR_STMT_DEF (def_p, stmt, op_iter, SSA_OP_DEF)
+ {
+ tree var = DEF_FROM_PTR (def_p);
+
+ if (TREE_CODE (var) != SSA_NAME)
+ continue;
+
+ insert_debug_temp_for_var_def (gsi, var);
+ }
+}
+
+/* Reset all debug stmts that use SSA_NAME(s) defined in STMT. */
+
+void
+reset_debug_uses (gimple stmt)
+{
+ ssa_op_iter op_iter;
+ def_operand_p def_p;
+ imm_use_iterator imm_iter;
+ gimple use_stmt;
- if (!PENDING_STMT (e))
+ if (!MAY_HAVE_DEBUG_STMTS)
return;
- for (phi = phi_nodes (e->dest), arg = PENDING_STMT (e);
- phi;
- phi = PHI_CHAIN (phi), arg = TREE_CHAIN (arg))
+ FOR_EACH_PHI_OR_STMT_DEF (def_p, stmt, op_iter, SSA_OP_DEF)
{
- tree def = TREE_VALUE (arg);
- add_phi_arg (phi, def, e);
+ tree var = DEF_FROM_PTR (def_p);
+
+ if (TREE_CODE (var) != SSA_NAME)
+ continue;
+
+ FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, var)
+ {
+ if (!gimple_debug_bind_p (use_stmt))
+ continue;
+
+ gimple_debug_bind_reset_value (use_stmt);
+ update_stmt (use_stmt);
+ }
}
+}
+
+/* Delete SSA DEFs for SSA versions in the TOREMOVE bitmap, removing
+ dominated stmts before their dominators, so that release_ssa_defs
+ stands a chance of propagating DEFs into debug bind stmts. */
- PENDING_STMT (e) = NULL;
+void
+release_defs_bitset (bitmap toremove)
+{
+ unsigned j;
+ bitmap_iterator bi;
+
+ /* Performing a topological sort is probably overkill, this will
+ most likely run in slightly superlinear time, rather than the
+ pathological quadratic worst case. */
+ while (!bitmap_empty_p (toremove))
+ EXECUTE_IF_SET_IN_BITMAP (toremove, 0, j, bi)
+ {
+ bool remove_now = true;
+ tree var = ssa_name (j);
+ gimple stmt;
+ imm_use_iterator uit;
+
+ FOR_EACH_IMM_USE_STMT (stmt, uit, var)
+ {
+ ssa_op_iter dit;
+ def_operand_p def_p;
+
+ /* We can't propagate PHI nodes into debug stmts. */
+ if (gimple_code (stmt) == GIMPLE_PHI
+ || is_gimple_debug (stmt))
+ continue;
+
+ /* If we find another definition to remove that uses
+ the one we're looking at, defer the removal of this
+ one, so that it can be propagated into debug stmts
+ after the other is. */
+ FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, dit, SSA_OP_DEF)
+ {
+ tree odef = DEF_FROM_PTR (def_p);
+
+ if (bitmap_bit_p (toremove, SSA_NAME_VERSION (odef)))
+ {
+ remove_now = false;
+ break;
+ }
+ }
+
+ if (!remove_now)
+ BREAK_FROM_IMM_USE_STMT (uit);
+ }
+
+ if (remove_now)
+ {
+ gimple def = SSA_NAME_DEF_STMT (var);
+ gimple_stmt_iterator gsi = gsi_for_stmt (def);
+
+ if (gimple_code (def) == GIMPLE_PHI)
+ remove_phi_node (&gsi, true);
+ else
+ {
+ gsi_remove (&gsi, true);
+ release_defs (def);
+ }
+
+ bitmap_clear_bit (toremove, j);
+ }
+ }
}
/* Return true if SSA_NAME is malformed and mark it visited.
return true;
}
+ if (is_virtual && SSA_NAME_VAR (ssa_name) != gimple_vop (cfun))
+ {
+ error ("virtual SSA name for non-VOP decl");
+ return true;
+ }
+
if (!is_virtual && !is_gimple_reg (ssa_name))
{
error ("found a real definition for a non-register");
return true;
}
- if (is_virtual && var_ann (SSA_NAME_VAR (ssa_name))
- && get_subvars_for_var (SSA_NAME_VAR (ssa_name)) != NULL)
+ if (SSA_NAME_IS_DEFAULT_DEF (ssa_name)
+ && !gimple_nop_p (SSA_NAME_DEF_STMT (ssa_name)))
{
- error ("found real variable when subvariables should have appeared");
+ error ("found a default name with a non-empty defining statement");
return true;
}
it means that the block in that array slot contains the
definition of SSA_NAME.
- IS_VIRTUAL is true if SSA_NAME is created by a V_MAY_DEF or a
- V_MUST_DEF. */
+ IS_VIRTUAL is true if SSA_NAME is created by a VDEF. */
static bool
verify_def (basic_block bb, basic_block *definition_block, tree ssa_name,
- tree stmt, bool is_virtual)
+ gimple stmt, bool is_virtual)
{
if (verify_ssa_name (ssa_name, is_virtual))
goto err;
+ if (TREE_CODE (SSA_NAME_VAR (ssa_name)) == RESULT_DECL
+ && DECL_BY_REFERENCE (SSA_NAME_VAR (ssa_name)))
+ {
+ error ("RESULT_DECL should be read only when DECL_BY_REFERENCE is set");
+ goto err;
+ }
+
if (definition_block[SSA_NAME_VERSION (ssa_name)])
{
error ("SSA_NAME created in two different blocks %i and %i",
{
error ("SSA_NAME_DEF_STMT is wrong");
fprintf (stderr, "Expected definition statement:\n");
- print_generic_stmt (stderr, SSA_NAME_DEF_STMT (ssa_name), TDF_VOPS);
+ print_gimple_stmt (stderr, SSA_NAME_DEF_STMT (ssa_name), 4, TDF_VOPS);
fprintf (stderr, "\nActual definition statement:\n");
- print_generic_stmt (stderr, stmt, TDF_VOPS);
+ print_gimple_stmt (stderr, stmt, 4, TDF_VOPS);
goto err;
}
fprintf (stderr, "while verifying SSA_NAME ");
print_generic_expr (stderr, ssa_name, 0);
fprintf (stderr, " in statement\n");
- print_generic_stmt (stderr, stmt, TDF_VOPS);
+ print_gimple_stmt (stderr, stmt, 4, TDF_VOPS);
return true;
}
is flowing through an abnormal edge (only used when checking PHI
arguments).
- IS_VIRTUAL is true if SSA_NAME is created by a V_MAY_DEF or a
- V_MUST_DEF.
-
If NAMES_DEFINED_IN_BB is not NULL, it contains a bitmap of ssa names
that are defined before STMT in basic block BB. */
static bool
verify_use (basic_block bb, basic_block def_bb, use_operand_p use_p,
- tree stmt, bool check_abnormal, bool is_virtual,
- bitmap names_defined_in_bb)
+ gimple stmt, bool check_abnormal, bitmap names_defined_in_bb)
{
bool err = false;
tree ssa_name = USE_FROM_PTR (use_p);
- err = verify_ssa_name (ssa_name, is_virtual);
-
if (!TREE_VISITED (ssa_name))
if (verify_imm_links (stderr, ssa_name))
err = true;
TREE_VISITED (ssa_name) = 1;
- if (IS_EMPTY_STMT (SSA_NAME_DEF_STMT (ssa_name))
- && default_def (SSA_NAME_VAR (ssa_name)) == ssa_name)
+ if (gimple_nop_p (SSA_NAME_DEF_STMT (ssa_name))
+ && SSA_NAME_IS_DEFAULT_DEF (ssa_name))
; /* Default definitions have empty statements. Nothing to do. */
else if (!def_bb)
{
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)
{
}
else
{
- tree listvar ;
+ tree listvar;
if (use_p->prev->use == NULL)
- listvar = use_p->prev->stmt;
+ listvar = use_p->prev->loc.ssa_name;
else
listvar = USE_FROM_PTR (use_p->prev);
if (listvar != ssa_name)
fprintf (stderr, "for SSA_NAME: ");
print_generic_expr (stderr, ssa_name, TDF_VOPS);
fprintf (stderr, " in statement:\n");
- print_generic_stmt (stderr, stmt, TDF_VOPS);
+ print_gimple_stmt (stderr, stmt, 0, TDF_VOPS);
}
return err;
/* Return true if any of the arguments for PHI node PHI at block BB is
malformed.
