bitmap.h (bitmap_and_into): Update prototype.

	* bitmap.h (bitmap_and_into): Update prototype.
	* bitmap.c (bitmap_and_into): Return true if the target bitmap
	changed, false otherwise.

	* df.h (df_dump_insn_problem_function): New function type.
	(struct df_problem): Add two functions, to dump just before and
	just after an insn.
	(DF_RD_PRUNE_DEAD_DEFS): New changable flag.
	(df_dump_insn_top, df_dump_insn_bottom): New prototypes.
	* df-core (df_dump_region): Use dump_bb.
	(df_dump_bb_problem_data): New function.
	(df_dump_top, df_dump_bottom): Rewrite using df_dump_bb_problem_data.
	(df_dump_insn_problem_data): New function.
	(df_dump_insn_top, df_dump_insn_bottom): New functions.
	* df-scan.c (problem_SCAN): Add NULL fields for new members.
	* df-problems.c (df_rd_local_compute): Ignore hard registers if
	DF_NO_HARD_REGS is in effect.
	(df_rd_transfer_function): If DF_RD_PRUNE_DEAD_DEFS is in effect,
	prune reaching defs using the LR problem.
	(df_rd_start_dump): Fix dumping of DEFs map.
	(df_rd_dump_defs_set): New function.
	(df_rd_top_dump, df_rd_bottom_dump): Use it.
	(problem_RD): Add NULL fields for new members.
	(problem_LR, problem_LIVE): Likewise.
	(df_chain_bb_dump): New function.
	(df_chain_top_dump): Dump only for artificial DEFs and USEs,
	using df_chain_bb_dump.
	(df_chain_bottom_dump): Likewise.
	(df_chain_insn_top_dump, df_chain_insn_bottom_dump): New functions.
	(problem_CHAIN): Add them as new members.
	(problem_WORD_LR, problem_NOTE): Add NULL fields for new members.
	(problem_MD): Likewise.
	* cfgrtl.c (rtl_dump_bb): Use df_dump_insn_top and df_dump_insn_bottom.
	(print_rtl_with_bb): Likewise.

	* dce.c (init_dce): Use DF_RD_PRUNE_DEAD_DEFS.
	* loop-invariant.c (find_defs): Likewise.
	* loop-iv.c (iv_analysis_loop_init): Likewise.
	* ree.c (find_and_remove_re): Likewise.
	* web.c (web_main): Likewise.

From-SVN: r192213

1 files changed, 16 insertions, 5 deletions

diff --git a/gcc/bitmap.c b/gcc/bitmap.c
index 63f0e09..76f70fc 100644
--- a/gcc/bitmap.c
+++ b/gcc/bitmap.c
@@ -916,17 +916,18 @@ bitmap_and (bitmap dst, const_bitmap a, const_bitmap b)
     dst->indx = dst->current->indx;
 }
 
-/* A &= B.  */
+/* A &= B.  Return true if A changed.  */
 
-void
+bool
 bitmap_and_into (bitmap a, const_bitmap b)
 {
   bitmap_element *a_elt = a->first;
   const bitmap_element *b_elt = b->first;
   bitmap_element *next;
+  bool changed = false;
 
   if (a == b)
-    return;
+    return false;
 
   while (a_elt && b_elt)
     {
@@ -935,6 +936,7 @@ bitmap_and_into (bitmap a, const_bitmap b)
 	  next = a_elt->next;
 	  bitmap_element_free (a, a_elt);
 	  a_elt = next;
+	  changed = true;
 	}
       else if (b_elt->indx < a_elt->indx)
 	b_elt = b_elt->next;
@@ -947,7 +949,8 @@ bitmap_and_into (bitmap a, const_bitmap b)
 	  for (ix = 0; ix < BITMAP_ELEMENT_WORDS; ix++)
 	    {
 	      BITMAP_WORD r = a_elt->bits[ix] & b_elt->bits[ix];
-
+	      if (a_elt->bits[ix] != r)
+		changed = true;
 	      a_elt->bits[ix] = r;
 	      ior |= r;
 	    }
@@ -958,9 +961,17 @@ bitmap_and_into (bitmap a, const_bitmap b)
 	  b_elt = b_elt->next;
 	}
     }
-  bitmap_elt_clear_from (a, a_elt);
+
+  if (a_elt)
+    {
+      changed = true;
+      bitmap_elt_clear_from (a, a_elt);
+    }
+
   gcc_checking_assert (!a->current == !a->first
 		       && (!a->current || a->indx == a->current->indx));
+
+  return changed;
 }