* gfortran.texi: Use @table @emph instead of @itemize @emph.

[pf3gnuchains/gcc-fork.git] / gcc / ifcvt.c

diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c
index 976098f..a6066da 100644 (file)
--- a/gcc/ifcvt.c
+++ b/gcc/ifcvt.c
@@ -612,6 +612,7 @@ static int noce_try_cmove_arith (struct noce_if_info *);
 static rtx noce_get_alt_condition (struct noce_if_info *, rtx, rtx *);
 static int noce_try_minmax (struct noce_if_info *);
 static int noce_try_abs (struct noce_if_info *);
+static int noce_try_sign_mask (struct noce_if_info *);
 
 /* Helper function for noce_try_store_flag*.  */
 
@@ -1702,6 +1703,71 @@ noce_try_abs (struct noce_if_info *if_info)
   return TRUE;
 }
 
+/* Convert "if (m < 0) x = b; else x = 0;" to "x = (m >> C) & b;".  */
+
+static int
+noce_try_sign_mask (struct noce_if_info *if_info)
+{
+  rtx cond, t, m, c, seq;
+  enum machine_mode mode;
+  enum rtx_code code;
+
+  if (no_new_pseudos)
+    return FALSE;
+
+  cond = if_info->cond;
+  code = GET_CODE (cond);
+  m = XEXP (cond, 0);
+  c = XEXP (cond, 1);
+
+  t = NULL_RTX;
+  if (if_info->a == const0_rtx)
+    {
+      if ((code == LT && c == const0_rtx)
+         || (code == LE && c == constm1_rtx))
+       t = if_info->b;
+    }
+  else if (if_info->b == const0_rtx)
+    {
+      if ((code == GE && c == const0_rtx)
+         || (code == GT && c == constm1_rtx))
+       t = if_info->a;
+    }
+
+  if (! t || side_effects_p (t))
+    return FALSE;
+
+  /* We currently don't handle different modes.  */
+  mode = GET_MODE (t);
+  if (GET_MODE (m) != mode)
+    return FALSE;
+
+  /* This is only profitable if T is cheap.  */
+  if (rtx_cost (t, SET) >= COSTS_N_INSNS (2))
+    return FALSE;
+
+  start_sequence ();
+  c = gen_int_mode (GET_MODE_BITSIZE (mode) - 1, mode);
+  m = expand_binop (mode, ashr_optab, m, c, NULL_RTX, 0, OPTAB_DIRECT);
+  t = m ? expand_binop (mode, and_optab, m, t, NULL_RTX, 0, OPTAB_DIRECT)
+       : NULL_RTX;
+
+  if (!t)
+    {
+      end_sequence ();
+      return FALSE;
+    }
+
+  noce_emit_move_insn (if_info->x, t);
+  seq = get_insns ();
+  unshare_ifcvt_sequence (if_info, seq);
+  end_sequence ();
+  emit_insn_before_setloc (seq, if_info->jump,
+                          INSN_LOCATOR (if_info->insn_a));
+  return TRUE;
+}
+
+
 /* Similar to get_condition, only the resulting condition must be
    valid at JUMP, instead of at EARLIEST.  */
 
@@ -2004,6 +2070,8 @@ noce_process_if_block (struct ce_if_block * ce_info)
       if (HAVE_conditional_move
          && noce_try_cmove_arith (&if_info))
        goto success;
+      if (noce_try_sign_mask (&if_info))
+       goto success;
     }
 
   return FALSE;
@@ -2783,6 +2851,18 @@ find_if_case_1 (basic_block test_bb, edge then_edge, edge else_edge)
   edge then_succ = then_bb->succ;
   int then_bb_index;
 
+  /* If we are partitioning hot/cold basic blocks, we don't want to
+     mess up unconditional or indirect jumps that cross between hot
+     and cold sections.  */
+  
+  if (flag_reorder_blocks_and_partition
+      && ((BB_END (then_bb) 
+          && find_reg_note (BB_END (then_bb), REG_CROSSING_JUMP, NULL_RTX))
+         || (BB_END (else_bb)
+             && find_reg_note (BB_END (else_bb), REG_CROSSING_JUMP, 
+                               NULL_RTX))))
+    return FALSE;
+
   /* THEN has one successor.  */
   if (!then_succ || then_succ->succ_next != NULL)
     return FALSE;
@@ -2851,6 +2931,18 @@ find_if_case_2 (basic_block test_bb, edge then_edge, edge else_edge)
   edge else_succ = else_bb->succ;
   rtx note;
 
+  /* If we are partitioning hot/cold basic blocks, we don't want to
+     mess up unconditional or indirect jumps that cross between hot
+     and cold sections.  */
+  
+  if (flag_reorder_blocks_and_partition
+      && ((BB_END (then_bb)
+          && find_reg_note (BB_END (then_bb), REG_CROSSING_JUMP, NULL_RTX))
+         || (BB_END (else_bb) 
+             && find_reg_note (BB_END (else_bb), REG_CROSSING_JUMP, 
+                               NULL_RTX))))
+    return FALSE;
+
   /* ELSE has one successor.  */
   if (!else_succ || else_succ->succ_next != NULL)
     return FALSE;
@@ -2931,7 +3023,7 @@ static int
 dead_or_predicable (basic_block test_bb, basic_block merge_bb,
                    basic_block other_bb, basic_block new_dest, int reversep)
 {
-  rtx head, end, jump, earliest, old_dest, new_label = NULL_RTX;
+  rtx head, end, jump, earliest = NULL_RTX, old_dest, new_label = NULL_RTX;
 
   jump = BB_END (test_bb);
 
@@ -3195,13 +3287,10 @@ if_convert (int x_life_data_ok)
   num_true_changes = 0;
   life_data_ok = (x_life_data_ok != 0);
 
-  if (! (* targetm.cannot_modify_jumps_p) ())
+  if ((! targetm.cannot_modify_jumps_p ())
+      && (!flag_reorder_blocks_and_partition || !no_new_pseudos))
     mark_loop_exit_edges ();
 
-  /* Free up basic_block_for_insn so that we don't have to keep it
-     up to date, either here or in merge_blocks.  */
-  free_basic_block_vars (1);
-
   /* Compute postdominators if we think we'll use them.  */
   if (HAVE_conditional_execution || life_data_ok)
     calculate_dominance_info (CDI_POST_DOMINATORS);