bitmap.c (bitmap_elem_to_freelist): Set indx to -1.

2016-10-07  Richard Biener  <rguenther@suse.de>

	* bitmap.c (bitmap_elem_to_freelist): Set indx to -1.
	* bitmap.h (bmp_iter_set): When advancing to the next element
	check that we didn't remove the current one.
	(bmp_iter_and): Likewise.
	(bmp_iter_and_compl): Likewise.
	* tree-ssa.c (release_defs_bitset): Do not remove worklist bit
	we currently iterate on but keep a one-level queue.
	* sched-deps.c (remove_from_deps): Do not clear current bit
	but keep a one-level queue.

From-SVN: r240859

5 files changed, 94 insertions, 46 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1be7817..56e5fd9 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2016-10-07  Richard Biener  <rguenther@suse.de>
+
+	* bitmap.c (bitmap_elem_to_freelist): Set indx to -1.
+	* bitmap.h (bmp_iter_set): When advancing to the next element
+	check that we didn't remove the current one.
+	(bmp_iter_and): Likewise.
+	(bmp_iter_and_compl): Likewise.
+	* tree-ssa.c (release_defs_bitset): Do not remove worklist bit
+	we currently iterate on but keep a one-level queue.
+	* sched-deps.c (remove_from_deps): Do not clear current bit
+	but keep a one-level queue.
+
 2016-10-07  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/77664
diff --git a/gcc/bitmap.c b/gcc/bitmap.c
index 6206535..1a32332 100644
--- a/gcc/bitmap.c
+++ b/gcc/bitmap.c
@@ -66,6 +66,7 @@ bitmap_elem_to_freelist (bitmap head, bitmap_element *elt)
   bitmap_obstack *bit_obstack = head->obstack;
 
   elt->next = NULL;
+  elt->indx = -1;
   if (bit_obstack)
     {
       elt->prev = bit_obstack->elements;
diff --git a/gcc/bitmap.h b/gcc/bitmap.h
index 1115711..e4e80d6 100644
--- a/gcc/bitmap.h
+++ b/gcc/bitmap.h
@@ -618,6 +618,9 @@ bmp_iter_set (bitmap_iterator *bi, unsigned *bit_no)
 	  bi->word_no++;
 	}
 
+      /* Make sure we didn't remove the element while iterating.  */
+      gcc_checking_assert (bi->elt1->indx != -1U);
+
       /* Advance to the next element.  */
       bi->elt1 = bi->elt1->next;
       if (!bi->elt1)
@@ -664,6 +667,9 @@ bmp_iter_and (bitmap_iterator *bi, unsigned *bit_no)
       /* Advance to the next identical element.  */
       do
 	{
+	  /* Make sure we didn't remove the element while iterating.  */
+	  gcc_checking_assert (bi->elt1->indx != -1U);
+
 	  /* Advance elt1 while it is less than elt2.  We always want
 	     to advance one elt.  */
 	  do
@@ -674,6 +680,9 @@ bmp_iter_and (bitmap_iterator *bi, unsigned *bit_no)
 	    }
 	  while (bi->elt1->indx < bi->elt2->indx);
 
+	  /* Make sure we didn't remove the element while iterating.  */
+	  gcc_checking_assert (bi->elt2->indx != -1U);
+
 	  /* Advance elt2 to be no less than elt1.  This might not
 	     advance.  */
 	  while (bi->elt2->indx < bi->elt1->indx)
@@ -726,11 +735,17 @@ bmp_iter_and_compl (bitmap_iterator *bi, unsigned *bit_no)
 	  bi->word_no++;
 	}
 
+      /* Make sure we didn't remove the element while iterating.  */
+      gcc_checking_assert (bi->elt1->indx != -1U);
+
       /* Advance to the next element of elt1.  */
       bi->elt1 = bi->elt1->next;
       if (!bi->elt1)
 	return false;
 
+      /* Make sure we didn't remove the element while iterating.  */
+      gcc_checking_assert (! bi->elt2 || bi->elt2->indx != -1U);
+
       /* Advance elt2 until it is no less than elt1.  */
       while (bi->elt2 && bi->elt2->indx < bi->elt1->indx)
 	bi->elt2 = bi->elt2->next;
diff --git a/gcc/sched-deps.c b/gcc/sched-deps.c
index 41a6af2..dc46351 100644
--- a/gcc/sched-deps.c
+++ b/gcc/sched-deps.c
@@ -3992,8 +3992,14 @@ remove_from_deps (struct deps_desc *deps, rtx_insn *insn)
   removed = remove_from_dependence_list (insn, &deps->last_pending_memory_flush);
   deps->pending_flush_length -= removed;
 