- DEFINITION_BLOCK is an array of basic blocks indexed by SSA_NAME version
- numbers. If DEFINITION_BLOCK[SSA_NAME_VERSION] is set, it means that the
- block in that array slot contains the definition of SSA_NAME. */
+ DEFINITION_BLOCK is an array of basic blocks indexed by SSA_NAME
+ version numbers. If DEFINITION_BLOCK[SSA_NAME_VERSION] is set,
+ it means that the block in that array slot contains the
+ definition of SSA_NAME. */
static bool
-verify_phi_args (tree phi, basic_block bb, basic_block *definition_block)
+verify_phi_args (gimple phi, basic_block bb, basic_block *definition_block)
{
edge e;
bool err = false;
- unsigned i, phi_num_args = PHI_NUM_ARGS (phi);
+ size_t i, phi_num_args = gimple_phi_num_args (phi);
if (EDGE_COUNT (bb->preds) != phi_num_args)
{
for (i = 0; i < phi_num_args; i++)
{
- use_operand_p op_p = PHI_ARG_DEF_PTR (phi, i);
+ use_operand_p op_p = gimple_phi_arg_imm_use_ptr (phi, i);
tree op = USE_FROM_PTR (op_p);
-
e = EDGE_PRED (bb, i);
if (op == NULL_TREE)
}
if (TREE_CODE (op) == SSA_NAME)
- err = verify_use (e->src, definition_block[SSA_NAME_VERSION (op)], op_p,
- phi, e->flags & EDGE_ABNORMAL,
- !is_gimple_reg (PHI_RESULT (phi)),
- NULL);
+ {
+ err = verify_ssa_name (op, !is_gimple_reg (gimple_phi_result (phi)));
+ err |= verify_use (e->src, definition_block[SSA_NAME_VERSION (op)],
+ op_p, phi, e->flags & EDGE_ABNORMAL, NULL);
+ }
+
+ if (TREE_CODE (op) == ADDR_EXPR)
+ {
+ tree base = TREE_OPERAND (op, 0);
+ while (handled_component_p (base))
+ base = TREE_OPERAND (base, 0);
+ if ((TREE_CODE (base) == VAR_DECL
+ || TREE_CODE (base) == PARM_DECL
+ || TREE_CODE (base) == RESULT_DECL)
+ && !TREE_ADDRESSABLE (base))
+ {
+ error ("address taken, but ADDRESSABLE bit not set");
+ err = true;
+ }
+ }
if (e->dest != bb)
{
if (err)
{
fprintf (stderr, "for PHI node\n");
- print_generic_stmt (stderr, phi, TDF_VOPS);
+ print_gimple_stmt (stderr, phi, 0, TDF_VOPS|TDF_MEMSYMS);
}
}
-static void
-verify_flow_insensitive_alias_info (void)
+/* Verify common invariants in the SSA web.
+ TODO: verify the variable annotations. */
+
+DEBUG_FUNCTION void
+verify_ssa (bool check_modified_stmt)
{
- tree var;
- bitmap visited = BITMAP_ALLOC (NULL);
- referenced_var_iterator rvi;
+ size_t i;
+ basic_block bb;
+ basic_block *definition_block = XCNEWVEC (basic_block, num_ssa_names);
+ ssa_op_iter iter;
+ tree op;
+ enum dom_state orig_dom_state = dom_info_state (CDI_DOMINATORS);
+ bitmap names_defined_in_bb = BITMAP_ALLOC (NULL);
- FOR_EACH_REFERENCED_VAR (var, rvi)
- {
- size_t j;
- var_ann_t ann;
- VEC(tree,gc) *may_aliases;
- tree alias;
+ gcc_assert (!need_ssa_update_p (cfun));
- ann = var_ann (var);
- may_aliases = ann->may_aliases;
+ timevar_push (TV_TREE_SSA_VERIFY);
- for (j = 0; VEC_iterate (tree, may_aliases, j, alias); j++)
+ /* Keep track of SSA names present in the IL. */
+ for (i = 1; i < num_ssa_names; i++)
+ {
+ tree name = ssa_name (i);
+ if (name)
{
- bitmap_set_bit (visited, DECL_UID (alias));
+ gimple stmt;
+ TREE_VISITED (name) = 0;
+
+ verify_ssa_name (name, !is_gimple_reg (name));
- if (!may_be_aliased (alias))
+ stmt = SSA_NAME_DEF_STMT (name);
+ if (!gimple_nop_p (stmt))
{
- error ("non-addressable variable inside an alias set");
- debug_variable (alias);
- goto err;
+ basic_block bb = gimple_bb (stmt);
+ verify_def (bb, definition_block,
+ name, stmt, !is_gimple_reg (name));
+
}
}
}
- FOR_EACH_REFERENCED_VAR (var, rvi)
+ calculate_dominance_info (CDI_DOMINATORS);
+
+ /* Now verify all the uses and make sure they agree with the definitions
+ found in the previous pass. */
+ FOR_EACH_BB (bb)
{
- var_ann_t ann;
- ann = var_ann (var);
+ edge e;
+ gimple phi;
+ edge_iterator ei;
+ gimple_stmt_iterator gsi;
- if (!MTAG_P (var)
- && ann->is_aliased
- && !bitmap_bit_p (visited, DECL_UID (var)))
+ /* Make sure that all edges have a clear 'aux' field. */
+ FOR_EACH_EDGE (e, ei, bb->preds)
{
- error ("addressable variable that is aliased but is not in any alias set");
- goto err;
+ if (e->aux)
+ {
+ error ("AUX pointer initialized for edge %d->%d", e->src->index,
+ e->dest->index);
+ goto err;
+ }
}
- }
- BITMAP_FREE (visited);
- return;
+ /* Verify the arguments for every PHI node in the block. */
+ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ phi = gsi_stmt (gsi);
+ if (verify_phi_args (phi, bb, definition_block))
+ goto err;
-err:
- debug_variable (var);
- internal_error ("verify_flow_insensitive_alias_info failed");
-}
+ bitmap_set_bit (names_defined_in_bb,
+ SSA_NAME_VERSION (gimple_phi_result (phi)));
+ }
+ /* Now verify all the uses and vuses in every statement of the block. */
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ use_operand_p use_p;
-static void
-verify_flow_sensitive_alias_info (void)
-{
- size_t i;
- tree ptr;
-
- for (i = 1; i < num_ssa_names; i++)
- {
- tree var;
- var_ann_t ann;
- struct ptr_info_def *pi;
-
-
- ptr = ssa_name (i);
- if (!ptr)
- continue;
-
- /* We only care for pointers that are actually referenced in the
- program. */
- if (!POINTER_TYPE_P (TREE_TYPE (ptr)) || !TREE_VISITED (ptr))
- continue;
-
- /* RESULT_DECL is special. If it's a GIMPLE register, then it
- is only written-to only once in the return statement.
- Otherwise, aggregate RESULT_DECLs may be written-to more than
- once in virtual operands. */
- var = SSA_NAME_VAR (ptr);
- if (TREE_CODE (var) == RESULT_DECL
- && is_gimple_reg (ptr))
- continue;
-
- pi = SSA_NAME_PTR_INFO (ptr);
- if (pi == NULL)
- continue;
-
- ann = var_ann (var);
- if (pi->is_dereferenced && !pi->name_mem_tag && !ann->symbol_mem_tag)
- {
- error ("dereferenced pointers should have a name or a symbol tag");
- goto err;
- }
-
- if (pi->name_mem_tag
- && (pi->pt_vars == NULL || bitmap_empty_p (pi->pt_vars)))
- {
- error ("pointers with a memory tag, should have points-to sets");
- goto err;
- }
-
- if (pi->value_escapes_p
- && pi->name_mem_tag
- && !is_call_clobbered (pi->name_mem_tag))
- {
- error ("pointer escapes but its name tag is not call-clobbered");
- goto err;
- }
- }
-
- return;
-
-err:
- debug_variable (ptr);
- internal_error ("verify_flow_sensitive_alias_info failed");
-}
-
-DEF_VEC_P (bitmap);
-DEF_VEC_ALLOC_P (bitmap,heap);
-
-/* Verify that all name tags have different points to sets.
- This algorithm takes advantage of the fact that every variable with the
- same name tag must have the same points-to set.
- So we check a single variable for each name tag, and verify that its
- points-to set is different from every other points-to set for other name
- tags.
-
- Additionally, given a pointer P_i with name tag NMT and symbol tag
- SMT, this function verified the alias set of SMT is a superset of
- the alias set of NMT. */
-
-static void
-verify_name_tags (void)
-{
- size_t i;
- size_t j;
- bitmap first, second;
- VEC(tree,heap) *name_tag_reps = NULL;
- VEC(bitmap,heap) *pt_vars_for_reps = NULL;
- bitmap type_aliases = BITMAP_ALLOC (NULL);
-
- /* First we compute the name tag representatives and their points-to sets. */
- for (i = 0; i < num_ssa_names; i++)
- {
- struct ptr_info_def *pi;
- tree smt, ptr = ssa_name (i);
-
- if (ptr == NULL_TREE)
- continue;
-
- pi = SSA_NAME_PTR_INFO (ptr);
-
- if (!TREE_VISITED (ptr)
- || !POINTER_TYPE_P (TREE_TYPE (ptr))
- || !pi
- || !pi->name_mem_tag
- || TREE_VISITED (pi->name_mem_tag))
- continue;
-
- TREE_VISITED (pi->name_mem_tag) = 1;
-
- if (pi->pt_vars == NULL)
- continue;
-
- VEC_safe_push (tree, heap, name_tag_reps, ptr);
- VEC_safe_push (bitmap, heap, pt_vars_for_reps, pi->pt_vars);
-
- /* Verify that alias set of PTR's symbol tag is a superset of the
- alias set of PTR's name tag. */
- smt = var_ann (SSA_NAME_VAR (ptr))->symbol_mem_tag;
- if (smt)
- {
- size_t i;
- VEC(tree,gc) *aliases = var_ann (smt)->may_aliases;
- tree alias;
-
- bitmap_clear (type_aliases);
- for (i = 0; VEC_iterate (tree, aliases, i, alias); i++)
- bitmap_set_bit (type_aliases, DECL_UID (alias));
-
- /* When grouping, we may have added PTR's symbol tag into the
- alias set of PTR's name tag. To prevent a false
- positive, pretend that SMT is in its own alias set. */
- bitmap_set_bit (type_aliases, DECL_UID (smt));
-
- if (bitmap_equal_p (type_aliases, pi->pt_vars))
- continue;
-
- if (!bitmap_intersect_compl_p (type_aliases, pi->pt_vars))
+ if (check_modified_stmt && gimple_modified_p (stmt))
{
- error ("alias set of a pointer's symbol tag should be a superset of the corresponding name tag");
- debug_variable (smt);
- debug_variable (pi->name_mem_tag);
+ error ("stmt (%p) marked modified after optimization pass: ",
+ (void *)stmt);
+ print_gimple_stmt (stderr, stmt, 0, TDF_VOPS);
goto err;
}
- }
- }
-
- /* Now compare all the representative bitmaps with all other representative
- bitmaps, to verify that they are all different. */
- for (i = 0; VEC_iterate (bitmap, pt_vars_for_reps, i, first); i++)
- {
- for (j = i + 1; VEC_iterate (bitmap, pt_vars_for_reps, j, second); j++)
- {
- if (bitmap_equal_p (first, second))
- {
- error ("two different pointers with identical points-to sets but different name tags");
- debug_variable (VEC_index (tree, name_tag_reps, j));
- goto err;
- }
- }
- }
-
- /* Lastly, clear out the visited flags. */
- for (i = 0; i < num_ssa_names; i++)
- {
- if (ssa_name (i))
- {
- tree ptr = ssa_name (i);
- struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr);
- if (!TREE_VISITED (ptr)
- || !POINTER_TYPE_P (TREE_TYPE (ptr))
- || !pi
- || !pi->name_mem_tag)
- continue;
- TREE_VISITED (pi->name_mem_tag) = 0;
- }
- }
-
- /* We do not have to free the bitmaps or trees in the vectors, as
- they are not owned by us. */
- VEC_free (bitmap, heap, pt_vars_for_reps);
- VEC_free (tree, heap, name_tag_reps);
- BITMAP_FREE (type_aliases);
- return;
-
-err:
- debug_variable (VEC_index (tree, name_tag_reps, i));
- internal_error ("verify_name_tags failed");
-}
-
-/* Verify the consistency of aliasing information. */
-
-static void
-verify_alias_info (void)
-{
- verify_flow_sensitive_alias_info ();
- verify_name_tags ();
- verify_flow_insensitive_alias_info ();
-}
-
-
-/* Verify common invariants in the SSA web.
