/* RTL dead code elimination.
- Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011
- Free Software Foundation, Inc.
+ Copyright (C) 2005-2015 Free Software Foundation, Inc.
This file is part of GCC.
#include "config.h"
#include "system.h"
#include "coretypes.h"
-#include "hashtab.h"
#include "tm.h"
#include "rtl.h"
+#include "alias.h"
+#include "symtab.h"
#include "tree.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "flags.h"
#include "except.h"
+#include "dominance.h"
+#include "cfg.h"
+#include "cfgrtl.h"
+#include "cfgbuild.h"
+#include "cfgcleanup.h"
+#include "predict.h"
+#include "basic-block.h"
#include "df.h"
#include "cselib.h"
#include "dce.h"
/* Instructions that have been marked but whose dependencies have not
yet been processed. */
-static VEC(rtx,heap) *worklist;
+static vec<rtx_insn *> worklist;
/* Bitmap of instructions marked as needed indexed by INSN_UID. */
static sbitmap marked;
static bitmap_obstack dce_blocks_bitmap_obstack;
static bitmap_obstack dce_tmp_bitmap_obstack;
-static bool find_call_stack_args (rtx, bool, bool, bitmap);
+static bool find_call_stack_args (rtx_call_insn *, bool, bool, bitmap);
/* A subroutine for which BODY is part of the instruction being tested;
either the top-level pattern, or an element of a PARALLEL. The
the DCE pass. */
static bool
-deletable_insn_p (rtx insn, bool fast, bitmap arg_stores)
+deletable_insn_p (rtx_insn *insn, bool fast, bitmap arg_stores)
{
rtx body, x;
int i;
+ df_ref def;
if (CALL_P (insn)
/* We cannot delete calls inside of the recursive dce because
infinite loop. */
&& (RTL_CONST_OR_PURE_CALL_P (insn)
&& !RTL_LOOPING_CONST_OR_PURE_CALL_P (insn)))
- return find_call_stack_args (insn, false, fast, arg_stores);
+ return find_call_stack_args (as_a <rtx_call_insn *> (insn), false,
+ fast, arg_stores);
/* Don't delete jumps, notes and the like. */
if (!NONJUMP_INSN_P (insn))
&& !insn_nothrow_p (insn))
return false;
+ /* If INSN sets a global_reg, leave it untouched. */
+ FOR_EACH_INSN_DEF (def, insn)
+ if (HARD_REGISTER_NUM_P (DF_REF_REGNO (def))
+ && global_regs[DF_REF_REGNO (def)])
+ return false;
+ /* Initialization of pseudo PIC register should never be removed. */
+ else if (DF_REF_REG (def) == pic_offset_table_rtx
+ && REGNO (pic_offset_table_rtx) >= FIRST_PSEUDO_REGISTER)
+ return false;
+
body = PATTERN (insn);
switch (GET_CODE (body))
{
/* Return true if INSN has been marked as needed. */
static inline int
-marked_insn_p (rtx insn)
+marked_insn_p (rtx_insn *insn)
{
/* Artificial defs are always needed and they do not have an insn.
