/* Convert a program in SSA form into Normal form.
- Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010
- Free Software Foundation, Inc.
+ Copyright (C) 2004-2017 Free Software Foundation, Inc.
Contributed by Andrew Macleod <amacleod@redhat.com>
This file is part of GCC.
#include "config.h"
#include "system.h"
#include "coretypes.h"
-#include "tm.h"
+#include "backend.h"
+#include "rtl.h"
#include "tree.h"
-#include "ggc.h"
-#include "basic-block.h"
+#include "gimple.h"
+#include "cfghooks.h"
+#include "ssa.h"
+#include "memmodel.h"
+#include "emit-rtl.h"
#include "gimple-pretty-print.h"
-#include "bitmap.h"
-#include "tree-flow.h"
-#include "dumpfile.h"
#include "diagnostic-core.h"
-#include "ssaexpand.h"
+#include "stor-layout.h"
+#include "cfgrtl.h"
+#include "cfganal.h"
+#include "tree-eh.h"
+#include "gimple-iterator.h"
+#include "tree-cfg.h"
+#include "dumpfile.h"
+#include "tree-ssa-live.h"
+#include "tree-ssa-ter.h"
+#include "tree-ssa-coalesce.h"
+#include "tree-outof-ssa.h"
+#include "dojump.h"
/* FIXME: A lot of code here deals with expanding to RTL. All that code
should be in cfgexpand.c. */
+#include "explow.h"
#include "expr.h"
+/* Return TRUE if expression STMT is suitable for replacement. */
+
+bool
+ssa_is_replaceable_p (gimple *stmt)
+{
+ use_operand_p use_p;
+ tree def;
+ gimple *use_stmt;
+
+ /* Only consider modify stmts. */
+ if (!is_gimple_assign (stmt))
+ return false;
+
+ /* If the statement may throw an exception, it cannot be replaced. */
+ if (stmt_could_throw_p (stmt))
+ return false;
+
+ /* Punt if there is more than 1 def. */
+ def = SINGLE_SSA_TREE_OPERAND (stmt, SSA_OP_DEF);
+ if (!def)
+ return false;
+
+ /* Only consider definitions which have a single use. */
+ if (!single_imm_use (def, &use_p, &use_stmt))
+ return false;
+
+ /* Used in this block, but at the TOP of the block, not the end. */
+ if (gimple_code (use_stmt) == GIMPLE_PHI)
+ return false;
+
+ /* There must be no VDEFs. */
+ if (gimple_vdef (stmt))
+ return false;
+
+ /* Float expressions must go through memory if float-store is on. */
+ if (flag_float_store
+ && FLOAT_TYPE_P (gimple_expr_type (stmt)))
+ return false;
+
+ /* An assignment with a register variable on the RHS is not
+ replaceable. */
+ if (gimple_assign_rhs_code (stmt) == VAR_DECL
+ && DECL_HARD_REGISTER (gimple_assign_rhs1 (stmt)))
+ return false;
+
+ /* No function calls can be replaced. */
+ if (is_gimple_call (stmt))
+ return false;
+
+ /* Leave any stmt with volatile operands alone as well. */
+ if (gimple_has_volatile_ops (stmt))
+ return false;
+
+ return true;
+}
/* Used to hold all the components required to do SSA PHI elimination.