- TODO: verify the variable annotations. */
-
-void
-verify_ssa (bool check_modified_stmt)
-{
- size_t i;
- basic_block bb;
- basic_block *definition_block = XCNEWVEC (basic_block, num_ssa_names);
- ssa_op_iter iter;
- tree op;
- enum dom_state orig_dom_state = dom_computed[CDI_DOMINATORS];
- bitmap names_defined_in_bb = BITMAP_ALLOC (NULL);
-
- gcc_assert (!need_ssa_update_p ());
-
- verify_stmts ();
-
- timevar_push (TV_TREE_SSA_VERIFY);
-
- /* Keep track of SSA names present in the IL. */
- for (i = 1; i < num_ssa_names; i++)
- {
- tree name = ssa_name (i);
- if (name)
- {
- tree stmt;
- TREE_VISITED (name) = 0;
-
- stmt = SSA_NAME_DEF_STMT (name);
- if (!IS_EMPTY_STMT (stmt))
+ if (verify_ssa_operands (stmt))
{
- basic_block bb = bb_for_stmt (stmt);
- verify_def (bb, definition_block,
- name, stmt, !is_gimple_reg (name));
-
- }
- }
- }
-
- calculate_dominance_info (CDI_DOMINATORS);
-
- /* Now verify all the uses and make sure they agree with the definitions
- found in the previous pass. */
- FOR_EACH_BB (bb)
- {
- edge e;
- tree phi;
- edge_iterator ei;
- block_stmt_iterator bsi;
-
- /* Make sure that all edges have a clear 'aux' field. */
- FOR_EACH_EDGE (e, ei, bb->preds)
- {
- if (e->aux)
- {
- error ("AUX pointer initialized for edge %d->%d", e->src->index,
- e->dest->index);
+ print_gimple_stmt (stderr, stmt, 0, TDF_VOPS);
goto err;
}
- }
- /* Verify the arguments for every PHI node in the block. */
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
- {
- if (verify_phi_args (phi, bb, definition_block))
- goto err;
- bitmap_set_bit (names_defined_in_bb,
- SSA_NAME_VERSION (PHI_RESULT (phi)));
- }
-
- /* Now verify all the uses and vuses in every statement of the block. */
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- {
- tree stmt = bsi_stmt (bsi);
- use_operand_p use_p;
+ if (gimple_debug_bind_p (stmt)
+ && !gimple_debug_bind_has_value_p (stmt))
+ continue;
- if (check_modified_stmt && stmt_modified_p (stmt))
+ FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE|SSA_OP_VUSE)
{
- error ("stmt (%p) marked modified after optimization pass : ",
- (void *)stmt);
- print_generic_stmt (stderr, stmt, TDF_VOPS);
- goto err;
+ op = USE_FROM_PTR (use_p);
+ if (verify_use (bb, definition_block[SSA_NAME_VERSION (op)],
+ use_p, stmt, false, names_defined_in_bb))
+ goto err;
}
- if (TREE_CODE (stmt) == MODIFY_EXPR
- && TREE_CODE (TREE_OPERAND (stmt, 0)) != SSA_NAME)
+ FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_ALL_DEFS)
{
- tree lhs, base_address;
-
- lhs = TREE_OPERAND (stmt, 0);
- base_address = get_base_address (lhs);
-
- if (base_address
- && SSA_VAR_P (base_address)
- && ZERO_SSA_OPERANDS (stmt, SSA_OP_VMAYDEF|SSA_OP_VMUSTDEF))
+ if (SSA_NAME_DEF_STMT (op) != stmt)
{
- error ("statement makes a memory store, but has no "
- "V_MAY_DEFS nor V_MUST_DEFS");
- print_generic_stmt (stderr, stmt, TDF_VOPS);
+ error ("SSA_NAME_DEF_STMT is wrong");
+ fprintf (stderr, "Expected definition statement:\n");
+ print_gimple_stmt (stderr, stmt, 4, TDF_VOPS);
+ fprintf (stderr, "\nActual definition statement:\n");
+ print_gimple_stmt (stderr, SSA_NAME_DEF_STMT (op),
+ 4, TDF_VOPS);
goto err;
}
+ bitmap_set_bit (names_defined_in_bb, SSA_NAME_VERSION (op));
}
-
- FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter,
- SSA_OP_ALL_USES | SSA_OP_ALL_KILLS)
- {
- op = USE_FROM_PTR (use_p);
- if (verify_use (bb, definition_block[SSA_NAME_VERSION (op)],
- use_p, stmt, false, !is_gimple_reg (op),
- names_defined_in_bb))
- goto err;
- }
-
- FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_ALL_DEFS)
- bitmap_set_bit (names_defined_in_bb, SSA_NAME_VERSION (op));
}
bitmap_clear (names_defined_in_bb);
}
- /* Finally, verify alias information. */
- verify_alias_info ();
-
free (definition_block);
/* Restore the dominance information to its prior known state, so
if (orig_dom_state == DOM_NONE)
free_dominance_info (CDI_DOMINATORS);
else
- dom_computed[CDI_DOMINATORS] = orig_dom_state;
-
+ set_dom_info_availability (CDI_DOMINATORS, orig_dom_state);
+
BITMAP_FREE (names_defined_in_bb);
timevar_pop (TV_TREE_SSA_VERIFY);
return;
return ((const struct int_tree_map *)item)->uid;
}
+/* Return true if the DECL_UID in both trees are equal. */
+
+int
+uid_decl_map_eq (const void *va, const void *vb)
+{
+ const_tree a = (const_tree) va;
+ const_tree b = (const_tree) vb;
+ return (a->decl_minimal.uid == b->decl_minimal.uid);
+}
+
+/* Hash a tree in a uid_decl_map. */
+
+unsigned int
+uid_decl_map_hash (const void *item)
+{
+ return ((const_tree)item)->decl_minimal.uid;
+}
+
+/* Return true if the DECL_UID in both trees are equal. */
+
+static int
+uid_ssaname_map_eq (const void *va, const void *vb)
+{
+ const_tree a = (const_tree) va;
+ const_tree b = (const_tree) vb;
+ return (a->ssa_name.var->decl_minimal.uid == b->ssa_name.var->decl_minimal.uid);
+}
+
+/* Hash a tree in a uid_decl_map. */
+
+static unsigned int
+uid_ssaname_map_hash (const void *item)
+{
+ return ((const_tree)item)->ssa_name.var->decl_minimal.uid;
+}
+
/* Initialize global DFA and SSA structures. */
void
-init_tree_ssa (void)
+init_tree_ssa (struct function *fn)
{
- referenced_vars = htab_create_ggc (20, int_tree_map_hash,
- int_tree_map_eq, NULL);
- default_defs = htab_create_ggc (20, int_tree_map_hash, int_tree_map_eq, NULL);
- call_clobbered_vars = BITMAP_ALLOC (NULL);
- addressable_vars = BITMAP_ALLOC (NULL);
- init_alias_heapvars ();
- init_ssanames ();
+ fn->gimple_df = ggc_alloc_cleared_gimple_df ();
+ 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,
+ uid_ssaname_map_eq, NULL);
+ pt_solution_reset (&fn->gimple_df->escaped);
+ init_ssanames (fn, 0);
init_phinodes ();
- global_var = NULL_TREE;
- aliases_computed_p = false;
}
void
delete_tree_ssa (void)
{
- size_t i;
- basic_block bb;
- block_stmt_iterator bsi;
referenced_var_iterator rvi;
tree var;
- /* Release any ssa_names still in use. */
- for (i = 0; i < num_ssa_names; i++)
- {
- tree var = ssa_name (i);
- if (var && TREE_CODE (var) == SSA_NAME)
- {
- SSA_NAME_IMM_USE_NODE (var).prev = &(SSA_NAME_IMM_USE_NODE (var));
- SSA_NAME_IMM_USE_NODE (var).next = &(SSA_NAME_IMM_USE_NODE (var));
- }
- release_ssa_name (var);
- }
-
- /* Remove annotations from every tree in the function. */
- FOR_EACH_BB (bb)
+ /* Remove annotations from every referenced local variable. */
+ FOR_EACH_REFERENCED_VAR (cfun, var, rvi)
{
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
+ if (is_global_var (var))
+ continue;
+ if (var_ann (var))
{
- tree stmt = bsi_stmt (bsi);
- stmt_ann_t ann = get_stmt_ann (stmt);
-
- free_ssa_operands (&ann->operands);
- ann->addresses_taken = 0;
- mark_stmt_modified (stmt);
+ ggc_free (var_ann (var));
+ *DECL_VAR_ANN_PTR (var) = NULL;
}
- set_phi_nodes (bb, NULL);
- }
-
- /* Remove annotations from every referenced variable. */
- FOR_EACH_REFERENCED_VAR (var, rvi)
- {
- ggc_free (var->common.ann);
- var->common.ann = NULL;
}
- htab_delete (referenced_vars);
- referenced_vars = NULL;
+ htab_delete (gimple_referenced_vars (cfun));
+ cfun->gimple_df->referenced_vars = NULL;
fini_ssanames ();
fini_phinodes ();
- global_var = NULL_TREE;
-
- htab_delete (default_defs);
- BITMAP_FREE (call_clobbered_vars);
- call_clobbered_vars = NULL;
- BITMAP_FREE (addressable_vars);
- addressable_vars = NULL;
- modified_noreturn_calls = NULL;
- aliases_computed_p = false;
- delete_alias_heapvars ();
- gcc_assert (!need_ssa_update_p ());
+ /* We no longer maintain the SSA operand cache at this point. */
+ if (ssa_operands_active ())
+ fini_ssa_operands ();
+
+ htab_delete (cfun->gimple_df->default_defs);
+ cfun->gimple_df->default_defs = NULL;
+ pt_solution_reset (&cfun->gimple_df->escaped);
+ if (cfun->gimple_df->decls_to_pointers != NULL)
+ pointer_map_destroy (cfun->gimple_df->decls_to_pointers);
+ cfun->gimple_df->decls_to_pointers = NULL;
+ cfun->gimple_df->modified_noreturn_calls = NULL;
+ cfun->gimple_df = NULL;
+
+ /* We no longer need the edge variable maps. */
+ redirect_edge_var_map_destroy ();
}
-
/* Return true if the conversion from INNER_TYPE to OUTER_TYPE is a
- useless type conversion, otherwise return false. */
