gcc/

	* df.h (df_mw_hardreg): Remove "loc" field.
	* df-scan.c (df_ref_record): Don't set it.  Remove redundant
	local variable.
	* df-problems.c (df_whole_mw_reg_unused_p): New function,
	split out from df_set_unused_notes_for_mw.  Return false for
	partial references.  Assert that mw_reg is a REG when returning true.
	(df_set_unused_notes_for_mw): Use it.  Use mw_reg instead of *loc.
	(df_whole_mw_reg_dead_p): New function, split out from
	df_set_dead_notes_for_mw.  Return false for partial references.
	Assert that mw_reg is a REG when returning true.
	(df_set_dead_notes_for_mw): Use it.  Use mw_reg instead of *loc.
	Remove redundant bitmap check.


git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@126970 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 77 insertions, 32 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c9c7e30ff07..4865f2be933 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,18 @@
+2007-07-27  Richard Sandiford  <rsandifo@nildram.co.uk>
+
+	* df.h (df_mw_hardreg): Remove "loc" field.
+	* df-scan.c (df_ref_record): Don't set it.  Remove redundant
+	local variable.
+	* df-problems.c (df_whole_mw_reg_unused_p): New function,
+	split out from df_set_unused_notes_for_mw.  Return false for
+	partial references.  Assert that mw_reg is a REG when returning true.
+	(df_set_unused_notes_for_mw): Use it.  Use mw_reg instead of *loc.
+	(df_whole_mw_reg_dead_p): New function, split out from
+	df_set_dead_notes_for_mw.  Return false for partial references.
+	Assert that mw_reg is a REG when returning true.
+	(df_set_dead_notes_for_mw): Use it.  Use mw_reg instead of *loc.
+	Remove redundant bitmap check.
+
 2007-07-26  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* config/ia64/t-ia64 ($(T)crtbegin.o): Removed.
diff --git a/gcc/df-problems.c b/gcc/df-problems.c
index 4dcb3b15dd0..b3ae9a1620f 100644
--- a/gcc/df-problems.c
+++ b/gcc/df-problems.c
@@ -3716,6 +3716,32 @@ df_set_note (enum reg_note note_type, rtx insn, rtx old, rtx reg)
   return old;
 }
 
+/* A subroutine of df_set_unused_notes_for_mw, with a selection of its
+   arguments.  Return true if the register value described by MWS's
+   mw_reg is known to be completely unused, and if mw_reg can therefore
+   be used in a REG_UNUSED note.  */
+
+static bool
+df_whole_mw_reg_unused_p (struct df_mw_hardreg *mws,
+			  bitmap live, bitmap artificial_uses)
+{
+  unsigned int r;
+
+  /* If MWS describes a partial reference, create REG_UNUSED notes for
+     individual hard registers.  */
+  if (mws->flags & DF_REF_PARTIAL)
+    return false;
+
+  /* Likewise if some part of the register is used.  */
+  for (r = mws->start_regno; r <= mws->end_regno; r++)
+    if (bitmap_bit_p (live, r)
+	|| bitmap_bit_p (artificial_uses, r))
+      return false;
+
+  gcc_assert (REG_P (mws->mw_reg));
+  return true;
+}
+
 /* Set the REG_UNUSED notes for the multiword hardreg defs in INSN
    based on the bits in LIVE.  Do not generate notes for registers in
    artificial uses.  DO_NOT_GEN is updated so that REG_DEAD notes are
@@ -3728,7 +3754,6 @@ df_set_unused_notes_for_mw (rtx insn, rtx old, struct df_mw_hardreg *mws,
 			    bitmap live, bitmap do_not_gen, 
 			    bitmap artificial_uses)
 {
-  bool all_dead = true;
   unsigned int r;
   
 #ifdef REG_DEAD_DEBUGGING
@@ -3736,18 +3761,11 @@ df_set_unused_notes_for_mw (rtx insn, rtx old, struct df_mw_hardreg *mws,
     fprintf (dump_file, "mw_set_unused looking at mws[%d..%d]\n", 
 	     mws->start_regno, mws->end_regno);
 #endif
-  for (r=mws->start_regno; r <= mws->end_regno; r++)
-    if ((bitmap_bit_p (live, r))
-	|| bitmap_bit_p (artificial_uses, r))
-      {
-	all_dead = false;
-	break;
-      }
-  
-  if (all_dead)
+
+  if (df_whole_mw_reg_unused_p (mws, live, artificial_uses))
     {
       unsigned int regno = mws->start_regno;
-      old = df_set_note (REG_UNUSED, insn, old, *(mws->loc));
+      old = df_set_note (REG_UNUSED, insn, old, mws->mw_reg);
 
 #ifdef REG_DEAD_DEBUGGING
       df_print_note ("adding 1: ", insn, REG_NOTES (insn));
@@ -3772,6 +3790,34 @@ df_set_unused_notes_for_mw (rtx insn, rtx old, struct df_mw_hardreg *mws,
 }
 
