/* Convert a program in SSA form into Normal form.
- Copyright (C) 2004 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
Contributed by Andrew Macleod <amacleod@redhat.com>
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, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
-#include "flags.h"
-#include "rtl.h"
-#include "tm_p.h"
#include "ggc.h"
-#include "langhooks.h"
-#include "hard-reg-set.h"
#include "basic-block.h"
-#include "output.h"
-#include "errors.h"
-#include "expr.h"
-#include "function.h"
#include "diagnostic.h"
#include "bitmap.h"
#include "tree-flow.h"
-#include "tree-gimple.h"
-#include "tree-inline.h"
-#include "varray.h"
#include "timevar.h"
-#include "tree-alias-common.h"
-#include "hashtab.h"
#include "tree-dump.h"
-#include "tree-ssa-live.h"
#include "tree-pass.h"
+#include "toplev.h"
+#include "expr.h"
+#include "ssaexpand.h"
+
/* Used to hold all the components required to do SSA PHI elimination.
The node and pred/succ list is a simple linear list of nodes and
int size;
/* List of nodes in the elimination graph. */
- varray_type nodes;
+ VEC(int,heap) *nodes;
/* The predecessor and successor edge list. */
- varray_type edge_list;
+ VEC(int,heap) *edge_list;
/* Visited vector. */
sbitmap visited;
/* Stack for visited nodes. */
- varray_type stack;
+ VEC(int,heap) *stack;
/* The variable partition map. */
var_map map;
edge e;
/* List of constant copies to emit. These are pushed on in pairs. */
- varray_type const_copies;
+ VEC(int,heap) *const_dests;
+ VEC(tree,heap) *const_copies;
} *elim_graph;
-/* Local functions. */
-static tree create_temp (tree);
-static void insert_copy_on_edge (edge, tree, tree);
-static elim_graph new_elim_graph (int);
-static inline void delete_elim_graph (elim_graph);
-static inline void clear_elim_graph (elim_graph);
-static inline int elim_graph_size (elim_graph);
-static inline void elim_graph_add_node (elim_graph, tree);
-static inline void elim_graph_add_edge (elim_graph, int, int);
-static inline int elim_graph_remove_succ_edge (elim_graph, int);
-
-static inline void eliminate_name (elim_graph, tree);
-static void eliminate_build (elim_graph, basic_block, int);
-static void elim_forward (elim_graph, int);
-static int elim_unvisited_predecessor (elim_graph, int);
-static void elim_backward (elim_graph, int);
-static void elim_create (elim_graph, int);
-static void eliminate_phi (edge, int, elim_graph);
-static tree_live_info_p coalesce_ssa_name (var_map, int);
-static void assign_vars (var_map);
-static bool replace_use_variable (var_map, use_operand_p, tree *);
-static bool replace_def_variable (var_map, def_operand_p, tree *);
-static void eliminate_virtual_phis (void);
-static void coalesce_abnormal_edges (var_map, conflict_graph, root_var_p);
-static void print_exprs (FILE *, const char *, tree, const char *, tree,
- const char *);
-static void print_exprs_edge (FILE *, edge, const char *, tree, const char *,
- tree);
-
-
-/* Create a temporary variable based on the type of variable T. Use T's name
- as the prefix. */
-
-static tree
-create_temp (tree t)
+/* For an edge E find out a good source location to associate with
+ instructions inserted on edge E. If E has an implicit goto set,
+ 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. */
+
+static void
+set_location_for_edge (edge e)
{
- tree tmp;
- const char *name = NULL;
- tree type;
+ if (e->goto_locus)
+ {
+ set_curr_insn_source_location (e->goto_locus);
+ set_curr_insn_block (e->goto_block);
+ }
+ else
+ {
+ basic_block bb = e->src;
+ gimple_stmt_iterator gsi;
- if (TREE_CODE (t) == SSA_NAME)
- t = SSA_NAME_VAR (t);
-
- if (TREE_CODE (t) != VAR_DECL
- && TREE_CODE (t) != PARM_DECL)
- abort ();
-
- type = TREE_TYPE (t);
- tmp = DECL_NAME (t);
- if (tmp)
- name = IDENTIFIER_POINTER (tmp);
-
- if (name == NULL)
- name = "temp";
- tmp = create_tmp_var (type, name);
- DECL_ARTIFICIAL (tmp) = DECL_ARTIFICIAL (t);
- add_referenced_tmp_var (tmp);
-
- /* add_referenced_tmp_var will create the annotation and set up some
- of the flags in the annotation. However, some flags we need to
- inherit from our original variable. */
- var_ann (tmp)->type_mem_tag = var_ann (t)->type_mem_tag;
- if (is_call_clobbered (t))
- mark_call_clobbered (tmp);
-
- return tmp;
+ do
+ {
+ for (gsi = gsi_last_bb (bb); !gsi_end_p (gsi); gsi_prev (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ if (gimple_has_location (stmt) || gimple_block (stmt))
+ {
+ set_curr_insn_source_location (gimple_location (stmt));
+ set_curr_insn_block (gimple_block (stmt));
+ return;
+ }
+ }
+ /* Nothing found in this basic block. Make a half-assed attempt
+ to continue with another block. */
+ if (single_pred_p (bb))
+ bb = single_pred (bb);
+ else
+ bb = e->src;
+ }
+ while (bb != e->src);
+ }
+}
+
+/* Emit insns to copy SRC into DEST converting SRC if necessary. */
+
+static inline rtx
+emit_partition_copy (rtx dest, rtx src, int unsignedsrcp)
+{
+ rtx seq;
+
+ start_sequence ();
+
+ if (GET_MODE (src) != VOIDmode && GET_MODE (src) != GET_MODE (dest))
+ src = convert_to_mode (GET_MODE (dest), src, unsignedsrcp);
+ emit_move_insn (dest, src);
+
+ seq = get_insns ();
+ end_sequence ();
+
+ return seq;
+}
+
+/* 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)
+{
+ rtx seq;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file,
+ "Inserting a partition copy on edge BB%d->BB%d :"
+ "PART.%d = PART.%d",
+ e->src->index,
+ e->dest->index, dest, src);
+ fprintf (dump_file, "\n");
+ }
+
+ gcc_assert (SA.partition_to_pseudo[dest]);
+ gcc_assert (SA.partition_to_pseudo[src]);
+
+ set_location_for_edge (e);
+
+ seq = emit_partition_copy (SA.partition_to_pseudo[dest],
+ SA.partition_to_pseudo[src],
+ TYPE_UNSIGNED (TREE_TYPE (
+ partition_to_var (SA.map, src))));
+
+ insert_insn_on_edge (seq, e);
}
+/* Insert a copy instruction from expression SRC to partition DEST
+ onto edge E. */
+
+static void
+insert_value_copy_on_edge (edge e, int dest, tree src)
+{
+ rtx seq, x;
+ enum machine_mode mode;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file,
+ "Inserting a value copy on edge BB%d->BB%d : PART.%d = ",
+ e->src->index,
+ e->dest->index, dest);
+ print_generic_expr (dump_file, src, TDF_SLIM);
+ fprintf (dump_file, "\n");
+ }
+
+ gcc_assert (SA.partition_to_pseudo[dest]);
+
+ set_location_for_edge (e);
+
+ start_sequence ();
+ mode = GET_MODE (SA.partition_to_pseudo[dest]);
+ x = expand_expr (src, SA.partition_to_pseudo[dest], mode, EXPAND_NORMAL);
+ if (GET_MODE (x) != VOIDmode && GET_MODE (x) != mode)
+ x = convert_to_mode (mode, x, TYPE_UNSIGNED (TREE_TYPE (src)));
+ if (CONSTANT_P (x) && GET_MODE (x) == VOIDmode
+ && mode != TYPE_MODE (TREE_TYPE (src)))
+ x = convert_modes (mode, TYPE_MODE (TREE_TYPE (src)),
+ x, TYPE_UNSIGNED (TREE_TYPE (src)));
+ if (x != SA.partition_to_pseudo[dest])
+ emit_move_insn (SA.partition_to_pseudo[dest], x);
+ seq = get_insns ();
+ end_sequence ();
+
+ insert_insn_on_edge (seq, e);
+}
-/* This helper function fill insert a copy from a constant or variable SRC to
- variable DEST on edge E. */
+/* Insert a copy instruction from RTL expression SRC to partition DEST
+ onto edge E. */
static void
-insert_copy_on_edge (edge e, tree dest, tree src)
+insert_rtx_to_part_on_edge (edge e, int dest, rtx src, int unsignedsrcp)
{
- tree copy;
+ rtx seq;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file,
+ "Inserting a temp copy on edge BB%d->BB%d : PART.%d = ",
+ e->src->index,
+ e->dest->index, dest);
+ print_simple_rtl (dump_file, src);
+ fprintf (dump_file, "\n");
+ }
+
+ gcc_assert (SA.partition_to_pseudo[dest]);
+ set_location_for_edge (e);
+
+ seq = emit_partition_copy (SA.partition_to_pseudo[dest],
+ src,
+ unsignedsrcp);
- copy = build (MODIFY_EXPR, TREE_TYPE (dest), dest, src);
- set_is_used (dest);
+ insert_insn_on_edge (seq, e);
+}
- if (TREE_CODE (src) == ADDR_EXPR)
- src = TREE_OPERAND (src, 0);
- if (TREE_CODE (src) == VAR_DECL || TREE_CODE (src) == PARM_DECL)
- set_is_used (src);
+/* Insert a copy instruction from partition SRC to RTL lvalue DEST
+ onto edge E. */
+static void
+insert_part_to_rtx_on_edge (edge e, rtx dest, int src)
+{
+ rtx seq;
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file,
- "Inserting a copy on edge BB%d->BB%d :",
+ "Inserting a temp copy on edge BB%d->BB%d : ",
e->src->index,
e->dest->index);
- print_generic_expr (dump_file, copy, dump_flags);
- fprintf (dump_file, "\n");
+ print_simple_rtl (dump_file, dest);
+ fprintf (dump_file, "= PART.%d\n", src);
}
- bsi_insert_on_edge (e, copy);
+ gcc_assert (SA.partition_to_pseudo[src]);
+ set_location_for_edge (e);
+
+ seq = emit_partition_copy (dest,
+ SA.partition_to_pseudo[src],
+ TYPE_UNSIGNED (TREE_TYPE (
+ partition_to_var (SA.map, src))));
+
+ insert_insn_on_edge (seq, e);
}
{
elim_graph g = (elim_graph) xmalloc (sizeof (struct _elim_graph));
- VARRAY_TREE_INIT (g->nodes, 30, "Elimination Node List");
- VARRAY_TREE_INIT (g->const_copies, 20, "Elimination Constant Copies");
- VARRAY_INT_INIT (g->edge_list, 20, "Elimination Edge List");
- VARRAY_INT_INIT (g->stack, 30, " Elimination Stack");
+ g->nodes = VEC_alloc (int, heap, 30);
+ g->const_dests = VEC_alloc (int, heap, 20);
+ g->const_copies = VEC_alloc (tree, heap, 20);
+ g->edge_list = VEC_alloc (int, heap, 20);
+ g->stack = VEC_alloc (int, heap, 30);
g->visited = sbitmap_alloc (size);
static inline void
clear_elim_graph (elim_graph g)
{
- VARRAY_POP_ALL (g->nodes);
- VARRAY_POP_ALL (g->edge_list);
