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flow.c (find_sub_basic_blocks): New function.

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* flow.c (find_sub_basic_blocks): New function.
	(split_block): Be ready for basic block introduced by CODE_LABEL.
	(commit_one_edge_insertion): Call find_sub_basic_block.

	* flow.c (make_edges): Add edge from entry for blocks starting with
	label having ALTERNATE_NAME

From-SVN: r40021
This commit is contained in:
Jan Hubicka 2001-02-24 03:32:33 +01:00 committed by Jan Hubicka
parent 016030fea6
commit a686dbf86a
2 changed files with 130 additions and 5 deletions
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9
gcc/ChangeLog
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@ -1,3 +1,12 @@
Sat Feb 24 03:30:38 CET 2001 Jan Hubicka <jh@suse.cz>
* flow.c (find_sub_basic_blocks): New function.
(split_block): Be ready for basic block introduced by CODE_LABEL.
(commit_one_edge_insertion): Call find_sub_basic_block.
* flow.c (make_edges): Add edge from entry for blocks starting with
label having ALTERNATE_NAME
Sat Feb 24 03:19:42 CET 2001 Jan Hubicka <jh@suse.cz>
* function.c (epilogue_done): Be ready for first basic block not

126
gcc/flow.c
View File

@ -473,6 +473,7 @@ static void flow_loops_tree_build PARAMS ((struct loops *));
static int flow_loop_level_compute PARAMS ((struct loop *, int));
static int flow_loops_level_compute PARAMS ((struct loops *));
static void allocate_bb_life_data PARAMS ((void));
static void find_sub_basic_blocks PARAMS ((basic_block));
/* Find basic blocks of the current function.
F is the first insn of the function and NREGS the number of register
@ -697,6 +698,106 @@ find_label_refs (f, lvl)
return lvl;
}
/* Assume that someone emitted code with control flow instructions to the
basic block. Update the data structure. */
static void
find_sub_basic_blocks (bb)
basic_block bb;
{
rtx first_insn = bb->head, insn;
rtx end = bb->end;
edge succ_list = bb->succ;
rtx jump_insn = NULL_RTX;
int created = 0;
int barrier = 0;
edge falltru = 0;
basic_block first_bb = bb, last_bb;
int i;
if (GET_CODE (first_insn) == LABEL_REF)
first_insn = NEXT_INSN (first_insn);
first_insn = NEXT_INSN (first_insn);
bb->succ = NULL;
insn = first_insn;
/* Scan insn chain and try to find new basic block boundaries. */
while (insn != end)
{
enum rtx_code code = GET_CODE (insn);
switch (code)
{
case JUMP_INSN:
/* We need some special care for those expressions. */
if (GET_CODE (PATTERN (insn)) == ADDR_VEC
|| GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)
abort();
jump_insn = insn;
break;
case BARRIER:
if (!jump_insn)
abort ();
barrier = 1;
break;
/* On code label, split current basic block. */
case CODE_LABEL:
falltru = split_block (bb, PREV_INSN (insn));
if (jump_insn)
bb->end = jump_insn;
bb = falltru->dest;
if (barrier)
remove_edge (falltru);
barrier = 0;
jump_insn = 0;
created = 1;
if (LABEL_ALTERNATE_NAME (insn))
make_edge (NULL, ENTRY_BLOCK_PTR, bb, 0);
break;
case INSN:
/* In case we've previously split insn on the JUMP_INSN, move the
block header to proper place. */
if (jump_insn)
{
falltru = split_block (bb, PREV_INSN (insn));
bb->end = jump_insn;
bb = falltru->dest;
if (barrier)
abort ();
jump_insn = 0;
}
default:
break;
}
insn = NEXT_INSN (insn);
}
/* Last basic block must end in the original BB end. */
if (jump_insn)
abort ();
/* Wire in the original edges for last basic block. */
if (created)
{
bb->succ = succ_list;
while (succ_list)
succ_list->src = bb, succ_list = succ_list->succ_next;
}
else
bb->succ = succ_list;
/* Now re-scan and wire in all edges. This expect simple (conditional)
jumps at the end of each new basic blocks. */
last_bb = bb;
for (i = first_bb->index; i < last_bb->index; i++)
{
bb = BASIC_BLOCK (i);
if (GET_CODE (bb->end) == JUMP_INSN)
{
mark_jump_label (PATTERN (bb->end), bb->end, 0, 0);
make_label_edge (NULL, bb, JUMP_LABEL (bb->end), 0);
}
insn = NEXT_INSN (insn);
}
}
/* Find all basic blocks of the function whose first insn is F.
Collect and return a list of labels whose addresses are taken. This
@ -1121,6 +1222,10 @@ make_edges (label_value_list)
enum rtx_code code;
int force_fallthru = 0;
if (GET_CODE (bb->head) == CODE_LABEL
&& LABEL_ALTERNATE_NAME (bb->head))
make_edge (NULL, ENTRY_BLOCK_PTR, bb, 0);
/* Examine the last instruction of the block, and discover the
ways we can leave the block. */
@ -1589,11 +1694,21 @@ split_block (bb, insn)
BASIC_BLOCK (i) = new_bb;
new_bb->index = i;
/* Create the basic block note. */
bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK,
new_bb->head);
NOTE_BASIC_BLOCK (bb_note) = new_bb;
new_bb->head = bb_note;
if (GET_CODE (new_bb->head) == CODE_LABEL)
{
/* Create the basic block note. */
bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK,
new_bb->head);
NOTE_BASIC_BLOCK (bb_note) = new_bb;
}
else
{
/* Create the basic block note. */
bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK,
new_bb->head);
NOTE_BASIC_BLOCK (bb_note) = new_bb;
new_bb->head = bb_note;
}
update_bb_for_insn (new_bb);
@ -1995,6 +2110,7 @@ commit_one_edge_insertion (e)
}
else if (GET_CODE (last) == JUMP_INSN)
abort ();
find_sub_basic_blocks (bb);
}
/* Update the CFG for all queued instructions. */