+ useless type conversion, otherwise return false.
+
+ This function implicitly defines the middle-end type system. With
+ the notion of 'a < b' meaning that useless_type_conversion_p (a, b)
+ holds and 'a > b' meaning that useless_type_conversion_p (b, a) holds,
+ the following invariants shall be fulfilled:
+
+ 1) useless_type_conversion_p is transitive.
+ If a < b and b < c then a < c.
+
+ 2) useless_type_conversion_p is not symmetric.
+ From a < b does not follow a > b.
+
+ 3) Types define the available set of operations applicable to values.
+ A type conversion is useless if the operations for the target type
+ is a subset of the operations for the source type. For example
+ casts to void* are useless, casts from void* are not (void* can't
+ be dereferenced or offsetted, but copied, hence its set of operations
+ is a strict subset of that of all other data pointer types). Casts
+ to const T* are useless (can't be written to), casts from const T*
+ to T* are not. */
bool
-tree_ssa_useless_type_conversion_1 (tree outer_type, tree inner_type)
+useless_type_conversion_p (tree outer_type, tree inner_type)
{
+ /* Do the following before stripping toplevel qualifiers. */
+ if (POINTER_TYPE_P (inner_type)
+ && POINTER_TYPE_P (outer_type))
+ {
+ /* Do not lose casts between pointers to different address spaces. */
+ if (TYPE_ADDR_SPACE (TREE_TYPE (outer_type))
+ != TYPE_ADDR_SPACE (TREE_TYPE (inner_type)))
+ return false;
+ }
+
+ /* From now on qualifiers on value types do not matter. */
+ inner_type = TYPE_MAIN_VARIANT (inner_type);
+ outer_type = TYPE_MAIN_VARIANT (outer_type);
+
if (inner_type == outer_type)
return true;
- /* Changes in machine mode are never useless conversions. */
- if (TYPE_MODE (inner_type) != TYPE_MODE (outer_type))
+ /* If we know the canonical types, compare them. */
+ if (TYPE_CANONICAL (inner_type)
+ && TYPE_CANONICAL (inner_type) == TYPE_CANONICAL (outer_type))
+ return true;
+
+ /* Changes in machine mode are never useless conversions unless we
+ deal with aggregate types in which case we defer to later checks. */
+ if (TYPE_MODE (inner_type) != TYPE_MODE (outer_type)
+ && !AGGREGATE_TYPE_P (inner_type))
return false;
- /* If the inner and outer types are effectively the same, then
- strip the type conversion and enter the equivalence into
- the table. */
- if (lang_hooks.types_compatible_p (inner_type, outer_type))
+ /* If both the inner and outer types are integral types, then the
+ conversion is not necessary if they have the same mode and
+ signedness and precision, and both or neither are boolean. */
+ if (INTEGRAL_TYPE_P (inner_type)
+ && INTEGRAL_TYPE_P (outer_type))
+ {
+ /* Preserve changes in signedness or precision. */
+ if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
+ || TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
+ return false;
+
+ /* Preserve conversions to/from BOOLEAN_TYPE if types are not
+ of precision one. */
+ if (((TREE_CODE (inner_type) == BOOLEAN_TYPE)
+ != (TREE_CODE (outer_type) == BOOLEAN_TYPE))
+ && TYPE_PRECISION (outer_type) != 1)
+ return false;
+
+ /* We don't need to preserve changes in the types minimum or
+ maximum value in general as these do not generate code
+ unless the types precisions are different. */
+ return true;
+ }
+
+ /* Scalar floating point types with the same mode are compatible. */
+ else if (SCALAR_FLOAT_TYPE_P (inner_type)
+ && SCALAR_FLOAT_TYPE_P (outer_type))
return true;
- /* If both types are pointers and the outer type is a (void *), then
- the conversion is not necessary. The opposite is not true since
- that conversion would result in a loss of information if the
- equivalence was used. Consider an indirect function call where
- we need to know the exact type of the function to correctly
- implement the ABI. */
- else if (POINTER_TYPE_P (inner_type)
- && POINTER_TYPE_P (outer_type)
- && TYPE_REF_CAN_ALIAS_ALL (inner_type)
- == TYPE_REF_CAN_ALIAS_ALL (outer_type)
- && TREE_CODE (TREE_TYPE (outer_type)) == VOID_TYPE)
+ /* Fixed point types with the same mode are compatible. */
+ else if (FIXED_POINT_TYPE_P (inner_type)
+ && FIXED_POINT_TYPE_P (outer_type))
return true;
- /* Don't lose casts between pointers to volatile and non-volatile
- qualified types. Doing so would result in changing the semantics
- of later accesses. */
+ /* We need to take special care recursing to pointed-to types. */
else if (POINTER_TYPE_P (inner_type)
- && POINTER_TYPE_P (outer_type)
- && TYPE_VOLATILE (TREE_TYPE (outer_type))
- != TYPE_VOLATILE (TREE_TYPE (inner_type)))
- return false;
+ && POINTER_TYPE_P (outer_type))
+ {
+ /* Do not lose casts to function pointer types. */
+ if ((TREE_CODE (TREE_TYPE (outer_type)) == FUNCTION_TYPE
+ || TREE_CODE (TREE_TYPE (outer_type)) == METHOD_TYPE)
+ && !(TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE
+ || TREE_CODE (TREE_TYPE (inner_type)) == METHOD_TYPE))
+ return false;
- /* Pointers/references are equivalent if their pointed to types
- are effectively the same. This allows to strip conversions between
- pointer types with different type qualifiers. */
- else if (POINTER_TYPE_P (inner_type)
- && POINTER_TYPE_P (outer_type)
- && TYPE_REF_CAN_ALIAS_ALL (inner_type)
- == TYPE_REF_CAN_ALIAS_ALL (outer_type)
- && lang_hooks.types_compatible_p (TREE_TYPE (inner_type),
- TREE_TYPE (outer_type)))
- return true;
+ /* We do not care for const qualification of the pointed-to types
+ as const qualification has no semantic value to the middle-end. */
- /* If both the inner and outer types are integral types, then the
- conversion is not necessary if they have the same mode and
- signedness and precision, and both or neither are boolean. Some
- code assumes an invariant that boolean types stay boolean and do
- not become 1-bit bit-field types. Note that types with precision
- not using all bits of the mode (such as bit-field types in C)
- mean that testing of precision is necessary. */
- else if (INTEGRAL_TYPE_P (inner_type)
- && INTEGRAL_TYPE_P (outer_type)
- && TYPE_UNSIGNED (inner_type) == TYPE_UNSIGNED (outer_type)
- && TYPE_PRECISION (inner_type) == TYPE_PRECISION (outer_type)
- && simple_cst_equal (TYPE_MAX_VALUE (inner_type), TYPE_MAX_VALUE (outer_type))
- && simple_cst_equal (TYPE_MIN_VALUE (inner_type), TYPE_MIN_VALUE (outer_type)))
- {
- bool first_boolean = (TREE_CODE (inner_type) == BOOLEAN_TYPE);
- bool second_boolean = (TREE_CODE (outer_type) == BOOLEAN_TYPE);
- if (first_boolean == second_boolean)
- return true;
+ /* Otherwise pointers/references are equivalent. */
+ return true;
}
/* Recurse for complex types. */
else if (TREE_CODE (inner_type) == COMPLEX_TYPE
- && TREE_CODE (outer_type) == COMPLEX_TYPE
- && tree_ssa_useless_type_conversion_1 (TREE_TYPE (outer_type),
- TREE_TYPE (inner_type)))
- return true;
+ && TREE_CODE (outer_type) == COMPLEX_TYPE)
+ return useless_type_conversion_p (TREE_TYPE (outer_type),
+ TREE_TYPE (inner_type));
+
+ /* Recurse for vector types with the same number of subparts. */
+ else if (TREE_CODE (inner_type) == VECTOR_TYPE
+ && TREE_CODE (outer_type) == VECTOR_TYPE
+ && TYPE_PRECISION (inner_type) == TYPE_PRECISION (outer_type))
+ return useless_type_conversion_p (TREE_TYPE (outer_type),
+ TREE_TYPE (inner_type));
+
+ else if (TREE_CODE (inner_type) == ARRAY_TYPE
+ && TREE_CODE (outer_type) == ARRAY_TYPE)
+ {
+ /* Preserve string attributes. */
+ if (TYPE_STRING_FLAG (inner_type) != TYPE_STRING_FLAG (outer_type))
+ return false;
+
+ /* Conversions from array types with unknown extent to
+ array types with known extent are not useless. */
+ if (!TYPE_DOMAIN (inner_type)
+ && TYPE_DOMAIN (outer_type))
+ return false;
+
+ /* Nor are conversions from array types with non-constant size to
+ array types with constant size or to different size. */
+ if (TYPE_SIZE (outer_type)
+ && TREE_CODE (TYPE_SIZE (outer_type)) == INTEGER_CST
+ && (!TYPE_SIZE (inner_type)
+ || TREE_CODE (TYPE_SIZE (inner_type)) != INTEGER_CST
+ || !tree_int_cst_equal (TYPE_SIZE (outer_type),
+ TYPE_SIZE (inner_type))))
+ return false;
+
+ /* Check conversions between arrays with partially known extents.
