/* Convert a program in SSA form into Normal form.
- Copyright (C) 2004-2016 Free Software Foundation, Inc.
+ Copyright (C) 2004-2020 Free Software Foundation, Inc.
Contributed by Andrew Macleod <amacleod@redhat.com>
This file is part of GCC.
#include "gimple.h"
#include "cfghooks.h"
#include "ssa.h"
+#include "tree-ssa.h"
+#include "memmodel.h"
#include "emit-rtl.h"
#include "gimple-pretty-print.h"
#include "diagnostic-core.h"
+#include "tree-dfa.h"
#include "stor-layout.h"
#include "cfgrtl.h"
#include "cfganal.h"
return false;
/* If the statement may throw an exception, it cannot be replaced. */
- if (stmt_could_throw_p (stmt))
+ if (stmt_could_throw_p (cfun, stmt))
return false;
/* Punt if there is more than 1 def. */
rarely more than 6, and in the bootstrap of gcc, the maximum number
of nodes encountered was 12. */
-struct elim_graph
+class elim_graph
{
+public:
elim_graph (var_map map);
/* Size of the elimination vectors. */
auto_vec<int> edge_list;
/* Source locus on each edge */
- auto_vec<source_location> edge_locus;
+ auto_vec<location_t> edge_locus;
/* Visited vector. */
auto_sbitmap visited;
auto_vec<tree> const_copies;
/* Source locations for any constant copies. */
- auto_vec<source_location> copy_locus;
+ auto_vec<location_t> copy_locus;
};
use its location. Otherwise search instructions in predecessors
of E for a location, and use that one. That makes sense because
we insert on edges for PHI nodes, and effects of PHIs happen on
- the end of the predecessor conceptually. */
+ the end of the predecessor conceptually. An exception is made
+ for EH edges because we don't want to drag the source location
+ of unrelated statements at the beginning of handlers; they would
+ be further reused for various EH constructs, which would damage
+ the coverage information. */
static void
set_location_for_edge (edge e)
{
if (e->goto_locus)
+ set_curr_insn_location (e->goto_locus);
+ else if (e->flags & EDGE_EH)
{
- set_curr_insn_location (e->goto_locus);
+ basic_block bb = e->dest;
+ gimple_stmt_iterator gsi;
+
+ do
+ {
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple *stmt = gsi_stmt (gsi);
+ if (is_gimple_debug (stmt))
+ continue;
+ if (gimple_has_location (stmt) || gimple_block (stmt))
+ {
+ set_curr_insn_location (gimple_location (stmt));
+ return;
+ }
+ }
+ /* Nothing found in this basic block. Make a half-assed attempt
+ to continue with another block. */
+ if (single_succ_p (bb))
+ bb = single_succ (bb);
+ else
+ bb = e->dest;
+ }
+ while (bb != e->dest);
}
else
{
/* Insert a copy instruction from partition SRC to DEST onto edge E. */
static void
-insert_partition_copy_on_edge (edge e, int dest, int src, source_location locus)
+insert_partition_copy_on_edge (edge e, int dest, int src, location_t locus)
{
tree var;
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file,
- "Inserting a partition copy on edge BB%d->BB%d :"
+ "Inserting a partition copy on edge BB%d->BB%d : "
"PART.%d = PART.%d",
e->src->index,
e->dest->index, dest, src);
onto edge E. */
static void
-insert_value_copy_on_edge (edge e, int dest, tree src, source_location locus)
+insert_value_copy_on_edge (edge e, int dest, tree src, location_t locus)
{
rtx dest_rtx, seq, x;
machine_mode dest_mode, src_mode;
static void
insert_rtx_to_part_on_edge (edge e, int dest, rtx src, int unsignedsrcp,
- source_location locus)
+ location_t locus)
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
onto edge E. */
static void
-insert_part_to_rtx_on_edge (edge e, rtx dest, int src, source_location locus)
+insert_part_to_rtx_on_edge (edge e, rtx dest, int src, location_t locus)
{
tree var;
if (dump_file && (dump_flags & TDF_DETAILS))
/* Add the edge PRED->SUCC to graph G. */
static inline void
-elim_graph_add_edge (elim_graph *g, int pred, int succ, source_location locus)
+elim_graph_add_edge (elim_graph *g, int pred, int succ, location_t locus)
{
g->edge_list.safe_push (pred);
g->edge_list.safe_push (succ);
return the successor node. -1 is returned if there is no such edge. */
