/* Control flow graph manipulation code for GNU compiler.
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001 Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
This file is part of GCC.
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
-/* This file contains low level functions to manipulate with CFG and analyze it.
- All other modules should not transform the datastructure directly and use
- abstraction instead. The file is supposed to be ordered bottom-up.
+/* This file contains low level functions to manipulate the CFG and
+ analyze it. All other modules should not transform the data structure
+ directly and use abstraction instead. The file is supposed to be
+ ordered bottom-up and should not contain any code dependent on a
+ particular intermediate language (RTL or trees).
Available functionality:
- Initialization/deallocation
init_flow, clear_edges
- - CFG aware instruction chain manipulation
- delete_insn, delete_insn_chain
- - Basic block manipulation
- create_basic_block, flow_delete_block, split_block, merge_blocks_nomove
- - Infrastructure to determine quickly basic block for instruction.
- compute_bb_for_insn, update_bb_for_insn, set_block_for_insn,
- set_block_for_new_insns
+ - Low level basic block manipulation
+ alloc_block, expunge_block
- Edge manipulation
make_edge, make_single_succ_edge, cached_make_edge, remove_edge
- Low level edge redirection (without updating instruction chain)
redirect_edge_succ, redirect_edge_succ_nodup, redirect_edge_pred
- - High level edge redirection (with updating and optimizing instruction
- chain)
- block_label, redirect_edge_and_branch,
- redirect_edge_and_branch_force, tidy_fallthru_edge, force_nonfallthru
- - Edge splitting and commiting to edges
- split_edge, insert_insn_on_edge, commit_edge_insertions
- - Dumpipng and debugging
- dump_flow_info, debug_flow_info, dump_edge_info, dump_bb, debug_bb,
- debug_bb_n, print_rtl_with_bb
- - Consistency checking
- verify_flow_info
- - CFG updating after constant propagation
- purge_dead_edges, purge_all_dead_edges
+ - Dumping and debugging
+ dump_flow_info, debug_flow_info, dump_edge_info
+ - Allocation of AUX fields for basic blocks
+ alloc_aux_for_blocks, free_aux_for_blocks, alloc_aux_for_block
+ - clear_bb_flags
+ - Consistency checking
+ verify_flow_info
+ - Dumping and debugging
+ print_rtl_with_bb, dump_bb, debug_bb, debug_bb_n
*/
\f
#include "config.h"
#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
#include "tree.h"
#include "rtl.h"
#include "hard-reg-set.h"
#include "toplev.h"
#include "tm_p.h"
#include "obstack.h"
-
-
-/* Stubs in case we haven't got a return insn. */
-#ifndef HAVE_return
-#define HAVE_return 0
-#define gen_return() NULL_RTX
-#endif
+#include "alloc-pool.h"
/* The obstack on which the flow graph components are allocated. */
struct obstack flow_obstack;
static char *flow_firstobj;
+/* Basic block object pool. */
+
+static alloc_pool bb_pool;
+
+/* Edge object pool. */
+
+static alloc_pool edge_pool;
+
/* Number of basic blocks in the current function. */
int n_basic_blocks;
-/* Number of edges in the current function. */
+/* First free basic block number. */
-int n_edges;
+int last_basic_block;
-/* First edge in the deleted edges chain. */
+/* Number of edges in the current function. */
-edge first_deleted_edge;
+int n_edges;
/* The basic block array. */
NULL, /* global_live_at_end */
NULL, /* aux */
ENTRY_BLOCK, /* index */
+ NULL, /* prev_bb */
+ EXIT_BLOCK_PTR, /* next_bb */
0, /* loop_depth */
+ NULL, /* loop_father */
+ { NULL, NULL }, /* dom */
0, /* count */
0, /* frequency */
- 0 /* flags */
+ 0, /* flags */
+ NULL /* rbi */
},
{
NULL, /* head */
NULL, /* global_live_at_end */
NULL, /* aux */
EXIT_BLOCK, /* index */
+ ENTRY_BLOCK_PTR, /* prev_bb */
+ NULL, /* next_bb */
0, /* loop_depth */
+ NULL, /* loop_father */
+ { NULL, NULL }, /* dom */
0, /* count */
0, /* frequency */
- 0 /* flags */
+ 0, /* flags */
+ NULL /* rbi */
}
};
-/* The basic block structure for every insn, indexed by uid. */
-
-varray_type basic_block_for_insn;
-
-/* The labels mentioned in non-jump rtl. Valid during find_basic_blocks. */
-/* ??? Should probably be using LABEL_NUSES instead. It would take a
- bit of surgery to be able to use or co-opt the routines in jump. */
-
-rtx label_value_list;
-rtx tail_recursion_label_list;
-
-void debug_flow_info PARAMS ((void));
-static int can_delete_note_p PARAMS ((rtx));
-static int can_delete_label_p PARAMS ((rtx));
-static void commit_one_edge_insertion PARAMS ((edge));
-static bool try_redirect_by_replacing_jump PARAMS ((edge, basic_block));
-static rtx last_loop_beg_note PARAMS ((rtx));
-static bool back_edge_of_syntactic_loop_p PARAMS ((basic_block, basic_block));
-static basic_block force_nonfallthru_and_redirect PARAMS ((edge, basic_block));
+void debug_flow_info (void);
+static void free_edge (edge);
\f
-/* Called once at intialization time. */
+/* Called once at initialization time. */
void
-init_flow ()
+init_flow (void)
{
static int initialized;
- first_deleted_edge = 0;
n_edges = 0;
if (!initialized)
{
gcc_obstack_init (&flow_obstack);
- flow_firstobj = (char *) obstack_alloc (&flow_obstack, 0);
+ flow_firstobj = obstack_alloc (&flow_obstack, 0);
initialized = 1;
}
else
{
+ free_alloc_pool (bb_pool);
+ free_alloc_pool (edge_pool);
obstack_free (&flow_obstack, flow_firstobj);
- flow_firstobj = (char *) obstack_alloc (&flow_obstack, 0);
- }
-}
-\f
-/* Free the memory associated with the edge structures. */
-
-void
-clear_edges ()
-{
- int i;
-
- for (i = 0; i < n_basic_blocks; ++i)
- {
- basic_block bb = BASIC_BLOCK (i);
-
- while (bb->succ)
- remove_edge (bb->succ);
+ flow_firstobj = obstack_alloc (&flow_obstack, 0);
}
-
- while (ENTRY_BLOCK_PTR->succ)
- remove_edge (ENTRY_BLOCK_PTR->succ);
-
- if (n_edges)
- abort ();
+ bb_pool = create_alloc_pool ("Basic block pool",
+ sizeof (struct basic_block_def), 100);
+ edge_pool = create_alloc_pool ("Edge pool",
+ sizeof (struct edge_def), 100);
}
\f
-/* Return true if NOTE is not one of the ones that must be kept paired,
- so that we may simply delete them. */
-
-static int
-can_delete_note_p (note)
- rtx note;
-{
- return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED
- || NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK);
-}
+/* Helper function for remove_edge and clear_edges. Frees edge structure
+ without actually unlinking it from the pred/succ lists. */
-/* True if a given label can be deleted. */
-
-static int
-can_delete_label_p (label)
- rtx label;
-{
- rtx x;
-
- if (LABEL_PRESERVE_P (label))
- return 0;
-
- for (x = forced_labels; x; x = XEXP (x, 1))
- if (label == XEXP (x, 0))
- return 0;
- for (x = label_value_list; x; x = XEXP (x, 1))
- if (label == XEXP (x, 0))
- return 0;
- for (x = exception_handler_labels; x; x = XEXP (x, 1))
- if (label == XEXP (x, 0))
- return 0;
-
- /* User declared labels must be preserved. */
- if (LABEL_NAME (label) != 0)
- return 0;
-
- return 1;
-}
-
-/* Delete INSN by patching it out. Return the next insn. */
-
-rtx
-delete_insn (insn)
- rtx insn;
+static void
+free_edge (edge e)
{
- rtx next = NEXT_INSN (insn);
- rtx note;
- bool really_delete = true;
-
- if (GET_CODE (insn) == CODE_LABEL)
- {
- /* Some labels can't be directly removed from the INSN chain, as they
- might be references via variables, constant pool etc.
- Convert them to the special NOTE_INSN_DELETED_LABEL note. */
- if (! can_delete_label_p (insn))
- {
- const char *name = LABEL_NAME (insn);
-
- really_delete = false;
- PUT_CODE (insn, NOTE);
- NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL;
- NOTE_SOURCE_FILE (insn) = name;
- }
- remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels);
- }
-
- if (really_delete)
- {
- remove_insn (insn);
- INSN_DELETED_P (insn) = 1;
- }
-
- /* If deleting a jump, decrement the use count of the label. Deleting
- the label itself should happen in the normal course of block merging. */
- if (GET_CODE (insn) == JUMP_INSN
- && JUMP_LABEL (insn)
- && GET_CODE (JUMP_LABEL (insn)) == CODE_LABEL)
- LABEL_NUSES (JUMP_LABEL (insn))--;
-
- /* Also if deleting an insn that references a label. */
- else if ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX
- && GET_CODE (XEXP (note, 0)) == CODE_LABEL)
- LABEL_NUSES (XEXP (note, 0))--;
-
- if (GET_CODE (insn) == JUMP_INSN
- && (GET_CODE (PATTERN (insn)) == ADDR_VEC
- || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC))
- {
- rtx pat = PATTERN (insn);
- int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC;
- int len = XVECLEN (pat, diff_vec_p);
- int i;
-
- for (i = 0; i < len; i++)
- LABEL_NUSES (XEXP (XVECEXP (pat, diff_vec_p, i), 0))--;
- }
-
- return next;
+ n_edges--;
+ pool_free (edge_pool, e);
}
-/* Unlink a chain of insns between START and FINISH, leaving notes
- that must be paired. */
+/* Free the memory associated with the edge structures. */
void
-delete_insn_chain (start, finish)
- rtx start, finish;
-{
- /* Unchain the insns one by one. It would be quicker to delete all
- of these with a single unchaining, rather than one at a time, but
- we need to keep the NOTE's. */
-
- rtx next;
-
- while (1)
- {
- next = NEXT_INSN (start);
- if (GET_CODE (start) == NOTE && !can_delete_note_p (start))
- ;
- else
- next = delete_insn (start);
-
- if (start == finish)
- break;
- start = next;
- }
-}
-\f
-/* Create a new basic block consisting of the instructions between
- HEAD and END inclusive. This function is designed to allow fast
- BB construction - reuses the note and basic block struct
- in BB_NOTE, if any and do not grow BASIC_BLOCK chain and should
- be used directly only by CFG construction code.