+ If the array min/max values are constant they have to match.
+ Otherwise allow conversions to unknown and variable extents.
+ In particular this declares conversions that may change the
+ mode to BLKmode as useless. */
+ if (TYPE_DOMAIN (inner_type)
+ && TYPE_DOMAIN (outer_type)
+ && TYPE_DOMAIN (inner_type) != TYPE_DOMAIN (outer_type))
+ {
+ tree inner_min = TYPE_MIN_VALUE (TYPE_DOMAIN (inner_type));
+ tree outer_min = TYPE_MIN_VALUE (TYPE_DOMAIN (outer_type));
+ tree inner_max = TYPE_MAX_VALUE (TYPE_DOMAIN (inner_type));
+ tree outer_max = TYPE_MAX_VALUE (TYPE_DOMAIN (outer_type));
+
+ /* After gimplification a variable min/max value carries no
+ additional information compared to a NULL value. All that
+ matters has been lowered to be part of the IL. */
+ if (inner_min && TREE_CODE (inner_min) != INTEGER_CST)
+ inner_min = NULL_TREE;
+ if (outer_min && TREE_CODE (outer_min) != INTEGER_CST)
+ outer_min = NULL_TREE;
+ if (inner_max && TREE_CODE (inner_max) != INTEGER_CST)
+ inner_max = NULL_TREE;
+ if (outer_max && TREE_CODE (outer_max) != INTEGER_CST)
+ outer_max = NULL_TREE;
+
+ /* Conversions NULL / variable <- cst are useless, but not
+ the other way around. */
+ if (outer_min
+ && (!inner_min
+ || !tree_int_cst_equal (inner_min, outer_min)))
+ return false;
+ if (outer_max
+ && (!inner_max
+ || !tree_int_cst_equal (inner_max, outer_max)))
+ return false;
+ }
+
+ /* Recurse on the element check. */
+ return useless_type_conversion_p (TREE_TYPE (outer_type),
+ TREE_TYPE (inner_type));
+ }
+
+ else if ((TREE_CODE (inner_type) == FUNCTION_TYPE
+ || TREE_CODE (inner_type) == METHOD_TYPE)
+ && TREE_CODE (inner_type) == TREE_CODE (outer_type))
+ {
+ tree outer_parm, inner_parm;
+
+ /* If the return types are not compatible bail out. */
+ if (!useless_type_conversion_p (TREE_TYPE (outer_type),
+ TREE_TYPE (inner_type)))
+ return false;
+
+ /* Method types should belong to a compatible base class. */
+ if (TREE_CODE (inner_type) == METHOD_TYPE
+ && !useless_type_conversion_p (TYPE_METHOD_BASETYPE (outer_type),
+ TYPE_METHOD_BASETYPE (inner_type)))
+ return false;
+
+ /* A conversion to an unprototyped argument list is ok. */
+ if (!prototype_p (outer_type))
+ return true;
+
+ /* If the unqualified argument types are compatible the conversion
+ is useless. */
+ if (TYPE_ARG_TYPES (outer_type) == TYPE_ARG_TYPES (inner_type))
+ return true;
+
+ for (outer_parm = TYPE_ARG_TYPES (outer_type),
+ inner_parm = TYPE_ARG_TYPES (inner_type);
+ outer_parm && inner_parm;
+ outer_parm = TREE_CHAIN (outer_parm),
+ inner_parm = TREE_CHAIN (inner_parm))
+ if (!useless_type_conversion_p
+ (TYPE_MAIN_VARIANT (TREE_VALUE (outer_parm)),
+ TYPE_MAIN_VARIANT (TREE_VALUE (inner_parm))))
+ return false;
+
+ /* If there is a mismatch in the number of arguments the functions
+ are not compatible. */
+ if (outer_parm || inner_parm)
+ return false;
+
+ /* Defer to the target if necessary. */
+ if (TYPE_ATTRIBUTES (inner_type) || TYPE_ATTRIBUTES (outer_type))
+ return comp_type_attributes (outer_type, inner_type) != 0;
+
+ return true;
+ }
+
+ /* For aggregates we rely on TYPE_CANONICAL exclusively and require
+ explicit conversions for types involving to be structurally
+ compared types. */
+ else if (AGGREGATE_TYPE_P (inner_type)
+ && TREE_CODE (inner_type) == TREE_CODE (outer_type))
+ return false;
return false;
}
+/* Return true if a conversion from either type of TYPE1 and TYPE2
+ to the other is not required. Otherwise return false. */
+
+bool
+types_compatible_p (tree type1, tree type2)
+{
+ return (type1 == type2
+ || (useless_type_conversion_p (type1, type2)
+ && useless_type_conversion_p (type2, type1)));
+}
+
/* Return true if EXPR is a useless type conversion, otherwise return
false. */
the top of the RHS to the type of the LHS and the type conversion
is "safe", then strip away the type conversion so that we can
enter LHS = RHS into the const_and_copies table. */
- if (TREE_CODE (expr) == NOP_EXPR || TREE_CODE (expr) == CONVERT_EXPR
+ if (CONVERT_EXPR_P (expr)
|| TREE_CODE (expr) == VIEW_CONVERT_EXPR
|| TREE_CODE (expr) == NON_LVALUE_EXPR)
- return tree_ssa_useless_type_conversion_1 (TREE_TYPE (expr),
- TREE_TYPE (TREE_OPERAND (expr,
- 0)));
-
+ return useless_type_conversion_p
+ (TREE_TYPE (expr),
+ TREE_TYPE (TREE_OPERAND (expr, 0)));
return false;
}
-/* Returns true if statement STMT may read memory. */
+/* Strip conversions from EXP according to
+ tree_ssa_useless_type_conversion and return the resulting
+ expression. */
-bool
-stmt_references_memory_p (tree stmt)
+tree
+tree_ssa_strip_useless_type_conversions (tree exp)
{
- stmt_ann_t ann = stmt_ann (stmt);
-
- if (ann->has_volatile_ops)
- return true;
-
- return (!ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS));
+ while (tree_ssa_useless_type_conversion (exp))
+ exp = TREE_OPERAND (exp, 0);
+ return exp;
}
+
/* 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
walk_use_def_chains_1 (tree var, walk_use_def_chains_fn fn, void *data,
struct pointer_set_t *visited, bool is_dfs)
{
- tree def_stmt;
+ gimple def_stmt;
if (pointer_set_insert (visited, var))
return false;
def_stmt = SSA_NAME_DEF_STMT (var);
- if (TREE_CODE (def_stmt) != PHI_NODE)
+ if (gimple_code (def_stmt) != GIMPLE_PHI)
{
/* If we reached the end of the use-def chain, call FN. */
return fn (var, def_stmt, data);
}
else
{
- int i;
+ size_t i;
/* When doing a breadth-first search, call FN before following the
use-def links for each argument. */
if (!is_dfs)
- for (i = 0; i < PHI_NUM_ARGS (def_stmt); i++)
- if (fn (PHI_ARG_DEF (def_stmt, i), def_stmt, data))
+ for (i = 0; i < gimple_phi_num_args (def_stmt); i++)
+ if (fn (gimple_phi_arg_def (def_stmt, i), def_stmt, data))
return true;
/* Follow use-def links out of each PHI argument. */
- for (i = 0; i < PHI_NUM_ARGS (def_stmt); i++)
+ for (i = 0; i < gimple_phi_num_args (def_stmt); i++)
{
- tree arg = PHI_ARG_DEF (def_stmt, i);
- if (TREE_CODE (arg) == SSA_NAME
+ tree arg = gimple_phi_arg_def (def_stmt, i);
+
+ /* ARG may be NULL for newly introduced PHI nodes. */
+ if (arg
+ && TREE_CODE (arg) == SSA_NAME
&& walk_use_def_chains_1 (arg, fn, data, visited, is_dfs))
return true;
}
/* When doing a depth-first search, call FN after following the
use-def links for each argument. */
if (is_dfs)
- for (i = 0; i < PHI_NUM_ARGS (def_stmt); i++)
- if (fn (PHI_ARG_DEF (def_stmt, i), def_stmt, data))
+ for (i = 0; i < gimple_phi_num_args (def_stmt); i++)
+ 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
If IS_DFS is false, the two steps above are done in reverse order
(i.e., a breadth-first search). */
-
void
walk_use_def_chains (tree var, walk_use_def_chains_fn fn, void *data,
bool is_dfs)
{
- tree def_stmt;
+ gimple def_stmt;
gcc_assert (TREE_CODE (var) == SSA_NAME);
/* We only need to recurse if the reaching definition comes from a PHI
node. */
- if (TREE_CODE (def_stmt) != PHI_NODE)
+ if (gimple_code (def_stmt) != GIMPLE_PHI)
(*fn) (var, def_stmt, data);
else
{
\f
/* Emit warnings for uninitialized variables. This is done in two passes.