+ VEC_truncate (int, g->nodes, 0);
+ VEC_truncate (int, g->edge_list, 0);
}
delete_elim_graph (elim_graph g)
{
sbitmap_free (g->visited);
+ VEC_free (int, heap, g->stack);
+ VEC_free (int, heap, g->edge_list);
+ VEC_free (tree, heap, g->const_copies);
+ VEC_free (int, heap, g->const_dests);
+ VEC_free (int, heap, g->nodes);
free (g);
}
static inline int
elim_graph_size (elim_graph g)
{
- return VARRAY_ACTIVE_SIZE (g->nodes);
+ return VEC_length (int, g->nodes);
}
/* Add NODE to graph G, if it doesn't exist already. */
static inline void
-elim_graph_add_node (elim_graph g, tree node)
+elim_graph_add_node (elim_graph g, int node)
{
int x;
- for (x = 0; x < elim_graph_size (g); x++)
- if (VARRAY_TREE (g->nodes, x) == node)
+ int t;
+
+ for (x = 0; VEC_iterate (int, g->nodes, x, t); x++)
+ if (t == node)
return;
- VARRAY_PUSH_TREE (g->nodes, node);
+ VEC_safe_push (int, heap, g->nodes, node);
}
static inline void
elim_graph_add_edge (elim_graph g, int pred, int succ)
{
- VARRAY_PUSH_INT (g->edge_list, pred);
- VARRAY_PUSH_INT (g->edge_list, succ);
+ VEC_safe_push (int, heap, g->edge_list, pred);
+ VEC_safe_push (int, heap, g->edge_list, succ);
}
{
int y;
unsigned x;
- for (x = 0; x < VARRAY_ACTIVE_SIZE (g->edge_list); x += 2)
- if (VARRAY_INT (g->edge_list, x) == node)
+ for (x = 0; x < VEC_length (int, g->edge_list); x += 2)
+ if (VEC_index (int, g->edge_list, x) == node)
{
- VARRAY_INT (g->edge_list, x) = -1;
- y = VARRAY_INT (g->edge_list, x + 1);
- VARRAY_INT (g->edge_list, x + 1) = -1;
+ VEC_replace (int, g->edge_list, x, -1);
+ y = VEC_index (int, g->edge_list, x + 1);
+ VEC_replace (int, g->edge_list, x + 1, -1);
return y;
}
return -1;
do { \
unsigned x_; \
int y_; \
- for (x_ = 0; x_ < VARRAY_ACTIVE_SIZE ((GRAPH)->edge_list); x_ += 2) \
+ for (x_ = 0; x_ < VEC_length (int, (GRAPH)->edge_list); x_ += 2) \
{ \
- y_ = VARRAY_INT ((GRAPH)->edge_list, x_); \
+ y_ = VEC_index (int, (GRAPH)->edge_list, x_); \
if (y_ != (NODE)) \
continue; \
- (VAR) = VARRAY_INT ((GRAPH)->edge_list, x_ + 1); \
+ (VAR) = VEC_index (int, (GRAPH)->edge_list, x_ + 1); \
CODE; \
} \
} while (0)
do { \
unsigned x_; \
int y_; \
- for (x_ = 0; x_ < VARRAY_ACTIVE_SIZE ((GRAPH)->edge_list); x_ += 2) \
+ for (x_ = 0; x_ < VEC_length (int, (GRAPH)->edge_list); x_ += 2) \
{ \
- y_ = VARRAY_INT ((GRAPH)->edge_list, x_ + 1); \
+ y_ = VEC_index (int, (GRAPH)->edge_list, x_ + 1); \
if (y_ != (NODE)) \
continue; \
- (VAR) = VARRAY_INT ((GRAPH)->edge_list, x_); \
+ (VAR) = VEC_index (int, (GRAPH)->edge_list, x_); \
CODE; \
} \
} while (0)
/* Add T to elimination graph G. */
static inline void
-eliminate_name (elim_graph g, tree T)
+eliminate_name (elim_graph g, int T)
{
elim_graph_add_node (g, T);
}
-/* Build elimination graph G for basic block BB on incoming PHI edge I. */
+/* Build elimination graph G for basic block BB on incoming PHI edge
+ G->e. */
static void
-eliminate_build (elim_graph g, basic_block B, int i)
+eliminate_build (elim_graph g)
{
- tree phi;
- tree T0, Ti;
+ tree Ti;
int p0, pi;
+ gimple_stmt_iterator gsi;
clear_elim_graph (g);
- for (phi = phi_nodes (B); phi; phi = PHI_CHAIN (phi))
+ for (gsi = gsi_start_phis (g->e->dest); !gsi_end_p (gsi); gsi_next (&gsi))
{
- T0 = var_to_partition_to_var (g->map, PHI_RESULT (phi));
-
+ gimple phi = gsi_stmt (gsi);
+
+ p0 = var_to_partition (g->map, gimple_phi_result (phi));
/* Ignore results which are not in partitions. */
- if (T0 == NULL_TREE)
+ if (p0 == NO_PARTITION)
continue;
- if (PHI_ARG_EDGE (phi, i) == g->e)
- Ti = PHI_ARG_DEF (phi, i);
- else
- {
- /* On rare occasions, a PHI node may not have the arguments
- in the same order as all of the other PHI nodes. If they don't
- match, find the appropriate index here. */
- pi = phi_arg_from_edge (phi, g->e);
- if (pi == -1)
- abort();
- Ti = PHI_ARG_DEF (phi, pi);
- }
+ Ti = PHI_ARG_DEF (phi, g->e->dest_idx);
/* 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
{
/* Save constant copies until all other copies have been emitted
on this edge. */
- VARRAY_PUSH_TREE (g->const_copies, T0);
- VARRAY_PUSH_TREE (g->const_copies, Ti);
+ VEC_safe_push (int, heap, g->const_dests, p0);
+ VEC_safe_push (tree, heap, g->const_copies, Ti);
}
else
{
- Ti = var_to_partition_to_var (g->map, Ti);
- if (T0 != Ti)
+ pi = var_to_partition (g->map, Ti);
+ if (p0 != pi)
{
- eliminate_name (g, T0);
- eliminate_name (g, Ti);
- p0 = var_to_partition (g->map, T0);
- pi = var_to_partition (g->map, Ti);
+ eliminate_name (g, p0);
+ eliminate_name (g, pi);
elim_graph_add_edge (g, p0, pi);
}
}
if (!TEST_BIT (g->visited, S))
elim_forward (g, S);
});
- VARRAY_PUSH_INT (g->stack, T);
+ VEC_safe_push (int, heap, g->stack, T);
}
if (!TEST_BIT (g->visited, P))
{
elim_backward (g, P);
- insert_copy_on_edge (g->e,
- partition_to_var (g->map, P),
- partition_to_var (g->map, T));
+ insert_partition_copy_on_edge (g->e, P, T);
}
});
}
+/* Allocate a new pseudo register usable for storing values sitting
+ in NAME (a decl or SSA name), i.e. with matching mode and attributes. */
+
+static rtx
+get_temp_reg (tree name)
+{
+ tree var = TREE_CODE (name) == SSA_NAME ? SSA_NAME_VAR (name) : name;
+ tree type = TREE_TYPE (var);
+ int unsignedp = TYPE_UNSIGNED (type);
+ enum machine_mode reg_mode
+ = promote_mode (type, DECL_MODE (var), &unsignedp, 0);
+ rtx x = gen_reg_rtx (reg_mode);
+ if (POINTER_TYPE_P (type))
+ mark_reg_pointer (x, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (var))));
+ return x;
+}
+
/* Insert required copies for T in graph G. Check for a strongly connected
region, and create a temporary to break the cycle if one is found. */
static void
elim_create (elim_graph g, int T)
{
- tree U;
int P, S;
if (elim_unvisited_predecessor (g, T))
{
- U = create_temp (partition_to_var (g->map, T));
- insert_copy_on_edge (g->e, U, partition_to_var (g->map, T));
+ tree var = partition_to_var (g->map, T);
+ rtx U = get_temp_reg (var);
+ int unsignedsrcp = TYPE_UNSIGNED (TREE_TYPE (var));
+
+ insert_part_to_rtx_on_edge (g->e, U, T);
FOR_EACH_ELIM_GRAPH_PRED (g, T, P,
{
if (!TEST_BIT (g->visited, P))
{
elim_backward (g, P);
- insert_copy_on_edge (g->e, partition_to_var (g->map, P), U);
+ insert_rtx_to_part_on_edge (g->e, P, U, unsignedsrcp);
}
});
}
if (S != -1)
{
SET_BIT (g->visited, T);
- insert_copy_on_edge (g->e,
- partition_to_var (g->map, T),
- partition_to_var (g->map, S));
+ insert_partition_copy_on_edge (g->e, T, S);
}
}
-
}
-/* Eliminate all the phi nodes on edge E in graph G. I is the usual PHI
- index that edge E's values are found on. */
+
+/* Eliminate all the phi nodes on edge E in graph G. */
static void
-eliminate_phi (edge e, int i, elim_graph g)
+eliminate_phi (edge e, elim_graph g)
{
- int num_nodes = 0;
int x;
- basic_block B = e->dest;
-#if defined ENABLE_CHECKING
- if (i == -1)
- abort ();
- if (VARRAY_ACTIVE_SIZE (g->const_copies) != 0)
- abort ();
-#endif
+ gcc_assert (VEC_length (tree, g->const_copies) == 0);
- /* Abnormal edges already have everything coalesced, or the coalescer
- would have aborted. */
+ /* Abnormal edges already have everything coalesced. */
if (e->flags & EDGE_ABNORMAL)
return;
- num_nodes = num_var_partitions (g->map);
g->e = e;
- eliminate_build (g, B, i);
+ eliminate_build (g);
if (elim_graph_size (g) != 0)
{
+ int part;
+
sbitmap_zero (g->visited);
- VARRAY_POP_ALL (g->stack);
+ VEC_truncate (int, g->stack, 0);
- for (x = 0; x < elim_graph_size (g); x++)
+ for (x = 0; VEC_iterate (int, g->nodes, x, part); x++)
{
- tree var = VARRAY_TREE (g->nodes, x);
- int p = var_to_partition (g->map, var);
- if (!TEST_BIT (g->visited, p))
- elim_forward (g, p);
+ if (!TEST_BIT (g->visited, part))
+ elim_forward (g, part);
}
sbitmap_zero (g->visited);
- while (VARRAY_ACTIVE_SIZE (g->stack) > 0)
+ while (VEC_length (int, g->stack) > 0)
{
- x = VARRAY_TOP_INT (g->stack);
- VARRAY_POP (g->stack);
+ x = VEC_pop (int, g->stack);
if (!TEST_BIT (g->visited, x))
elim_create (g, x);
}
}
/* If there are any pending constant copies, issue them now. */
- while (VARRAY_ACTIVE_SIZE (g->const_copies) > 0)
+ while (VEC_length (tree, g->const_copies) > 0)
{
- tree src, dest;
- src = VARRAY_TOP_TREE (g->const_copies);
- VARRAY_POP (g->const_copies);
- dest = VARRAY_TOP_TREE (g->const_copies);
- VARRAY_POP (g->const_copies);
- insert_copy_on_edge (e, dest, src);
+ int dest;
+ tree src;
+ src = VEC_pop (tree, g->const_copies);
+ dest = VEC_pop (int, g->const_dests);
+ insert_value_copy_on_edge (e, dest, src);
}
}
-/* Shortcut routine to print messages to file F of the form:
- "STR1 EXPR1 STR2 EXPR2 STR3." */
+/* Remove each argument from PHI. If an arg was the last use of an SSA_NAME,
+ check to see if this allows another PHI node to be removed. */
static void
-print_exprs (FILE *f, const char *str1, tree expr1, const char *str2,
- tree expr2, const char *str3)
+remove_gimple_phi_args (gimple phi)
{
- fprintf (f, "%s", str1);
- print_generic_expr (f, expr1, TDF_SLIM);
- fprintf (f, "%s", str2);
- print_generic_expr (f, expr2, TDF_SLIM);
- fprintf (f, "%s", str3);
-}
-
-
-/* Shortcut routine to print abnormal edge messages to file F of the form:
- "STR1 EXPR1 STR2 EXPR2 across edge E. */
-
-static void
-print_exprs_edge (FILE *f, edge e, const char *str1, tree expr1,
- const char *str2, tree expr2)
-{
- print_exprs (f, str1, expr1, str2, expr2, " across an abnormal edge");
- fprintf (f, " from BB%d->BB%d\n", e->src->index,
- e->dest->index);
-}
-
-
-/* Coalesce partitions in MAP which are live across abnormal edges in GRAPH.