 
+/* A subroutine of df_set_dead_notes_for_mw, with a selection of its
+   arguments.  Return true if the register value described by MWS's
+   mw_reg is known to be completely dead, and if mw_reg can therefore
+   be used in a REG_DEAD note.  */
+
+static bool
+df_whole_mw_reg_dead_p (struct df_mw_hardreg *mws,
+			bitmap live, bitmap artificial_uses,
+			bitmap do_not_gen)
+{
+  unsigned int r;
+
+  /* If MWS describes a partial reference, create REG_DEAD notes for
+     individual hard registers.  */
+  if (mws->flags & DF_REF_PARTIAL)
+    return false;
+
+  /* Likewise if some part of the register is not dead.  */
+  for (r = mws->start_regno; r <= mws->end_regno; r++)
+    if (bitmap_bit_p (live, r)
+	|| bitmap_bit_p (artificial_uses, r)
+	|| bitmap_bit_p (do_not_gen, r))
+      return false;
+
+  gcc_assert (REG_P (mws->mw_reg));
+  return true;
+}
+
 /* Set the REG_DEAD notes for the multiword hardreg use in INSN based
    on the bits in LIVE.  DO_NOT_GEN is used to keep REG_DEAD notes
    from being set if the instruction both reads and writes the
@@ -3782,7 +3828,6 @@ df_set_dead_notes_for_mw (rtx insn, rtx old, struct df_mw_hardreg *mws,
 			  bitmap live, bitmap do_not_gen,
 			  bitmap artificial_uses)
 {
-  bool all_dead = true;
   unsigned int r;
   
 #ifdef REG_DEAD_DEBUGGING
@@ -3798,25 +3843,13 @@ df_set_dead_notes_for_mw (rtx insn, rtx old, struct df_mw_hardreg *mws,
     }
 #endif
 
-  for (r = mws->start_regno; r <= mws->end_regno; r++)
-    if ((bitmap_bit_p (live, r))
-	|| bitmap_bit_p (artificial_uses, r)
-	|| bitmap_bit_p (do_not_gen, r))
-      {
-	all_dead = false;
-	break;
-      }
-  
-  if (all_dead)
+  if (df_whole_mw_reg_dead_p (mws, live, artificial_uses, do_not_gen))
     {
-      if (!bitmap_bit_p (do_not_gen, mws->start_regno))
-	{
-	  /* Add a dead note for the entire multi word register.  */
-	  old = df_set_note (REG_DEAD, insn, old, *(mws->loc));
+      /* Add a dead note for the entire multi word register.  */
+      old = df_set_note (REG_DEAD, insn, old, mws->mw_reg);
 #ifdef REG_DEAD_DEBUGGING
-	  df_print_note ("adding 1: ", insn, REG_NOTES (insn));
+      df_print_note ("adding 1: ", insn, REG_NOTES (insn));
 #endif
-	}
     }
   else
     {
diff --git a/gcc/df-scan.c b/gcc/df-scan.c
index acef3e4cb1f..6e622f8460d 100644
--- a/gcc/df-scan.c
+++ b/gcc/df-scan.c
@@ -2625,7 +2625,6 @@ df_ref_record (struct df_collection_rec *collection_rec,
 	       enum df_ref_type ref_type, 
 	       enum df_ref_flags ref_flags) 
 {
-  rtx oldreg = reg;
   unsigned int regno;
 
   gcc_assert (REG_P (reg) || GET_CODE (reg) == SUBREG);
@@ -2656,7 +2655,7 @@ df_ref_record (struct df_collection_rec *collection_rec,
 	{
 	  /* Sets to a subreg of a multiword register are partial. 
 	     Sets to a non-subreg of a multiword register are not.  */
-	  if (GET_CODE (oldreg) == SUBREG)
+	  if (GET_CODE (reg) == SUBREG)
 	    ref_flags |= DF_REF_PARTIAL;
 	  ref_flags |= DF_REF_MW_HARDREG;
 
@@ -2664,7 +2663,6 @@ df_ref_record (struct df_collection_rec *collection_rec,
 	  hardreg->type = ref_type;
 	  hardreg->flags = ref_flags;
 	  hardreg->mw_reg = reg;
-	  hardreg->loc = loc;
 	  hardreg->start_regno = regno;
 	  hardreg->end_regno = endregno - 1;
 	  hardreg->mw_order = df->ref_order++;
diff --git a/gcc/df.h b/gcc/df.h
index e4f2c099b13..77404317e58 100644
--- a/gcc/df.h
+++ b/gcc/df.h
@@ -311,7 +311,6 @@ struct dataflow
 struct df_mw_hardreg
 {
   rtx mw_reg;                   /* The multiword hardreg.  */ 
-  rtx *loc;			/* The location of the reg.  */
   enum df_ref_type type;        /* Used to see if the ref is read or write.  */
   enum df_ref_flags flags;	/* Various flags.  */
   unsigned int start_regno;     /* First word of the multi word subreg.  */