/* Convert a program in SSA form into Normal form.
- Copyright (C) 2004, 2005 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, 51 Franklin Street, Fifth Floor,
-Boston, MA 02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "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 "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 "hashtab.h"
#include "tree-dump.h"
#include "tree-ssa-live.h"
#include "tree-pass.h"
#include "toplev.h"
-#include "vecprim.h"
-/* Flags to pass to remove_ssa_form. */
-
-#define SSANORM_PERFORM_TER 0x1
-#define SSANORM_COALESCE_PARTITIONS 0x4
/* 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
} *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);
-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, 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. */
}
DECL_ARTIFICIAL (tmp) = DECL_ARTIFICIAL (t);
DECL_IGNORED_P (tmp) = DECL_IGNORED_P (t);
+ DECL_GIMPLE_REG_P (tmp) = DECL_GIMPLE_REG_P (t);
add_referenced_var (tmp);
/* add_referenced_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)->symbol_mem_tag = var_ann (t)->symbol_mem_tag;
+ set_symbol_mem_tag (tmp, symbol_mem_tag (t));
if (is_call_clobbered (t))
mark_call_clobbered (tmp, var_ann (t)->escape_mask);
{
tree copy;
- copy = build2 (GIMPLE_MODIFY_STMT, TREE_TYPE (dest), dest, src);
+ copy = build_gimple_modify_stmt (dest, src);
set_is_used (dest);
if (TREE_CODE (src) == ADDR_EXPR)
}
+
/* Eliminate all the phi nodes on edge E in graph G. */
static void
}
-/* Shortcut routine to print messages to file F of the form:
- "STR1 EXPR1 STR2 EXPR2 STR3." */
-
-static void
-print_exprs (FILE *f, const char *str1, tree expr1, const char *str2,
- tree expr2, const char *str3)
-{
- 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, z;
- edge_iterator ei;
-
- /* Code cannot be inserted on abnormal edges. Look for all abnormal
- edges, and coalesce any PHI results with their arguments across
- that edge. */
-
- FOR_EACH_BB (bb)
- FOR_EACH_EDGE (e, ei, bb->succs)
- 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);
-
- /* Ignore results which are not relevant. */
- if (x == NO_PARTITION)
- continue;
-
- tmp = PHI_ARG_DEF (phi, e->dest_idx);
-#ifdef ENABLE_CHECKING
- if (!phi_ssa_name_p (tmp))
- {
- print_exprs_edge (stderr, e,
- "\nConstant argument in PHI. Can't insert :",
- var, " = ", tmp);
- internal_error ("SSA corruption");
- }
-#else
- gcc_assert (phi_ssa_name_p (tmp));
-#endif
- y = var_to_partition (map, tmp);
- gcc_assert (x != NO_PARTITION);
- gcc_assert (y != NO_PARTITION);
-#ifdef ENABLE_CHECKING
- 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)));
- internal_error ("SSA corruption");
- }
-#else
- gcc_assert (root_var_find (rv, x) == root_var_find (rv, y));
-#endif
-
- if (x != y)
- {
-#ifdef ENABLE_CHECKING
- if (conflict_graph_conflict_p (graph, x, y))
- {
- print_exprs_edge (stderr, e, "\n Conflict ",
- partition_to_var (map, x),
- " and ", partition_to_var (map, y));
- internal_error ("SSA corruption");
- }
-#else
- gcc_assert (!conflict_graph_conflict_p (graph, x, y));
-#endif
-
- /* 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);
- }
- z = var_union (map, var, tmp);
-#ifdef ENABLE_CHECKING
- if (z == NO_PARTITION)
- {
- print_exprs_edge (stderr, e, "\nUnable to coalesce",
- partition_to_var (map, x), " and ",
- partition_to_var (map, y));
- internal_error ("SSA corruption");
- }
-#else
- gcc_assert (z != NO_PARTITION);
-#endif
- gcc_assert (z == x || z == y);
- if (z == x)
- conflict_graph_merge_regs (graph, x, y);
- else
- conflict_graph_merge_regs (graph, y, x);
- }
- }
-}
-
-/* Coalesce potential copies via PHI arguments. */
-
-static void
-coalesce_phi_operands (var_map map, coalesce_list_p cl)
-{
- basic_block bb;
- tree phi;
-
- FOR_EACH_BB (bb)
- {
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
- {
- tree res = PHI_RESULT (phi);
- int p = var_to_partition (map, res);
- int x;
-
- 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)
- {
- edge e = PHI_ARG_EDGE (phi, x);
- add_coalesce (cl, p, p2,