- RV is the root variable groupings of the partitions in MAP. Since code
- cannot be inserted on these edges, failure to coalesce something across
- an abnormal edge is an error. */
-
-static void
-coalesce_abnormal_edges (var_map map, conflict_graph graph, root_var_p rv)
-{
- basic_block bb;
- edge e;
- tree phi, var, tmp;
- int x, y;
-
- /* Code cannot be inserted on abnormal edges. Look for all abnormal
- edges, and coalesce any PHI results with their arguments across
- that edge. */
+ use_operand_p arg_p;
+ ssa_op_iter iter;
- FOR_EACH_BB (bb)
- for (e = bb->succ; e; e = e->succ_next)
- if (e->dest != EXIT_BLOCK_PTR && e->flags & EDGE_ABNORMAL)
- for (phi = phi_nodes (e->dest); phi; phi = PHI_CHAIN (phi))
- {
- /* Visit each PHI on the destination side of this abnormal
- edge, and attempt to coalesce the argument with the result. */
- var = PHI_RESULT (phi);
- x = var_to_partition (map, var);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Removing Dead PHI definition: ");
+ print_gimple_stmt (dump_file, phi, 0, TDF_SLIM);
+ }
- /* Ignore results which are not relevant. */
- if (x == NO_PARTITION)
- continue;
+ FOR_EACH_PHI_ARG (arg_p, phi, iter, SSA_OP_USE)
+ {
+ tree arg = USE_FROM_PTR (arg_p);
+ if (TREE_CODE (arg) == SSA_NAME)
+ {
+ /* Remove the reference to the existing argument. */
+ SET_USE (arg_p, NULL_TREE);
+ if (has_zero_uses (arg))
+ {
+ gimple stmt;
+ gimple_stmt_iterator gsi;
- y = phi_arg_from_edge (phi, e);
- if (y == -1)
- abort ();
+ stmt = SSA_NAME_DEF_STMT (arg);
- tmp = PHI_ARG_DEF (phi, y);
- if (!phi_ssa_name_p (tmp))
- {
- print_exprs_edge (stderr, e,
- "\nConstant argument in PHI. Can't insert :",
- var, " = ", tmp);
- abort ();
- }
- y = var_to_partition (map, tmp);
- if (x == NO_PARTITION || y == NO_PARTITION)
- abort ();
- if (root_var_find (rv, x) != root_var_find (rv, y))
- {
- print_exprs_edge (stderr, e, "\nDifferent root vars: ",
- root_var (rv, root_var_find (rv, x)),
- " and ",
- root_var (rv, root_var_find (rv, y)));
- abort ();
- }
+ /* Also remove the def if it is a PHI node. */
+ if (gimple_code (stmt) == GIMPLE_PHI)
+ {
+ remove_gimple_phi_args (stmt);
+ gsi = gsi_for_stmt (stmt);
+ remove_phi_node (&gsi, true);
+ }
- if (x != y)
- {
- if (!conflict_graph_conflict_p (graph, x, y))
- {
- /* Now map the partitions back to their real variables. */
- var = partition_to_var (map, x);
- tmp = partition_to_var (map, y);
- if (dump_file
- && (dump_flags & TDF_DETAILS))
- {
- print_exprs_edge (dump_file, e,
- "ABNORMAL: Coalescing ",
- var, " and ", tmp);
- }
- if (var_union (map, var, tmp) == NO_PARTITION)
- {
- print_exprs_edge (stderr, e, "\nUnable to coalesce",
- partition_to_var (map, x), " and ",
- partition_to_var (map, y));
- abort ();
- }
- conflict_graph_merge_regs (graph, x, y);
- }
- else
- {
- print_exprs_edge (stderr, e, "\n Conflict ",
- partition_to_var (map, x),
- " and ", partition_to_var (map, y));
- abort ();
- }
- }
- }
+ }
+ }
+ }
}
+/* Remove any PHI node which is a virtual PHI, or a PHI with no uses. */
-/* Reduce the number of live ranges in MAP. Live range information is
- returned if FLAGS indicates that we are combining temporaries, otherwise
- NULL is returned. The only partitions which are associated with actual
- variables at this point are those which are forced to be coalesced for
- various reason. (live on entry, live across abnormal edges, etc.). */
-
-static tree_live_info_p
-coalesce_ssa_name (var_map map, int flags)
+static void
+eliminate_useless_phis (void)
{
- int num, x, i;
- sbitmap live;
- tree var, phi;
- root_var_p rv;
- tree_live_info_p liveinfo;
- var_ann_t ann;
- conflict_graph graph;
basic_block bb;
- coalesce_list_p cl = NULL;
-
- if (num_var_partitions (map) <= 1)
- return NULL;
-
- /* If no preference given, use cheap coalescing of all partitions. */
- if ((flags & (SSANORM_COALESCE_PARTITIONS | SSANORM_USE_COALESCE_LIST)) == 0)
- flags |= SSANORM_COALESCE_PARTITIONS;
-
- liveinfo = calculate_live_on_entry (map);
- calculate_live_on_exit (liveinfo);
- rv = root_var_init (map);
-
- /* Remove single element variable from the list. */
- root_var_compact (rv);
+ gimple_stmt_iterator gsi;
+ tree result;
- if (flags & SSANORM_USE_COALESCE_LIST)
+ FOR_EACH_BB (bb)
{
- cl = create_coalesce_list (map);
-
- /* Add all potential copies via PHI arguments to the list. */
- FOR_EACH_BB (bb)
- {
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
+ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); )
+ {
+ gimple phi = gsi_stmt (gsi);
+ result = gimple_phi_result (phi);
+ if (!is_gimple_reg (SSA_NAME_VAR (result)))
{
- tree res = PHI_RESULT (phi);
- int p = var_to_partition (map, res);
- if (p == NO_PARTITION)
- continue;
- for (x = 0; x < PHI_NUM_ARGS (phi); x++)
- {
- tree arg = PHI_ARG_DEF (phi, x);
- int p2;
-
- if (TREE_CODE (arg) != SSA_NAME)
- continue;
- if (SSA_NAME_VAR (res) != SSA_NAME_VAR (arg))
- continue;
- p2 = var_to_partition (map, PHI_ARG_DEF (phi, x));
- if (p2 != NO_PARTITION)
- add_coalesce (cl, p, p2, 1);
+#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
+ && is_gimple_reg (SSA_NAME_VAR (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
+ remove_phi_node (&gsi, true);
}
- }
-
- /* Coalesce all the result decls together. */
- var = NULL_TREE;
- i = 0;
- for (x = 0; x < num_var_partitions (map); x++)
- {
- tree p = partition_to_var (map, x);
- if (TREE_CODE (SSA_NAME_VAR(p)) == RESULT_DECL)
+ else
{
- if (var == NULL_TREE)
- {
- var = p;
- i = x;
+ /* Also remove real PHIs with no uses. */
+ if (has_zero_uses (result))
+ {
+ remove_gimple_phi_args (phi);
+ remove_phi_node (&gsi, true);
}
else
- add_coalesce (cl, i, x, 1);
+ gsi_next (&gsi);
}
}
}
+}
- /* Build a conflict graph. */
- graph = build_tree_conflict_graph (liveinfo, rv, cl);
-
- if (cl)
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Before sorting:\n");
- dump_coalesce_list (dump_file, cl);
- }
-
- sort_coalesce_list (cl);
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "\nAfter sorting:\n");
- dump_coalesce_list (dump_file, cl);
- }
- }
-
- /* Put the single element variables back in. */
- root_var_decompact (rv);
-
- /* First, coalesce all live on entry variables to their root variable.