- The first pass notices real uses of SSA names with default definitions.
+ The first pass notices real uses of SSA names with undefined values.
Such uses are unconditionally uninitialized, and we can be certain that
such a use is a mistake. This pass is run before most optimizations,
so that we catch as many as we can.
again for plain uninitialized variables, since optimization may have
changed conditionally uninitialized to unconditionally uninitialized. */
-/* 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. */
+/* Emit a warning for EXPR based on variable VAR at the point in the
+ program T, an SSA_NAME, is used being uninitialized. The exact
+ warning text is in MSGID and LOCUS may contain a location or be null.
+ WC is the warning code. */
-static void
-warn_uninit (tree t, const char *gmsgid, void *data)
+void
+warn_uninit (enum opt_code wc, tree t,
+ tree expr, tree var, const char *gmsgid, void *data)
{
- tree var = SSA_NAME_VAR (t);
- tree def = SSA_NAME_DEF_STMT (t);
- tree context = (tree) data;
- location_t * locus;
-
- /* Default uses (indicated by an empty definition statement),
- are uninitialized. */
- if (!IS_EMPTY_STMT (def))
- return;
-
- /* Except for PARMs of course, which are always initialized. */
- if (TREE_CODE (var) == PARM_DECL)
- return;
+ gimple context = (gimple) data;
+ location_t location;
+ expanded_location xloc, floc;
- /* Hard register variables get their initial value from the ether. */
- if (TREE_CODE (var) == VAR_DECL && DECL_HARD_REGISTER (var))
+ if (!ssa_undefined_value_p (t))
return;
/* TREE_NO_WARNING either means we already warned, or the front end
wishes to suppress the warning. */
- if (TREE_NO_WARNING (var))
+ if ((context
+ && (gimple_no_warning_p (context)
+ || (gimple_assign_single_p (context)
+ && TREE_NO_WARNING (gimple_assign_rhs1 (context)))))
+ || TREE_NO_WARNING (expr))
return;
- locus = (context != NULL && EXPR_HAS_LOCATION (context)
- ? EXPR_LOCUS (context)
- : &DECL_SOURCE_LOCATION (var));
- warning (0, gmsgid, locus, var);
- TREE_NO_WARNING (var) = 1;
+ location = (context != NULL && gimple_has_location (context))
+ ? gimple_location (context)
+ : DECL_SOURCE_LOCATION (var);
+ xloc = expand_location (location);
+ floc = expand_location (DECL_SOURCE_LOCATION (cfun->decl));
+ if (warning_at (location, wc, gmsgid, expr))
+ {
+ TREE_NO_WARNING (expr) = 1;
+
+ if (location == DECL_SOURCE_LOCATION (var))
+ return;
+ if (xloc.file != floc.file
+ || xloc.line < floc.line
+ || xloc.line > LOCATION_LINE (cfun->function_end_locus))
+ inform (DECL_SOURCE_LOCATION (var), "%qD was declared here", var);
+ }
}
-
-/* Called via walk_tree, look for SSA_NAMEs that have empty definitions
- and warn about them. */
-static tree
-warn_uninitialized_var (tree *tp, int *walk_subtrees, void *data)
+unsigned int
+warn_uninitialized_vars (bool warn_possibly_uninitialized)
{
- tree t = *tp;
+ gimple_stmt_iterator gsi;
+ basic_block bb;
- switch (TREE_CODE (t))
+ FOR_EACH_BB (bb)
{
- case SSA_NAME:
- /* We only do data flow with SSA_NAMEs, so that's all we
- can warn about. */
- warn_uninit (t, "%H%qD is used uninitialized in this function", data);
- *walk_subtrees = 0;
- break;
-
- case REALPART_EXPR:
- case IMAGPART_EXPR:
- /* The total store transformation performed during gimplification
- creates uninitialized variable uses. If all is well, these will
- be optimized away, so don't warn now. */
- if (TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME)
- *walk_subtrees = 0;
- break;
-
- default:
- if (IS_TYPE_OR_DECL_P (t))
- *walk_subtrees = 0;
- break;
- }
-
- return NULL_TREE;
-}
-
-/* Look for inputs to PHI that are SSA_NAMEs that have empty definitions
- and warn about them. */
+ bool always_executed = dominated_by_p (CDI_POST_DOMINATORS,
+ single_succ (ENTRY_BLOCK_PTR), bb);
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ use_operand_p use_p;
+ ssa_op_iter op_iter;
+ tree use;
-static void
-warn_uninitialized_phi (tree phi)
-{
- int i, n = PHI_NUM_ARGS (phi);
+ if (is_gimple_debug (stmt))
+ continue;
- /* Don't look at memory tags. */
- if (!is_gimple_reg (PHI_RESULT (phi)))
- return;
+ /* We only do data flow with SSA_NAMEs, so that's all we
+ can warn about. */
+ FOR_EACH_SSA_USE_OPERAND (use_p, stmt, op_iter, SSA_OP_USE)
+ {
+ use = USE_FROM_PTR (use_p);
+ if (always_executed)
+ warn_uninit (OPT_Wuninitialized, use,
+ SSA_NAME_VAR (use), SSA_NAME_VAR (use),
+ "%qD is used uninitialized in this function",
+ stmt);
+ else if (warn_possibly_uninitialized)
+ warn_uninit (OPT_Wuninitialized, use,
+ SSA_NAME_VAR (use), SSA_NAME_VAR (use),
+ "%qD may be used uninitialized in this function",
+ stmt);
+ }
- for (i = 0; i < n; ++i)
- {
- tree op = PHI_ARG_DEF (phi, i);
- if (TREE_CODE (op) == SSA_NAME)
- warn_uninit (op, "%H%qD may be used uninitialized in this function",
- NULL);
+ /* For memory the only cheap thing we can do is see if we
+ have a use of the default def of the virtual operand.
+ ??? Note that at -O0 we do not have virtual operands.
+ ??? Not so cheap would be to use the alias oracle via
+ walk_aliased_vdefs, if we don't find any aliasing vdef
+ warn as is-used-uninitialized, if we don't find an aliasing
+ vdef that kills our use (stmt_kills_ref_p), warn as
+ may-be-used-uninitialized. But this walk is quadratic and
+ so must be limited which means we would miss warning
+ opportunities. */
+ use = gimple_vuse (stmt);
+ if (use
+ && gimple_assign_single_p (stmt)
+ && !gimple_vdef (stmt)
+ && SSA_NAME_IS_DEFAULT_DEF (use))
+ {
+ tree rhs = gimple_assign_rhs1 (stmt);
+ tree base = get_base_address (rhs);
+
+ /* Do not warn if it can be initialized outside this function. */
+ if (TREE_CODE (base) != VAR_DECL
+ || DECL_HARD_REGISTER (base)
+ || is_global_var (base))
+ continue;
+
+ if (always_executed)
+ warn_uninit (OPT_Wuninitialized, use, gimple_assign_rhs1 (stmt),
+ base,
+ "%qE is used uninitialized in this function",
+ stmt);
+ else if (warn_possibly_uninitialized)
+ warn_uninit (OPT_Wuninitialized, use, gimple_assign_rhs1 (stmt),
+ base,
+ "%qE may be used uninitialized in this function",
+ stmt);
+ }
+ }
}
+
+ return 0;
}
-static void
+static unsigned int
execute_early_warn_uninitialized (void)
{
- block_stmt_iterator bsi;
- basic_block bb;
-
- FOR_EACH_BB (bb)
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- {
- tree context = bsi_stmt (bsi);
- walk_tree (bsi_stmt_ptr (bsi), warn_uninitialized_var,
- context, NULL);
- }
-}
+ /* Currently, this pass runs always but
+ execute_late_warn_uninitialized only runs with optimization. With
+ optimization we want to warn about possible uninitialized as late
+ as possible, thus don't do it here. However, without
+ optimization we need to warn here about "may be uninitialized".