- END can be NULL in to create new empty basic block before HEAD.
- Both END and HEAD can be NULL to create basic block at the end of
- INSN chain. */
-
-basic_block
-create_basic_block_structure (index, head, end, bb_note)
- int index;
- rtx head, end, bb_note;
+clear_edges (void)
{
basic_block bb;
+ edge e;
- if (bb_note
- && ! RTX_INTEGRATED_P (bb_note)
- && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL
- && bb->aux == NULL)
+ FOR_EACH_BB (bb)
{
- /* If we found an existing note, thread it back onto the chain. */
+ edge e = bb->succ;
- rtx after;
-
- if (GET_CODE (head) == CODE_LABEL)
- after = head;
- else
+ while (e)
{
- after = PREV_INSN (head);
- head = bb_note;
+ edge next = e->succ_next;
+
+ free_edge (e);
+ e = next;
}
- if (after != bb_note && NEXT_INSN (after) != bb_note)
- reorder_insns (bb_note, bb_note, after);
+ bb->succ = NULL;
+ bb->pred = NULL;
}
- else
- {
- /* Otherwise we must create a note and a basic block structure.
- Since we allow basic block structs in rtl, give the struct
- the same lifetime by allocating it off the function obstack
- rather than using malloc. */
- bb = (basic_block) obstack_alloc (&flow_obstack, sizeof (*bb));
- memset (bb, 0, sizeof (*bb));
+ e = ENTRY_BLOCK_PTR->succ;
+ while (e)
+ {
+ edge next = e->succ_next;
- if (!head && !end)
- {
- head = end = bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK,
- get_last_insn ());
- }
- else if (GET_CODE (head) == CODE_LABEL && end)
- {
- bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head);
- if (head == end)
- end = bb_note;
- }
- else
- {
- bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head);
- head = bb_note;
- if (!end)
- end = head;
- }
- NOTE_BASIC_BLOCK (bb_note) = bb;
+ free_edge (e);
+ e = next;
}
- /* Always include the bb note in the block. */
- if (NEXT_INSN (end) == bb_note)
- end = bb_note;
-
- bb->head = head;
- bb->end = end;
- bb->index = index;
- BASIC_BLOCK (index) = bb;
- if (basic_block_for_insn)
- update_bb_for_insn (bb);
-
- /* Tag the block so that we know it has been used when considering
- other basic block notes. */
- bb->aux = bb;
+ EXIT_BLOCK_PTR->pred = NULL;
+ ENTRY_BLOCK_PTR->succ = NULL;
- return bb;
+ if (n_edges)
+ abort ();
}
-
-/* Create new basic block consisting of instructions in between HEAD and
- END and place it to the BB chain at possition INDEX.
- END can be NULL in to create new empty basic block before HEAD.
- Both END and HEAD can be NULL to create basic block at the end of
- INSN chain. */
+\f
+/* Allocate memory for basic_block. */
basic_block
-create_basic_block (index, head, end)
- int index;
- rtx head, end;
+alloc_block (void)
{
basic_block bb;
- int i;
-
- /* Place the new block just after the block being split. */
- VARRAY_GROW (basic_block_info, ++n_basic_blocks);
-
- /* Some parts of the compiler expect blocks to be number in
- sequential order so insert the new block immediately after the
- block being split.. */
- for (i = n_basic_blocks - 1; i > index; --i)
- {
- basic_block tmp = BASIC_BLOCK (i - 1);
- BASIC_BLOCK (i) = tmp;
- tmp->index = i;
- }
-
- bb = create_basic_block_structure (index, head, end, NULL);
- bb->aux = NULL;
+ bb = pool_alloc (bb_pool);
+ memset (bb, 0, sizeof (*bb));
return bb;
}
-/* Remove block B from the basic block array and compact behind it. */
-
+/* Link block B to chain after AFTER. */
void
-expunge_block (b)
- basic_block b;
+link_block (basic_block b, basic_block after)
{
- int i, n = n_basic_blocks;
-
- for (i = b->index; i + 1 < n; ++i)
- {
- basic_block x = BASIC_BLOCK (i + 1);
- BASIC_BLOCK (i) = x;
- x->index = i;
- }
-
- /* Invalidate data to make bughunting easier. */
- memset (b, 0, sizeof (*b));
- b->index = -3;
- basic_block_info->num_elements--;
- n_basic_blocks--;
+ b->next_bb = after->next_bb;
+ b->prev_bb = after;
+ after->next_bb = b;
+ b->next_bb->prev_bb = b;
}
-/* Delete the insns in a (non-live) block. We physically delete every
- non-deleted-note insn, and update the flow graph appropriately.
-
- Return nonzero if we deleted an exception handler. */
-
-/* ??? Preserving all such notes strikes me as wrong. It would be nice
- to post-process the stream to remove empty blocks, loops, ranges, etc. */
-
-int
-flow_delete_block (b)
- basic_block b;
+/* Unlink block B from chain. */
+void
+unlink_block (basic_block b)
{
- int deleted_handler = 0;
- rtx insn, end, tmp;
-
- /* If the head of this block is a CODE_LABEL, then it might be the
- label for an exception handler which can't be reached.
-
- We need to remove the label from the exception_handler_label list
- and remove the associated NOTE_INSN_EH_REGION_BEG and
- NOTE_INSN_EH_REGION_END notes. */
-
- insn = b->head;
-
- never_reached_warning (insn);
-
- if (GET_CODE (insn) == CODE_LABEL)
- maybe_remove_eh_handler (insn);
-
- /* Include any jump table following the basic block. */
- end = b->end;
- if (GET_CODE (end) == JUMP_INSN
- && (tmp = JUMP_LABEL (end)) != NULL_RTX
- && (tmp = NEXT_INSN (tmp)) != NULL_RTX
- && GET_CODE (tmp) == JUMP_INSN
- && (GET_CODE (PATTERN (tmp)) == ADDR_VEC
- || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC))
- end = tmp;
-
- /* Include any barrier that may follow the basic block. */
- tmp = next_nonnote_insn (end);
- if (tmp && GET_CODE (tmp) == BARRIER)
- end = tmp;
-
- /* Selectively delete the entire chain. */
- b->head = NULL;
- delete_insn_chain (insn, end);
-
- /* Remove the edges into and out of this block. Note that there may
- indeed be edges in, if we are removing an unreachable loop. */
- while (b->pred != NULL)
- remove_edge (b->pred);
- while (b->succ != NULL)
- remove_edge (b->succ);
-
- b->pred = NULL;
- b->succ = NULL;
-
- /* Remove the basic block from the array, and compact behind it. */
- expunge_block (b);
-
- return deleted_handler;
+ b->next_bb->prev_bb = b->prev_bb;
+ b->prev_bb->next_bb = b->next_bb;
}
-\f
-/* Records the basic block struct in BB_FOR_INSN, for every instruction
- indexed by INSN_UID. MAX is the size of the array. */
+/* Sequentially order blocks and compact the arrays. */
void
-compute_bb_for_insn (max)
- int max;
+compact_blocks (void)
{
int i;
+ basic_block bb;
- if (basic_block_for_insn)
- VARRAY_FREE (basic_block_for_insn);
- VARRAY_BB_INIT (basic_block_for_insn, max, "basic_block_for_insn");
-
- for (i = 0; i < n_basic_blocks; ++i)
+ i = 0;
+ FOR_EACH_BB (bb)
{
- basic_block bb = BASIC_BLOCK (i);
- rtx insn, end;
-
- end = bb->end;
- insn = bb->head;
- while (1)
- {
- int uid = INSN_UID (insn);
- if (uid < max)
- VARRAY_BB (basic_block_for_insn, uid) = bb;
- if (insn == end)
- break;
- insn = NEXT_INSN (insn);
- }
+ BASIC_BLOCK (i) = bb;
+ bb->index = i;
+ i++;
}
-}
-/* Release the basic_block_for_insn array. */
+ if (i != n_basic_blocks)
+ abort ();
-void
-free_bb_for_insn ()
-{
- if (basic_block_for_insn)
- VARRAY_FREE (basic_block_for_insn);
- basic_block_for_insn = 0;
+ last_basic_block = n_basic_blocks;
}
-/* Update insns block within BB. */
+/* Remove block B from the basic block array. */
void
-update_bb_for_insn (bb)
- basic_block bb;
+expunge_block (basic_block b)
{
- rtx insn;
-
- if (! basic_block_for_insn)
- return;
-
- for (insn = bb->head; ; insn = NEXT_INSN (insn))
- {
- set_block_for_insn (insn, bb);
-
- if (insn == bb->end)
- break;
- }
+ unlink_block (b);
+ BASIC_BLOCK (b->index) = NULL;
+ n_basic_blocks--;
+ pool_free (bb_pool, b);
}
+\f
+/* Create an edge connecting SRC and DEST with flags FLAGS. Return newly
+ created edge. Use this only if you are sure that this edge can't
+ possibly already exist. */
-/* Record INSN's block as BB. */
-
-void
-set_block_for_insn (insn, bb)
- rtx insn;
- basic_block bb;
+edge
+unchecked_make_edge (basic_block src, basic_block dst, int flags)
{
- size_t uid = INSN_UID (insn);
- if (uid >= basic_block_for_insn->num_elements)
- {
- int new_size;
-
- /* Add one-eighth the size so we don't keep calling xrealloc. */
- new_size = uid + (uid + 7) / 8;
-
- VARRAY_GROW (basic_block_for_insn, new_size);
- }
- VARRAY_BB (basic_block_for_insn, uid) = bb;
-}
+ edge e;
+ e = pool_alloc (edge_pool);
+ memset (e, 0, sizeof (*e));
+ n_edges++;
-/* When a new insn has been inserted into an existing block, it will
- sometimes emit more than a single insn. This routine will set the
- block number for the specified insn, and look backwards in the insn
- chain to see if there are any other uninitialized insns immediately
- previous to this one, and set the block number for them too. */
+ e->succ_next = src->succ;
+ e->pred_next = dst->pred;
+ e->src = src;
+ e->dest = dst;
+ e->flags = flags;
-void
-set_block_for_new_insns (insn, bb)
- rtx insn;
- basic_block bb;
-{
- set_block_for_insn (insn, bb);