- This will ensure the first use is coming from the correct location. */
-
- live = sbitmap_alloc (num_var_partitions (map));
- sbitmap_zero (live);
-
- /* Set 'live' vector to indicate live on entry partitions. */
- num = num_var_partitions (map);
- for (x = 0 ; x < num; x++)
- {
- var = partition_to_var (map, x);
- if (default_def (SSA_NAME_VAR (var)) == var)
- SET_BIT (live, x);
- }
- if ((flags & SSANORM_COMBINE_TEMPS) == 0)
- {
- delete_tree_live_info (liveinfo);
- liveinfo = NULL;
- }
+/* This function will rewrite the current program using the variable mapping
+ found in MAP. If the replacement vector VALUES is provided, any
+ occurrences of partitions with non-null entries in the vector will be
+ replaced with the expression in the vector instead of its mapped
+ variable. */
- /* Assign root variable as partition representative for each live on entry
- partition. */
- EXECUTE_IF_SET_IN_SBITMAP (live, 0, x,
+static void
+rewrite_trees (var_map map ATTRIBUTE_UNUSED)
+{
+#ifdef ENABLE_CHECKING
+ 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)
{
- var = root_var (rv, root_var_find (rv, x));
- ann = var_ann (var);
- /* If these aren't already coalesced... */
- if (partition_to_var (map, x) != var)
+ gimple_stmt_iterator gsi;
+ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
- if (ann->out_of_ssa_tag)
+ gimple phi = gsi_stmt (gsi);
+ tree T0 = var_to_partition_to_var (map, gimple_phi_result (phi));
+ if (T0 == NULL_TREE)
{
- /* This root variable has already been assigned to another
- partition which is not coalesced with this one. */
- abort ();
- }
+ size_t i;
+ for (i = 0; i < gimple_phi_num_args (phi); i++)
+ {
+ tree arg = PHI_ARG_DEF (phi, i);
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- print_exprs (dump_file, "Must coalesce ",
- partition_to_var (map, x),
- " with the root variable ", var, ".\n");
+ if (TREE_CODE (arg) == SSA_NAME
+ && var_to_partition (map, arg) != NO_PARTITION)
+ {
+ fprintf (stderr, "Argument of PHI is in a partition :(");
+ print_generic_expr (stderr, arg, TDF_SLIM);
+ fprintf (stderr, "), but the result is not :");
+ print_gimple_stmt (stderr, phi, 0, TDF_SLIM);
+ internal_error ("SSA corruption");
+ }
+ }
}
-
- change_partition_var (map, var, x);
}
- });
-
- sbitmap_free (live);
+ }
+#endif
+}
- /* Coalesce partitions live across abnormal edges. */
- coalesce_abnormal_edges (map, graph, rv);
+/* 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
+ some RTL instructions inserted on edges. */
- if (dump_file && (dump_flags & TDF_DETAILS))
- dump_var_map (dump_file, map);
+void
+expand_phi_nodes (struct ssaexpand *sa)
+{
+ basic_block bb;
+ elim_graph g = new_elim_graph (sa->map->num_partitions);
+ g->map = sa->map;
- /* Coalesce partitions. */
- if (flags & SSANORM_USE_COALESCE_LIST)
- coalesce_tpa_members (rv, graph, map, cl,
- ((dump_flags & TDF_DETAILS) ? dump_file
- : NULL));
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR, 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);
+ 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,
+ which it is only for critical edges, normally. For EH edges
+ it might also be necessary when the successor has more than
+ one predecessor. In that case the edge is either required to
+ be fallthru (which EH edges aren't), or the predecessor needs
+ to end with a jump (which again, isn't the case with EH edges).
+ Hence, split all EH edges on which we inserted instructions
+ and whose successor has multiple predecessors. */
+ for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); )
+ {
+ if (e->insns.r && (e->flags & EDGE_EH)
+ && !single_pred_p (e->dest))
+ {
+ rtx insns = e->insns.r;
+ basic_block bb;
+ e->insns.r = NULL_RTX;
+ bb = split_edge (e);
+ single_pred_edge (bb)->insns.r = insns;
+ }
+ else
+ ei_next (&ei);
+ }
+ }
-
- if (flags & SSANORM_COALESCE_PARTITIONS)
- coalesce_tpa_members (rv, graph, map, NULL,
- ((dump_flags & TDF_DETAILS) ? dump_file
- : NULL));
- if (cl)
- delete_coalesce_list (cl);
- root_var_delete (rv);
- conflict_graph_delete (graph);
-
- return liveinfo;
+ delete_elim_graph (g);
}
-/* Take the ssa-name var_map MAP, and assign real variables to each
- partition. */
+/* Remove the ssa-names in the current function and translate them into normal
+ compiler variables. PERFORM_TER is true if Temporary Expression Replacement
+ should also be used. */
static void
-assign_vars (var_map map)
+remove_ssa_form (bool perform_ter, struct ssaexpand *sa)
{
- int x, i, num, rep;
- tree t, var;
- var_ann_t ann;
- root_var_p rv;
+ bitmap values = NULL;
+ var_map map;
+ unsigned i;
- rv = root_var_init (map);
- if (!rv)
- return;
+ map = coalesce_ssa_name ();
- /* Coalescing may already have forced some partitions to their root
- variable. Find these and tag them. */
+ /* Return to viewing the variable list as just all reference variables after
+ coalescing has been performed. */
+ partition_view_normal (map, false);
- num = num_var_partitions (map);
- for (x = 0; x < num; x++)
+ if (dump_file && (dump_flags & TDF_DETAILS))
{
- var = partition_to_var (map, x);
- if (TREE_CODE (var) != SSA_NAME)
- {
- /* Coalescing will already have verified that more than one
- partition doesn't have the same root variable. Simply marked
- the variable as assigned. */
- ann = var_ann (var);
- ann->out_of_ssa_tag = 1;
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "partition %d has variable ", x);
- print_generic_expr (dump_file, var, TDF_SLIM);
- fprintf (dump_file, " assigned to it.\n");
- }
-
- }
+ fprintf (dump_file, "After Coalescing:\n");
+ dump_var_map (dump_file, map);
}
- num = root_var_num (rv);
- for (x = 0; x < num; x++)
+ if (perform_ter)
{
- var = root_var (rv, x);
- ann = var_ann (var);
- for (i = root_var_first_partition (rv, x);
- i != ROOT_VAR_NONE;
- i = root_var_next_partition (rv, i))
- {
- t = partition_to_var (map, i);
-
- if (t == var || TREE_CODE (t) != SSA_NAME)
- continue;
-
- rep = var_to_partition (map, t);
-
- if (!ann->out_of_ssa_tag)
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- print_exprs (dump_file, "", t, " --> ", var, "\n");
- change_partition_var (map, var, rep);
- continue;
- }
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- print_exprs (dump_file, "", t, " not coalesced with ", var,
- "");
+ values = find_replaceable_exprs (map);
+ if (values && dump_file && (dump_flags & TDF_DETAILS))
+ dump_replaceable_exprs (dump_file, values);
+ }
- var = create_temp (t);
- change_partition_var (map, var, rep);
- ann = var_ann (var);
+ rewrite_trees (map);
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, " --> New temp: '");
- print_generic_expr (dump_file, var, TDF_SLIM);
- fprintf (dump_file, "'\n");
- }
+ 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);
}
}
-
- root_var_delete (rv);
}
-/* Replace use operand P with whatever variable it has been rewritten to based
- on the partitions in MAP. EXPR is an optional expression vector over SSA
- versions which is used to replace P with an expression instead of a variable.
- If the stmt is changed, return true. */
+/* If not already done so for basic block BB, assign increasing uids
+ to each of its instructions. */
-static inline bool
-replace_use_variable (var_map map, use_operand_p p, tree *expr)
+static void
+maybe_renumber_stmts_bb (basic_block bb)
{
- tree new_var;
- tree var = USE_FROM_PTR (p);
-
- /* Check if we are replacing this variable with an expression. */
- if (expr)
- {
- int version = SSA_NAME_VERSION (var);
- if (expr[version])
- {
- tree new_expr = TREE_OPERAND (expr[version], 1);
- SET_USE (p, new_expr);
- /* Clear the stmt's RHS, or GC might bite us. */
- TREE_OPERAND (expr[version], 1) = NULL_TREE;
- return true;
- }
- }
-
- new_var = var_to_partition_to_var (map, var);
- if (new_var)
+ unsigned i = 0;
+ gimple_stmt_iterator gsi;
+
+ if (!bb->aux)
+ return;
+ bb->aux = NULL;
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
- SET_USE (p, new_var);
- set_is_used (new_var);
- return true;
+ gimple stmt = gsi_stmt (gsi);
+ gimple_set_uid (stmt, i);
+ i++;
}
- return false;
}
-/* Replace def operand DEF_P with whatever variable it has been rewritten to
- based on the partitions in MAP. EXPR is an optional expression vector over
- SSA versions which is used to replace DEF_P with an expression instead of a
- variable. If the stmt is changed, return true. */
+/* Return true if we can determine that the SSA_NAMEs RESULT (a result
+ of a PHI node) and ARG (one of its arguments) conflict. Return false
+ otherwise, also when we simply aren't sure. */
-static inline bool
-replace_def_variable (var_map map, def_operand_p def_p, tree *expr)
+static bool
+trivially_conflicts_p (basic_block bb, tree result, tree arg)
{
- tree new_var;
- tree var = DEF_FROM_PTR (def_p);
+ use_operand_p use;
+ imm_use_iterator imm_iter;
+ gimple defa = SSA_NAME_DEF_STMT (arg);
- /* Check if we are replacing this variable with an expression. */
- if (expr)
- {
- int version = SSA_NAME_VERSION (var);
- if (expr[version])
- {
- tree new_expr = TREE_OPERAND (expr[version], 1);
- SET_DEF (def_p, new_expr);
- /* Clear the stmt's RHS, or GC might bite us. */
- TREE_OPERAND (expr[version], 1) = NULL_TREE;
- return true;
- }
- }
+ /* If ARG isn't defined in the same block it's too complicated for
+ our little mind. */
+ if (gimple_bb (defa) != bb)
+ return false;
- new_var = var_to_partition_to_var (map, var);
- if (new_var)
+ FOR_EACH_IMM_USE_FAST (use, imm_iter, result)
{
- SET_DEF (def_p, new_var);
- set_is_used (new_var);
- return true;
+ gimple use_stmt = USE_STMT (use);
+ /* Now, if there's a use of RESULT that lies outside this basic block,
+ then there surely is a conflict with ARG. */
+ if (gimple_bb (use_stmt) != bb)
+ return true;
+ if (gimple_code (use_stmt) == GIMPLE_PHI)
+ continue;
+ /* The use now is in a real stmt of BB, so if ARG was defined
+ in a PHI node (like RESULT) both conflict. */
+ if (gimple_code (defa) == GIMPLE_PHI)
+ return true;
+ maybe_renumber_stmts_bb (bb);
+ /* If the use of RESULT occurs after the definition of ARG,
+ the two conflict too. */
+ if (gimple_uid (defa) < gimple_uid (use_stmt))
+ return true;
}
+
return false;
}
-/* Remove any PHI node which is a virtual PHI. */
+/* Search every PHI node for arguments associated with backedges which
+ we can trivially determine will need a copy (the argument is either
+ not an SSA_NAME or the argument has a different underlying variable
+ than the PHI result).