+ */
+ calculate_dominance_info (CDI_POST_DOMINATORS);
-static void
-execute_late_warn_uninitialized (void)
-{
- basic_block bb;
- tree phi;
+ warn_uninitialized_vars (/*warn_possibly_uninitialized=*/!optimize);
- /* 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. */
- execute_early_warn_uninitialized ();
+ /* Post-dominator information can not be reliably updated. Free it
+ after the use. */
- FOR_EACH_BB (bb)
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
- warn_uninitialized_phi (phi);
+ free_dominance_info (CDI_POST_DOMINATORS);
+ return 0;
}
static bool
return warn_uninitialized != 0;
}
-struct tree_opt_pass pass_early_warn_uninitialized =
+struct gimple_opt_pass pass_early_warn_uninitialized =
{
- NULL, /* name */
+ {
+ GIMPLE_PASS,
+ "*early_warn_uninitialized", /* name */
gate_warn_uninitialized, /* gate */
execute_early_warn_uninitialized, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
- 0, /* tv_id */
+ TV_TREE_UNINIT, /* tv_id */
PROP_ssa, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- 0, /* todo_flags_finish */
- 0 /* letter */
+ 0 /* todo_flags_finish */
+ }
};
-struct tree_opt_pass pass_late_warn_uninitialized =
+
+/* If necessary, rewrite the base of the reference tree *TP from
+ a MEM_REF to a plain or converted symbol. */
+
+static void
+maybe_rewrite_mem_ref_base (tree *tp)
{
- NULL, /* name */
- gate_warn_uninitialized, /* gate */
- execute_late_warn_uninitialized, /* execute */
+ tree sym;
+
+ while (handled_component_p (*tp))
+ tp = &TREE_OPERAND (*tp, 0);
+ if (TREE_CODE (*tp) == MEM_REF
+ && TREE_CODE (TREE_OPERAND (*tp, 0)) == ADDR_EXPR
+ && (sym = TREE_OPERAND (TREE_OPERAND (*tp, 0), 0))
+ && DECL_P (sym)
+ && !TREE_ADDRESSABLE (sym)
+ && symbol_marked_for_renaming (sym))
+ {
+ if (TREE_CODE (TREE_TYPE (sym)) == VECTOR_TYPE
+ && useless_type_conversion_p (TREE_TYPE (*tp),
+ TREE_TYPE (TREE_TYPE (sym)))
+ && multiple_of_p (sizetype, TREE_OPERAND (*tp, 1),
+ TYPE_SIZE_UNIT (TREE_TYPE (*tp))))
+ {
+ *tp = build3 (BIT_FIELD_REF, TREE_TYPE (*tp), sym,
+ TYPE_SIZE (TREE_TYPE (*tp)),
+ int_const_binop (MULT_EXPR,
+ bitsize_int (BITS_PER_UNIT),
+ TREE_OPERAND (*tp, 1)));
+ }
+ else if (TREE_CODE (TREE_TYPE (sym)) == COMPLEX_TYPE
+ && useless_type_conversion_p (TREE_TYPE (*tp),
+ TREE_TYPE (TREE_TYPE (sym))))
+ {
+ *tp = build1 (integer_zerop (TREE_OPERAND (*tp, 1))
+ ? REALPART_EXPR : IMAGPART_EXPR,
+ TREE_TYPE (*tp), sym);
+ }
+ else if (integer_zerop (TREE_OPERAND (*tp, 1)))
+ {
+ if (!useless_type_conversion_p (TREE_TYPE (*tp),
+ TREE_TYPE (sym)))
+ *tp = build1 (VIEW_CONVERT_EXPR,
+ TREE_TYPE (*tp), sym);
+ else
+ *tp = sym;
+ }
+ }
+}
+
+/* For a tree REF return its base if it is the base of a MEM_REF
+ that cannot be rewritten into SSA form. Otherwise return NULL_TREE. */
+
+static tree
+non_rewritable_mem_ref_base (tree ref)
+{
+ tree base = ref;
+
+ /* A plain decl does not need it set. */
+ if (DECL_P (ref))
+ return NULL_TREE;
+
+ while (handled_component_p (base))
+ base = TREE_OPERAND (base, 0);
+
+ /* But watch out for MEM_REFs we cannot lower to a
+ VIEW_CONVERT_EXPR or a BIT_FIELD_REF. */
+ if (TREE_CODE (base) == MEM_REF
+ && TREE_CODE (TREE_OPERAND (base, 0)) == ADDR_EXPR)
+ {
+ tree decl = TREE_OPERAND (TREE_OPERAND (base, 0), 0);
+ if ((TREE_CODE (TREE_TYPE (decl)) == VECTOR_TYPE
+ || TREE_CODE (TREE_TYPE (decl)) == COMPLEX_TYPE)
+ && useless_type_conversion_p (TREE_TYPE (base),
+ TREE_TYPE (TREE_TYPE (decl)))
+ && double_int_fits_in_uhwi_p (mem_ref_offset (base))
+ && double_int_ucmp
+ (tree_to_double_int (TYPE_SIZE_UNIT (TREE_TYPE (decl))),
+ mem_ref_offset (base)) == 1
+ && multiple_of_p (sizetype, TREE_OPERAND (base, 1),
+ TYPE_SIZE_UNIT (TREE_TYPE (base))))
+ return NULL_TREE;
+ if (DECL_P (decl)
+ && (!integer_zerop (TREE_OPERAND (base, 1))
+ || (DECL_SIZE (decl)
+ != TYPE_SIZE (TREE_TYPE (base)))
+ || TREE_THIS_VOLATILE (decl) != TREE_THIS_VOLATILE (base)))
+ return decl;
+ }
+
+ return NULL_TREE;
+}
+
+/* For an lvalue tree LHS return true if it cannot be rewritten into SSA form.
+ Otherwise return true. */
+
+static bool
+non_rewritable_lvalue_p (tree lhs)
+{
+ /* A plain decl is always rewritable. */
+ if (DECL_P (lhs))
+ return false;
+
+ /* A decl that is wrapped inside a MEM-REF that covers
+ it full is also rewritable.
+ ??? The following could be relaxed allowing component
+ references that do not change the access size. */
+ if (TREE_CODE (lhs) == MEM_REF
+ && TREE_CODE (TREE_OPERAND (lhs, 0)) == ADDR_EXPR
+ && integer_zerop (TREE_OPERAND (lhs, 1)))
+ {
+ tree decl = TREE_OPERAND (TREE_OPERAND (lhs, 0), 0);
+ if (DECL_P (decl)
+ && DECL_SIZE (decl) == TYPE_SIZE (TREE_TYPE (lhs))
+ && (TREE_THIS_VOLATILE (decl) == TREE_THIS_VOLATILE (lhs)))
+ return false;
+ }
+
+ return true;
+}
+
+/* When possible, clear TREE_ADDRESSABLE bit or set DECL_GIMPLE_REG_P bit and
+ mark the variable VAR for conversion into SSA. Return true when updating
+ stmts is required. */
+
+static bool
+maybe_optimize_var (tree var, bitmap addresses_taken, bitmap not_reg_needs)
+{
+ bool update_vops = false;
+
+ /* Global Variables, result decls cannot be changed. */
+ if (is_global_var (var)
+ || TREE_CODE (var) == RESULT_DECL
+ || bitmap_bit_p (addresses_taken, DECL_UID (var)))
+ return false;
+
+ /* If the variable is not in the list of referenced vars then we
+ do not need to touch it nor can we rename it. */
+ if (!referenced_var_lookup (cfun, DECL_UID (var)))
+ return false;
+
+ if (TREE_ADDRESSABLE (var)
+ /* Do not change TREE_ADDRESSABLE if we need to preserve var as
+ a non-register. Otherwise we are confused and forget to
+ add virtual operands for it. */
+ && (!is_gimple_reg_type (TREE_TYPE (var))
+ || TREE_CODE (TREE_TYPE (var)) == VECTOR_TYPE
+ || TREE_CODE (TREE_TYPE (var)) == COMPLEX_TYPE
+ || !bitmap_bit_p (not_reg_needs, DECL_UID (var))))
+ {
+ TREE_ADDRESSABLE (var) = 0;
+ if (is_gimple_reg (var))
+ mark_sym_for_renaming (var);
+ update_vops = true;
+ if (dump_file)
+ {
+ fprintf (dump_file, "No longer having address taken: ");
+ print_generic_expr (dump_file, var, 0);
+ fprintf (dump_file, "\n");
+ }
+ }
+
+ if (!DECL_GIMPLE_REG_P (var)
+ && !bitmap_bit_p (not_reg_needs, DECL_UID (var))
+ && (TREE_CODE (TREE_TYPE (var)) == COMPLEX_TYPE
+ || TREE_CODE (TREE_TYPE (var)) == VECTOR_TYPE)
+ && !TREE_THIS_VOLATILE (var)
+ && (TREE_CODE (var) != VAR_DECL || !DECL_HARD_REGISTER (var)))
+ {
+ DECL_GIMPLE_REG_P (var) = 1;
+ mark_sym_for_renaming (var);
+ update_vops = true;
+ if (dump_file)
+ {
+ fprintf (dump_file, "Now a gimple register: ");
+ print_generic_expr (dump_file, var, 0);
+ fprintf (dump_file, "\n");
+ }
+ }
+
+ return update_vops;
+}
+
+/* Compute TREE_ADDRESSABLE and DECL_GIMPLE_REG_P for local variables. */
+
+void