+ src->succ = e;
+ dst->pred = e;
- /* Scan the previous instructions setting the block number until we find
- an instruction that has the block number set, or we find a note
- of any kind. */
- for (insn = PREV_INSN (insn); insn != NULL_RTX; insn = PREV_INSN (insn))
- {
- if (GET_CODE (insn) == NOTE)
- break;
- if ((unsigned) INSN_UID (insn) >= basic_block_for_insn->num_elements
- || BLOCK_FOR_INSN (insn) == 0)
- set_block_for_insn (insn, bb);
- else
- break;
- }
+ return e;
}
-\f
+
/* Create an edge connecting SRC and DST with FLAGS optionally using
- edge cache CACHE. Return the new edge, NULL if already exist. */
+ edge cache CACHE. Return the new edge, NULL if already exist. */
edge
-cached_make_edge (edge_cache, src, dst, flags)
- sbitmap *edge_cache;
- basic_block src, dst;
- int flags;
+cached_make_edge (sbitmap *edge_cache, basic_block src, basic_block dst, int flags)
{
int use_edge_cache;
edge e;
- /* Don't bother with edge cache for ENTRY or EXIT; there aren't that
- many edges to them, and we didn't allocate memory for it. */
+ /* Don't bother with edge cache for ENTRY or EXIT, if there aren't that
+ many edges to them, or we didn't allocate memory for it. */
use_edge_cache = (edge_cache
- && src != ENTRY_BLOCK_PTR
- && dst != EXIT_BLOCK_PTR);
+ && src != ENTRY_BLOCK_PTR && dst != EXIT_BLOCK_PTR);
/* Make sure we don't add duplicate edges. */
switch (use_edge_cache)
{
default:
- /* Quick test for non-existance of the edge. */
+ /* Quick test for non-existence of the edge. */
if (! TEST_BIT (edge_cache[src->index], dst->index))
break;
if (flags == 0)
return NULL;
- /* FALLTHRU */
+ /* Fall through. */
case 0:
for (e = src->succ; e; e = e->succ_next)
if (e->dest == dst)
break;
}
- if (first_deleted_edge)
- {
- e = first_deleted_edge;
- first_deleted_edge = e->succ_next;
- }
- else
- {
- e = (edge) obstack_alloc (&flow_obstack, sizeof (*e));
- memset (e, 0, sizeof (*e));
- }
- n_edges++;
-
- e->succ_next = src->succ;
- e->pred_next = dst->pred;
- e->src = src;
- e->dest = dst;
- e->flags = flags;
-
- src->succ = e;
- dst->pred = e;
+ e = unchecked_make_edge (src, dst, flags);
if (use_edge_cache)
SET_BIT (edge_cache[src->index], dst->index);
created edge or NULL if already exist. */
edge
-make_edge (src, dest, flags)
- basic_block src, dest;
- int flags;
+make_edge (basic_block src, basic_block dest, int flags)
{
return cached_make_edge (NULL, src, dest, flags);
}
-/* Create an edge connecting SRC to DEST and set probability by knowling
+/* Create an edge connecting SRC to DEST and set probability by knowing
that it is the single edge leaving SRC. */
edge
-make_single_succ_edge (src, dest, flags)
- basic_block src, dest;
- int flags;
+make_single_succ_edge (basic_block src, basic_block dest, int flags)
{
edge e = make_edge (src, dest, flags);
/* This function will remove an edge from the flow graph. */
void
-remove_edge (e)
- edge e;
+remove_edge (edge e)
{
edge last_pred = NULL;
edge last_succ = NULL;
edge tmp;
basic_block src, dest;
+
src = e->src;
dest = e->dest;
for (tmp = src->succ; tmp && tmp != e; tmp = tmp->succ_next)
else
dest->pred = e->pred_next;
- n_edges--;
- memset (e, 0, sizeof (*e));
- e->succ_next = first_deleted_edge;
- first_deleted_edge = e;
+ free_edge (e);
}
/* Redirect an edge's successor from one block to another. */
void
-redirect_edge_succ (e, new_succ)
- edge e;
- basic_block new_succ;
+redirect_edge_succ (edge e, basic_block new_succ)
{
edge *pe;
e->dest = new_succ;
}
-/* Like previous but avoid possible dupplicate edge. */
+/* Like previous but avoid possible duplicate edge. */
edge
-redirect_edge_succ_nodup (e, new_succ)
- edge e;
- basic_block new_succ;
+redirect_edge_succ_nodup (edge e, basic_block new_succ)
{
edge s;
+
/* Check whether the edge is already present. */
for (s = e->src->succ; s; s = s->succ_next)
if (s->dest == new_succ && s != e)
break;
+
if (s)
{
s->flags |= e->flags;
s->probability += e->probability;
+ if (s->probability > REG_BR_PROB_BASE)
+ s->probability = REG_BR_PROB_BASE;
s->count += e->count;
remove_edge (e);
e = s;
}
else
redirect_edge_succ (e, new_succ);
+
return e;
}
/* Redirect an edge's predecessor from one block to another. */
void
-redirect_edge_pred (e, new_pred)
- edge e;
- basic_block new_pred;
+redirect_edge_pred (edge e, basic_block new_pred)
{
edge *pe;
/* Disconnect the edge from the old predecessor block. */
for (pe = &e->src->succ; *pe != e; pe = &(*pe)->succ_next)
continue;
+
*pe = (*pe)->succ_next;
/* Reconnect the edge to the new predecessor block. */
new_pred->succ = e;
e->src = new_pred;
}
-\f
-/* Split a block BB after insn INSN creating a new fallthru edge.
- Return the new edge. Note that to keep other parts of the compiler happy,
- this function renumbers all the basic blocks so that the new
- one has a number one greater than the block split. */
-edge
-split_block (bb, insn)
- basic_block bb;
- rtx insn;
+void
+clear_bb_flags (void)
{
- basic_block new_bb;
- edge new_edge;
- edge e;
-
- /* There is no point splitting the block after its end. */
- if (bb->end == insn)
- return 0;
-
- /* Create the new basic block. */
- new_bb = create_basic_block (bb->index + 1, NEXT_INSN (insn), bb->end);
- new_bb->count = bb->count;
- new_bb->frequency = bb->frequency;
- new_bb->loop_depth = bb->loop_depth;
- bb->end = insn;
-
- /* Redirect the outgoing edges. */
- new_bb->succ = bb->succ;
- bb->succ = NULL;
- for (e = new_bb->succ; e; e = e->succ_next)
- e->src = new_bb;
-
- new_edge = make_single_succ_edge (bb, new_bb, EDGE_FALLTHRU);
-
- if (bb->global_live_at_start)
- {
- new_bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack);
- new_bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack);
- COPY_REG_SET (new_bb->global_live_at_end, bb->global_live_at_end);
-
- /* We now have to calculate which registers are live at the end
- of the split basic block and at the start of the new basic
- block. Start with those registers that are known to be live
- at the end of the original basic block and get
- propagate_block to determine which registers are live. */
- COPY_REG_SET (new_bb->global_live_at_start, bb->global_live_at_end);
- propagate_block (new_bb, new_bb->global_live_at_start, NULL, NULL, 0);
- COPY_REG_SET (bb->global_live_at_end,
- new_bb->global_live_at_start);
- }
+ basic_block bb;
- return new_edge;
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
+ bb->flags = 0;
}
-
-/* Blocks A and B are to be merged into a single block A. The insns
- are already contiguous, hence `nomove'. */
-
+\f
void
-merge_blocks_nomove (a, b)
- basic_block a, b;
+dump_flow_info (FILE *file)
{
- edge e;
- rtx b_head, b_end, a_end;
- rtx del_first = NULL_RTX, del_last = NULL_RTX;
- int b_empty = 0;
-
- /* If there was a CODE_LABEL beginning B, delete it. */
- b_head = b->head;
- b_end = b->end;
- if (GET_CODE (b_head) == CODE_LABEL)
- {
- /* Detect basic blocks with nothing but a label. This can happen
- in particular at the end of a function. */
- if (b_head == b_end)
- b_empty = 1;
- del_first = del_last = b_head;
- b_head = NEXT_INSN (b_head);
- }
-
- /* Delete the basic block note. */
- if (NOTE_INSN_BASIC_BLOCK_P (b_head))
- {
- if (b_head == b_end)
- b_empty = 1;
- if (! del_last)
- del_first = b_head;
- del_last = b_head;
- b_head = NEXT_INSN (b_head);
- }
-
- /* If there was a jump out of A, delete it. */
- a_end = a->end;
- if (GET_CODE (a_end) == JUMP_INSN)
- {
- rtx prev;
-
- for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev))
- if (GET_CODE (prev) != NOTE
- || NOTE_LINE_NUMBER (prev) == NOTE_INSN_BASIC_BLOCK
- || prev == a->head)
- break;
-
- del_first = a_end;
+ int i;
+ int max_regno = max_reg_num ();
+ basic_block bb;
+ static const char * const reg_class_names[] = REG_CLASS_NAMES;
-#ifdef HAVE_cc0
- /* If this was a conditional jump, we need to also delete
- the insn that set cc0. */
- if (only_sets_cc0_p (prev))
+ fprintf (file, "%d registers.\n", max_regno);
+ if (reg_n_info)
+ for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
+ if (REG_N_REFS (i))
{
- rtx tmp = prev;
- prev = prev_nonnote_insn (prev);
- if (!prev)
- prev = a->head;
- del_first = tmp;
+ enum reg_class class, altclass;
+
+ fprintf (file, "\nRegister %d used %d times across %d insns",
+ i, REG_N_REFS (i), REG_LIVE_LENGTH (i));
+ if (REG_BASIC_BLOCK (i) >= 0)
+ fprintf (file, " in block %d", REG_BASIC_BLOCK (i));
+ if (REG_N_SETS (i))
+ fprintf (file, "; set %d time%s", REG_N_SETS (i),
+ (REG_N_SETS (i) == 1) ? "" : "s");
+ if (regno_reg_rtx[i] != NULL && REG_USERVAR_P (regno_reg_rtx[i]))
+ fprintf (file, "; user var");
+ if (REG_N_DEATHS (i) != 1)
+ fprintf (file, "; dies in %d places", REG_N_DEATHS (i));
+ if (REG_N_CALLS_CROSSED (i) == 1)