+
+ Insert a copy from the PHI argument to a new destination at the
+ end of the block with the backedge to the top of the loop. Update
+ the PHI argument to reference this new destination. */
static void
-eliminate_virtual_phis (void)
+insert_backedge_copies (void)
{
basic_block bb;
- tree phi, next;
+ gimple_stmt_iterator gsi;
FOR_EACH_BB (bb)
{
- for (phi = phi_nodes (bb); phi; phi = next)
- {
- next = PHI_CHAIN (phi);
- if (!is_gimple_reg (SSA_NAME_VAR (PHI_RESULT (phi))))
+ /* 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);
+ tree result = gimple_phi_result (phi);
+ tree result_var;
+ size_t i;
+
+ if (!is_gimple_reg (result))
+ continue;
+
+ result_var = SSA_NAME_VAR (result);
+ for (i = 0; i < gimple_phi_num_args (phi); i++)
{
-#ifdef ENABLE_CHECKING
- int i;
- /* There should be no arguments of this PHI which are in
- the partition list, or we get incorrect results. */
- for (i = 0; i < PHI_NUM_ARGS (phi); i++)
- {
- tree arg = PHI_ARG_DEF (phi, i);
- if (TREE_CODE (arg) == SSA_NAME
- && is_gimple_reg (SSA_NAME_VAR (arg)))
- {
- fprintf (stderr, "Argument of PHI is not virtual (");
- print_generic_expr (stderr, arg, TDF_SLIM);
- fprintf (stderr, "), but the result is :");
- print_generic_stmt (stderr, phi, TDF_SLIM);
- abort();
- }
- }
-#endif
- remove_phi_node (phi, NULL_TREE, bb);
- }
- }
- }
-}
-
-
-/* This routine will coalesce variables in MAP of the same type which do not
- interfere with each other. LIVEINFO is the live range info for variables
- of interest. This will both reduce the memory footprint of the stack, and
- allow us to coalesce together local copies of globals and scalarized
- component refs. */
-
-static void
-coalesce_vars (var_map map, tree_live_info_p liveinfo)
-{
- basic_block bb;
- type_var_p tv;
- tree var;
- int x, p, p2;
- coalesce_list_p cl;
- conflict_graph graph;
-
- cl = create_coalesce_list (map);
-
- /* Merge all the live on entry vectors for coalesced partitions. */
- for (x = 0; x < num_var_partitions (map); x++)
- {
- var = partition_to_var (map, x);
- p = var_to_partition (map, var);
- if (p != x)
- live_merge_and_clear (liveinfo, p, x);
- }
-
- /* When PHI nodes are turned into copies, the result of each PHI node
- becomes live on entry to the block. Mark these now. */
- FOR_EACH_BB (bb)
- {
- tree phi, arg;
- int p;
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
- {
- p = var_to_partition (map, PHI_RESULT (phi));
-
- /* Skip virtual PHI nodes. */
- if (p == NO_PARTITION)
- continue;
-
- make_live_on_entry (liveinfo, bb, p);
-
- /* Each argument is a potential copy operation. Add any arguments
- which are not coalesced to the result to the coalesce list. */
- for (x = 0; x < PHI_NUM_ARGS (phi); x++)
- {
- arg = PHI_ARG_DEF (phi, x);
- if (!phi_ssa_name_p (arg))
- continue;
- p2 = var_to_partition (map, arg);
- if (p2 == NO_PARTITION)
- continue;
- if (p != p2)
- add_coalesce (cl, p, p2, 1);
- }
- }
- }
-
-
- /* Re-calculate live on exit info. */
- calculate_live_on_exit (liveinfo);
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Live range info for variable memory coalescing.\n");
- dump_live_info (dump_file, liveinfo, LIVEDUMP_ALL);
-
- fprintf (dump_file, "Coalesce list from phi nodes:\n");
- dump_coalesce_list (dump_file, cl);
- }
-
-
- tv = type_var_init (map);
- if (dump_file)
- type_var_dump (dump_file, tv);
- type_var_compact (tv);
- if (dump_file)
- type_var_dump (dump_file, tv);
-
- graph = build_tree_conflict_graph (liveinfo, tv, cl);
-
- type_var_decompact (tv);
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "type var list now looks like:n");
- type_var_dump (dump_file, tv);
-
- fprintf (dump_file, "Coalesce list after conflict graph build:\n");
- dump_coalesce_list (dump_file, cl);
- }
-
- sort_coalesce_list (cl);
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Coalesce list after sorting:\n");
- dump_coalesce_list (dump_file, cl);
- }
-
- coalesce_tpa_members (tv, graph, map, cl,
- ((dump_flags & TDF_DETAILS) ? dump_file : NULL));
-
- type_var_delete (tv);
- delete_coalesce_list (cl);
-}
-
-
-/* Temporary Expression Replacement (TER)
-
- Replace SSA version variables during out-of-ssa with their defining
- expression if there is only one use of the variable.
-
- A pass is made through the function, one block at a time. No cross block
- information is tracked.
-
- Variables which only have one use, and whose defining stmt is considered
- a replaceable expression (see check_replaceable) are entered into
- consideration by adding a list of dependent partitions to the version_info
- vector for that ssa_name_version. This information comes from the partition
- mapping for each USE. At the same time, the partition_dep_list vector for
- these partitions have this version number entered into their lists.
-
- When the use of a replaceable ssa_variable is encountered, the dependence
- list in version_info[] is moved to the "pending_dependence" list in case
- the current expression is also replaceable. (To be determined later in
- processing this stmt.) version_info[] for the version is then updated to
- point to the defining stmt and the 'replaceable' bit is set.
-
- Any partition which is defined by a statement 'kills' any expression which
- is dependent on this partition. Every ssa version in the partitions'
- dependence list is removed from future consideration.
-
- All virtual references are lumped together. Any expression which is
- dependent on any virtual variable (via a VUSE) has a dependence added
- to the special partition defined by VIRTUAL_PARTITION.
-
- Whenever a V_MAY_DEF is seen, all expressions dependent this
- VIRTUAL_PARTITION are removed from consideration.
-
- At the end of a basic block, all expression are removed from consideration
- in preparation for the next block.
-
- The end result is a vector over SSA_NAME_VERSION which is passed back to
- rewrite_out_of_ssa. As the SSA variables are being rewritten, instead of
- replacing the SSA_NAME tree element with the partition it was assigned,
- it is replaced with the RHS of the defining expression. */
-
-
-/* Dependency list element. This can contain either a partition index or a
- version number, depending on which list it is in. */
-
-typedef struct value_expr_d
-{
- int value;
- struct value_expr_d *next;
-} *value_expr_p;
-
-
-/* Temporary Expression Replacement (TER) table information. */
-
-typedef struct temp_expr_table_d
-{
- var_map map;
- void **version_info;
- value_expr_p *partition_dep_list;
- bitmap replaceable;
- bool saw_replaceable;
- int virtual_partition;
- bitmap partition_in_use;
- value_expr_p free_list;
- value_expr_p pending_dependence;
-} *temp_expr_table_p;
-
-/* Used to indicate a dependency on V_MAY_DEFs. */
-#define VIRTUAL_PARTITION(table) (table->virtual_partition)
-
-static temp_expr_table_p new_temp_expr_table (var_map);
-static tree *free_temp_expr_table (temp_expr_table_p);
-static inline value_expr_p new_value_expr (temp_expr_table_p);
-static inline void free_value_expr (temp_expr_table_p, value_expr_p);
-static inline value_expr_p find_value_in_list (value_expr_p, int,
- value_expr_p *);
-static inline void add_value_to_list (temp_expr_table_p, value_expr_p *, int);
-static inline void add_info_to_list (temp_expr_table_p, value_expr_p *,
- value_expr_p);
-static value_expr_p remove_value_from_list (value_expr_p *, int);
-static void add_dependance (temp_expr_table_p, int, tree);
-static bool check_replaceable (temp_expr_table_p, tree);
-static void finish_expr (temp_expr_table_p, int, bool);
-static void mark_replaceable (temp_expr_table_p, tree);
-static inline void kill_expr (temp_expr_table_p, int, bool);
-static inline void kill_virtual_exprs (temp_expr_table_p, bool);
-static void find_replaceable_in_bb (temp_expr_table_p, basic_block);
-static tree *find_replaceable_exprs (var_map);
-static void dump_replaceable_exprs (FILE *, tree *);
-
-
-/* Create a new TER table for MAP. */
-
-static temp_expr_table_p
-new_temp_expr_table (var_map map)
-{
- temp_expr_table_p t;
-
- t = (temp_expr_table_p) xmalloc (sizeof (struct temp_expr_table_d));
- t->map = map;
-
- t->version_info = xcalloc (num_ssa_names + 1, sizeof (void *));
- t->partition_dep_list = xcalloc (num_var_partitions (map) + 1,
- sizeof (value_expr_p));
-
- t->replaceable = BITMAP_XMALLOC ();
- t->partition_in_use = BITMAP_XMALLOC ();
-
- t->saw_replaceable = false;
- t->virtual_partition = num_var_partitions (map);
- t->free_list = NULL;
- t->pending_dependence = NULL;
-
- return t;
-}
-
-
-/* Free TER table T. If there are valid replacements, return the expression
- vector. */
-
-static tree *
-free_temp_expr_table (temp_expr_table_p t)
-{
- value_expr_p p;
- tree *ret = NULL;
-
-#ifdef ENABLE_CHECKING
- int x;
- for (x = 0; x <= num_var_partitions (t->map); x++)
- if (t->partition_dep_list[x] != NULL)
- abort();
-#endif
-
- while ((p = t->free_list))
- {
- t->free_list = p->next;
- free (p);
- }
-
- BITMAP_XFREE (t->partition_in_use);
- BITMAP_XFREE (t->replaceable);
-
- free (t->partition_dep_list);