We should never see them here. */
gcc_assert (insn);
- return TEST_BIT (marked, INSN_UID (insn));
+ return bitmap_bit_p (marked, INSN_UID (insn));
}
the worklist. */
static void
-mark_insn (rtx insn, bool fast)
+mark_insn (rtx_insn *insn, bool fast)
{
if (!marked_insn_p (insn))
{
if (!fast)
- VEC_safe_push (rtx, heap, worklist, insn);
- SET_BIT (marked, INSN_UID (insn));
+ worklist.safe_push (insn);
+ bitmap_set_bit (marked, INSN_UID (insn));
if (dump_file)
fprintf (dump_file, " Adding insn %d to worklist\n", INSN_UID (insn));
if (CALL_P (insn)
&& !SIBLING_CALL_P (insn)
&& (RTL_CONST_OR_PURE_CALL_P (insn)
&& !RTL_LOOPING_CONST_OR_PURE_CALL_P (insn)))
- find_call_stack_args (insn, true, fast, NULL);
+ find_call_stack_args (as_a <rtx_call_insn *> (insn), true, fast, NULL);
}
}
mark_nonreg_stores_1 (rtx dest, const_rtx pattern, void *data)
{
if (GET_CODE (pattern) != CLOBBER && !REG_P (dest))
- mark_insn ((rtx) data, true);
+ mark_insn ((rtx_insn *) data, true);
}
mark_nonreg_stores_2 (rtx dest, const_rtx pattern, void *data)
{
if (GET_CODE (pattern) != CLOBBER && !REG_P (dest))
- mark_insn ((rtx) data, false);
+ mark_insn ((rtx_insn *) data, false);
}
/* Mark INSN if BODY stores to a non-register destination. */
static void
-mark_nonreg_stores (rtx body, rtx insn, bool fast)
+mark_nonreg_stores (rtx body, rtx_insn *insn, bool fast)
{
if (fast)
note_stores (body, mark_nonreg_stores_1, insn);
going to be marked called again with DO_MARK true. */
static bool
-find_call_stack_args (rtx call_insn, bool do_mark, bool fast,
+find_call_stack_args (rtx_call_insn *call_insn, bool do_mark, bool fast,
bitmap arg_stores)
{
- rtx p, insn, prev_insn;
+ rtx p;
+ rtx_insn *insn, *prev_insn;
bool ret;
HOST_WIDE_INT min_sp_off, max_sp_off;
bitmap sp_bytes;
sp + offset. */
if (!fast)
{
- df_ref *use_rec;
+ df_ref use;
struct df_link *defs;
rtx set;
- for (use_rec = DF_INSN_USES (call_insn); *use_rec; use_rec++)
- if (rtx_equal_p (addr, DF_REF_REG (*use_rec)))
+ FOR_EACH_INSN_USE (use, call_insn)
+ if (rtx_equal_p (addr, DF_REF_REG (use)))
break;
- if (*use_rec == NULL)
+ if (use == NULL)
return false;
- for (defs = DF_REF_CHAIN (*use_rec); defs; defs = defs->next)
+ for (defs = DF_REF_CHAIN (use); defs; defs = defs->next)
if (! DF_REF_IS_ARTIFICIAL (defs->ref))
break;
}
if (addr != stack_pointer_rtx)
{
- df_ref *use_rec;
+ df_ref use;
struct df_link *defs;
rtx set;
- for (use_rec = DF_INSN_USES (call_insn); *use_rec; use_rec++)
- if (rtx_equal_p (addr, DF_REF_REG (*use_rec)))
+ FOR_EACH_INSN_USE (use, call_insn)
+ if (rtx_equal_p (addr, DF_REF_REG (use)))
break;
- for (defs = DF_REF_CHAIN (*use_rec); defs; defs = defs->next)
+ for (defs = DF_REF_CHAIN (use); defs; defs = defs->next)
if (! DF_REF_IS_ARTIFICIAL (defs->ref))
break;
HOST_WIDE_INT off;
if (insn == BB_HEAD (BLOCK_FOR_INSN (call_insn)))
- prev_insn = NULL_RTX;
+ prev_insn = NULL;
else
prev_insn = PREV_INSN (insn);
break;
if (!fast)
{
- df_ref *use_rec;
+ df_ref use;
struct df_link *defs;
rtx set;
- for (use_rec = DF_INSN_USES (insn); *use_rec; use_rec++)
- if (rtx_equal_p (addr, DF_REF_REG (*use_rec)))