+ fprintf (file, "; crosses 1 call");
+ else if (REG_N_CALLS_CROSSED (i))
+ fprintf (file, "; crosses %d calls", REG_N_CALLS_CROSSED (i));
+ if (regno_reg_rtx[i] != NULL
+ && PSEUDO_REGNO_BYTES (i) != UNITS_PER_WORD)
+ fprintf (file, "; %d bytes", PSEUDO_REGNO_BYTES (i));
+
+ class = reg_preferred_class (i);
+ altclass = reg_alternate_class (i);
+ if (class != GENERAL_REGS || altclass != ALL_REGS)
+ {
+ if (altclass == ALL_REGS || class == ALL_REGS)
+ fprintf (file, "; pref %s", reg_class_names[(int) class]);
+ else if (altclass == NO_REGS)
+ fprintf (file, "; %s or none", reg_class_names[(int) class]);
+ else
+ fprintf (file, "; pref %s, else %s",
+ reg_class_names[(int) class],
+ reg_class_names[(int) altclass]);
+ }
+
+ if (regno_reg_rtx[i] != NULL && REG_POINTER (regno_reg_rtx[i]))
+ fprintf (file, "; pointer");
+ fprintf (file, ".\n");
}
-#endif
- a_end = PREV_INSN (del_first);
- }
- else if (GET_CODE (NEXT_INSN (a_end)) == BARRIER)
- del_first = NEXT_INSN (a_end);
+ fprintf (file, "\n%d basic blocks, %d edges.\n", n_basic_blocks, n_edges);
+ FOR_EACH_BB (bb)
+ {
+ edge e;
+ int sum;
+ gcov_type lsum;
+
+ fprintf (file, "\nBasic block %d: first insn %d, last %d, ",
+ bb->index, INSN_UID (BB_HEAD (bb)), INSN_UID (BB_END (bb)));
+ fprintf (file, "prev %d, next %d, ",
+ bb->prev_bb->index, bb->next_bb->index);
+ fprintf (file, "loop_depth %d, count ", bb->loop_depth);
+ fprintf (file, HOST_WIDEST_INT_PRINT_DEC, bb->count);
+ fprintf (file, ", freq %i", bb->frequency);
+ if (maybe_hot_bb_p (bb))
+ fprintf (file, ", maybe hot");
+ if (probably_never_executed_bb_p (bb))
+ fprintf (file, ", probably never executed");
+ fprintf (file, ".\n");
- /* Normally there should only be one successor of A and that is B, but
- partway though the merge of blocks for conditional_execution we'll
- be merging a TEST block with THEN and ELSE successors. Free the
- whole lot of them and hope the caller knows what they're doing. */
- while (a->succ)
- remove_edge (a->succ);
+ fprintf (file, "Predecessors: ");
+ for (e = bb->pred; e; e = e->pred_next)
+ dump_edge_info (file, e, 0);
- /* Adjust the edges out of B for the new owner. */
- for (e = b->succ; e; e = e->succ_next)
- e->src = a;
- a->succ = b->succ;
+ fprintf (file, "\nSuccessors: ");
+ for (e = bb->succ; e; e = e->succ_next)
+ dump_edge_info (file, e, 1);
- /* B hasn't quite yet ceased to exist. Attempt to prevent mishap. */
- b->pred = b->succ = NULL;
+ fprintf (file, "\nRegisters live at start:");
+ dump_regset (bb->global_live_at_start, file);
- expunge_block (b);
+ fprintf (file, "\nRegisters live at end:");
+ dump_regset (bb->global_live_at_end, file);
- /* Delete everything marked above as well as crap that might be
- hanging out between the two blocks. */
- delete_insn_chain (del_first, del_last);
+ putc ('\n', file);
- /* Reassociate the insns of B with A. */
- if (!b_empty)
- {
- rtx x = a_end;
- if (basic_block_for_insn)
- {
- BLOCK_FOR_INSN (x) = a;
- while (x != b_end)
- {
- x = NEXT_INSN (x);
- BLOCK_FOR_INSN (x) = a;
- }
- }
- a_end = b_end;
+ /* Check the consistency of profile information. We can't do that
+ in verify_flow_info, as the counts may get invalid for incompletely
+ solved graphs, later eliminating of conditionals or roundoff errors.
+ It is still practical to have them reported for debugging of simple
+ testcases. */
+ sum = 0;
+ for (e = bb->succ; e; e = e->succ_next)
+ sum += e->probability;
+ if (bb->succ && abs (sum - REG_BR_PROB_BASE) > 100)
+ fprintf (file, "Invalid sum of outgoing probabilities %.1f%%\n",
+ sum * 100.0 / REG_BR_PROB_BASE);
+ sum = 0;
+ for (e = bb->pred; e; e = e->pred_next)
+ sum += EDGE_FREQUENCY (e);
+ if (abs (sum - bb->frequency) > 100)
+ fprintf (file,
+ "Invalid sum of incomming frequencies %i, should be %i\n",
+ sum, bb->frequency);
+ lsum = 0;
+ for (e = bb->pred; e; e = e->pred_next)
+ lsum += e->count;
+ if (lsum - bb->count > 100 || lsum - bb->count < -100)
+ fprintf (file, "Invalid sum of incomming counts %i, should be %i\n",
+ (int)lsum, (int)bb->count);
+ lsum = 0;
+ for (e = bb->succ; e; e = e->succ_next)
+ lsum += e->count;
+ if (bb->succ && (lsum - bb->count > 100 || lsum - bb->count < -100))
+ fprintf (file, "Invalid sum of incomming counts %i, should be %i\n",
+ (int)lsum, (int)bb->count);
}
- a->end = a_end;
+
+ putc ('\n', file);
}
-\f
-/* Return label in the head of basic block. Create one if it doesn't exist. */
-rtx
-block_label (block)
- basic_block block;
+void
+debug_flow_info (void)
{
- if (block == EXIT_BLOCK_PTR)
- return NULL_RTX;
- if (GET_CODE (block->head) != CODE_LABEL)
- {
- block->head = emit_label_before (gen_label_rtx (), block->head);
- if (basic_block_for_insn)
- set_block_for_insn (block->head, block);
- }
- return block->head;
+ dump_flow_info (stderr);
}
-/* Attempt to perform edge redirection by replacing possibly complex jump
- instruction by unconditional jump or removing jump completely.
- This can apply only if all edges now point to the same block.
-
- The parameters and return values are equivalent to redirect_edge_and_branch.
- */
-
-static bool
-try_redirect_by_replacing_jump (e, target)
- edge e;
- basic_block target;
+void
+dump_edge_info (FILE *file, edge e, int do_succ)
{
- basic_block src = e->src;
- rtx insn = src->end, kill_from;
- edge tmp;
- rtx set;
- int fallthru = 0;
-
- /* Verify that all targets will be TARGET. */
- for (tmp = src->succ; tmp; tmp = tmp->succ_next)
- if (tmp->dest != target && tmp != e)
- break;
- if (tmp || !onlyjump_p (insn))
- return false;
-
- /* Avoid removing branch with side effects. */
- set = single_set (insn);
- if (!set || side_effects_p (set))
- return false;
-
- /* In case we zap a conditional jump, we'll need to kill
- the cc0 setter too. */
- kill_from = insn;
-#ifdef HAVE_cc0
- if (reg_mentioned_p (cc0_rtx, PATTERN (insn)))
- kill_from = PREV_INSN (insn);
-#endif
-
- /* See if we can create the fallthru edge. */
- if (can_fallthru (src, target))
- {
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Removing jump %i.\n", INSN_UID (insn));
- fallthru = 1;
-
- /* Selectivly unlink whole insn chain. */
- delete_insn_chain (kill_from, PREV_INSN (target->head));
- }
- /* If this already is simplejump, redirect it. */
- else if (simplejump_p (insn))
- {
- if (e->dest == target)
- return false;
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Redirecting jump %i from %i to %i.\n",
- INSN_UID (insn), e->dest->index, target->index);
- redirect_jump (insn, block_label (target), 0);
- }
- /* Or replace possibly complicated jump insn by simple jump insn. */
- else
- {
- rtx target_label = block_label (target);
- rtx barrier;
-
- emit_jump_insn_after (gen_jump (target_label), kill_from);
- JUMP_LABEL (src->end) = target_label;
- LABEL_NUSES (target_label)++;
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Replacing insn %i by jump %i\n",
- INSN_UID (insn), INSN_UID (src->end));
-
- delete_insn_chain (kill_from, insn);
-
- barrier = next_nonnote_insn (src->end);
- if (!barrier || GET_CODE (barrier) != BARRIER)
- emit_barrier_after (src->end);
- }
-
- /* Keep only one edge out and set proper flags. */
- while (src->succ->succ_next)
- remove_edge (src->succ);
- e = src->succ;
- if (fallthru)
- e->flags = EDGE_FALLTHRU;
- else
- e->flags = 0;
- e->probability = REG_BR_PROB_BASE;
- e->count = src->count;
-
- /* We don't want a block to end on a line-number note since that has
- the potential of changing the code between -g and not -g. */
- while (GET_CODE (e->src->end) == NOTE
- && NOTE_LINE_NUMBER (e->src->end) >= 0)
- delete_insn (e->src->end);
-
- if (e->dest != target)
- redirect_edge_succ (e, target);
- return true;
-}
-
-/* Return last loop_beg note appearing after INSN, before start of next
- basic block. Return INSN if there are no such notes.
-
- When emmiting jump to redirect an fallthru edge, it should always
- appear after the LOOP_BEG notes, as loop optimizer expect loop to
- eighter start by fallthru edge or jump following the LOOP_BEG note
- jumping to the loop exit test. */
-
-static rtx
-last_loop_beg_note (insn)
- rtx insn;
-{
- rtx last = insn;
- insn = NEXT_INSN (insn);
- while (insn && GET_CODE (insn) == NOTE
- && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK)
- {
- if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
- last = insn;
- insn = NEXT_INSN (insn);
- }
- return last;
-}
-
-/* Attempt to change code to redirect edge E to TARGET.
- Don't do that on expense of adding new instructions or reordering
- basic blocks.
-
- Function can be also called with edge destionation equivalent to the
- TARGET. Then it should try the simplifications and do nothing if
- none is possible.