static inline int
-elim_graph_remove_succ_edge (elim_graph *g, int node, source_location *locus)
+elim_graph_remove_succ_edge (elim_graph *g, int node, location_t *locus)
{
int y;
unsigned x;
for (gsi = gsi_start_phis (g->e->dest); !gsi_end_p (gsi); gsi_next (&gsi))
{
gphi *phi = gsi.phi ();
- source_location locus;
+ location_t locus;
p0 = var_to_partition (g->map, gimple_phi_result (phi));
/* Ignore results which are not in partitions. */
continue;
Ti = PHI_ARG_DEF (phi, g->e->dest_idx);
- locus = gimple_phi_arg_location_from_edge (phi, g->e);
+ /* See set_location_for_edge for the rationale. */
+ if (g->e->flags & EDGE_EH)
+ locus = UNKNOWN_LOCATION;
+ else
+ locus = gimple_phi_arg_location_from_edge (phi, g->e);
/* If this argument is a constant, or a SSA_NAME which is being
left in SSA form, just queue a copy to be emitted on this
elim_forward (elim_graph *g, int T)
{
int S;
- source_location locus;
+ location_t locus;
bitmap_set_bit (g->visited, T);
FOR_EACH_ELIM_GRAPH_SUCC (g, T, S, locus,
elim_unvisited_predecessor (elim_graph *g, int T)
{
int P;
- source_location locus;
+ location_t locus;
FOR_EACH_ELIM_GRAPH_PRED (g, T, P, locus,
{
elim_backward (elim_graph *g, int T)
{
int P;
- source_location locus;
+ location_t locus;
bitmap_set_bit (g->visited, T);
FOR_EACH_ELIM_GRAPH_PRED (g, T, P, locus,
tree type = TREE_TYPE (name);
int unsignedp;
machine_mode reg_mode = promote_ssa_mode (name, &unsignedp);
+ if (reg_mode == BLKmode)
+ return assign_temp (type, 0, 0);
rtx x = gen_reg_rtx (reg_mode);
if (POINTER_TYPE_P (type))
mark_reg_pointer (x, TYPE_ALIGN (TREE_TYPE (type)));
elim_create (elim_graph *g, int T)
{
int P, S;
- source_location locus;
+ location_t locus;
if (elim_unvisited_predecessor (g, T))
{
{
int dest;
tree src;
- source_location locus;
+ location_t locus;
src = g->const_copies.pop ();
dest = g->const_dests.pop ();
gphi *phi = gsi.phi ();
result = gimple_phi_result (phi);
if (virtual_operand_p (result))
- {
- /* There should be no arguments which are not virtual, or the
- results will be incorrect. */
- if (flag_checking)
- for (size_t i = 0; i < gimple_phi_num_args (phi); i++)
- {
- tree arg = PHI_ARG_DEF (phi, i);
- if (TREE_CODE (arg) == SSA_NAME
- && !virtual_operand_p (arg))
- {
- fprintf (stderr, "Argument of PHI is not virtual (");
- print_generic_expr (stderr, arg, TDF_SLIM);
- fprintf (stderr, "), but the result is :");
- print_gimple_stmt (stderr, phi, 0, TDF_SLIM);
- internal_error ("SSA corruption");
- }
- }
-
- remove_phi_node (&gsi, true);
- }
+ remove_phi_node (&gsi, true);
else
{
/* Also remove real PHIs with no uses. */
}
}
+/* Create a default def for VAR. */
+
+static void
+create_default_def (tree var, void *arg ATTRIBUTE_UNUSED)
+{
+ if (!is_gimple_reg (var))
+ return;
+
+ tree ssa = get_or_create_ssa_default_def (cfun, var);
+ gcc_assert (ssa);
+}
+
+/* Call CALLBACK for all PARM_DECLs and RESULT_DECLs for which
+ assign_parms may ask for a default partition. */
+
+static void
+for_all_parms (void (*callback)(tree var, void *arg), void *arg)
+{
+ for (tree var = DECL_ARGUMENTS (current_function_decl); var;
+ var = DECL_CHAIN (var))
+ callback (var, arg);
+ if (!VOID_TYPE_P (TREE_TYPE (DECL_RESULT (current_function_decl))))
+ callback (DECL_RESULT (current_function_decl), arg);
+ if (cfun->static_chain_decl)
+ callback (cfun->static_chain_decl, arg);
+}
+
+/* We need to pass two arguments to set_parm_default_def_partition,
+ but for_all_parms only supports one. Use a pair. */
+
+typedef std::pair<var_map, bitmap> parm_default_def_partition_arg;
+
+/* Set in ARG's PARTS bitmap the bit corresponding to the partition in
+ ARG's MAP containing VAR's default def. */
+
+static void
+set_parm_default_def_partition (tree var, void *arg_)
+{
+ parm_default_def_partition_arg *arg = (parm_default_def_partition_arg *)arg_;
+ var_map map = arg->first;
+ bitmap parts = arg->second;
+
+ if (!is_gimple_reg (var))
+ return;
+
+ tree ssa = ssa_default_def (cfun, var);
+ gcc_assert (ssa);
+