+  unsigned to_clear = -1U;
   EXECUTE_IF_SET_IN_REG_SET (&deps->reg_last_in_use, 0, i, rsi)
     {
+      if (to_clear != -1U)
+	{
+	  CLEAR_REGNO_REG_SET (&deps->reg_last_in_use, to_clear);
+	  to_clear = -1U;
+	}
       struct deps_reg *reg_last = &deps->reg_last[i];
       if (reg_last->uses)
 	remove_from_dependence_list (insn, &reg_last->uses);
@@ -4005,8 +4011,10 @@ remove_from_deps (struct deps_desc *deps, rtx_insn *insn)
 	remove_from_dependence_list (insn, &reg_last->clobbers);
       if (!reg_last->uses && !reg_last->sets && !reg_last->implicit_sets
 	  && !reg_last->clobbers)
-        CLEAR_REGNO_REG_SET (&deps->reg_last_in_use, i);
+	to_clear = i;
     }
+  if (to_clear != -1U)
+    CLEAR_REGNO_REG_SET (&deps->reg_last_in_use, to_clear);
 
   if (CALL_P (insn))
     {
diff --git a/gcc/tree-ssa.c b/gcc/tree-ssa.c
index d442a5f..261d9b0 100644
--- a/gcc/tree-ssa.c
+++ b/gcc/tree-ssa.c
@@ -551,58 +551,70 @@ release_defs_bitset (bitmap toremove)
      most likely run in slightly superlinear time, rather than the
      pathological quadratic worst case.  */
   while (!bitmap_empty_p (toremove))
-    EXECUTE_IF_SET_IN_BITMAP (toremove, 0, j, bi)
-      {
-	bool remove_now = true;
-	tree var = ssa_name (j);
-	gimple *stmt;
-	imm_use_iterator uit;
-
-	FOR_EACH_IMM_USE_STMT (stmt, uit, var)
-	  {
-	    ssa_op_iter dit;
-	    def_operand_p def_p;
+    {
+      unsigned to_remove_bit = -1U;
+      EXECUTE_IF_SET_IN_BITMAP (toremove, 0, j, bi)
+	{
+	  if (to_remove_bit != -1U)
+	    {
+	      bitmap_clear_bit (toremove, to_remove_bit);
+	      to_remove_bit = -1U;
+	    }
 
-	    /* We can't propagate PHI nodes into debug stmts.  */
-	    if (gimple_code (stmt) == GIMPLE_PHI
-		|| is_gimple_debug (stmt))
-	      continue;
+	  bool remove_now = true;
+	  tree var = ssa_name (j);
+	  gimple *stmt;
+	  imm_use_iterator uit;
 
-	    /* If we find another definition to remove that uses
-	       the one we're looking at, defer the removal of this
-	       one, so that it can be propagated into debug stmts
-	       after the other is.  */
-	    FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, dit, SSA_OP_DEF)
-	      {
-		tree odef = DEF_FROM_PTR (def_p);
+	  FOR_EACH_IMM_USE_STMT (stmt, uit, var)
+	    {
+	      ssa_op_iter dit;
+	      def_operand_p def_p;
+
+	      /* We can't propagate PHI nodes into debug stmts.  */
+	      if (gimple_code (stmt) == GIMPLE_PHI
+		  || is_gimple_debug (stmt))
+		continue;
+
+	      /* If we find another definition to remove that uses
+		 the one we're looking at, defer the removal of this
+		 one, so that it can be propagated into debug stmts
+		 after the other is.  */
+	      FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, dit, SSA_OP_DEF)
+		{
+		  tree odef = DEF_FROM_PTR (def_p);
 
-		if (bitmap_bit_p (toremove, SSA_NAME_VERSION (odef)))
-		  {
-		    remove_now = false;
-		    break;
-		  }
-	      }
+		  if (bitmap_bit_p (toremove, SSA_NAME_VERSION (odef)))
+		    {
+		      remove_now = false;
+		      break;
+		    }
+		}
 
-	    if (!remove_now)
-	      BREAK_FROM_IMM_USE_STMT (uit);
-	  }
+	      if (!remove_now)
+		BREAK_FROM_IMM_USE_STMT (uit);
+	    }
 
-	if (remove_now)
-	  {
-	    gimple *def = SSA_NAME_DEF_STMT (var);
-	    gimple_stmt_iterator gsi = gsi_for_stmt (def);
+	  if (remove_now)
+	    {
+	      gimple *def = SSA_NAME_DEF_STMT (var);
+	      gimple_stmt_iterator gsi = gsi_for_stmt (def);
 
-	    if (gimple_code (def) == GIMPLE_PHI)
-	      remove_phi_node (&gsi, true);
-	    else
-	      {
-		gsi_remove (&gsi, true);
-		release_defs (def);
-	      }
+	      if (gimple_code (def) == GIMPLE_PHI)
+		remove_phi_node (&gsi, true);
+	      else
+		{
+		  gsi_remove (&gsi, true);
+		  release_defs (def);
+		}
+
+	      to_remove_bit = j;
+	    }
+	}
+      if (to_remove_bit != -1U)
+	bitmap_clear_bit (toremove, to_remove_bit);
+    }
 
-	    bitmap_clear_bit (toremove, j);
-	  }
-      }
 }
 
 /* Verify virtual SSA form.  */