-
- Return true if transformation suceeded. We still return flase in case
- E already destinated TARGET and we didn't managed to simplify instruction
- stream. */
-
-bool
-redirect_edge_and_branch (e, target)
- edge e;
- basic_block target;
-{
- rtx tmp;
- rtx old_label = e->dest->head;
- basic_block src = e->src;
- rtx insn = src->end;
-
- if (e->flags & EDGE_COMPLEX)
- return false;
-
- if (try_redirect_by_replacing_jump (e, target))
- return true;
- /* Do this fast path late, as we want above code to simplify for cases
- where called on single edge leaving basic block containing nontrivial
- jump insn. */
- else if (e->dest == target)
- return false;
-
- /* We can only redirect non-fallthru edges of jump insn. */
- if (e->flags & EDGE_FALLTHRU)
- return false;
- if (GET_CODE (insn) != JUMP_INSN)
- return false;
-
- /* Recognize a tablejump and adjust all matching cases. */
- if ((tmp = JUMP_LABEL (insn)) != NULL_RTX
- && (tmp = NEXT_INSN (tmp)) != NULL_RTX
- && GET_CODE (tmp) == JUMP_INSN
- && (GET_CODE (PATTERN (tmp)) == ADDR_VEC
- || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC))
- {
- rtvec vec;
- int j;
- rtx new_label = block_label (target);
-
- if (GET_CODE (PATTERN (tmp)) == ADDR_VEC)
- vec = XVEC (PATTERN (tmp), 0);
- else
- vec = XVEC (PATTERN (tmp), 1);
-
- for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j)
- if (XEXP (RTVEC_ELT (vec, j), 0) == old_label)
- {
- RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label);
- --LABEL_NUSES (old_label);
- ++LABEL_NUSES (new_label);
- }
-
- /* Handle casesi dispatch insns */
- if ((tmp = single_set (insn)) != NULL
- && SET_DEST (tmp) == pc_rtx
- && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE
- && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF
- && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label)
- {
- XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (VOIDmode,
- new_label);
- --LABEL_NUSES (old_label);
- ++LABEL_NUSES (new_label);
- }
- }
- else
- {
- /* ?? We may play the games with moving the named labels from
- one basic block to the other in case only one computed_jump is
- available. */
- if (computed_jump_p (insn))
- return false;
-
- /* A return instruction can't be redirected. */
- if (returnjump_p (insn))
- return false;
-
- /* If the insn doesn't go where we think, we're confused. */
- if (JUMP_LABEL (insn) != old_label)
- abort ();
- redirect_jump (insn, block_label (target), 0);
- }
-
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Edge %i->%i redirected to %i\n",
- e->src->index, e->dest->index, target->index);
- if (e->dest != target)
- redirect_edge_succ_nodup (e, target);
- return true;
-}
-
-/* Like force_nonfallthru bellow, but additionally performs redirection
- Used by redirect_edge_and_branch_force. */
-
-static basic_block
-force_nonfallthru_and_redirect (e, target)
- edge e;
- basic_block target;
-{
- basic_block jump_block, new_bb = NULL;
- rtx note;
- edge new_edge;
-
- if (e->flags & EDGE_ABNORMAL)
- abort ();
- if (!(e->flags & EDGE_FALLTHRU))
- abort ();
- if (e->src->succ->succ_next)
- {
- /* Create the new structures. */
- note = last_loop_beg_note (e->src->end);
- jump_block = create_basic_block (e->src->index + 1, NEXT_INSN (note), NULL);
- jump_block->count = e->count;
- jump_block->frequency = EDGE_FREQUENCY (e);
- jump_block->loop_depth = target->loop_depth;
-
- if (target->global_live_at_start)
- {
- jump_block->global_live_at_start =
- OBSTACK_ALLOC_REG_SET (&flow_obstack);
- jump_block->global_live_at_end =
- OBSTACK_ALLOC_REG_SET (&flow_obstack);
- COPY_REG_SET (jump_block->global_live_at_start,
- target->global_live_at_start);
- COPY_REG_SET (jump_block->global_live_at_end,
- target->global_live_at_start);
- }
-
- /* Wire edge in. */
- new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU);
- new_edge->probability = e->probability;
- new_edge->count = e->count;
-
- /* Redirect old edge. */
- redirect_edge_pred (e, jump_block);
- e->probability = REG_BR_PROB_BASE;
-
- new_bb = jump_block;
- }
- else
- jump_block = e->src;
- e->flags &= ~EDGE_FALLTHRU;
- if (target == EXIT_BLOCK_PTR)
- {
- if (HAVE_return)
- emit_jump_insn_after (gen_return (), jump_block->end);
- else
- abort ();
- }
- else
- {
- rtx label = block_label (target);
- emit_jump_insn_after (gen_jump (label), jump_block->end);
- JUMP_LABEL (jump_block->end) = label;
- LABEL_NUSES (label)++;
- }
- emit_barrier_after (jump_block->end);
- redirect_edge_succ_nodup (e, target);
-
- return new_bb;
-}
-
-/* Edge E is assumed to be fallthru edge. Emit needed jump instruction
- (and possibly create new basic block) to make edge non-fallthru.
- Return newly created BB or NULL if none. */
-basic_block
-force_nonfallthru (e)
- edge e;
-{
- return force_nonfallthru_and_redirect (e, e->dest);
-}
-
-/* Redirect edge even at the expense of creating new jump insn or
- basic block. Return new basic block if created, NULL otherwise.
- Abort if converison is impossible. */
-
-basic_block
-redirect_edge_and_branch_force (e, target)
- edge e;
- basic_block target;
-{
- basic_block new_bb;
-
- if (redirect_edge_and_branch (e, target))
- return NULL;
- if (e->dest == target)
- return NULL;
-
- /* In case the edge redirection failed, try to force it to be non-fallthru
- and redirect newly created simplejump. */
- new_bb = force_nonfallthru_and_redirect (e, target);
- return new_bb;
-}
-
-/* The given edge should potentially be a fallthru edge. If that is in
- fact true, delete the jump and barriers that are in the way. */
-
-void
-tidy_fallthru_edge (e, b, c)
- edge e;
- basic_block b, c;
-{
- rtx q;
-
- /* ??? In a late-running flow pass, other folks may have deleted basic
- blocks by nopping out blocks, leaving multiple BARRIERs between here
- and the target label. They ought to be chastized and fixed.
-
- We can also wind up with a sequence of undeletable labels between
- one block and the next.
-
- So search through a sequence of barriers, labels, and notes for
- the head of block C and assert that we really do fall through. */
-
- if (next_real_insn (b->end) != next_real_insn (PREV_INSN (c->head)))
- return;
-
- /* Remove what will soon cease being the jump insn from the source block.
- If block B consisted only of this single jump, turn it into a deleted
- note. */
- q = b->end;
- if (GET_CODE (q) == JUMP_INSN
- && onlyjump_p (q)
- && (any_uncondjump_p (q)
- || (b->succ == e && e->succ_next == NULL)))
- {
-#ifdef HAVE_cc0
- /* If this was a conditional jump, we need to also delete
- the insn that set cc0. */
- if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q)))
- q = PREV_INSN (q);
-#endif
-
- q = PREV_INSN (q);
-
- /* We don't want a block to end on a line-number note since that has
- the potential of changing the code between -g and not -g. */
- while (GET_CODE (q) == NOTE && NOTE_LINE_NUMBER (q) >= 0)
- q = PREV_INSN (q);
- }
-
- /* Selectively unlink the sequence. */
- if (q != PREV_INSN (c->head))
- delete_insn_chain (NEXT_INSN (q), PREV_INSN (c->head));
-
- e->flags |= EDGE_FALLTHRU;
-}
-
-/* Fix up edges that now fall through, or rather should now fall through
- but previously required a jump around now deleted blocks. Simplify
- the search by only examining blocks numerically adjacent, since this
- is how find_basic_blocks created them. */
-
-void
-tidy_fallthru_edges ()
-{
- int i;
-
- for (i = 1; i < n_basic_blocks; ++i)
- {
- basic_block b = BASIC_BLOCK (i - 1);
- basic_block c = BASIC_BLOCK (i);
- edge s;
-
- /* We care about simple conditional or unconditional jumps with
- a single successor.
-
- If we had a conditional branch to the next instruction when
- find_basic_blocks was called, then there will only be one
- out edge for the block which ended with the conditional
- branch (since we do not create duplicate edges).
-
- Furthermore, the edge will be marked as a fallthru because we
- merge the flags for the duplicate edges. So we do not want to
- check that the edge is not a FALLTHRU edge. */
- if ((s = b->succ) != NULL
- && ! (s->flags & EDGE_COMPLEX)
- && s->succ_next == NULL
- && s->dest == c
- /* If the jump insn has side effects, we can't tidy the edge. */
- && (GET_CODE (b->end) != JUMP_INSN
- || onlyjump_p (b->end)))
- tidy_fallthru_edge (s, b, c);
- }
-}
-\f
-/* Helper function for split_edge. Return true in case edge BB2 to BB1
- is back edge of syntactic loop. */
-
-static bool
-back_edge_of_syntactic_loop_p (bb1, bb2)
- basic_block bb1, bb2;
-{
- rtx insn;
- int count = 0;
-
- if (bb1->index > bb2->index)
- return false;
-
- if (bb1->index == bb2->index)
- return true;
-
- for (insn = bb1->end; insn != bb2->head && count >= 0;
- insn = NEXT_INSN (insn))
- if (GET_CODE (insn) == NOTE)
- {
- if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
- count++;
- if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END)
- count--;
- }
-
- return count >= 0;
-}
-
-/* Split a (typically critical) edge. Return the new block.
- Abort on abnormal edges.
-
- ??? The code generally expects to be called on critical edges.
- The case of a block ending in an unconditional jump to a
- block with multiple predecessors is not handled optimally. */
-
-basic_block
-split_edge (edge_in)
- edge edge_in;
-{
- basic_block bb;
- edge edge_out;
- rtx before;
-
- /* Abnormal edges cannot be split. */
- if ((edge_in->flags & EDGE_ABNORMAL) != 0)
- abort ();
-
- /* We are going to place the new block in front of edge destination.
- Avoid existence of fallthru predecesors. */
- if ((edge_in->flags & EDGE_FALLTHRU) == 0)
- {
- edge e;
- for (e = edge_in->dest->pred; e; e = e->pred_next)
- if (e->flags & EDGE_FALLTHRU)
- break;
-
- if (e)
- force_nonfallthru (e);
- }
-
- /* Create the basic block note.
