[mep] RFA: Use new rtl iterators in global_reg_mentioned_p

[Richard Sandiford <rdsandiford at googlemail dot com>]

This is part of a series to remove uses of for_each_rtx from the ports.
The cases:

    case SCRATCH:
    case PC:
    case CC0:
    case CONST_INT:
    case CONST_DOUBLE:
    case CONST:
    case LABEL_REF:

were just short-cuts to avoid looking through unnecessary subrtxes.
SCRATCH, PC and CC0 don't have subrtxes, so keeping the cases would
add rather than remove work when using the new iterator.  The other
cases are handled by the NONCONST argument to FOR_EACH_SUBRTX.

Tested by making sure there were no code changes for gcc.dg, gcc.c-torture
and g++.dg for mep-elf.  OK to install?

Thanks,
Richard


gcc/
	* config/mep/mep.c: Include rtl-iter.h.
	(global_reg_mentioned_p_1): Take a const_rtx and return a bool.
	(xtensa_tls_referenced_p): Return a bool.  Use FOR_EACH_SUBRTX.

Index: gcc/config/mep/mep.c
===================================================================
--- gcc/config/mep/mep.c	2014-10-25 09:48:52.837535660 +0100
+++ gcc/config/mep/mep.c	2014-10-25 09:51:18.001817191 +0100
@@ -69,6 +69,7 @@ Software Foundation; either version 3, o
 #include "opts.h"
 #include "dumpfile.h"
 #include "builtins.h"
+#include "rtl-iter.h"
 
 /* Structure of this file:
 
@@ -6367,14 +6368,10 @@ mep_vector_mode_supported_p (enum machin
 /* A subroutine of global_reg_mentioned_p, returns 1 if *LOC mentions
    a global register.  */
 
-static int
-global_reg_mentioned_p_1 (rtx *loc, void *data ATTRIBUTE_UNUSED)
+static bool
+global_reg_mentioned_p_1 (const_rtx x)
 {
   int regno;
-  rtx x = *loc;
-
-  if (! x)
-    return 0;
 
   switch (GET_CODE (x))
     {
@@ -6383,40 +6380,31 @@ global_reg_mentioned_p_1 (rtx *loc, void
 	{
 	  if (REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER
 	      && global_regs[subreg_regno (x)])
-	    return 1;
-	  return 0;
+	    return true;
+	  return false;
 	}
       break;
 
     case REG:
       regno = REGNO (x);
       if (regno < FIRST_PSEUDO_REGISTER && global_regs[regno])
-	return 1;
-      return 0;
-
-    case SCRATCH:
-    case PC:
-    case CC0:
-    case CONST_INT:
-    case CONST_DOUBLE:
-    case CONST:
-    case LABEL_REF:
-      return 0;
+	return true;
+      return false;
 
     case CALL:
       /* A non-constant call might use a global register.  */
-      return 1;
+      return true;
 
     default:
       break;
     }
 
-  return 0;
+  return false;
 }
 
 /* Returns nonzero if X mentions a global register.  */
 
-static int
+static bool
 global_reg_mentioned_p (rtx x)
 {
   if (INSN_P (x))
@@ -6424,16 +6412,20 @@ global_reg_mentioned_p (rtx x)
       if (CALL_P (x))
 	{
 	  if (! RTL_CONST_OR_PURE_CALL_P (x))
-	    return 1;
+	    return true;
 	  x = CALL_INSN_FUNCTION_USAGE (x);
 	  if (x == 0)
-	    return 0;
+	    return false;
 	}
       else
 	x = PATTERN (x);
     }
 
-  return for_each_rtx (&x, global_reg_mentioned_p_1, NULL);
+  subrtx_iterator::array_type array;
+  FOR_EACH_SUBRTX (iter, array, x, NONCONST)
+    if (global_reg_mentioned_p_1 (*iter))
+      return true;
+  return false;
 }
 /* Scheduling hooks for VLIW mode.