+ FOR_EACH_INSN_USE (use, insn)
+ if (rtx_equal_p (addr, DF_REF_REG (use)))
break;
- if (*use_rec == NULL)
+ if (use == NULL)
break;
- for (defs = DF_REF_CHAIN (*use_rec); defs; defs = defs->next)
+ for (defs = DF_REF_CHAIN (use); defs; defs = defs->next)
if (! DF_REF_IS_ARTIFICIAL (defs->ref))
break;
writes to. */
static void
-remove_reg_equal_equiv_notes_for_defs (rtx insn)
+remove_reg_equal_equiv_notes_for_defs (rtx_insn *insn)
{
- df_ref *def_rec;
+ df_ref def;
- for (def_rec = DF_INSN_DEFS (insn); *def_rec; def_rec++)
- remove_reg_equal_equiv_notes_for_regno (DF_REF_REGNO (*def_rec));
+ FOR_EACH_INSN_DEF (def, insn)
+ remove_reg_equal_equiv_notes_for_regno (DF_REF_REGNO (def));
}
/* Scan all BBs for debug insns and reset those that reference values
reset_unmarked_insns_debug_uses (void)
{
basic_block bb;
- rtx insn, next;
+ rtx_insn *insn, *next;
- FOR_EACH_BB_REVERSE (bb)
+ FOR_EACH_BB_REVERSE_FN (bb, cfun)
FOR_BB_INSNS_REVERSE_SAFE (bb, insn, next)
if (DEBUG_INSN_P (insn))
{
- df_ref *use_rec;
+ df_ref use;
- for (use_rec = DF_INSN_USES (insn); *use_rec; use_rec++)
+ FOR_EACH_INSN_USE (use, insn)
{
- df_ref use = *use_rec;
struct df_link *defs;
for (defs = DF_REF_CHAIN (use); defs; defs = defs->next)
{
- rtx ref_insn;
+ rtx_insn *ref_insn;
if (DF_REF_IS_ARTIFICIAL (defs->ref))
continue;
ref_insn = DF_REF_INSN (defs->ref);
delete_unmarked_insns (void)
{
basic_block bb;
- rtx insn, next;
+ rtx_insn *insn, *next;
bool must_clean = false;
- FOR_EACH_BB_REVERSE (bb)
+ FOR_EACH_BB_REVERSE_FN (bb, cfun)
FOR_BB_INSNS_REVERSE_SAFE (bb, insn, next)
if (NONDEBUG_INSN_P (insn))
{
prescan_insns_for_dce (bool fast)
{
basic_block bb;
- rtx insn, prev;
+ rtx_insn *insn, *prev;
bitmap arg_stores = NULL;
if (dump_file)
if (!df_in_progress && ACCUMULATE_OUTGOING_ARGS)
arg_stores = BITMAP_ALLOC (NULL);
- FOR_EACH_BB (bb)
+ FOR_EACH_BB_FN (bb, cfun)
{
FOR_BB_INSNS_REVERSE_SAFE (bb, insn, prev)
if (NONDEBUG_INSN_P (insn))
{
basic_block bb;
struct df_link *defs;
- df_ref *use_rec;
+ df_ref use;
- FOR_ALL_BB (bb)
- {
- for (use_rec = df_get_artificial_uses (bb->index);
- *use_rec; use_rec++)
- for (defs = DF_REF_CHAIN (*use_rec); defs; defs = defs->next)
- if (! DF_REF_IS_ARTIFICIAL (defs->ref))
- mark_insn (DF_REF_INSN (defs->ref), false);
- }
+ FOR_ALL_BB_FN (bb, cfun)
+ FOR_EACH_ARTIFICIAL_USE (use, bb->index)
+ for (defs = DF_REF_CHAIN (use); defs; defs = defs->next)
+ if (!DF_REF_IS_ARTIFICIAL (defs->ref))
+ mark_insn (DF_REF_INSN (defs->ref), false);
}
/* Mark every instruction that defines a register value that INSN uses. */
static void
-mark_reg_dependencies (rtx insn)
+mark_reg_dependencies (rtx_insn *insn)
{
struct df_link *defs;
- df_ref *use_rec;
+ df_ref use;
if (DEBUG_INSN_P (insn))
return;
- for (use_rec = DF_INSN_USES (insn); *use_rec; use_rec++)
+ FOR_EACH_INSN_USE (use, insn)
{
- df_ref use = *use_rec;
if (dump_file)
{
fprintf (dump_file, "Processing use of ");
if (!df_in_progress)
{
if (!fast)
- df_chain_add_problem (DF_UD_CHAIN);
+ {
+ df_set_flags (DF_RD_PRUNE_DEAD_DEFS);
+ df_chain_add_problem (DF_UD_CHAIN);
+ }
df_analyze ();
}
can_alter_cfg = true;