+execute_update_addresses_taken (void)
+{
+ gimple_stmt_iterator gsi;
+ basic_block bb;
+ bitmap addresses_taken = BITMAP_ALLOC (NULL);
+ bitmap not_reg_needs = BITMAP_ALLOC (NULL);
+ bool update_vops = false;
+ tree var;
+ unsigned i;
+
+ timevar_push (TV_ADDRESS_TAKEN);
+
+ /* Collect into ADDRESSES_TAKEN all variables whose address is taken within
+ the function body. */
+ FOR_EACH_BB (bb)
+ {
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ enum gimple_code code = gimple_code (stmt);
+ tree decl;
+
+ /* Note all addresses taken by the stmt. */
+ gimple_ior_addresses_taken (addresses_taken, stmt);
+
+ /* If we have a call or an assignment, see if the lhs contains
+ a local decl that requires not to be a gimple register. */
+ if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL)
+ {
+ tree lhs = gimple_get_lhs (stmt);
+ if (lhs
+ && TREE_CODE (lhs) != SSA_NAME
+ && non_rewritable_lvalue_p (lhs))
+ {
+ decl = get_base_address (lhs);
+ if (DECL_P (decl))
+ bitmap_set_bit (not_reg_needs, DECL_UID (decl));
+ }
+ }
+
+ if (gimple_assign_single_p (stmt))
+ {
+ tree rhs = gimple_assign_rhs1 (stmt);
+ if ((decl = non_rewritable_mem_ref_base (rhs)))
+ bitmap_set_bit (not_reg_needs, DECL_UID (decl));
+ }
+
+ else if (code == GIMPLE_CALL)
+ {
+ for (i = 0; i < gimple_call_num_args (stmt); ++i)
+ {
+ tree arg = gimple_call_arg (stmt, i);
+ if ((decl = non_rewritable_mem_ref_base (arg)))
+ bitmap_set_bit (not_reg_needs, DECL_UID (decl));
+ }
+ }
+
+ else if (code == GIMPLE_ASM)
+ {
+ for (i = 0; i < gimple_asm_noutputs (stmt); ++i)
+ {
+ tree link = gimple_asm_output_op (stmt, i);
+ tree lhs = TREE_VALUE (link);
+ if (TREE_CODE (lhs) != SSA_NAME)
+ {
+ decl = get_base_address (lhs);
+ if (DECL_P (decl)
+ && (non_rewritable_lvalue_p (lhs)
+ /* We cannot move required conversions from
+ the lhs to the rhs in asm statements, so
+ require we do not need any. */
+ || !useless_type_conversion_p
+ (TREE_TYPE (lhs), TREE_TYPE (decl))))
+ bitmap_set_bit (not_reg_needs, DECL_UID (decl));
+ }
+ }
+ for (i = 0; i < gimple_asm_ninputs (stmt); ++i)
+ {
+ tree link = gimple_asm_input_op (stmt, i);
+ if ((decl = non_rewritable_mem_ref_base (TREE_VALUE (link))))
+ bitmap_set_bit (not_reg_needs, DECL_UID (decl));
+ }
+ }
+ }
+
+ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ size_t i;
+ gimple phi = gsi_stmt (gsi);
+
+ for (i = 0; i < gimple_phi_num_args (phi); i++)
+ {
+ tree op = PHI_ARG_DEF (phi, i), var;
+ if (TREE_CODE (op) == ADDR_EXPR
+ && (var = get_base_address (TREE_OPERAND (op, 0))) != NULL
+ && DECL_P (var))
+ bitmap_set_bit (addresses_taken, DECL_UID (var));
+ }
+ }
+ }
+
+ /* We cannot iterate over all referenced vars because that can contain
+ unused vars from BLOCK trees, which causes code generation differences
+ for -g vs. -g0. */
+ for (var = DECL_ARGUMENTS (cfun->decl); var; var = DECL_CHAIN (var))
+ update_vops |= maybe_optimize_var (var, addresses_taken, not_reg_needs);
+
+ FOR_EACH_VEC_ELT (tree, cfun->local_decls, i, var)
+ update_vops |= maybe_optimize_var (var, addresses_taken, not_reg_needs);
+
+ /* Operand caches need to be recomputed for operands referencing the updated
+ variables. */
+ if (update_vops)
+ {
+ FOR_EACH_BB (bb)
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);)
+ {
+ gimple stmt = gsi_stmt (gsi);
+
+ /* Re-write TARGET_MEM_REFs of symbols we want to
+ rewrite into SSA form. */
+ if (gimple_assign_single_p (stmt))
+ {
+ tree lhs = gimple_assign_lhs (stmt);
+ tree rhs, *rhsp = gimple_assign_rhs1_ptr (stmt);
+ tree sym;
+
+ /* We shouldn't have any fancy wrapping of
+ component-refs on the LHS, but look through
+ VIEW_CONVERT_EXPRs as that is easy. */
+ while (TREE_CODE (lhs) == VIEW_CONVERT_EXPR)
+ lhs = TREE_OPERAND (lhs, 0);
+ if (TREE_CODE (lhs) == MEM_REF
+ && TREE_CODE (TREE_OPERAND (lhs, 0)) == ADDR_EXPR
+ && integer_zerop (TREE_OPERAND (lhs, 1))
+ && (sym = TREE_OPERAND (TREE_OPERAND (lhs, 0), 0))
+ && DECL_P (sym)
+ && !TREE_ADDRESSABLE (sym)
+ && symbol_marked_for_renaming (sym))
+ lhs = sym;
+ else
+ lhs = gimple_assign_lhs (stmt);
+
+ /* Rewrite the RHS and make sure the resulting assignment
+ is validly typed. */
+ maybe_rewrite_mem_ref_base (rhsp);
+ rhs = gimple_assign_rhs1 (stmt);
+ if (gimple_assign_lhs (stmt) != lhs
+ && !useless_type_conversion_p (TREE_TYPE (lhs),
+ TREE_TYPE (rhs)))
+ rhs = fold_build1 (VIEW_CONVERT_EXPR,
+ TREE_TYPE (lhs), rhs);
+
+ if (gimple_assign_lhs (stmt) != lhs)
+ gimple_assign_set_lhs (stmt, lhs);
+
+ /* For var ={v} {CLOBBER}; where var lost
+ TREE_ADDRESSABLE just remove the stmt. */
+ if (DECL_P (lhs)
+ && TREE_CLOBBER_P (rhs)
+ && symbol_marked_for_renaming (lhs))
+ {
+ unlink_stmt_vdef (stmt);
+ gsi_remove (&gsi, true);
+ release_defs (stmt);
+ continue;
+ }
+
+ if (gimple_assign_rhs1 (stmt) != rhs)
+ {
+ gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
+ gimple_assign_set_rhs_from_tree (&gsi, rhs);
+ }
+ }
+
+ else if (gimple_code (stmt) == GIMPLE_CALL)
+ {
+ unsigned i;
+ for (i = 0; i < gimple_call_num_args (stmt); ++i)
+ {
+ tree *argp = gimple_call_arg_ptr (stmt, i);
+ maybe_rewrite_mem_ref_base (argp);
+ }
+ }
+
+ else if (gimple_code (stmt) == GIMPLE_ASM)
+ {
+ unsigned i;
+ for (i = 0; i < gimple_asm_noutputs (stmt); ++i)
+ {
+ tree link = gimple_asm_output_op (stmt, i);
+ maybe_rewrite_mem_ref_base (&TREE_VALUE (link));
+ }
+ for (i = 0; i < gimple_asm_ninputs (stmt); ++i)
+ {
+ tree link = gimple_asm_input_op (stmt, i);
+ maybe_rewrite_mem_ref_base (&TREE_VALUE (link));
+ }
+ }
+
+ else if (gimple_debug_bind_p (stmt)
+ && gimple_debug_bind_has_value_p (stmt))
+ {
+ tree *valuep = gimple_debug_bind_get_value_ptr (stmt);
+ tree decl;
+ maybe_rewrite_mem_ref_base (valuep);
+ decl = non_rewritable_mem_ref_base (*valuep);
+ if (decl && symbol_marked_for_renaming (decl))
+ gimple_debug_bind_reset_value (stmt);
+ }
+
+ if (gimple_references_memory_p (stmt)
+ || is_gimple_debug (stmt))
+ update_stmt (stmt);
+
+ gsi_next (&gsi);
+ }
+
+ /* Update SSA form here, we are called as non-pass as well. */
+ if (number_of_loops () > 1 && loops_state_satisfies_p (LOOP_CLOSED_SSA))
+ rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
+ else
+ update_ssa (TODO_update_ssa);
+ }
+
+ BITMAP_FREE (not_reg_needs);
+ BITMAP_FREE (addresses_taken);
+ timevar_pop (TV_ADDRESS_TAKEN);
+}
+
+struct gimple_opt_pass pass_update_address_taken =
+{
+ {
+ GIMPLE_PASS,
+ "addressables", /* name */
+ NULL, /* gate */
+ NULL, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
- 0, /* tv_id */
+ TV_ADDRESS_TAKEN, /* tv_id */
PROP_ssa, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- 0, /* todo_flags_finish */
- 0 /* letter */
+ TODO_update_address_taken /* todo_flags_finish */
+ }
};
-
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