- if (t->saw_replaceable)
- ret = (tree *)t->version_info;
- else
- free (t->version_info);
-
- free (t);
- return ret;
-}
-
-
-/* Allocate a new value list node. Take it from the free list in TABLE if
- possible. */
-
-static inline value_expr_p
-new_value_expr (temp_expr_table_p table)
-{
- value_expr_p p;
- if (table->free_list)
- {
- p = table->free_list;
- table->free_list = p->next;
- }
- else
- p = (value_expr_p) xmalloc (sizeof (struct value_expr_d));
-
- return p;
-}
-
-
-/* Add value list node P to the free list in TABLE. */
-
-static inline void
-free_value_expr (temp_expr_table_p table, value_expr_p p)
-{
- p->next = table->free_list;
- table->free_list = p;
-}
-
-
-/* Find VALUE if its in LIST. Return a pointer to the list object if found,
- else return NULL. If LAST_PTR is provided, it will point to the previous
- item upon return, or NULL if this is the first item in the list. */
-
-static inline value_expr_p
-find_value_in_list (value_expr_p list, int value, value_expr_p *last_ptr)
-{
- value_expr_p curr;
- value_expr_p last = NULL;
-
- for (curr = list; curr; last = curr, curr = curr->next)
- {
- if (curr->value == value)
- break;
- }
- if (last_ptr)
- *last_ptr = last;
- return curr;
-}
-
-
-/* Add VALUE to LIST, if it isn't already present. TAB is the expression
- table */
-
-static inline void
-add_value_to_list (temp_expr_table_p tab, value_expr_p *list, int value)
-{
- value_expr_p info;
-
- if (!find_value_in_list (*list, value, NULL))
- {
- info = new_value_expr (tab);
- info->value = value;
- info->next = *list;
- *list = info;
- }
-}
-
-
-/* Add value node INFO if it's value isn't already in LIST. Free INFO if
- it is already in the list. TAB is the expression table. */
-
-static inline void
-add_info_to_list (temp_expr_table_p tab, value_expr_p *list, value_expr_p info)
-{
- if (find_value_in_list (*list, info->value, NULL))
- free_value_expr (tab, info);
- else
- {
- info->next = *list;
- *list = info;
- }
-}
-
-
-/* Look for VALUE in LIST. If found, remove it from the list and return it's
- pointer. */
-
-static value_expr_p
-remove_value_from_list (value_expr_p *list, int value)
-{
- value_expr_p info, last;
-
- info = find_value_in_list (*list, value, &last);
- if (!info)
- return NULL;
- if (!last)
- *list = info->next;
- else
- last->next = info->next;
-
- return info;
-}
-
-
-/* Add a dependency between the def of ssa VERSION and VAR. If VAR is
- replaceable by an expression, add a dependence each of the elements of the
- expression. These are contained in the pending list. TAB is the
- expression table. */
-
-static void
-add_dependance (temp_expr_table_p tab, int version, tree var)
-{
- int i, x;
- value_expr_p info;
-
- i = SSA_NAME_VERSION (var);
- if (bitmap_bit_p (tab->replaceable, i))
- {
- /* This variable is being substituted, so use whatever dependences
- were queued up when we marked this as replaceable earlier. */
- while ((info = tab->pending_dependence))
- {
- tab->pending_dependence = info->next;
- /* Get the partition this variable was dependent on. Reuse this
- object to represent the current expression instead. */
- x = info->value;
- info->value = version;
- add_info_to_list (tab, &(tab->partition_dep_list[x]), info);
- add_value_to_list (tab,
- (value_expr_p *)&(tab->version_info[version]), x);
- bitmap_set_bit (tab->partition_in_use, x);
- }
- }
- else
- {
- i = var_to_partition (tab->map, var);
-#ifdef ENABLE_CHECKING
- if (i== NO_PARTITION)
- abort ();
-#endif
- add_value_to_list (tab, &(tab->partition_dep_list[i]), version);
- add_value_to_list (tab,
- (value_expr_p *)&(tab->version_info[version]), i);
- bitmap_set_bit (tab->partition_in_use, i);
- }
-}
-
-
-/* Check if expression STMT is suitable for replacement in table TAB. If so,
- create an expression entry. Return true if this stmt is replaceable. */
-
-static bool
-check_replaceable (temp_expr_table_p tab, tree stmt)
-{
- stmt_ann_t ann;
- vuse_optype vuseops;
- def_optype defs;
- use_optype uses;
- tree var, def;
- int num_use_ops, version, i;
- var_map map = tab->map;
-
- if (TREE_CODE (stmt) != MODIFY_EXPR)
- return false;
-
- ann = stmt_ann (stmt);
- defs = DEF_OPS (ann);
-
- /* Punt if there is more than 1 def, or more than 1 use. */
- if (NUM_DEFS (defs) != 1)
- return false;
- def = DEF_OP (defs, 0);
- if (version_ref_count (map, def) != 1)
- return false;
-
- /* Assignments to variables assigned to hard registers are not
- replaceable. */
- if (DECL_HARD_REGISTER (SSA_NAME_VAR (def)))
- return false;
-
- /* There must be no V_MAY_DEFS. */
- if (NUM_V_MAY_DEFS (V_MAY_DEF_OPS (ann)) != 0)
- return false;
-
- /* There must be no V_MUST_DEFS. */
- if (NUM_V_MUST_DEFS (V_MUST_DEF_OPS (ann)) != 0)
- return false;
-
- /* Float expressions must go through memory if float-store is on. */
- if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (stmt, 1))))
- return false;
-
- uses = USE_OPS (ann);
- num_use_ops = NUM_USES (uses);
- vuseops = VUSE_OPS (ann);
-
- /* Any expression which has no virtual operands and no real operands
- should have been propagated if it's possible to do anything with them.
- If this happens here, it probably exists that way for a reason, so we
- won't touch it. An example is:
- b_4 = &tab
- There are no virtual uses nor any real uses, so we just leave this
- alone to be safe. */
-
- if (num_use_ops == 0 && NUM_VUSES (vuseops) == 0)
- return false;
-
- version = SSA_NAME_VERSION (def);
-
- /* Add this expression to the dependency list for each use partition. */
- for (i = 0; i < num_use_ops; i++)
- {
- var = USE_OP (uses, i);
- add_dependance (tab, version, var);
- }
-
- /* If there are VUSES, add a dependence on virtual defs. */
- if (NUM_VUSES (vuseops) != 0)
- {
- add_value_to_list (tab, (value_expr_p *)&(tab->version_info[version]),
- VIRTUAL_PARTITION (tab));
- add_value_to_list (tab,
- &(tab->partition_dep_list[VIRTUAL_PARTITION (tab)]),
- version);
- bitmap_set_bit (tab->partition_in_use, VIRTUAL_PARTITION (tab));
- }
-
- return true;
-}
-
-
-/* This function will remove the expression for VERSION from replacement
- consideration.n table TAB If 'replace' is true, it is marked as
- replaceable, otherwise not. */
-
-static void
-finish_expr (temp_expr_table_p tab, int version, bool replace)
-{
- value_expr_p info, tmp;
- int partition;
-
- /* Remove this expression from its dependent lists. The partition dependence
- list is retained and transfered later to whomever uses this version. */
- for (info = (value_expr_p) tab->version_info[version]; info; info = tmp)
- {
- partition = info->value;
-#ifdef ENABLE_CHECKING
- if (tab->partition_dep_list[partition] == NULL)
- abort ();
-#endif
- tmp = remove_value_from_list (&(tab->partition_dep_list[partition]),
- version);
-#ifdef ENABLE_CHECKING
- if (!tmp)
- abort ();
-#endif
- free_value_expr (tab, tmp);
- /* Only clear the bit when the dependency list is emptied via
- a replacement. Otherwise kill_expr will take care of it. */
- if (!(tab->partition_dep_list[partition]) && replace)
- bitmap_clear_bit (tab->partition_in_use, partition);
- tmp = info->next;
- if (!replace)
- free_value_expr (tab, info);
- }
-
- if (replace)
- {
- tab->saw_replaceable = true;
- bitmap_set_bit (tab->replaceable, version);
- }
- else
- {
-#ifdef ENABLE_CHECKING
- if (bitmap_bit_p (tab->replaceable, version))
- abort ();
-#endif
- tab->version_info[version] = NULL;
- }
-}
-
-
-/* Mark the expression associated with VAR as replaceable, and enter
- the defining stmt into the version_info table TAB. */
-
-static void
-mark_replaceable (temp_expr_table_p tab, tree var)
-{
- value_expr_p info;
- int version = SSA_NAME_VERSION (var);
- finish_expr (tab, version, true);
-
- /* Move the dependence list to the pending list. */
- if (tab->version_info[version])
- {
- info = (value_expr_p) tab->version_info[version];
- for ( ; info->next; info = info->next)
- continue;
- info->next = tab->pending_dependence;
- tab->pending_dependence = (value_expr_p)tab->version_info[version];
- }
-
- tab->version_info[version] = SSA_NAME_DEF_STMT (var);
-}
-
-
-/* This function marks any expression in TAB which is dependent on PARTITION
- as NOT replaceable. CLEAR_BIT is used to determine whether partition_in_use
- should have its bit cleared. Since this routine can be called within an
- EXECUTE_IF_SET_IN_BITMAP, the bit can't always be cleared. */
-
-static inline void
-kill_expr (temp_expr_table_p tab, int partition, bool clear_bit)
-{
- value_expr_p ptr;
-
- /* Mark every active expr dependent on this var as not replaceable. */
- while ((ptr = tab->partition_dep_list[partition]) != NULL)
- finish_expr (tab, ptr->value, false);
-
- if (clear_bit)
- bitmap_clear_bit (tab->partition_in_use, partition);
-}
-
-
-/* This function kills all expressions in TAB which are dependent on virtual
- DEFs. CLEAR_BIT determines whether partition_in_use gets cleared. */
-
-static inline void
-kill_virtual_exprs (temp_expr_table_p tab, bool clear_bit)
-{
- kill_expr (tab, VIRTUAL_PARTITION (tab), clear_bit);