marked = sbitmap_alloc (get_max_uid () + 1);
- sbitmap_zero (marked);
+ bitmap_clear (marked);
}
static unsigned int
rest_of_handle_ud_dce (void)
{
- rtx insn;
+ rtx_insn *insn;
init_dce (false);
prescan_insns_for_dce (false);
mark_artificial_uses ();
- while (VEC_length (rtx, worklist) > 0)
+ while (worklist.length () > 0)
{
- insn = VEC_pop (rtx, worklist);
+ insn = worklist.pop ();
mark_reg_dependencies (insn);
}
- VEC_free (rtx, heap, worklist);
+ worklist.release ();
if (MAY_HAVE_DEBUG_INSNS)
reset_unmarked_insns_debug_uses ();
}
-static bool
-gate_ud_dce (void)
-{
- return optimize > 1 && flag_dce
- && dbg_cnt (dce_ud);
-}
+namespace {
-struct rtl_opt_pass pass_ud_rtl_dce =
+const pass_data pass_data_ud_rtl_dce =
{
- {
- RTL_PASS,
- "ud_dce", /* name */
- gate_ud_dce, /* gate */
- rest_of_handle_ud_dce, /* execute */
- NULL, /* sub */
- NULL, /* next */
- 0, /* static_pass_number */
- TV_DCE, /* tv_id */
- 0, /* properties_required */
- 0, /* properties_provided */
- 0, /* properties_destroyed */
- 0, /* todo_flags_start */
- TODO_df_finish | TODO_verify_rtl_sharing |
- TODO_ggc_collect /* todo_flags_finish */
- }
+ RTL_PASS, /* type */
+ "ud_dce", /* name */
+ OPTGROUP_NONE, /* optinfo_flags */
+ TV_DCE, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_df_finish, /* todo_flags_finish */
};
+class pass_ud_rtl_dce : public rtl_opt_pass
+{
+public:
+ pass_ud_rtl_dce (gcc::context *ctxt)
+ : rtl_opt_pass (pass_data_ud_rtl_dce, ctxt)
+ {}
+
+ /* opt_pass methods: */
+ virtual bool gate (function *)
+ {
+ return optimize > 1 && flag_dce && dbg_cnt (dce_ud);
+ }
+
+ virtual unsigned int execute (function *)
+ {
+ return rest_of_handle_ud_dce ();
+ }
+
+}; // class pass_ud_rtl_dce
+
+} // anon namespace
+
+rtl_opt_pass *
+make_pass_ud_rtl_dce (gcc::context *ctxt)
+{
+ return new pass_ud_rtl_dce (ctxt);
+}
+
/* -------------------------------------------------------------------------
Fast DCE functions
/* Process basic block BB. Return true if the live_in set has
changed. REDO_OUT is true if the info at the bottom of the block
needs to be recalculated before starting. AU is the proper set of
- artificial uses. */
+ artificial uses. Track global substitution of uses of dead pseudos
+ in debug insns using GLOBAL_DEBUG. */
static bool
-word_dce_process_block (basic_block bb, bool redo_out)
+word_dce_process_block (basic_block bb, bool redo_out,
+ struct dead_debug_global *global_debug)
{
bitmap local_live = BITMAP_ALLOC (&dce_tmp_bitmap_obstack);
- rtx insn;
+ rtx_insn *insn;
bool block_changed;
- struct dead_debug debug;
+ struct dead_debug_local debug;
if (redo_out)
{
}
bitmap_copy (local_live, DF_WORD_LR_OUT (bb));
- dead_debug_init (&debug, NULL);
+ dead_debug_local_init (&debug, NULL, global_debug);
FOR_BB_INSNS_REVERSE (bb, insn)
if (DEBUG_INSN_P (insn))
{
- df_ref *use_rec;
- for (use_rec = DF_INSN_USES (insn); *use_rec; use_rec++)
- if (DF_REF_REGNO (*use_rec) >= FIRST_PSEUDO_REGISTER
- && (GET_MODE_SIZE (GET_MODE (DF_REF_REAL_REG (*use_rec)))
+ df_ref use;
+ FOR_EACH_INSN_USE (use, insn)
+ if (DF_REF_REGNO (use) >= FIRST_PSEUDO_REGISTER