- coalesce_cost (EDGE_FREQUENCY (e),
- maybe_hot_bb_p (bb),
- EDGE_CRITICAL_P (e)));
- }
- }
- }
- }
-}
-
-/* Coalesce all the result decls together. */
-
-static void
-coalesce_result_decls (var_map map, coalesce_list_p cl)
-{
- unsigned int i, x;
- tree var = NULL;
-
- for (i = x = 0; x < num_var_partitions (map); x++)
- {
- tree p = partition_to_var (map, x);
- if (TREE_CODE (SSA_NAME_VAR (p)) == RESULT_DECL)
- {
- if (var == NULL_TREE)
- {
- var = p;
- i = x;
- }
- else
- add_coalesce (cl, i, x,
- coalesce_cost (EXIT_BLOCK_PTR->frequency,
- maybe_hot_bb_p (EXIT_BLOCK_PTR),
- false));
- }
- }
-}
-
-/* Coalesce matching constraints in asms. */
-
-static void
-coalesce_asm_operands (var_map map, coalesce_list_p cl)
-{
- basic_block bb;
-
- FOR_EACH_BB (bb)
- {
- block_stmt_iterator bsi;
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- {
- tree stmt = bsi_stmt (bsi);
- unsigned long noutputs, i;
- tree *outputs, link;
-
- if (TREE_CODE (stmt) != ASM_EXPR)
- continue;
-
- noutputs = list_length (ASM_OUTPUTS (stmt));
- outputs = (tree *) alloca (noutputs * sizeof (tree));
- for (i = 0, link = ASM_OUTPUTS (stmt); link;
- ++i, link = TREE_CHAIN (link))
- outputs[i] = TREE_VALUE (link);
-
- for (link = ASM_INPUTS (stmt); link; link = TREE_CHAIN (link))
- {
- const char *constraint
- = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
- tree input = TREE_VALUE (link);
- char *end;
- unsigned long match;
- int p1, p2;
-
- if (TREE_CODE (input) != SSA_NAME && !DECL_P (input))
- continue;
-
- match = strtoul (constraint, &end, 10);
- if (match >= noutputs || end == constraint)
- continue;
-
- if (TREE_CODE (outputs[match]) != SSA_NAME
- && !DECL_P (outputs[match]))
- continue;
-
- p1 = var_to_partition (map, outputs[match]);
- if (p1 == NO_PARTITION)
- continue;
- p2 = var_to_partition (map, input);
- if (p2 == NO_PARTITION)
- continue;
-
- add_coalesce (cl, p1, p2, coalesce_cost (REG_BR_PROB_BASE,
- maybe_hot_bb_p (bb),
- false));
- }
- }
- }
-}
-
-/* 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)
-{
- unsigned num, x;
- sbitmap live;
- root_var_p rv;
- tree_live_info_p liveinfo;
- conflict_graph graph;
- coalesce_list_p cl = NULL;
- sbitmap_iterator sbi;
-
- if (num_var_partitions (map) <= 1)
- return NULL;
-
- liveinfo = calculate_live_ranges (map);
- rv = root_var_init (map);
-
- /* Remove single element variable from the list. */
- root_var_compact (rv);
-
- cl = create_coalesce_list (map);
-
- coalesce_phi_operands (map, cl);
- coalesce_result_decls (map, cl);
- coalesce_asm_operands (map, cl);
-
- /* 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. */
-
- num = num_var_partitions (map);
- live = sbitmap_alloc (num);
- sbitmap_zero (live);
-
- /* Set 'live' vector to indicate live on entry partitions. */
- for (x = 0 ; x < num; x++)
- {
- tree var = partition_to_var (map, x);
- if (gimple_default_def (cfun, SSA_NAME_VAR (var)) == var)
- SET_BIT (live, x);
- }
-
- delete_tree_live_info (liveinfo);
- liveinfo = NULL;
-
- /* Assign root variable as partition representative for each live on entry
- partition. */
- EXECUTE_IF_SET_IN_SBITMAP (live, 0, x, sbi)
- {
- tree var = root_var (rv, root_var_find (rv, x));
- var_ann_t ann = var_ann (var);
- /* If these aren't already coalesced... */
- if (partition_to_var (map, x) != var)
- {
- /* This root variable should have not already been assigned
- to another partition which is not coalesced with this one. */
- gcc_assert (!ann->out_of_ssa_tag);
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- print_exprs (dump_file, "Must coalesce ",
- partition_to_var (map, x),
- " with the root variable ", var, ".\n");
- }
-
- change_partition_var (map, var, x);
- }
- }
-
- sbitmap_free (live);
-
- /* Coalesce partitions live across abnormal edges. */
- coalesce_abnormal_edges (map, graph, rv);
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- dump_var_map (dump_file, map);
-
- /* Coalesce partitions. */
- coalesce_tpa_members (rv, graph, map, cl,
- ((dump_flags & TDF_DETAILS) ? dump_file