rarely more than 6, and in the bootstrap of gcc, the maximum number
of nodes encountered was 12. */
-typedef struct _elim_graph {
+struct elim_graph
+{
+ elim_graph (var_map map);
+
/* Size of the elimination vectors. */
int size;
/* List of nodes in the elimination graph. */
- vec<int> nodes;
+ auto_vec<int> nodes;
/* The predecessor and successor edge list. */
- vec<int> edge_list;
+ auto_vec<int> edge_list;
/* Source locus on each edge */
- vec<source_location> edge_locus;
+ auto_vec<source_location> edge_locus;
/* Visited vector. */
- sbitmap visited;
+ auto_sbitmap visited;
/* Stack for visited nodes. */
- vec<int> stack;
+ auto_vec<int> stack;
/* The variable partition map. */
var_map map;
edge e;
/* List of constant copies to emit. These are pushed on in pairs. */
- vec<int> const_dests;
- vec<tree> const_copies;
+ auto_vec<int> const_dests;
+ auto_vec<tree> const_copies;
/* Source locations for any constant copies. */
- vec<source_location> copy_locus;
-} *elim_graph;
+ auto_vec<source_location> copy_locus;
+};
/* For an edge E find out a good source location to associate with
{
for (gsi = gsi_last_bb (bb); !gsi_end_p (gsi); gsi_prev (&gsi))
{
- gimple stmt = gsi_stmt (gsi);
+ gimple *stmt = gsi_stmt (gsi);
if (is_gimple_debug (stmt))
continue;
if (gimple_has_location (stmt) || gimple_block (stmt))
SRC/DEST might be BLKmode memory locations SIZEEXP is a tree from
which we deduce the size to copy in that case. */
-static inline rtx
+static inline rtx_insn *
emit_partition_copy (rtx dest, rtx src, int unsignedsrcp, tree sizeexp)
{
- rtx seq;
-
start_sequence ();
if (GET_MODE (src) != VOIDmode && GET_MODE (src) != GET_MODE (dest))
}
else
emit_move_insn (dest, src);
+ do_pending_stack_adjust ();
- seq = get_insns ();
+ rtx_insn *seq = get_insns ();
end_sequence ();
return seq;
insert_partition_copy_on_edge (edge e, int dest, int src, source_location locus)
{
tree var;
- rtx seq;
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);
set_curr_insn_location (locus);
var = partition_to_var (SA.map, src);
- seq = emit_partition_copy (SA.partition_to_pseudo[dest],
- SA.partition_to_pseudo[src],
- TYPE_UNSIGNED (TREE_TYPE (var)),
- var);
+ rtx_insn *seq = emit_partition_copy (copy_rtx (SA.partition_to_pseudo[dest]),
+ copy_rtx (SA.partition_to_pseudo[src]),
+ TYPE_UNSIGNED (TREE_TYPE (var)),
+ var);
insert_insn_on_edge (seq, e);
}
static void
insert_value_copy_on_edge (edge e, int dest, tree src, source_location locus)
{
- rtx seq, x;
- enum machine_mode dest_mode, src_mode;
+ rtx dest_rtx, seq, x;
+ machine_mode dest_mode, src_mode;
int unsignedp;
- tree var;
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "\n");
}
- gcc_assert (SA.partition_to_pseudo[dest]);
+ dest_rtx = copy_rtx (SA.partition_to_pseudo[dest]);
+ gcc_assert (dest_rtx);
set_location_for_edge (e);
/* If a locus is provided, override the default. */
start_sequence ();
- var = SSA_NAME_VAR (partition_to_var (SA.map, dest));
+ tree name = partition_to_var (SA.map, dest);
src_mode = TYPE_MODE (TREE_TYPE (src));
- dest_mode = GET_MODE (SA.partition_to_pseudo[dest]);
- gcc_assert (src_mode == TYPE_MODE (TREE_TYPE (var)));
- gcc_assert (!REG_P (SA.partition_to_pseudo[dest])
- || dest_mode == promote_decl_mode (var, &unsignedp));
+ dest_mode = GET_MODE (dest_rtx);
+ gcc_assert (src_mode == TYPE_MODE (TREE_TYPE (name)));
+ gcc_assert (!REG_P (dest_rtx)
+ || dest_mode == promote_ssa_mode (name, &unsignedp));
if (src_mode != dest_mode)
{
}
else if (src_mode == BLKmode)
{
- x = SA.partition_to_pseudo[dest];
- store_expr (src, x, 0, false);
+ x = dest_rtx;
+ store_expr (src, x, 0, false, false);
}
else
- x = expand_expr (src, SA.partition_to_pseudo[dest],
- dest_mode, EXPAND_NORMAL);
+ x = expand_expr (src, dest_rtx, dest_mode, EXPAND_NORMAL);