+ && (GET_MODE_SIZE (GET_MODE (DF_REF_REAL_REG (use)))
== 2 * UNITS_PER_WORD)
- && !bitmap_bit_p (local_live, 2 * DF_REF_REGNO (*use_rec))
- && !bitmap_bit_p (local_live, 2 * DF_REF_REGNO (*use_rec) + 1))
- dead_debug_add (&debug, *use_rec, DF_REF_REGNO (*use_rec));
+ && !bitmap_bit_p (local_live, 2 * DF_REF_REGNO (use))
+ && !bitmap_bit_p (local_live, 2 * DF_REF_REGNO (use) + 1))
+ dead_debug_add (&debug, use, DF_REF_REGNO (use));
}
else if (INSN_P (insn))
{
death. */
if (debug.used && !bitmap_empty_p (debug.used))
{
- df_ref *def_rec;
-
- for (def_rec = DF_INSN_DEFS (insn); *def_rec; def_rec++)
- dead_debug_insert_temp (&debug, DF_REF_REGNO (*def_rec), insn,
- DEBUG_TEMP_BEFORE_WITH_VALUE);
+ df_ref def;
+
+ FOR_EACH_INSN_DEF (def, insn)
+ dead_debug_insert_temp (&debug, DF_REF_REGNO (def), insn,
+ marked_insn_p (insn)
+ && !control_flow_insn_p (insn)
+ ? DEBUG_TEMP_AFTER_WITH_REG_FORCE
+ : DEBUG_TEMP_BEFORE_WITH_VALUE);
}
if (dump_file)
if (block_changed)
bitmap_copy (DF_WORD_LR_IN (bb), local_live);
- dead_debug_finish (&debug, NULL);
+ dead_debug_local_finish (&debug, NULL);
BITMAP_FREE (local_live);
return block_changed;
}
/* Process basic block BB. Return true if the live_in set has
changed. REDO_OUT is true if the info at the bottom of the block
needs to be recalculated before starting. AU is the proper set of
- artificial uses. */
+ artificial uses. Track global substitution of uses of dead pseudos
+ in debug insns using GLOBAL_DEBUG. */
static bool
-dce_process_block (basic_block bb, bool redo_out, bitmap au)
+dce_process_block (basic_block bb, bool redo_out, bitmap au,
+ struct dead_debug_global *global_debug)
{
bitmap local_live = BITMAP_ALLOC (&dce_tmp_bitmap_obstack);
- rtx insn;
+ rtx_insn *insn;
bool block_changed;
- df_ref *def_rec;
- struct dead_debug debug;
+ df_ref def;
+ struct dead_debug_local debug;
if (redo_out)
{
bitmap_copy (local_live, DF_LR_OUT (bb));
df_simulate_initialize_backwards (bb, local_live);
- dead_debug_init (&debug, NULL);
+ dead_debug_local_init (&debug, NULL, global_debug);
FOR_BB_INSNS_REVERSE (bb, insn)
if (DEBUG_INSN_P (insn))
{
- df_ref *use_rec;
- for (use_rec = DF_INSN_USES (insn); *use_rec; use_rec++)
- if (!bitmap_bit_p (local_live, DF_REF_REGNO (*use_rec))
- && !bitmap_bit_p (au, DF_REF_REGNO (*use_rec)))
- dead_debug_add (&debug, *use_rec, DF_REF_REGNO (*use_rec));
+ df_ref use;
+ FOR_EACH_INSN_USE (use, insn)
+ if (!bitmap_bit_p (local_live, DF_REF_REGNO (use))
+ && !bitmap_bit_p (au, DF_REF_REGNO (use)))
+ dead_debug_add (&debug, use, DF_REF_REGNO (use));
}
else if (INSN_P (insn))
{
/* The insn is needed if there is someone who uses the output. */
if (!needed)
- for (def_rec = DF_INSN_DEFS (insn); *def_rec; def_rec++)
- if (bitmap_bit_p (local_live, DF_REF_REGNO (*def_rec))
- || bitmap_bit_p (au, DF_REF_REGNO (*def_rec)))
+ FOR_EACH_INSN_DEF (def, insn)
+ if (bitmap_bit_p (local_live, DF_REF_REGNO (def))
+ || bitmap_bit_p (au, DF_REF_REGNO (def)))
{
needed = true;
mark_insn (insn, true);
was marked, in case the debug use was after the point of
death. */
if (debug.used && !bitmap_empty_p (debug.used))