-
- Where we place the note can have a noticable impact on the generated
- code. Consider this cfg:
-
- E
- |
- 0
- / \
- +->1-->2--->E
- | |
- +--+
-
- If we need to insert an insn on the edge from block 0 to block 1,
- we want to ensure the instructions we insert are outside of any
- loop notes that physically sit between block 0 and block 1. Otherwise
- we confuse the loop optimizer into thinking the loop is a phony. */
-
- if (edge_in->dest != EXIT_BLOCK_PTR
- && PREV_INSN (edge_in->dest->head)
- && GET_CODE (PREV_INSN (edge_in->dest->head)) == NOTE
- && NOTE_LINE_NUMBER (PREV_INSN (edge_in->dest->head)) == NOTE_INSN_LOOP_BEG
- && !back_edge_of_syntactic_loop_p (edge_in->dest, edge_in->src))
- before = PREV_INSN (edge_in->dest->head);
- else if (edge_in->dest != EXIT_BLOCK_PTR)
- before = edge_in->dest->head;
- else
- before = NULL_RTX;
-
- bb = create_basic_block (edge_in->dest == EXIT_BLOCK_PTR ? n_basic_blocks
- : edge_in->dest->index, before, NULL);
- bb->count = edge_in->count;
- bb->frequency = EDGE_FREQUENCY (edge_in);
-
- /* ??? This info is likely going to be out of date very soon. */
- if (edge_in->dest->global_live_at_start)
- {
- bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack);
- bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack);
- COPY_REG_SET (bb->global_live_at_start, edge_in->dest->global_live_at_start);
- COPY_REG_SET (bb->global_live_at_end, edge_in->dest->global_live_at_start);
- }
-
- edge_out = make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU);
-
- /* For non-fallthry edges, we must adjust the predecessor's
- jump instruction to target our new block. */
- if ((edge_in->flags & EDGE_FALLTHRU) == 0)
- {
- if (!redirect_edge_and_branch (edge_in, bb))
- abort ();
- }
- else
- redirect_edge_succ (edge_in, bb);
-
- return bb;
-}
-
-/* Queue instructions for insertion on an edge between two basic blocks.
- The new instructions and basic blocks (if any) will not appear in the
- CFG until commit_edge_insertions is called. */
-
-void
-insert_insn_on_edge (pattern, e)
- rtx pattern;
- edge e;
-{
- /* We cannot insert instructions on an abnormal critical edge.
- It will be easier to find the culprit if we die now. */
- if ((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e))
- abort ();
-
- if (e->insns == NULL_RTX)
- start_sequence ();
- else
- push_to_sequence (e->insns);
-
- emit_insn (pattern);
-
- e->insns = get_insns ();
- end_sequence ();
-}
-
-/* Update the CFG for the instructions queued on edge E. */
-
-static void
-commit_one_edge_insertion (e)
- edge e;
-{
- rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last;
- basic_block bb;
-
- /* Pull the insns off the edge now since the edge might go away. */
- insns = e->insns;
- e->insns = NULL_RTX;
-
- /* Figure out where to put these things. If the destination has
- one predecessor, insert there. Except for the exit block. */
- if (e->dest->pred->pred_next == NULL
- && e->dest != EXIT_BLOCK_PTR)
- {
- bb = e->dest;
-
- /* Get the location correct wrt a code label, and "nice" wrt
- a basic block note, and before everything else. */
- tmp = bb->head;
- if (GET_CODE (tmp) == CODE_LABEL)
- tmp = NEXT_INSN (tmp);
- if (NOTE_INSN_BASIC_BLOCK_P (tmp))
- tmp = NEXT_INSN (tmp);
- if (tmp == bb->head)
- before = tmp;
- else
- after = PREV_INSN (tmp);
- }
-
- /* If the source has one successor and the edge is not abnormal,
- insert there. Except for the entry block. */
- else if ((e->flags & EDGE_ABNORMAL) == 0
- && e->src->succ->succ_next == NULL
- && e->src != ENTRY_BLOCK_PTR)
- {
- bb = e->src;
- /* It is possible to have a non-simple jump here. Consider a target
- where some forms of unconditional jumps clobber a register. This
- happens on the fr30 for example.
-
- We know this block has a single successor, so we can just emit
- the queued insns before the jump. */
- if (GET_CODE (bb->end) == JUMP_INSN)
- {
- before = bb->end;
- while (GET_CODE (PREV_INSN (before)) == NOTE
- && NOTE_LINE_NUMBER (PREV_INSN (before)) == NOTE_INSN_LOOP_BEG)
- before = PREV_INSN (before);
- }
- else
- {
- /* We'd better be fallthru, or we've lost track of what's what. */
- if ((e->flags & EDGE_FALLTHRU) == 0)
- abort ();
-
- after = bb->end;
- }
- }
-
- /* Otherwise we must split the edge. */
- else
- {
- bb = split_edge (e);
- after = bb->end;
- }
-
- /* Now that we've found the spot, do the insertion. */
-
- if (before)
- {
- emit_insns_before (insns, before);
- last = prev_nonnote_insn (before);
- }
- else
- last = emit_insns_after (insns, after);
-
- if (returnjump_p (last))
- {
- /* ??? Remove all outgoing edges from BB and add one for EXIT.
- This is not currently a problem because this only happens
- for the (single) epilogue, which already has a fallthru edge
- to EXIT. */
-
- e = bb->succ;
- if (e->dest != EXIT_BLOCK_PTR
- || e->succ_next != NULL
- || (e->flags & EDGE_FALLTHRU) == 0)
- abort ();
- e->flags &= ~EDGE_FALLTHRU;
-
- emit_barrier_after (last);
-
- if (before)
- delete_insn (before);
- }
- else if (GET_CODE (last) == JUMP_INSN)
- abort ();
- find_sub_basic_blocks (bb);
-}
-
-/* Update the CFG for all queued instructions. */
-
-void
-commit_edge_insertions ()
-{
- int i;
- basic_block bb;
-
-#ifdef ENABLE_CHECKING
- verify_flow_info ();
-#endif
-
- i = -1;
- bb = ENTRY_BLOCK_PTR;
- while (1)
- {
- edge e, next;
-
- for (e = bb->succ; e; e = next)
- {
- next = e->succ_next;
- if (e->insns)
- commit_one_edge_insertion (e);
- }
-
- if (++i >= n_basic_blocks)
- break;
- bb = BASIC_BLOCK (i);
- }
-}
-\f
-void
-dump_flow_info (file)
- FILE *file;
-{
- register int i;
- static const char * const reg_class_names[] = REG_CLASS_NAMES;
-
- fprintf (file, "%d registers.\n", max_regno);
- for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
- if (REG_N_REFS (i))
- {
- enum reg_class class, altclass;
- fprintf (file, "\nRegister %d used %d times across %d insns",
- i, REG_N_REFS (i), REG_LIVE_LENGTH (i));
- if (REG_BASIC_BLOCK (i) >= 0)
- fprintf (file, " in block %d", REG_BASIC_BLOCK (i));
- if (REG_N_SETS (i))
- fprintf (file, "; set %d time%s", REG_N_SETS (i),
- (REG_N_SETS (i) == 1) ? "" : "s");
- if (REG_USERVAR_P (regno_reg_rtx[i]))
- fprintf (file, "; user var");
- if (REG_N_DEATHS (i) != 1)
- fprintf (file, "; dies in %d places", REG_N_DEATHS (i));
- if (REG_N_CALLS_CROSSED (i) == 1)
- fprintf (file, "; crosses 1 call");
- else if (REG_N_CALLS_CROSSED (i))
- fprintf (file, "; crosses %d calls", REG_N_CALLS_CROSSED (i));
- if (PSEUDO_REGNO_BYTES (i) != UNITS_PER_WORD)
- fprintf (file, "; %d bytes", PSEUDO_REGNO_BYTES (i));
- class = reg_preferred_class (i);
- altclass = reg_alternate_class (i);
- if (class != GENERAL_REGS || altclass != ALL_REGS)
- {
- if (altclass == ALL_REGS || class == ALL_REGS)
- fprintf (file, "; pref %s", reg_class_names[(int) class]);
- else if (altclass == NO_REGS)
- fprintf (file, "; %s or none", reg_class_names[(int) class]);
- else
- fprintf (file, "; pref %s, else %s",
- reg_class_names[(int) class],
- reg_class_names[(int) altclass]);
- }
- if (REG_POINTER (regno_reg_rtx[i]))
- fprintf (file, "; pointer");
- fprintf (file, ".\n");
- }
-
- fprintf (file, "\n%d basic blocks, %d edges.\n", n_basic_blocks, n_edges);
- for (i = 0; i < n_basic_blocks; i++)
- {
- register basic_block bb = BASIC_BLOCK (i);
- register edge e;
-
- fprintf (file, "\nBasic block %d: first insn %d, last %d, loop_depth %d, count ",
- i, INSN_UID (bb->head), INSN_UID (bb->end), bb->loop_depth);
- fprintf (file, HOST_WIDEST_INT_PRINT_DEC, (HOST_WIDEST_INT) bb->count);
- fprintf (file, ", freq %i.\n", bb->frequency);
-
- fprintf (file, "Predecessors: ");
- for (e = bb->pred; e; e = e->pred_next)
- dump_edge_info (file, e, 0);
-
- fprintf (file, "\nSuccessors: ");
- for (e = bb->succ; e; e = e->succ_next)
- dump_edge_info (file, e, 1);
-
- fprintf (file, "\nRegisters live at start:");
- dump_regset (bb->global_live_at_start, file);
-
- fprintf (file, "\nRegisters live at end:");
- dump_regset (bb->global_live_at_end, file);
-
- putc ('\n', file);
- }
-
- putc ('\n', file);
-}
-
-void
-debug_flow_info ()
-{
- dump_flow_info (stderr);
-}
-
-void
-dump_edge_info (file, e, do_succ)
- FILE *file;
- edge e;
- int do_succ;
-{
- basic_block side = (do_succ ? e->dest : e->src);
+ basic_block side = (do_succ ? e->dest : e->src);
if (side == ENTRY_BLOCK_PTR)
fputs (" ENTRY", file);
if (e->count)
{
fprintf (file, " count:");
- fprintf (file, HOST_WIDEST_INT_PRINT_DEC, (HOST_WIDEST_INT) e->count);
+ fprintf (file, HOST_WIDEST_INT_PRINT_DEC, e->count);
}
if (e->flags)
{
static const char * const bitnames[] = {
- "fallthru", "ab", "abcall", "eh", "fake", "dfs_back"
+ "fallthru", "ab", "abcall", "eh", "fake", "dfs_back",
+ "can_fallthru", "irreducible", "sibcall", "loop_exit"
};
int comma = 0;
int i, flags = e->flags;
- fputc (' ', file);
- fputc ('(', file);