+
+ if (x != dest_rtx)
+ emit_move_insn (dest_rtx, x);
+ do_pending_stack_adjust ();
- if (x != SA.partition_to_pseudo[dest])
- emit_move_insn (SA.partition_to_pseudo[dest], x);
seq = get_insns ();
end_sequence ();
insert_rtx_to_part_on_edge (edge e, int dest, rtx src, int unsignedsrcp,
source_location locus)
{
- rtx seq;
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file,
mems. Usually we give the source. As we result from SSA names
the left and right size should be the same (and no WITH_SIZE_EXPR
involved), so it doesn't matter. */
- seq = emit_partition_copy (SA.partition_to_pseudo[dest],
- src, unsignedsrcp,
- partition_to_var (SA.map, dest));
+ rtx_insn *seq = emit_partition_copy (copy_rtx (SA.partition_to_pseudo[dest]),
+ src, unsignedsrcp,
+ partition_to_var (SA.map, dest));
insert_insn_on_edge (seq, e);
}
insert_part_to_rtx_on_edge (edge e, rtx dest, int src, source_location locus)
{
tree var;
- rtx seq;
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file,
set_curr_insn_location (locus);
var = partition_to_var (SA.map, src);
- seq = emit_partition_copy (dest,
- SA.partition_to_pseudo[src],
- TYPE_UNSIGNED (TREE_TYPE (var)),
- var);
+ rtx_insn *seq = emit_partition_copy (dest,
+ copy_rtx (SA.partition_to_pseudo[src]),
+ TYPE_UNSIGNED (TREE_TYPE (var)),
+ var);
insert_insn_on_edge (seq, e);
}
-/* Create an elimination graph with SIZE nodes and associated data
- structures. */
+/* Create an elimination graph for map. */
-static elim_graph
-new_elim_graph (int size)
+elim_graph::elim_graph (var_map map) :
+ nodes (30), edge_list (20), edge_locus (10), visited (map->num_partitions),
+ stack (30), map (map), const_dests (20), const_copies (20), copy_locus (10)
{
- elim_graph g = (elim_graph) xmalloc (sizeof (struct _elim_graph));
-
- g->nodes.create (30);
- g->const_dests.create (20);
- g->const_copies.create (20);
- g->copy_locus.create (10);
- g->edge_list.create (20);
- g->edge_locus.create (10);
- g->stack.create (30);
-
- g->visited = sbitmap_alloc (size);
-
- return g;
}
/* Empty elimination graph G. */
static inline void
-clear_elim_graph (elim_graph g)
+clear_elim_graph (elim_graph *g)
{
g->nodes.truncate (0);
g->edge_list.truncate (0);
}
-/* Delete elimination graph G. */
-
-static inline void
-delete_elim_graph (elim_graph g)
-{
- sbitmap_free (g->visited);
- g->stack.release ();
- g->edge_list.release ();
- g->const_copies.release ();
- g->const_dests.release ();
- g->nodes.release ();
- g->copy_locus.release ();
- g->edge_locus.release ();
-
- free (g);
-}
-
-
/* Return the number of nodes in graph G. */
static inline int
-elim_graph_size (elim_graph g)
+elim_graph_size (elim_graph *g)
{
return g->nodes.length ();
}
/* Add NODE to graph G, if it doesn't exist already. */
static inline void
-elim_graph_add_node (elim_graph g, int node)
+elim_graph_add_node (elim_graph *g, int node)
{
int x;
int t;
/* 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, source_location 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, source_location *locus)
{
int y;
unsigned x;
/* Add T to elimination graph G. */
static inline void
-eliminate_name (elim_graph g, int T)
+eliminate_name (elim_graph *g, int T)
{
elim_graph_add_node (g, T);
}
+/* Return true if this phi argument T should have a copy queued when using
+ var_map MAP. PHI nodes should contain only ssa_names and invariants. A
+ test for ssa_name is definitely simpler, but don't let invalid contents
+ slip through in the meantime. */
+
+static inline bool
+queue_phi_copy_p (var_map map, tree t)
+{
+ if (TREE_CODE (t) == SSA_NAME)
+ {
+ if (var_to_partition (map, t) == NO_PARTITION)
+ return true;
+ return false;
+ }
+ gcc_checking_assert (is_gimple_min_invariant (t));
+ return true;
+}
/* Build elimination graph G for basic block BB on incoming PHI edge
