ifcvt.c (struct noce_if_info): Add comments to the fields.
* ifcvt.c (struct noce_if_info): Add comments to the fields. Remove the b_unconditional field. (noce_try_sign_mask): Do not look at b_unconditional. (noce_process_if_block): Do not use merge_if_blocks. Update the CFG here. Do not set b_unconditional. (cond_move_process_if_block): Likewise. (find_cond_trap): Likewise. (check_cond_move_block): Require simple jump insns at the end of the basic block. From-SVN: r120686
This commit is contained in:
Steven Bosscher
parent
90d715b0a5
commit
2a33a75f60
|
|
@ -1,3 +1,15 @@
|
|||
2007-01-11 Steven Bosscher <steven@gcc.gnu.org>
|
||||
|
||||
* ifcvt.c (struct noce_if_info): Add comments to the fields.
|
||||
Remove the b_unconditional field.
|
||||
(noce_try_sign_mask): Do not look at b_unconditional.
|
||||
(noce_process_if_block): Do not use merge_if_blocks. Update
|
||||
the CFG here. Do not set b_unconditional.
|
||||
(cond_move_process_if_block): Likewise.
|
||||
(find_cond_trap): Likewise.
|
||||
(check_cond_move_block): Require simple jump insns at the end
|
||||
of the basic block.
|
||||
|
||||
2007-01-11 Jan Hubicka <jh@suse.cz>
|
||||
|
||||
PR tree-optimization/1046
|
||||
|
|
|
|||
148
gcc/ifcvt.c
148
gcc/ifcvt.c
|
|
@ -596,12 +596,31 @@ cond_exec_process_if_block (ce_if_block_t * ce_info,
|
|||
|
||||
struct noce_if_info
|
||||
{
|
||||
/* A basic block that ends in a simple conditional jump. */
|
||||
basic_block test_bb;
|
||||
|
||||
/* The jump that ends TEST_BB. */
|
||||
rtx jump;
|
||||
|
||||
/* The jump condition. */
|
||||
rtx cond;
|
||||
|
||||
/* New insns should be inserted before this one. */
|
||||
rtx cond_earliest;
|
||||
|
||||
/* Insns in the THEN and ELSE block. There is always just this
|
||||
one insns in those blocks. The insns are single_set insns.
|
||||
If there was no ELSE block, INSN_B is the last insn before
|
||||
COND_EARLIEST, or NULL_RTX. In the former case, the insn
|
||||
operands are still valid, as if INSN_B was moved down below
|
||||
the jump. */
|
||||
rtx insn_a, insn_b;
|
||||
rtx x, a, b;
|
||||
rtx jump, cond, cond_earliest;
|
||||
/* True if "b" was originally evaluated unconditionally. */
|
||||
bool b_unconditional;
|
||||
|
||||
/* The SET_SRC of INSN_A and INSN_B. */
|
||||
rtx a, b;
|
||||
|
||||
/* The SET_DEST of INSN_A. */
|
||||
rtx x;
|
||||
};
|
||||
|
||||
static rtx noce_emit_store_flag (struct noce_if_info *, rtx, int, int);
|
||||
|
|
@ -1877,9 +1896,10 @@ noce_try_sign_mask (struct noce_if_info *if_info)
|
|||
return FALSE;
|
||||
|
||||
/* This is only profitable if T is cheap, or T is unconditionally
|
||||
executed/evaluated in the original insn sequence. */
|
||||
executed/evaluated in the original insn sequence. The latter
|
||||
happens if INSN_B was taken from TEST_BB. */
|
||||
if (rtx_cost (t, SET) >= COSTS_N_INSNS (2)
|
||||
&& (!if_info->b_unconditional
|
||||
&& (BLOCK_FOR_INSN (if_info->insn_b) != if_info->test_bb
|
||||
|| t != if_info->b))
|
||||
return FALSE;
|
||||
|
||||
|
|
@ -2173,6 +2193,7 @@ noce_process_if_block (struct ce_if_block * ce_info)
|
|||
basic_block test_bb = ce_info->test_bb; /* test block */
|
||||
basic_block then_bb = ce_info->then_bb; /* THEN */
|
||||
basic_block else_bb = ce_info->else_bb; /* ELSE or NULL */
|
||||
basic_block join_bb;
|
||||
struct noce_if_info if_info;
|
||||
rtx insn_a, insn_b;
|
||||
rtx set_a, set_b;
|
||||
|
|
@ -2283,7 +2304,6 @@ noce_process_if_block (struct ce_if_block * ce_info)
|
|||
if_info.x = x;
|
||||
if_info.a = a;
|
||||
if_info.b = b;
|
||||
if_info.b_unconditional = else_bb == 0;
|
||||
|
||||
/* Try optimizations in some approximation of a useful order. */
|
||||
/* ??? Should first look to see if X is live incoming at all. If it
|
||||
|
|
@ -2364,39 +2384,47 @@ noce_process_if_block (struct ce_if_block * ce_info)
|
|||
return FALSE;
|
||||
|
||||
success:
|
||||
/* The original sets may now be killed. */
|
||||
delete_insn (insn_a);
|
||||
|
||||
/* Several special cases here: First, we may have reused insn_b above,
|
||||
in which case insn_b is now NULL. Second, we want to delete insn_b
|
||||
if it came from the ELSE block, because follows the now correct
|
||||
write that appears in the TEST block. However, if we got insn_b from
|
||||
the TEST block, it may in fact be loading data needed for the comparison.
