[PATCH 07/50] combine.c:record_truncated_values

[Richard Sandiford]

gcc/
        * combine.c (record_truncated_value): Turn from being a for_each_rtx
        callback to a function that takes an rtx and returns a bool
        (record_truncated_values): Use FOR_EACH_SUBRTX_VAR instead of
        for_each_rtx.

Index: gcc/combine.c
===================================================================
--- gcc/combine.c       2014-08-03 11:25:21.711070825 +0100
+++ gcc/combine.c       2014-08-03 11:25:22.005073732 +0100
@@ -469,7 +469,6 @@ static void distribute_links (struct ins
 static void mark_used_regs_combine (rtx);
 static void record_promoted_value (rtx, rtx);
 static bool unmentioned_reg_p (rtx, rtx);
-static int record_truncated_value (rtx *, void *);
 static void record_truncated_values (rtx *, void *);
 static bool reg_truncated_to_mode (enum machine_mode, const_rtx);
 static rtx gen_lowpart_or_truncate (enum machine_mode, rtx);
@@ -12493,15 +12492,14 @@ reg_truncated_to_mode (enum machine_mode
   return false;
 }
 
-/* Callback for for_each_rtx.  If *P is a hard reg or a subreg record the mode
-   that the register is accessed in.  For non-TRULY_NOOP_TRUNCATION targets we
-   might be able to turn a truncate into a subreg using this information.
-   Return -1 if traversing *P is complete or 0 otherwise.  */
+/* If X is a hard reg or a subreg record the mode that the register is
+   accessed in.  For non-TRULY_NOOP_TRUNCATION targets we might be able
+   to turn a truncate into a subreg using this information.  Return true
+   if traversing X is complete.  */
 
-static int
-record_truncated_value (rtx *p, void *data ATTRIBUTE_UNUSED)
+static bool
+record_truncated_value (rtx x)
 {
-  rtx x = *p;
   enum machine_mode truncated_mode;
   reg_stat_type *rsp;
 
@@ -12511,10 +12509,10 @@ record_truncated_value (rtx *p, void *da
       truncated_mode = GET_MODE (x);
 
       if (GET_MODE_SIZE (original_mode) <= GET_MODE_SIZE (truncated_mode))
-       return -1;
+       return true;
 
       if (TRULY_NOOP_TRUNCATION_MODES_P (truncated_mode, original_mode))
-       return -1;
+       return true;
 
       x = SUBREG_REG (x);
     }
@@ -12523,7 +12521,7 @@ record_truncated_value (rtx *p, void *da
   else if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
     truncated_mode = GET_MODE (x);
   else
-    return 0;
+    return false;
 
   rsp = &reg_stat[REGNO (x)];
   if (rsp->truncated_to_mode == 0
@@ -12535,7 +12533,7 @@ record_truncated_value (rtx *p, void *da
       rsp->truncation_label = label_tick;
     }
 
-  return -1;
+  return true;
 }
 
 /* Callback for note_uses.  Find hardregs and subregs of pseudos and
@@ -12543,9 +12541,12 @@ record_truncated_value (rtx *p, void *da
    SUBREGs.  */
 
 static void
-record_truncated_values (rtx *x, void *data ATTRIBUTE_UNUSED)
+record_truncated_values (rtx *loc, void *data ATTRIBUTE_UNUSED)
 {
-  for_each_rtx (x, record_truncated_value, NULL);
+  subrtx_var_iterator::array_type array;
+  FOR_EACH_SUBRTX_VAR (iter, array, *loc, NONCONST)
+    if (record_truncated_value (*iter))
+      iter.skip_subrtxes ();
 }
 
 /* Scan X for promoted SUBREGs.  For each one found,