simplify-rtx.c (simplify_subreg): Adjust REG_OFFSET for big-endian paradoxical subregs.

* simplify-rtx.c (simplify_subreg): Adjust REG_OFFSET for
big-endian paradoxical subregs.
* var-tracking.c (struct micro_operation_def): Document that,
for modify micro operations, insn is the subsequent instruction.
(var_reg_delete_and_set, var_mem_delete_and_set): Split into...
(var_reg_set, var_mem_set): ... new functions.
(add_stores): Record subsequent insn.
(compute_bb_dataflow): Use new functions for MO_USE.
(emit_notes_in_bb): Use new functions for MO_USE.  Emit use
notes after the insn, and modify notes before the insn known
to be the subsequent one.
(vt_initialize): Invert sorting of MO_CLOBBERs and MO_SETs.

From-SVN: r114013

3 files changed, 98 insertions, 19 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4da9ce4..18c97a9 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,18 @@
+2006-05-23  Alexandre Oliva  <aoliva@redhat.com>
+
+	* simplify-rtx.c (simplify_subreg): Adjust REG_OFFSET for
+	big-endian paradoxical subregs.
+	* var-tracking.c (struct micro_operation_def): Document that,
+	for modify micro operations, insn is the subsequent instruction.
+	(var_reg_delete_and_set, var_mem_delete_and_set): Split into...
+	(var_reg_set, var_mem_set): ... new functions.
+	(add_stores): Record subsequent insn.
+	(compute_bb_dataflow): Use new functions for MO_USE.
+	(emit_notes_in_bb): Use new functions for MO_USE.  Emit use
+	notes after the insn, and modify notes before the insn known
+	to be the subsequent one.
+	(vt_initialize): Invert sorting of MO_CLOBBERs and MO_SETs.
+
 2006-05-23  Kazu Hirata  <kazu@codesourcery.com>
 
 	PR target/27696
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 6ab5cb7..7199316 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -4552,7 +4552,22 @@ simplify_subreg (enum machine_mode outermode, rtx op,
       if (HARD_REGNO_MODE_OK (final_regno, outermode)
 	  || ! HARD_REGNO_MODE_OK (regno, innermode))
 	{
-	  rtx x = gen_rtx_REG_offset (op, outermode, final_regno, byte);
+	  rtx x;
+	  int final_offset = byte;
+
+	  /* Adjust offset for paradoxical subregs.  */
+	  if (byte == 0
+	      && GET_MODE_SIZE (innermode) < GET_MODE_SIZE (outermode))
+	    {
+	      int difference = (GET_MODE_SIZE (innermode)
+				- GET_MODE_SIZE (outermode));
+	      if (WORDS_BIG_ENDIAN)
+		final_offset += (difference / UNITS_PER_WORD) * UNITS_PER_WORD;
+	      if (BYTES_BIG_ENDIAN)
+		final_offset += difference % UNITS_PER_WORD;
+	    }
+
+	  x = gen_rtx_REG_offset (op, outermode, final_regno, final_offset);
 
 	  /* Propagate original regno.  We don't have any way to specify
 	     the offset inside original regno, so do so only for lowpart.
diff --git a/gcc/var-tracking.c b/gcc/var-tracking.c
index 7e910d6..704d2f5 100644
--- a/gcc/var-tracking.c
+++ b/gcc/var-tracking.c
@@ -140,7 +140,11 @@ typedef struct micro_operation_def
     HOST_WIDE_INT adjust;
   } u;
 
-  /* The instruction which the micro operation is in.  */
+  /* The instruction which the micro operation is in, for MO_USE,
+     MO_USE_NO_VAR, MO_CALL and MO_ADJUST, or the subsequent
+     instruction or note in the original flow (before any var-tracking
+     notes are inserted, to simplify emission of notes), for MO_SET
+     and MO_CLOBBER.  */
   rtx insn;
 } micro_operation;
 
@@ -291,9 +295,11 @@ static void vars_clear (htab_t);
 static variable unshare_variable (dataflow_set *set, variable var);
 static int vars_copy_1 (void **, void *);
 static void vars_copy (htab_t, htab_t);
+static void var_reg_set (dataflow_set *, rtx);
 static void var_reg_delete_and_set (dataflow_set *, rtx);
 static void var_reg_delete (dataflow_set *, rtx);
 static void var_regno_delete (dataflow_set *, int);
+static void var_mem_set (dataflow_set *, rtx);
 static void var_mem_delete_and_set (dataflow_set *, rtx);
 static void var_mem_delete (dataflow_set *, rtx);
 
@@ -792,6 +798,19 @@ vars_copy (htab_t dst, htab_t src)
   htab_traverse (src, vars_copy_1, dst);
 }
 
+/* Set the register to contain REG_EXPR (LOC), REG_OFFSET (LOC).  */
+
+static void
+var_reg_set (dataflow_set *set, rtx loc)
+{
+  tree decl = REG_EXPR (loc);
+  HOST_WIDE_INT offset = REG_OFFSET (loc);
+
+  if (set->regs[REGNO (loc)] == NULL)
+    attrs_list_insert (&set->regs[REGNO (loc)], decl, offset, loc);
+  set_variable_part (set, loc, decl, offset);
+}
+
 /* Delete current content of register LOC in dataflow set SET
    and set the register to contain REG_EXPR (LOC), REG_OFFSET (LOC).  */
 
@@ -819,9 +838,7 @@ var_reg_delete_and_set (dataflow_set *set, rtx loc)
 	  nextp = &node->next;
 	}
     }
-  if (set->regs[REGNO (loc)] == NULL)
-    attrs_list_insert (&set->regs[REGNO (loc)], decl, offset, loc);
-  set_variable_part (set, loc, decl, offset);
+  var_reg_set (set, loc);
 }
 