|
||||
We'll let life_analysis remove the insn if it's really dead. */
|
||||
if (insn_b && else_bb)
|
||||
delete_insn (insn_b);
|
||||
|
||||
/* The new insns will have been inserted immediately before the jump. We
|
||||
should be able to remove the jump with impunity, but the condition itself
|
||||
may have been modified by gcse to be shared across basic blocks. */
|
||||
delete_insn (jump);
|
||||
|
||||
/* If we used a temporary, fix it up now. */
|
||||
if (orig_x != x)
|
||||
{
|
||||
rtx seq;
|
||||
|
||||
start_sequence ();
|
||||
noce_emit_move_insn (orig_x, x);
|
||||
insn_b = get_insns ();
|
||||
seq = get_insns ();
|
||||
set_used_flags (orig_x);
|
||||
unshare_all_rtl_in_chain (insn_b);
|
||||
unshare_all_rtl_in_chain (seq);
|
||||
end_sequence ();
|
||||
|
||||
emit_insn_after_setloc (insn_b, BB_END (test_bb), INSN_LOCATOR (insn_a));
|
||||
emit_insn_before_setloc (seq, BB_END (test_bb), INSN_LOCATOR (insn_a));
|
||||
}
|
||||
|
||||
/* Merge the blocks! */
|
||||
merge_if_block (ce_info);
|
||||
/* The original THEN and ELSE blocks may now be removed. The test block
|
||||
must now jump to the join block. If the test block and the join block
|
||||
can be merged, do so. */
|
||||
|
||||
join_bb = single_succ (then_bb);
|
||||
if (else_bb)
|
||||
{
|
||||
delete_basic_block (else_bb);
|
||||
num_true_changes++;
|
||||
}
|
||||
else
|
||||
remove_edge (find_edge (test_bb, join_bb));
|
||||
|
||||
remove_edge (find_edge (then_bb, join_bb));
|
||||
redirect_edge_and_branch_force (single_succ_edge (test_bb), join_bb);
|
||||
delete_basic_block (then_bb);
|
||||
num_true_changes++;
|
||||
|
||||
if (can_merge_blocks_p (test_bb, join_bb))
|
||||
{
|
||||
merge_blocks (test_bb, join_bb);
|
||||
num_true_changes++;
|
||||
}
|
||||
|
||||
num_updated_if_blocks++;
|
||||
return TRUE;
|
||||
}
|
||||
|
||||
|
|
@ -2463,6 +2491,12 @@ check_cond_move_block (basic_block bb, rtx *vals, rtx cond)
|
|||
return FALSE;
|
||||
}
|
||||
|
||||
/* We can only handle simple jumps at the end of the basic block.