-}
-
-
-/* This function processes basic block BB, and looks for variables which can
- be replaced by their expressions. Results are stored in TAB. */
-
-static void
-find_replaceable_in_bb (temp_expr_table_p tab, basic_block bb)
-{
- block_stmt_iterator bsi;
- tree stmt, def;
- stmt_ann_t ann;
- int partition, num, i;
- use_optype uses;
- def_optype defs;
- var_map map = tab->map;
- value_expr_p p;
-
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- {
- stmt = bsi_stmt (bsi);
- ann = stmt_ann (stmt);
-
- /* Determine if this stmt finishes an existing expression. */
- uses = USE_OPS (ann);
- num = NUM_USES (uses);
- for (i = 0; i < num; i++)
- {
- def = USE_OP (uses, i);
- if (tab->version_info[SSA_NAME_VERSION (def)])
- {
- /* Mark expression as replaceable unless stmt is volatile. */
- if (!ann->has_volatile_ops)
- mark_replaceable (tab, def);
- else
- finish_expr (tab, SSA_NAME_VERSION (def), false);
- }
- }
-
- /* Next, see if this stmt kills off an active expression. */
- defs = DEF_OPS (ann);
- num = NUM_DEFS (defs);
- for (i = 0; i < num; i++)
- {
- def = DEF_OP (defs, i);
- partition = var_to_partition (map, def);
- if (partition != NO_PARTITION && tab->partition_dep_list[partition])
- kill_expr (tab, partition, true);
- }
-
- /* Now see if we are creating a new expression or not. */
- if (!ann->has_volatile_ops)
- check_replaceable (tab, stmt);
-
- /* Free any unused dependency lists. */
- while ((p = tab->pending_dependence))
- {
- tab->pending_dependence = p->next;
- free_value_expr (tab, p);
- }
-
- /* A V_MAY_DEF kills any expression using a virtual operand. */
- if (NUM_V_MAY_DEFS (V_MAY_DEF_OPS (ann)) > 0)
- kill_virtual_exprs (tab, true);
-
- /* A V_MUST_DEF kills any expression using a virtual operand. */
- if (NUM_V_MUST_DEFS (V_MUST_DEF_OPS (ann)) > 0)
- kill_virtual_exprs (tab, true);
- }
-}
-
-
-/* This function is the driver routine for replacement of temporary expressions
- in the SSA->normal phase, operating on MAP. If there are replaceable
- expressions, a table is returned which maps SSA versions to the
- expressions they should be replaced with. A NULL_TREE indicates no
- replacement should take place. If there are no replacements at all,
- NULL is returned by the function, otherwise an expression vector indexed
- by SSA_NAME version numbers. */
-
-static tree *
-find_replaceable_exprs (var_map map)
-{
- basic_block bb;
- int i;
- temp_expr_table_p table;
- tree *ret;
-
- table = new_temp_expr_table (map);
- FOR_EACH_BB (bb)
- {
- find_replaceable_in_bb (table, bb);
- EXECUTE_IF_SET_IN_BITMAP ((table->partition_in_use), 0, i,
- {
- kill_expr (table, i, false);
- });
- }
-
- ret = free_temp_expr_table (table);
- return ret;
-}
-
-
-/* Dump TER expression table EXPR to file F. */
-
-static void
-dump_replaceable_exprs (FILE *f, tree *expr)
-{
- tree stmt, var;
- int x;
- fprintf (f, "\nReplacing Expressions\n");
- for (x = 0; x < (int)num_ssa_names + 1; x++)
- if (expr[x])
- {
- stmt = expr[x];
- var = DEF_OP (STMT_DEF_OPS (stmt), 0);
- print_generic_expr (f, var, TDF_SLIM);
- fprintf (f, " replace with --> ");
- print_generic_expr (f, TREE_OPERAND (stmt, 1), TDF_SLIM);
- fprintf (f, "\n");
- }
- fprintf (f, "\n");
-}
-
-
-/* Helper function for discover_nonconstant_array_refs.
- Look for ARRAY_REF nodes with non-constant indexes and mark them
- addressable. */
-
-static tree
-discover_nonconstant_array_refs_r (tree * tp, int *walk_subtrees,
- void *data ATTRIBUTE_UNUSED)
-{
- tree t = *tp;
-
- if (TYPE_P (t) || DECL_P (t))
- *walk_subtrees = 0;
- else if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
- {
- while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
- && is_gimple_min_invariant (TREE_OPERAND (t, 1))
- && (!TREE_OPERAND (t, 2)
- || is_gimple_min_invariant (TREE_OPERAND (t, 2))))
- || (TREE_CODE (t) == COMPONENT_REF
- && (!TREE_OPERAND (t,2)
- || is_gimple_min_invariant (TREE_OPERAND (t, 2))))
- || TREE_CODE (t) == BIT_FIELD_REF
- || TREE_CODE (t) == REALPART_EXPR
- || TREE_CODE (t) == IMAGPART_EXPR
- || TREE_CODE (t) == VIEW_CONVERT_EXPR
- || TREE_CODE (t) == NOP_EXPR
- || TREE_CODE (t) == CONVERT_EXPR)
- t = TREE_OPERAND (t, 0);
-
- if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
- {
- t = get_base_address (t);
- if (t && DECL_P (t))
- TREE_ADDRESSABLE (t) = 1;
- }
-
- *walk_subtrees = 0;
- }
-
- return NULL_TREE;
-}
-
-
-/* RTL expansion is not able to compile array references with variable
- offsets for arrays stored in single register. Discover such
- expressions and mark variables as addressable to avoid this
- scenario. */
-
-static void
-discover_nonconstant_array_refs (void)
-{
- basic_block bb;
- block_stmt_iterator bsi;
-
- FOR_EACH_BB (bb)
- {
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- walk_tree (bsi_stmt_ptr (bsi), discover_nonconstant_array_refs_r,
- NULL , NULL);
- }
-}
-
-
-/* This function will rewrite the current program using the variable mapping
- found in MAP. If the replacement vector VALUES is provided, any
- occurrences of partitions with non-null entries in the vector will be
- replaced with the expression in the vector instead of its mapped
- variable. */
-
-static void
-rewrite_trees (var_map map, tree *values)
-{
- elim_graph g;
- basic_block bb;
- block_stmt_iterator si;
- edge e;
- tree phi;
- bool changed;
-
-#ifdef ENABLE_CHECKING
- /* 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)
- {
- tree phi;
-
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
- {
- tree T0 = var_to_partition_to_var (map, PHI_RESULT (phi));
-
- if (T0 == NULL_TREE)
- {
- int i;
-
- for (i = 0; i < PHI_NUM_ARGS (phi); i++)
+ tree arg = gimple_phi_arg_def (phi, i);
+ edge e = gimple_phi_arg_edge (phi, i);
+
+ /* 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) != result_var
+ || trivially_conflicts_p (bb, result, arg)))
{
- tree arg = PHI_ARG_DEF (phi, i);
-
- if (TREE_CODE (arg) == SSA_NAME
- && var_to_partition (map, arg) != NO_PARTITION)
+ tree name;
+ gimple stmt, last = NULL;
+ gimple_stmt_iterator gsi2;
+
+ gsi2 = gsi_last_bb (gimple_phi_arg_edge (phi, i)->src);
+ if (!gsi_end_p (gsi2))
+ last = gsi_stmt (gsi2);
+
+ /* In theory the only way we ought to get back to the
+ start of a loop should be with a COND_EXPR or GOTO_EXPR.
+ However, better safe than sorry.
+ If the block ends with a control statement or
+ something that might throw, then we have to
+ insert this assignment before the last
+ statement. Else insert it after the last statement. */
+ if (last && stmt_ends_bb_p (last))
{
- fprintf (stderr, "Argument of PHI is in a partition :(");
- print_generic_expr (stderr, arg, TDF_SLIM);
- fprintf (stderr, "), but the result is not :");
- print_generic_stmt (stderr, phi, TDF_SLIM);
- abort();
+ /* If the last statement in the block is the definition
+ site of the PHI argument, then we can't insert
+ anything after it. */
+ if (TREE_CODE (arg) == SSA_NAME
+ && SSA_NAME_DEF_STMT (arg) == last)
+ continue;
}
- }
- }
- }
- }
-#endif
-
- /* Replace PHI nodes with any required copies. */
- g = new_elim_graph (map->num_partitions);
- g->map = map;
- FOR_EACH_BB (bb)
- {
- for (si = bsi_start (bb); !bsi_end_p (si); )
- {
- size_t i, num_uses, num_defs;
- use_optype uses;
- def_optype defs;
- tree stmt = bsi_stmt (si);
- use_operand_p use_p;
- int remove = 0, is_copy = 0;
- stmt_ann_t ann;
-
- get_stmt_operands (stmt);
- ann = stmt_ann (stmt);
- changed = false;
-
- if (TREE_CODE (stmt) == MODIFY_EXPR
- && (TREE_CODE (TREE_OPERAND (stmt, 1)) == SSA_NAME))
- is_copy = 1;
-
- uses = USE_OPS (ann);
- num_uses = NUM_USES (uses);
-
- for (i = 0; i < num_uses; i++)
- {
- use_p = USE_OP_PTR (uses, i);
- if (replace_use_variable (map, use_p, values))
- changed = true;
- }
-
- defs = DEF_OPS (ann);
- num_defs = NUM_DEFS (defs);
- /* Mark this stmt for removal if it is the list of replaceable
- expressions. */
- if (values && num_defs == 1)
- {
- tree def = DEF_OP (defs, 0);
- tree val;
- val = values[SSA_NAME_VERSION (def)];
- if (val)
- remove = 1;
- }
- if (!remove)
- {
- for (i = 0; i < num_defs; i++)
- {
- def_operand_p def_p = DEF_OP_PTR (defs, i);
-
- if (replace_def_variable (map, def_p, NULL))
- changed = true;
-
- /* If both SSA_NAMEs coalesce to the same variable,
- mark the now redundant copy for removal. */
- if (is_copy
- && num_uses == 1
- && (DEF_FROM_PTR (def_p) == USE_OP (uses, 0)))
- remove = 1;
+ /* Create a new instance of the underlying variable of the
+ PHI result. */
+ stmt = gimple_build_assign (result_var,
+ gimple_phi_arg_def (phi, i));
+ name = make_ssa_name (result_var, stmt);
+ gimple_assign_set_lhs (stmt, name);
+
+ /* Insert the new statement into the block and update
+ the PHI node. */
+ if (last && stmt_ends_bb_p (last))
+ gsi_insert_before (&gsi2, stmt, GSI_NEW_STMT);
+ else
+ gsi_insert_after (&gsi2, stmt, GSI_NEW_STMT);
+ SET_PHI_ARG_DEF (phi, i, name);
}
- if (changed)
- modify_stmt (stmt);
}
-
- /* Remove any stmts marked for removal. */
- if (remove)
- bsi_remove (&si);
- else
- bsi_next (&si);
- }
-
- phi = phi_nodes (bb);