 /* Delete current content of register LOC in dataflow set SET.  */
@@ -858,12 +875,12 @@ var_regno_delete (dataflow_set *set, int regno)
   *reg = NULL;
 }
 
-/* Delete and set the location part of variable MEM_EXPR (LOC)
-   in dataflow set SET to LOC.
+/* Set the location part of variable MEM_EXPR (LOC) in dataflow set
+   SET to LOC.
    Adjust the address first if it is stack pointer based.  */
 
 static void
-var_mem_delete_and_set (dataflow_set *set, rtx loc)
+var_mem_set (dataflow_set *set, rtx loc)
 {
   tree decl = MEM_EXPR (loc);
   HOST_WIDE_INT offset = MEM_OFFSET (loc) ? INTVAL (MEM_OFFSET (loc)) : 0;
@@ -871,6 +888,16 @@ var_mem_delete_and_set (dataflow_set *set, rtx loc)
   set_variable_part (set, loc, decl, offset);
 }
 
+/* Delete and set the location part of variable MEM_EXPR (LOC)
+   in dataflow set SET to LOC.
+   Adjust the address first if it is stack pointer based.  */
+
+static void
+var_mem_delete_and_set (dataflow_set *set, rtx loc)
+{
+  var_mem_set (set, loc);
+}
+
 /* Delete the location part LOC from dataflow set SET.
    Adjust the address first if it is stack pointer based.  */
 
@@ -1547,7 +1574,7 @@ add_stores (rtx loc, rtx expr, void *insn)
 		   && track_expr_p (REG_EXPR (loc)))
 		  ? MO_SET : MO_CLOBBER);
       mo->u.loc = loc;
-      mo->insn = (rtx) insn;
+      mo->insn = NEXT_INSN ((rtx) insn);
     }
   else if (MEM_P (loc)
 	   && MEM_EXPR (loc)
@@ -1558,7 +1585,7 @@ add_stores (rtx loc, rtx expr, void *insn)
 
       mo->type = GET_CODE (expr) == CLOBBER ? MO_CLOBBER : MO_SET;
       mo->u.loc = loc;
-      mo->insn = (rtx) insn;
+      mo->insn = NEXT_INSN ((rtx) insn);
     }
 }
 
@@ -1589,6 +1616,16 @@ compute_bb_dataflow (basic_block bb)
 	    break;
 
 	  case MO_USE:
+	    {
+	      rtx loc = VTI (bb)->mos[i].u.loc;
+
+	      if (GET_CODE (loc) == REG)
+		var_reg_set (out, loc);
+	      else if (GET_CODE (loc) == MEM)
+		var_mem_set (out, loc);
+	    }
+	    break;
+
 	  case MO_SET:
 	    {
 	      rtx loc = VTI (bb)->mos[i].u.loc;
@@ -2356,6 +2393,18 @@ emit_notes_in_bb (basic_block bb)
 	    break;
 
 	  case MO_USE:
+	    {
+	      rtx loc = VTI (bb)->mos[i].u.loc;
+
+	      if (GET_CODE (loc) == REG)
+		var_reg_set (&set, loc);
+	      else
+		var_mem_set (&set, loc);
+
+	      emit_notes_for_changes (insn, EMIT_NOTE_AFTER_INSN);
+	    }
+	    break;
+
 	  case MO_SET:
 	    {
 	      rtx loc = VTI (bb)->mos[i].u.loc;
@@ -2365,10 +2414,7 @@ emit_notes_in_bb (basic_block bb)
 	      else
 		var_mem_delete_and_set (&set, loc);
 
-	      if (VTI (bb)->mos[i].type == MO_USE)
-		emit_notes_for_changes (insn, EMIT_NOTE_BEFORE_INSN);
-	      else
-		emit_notes_for_changes (insn, EMIT_NOTE_AFTER_INSN);
+	      emit_notes_for_changes (insn, EMIT_NOTE_BEFORE_INSN);
 	    }
 	    break;
 
@@ -2383,9 +2429,9 @@ emit_notes_in_bb (basic_block bb)
 		var_mem_delete (&set, loc);
 
 	      if (VTI (bb)->mos[i].type == MO_USE_NO_VAR)
-		emit_notes_for_changes (insn, EMIT_NOTE_BEFORE_INSN);
-	      else
 		emit_notes_for_changes (insn, EMIT_NOTE_AFTER_INSN);
+	      else
+		emit_notes_for_changes (insn, EMIT_NOTE_BEFORE_INSN);
 	    }
 	    break;
 
@@ -2598,15 +2644,18 @@ vt_initialize (void)
 		}
 
 	      n1 = VTI (bb)->n_mos;
+	      /* This will record NEXT_INSN (insn), such that we can
+		 insert notes before it without worrying about any
+		 notes that MO_USEs might emit after the insn.  */
 	      note_stores (PATTERN (insn), add_stores, insn);
 	      n2 = VTI (bb)->n_mos - 1;
 
-	      /* Order the MO_SETs to be before MO_CLOBBERs.  */
+	      /* Order the MO_CLOBBERs to be before MO_SETs.  */
 	      while (n1 < n2)
 		{
-		  while (n1 < n2 && VTI (bb)->mos[n1].type == MO_SET)
+		  while (n1 < n2 && VTI (bb)->mos[n1].type == MO_CLOBBER)
 		    n1++;
-		  while (n1 < n2 && VTI (bb)->mos[n2].type == MO_CLOBBER)
+		  while (n1 < n2 && VTI (bb)->mos[n2].type == MO_SET)
 		    n2--;
 		  if (n1 < n2)
 		    {