+ fputs (" (", file);
for (i = 0; flags; i++)
if (flags & (1 << i))
{
fprintf (file, "%d", i);
comma = 1;
}
+
fputc (')', file);
}
}
\f
-/* Print out one basic block with live information at start and end. */
-
-void
-dump_bb (bb, outf)
- basic_block bb;
- FILE *outf;
-{
- rtx insn;
- rtx last;
- edge e;
+/* Simple routines to easily allocate AUX fields of basic blocks. */
- fprintf (outf, ";; Basic block %d, loop depth %d, count ",
- bb->index, bb->loop_depth);
- fprintf (outf, HOST_WIDEST_INT_PRINT_DEC, (HOST_WIDEST_INT) bb->count);
- putc ('\n', outf);
-
- fputs (";; Predecessors: ", outf);
- for (e = bb->pred; e; e = e->pred_next)
- dump_edge_info (outf, e, 0);
- putc ('\n', outf);
-
- fputs (";; Registers live at start:", outf);
- dump_regset (bb->global_live_at_start, outf);
- putc ('\n', outf);
-
- for (insn = bb->head, last = NEXT_INSN (bb->end);
- insn != last;
- insn = NEXT_INSN (insn))
- print_rtl_single (outf, insn);
-
- fputs (";; Registers live at end:", outf);
- dump_regset (bb->global_live_at_end, outf);
- putc ('\n', outf);
-
- fputs (";; Successors: ", outf);
- for (e = bb->succ; e; e = e->succ_next)
- dump_edge_info (outf, e, 1);
- putc ('\n', outf);
-}
+static struct obstack block_aux_obstack;
+static void *first_block_aux_obj = 0;
+static struct obstack edge_aux_obstack;
+static void *first_edge_aux_obj = 0;
-void
-debug_bb (bb)
- basic_block bb;
-{
- dump_bb (bb, stderr);
-}
+/* Allocate a memory block of SIZE as BB->aux. The obstack must
+ be first initialized by alloc_aux_for_blocks. */
-void
-debug_bb_n (n)
- int n;
+inline void
+alloc_aux_for_block (basic_block bb, int size)
{
- dump_bb (BASIC_BLOCK (n), stderr);
+ /* Verify that aux field is clear. */
+ if (bb->aux || !first_block_aux_obj)
+ abort ();
+ bb->aux = obstack_alloc (&block_aux_obstack, size);
+ memset (bb->aux, 0, size);
}
-/* Like print_rtl, but also print out live information for the start of each
- basic block. */
+/* Initialize the block_aux_obstack and if SIZE is nonzero, call
+ alloc_aux_for_block for each basic block. */
void
-print_rtl_with_bb (outf, rtx_first)
- FILE *outf;
- rtx rtx_first;
+alloc_aux_for_blocks (int size)
{
- register rtx tmp_rtx;
+ static int initialized;
- if (rtx_first == 0)
- fprintf (outf, "(nil)\n");
- else
+ if (!initialized)
{
- int i;
- enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB };
- int max_uid = get_max_uid ();
- basic_block *start = (basic_block *)
- xcalloc (max_uid, sizeof (basic_block));
- basic_block *end = (basic_block *)
- xcalloc (max_uid, sizeof (basic_block));
- enum bb_state *in_bb_p = (enum bb_state *)
- xcalloc (max_uid, sizeof (enum bb_state));
-
- for (i = n_basic_blocks - 1; i >= 0; i--)
- {
- basic_block bb = BASIC_BLOCK (i);
- rtx x;
-
- start[INSN_UID (bb->head)] = bb;
- end[INSN_UID (bb->end)] = bb;
- for (x = bb->head; x != NULL_RTX; x = NEXT_INSN (x))
- {
- enum bb_state state = IN_MULTIPLE_BB;
- if (in_bb_p[INSN_UID (x)] == NOT_IN_BB)
- state = IN_ONE_BB;
- in_bb_p[INSN_UID (x)] = state;
-
- if (x == bb->end)
- break;
- }
- }
-
- for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx))
- {
- int did_output;
- basic_block bb;
-
- if ((bb = start[INSN_UID (tmp_rtx)]) != NULL)
- {
- fprintf (outf, ";; Start of basic block %d, registers live:",
- bb->index);
- dump_regset (bb->global_live_at_start, outf);
- putc ('\n', outf);
- }
-
- if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB
- && GET_CODE (tmp_rtx) != NOTE
- && GET_CODE (tmp_rtx) != BARRIER)
- fprintf (outf, ";; Insn is not within a basic block\n");
- else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB)
- fprintf (outf, ";; Insn is in multiple basic blocks\n");
-
- did_output = print_rtl_single (outf, tmp_rtx);
-
- if ((bb = end[INSN_UID (tmp_rtx)]) != NULL)
- {
- fprintf (outf, ";; End of basic block %d, registers live:\n",
- bb->index);
- dump_regset (bb->global_live_at_end, outf);
- putc ('\n', outf);
- }
-
- if (did_output)
- putc ('\n', outf);
- }
-
- free (start);
- free (end);
- free (in_bb_p);
+ gcc_obstack_init (&block_aux_obstack);
+ initialized = 1;
}
- if (current_function_epilogue_delay_list != 0)
+ /* Check whether AUX data are still allocated. */
+ else if (first_block_aux_obj)
+ abort ();
+ first_block_aux_obj = obstack_alloc (&block_aux_obstack, 0);
+ if (size)
{
- fprintf (outf, "\n;; Insns in epilogue delay list:\n\n");
- for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0;
- tmp_rtx = XEXP (tmp_rtx, 1))
- print_rtl_single (outf, XEXP (tmp_rtx, 0));
+ basic_block bb;
+
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
+ alloc_aux_for_block (bb, size);
}
}
-\f
-/* Verify the CFG consistency. This function check some CFG invariants and
- aborts when something is wrong. Hope that this function will help to
- convert many optimization passes to preserve CFG consistent.
-
- Currently it does following checks:
-
- - test head/end pointers
- - overlapping of basic blocks
- - edge list correctness
- - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note)
- - tails of basic blocks (ensure that boundary is necesary)
- - scans body of the basic block for JUMP_INSN, CODE_LABEL
- and NOTE_INSN_BASIC_BLOCK
- - check that all insns are in the basic blocks
- (except the switch handling code, barriers and notes)
- - check that all returns are followed by barriers
-
- In future it can be extended check a lot of other stuff as well
- (reachability of basic blocks, life information, etc. etc.). */
+
+/* Clear AUX pointers of all blocks. */
void
-verify_flow_info ()
+clear_aux_for_blocks (void)
{
- const int max_uid = get_max_uid ();
- const rtx rtx_first = get_insns ();
- rtx last_head = get_last_insn ();
- basic_block *bb_info, *last_visited;
- size_t *edge_checksum;
- rtx x;
- int i, last_bb_num_seen, num_bb_notes, err = 0;
-
- bb_info = (basic_block *) xcalloc (max_uid, sizeof (basic_block));
- last_visited = (basic_block *) xcalloc (n_basic_blocks + 2,
- sizeof (basic_block));
- edge_checksum = (size_t *) xcalloc (n_basic_blocks + 2, sizeof (size_t));
-
- for (i = n_basic_blocks - 1; i >= 0; i--)
- {
- basic_block bb = BASIC_BLOCK (i);
- rtx head = bb->head;
- rtx end = bb->end;
-
- /* Verify the end of the basic block is in the INSN chain. */
- for (x = last_head; x != NULL_RTX; x = PREV_INSN (x))
- if (x == end)
- break;
- if (!x)
- {
- error ("End insn %d for block %d not found in the insn stream.",
- INSN_UID (end), bb->index);
- err = 1;
- }
+ basic_block bb;
- /* Work backwards from the end to the head of the basic block
- to verify the head is in the RTL chain. */
- for (; x != NULL_RTX; x = PREV_INSN (x))
- {
- /* While walking over the insn chain, verify insns appear
- in only one basic block and initialize the BB_INFO array
- used by other passes. */
- if (bb_info[INSN_UID (x)] != NULL)
- {
- error ("Insn %d is in multiple basic blocks (%d and %d)",
- INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index);
- err = 1;
- }
- bb_info[INSN_UID (x)] = bb;
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
+ bb->aux = NULL;
+}
- if (x == head)
- break;
- }
- if (!x)
- {
- error ("Head insn %d for block %d not found in the insn stream.",
- INSN_UID (head), bb->index);
- err = 1;
- }
+/* Free data allocated in block_aux_obstack and clear AUX pointers
+ of all blocks. */
- last_head = x;
- }
+void
+free_aux_for_blocks (void)
+{
+ if (!first_block_aux_obj)
+ abort ();
+ obstack_free (&block_aux_obstack, first_block_aux_obj);
+ first_block_aux_obj = NULL;
- /* Now check the basic blocks (boundaries etc.) */
- for (i = n_basic_blocks - 1; i >= 0; i--)
- {
- basic_block bb = BASIC_BLOCK (i);
- int has_fallthru = 0;
- edge e;
+ clear_aux_for_blocks ();
+}
- e = bb->succ;
- while (e)
- {
- if (last_visited [e->dest->index + 2] == bb)
- {
- error ("verify_flow_info: Duplicate edge %i->%i",
- e->src->index, e->dest->index);
- err = 1;
- }
- last_visited [e->dest->index + 2] = bb;
+/* Allocate a memory edge of SIZE as BB->aux. The obstack must
+ be first initialized by alloc_aux_for_edges. */
- if (e->flags & EDGE_FALLTHRU)
- has_fallthru = 1;
+inline void
+alloc_aux_for_edge (edge e, int size)
+{
+ /* Verify that aux field is clear. */
+ if (e->aux || !first_edge_aux_obj)
+ abort ();
+ e->aux = obstack_alloc (&edge_aux_obstack, size);
+ memset (e->aux, 0, size);
+}
- if ((e->flags & EDGE_FALLTHRU)
- && e->src != ENTRY_BLOCK_PTR
- && e->dest != EXIT_BLOCK_PTR)
- {
- rtx insn;
- if (e->src->index + 1 != e->dest->index)
- {
- error ("verify_flow_info: Incorrect blocks for fallthru %i->%i",
- e->src->index, e->dest->index);
- err = 1;
- }
- else
- for (insn = NEXT_INSN (e->src->end); insn != e->dest->head;
- insn = NEXT_INSN (insn))
- if (GET_CODE (insn) == BARRIER || INSN_P (insn))
- {
- error ("verify_flow_info: Incorrect fallthru %i->%i",
- e->src->index, e->dest->index);