- for (def_rec = DF_INSN_DEFS (insn); *def_rec; def_rec++)
- dead_debug_insert_temp (&debug, DF_REF_REGNO (*def_rec), insn,
- DEBUG_TEMP_BEFORE_WITH_VALUE);
+ FOR_EACH_INSN_DEF (def, insn)
+ dead_debug_insert_temp (&debug, DF_REF_REGNO (def), insn,
+ needed && !control_flow_insn_p (insn)
+ ? DEBUG_TEMP_AFTER_WITH_REG_FORCE
+ : DEBUG_TEMP_BEFORE_WITH_VALUE);
}
- dead_debug_finish (&debug, NULL);
+ dead_debug_local_finish (&debug, NULL);
df_simulate_finalize_backwards (bb, local_live);
block_changed = !bitmap_equal_p (local_live, DF_LR_IN (bb));
bitmap au = &df->regular_block_artificial_uses;
bitmap au_eh = &df->eh_block_artificial_uses;
int i;
+ struct dead_debug_global global_debug;
prescan_insns_for_dce (true);
for (i = 0; i < n_blocks; i++)
bitmap_set_bit (all_blocks, postorder[i]);
+ dead_debug_global_init (&global_debug, NULL);
+
while (global_changed)
{
global_changed = false;
for (i = 0; i < n_blocks; i++)
{
int index = postorder[i];
- basic_block bb = BASIC_BLOCK (index);
+ basic_block bb = BASIC_BLOCK_FOR_FN (cfun, index);
bool local_changed;
if (index < NUM_FIXED_BLOCKS)
if (word_level)
local_changed
- = word_dce_process_block (bb, bitmap_bit_p (redo_out, index));
+ = word_dce_process_block (bb, bitmap_bit_p (redo_out, index),
+ &global_debug);
else
local_changed
= dce_process_block (bb, bitmap_bit_p (redo_out, index),
- bb_has_eh_pred (bb) ? au_eh : au);
+ bb_has_eh_pred (bb) ? au_eh : au,
+ &global_debug);
bitmap_set_bit (processed, index);
if (local_changed)
/* So something was deleted that requires a redo. Do it on
the cheap. */
delete_unmarked_insns ();
- sbitmap_zero (marked);
+ bitmap_clear (marked);
bitmap_clear (processed);
bitmap_clear (redo_out);
}
}
+ dead_debug_global_finish (&global_debug, NULL);
+
delete_unmarked_insns ();
BITMAP_FREE (processed);
}
-static bool
-gate_fast_dce (void)
-{
- return optimize > 0 && flag_dce
- && dbg_cnt (dce_fast);
-}
+namespace {
-struct rtl_opt_pass pass_fast_rtl_dce =
+const pass_data pass_data_fast_rtl_dce =
{
- {
- RTL_PASS,
- "rtl_dce", /* name */
- gate_fast_dce, /* gate */
- rest_of_handle_fast_dce, /* execute */
- NULL, /* sub */
- NULL, /* next */
- 0, /* static_pass_number */
- TV_DCE, /* tv_id */
- 0, /* properties_required */
- 0, /* properties_provided */
- 0, /* properties_destroyed */
- 0, /* todo_flags_start */
- TODO_df_finish | TODO_verify_rtl_sharing |
- TODO_ggc_collect /* todo_flags_finish */
- }
+ RTL_PASS, /* type */
+ "rtl_dce", /* name */
+ OPTGROUP_NONE, /* optinfo_flags */
+ TV_DCE, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_df_finish, /* todo_flags_finish */
};
+
+class pass_fast_rtl_dce : public rtl_opt_pass
+{
+public:
+ pass_fast_rtl_dce (gcc::context *ctxt)
+ : rtl_opt_pass (pass_data_fast_rtl_dce, ctxt)
+ {}
+
+ /* opt_pass methods: */
+ virtual bool gate (function *)
+ {
+ return optimize > 0 && flag_dce && dbg_cnt (dce_fast);
+ }
+
+ virtual unsigned int execute (function *)
+ {
+ return rest_of_handle_fast_dce ();
+ }
+
+}; // class pass_fast_rtl_dce
+
+} // anon namespace
+
+rtl_opt_pass *
+make_pass_fast_rtl_dce (gcc::context *ctxt)
+{
+ return new pass_fast_rtl_dce (ctxt);
+}