/* If-conversion support.
- Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+ Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2010
Free Software Foundation, Inc.
This file is part of GCC.
#include "hard-reg-set.h"
#include "basic-block.h"
#include "expr.h"
-#include "real.h"
#include "output.h"
#include "optabs.h"
#include "toplev.h"
#include "vecprim.h"
#include "dbgcnt.h"
-#ifndef HAVE_conditional_execution
-#define HAVE_conditional_execution 0
-#endif
#ifndef HAVE_conditional_move
#define HAVE_conditional_move 0
#endif
rtx false_expr; /* test for then block insns */
rtx true_prob_val; /* probability of else block */
rtx false_prob_val; /* probability of then block */
- int n_insns;
+ rtx then_last_head = NULL_RTX; /* Last match at the head of THEN */
+ rtx else_last_head = NULL_RTX; /* Last match at the head of ELSE */
+ rtx then_first_tail = NULL_RTX; /* First match at the tail of THEN */
+ rtx else_first_tail = NULL_RTX; /* First match at the tail of ELSE */
+ int then_n_insns, else_n_insns, n_insns;
enum rtx_code false_code;
/* If test is comprised of && or || elements, and we've failed at handling
number of insns and see if it is small enough to convert. */
then_start = first_active_insn (then_bb);
then_end = last_active_insn (then_bb, TRUE);
- n_insns = ce_info->num_then_insns = count_bb_insns (then_bb);
+ then_n_insns = ce_info->num_then_insns = count_bb_insns (then_bb);
+ n_insns = then_n_insns;
max = MAX_CONDITIONAL_EXECUTE;
if (else_bb)
{
+ int n_matching;
+
max *= 2;
else_start = first_active_insn (else_bb);
else_end = last_active_insn (else_bb, TRUE);
- n_insns += ce_info->num_else_insns = count_bb_insns (else_bb);
+ else_n_insns = ce_info->num_else_insns = count_bb_insns (else_bb);
+ n_insns += else_n_insns;
+
+ /* Look for matching sequences at the head and tail of the two blocks,
+ and limit the range of insns to be converted if possible. */
+ n_matching = flow_find_cross_jump (then_bb, else_bb,
+ &then_first_tail, &else_first_tail);
+ if (then_first_tail == BB_HEAD (then_bb))
+ then_start = then_end = NULL_RTX;
+ if (else_first_tail == BB_HEAD (else_bb))
+ else_start = else_end = NULL_RTX;
+
+ if (n_matching > 0)
+ {
+ if (then_end)
+ then_end = prev_active_insn (then_first_tail);
+ if (else_end)
+ else_end = prev_active_insn (else_first_tail);
+ n_insns -= 2 * n_matching;
+ }
+
+ if (then_start && else_start)
+ {
+ int longest_match = MIN (then_n_insns - n_matching,
+ else_n_insns - n_matching);
+ n_matching
+ = flow_find_head_matching_sequence (then_bb, else_bb,
+ &then_last_head,
+ &else_last_head,
+ longest_match);
+
+ if (n_matching > 0)
+ {
+ rtx insn;
+
+ /* We won't pass the insns in the head sequence to
+ cond_exec_process_insns, so we need to test them here
+ to make sure that they don't clobber the condition. */
+ for (insn = BB_HEAD (then_bb);
+ insn != NEXT_INSN (then_last_head);
+ insn = NEXT_INSN (insn))
+ if (!LABEL_P (insn) && !NOTE_P (insn)
+ && !DEBUG_INSN_P (insn)
+ && modified_in_p (test_expr, insn))
+ return FALSE;
+ }
+
+ if (then_last_head == then_end)
+ then_start = then_end = NULL_RTX;
+ if (else_last_head == else_end)
+ else_start = else_end = NULL_RTX;
+
+ if (n_matching > 0)
+ {
+ if (then_start)
+ then_start = next_active_insn (then_last_head);
+ if (else_start)
+ else_start = next_active_insn (else_last_head);
+ n_insns -= 2 * n_matching;
+ }
+ }
}
if (n_insns > max)
fprintf (dump_file, "%d insn%s converted to conditional execution.\n",
n_insns, (n_insns == 1) ? " was" : "s were");
- /* Merge the blocks! */
+ /* Merge the blocks! If we had matching sequences, make sure to delete one
+ copy at the appropriate location first: delete the copy in the THEN branch
+ for a tail sequence so that the remaining one is executed last for both
+ branches, and delete the copy in the ELSE branch for a head sequence so
+ that the remaining one is executed first for both branches. */
+ if (then_first_tail)
+ {
+ rtx from = then_first_tail;
+ if (!INSN_P (from))
+ from = next_active_insn (from);
+ delete_insn_chain (from, BB_END (then_bb), false);
+ }
+ if (else_last_head)
+ delete_insn_chain (first_active_insn (else_bb), else_last_head, false);
+
merge_if_block (ce_info);
cond_exec_changed_p = TRUE;
return TRUE;
if insn_rtx_cost can't be estimated. */
if (insn_a)
{
- insn_cost = insn_rtx_cost (PATTERN (insn_a),
- optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn_a)));
+ insn_cost
+ = insn_rtx_cost (PATTERN (insn_a),
+ optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn_a)));
if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (if_info->branch_cost))
return FALSE;
}
if (insn_b)
{
- insn_cost += insn_rtx_cost (PATTERN (insn_b),
- optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn_b)));
+ insn_cost
+ += insn_rtx_cost (PATTERN (insn_b),
+ optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn_b)));
if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (if_info->branch_cost))
return FALSE;
}
/* First, look to see if we put a constant in a register. */
prev_insn = prev_nonnote_insn (if_info->cond_earliest);
if (prev_insn
- && BLOCK_NUM (prev_insn) == BLOCK_NUM (if_info->cond_earliest)
+ && BLOCK_FOR_INSN (prev_insn)
+ == BLOCK_FOR_INSN (if_info->cond_earliest)
&& INSN_P (prev_insn)
&& GET_CODE (PATTERN (prev_insn)) == SET)
{
{
rtx set, insn = prev_nonnote_insn (earliest);
if (insn
- && BLOCK_NUM (insn) == BLOCK_NUM (earliest)
+ && BLOCK_FOR_INSN (insn) == BLOCK_FOR_INSN (earliest)
&& (set = single_set (insn))
&& rtx_equal_p (SET_DEST (set), c))
{
COND_EARLIEST to JUMP. Make sure the relevant data is still
intact. */
if (! insn_b
- || BLOCK_NUM (insn_b) != BLOCK_NUM (if_info->cond_earliest)
+ || BLOCK_FOR_INSN (insn_b) != BLOCK_FOR_INSN (if_info->cond_earliest)
|| !NONJUMP_INSN_P (insn_b)
|| (set_b = single_set (insn_b)) == NULL_RTX
|| ! rtx_equal_p (x, SET_DEST (set_b))
the lifetime of hard registers on small register class machines. */
orig_x = x;
if (!REG_P (x)
- || (SMALL_REGISTER_CLASSES
- && REGNO (x) < FIRST_PSEUDO_REGISTER))
+ || (HARD_REGISTER_P (x)
+ && targetm.small_register_classes_for_mode_p (GET_MODE (x))))
{
if (GET_MODE (x) == BLKmode)
return FALSE;
if (HAVE_conditional_move
&& noce_try_cmove (if_info))
goto success;
- if (! HAVE_conditional_execution)
+ if (! targetm.have_conditional_execution ())
{
if (noce_try_store_flag_constants (if_info))
goto success;
REGS. COND is the condition we will test. */
static int
-check_cond_move_block (basic_block bb, rtx *vals, VEC (int, heap) **regs, rtx cond)
+check_cond_move_block (basic_block bb, rtx *vals, VEC (int, heap) **regs,
+ rtx cond)
{
rtx insn;
dest = SET_DEST (set);
src = SET_SRC (set);
if (!REG_P (dest)
- || (SMALL_REGISTER_CLASSES && HARD_REGISTER_P (dest)))
+ || (HARD_REGISTER_P (dest)
+ && targetm.small_register_classes_for_mode_p (GET_MODE (dest))))
return FALSE;
if (!CONSTANT_P (src) && !register_operand (src, VOIDmode))
/* Make sure the blocks are suitable. */
if (!check_cond_move_block (then_bb, then_vals, &then_regs, cond)
- || (else_bb && !check_cond_move_block (else_bb, else_vals, &else_regs, cond)))
+ || (else_bb
+ && !check_cond_move_block (else_bb, else_vals, &else_regs, cond)))
{
VEC_free (int, heap, then_regs);
VEC_free (int, heap, else_regs);
Return TRUE if we were successful at converting the block. */
static int
-noce_find_if_block (basic_block test_bb,
- edge then_edge, edge else_edge,
+noce_find_if_block (basic_block test_bb, edge then_edge, edge else_edge,
int pass)
{
basic_block then_bb, else_bb, join_bb;
return FALSE;
/* If this is not a standard conditional jump, we can't parse it. */
- cond = noce_get_condition (jump,
- &cond_earliest,
- then_else_reversed);
+ cond = noce_get_condition (jump, &cond_earliest, then_else_reversed);
if (!cond)
return FALSE;
/* Otherwise this must be a multiway branch of some sort. */
return NULL;
- memset (&ce_info, '\0', sizeof (ce_info));
+ memset (&ce_info, 0, sizeof (ce_info));
ce_info.test_bb = test_bb;
ce_info.then_bb = then_edge->dest;
ce_info.else_bb = else_edge->dest;
IFCVT_INIT_EXTRA_FIELDS (&ce_info);
#endif
- if (! reload_completed
+ if (!reload_completed
&& noce_find_if_block (test_bb, then_edge, else_edge, pass))
goto success;
- if (HAVE_conditional_execution && reload_completed
+ if (reload_completed
+ && targetm.have_conditional_execution ()
&& cond_exec_find_if_block (&ce_info))
goto success;
goto success;
if (dom_info_state (CDI_POST_DOMINATORS) >= DOM_NO_FAST_QUERY
- && (! HAVE_conditional_execution || reload_completed))
+ && (reload_completed || !targetm.have_conditional_execution ()))
{
if (find_if_case_1 (test_bb, then_edge, else_edge))
goto success;
ce_info->last_test_bb = test_bb;
/* We only ever should get here after reload,
- and only if we have conditional execution. */
- gcc_assert (HAVE_conditional_execution && reload_completed);
+ and if we have conditional execution. */
+ gcc_assert (reload_completed && targetm.have_conditional_execution ());
/* Discover if any fall through predecessors of the current test basic block
were && tests (which jump to the else block) or || tests (which jump to
if (EDGE_COUNT (then_bb->succs) > 0
&& (!single_succ_p (then_bb)
|| (single_succ_edge (then_bb)->flags & EDGE_COMPLEX)
- || (epilogue_completed && tablejump_p (BB_END (then_bb), NULL, NULL))))
+ || (epilogue_completed
+ && tablejump_p (BB_END (then_bb), NULL, NULL))))
return FALSE;
/* If the THEN block has no successors, conditional execution can still
else if (single_succ_p (else_bb)
&& single_succ (then_bb) == single_succ (else_bb)
&& single_pred_p (else_bb)
- && ! (single_succ_edge (else_bb)->flags & EDGE_COMPLEX)
- && ! (epilogue_completed && tablejump_p (BB_END (else_bb), NULL, NULL)))
+ && !(single_succ_edge (else_bb)->flags & EDGE_COMPLEX)
+ && !(epilogue_completed
+ && tablejump_p (BB_END (else_bb), NULL, NULL)))
join_bb = single_succ (else_bb);
/* Otherwise it is not an IF-THEN or IF-THEN-ELSE combination. */
test_bb->index, else_bb->index);
/* ELSE is small. */
- if (! cheap_bb_rtx_cost_p (else_bb,
+ if (! cheap_bb_rtx_cost_p (else_bb,
COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (else_edge->src),
predictable_edge_p (else_edge)))))
return FALSE;
/* Disable handling dead code by conditional execution if the machine needs
to do anything funny with the tests, etc. */
#ifndef IFCVT_MODIFY_TESTS
- if (HAVE_conditional_execution)
+ if (targetm.have_conditional_execution ())
{
/* In the conditional execution case, we have things easy. We know
the condition is reversible. We don't have to check life info
that any registers modified are dead at the branch site. */
rtx insn, cond, prev;
- bitmap merge_set, test_live, test_set;
+ bitmap merge_set, merge_set_noclobber, test_live, test_set;
unsigned i, fail = 0;
bitmap_iterator bi;
/* Collect:
MERGE_SET = set of registers set in MERGE_BB
+ MERGE_SET_NOCLOBBER = like MERGE_SET, but only includes registers
+ that are really set, not just clobbered.
TEST_LIVE = set of registers live at EARLIEST
- TEST_SET = set of registers set between EARLIEST and the
- end of the block. */
+ TEST_SET = set of registers set between EARLIEST and the
+ end of the block. */
merge_set = BITMAP_ALLOC (®_obstack);
+ merge_set_noclobber = BITMAP_ALLOC (®_obstack);
test_live = BITMAP_ALLOC (®_obstack);
test_set = BITMAP_ALLOC (®_obstack);
{
if (NONDEBUG_INSN_P (insn))
{
- unsigned int uid = INSN_UID (insn);
- df_ref *def_rec;
- for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
- {
- df_ref def = *def_rec;
- bitmap_set_bit (merge_set, DF_REF_REGNO (def));
- }
+ df_simulate_find_defs (insn, merge_set);
+ df_simulate_find_noclobber_defs (insn, merge_set_noclobber);
}
}
/* For small register class machines, don't lengthen lifetimes of
hard registers before reload. */
- if (SMALL_REGISTER_CLASSES && ! reload_completed)
+ if (! reload_completed
+ && targetm.small_register_classes_for_mode_p (VOIDmode))
{
- EXECUTE_IF_SET_IN_BITMAP (merge_set, 0, i, bi)
+ EXECUTE_IF_SET_IN_BITMAP (merge_set_noclobber, 0, i, bi)
{
if (i < FIRST_PSEUDO_REGISTER
&& ! fixed_regs[i]
fail = 1;
}
}
-
+
/* For TEST, we're interested in a range of insns, not a whole block.
Moreover, we're interested in the insns live from OTHER_BB. */
-
- /* The loop below takes the set of live registers
+
+ /* The loop below takes the set of live registers
after JUMP, and calculates the live set before EARLIEST. */
bitmap_copy (test_live, df_get_live_in (other_bb));
df_simulate_initialize_backwards (test_bb, test_live);
}
/* We can perform the transformation if
- MERGE_SET & (TEST_SET | TEST_LIVE)
+ MERGE_SET_NOCLOBBER & TEST_SET
+ and
+ MERGE_SET & TEST_LIVE)
and
TEST_SET & DF_LIVE_IN (merge_bb)
are empty. */
- if (bitmap_intersect_p (test_set, merge_set)
+ if (bitmap_intersect_p (test_set, merge_set_noclobber)
|| bitmap_intersect_p (test_live, merge_set)
|| bitmap_intersect_p (test_set, df_get_live_in (merge_bb)))
fail = 1;
+ BITMAP_FREE (merge_set_noclobber);
BITMAP_FREE (merge_set);
BITMAP_FREE (test_live);
BITMAP_FREE (test_set);
if (! note)
continue;
set = single_set (insn);
- if (!set || !function_invariant_p (SET_SRC (set)))
+ if (!set || !function_invariant_p (SET_SRC (set))
+ || !function_invariant_p (XEXP (note, 0)))
remove_note (insn, note);
} while (insn != end && (insn = NEXT_INSN (insn)));
FOR_EACH_BB (bb)
{
basic_block new_bb;
- while (!df_get_bb_dirty (bb)
+ while (!df_get_bb_dirty (bb)
&& (new_bb = find_if_header (bb, pass)) != NULL)
bb = new_bb;
}
#ifdef IFCVT_MULTIPLE_DUMPS
if (dump_file && cond_exec_changed_p)
- print_rtl_with_bb (dump_file, get_insns ());
+ {
+ if (dump_flags & TDF_SLIM)
+ print_rtl_slim_with_bb (dump_file, get_insns (), dump_flags);
+ else
+ print_rtl_with_bb (dump_file, get_insns ());
+ }
#endif
}
while (cond_exec_changed_p);