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flow.c (delete_dead_jumptables): New function.

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* flow.c (delete_dead_jumptables): New function.
	(life_analyzis): Call it.
	* bb-reorder.c (skip_insns_after_block): Handle contradictive sequences.

From-SVN: r44365
This commit is contained in:
Jan Hubicka 2001-07-25 22:51:24 +02:00 committed by Jan Hubicka
parent 7f206d8f42
commit 6e64a52a92
3 changed files with 102 additions and 16 deletions
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6
gcc/ChangeLog
View File

@ -1,3 +1,9 @@
Wed Jul 25 22:48:59 CEST 2001 Jan Hubicka <jh@suse.cz>
* flow.c (delete_dead_jumptables): New function.
(life_analyzis): Call it.
* bb-reorder.c (skip_insns_after_block): Handle contradictive sequences.
2001-07-25 Richard Henderson <rth@redhat.com>
* except.c (reachable_handlers): Handle a region being removed

33
gcc/bb-reorder.c
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@ -205,7 +205,7 @@ static rtx
skip_insns_after_block (bb)
basic_block bb;
{
rtx insn, last_insn, next_head;
rtx insn, last_insn, next_head, prev;
next_head = NULL_RTX;
if (bb->index + 1 != n_basic_blocks)
@ -234,11 +234,6 @@ skip_insns_after_block (bb)
continue;
default:
/* Make line notes attached to the succesor block unless they
are followed by something attached to predecesor block.
These notes remained after removing code in the predecesor
block and thus should be kept together. */
if (NOTE_LINE_NUMBER (insn) >= 0)
continue;
break;
}
@ -262,6 +257,32 @@ skip_insns_after_block (bb)
break;
}
/* It is possible to hit contradicting sequence. For instance:
jump_insn
NOTE_INSN_LOOP_BEG
barrier
Where barrier belongs to jump_insn, but the note does not.
This can be created by removing the basic block originally
following NOTE_INSN_LOOP_BEG.
In such case reorder the notes. */
for (insn = last_insn; insn != bb->end; insn = prev)
{
prev = PREV_INSN (insn);
if (GET_CODE (insn) == NOTE)
switch (NOTE_LINE_NUMBER (insn))
{
case NOTE_INSN_LOOP_END:
case NOTE_INSN_BLOCK_END:
case NOTE_INSN_DELETED:
case NOTE_INSN_DELETED_LABEL:
continue;
default:
reorder_insns (insn, insn, last_insn);
}
}
return last_insn;
}

73
gcc/flow.c
View File

@ -481,6 +481,7 @@ static void flow_loop_tree_node_add PARAMS ((struct loop *, struct loop *));
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 delete_dead_jumptables PARAMS ((void));
/* Find basic blocks of the current function.
F is the first insn of the function and NREGS the number of register
@ -4081,6 +4082,8 @@ life_analysis (f, file, flags)
}
}
#endif
/* Removing dead insns should've made jumptables really dead. */
delete_dead_jumptables ();
}
/* A subroutine of verify_wide_reg, called through for_each_rtx.
@ -4334,6 +4337,32 @@ delete_noop_moves (f)
}
}
/* Delete any jump tables never referenced. We can't delete them at the
time of removing tablejump insn as they are referenced by the preceeding
insns computing the destination, so we delay deleting and garbagecollect
them once life information is computed. */
static void
delete_dead_jumptables ()
{
rtx insn, next;
for (insn = get_insns (); insn; insn = next)
{
next = NEXT_INSN (insn);
if (GET_CODE (insn) == CODE_LABEL
&& LABEL_NUSES (insn) == 0
&& GET_CODE (next) == JUMP_INSN
&& (GET_CODE (PATTERN (next)) == ADDR_VEC
|| GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC))
{
if (rtl_dump_file)
fprintf (rtl_dump_file, "Dead jumptable %i removed\n", INSN_UID (insn));
flow_delete_insn (NEXT_INSN (insn));
flow_delete_insn (insn);
next = NEXT_INSN (next);
}
}
}
/* Determine if the stack pointer is constant over the life of the function.
Only useful before prologues have been emitted. */
@ -7956,7 +7985,7 @@ set_block_for_new_insns (insn, bb)
- test head/end pointers
- overlapping of basic blocks
- edge list corectness
- 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
@ -8031,8 +8060,9 @@ verify_flow_info ()
for (i = n_basic_blocks - 1; i >= 0; i--)
{
basic_block bb = BASIC_BLOCK (i);
/* Check corectness of edge lists */
/* Check correctness of edge lists. */
edge e;
int has_fallthru = 0;
e = bb->succ;
while (e)
@ -8045,17 +8075,31 @@ verify_flow_info ()
}
last_visited [e->dest->index + 2] = bb;
if (e->flags & EDGE_FALLTHRU)
has_fallthru = 1;
if ((e->flags & EDGE_FALLTHRU)
&& e->src != ENTRY_BLOCK_PTR
&& e->dest != EXIT_BLOCK_PTR
&& (e->src->index + 1 != e->dest->index
|| !can_fallthru (e->src, e->dest)))
&& e->dest != EXIT_BLOCK_PTR)
{
error ("verify_flow_info: Incorrect fallthru edge %i->%i",
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",
@ -8080,6 +8124,21 @@ verify_flow_info ()
}
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;
}
}
e = bb->pred;
while (e)