G->e. */
static void
-eliminate_build (elim_graph g)
+eliminate_build (elim_graph *g)
{
tree Ti;
int p0, pi;
- gimple_stmt_iterator gsi;
+ gphi_iterator gsi;
clear_elim_graph (g);
for (gsi = gsi_start_phis (g->e->dest); !gsi_end_p (gsi); gsi_next (&gsi))
{
- gimple phi = gsi_stmt (gsi);
+ gphi *phi = gsi.phi ();
source_location locus;
p0 = var_to_partition (g->map, gimple_phi_result (phi));
/* 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
edge. */
- if (!phi_ssa_name_p (Ti)
- || (TREE_CODE (Ti) == SSA_NAME
- && var_to_partition (g->map, Ti) == NO_PARTITION))
+ if (queue_phi_copy_p (g->map, Ti))
{
/* Save constant copies until all other copies have been emitted
on this edge. */
/* Push successors of T onto the elimination stack for G. */
static void
-elim_forward (elim_graph g, int T)
+elim_forward (elim_graph *g, int T)
{
int S;
source_location locus;
/* Return 1 if there unvisited predecessors of T in graph G. */
static int
-elim_unvisited_predecessor (elim_graph g, int T)
+elim_unvisited_predecessor (elim_graph *g, int T)
{
int P;
source_location locus;
/* Process predecessors first, and insert a copy. */
static void
-elim_backward (elim_graph g, int T)
+elim_backward (elim_graph *g, int T)
{
int P;
source_location locus;
static rtx
get_temp_reg (tree name)
{
- tree var = TREE_CODE (name) == SSA_NAME ? SSA_NAME_VAR (name) : name;
- tree type = TREE_TYPE (var);
+ tree type = TREE_TYPE (name);
int unsignedp;
- enum machine_mode reg_mode = promote_decl_mode (var, &unsignedp);
+ machine_mode reg_mode = promote_ssa_mode (name, &unsignedp);
rtx x = gen_reg_rtx (reg_mode);
if (POINTER_TYPE_P (type))
- mark_reg_pointer (x, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (var))));
+ mark_reg_pointer (x, TYPE_ALIGN (TREE_TYPE (type)));
return x;
}
region, and create a temporary to break the cycle if one is found. */
static void
-elim_create (elim_graph g, int T)
+elim_create (elim_graph *g, int T)
{
int P, S;
source_location locus;
/* Eliminate all the phi nodes on edge E in graph G. */
static void
-eliminate_phi (edge e, elim_graph g)
+eliminate_phi (edge e, elim_graph *g)
{
int x;
check to see if this allows another PHI node to be removed. */
static void
-remove_gimple_phi_args (gimple phi)
+remove_gimple_phi_args (gphi *phi)
{
use_operand_p arg_p;
ssa_op_iter iter;
SET_USE (arg_p, NULL_TREE);
if (has_zero_uses (arg))
{
- gimple stmt;
+ gimple *stmt;
gimple_stmt_iterator gsi;
stmt = SSA_NAME_DEF_STMT (arg);
/* Also remove the def if it is a PHI node. */
if (gimple_code (stmt) == GIMPLE_PHI)
{
- remove_gimple_phi_args (stmt);
+ remove_gimple_phi_args (as_a <gphi *> (stmt));
gsi = gsi_for_stmt (stmt);
remove_phi_node (&gsi, true);
}
eliminate_useless_phis (void)
{
basic_block bb;
- gimple_stmt_iterator gsi;
+ gphi_iterator gsi;
tree result;
- FOR_EACH_BB (bb)
+ FOR_EACH_BB_FN (bb, cfun)
{
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); )
{
- gimple phi = gsi_stmt (gsi);
+ gphi *phi = gsi.phi ();
result = gimple_phi_result (phi);
if (virtual_operand_p (result))
{
-#ifdef ENABLE_CHECKING
- size_t i;
/* There should be no arguments which are not virtual, or the
results will be incorrect. */
- for (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");
- }
- }
-#endif
+ 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);
}
else
variable. */
static void
-rewrite_trees (var_map map ATTRIBUTE_UNUSED)
+rewrite_trees (var_map map)
{
-#ifdef ENABLE_CHECKING
+ if (!flag_checking)
+ return;
+
basic_block bb;
/* Search for PHIs where the destination has no partition, but one
or more arguments has a partition. This should not happen and can
create incorrect code. */
- FOR_EACH_BB (bb)
+ FOR_EACH_BB_FN (bb, cfun)
{
- gimple_stmt_iterator gsi;
+ gphi_iterator gsi;