|
||||
It is almost impossible to update the CFG otherwise. */
|
||||
insn = BB_END (bb);
|
||||
if (JUMP_P (insn) && ! onlyjump_p (insn))
|
||||
return FALSE;
|
||||
|
||||
return TRUE;
|
||||
}
|
||||
|
||||
|
|
@ -2537,10 +2571,12 @@ cond_move_convert_if_block (struct noce_if_info *if_infop,
|
|||
static int
|
||||
cond_move_process_if_block (struct ce_if_block *ce_info)
|
||||
{
|
||||
basic_block test_bb = ce_info->test_bb;
|
||||
basic_block then_bb = ce_info->then_bb;
|
||||
basic_block else_bb = ce_info->else_bb;
|
||||
basic_block join_bb;
|
||||
struct noce_if_info if_info;
|
||||
rtx jump, cond, insn, seq, loc_insn;
|
||||
rtx jump, cond, seq, loc_insn;
|
||||
int max_reg, size, c, i;
|
||||
rtx *then_vals;
|
||||
rtx *else_vals;
|
||||
|
|
@ -2624,21 +2660,30 @@ cond_move_process_if_block (struct ce_if_block *ce_info)
|
|||
}
|
||||
emit_insn_before_setloc (seq, jump, INSN_LOCATOR (loc_insn));
|
||||
|
||||
FOR_BB_INSNS (then_bb, insn)
|
||||
if (INSN_P (insn) && !JUMP_P (insn))
|
||||
delete_insn (insn);
|
||||
join_bb = single_succ (then_bb);
|
||||
if (else_bb)
|
||||
{
|
||||
FOR_BB_INSNS (else_bb, insn)
|
||||
if (INSN_P (insn) && !JUMP_P (insn))
|
||||
delete_insn (insn);
|
||||
delete_basic_block (else_bb);
|
||||
num_true_changes++;
|
||||
}
|
||||
delete_insn (jump);
|
||||
else
|
||||
remove_edge (find_edge (test_bb, join_bb));
|
||||
|
||||
merge_if_block (ce_info);
|
||||
remove_edge (find_edge (then_bb, join_bb));
|
||||
redirect_edge_and_branch_force (single_succ_edge (test_bb), join_bb);
|
||||
delete_basic_block (then_bb);
|
||||
num_true_changes++;
|
||||
|
||||
if (can_merge_blocks_p (test_bb, join_bb))
|
||||
{
|
||||
merge_blocks (test_bb, join_bb);
|
||||
num_true_changes++;
|
||||
}
|
||||
|
||||
num_updated_if_blocks++;
|
||||
return TRUE;
|
||||
}
|
||||
|
||||
|
||||
/* Attempt to convert an IF-THEN or IF-THEN-ELSE block into
|
||||
straight line code. Return true if successful. */
|
||||
|
|
@ -3201,29 +3246,20 @@ find_cond_trap (basic_block test_bb, edge then_edge, edge else_edge)
|
|||
if (seq == NULL)
|
||||
return FALSE;
|
||||
|
||||
num_true_changes++;
|
||||
|
||||
/* Emit the new insns before cond_earliest. */
|
||||
emit_insn_before_setloc (seq, cond_earliest, INSN_LOCATOR (trap));
|
||||
|
||||
/* Delete the trap block if possible. */
|
||||
remove_edge (trap_bb == then_bb ? then_edge : else_edge);
|
||||
if (EDGE_COUNT (trap_bb->preds) == 0)
|
||||
delete_basic_block (trap_bb);
|
||||
|
||||
/* If the non-trap block and the test are now adjacent, merge them.
|
||||
Otherwise we must insert a direct branch. */
|
||||
if (test_bb->next_bb == other_bb)
|
||||
{
|
||||
struct ce_if_block new_ce_info;
|
||||
delete_insn (jump);
|
||||
memset (&new_ce_info, '\0', sizeof (new_ce_info));
|
||||
new_ce_info.test_bb = test_bb;
|
||||
new_ce_info.then_bb = NULL;
|
||||
new_ce_info.else_bb = NULL;
|
||||
new_ce_info.join_bb = other_bb;
|
||||
merge_if_block (&new_ce_info);
|
||||
delete_basic_block (trap_bb);
|
||||
num_true_changes++;
|
||||
}
|
||||
|
||||
/* Wire together the blocks again. */
|
||||
if (current_ir_type () == IR_RTL_CFGLAYOUT)
|
||||
single_succ_edge (test_bb)->flags |= EDGE_FALLTHRU;
|
||||
else
|
||||
{
|
||||
rtx lab, newjump;
|
||||
|
|
@ -3233,10 +3269,16 @@ find_cond_trap (basic_block test_bb, edge then_edge, edge else_edge)
|
|||
LABEL_NUSES (lab) += 1;
|
||||
JUMP_LABEL (newjump) = lab;
|
||||
emit_barrier_after (newjump);
|
||||
}
|
||||
delete_insn (jump);
|
||||
|
||||
delete_insn (jump);
|
||||
if (can_merge_blocks_p (test_bb, other_bb))
|
||||
{
|
||||
merge_blocks (test_bb, other_bb);
|
||||
num_true_changes++;
|
||||
}
|
||||
|
||||
num_updated_if_blocks++;
|
||||
return TRUE;
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue