/* 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"
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;
}
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;
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 (targetm.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
- && (! targetm.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 (targetm.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. */
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]
}
/* 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)));
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