+ int version = var_to_partition (map, ssa);
+ gcc_assert (version != NO_PARTITION);
+
+ bool changed = bitmap_set_bit (parts, version);
+ gcc_assert (changed);
+}
+
+/* Allocate and return a bitmap that has a bit set for each partition
+ that contains a default def for a parameter. */
+
+static bitmap
+get_parm_default_def_partitions (var_map map)
+{
+ bitmap parm_default_def_parts = BITMAP_ALLOC (NULL);
+
+ parm_default_def_partition_arg
+ arg = std::make_pair (map, parm_default_def_parts);
+
+ for_all_parms (set_parm_default_def_partition, &arg);
+
+ return parm_default_def_parts;
+}
+
+/* Allocate and return a bitmap that has a bit set for each partition
+ that contains an undefined value. */
+
+static bitmap
+get_undefined_value_partitions (var_map map)
+{
+ bitmap undefined_value_parts = BITMAP_ALLOC (NULL);
+
+ for (unsigned int i = 1; i < num_ssa_names; i++)
+ {
+ tree var = ssa_name (i);
+ if (var
+ && !virtual_operand_p (var)
+ && !has_zero_uses (var)
+ && ssa_undefined_value_p (var))
+ {
+ const int p = var_to_partition (map, var);
+ if (p != NO_PARTITION)
+ bitmap_set_bit (undefined_value_parts, p);
+ }
+ }
+
+ return undefined_value_parts;
+}
+
/* Given the out-of-ssa info object SA (with prepared partitions)
eliminate all phi nodes in all basic blocks. Afterwards no
basic block will have phi nodes anymore and there are possibly
bitmap values = NULL;
var_map map;
- map = coalesce_ssa_name ();
+ for_all_parms (create_default_def, NULL);
+ map = init_var_map (num_ssa_names);
+ coalesce_ssa_name (map);
/* Return to viewing the variable list as just all reference variables after
coalescing has been performed. */
sa->map = map;
sa->values = values;
sa->partitions_for_parm_default_defs = get_parm_default_def_partitions (map);
+ sa->partitions_for_undefined_values = get_undefined_value_partitions (map);
}
{
tree arg = gimple_phi_arg_def (phi, i);
edge e = gimple_phi_arg_edge (phi, i);
+ /* We are only interested in copies emitted on critical
+ backedges. */
+ if (!(e->flags & EDGE_DFS_BACK)
+ || !EDGE_CRITICAL_P (e))
+ continue;
/* If the argument is not an SSA_NAME, then we will need a
- constant initialization. If the argument is an SSA_NAME with
- a different underlying variable then a copy statement will be
- needed. */
- if ((e->flags & EDGE_DFS_BACK)
- && (TREE_CODE (arg) != SSA_NAME
- || SSA_NAME_VAR (arg) != SSA_NAME_VAR (result)
- || trivially_conflicts_p (bb, result, arg)))
+ constant initialization. If the argument is an SSA_NAME then
+ a copy statement may be needed. First handle the case
+ where we cannot insert before the argument definition. */
+ if (TREE_CODE (arg) != SSA_NAME
+ || (gimple_code (SSA_NAME_DEF_STMT (arg)) == GIMPLE_PHI
+ && trivially_conflicts_p (bb, result, arg)))
{
tree name;
gassign *stmt;
gsi_insert_after (&gsi2, stmt, GSI_NEW_STMT);
SET_PHI_ARG_DEF (phi, i, name);
}
+ /* Insert a copy before the definition of the backedge value
+ and adjust all conflicting uses. */
+ else if (trivially_conflicts_p (bb, result, arg))
+ {
+ gimple *def = SSA_NAME_DEF_STMT (arg);
+ if (gimple_nop_p (def)
+ || gimple_code (def) == GIMPLE_PHI)
+ continue;
+ tree name = copy_ssa_name (result);
+ gimple *stmt = gimple_build_assign (name, result);
+ imm_use_iterator imm_iter;
+ gimple *use_stmt;
+ /* The following matches trivially_conflicts_p. */
+ FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, result)
+ {
+ if (gimple_bb (use_stmt) != bb
+ || (gimple_code (use_stmt) != GIMPLE_PHI
+ && (maybe_renumber_stmts_bb (bb), true)
+ && gimple_uid (use_stmt) > gimple_uid (def)))
+ {
+ use_operand_p use;
+ FOR_EACH_IMM_USE_ON_STMT (use, imm_iter)
+ SET_USE (use, name);
+ }
+ }
+ gimple_stmt_iterator gsi = gsi_for_stmt (def);
+ gsi_insert_before (&gsi, stmt, GSI_SAME_STMT);
+ }
}
}
BITMAP_FREE (sa->values);
delete_var_map (sa->map);
BITMAP_FREE (sa->partitions_for_parm_default_defs);
+ BITMAP_FREE (sa->partitions_for_undefined_values);
memset (sa, 0, sizeof *sa);
}
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