- : NULL));
-
- 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;
-}
-
-
/* Take the ssa-name var_map MAP, and assign real variables to each
partition. */
static void
assign_vars (var_map map)
{
- int x, i, num, rep;
- tree t, var;
+ int x, num;
+ tree var, root;
var_ann_t ann;
- root_var_p rv;
-
- rv = root_var_init (map);
- if (!rv)
- return;
-
- /* Coalescing may already have forced some partitions to their root
- variable. Find these and tag them. */
num = num_var_partitions (map);
for (x = 0; x < num; x++)
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;
+ /* It must already be coalesced. */
+ gcc_assert (ann->out_of_ssa_tag == 1);
if (dump_file && (dump_flags & TDF_DETAILS))
{
- fprintf (dump_file, "partition %d has variable ", x);
+ fprintf (dump_file, "partition %d already has variable ", x);
print_generic_expr (dump_file, var, TDF_SLIM);
fprintf (dump_file, " assigned to it.\n");
}
-
}
- }
-
- num = root_var_num (rv);
- for (x = 0; x < num; x++)
- {
- 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)
+ else
+ {
+ root = SSA_NAME_VAR (var);
+ ann = var_ann (root);
+ /* If ROOT is already associated, create a new one. */
+ 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;
+ root = create_temp (root);
+ ann = var_ann (root);
}
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- print_exprs (dump_file, "", t, " not coalesced with ", var,
- "");
-
- var = create_temp (t);
- change_partition_var (map, var, rep);
- ann = var_ann (var);
-
+ /* ROOT has not been coalesced yet, so use it. */
if (dump_file && (dump_flags & TDF_DETAILS))
{
- fprintf (dump_file, " --> New temp: '");
- print_generic_expr (dump_file, var, TDF_SLIM);
- fprintf (dump_file, "'\n");
+ fprintf (dump_file, "Partition %d is assigned to var ", x);
+ print_generic_stmt (dump_file, root, TDF_SLIM);
}
+ change_partition_var (map, root, x);
}
}
-
- root_var_delete (rv);
}
{
tree new_expr = GIMPLE_STMT_OPERAND (expr[version], 1);
SET_USE (p, new_expr);
+
/* Clear the stmt's RHS, or GC might bite us. */
GIMPLE_STMT_OPERAND (expr[version], 1) = NULL_TREE;
return true;
tree new_var;
tree var = DEF_FROM_PTR (def_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_DEF (def_p, new_expr);
- /* Clear the stmt's RHS, or GC might bite us. */
- TREE_OPERAND (expr[version], 1) = NULL_TREE;
- return true;
- }
- }
+ /* Do nothing if we are replacing this variable with an expression. */
+ if (expr && expr[SSA_NAME_VERSION (var)])
+ return true;
new_var = var_to_partition_to_var (map, var);
if (new_var)
}
}
#endif
- remove_phi_node (phi, NULL_TREE);
+ remove_phi_node (phi, NULL_TREE, true);
}
}
}
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 = PHI_ARG_DEF (phi, i);
if (remove)
bsi_remove (&si, true);
else
- bsi_next (&si);
+ {
+ if (changed)
+ if (maybe_clean_or_replace_eh_stmt (stmt, stmt))
+ tree_purge_dead_eh_edges (bb);
+ bsi_next (&si);
+ }
}
phi = phi_nodes (bb);
/* Pass this function to make_forwarder_block so that all the edges with
- matching PENDING_STMT lists to 'curr_stmt_list' get redirected. */
-static bool
+ matching PENDING_STMT lists to 'curr_stmt_list' get redirected. E is the
+ edge to test for a match. */
+
+static inline bool
same_stmt_list_p (edge e)
{
return (e->aux == (PTR) leader_match) ? true : false;
/* Return TRUE if S1 and S2 are equivalent copies. */
+
static inline bool
-identical_copies_p (tree s1, tree s2)
+identical_copies_p (const_tree s1, const_tree s2)
{
#ifdef ENABLE_CHECKING
gcc_assert (TREE_CODE (s1) == GIMPLE_MODIFY_STMT);
}
-/* Compare the PENDING_STMT list for two edges, and return true if the lists
+/* Compare the PENDING_STMT list for edges E1 and E2. Return true if the lists
contain the same sequence of copies. */
static inline bool
-identical_stmt_lists_p (edge e1, edge e2)
+identical_stmt_lists_p (const_edge e1, const_edge e2)
{
tree t1 = PENDING_STMT (e1);
tree t2 = PENDING_STMT (e2);
bsi_commit_one_edge_insert (e, NULL);
return;
}
+
/* Find out how many edges there are with interesting pending stmts on them.