- if (phi)
- {
- for (e = bb->pred; e; e = e->pred_next)
- eliminate_phi (e, phi_arg_from_edge (phi, e), g);
- }
- }
-
- delete_elim_graph (g);
-
- /* If any copies were inserted on edges, actually insert them now. */
- bsi_commit_edge_inserts (NULL);
-}
-
-
-/* Remove the variables specified in MAP from SSA form. Any debug information
- is sent to DUMP. FLAGS indicate what options should be used. */
-
-void
-remove_ssa_form (FILE *dump, var_map map, int flags)
-{
- tree_live_info_p liveinfo;
- basic_block bb;
- tree phi, next;
- FILE *save;
- tree *values = NULL;
-
- save = dump_file;
- dump_file = dump;
-
- /* If we are not combining temps, don't calculate live ranges for variables
- with only one SSA version. */
- if ((flags & SSANORM_COMBINE_TEMPS) == 0)
- compact_var_map (map, VARMAP_NO_SINGLE_DEFS);
- else
- compact_var_map (map, VARMAP_NORMAL);
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- dump_var_map (dump_file, map);
-
- liveinfo = coalesce_ssa_name (map, flags);
-
- /* Make sure even single occurrence variables are in the list now. */
- if ((flags & SSANORM_COMBINE_TEMPS) == 0)
- compact_var_map (map, VARMAP_NORMAL);
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "After Coalescing:\n");
- dump_var_map (dump_file, map);
- }
-
- if (flags & SSANORM_PERFORM_TER)
- {
- values = find_replaceable_exprs (map);
- if (values && dump_file && (dump_flags & TDF_DETAILS))
- dump_replaceable_exprs (dump_file, values);
- }
-
- /* Assign real variables to the partitions now. */
- assign_vars (map);
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "After Root variable replacement:\n");
- dump_var_map (dump_file, map);
- }
-
- if ((flags & SSANORM_COMBINE_TEMPS) && liveinfo)
- {
- coalesce_vars (map, liveinfo);
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "After variable memory coalescing:\n");
- dump_var_map (dump_file, map);
}
- }
-
- if (liveinfo)
- delete_tree_live_info (liveinfo);
- rewrite_trees (map, values);
-
- if (values)
- free (values);
-
- /* Remove phi nodes which have been translated back to real variables. */
- FOR_EACH_BB (bb)
- {
- for (phi = phi_nodes (bb); phi; phi = next)
- {
- next = PHI_CHAIN (phi);
- if ((flags & SSANORM_REMOVE_ALL_PHIS)
- || var_to_partition (map, PHI_RESULT (phi)) != NO_PARTITION)
- remove_phi_node (phi, NULL_TREE, bb);
- }
+ /* Unmark this block again. */
+ bb->aux = NULL;
}
-
- dump_file = save;
}
-
-/* Take a subset of the variables VARS in the current function out of SSA
- form. */
+/* Free all memory associated with going out of SSA form. SA is
+ the outof-SSA info object. */
void
-rewrite_vars_out_of_ssa (bitmap vars)
+finish_out_of_ssa (struct ssaexpand *sa)
{
- if (bitmap_first_set_bit (vars) >= 0)
- {
- var_map map;
- basic_block bb;
- tree phi;
- int i;
- int ssa_flags;
-
- /* Search for PHIs in which one of the PHI arguments is marked for
- translation out of SSA form, but for which the PHI result is not
- marked for translation out of SSA form.
-
- Our per-variable out of SSA translation can not handle that case;
- however we can easily handle it here by creating a new instance
- of the PHI result's underlying variable and initializing it to
- the offending PHI argument on the edge associated with the
- PHI argument. We then change the PHI argument to use our new
- instead of the PHI's underlying variable.
-
- You might think we could register partitions for the out-of-ssa
- translation here and avoid a second walk of the PHI nodes. No
- such luck since the size of the var map will change if we have
- to manually take variables out of SSA form here. */
- FOR_EACH_BB (bb)
- {
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
- {
- tree result = SSA_NAME_VAR (PHI_RESULT (phi));
-
- /* If the definition is marked for renaming, then we need
- to do nothing more for this PHI node. */
- if (bitmap_bit_p (vars, var_ann (result)->uid))
- continue;
-
- /* Look at all the arguments and see if any of them are
- marked for renaming. If so, we need to handle them
- specially. */
- for (i = 0; i < PHI_NUM_ARGS (phi); i++)
- {
- tree arg = PHI_ARG_DEF (phi, i);
-
- /* If the argument is not an SSA_NAME, then we can ignore
- this argument. */
- if (TREE_CODE (arg) != SSA_NAME)
- continue;
-
- /* If this argument is marked for renaming, then we need
- to undo the copy propagation so that we can take
- the argument out of SSA form without taking the
- result out of SSA form. */
- arg = SSA_NAME_VAR (arg);
- if (bitmap_bit_p (vars, var_ann (arg)->uid))
- {
- tree new_name, copy;
-
- /* Get a new SSA_NAME for the copy, it is based on
- the result, not the argument! We use the PHI
- as the definition since we haven't created the
- definition statement yet. */
- new_name = make_ssa_name (result, phi);
-
- /* Now create the copy statement. */
- copy = build (MODIFY_EXPR, TREE_TYPE (arg),
- new_name, PHI_ARG_DEF (phi, i));
-
- /* Now update SSA_NAME_DEF_STMT to point to the
- newly created statement. */
- SSA_NAME_DEF_STMT (new_name) = copy;
-
- /* Now make the argument reference our new SSA_NAME. */
- SET_PHI_ARG_DEF (phi, i, new_name);
-
- /* Queue the statement for insertion. */
- bsi_insert_on_edge (PHI_ARG_EDGE (phi, i), copy);
- modify_stmt (copy);
- }
- }
- }
- }
-
- /* If any copies were inserted on edges, actually insert them now. */
- bsi_commit_edge_inserts (NULL);
-
- /* Now register partitions for all instances of the variables we
- are taking out of SSA form. */
- map = init_var_map (num_ssa_names + 1);
- register_ssa_partitions_for_vars (vars, map);
-
- /* Now that we have all the partitions registered, translate the
- appropriate variables out of SSA form. */
- ssa_flags = SSANORM_COALESCE_PARTITIONS;
- if (flag_tree_combine_temps)
- ssa_flags |= SSANORM_COMBINE_TEMPS;
- remove_ssa_form (dump_file, map, ssa_flags);
-
- /* And finally, reset the out_of_ssa flag for each of the vars
- we just took out of SSA form. */
- EXECUTE_IF_SET_IN_BITMAP (vars, 0, i,
- {
- var_ann (referenced_var (i))->out_of_ssa_tag = 0;
- });
-
- /* Free the map as we are done with it. */
- delete_var_map (map);
-
- }
+ free (sa->partition_to_pseudo);
+ if (sa->values)
+ BITMAP_FREE (sa->values);
+ delete_var_map (sa->map);
+ BITMAP_FREE (sa->partition_has_default_def);
+ memset (sa, 0, sizeof *sa);
}
-
-/* Take the current function out of SSA form, as described in
+/* Take the current function out of SSA form, translating PHIs as described in
R. Morgan, ``Building an Optimizing Compiler'',
Butterworth-Heinemann, Boston, MA, 1998. pp 176-186. */
-static void
-rewrite_out_of_ssa (void)
+unsigned int
+rewrite_out_of_ssa (struct ssaexpand *sa)
{
- var_map map;
- int var_flags = 0;
- int ssa_flags = (SSANORM_REMOVE_ALL_PHIS | SSANORM_USE_COALESCE_LIST);
-
- if (!flag_tree_live_range_split)
- ssa_flags |= SSANORM_COALESCE_PARTITIONS;
-
- eliminate_virtual_phis ();
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- dump_tree_cfg (dump_file, dump_flags & ~TDF_DETAILS);
+ /* If elimination of a PHI requires inserting a copy on a backedge,
+ then we will have to split the backedge which has numerous
+ undesirable performance effects.
- /* We cannot allow unssa to un-gimplify trees before we instrument them. */
- if (flag_tree_ter && !flag_mudflap)
- var_flags = SSA_VAR_MAP_REF_COUNT;
+ A significant number of such cases can be handled here by inserting
+ copies into the loop itself. */
+ insert_backedge_copies ();
- map = create_ssa_var_map (var_flags);
- if (flag_tree_combine_temps)
- ssa_flags |= SSANORM_COMBINE_TEMPS;
- if (flag_tree_ter && !flag_mudflap)
- ssa_flags |= SSANORM_PERFORM_TER;
-
- remove_ssa_form (dump_file, map, ssa_flags);
+ /* Eliminate PHIs which are of no use, such as virtual or dead phis. */
+ eliminate_useless_phis ();
if (dump_file && (dump_flags & TDF_DETAILS))
- dump_tree_cfg (dump_file, dump_flags & ~TDF_DETAILS);
+ gimple_dump_cfg (dump_file, dump_flags & ~TDF_DETAILS);
- /* Do some cleanups which reduce the amount of data the
- tree->rtl expanders deal with. */
- cfg_remove_useless_stmts ();
+ remove_ssa_form (flag_tree_ter, sa);
- /* Flush out flow graph and SSA data. */
- delete_var_map (map);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ gimple_dump_cfg (dump_file, dump_flags & ~TDF_DETAILS);
- /* Mark arrays indexed with non-constant indices with TREE_ADDRESSABLE. */
- discover_nonconstant_array_refs ();
+ return 0;
}
-
-
-/* Define the parameters of the out of SSA pass. */
-
-struct tree_opt_pass pass_del_ssa =
-{
- "optimized", /* name */
- NULL, /* gate */
- rewrite_out_of_ssa, /* execute */
- NULL, /* sub */
- NULL, /* next */
- 0, /* static_pass_number */
- TV_TREE_SSA_TO_NORMAL, /* tv_id */
- PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */
- 0, /* properties_provided */
- /* ??? If TER is enabled, we also kill gimple. */
- PROP_ssa, /* properties_destroyed */
- TODO_verify_ssa | TODO_verify_flow
- | TODO_verify_stmts, /* todo_flags_start */
- TODO_dump_func | TODO_ggc_collect /* todo_flags_finish */
-};
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