- fatal_insn ("Wrong insn in the fallthru edge", insn);
- err = 1;
- }
- }
- if (e->src != bb)
- {
- error ("verify_flow_info: Basic block %d succ edge is corrupted",
- bb->index);
- fprintf (stderr, "Predecessor: ");
- dump_edge_info (stderr, e, 0);
- fprintf (stderr, "\nSuccessor: ");
- dump_edge_info (stderr, e, 1);
- fprintf (stderr, "\n");
- err = 1;
- }
- edge_checksum[e->dest->index + 2] += (size_t) e;
- e = e->succ_next;
- }
- if (!has_fallthru)
- {
- rtx insn = bb->end;
-
- /* Ensure existence of barrier in BB with no fallthru edges. */
- for (insn = bb->end; GET_CODE (insn) != BARRIER;
- insn = NEXT_INSN (insn))
- if (!insn
- || (GET_CODE (insn) == NOTE
- && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK))
- {
- error ("Missing barrier after block %i", bb->index);
- err = 1;
- }
- }
+/* Initialize the edge_aux_obstack and if SIZE is nonzero, call
+ alloc_aux_for_edge for each basic edge. */
- e = bb->pred;
- while (e)
- {
- if (e->dest != bb)
- {
- error ("Basic block %d pred edge is corrupted", bb->index);
- fputs ("Predecessor: ", stderr);
- dump_edge_info (stderr, e, 0);
- fputs ("\nSuccessor: ", stderr);
- dump_edge_info (stderr, e, 1);
- fputc ('\n', stderr);
- err = 1;
- }
- edge_checksum[e->dest->index + 2] -= (size_t) e;
- e = e->pred_next;
- }
- for (x = bb->head; x != NEXT_INSN (bb->end); x = NEXT_INSN (x))
- if (basic_block_for_insn && BLOCK_FOR_INSN (x) != bb)
- {
- debug_rtx (x);
- if (! BLOCK_FOR_INSN (x))
- error ("Insn %d is inside basic block %d but block_for_insn is NULL",
- INSN_UID (x), bb->index);
- else
- error ("Insn %d is inside basic block %d but block_for_insn is %i",
- INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index);
- err = 1;
- }
-
- /* OK pointers are correct. Now check the header of basic
- block. It ought to contain optional CODE_LABEL followed
- by NOTE_BASIC_BLOCK. */
- x = bb->head;
- if (GET_CODE (x) == CODE_LABEL)
- {
- if (bb->end == x)
- {
- error ("NOTE_INSN_BASIC_BLOCK is missing for block %d",
- bb->index);
- err = 1;
- }
- x = NEXT_INSN (x);
- }
- if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb)
- {
- error ("NOTE_INSN_BASIC_BLOCK is missing for block %d",
- bb->index);
- err = 1;
- }
+void
+alloc_aux_for_edges (int size)
+{
+ static int initialized;
- if (bb->end == x)
- {
- /* Do checks for empty blocks here */
- }
- else
- {
- x = NEXT_INSN (x);
- while (x)
- {
- if (NOTE_INSN_BASIC_BLOCK_P (x))
- {
- error ("NOTE_INSN_BASIC_BLOCK %d in the middle of basic block %d",
- INSN_UID (x), bb->index);
- err = 1;
- }
-
- if (x == bb->end)
- break;
-
- if (GET_CODE (x) == JUMP_INSN
- || GET_CODE (x) == CODE_LABEL
- || GET_CODE (x) == BARRIER)
- {
- error ("In basic block %d:", bb->index);
- fatal_insn ("Flow control insn inside a basic block", x);
- }
-
- x = NEXT_INSN (x);
- }
- }
+ if (!initialized)
+ {
+ gcc_obstack_init (&edge_aux_obstack);
+ initialized = 1;
}
- /* Complete edge checksumming for ENTRY and EXIT. */
- {
- edge e;
- for (e = ENTRY_BLOCK_PTR->succ; e ; e = e->succ_next)
- edge_checksum[e->dest->index + 2] += (size_t) e;
- for (e = EXIT_BLOCK_PTR->pred; e ; e = e->pred_next)
- edge_checksum[e->dest->index + 2] -= (size_t) e;
- }
+ /* Check whether AUX data are still allocated. */
+ else if (first_edge_aux_obj)
+ abort ();
- for (i = -2; i < n_basic_blocks; ++i)
- if (edge_checksum[i + 2])
- {
- error ("Basic block %i edge lists are corrupted", i);
- err = 1;
- }
-
- last_bb_num_seen = -1;
- num_bb_notes = 0;
- x = rtx_first;
- while (x)
+ first_edge_aux_obj = obstack_alloc (&edge_aux_obstack, 0);
+ if (size)
{
- if (NOTE_INSN_BASIC_BLOCK_P (x))
- {
- basic_block bb = NOTE_BASIC_BLOCK (x);
- num_bb_notes++;
- if (bb->index != last_bb_num_seen + 1)
- internal_error ("Basic blocks not numbered consecutively.");
+ basic_block bb;
- last_bb_num_seen = bb->index;
- }
-
- if (!bb_info[INSN_UID (x)])
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
{
- switch (GET_CODE (x))
- {
- case BARRIER:
- case NOTE:
- break;
-
- case CODE_LABEL:
- /* An addr_vec is placed outside any block block. */
- if (NEXT_INSN (x)
- && GET_CODE (NEXT_INSN (x)) == JUMP_INSN
- && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC
- || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC))
- {
- x = NEXT_INSN (x);
- }
-
- /* But in any case, non-deletable labels can appear anywhere. */
- break;
-
- default:
- fatal_insn ("Insn outside basic block", x);
- }
- }
-
- if (INSN_P (x)
- && GET_CODE (x) == JUMP_INSN
- && returnjump_p (x) && ! condjump_p (x)
- && ! (NEXT_INSN (x) && GET_CODE (NEXT_INSN (x)) == BARRIER))
- fatal_insn ("Return not followed by barrier", x);
+ edge e;
- x = NEXT_INSN (x);
+ for (e = bb->succ; e; e = e->succ_next)
+ alloc_aux_for_edge (e, size);
+ }
}
-
- if (num_bb_notes != n_basic_blocks)
- internal_error
- ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)",
- num_bb_notes, n_basic_blocks);
-
- if (err)
- internal_error ("verify_flow_info failed.");
-
- /* Clean up. */
- free (bb_info);
- free (last_visited);
- free (edge_checksum);
}
-\f
-/* Assume that the preceeding pass has possibly eliminated jump instructions
- or converted the unconditional jumps. Eliminate the edges from CFG.
- Return true if any edges are eliminated. */
-bool
-purge_dead_edges (bb)
- basic_block bb;
+/* Clear AUX pointers of all edges. */
+
+void
+clear_aux_for_edges (void)
{
- edge e, next;
- rtx insn = bb->end;
- bool purged = false;
+ basic_block bb;
+ edge e;
- if (GET_CODE (insn) == JUMP_INSN && !simplejump_p (insn))
- return false;
- if (GET_CODE (insn) == JUMP_INSN)
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
{
- rtx note;
- edge b,f;
- /* We do care only about conditional jumps and simplejumps. */
- if (!any_condjump_p (insn)
- && !returnjump_p (insn)
- && !simplejump_p (insn))
- return false;
- for (e = bb->succ; e; e = next)
- {
- next = e->succ_next;
-
- /* Check purposes we can have edge. */
- if ((e->flags & EDGE_FALLTHRU)
- && any_condjump_p (insn))
- continue;
- if (e->dest != EXIT_BLOCK_PTR
- && e->dest->head == JUMP_LABEL (insn))
- continue;
- if (e->dest == EXIT_BLOCK_PTR
- && returnjump_p (insn))
- continue;
- purged = true;
- remove_edge (e);
- }
- if (!bb->succ || !purged)
- return false;
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Purged edges from bb %i\n", bb->index);
- if (!optimize)
- return purged;
-
- /* Redistribute probabilities. */
- if (!bb->succ->succ_next)
- {
- bb->succ->probability = REG_BR_PROB_BASE;
- bb->succ->count = bb->count;
- }
- else
- {
- note = find_reg_note (insn, REG_BR_PROB, NULL);
- if (!note)
- return purged;
- b = BRANCH_EDGE (bb);
- f = FALLTHRU_EDGE (bb);
- b->probability = INTVAL (XEXP (note, 0));
- f->probability = REG_BR_PROB_BASE - b->probability;
- b->count = bb->count * b->probability / REG_BR_PROB_BASE;
- f->count = bb->count * f->probability / REG_BR_PROB_BASE;
- }
- return purged;
+ for (e = bb->succ; e; e = e->succ_next)
+ e->aux = NULL;
}
+}
- /* Cleanup abnormal edges caused by throwing insns that have been
- eliminated. */
- if (! can_throw_internal (bb->end))
- for (e = bb->succ; e; e = next)
- {
- next = e->succ_next;
- if (e->flags & EDGE_EH)
- {
- remove_edge (e);
- purged = true;
- }
- }
-
- /* If we don't see a jump insn, we don't know exactly why the block would
- have been broken at this point. Look for a simple, non-fallthru edge,
- as these are only created by conditional branches. If we find such an
- edge we know that there used to be a jump here and can then safely
- remove all non-fallthru edges. */
- for (e = bb->succ; e && (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU));
- e = e->succ_next);
- if (!e)
- return purged;
- for (e = bb->succ; e; e = next)
- {
- next = e->succ_next;
- if (!(e->flags & EDGE_FALLTHRU))
- remove_edge (e), purged = true;
- }
- if (!bb->succ || bb->succ->succ_next)
+/* Free data allocated in edge_aux_obstack and clear AUX pointers
+ of all edges. */
+
+void
+free_aux_for_edges (void)
+{
+ if (!first_edge_aux_obj)
abort ();
- bb->succ->probability = REG_BR_PROB_BASE;
- bb->succ->count = bb->count;
+ obstack_free (&edge_aux_obstack, first_edge_aux_obj);
+ first_edge_aux_obj = NULL;
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Purged non-fallthru edges from bb %i\n",
- bb->index);
- return purged;
+ clear_aux_for_edges ();
}
-/* Search all basic blocks for potentionally dead edges and purge them.
-
- Return true ifif some edge has been elliminated.
- */
+void
+debug_bb (basic_block bb)
+{
+ dump_bb (bb, stderr, 0);
+}
-bool
-purge_all_dead_edges ()
+basic_block
+debug_bb_n (int n)
{
- int i, purged = false;
- for (i = 0; i < n_basic_blocks; i++)
- purged |= purge_dead_edges (BASIC_BLOCK (i));
- return purged;
+ basic_block bb = BASIC_BLOCK (n);
+ dump_bb (bb, stderr, 0);
+ return bb;
}
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