Commit the stmts on edges we are not interested in. */
FOR_EACH_EDGE (e, ei, bb->preds)
return;
}
-
if (dump_file)
fprintf (dump_file, "\nOpportunities in BB %d for stmt/block reduction:\n",
bb->index);
-
/* For each common list, create a forwarding block and issue the stmt's
in that block. */
}
-/* Remove the variables specified in MAP from SSA form. FLAGS indicate what
- options should be used. */
+/* 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
-remove_ssa_form (var_map map, int flags)
+remove_ssa_form (bool perform_ter)
{
- tree_live_info_p liveinfo;
basic_block bb;
tree phi, next;
tree *values = NULL;
+ var_map map;
- /* If we are not combining temps, don't calculate live ranges for variables
- with only one SSA version. */
- compact_var_map (map, VARMAP_NO_SINGLE_DEFS);
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- dump_var_map (dump_file, map);
-
- liveinfo = coalesce_ssa_name (map, flags);
+ map = coalesce_ssa_name ();
- /* Make sure even single occurrence variables are in the list now. */
- compact_var_map (map, VARMAP_NORMAL);
+ /* Return to viewing the variable list as just all reference variables after
+ coalescing has been performed. */
+ partition_view_normal (map, false);
if (dump_file && (dump_flags & TDF_DETAILS))
{
dump_var_map (dump_file, map);
}
- if (flags & SSANORM_PERFORM_TER)
+ if (perform_ter)
{
values = find_replaceable_exprs (map);
if (values && dump_file && (dump_flags & TDF_DETAILS))
if (dump_file && (dump_flags & TDF_DETAILS))
{
- fprintf (dump_file, "After Root variable replacement:\n");
+ fprintf (dump_file, "After Base variable replacement:\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. */
+ /* 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);
- remove_phi_node (phi, NULL_TREE);
+ remove_phi_node (phi, NULL_TREE, true);
}
}
- /* we no longer maintain the SSA operand cache at this point. */
- fini_ssa_operands ();
-
/* If any copies were inserted on edges, analyze and insert them now. */
perform_edge_inserts ();
+
+ delete_var_map (map);
}
+
/* 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
tree arg = PHI_ARG_DEF (phi, i);
edge e = 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 and
- we are not combining temporaries, then we will
- need a copy statement. */
+ /* 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))
/* 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
continue;
}
- /* Create a new instance of the underlying
- variable of the PHI result. */
- stmt = build2 (GIMPLE_MODIFY_STMT, TREE_TYPE (result_var),
- NULL_TREE, PHI_ARG_DEF (phi, i));
+ /* Create a new instance of the underlying variable of the
+ PHI result. */
+ stmt = build_gimple_modify_stmt (NULL_TREE,
+ PHI_ARG_DEF (phi, i));
name = make_ssa_name (result_var, stmt);
GIMPLE_STMT_OPERAND (stmt, 0) = name;
}
}
-/* 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 unsigned int
rewrite_out_of_ssa (void)
{
- var_map map;
- int ssa_flags = 0;
-
/* 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.
copies into the loop itself. */
insert_backedge_copies ();
- 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);
- map = create_ssa_var_map ();
-
- if (flag_tree_ter && !flag_mudflap)
- ssa_flags |= SSANORM_PERFORM_TER;
-
- remove_ssa_form (map, ssa_flags);
+ remove_ssa_form (flag_tree_ter && !flag_mudflap);
if (dump_file && (dump_flags & TDF_DETAILS))
dump_tree_cfg (dump_file, dump_flags & ~TDF_DETAILS);
- /* Flush out flow graph and SSA data. */
- delete_var_map (map);
-
cfun->gimple_df->in_ssa_p = false;
return 0;
}
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