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
- gimple phi = gsi_stmt (gsi);
+ gphi *phi = gsi.phi ();
tree T0 = var_to_partition_to_var (map, gimple_phi_result (phi));
if (T0 == NULL_TREE)
{
}
}
}
-#endif
}
/* Given the out-of-ssa info object SA (with prepared partitions)
expand_phi_nodes (struct ssaexpand *sa)
{
basic_block bb;
- elim_graph g = new_elim_graph (sa->map->num_partitions);
- g->map = sa->map;
+ elim_graph g (sa->map);
- FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR, next_bb)
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb,
+ EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb)
if (!gimple_seq_empty_p (phi_nodes (bb)))
{
edge e;
edge_iterator ei;
FOR_EACH_EDGE (e, ei, bb->preds)
- eliminate_phi (e, g);
+ eliminate_phi (e, &g);
set_phi_nodes (bb, NULL);
/* We can't redirect EH edges in RTL land, so we need to do this
here. Redirection happens only when splitting is necessary,
if (e->insns.r && (e->flags & EDGE_EH)
&& !single_pred_p (e->dest))
{
- rtx insns = e->insns.r;
+ rtx_insn *insns = e->insns.r;
basic_block bb;
- e->insns.r = NULL_RTX;
+ e->insns.r = NULL;
bb = split_edge (e);
single_pred_edge (bb)->insns.r = insns;
}
ei_next (&ei);
}
}
-
- delete_elim_graph (g);
}
{
bitmap values = NULL;
var_map map;
- unsigned i;
map = coalesce_ssa_name ();
/* Return to viewing the variable list as just all reference variables after
coalescing has been performed. */
- partition_view_normal (map, false);
+ partition_view_normal (map);
if (dump_file && (dump_flags & TDF_DETAILS))
{
sa->map = map;
sa->values = values;
- sa->partition_has_default_def = BITMAP_ALLOC (NULL);
- for (i = 1; i < num_ssa_names; i++)
- {
- tree t = ssa_name (i);
- if (t && SSA_NAME_IS_DEFAULT_DEF (t))
- {
- int p = var_to_partition (map, t);
- if (p != NO_PARTITION)
- bitmap_set_bit (sa->partition_has_default_def, p);
- }
- }
+ sa->partitions_for_parm_default_defs = get_parm_default_def_partitions (map);
+ sa->partitions_for_undefined_values = get_undefined_value_partitions (map);
}
bb->aux = NULL;
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
- gimple stmt = gsi_stmt (gsi);
+ gimple *stmt = gsi_stmt (gsi);
gimple_set_uid (stmt, i);
i++;
}
{
use_operand_p use;
imm_use_iterator imm_iter;
- gimple defa = SSA_NAME_DEF_STMT (arg);
+ gimple *defa = SSA_NAME_DEF_STMT (arg);
/* If ARG isn't defined in the same block it's too complicated for
our little mind. */
FOR_EACH_IMM_USE_FAST (use, imm_iter, result)
{
- gimple use_stmt = USE_STMT (use);
+ gimple *use_stmt = USE_STMT (use);
if (is_gimple_debug (use_stmt))
continue;
/* Now, if there's a use of RESULT that lies outside this basic block,
insert_backedge_copies (void)
{
basic_block bb;
- gimple_stmt_iterator gsi;
+ gphi_iterator gsi;
mark_dfs_back_edges ();
- FOR_EACH_BB (bb)
+ FOR_EACH_BB_FN (bb, cfun)
{
/* Mark block as possibly needing calculation of UIDs. */
bb->aux = &bb->aux;
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
- gimple phi = gsi_stmt (gsi);
+ gphi *phi = gsi.phi ();
tree result = gimple_phi_result (phi);
size_t i;
|| trivially_conflicts_p (bb, result, arg)))
{
tree name;
- gimple stmt, last = NULL;
+ gassign *stmt;
+ gimple *last = NULL;
gimple_stmt_iterator gsi2;
gsi2 = gsi_last_bb (gimple_phi_arg_edge (phi, i)->src);
/* Create a new instance of the underlying variable of the
PHI result. */
- name = copy_ssa_name (result, NULL);
+ name = copy_ssa_name (result);
stmt = gimple_build_assign (name,
gimple_phi_arg_def (phi, i));
if (sa->values)
BITMAP_FREE (sa->values);
delete_var_map (sa->map);
- BITMAP_FREE (sa->partition_has_default_def);
+ BITMAP_FREE (sa->partitions_for_parm_default_defs);
+ BITMAP_FREE (sa->partitions_for_undefined_values);
memset (sa, 0, sizeof *sa);
}
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