rtlhooks.c (gen_lowpart_if_possible): Check for invalid subreg before calling gen_lowpart_SUBREG.

2007-07-02  Andrew Pinski  <andrew_pinski@playstation.sony.com>

        * rtlhooks.c (gen_lowpart_if_possible): Check for
        invalid subreg before calling gen_lowpart_SUBREG.

From-SVN: r126230

gcc/ChangeLog

+2007-07-02  Andrew Pinski  <andrew_pinski@playstation.sony.com>
+
+	* rtlhooks.c (gen_lowpart_if_possible): Check for
+	invalid subreg before calling gen_lowpart_SUBREG.
+
 2007-07-02  Geoffrey Keating  <geoffk@apple.com>
 
 	* config/darwin9.h: Add copyright notice.

gcc/rtlhooks.c

@@ -161,7 +161,9 @@ gen_lowpart_if_possible (enum machine_mode mode, rtx x)
 
       return new;
     }
-  else if (mode != GET_MODE (x) && GET_MODE (x) != VOIDmode)
+  else if (mode != GET_MODE (x) && GET_MODE (x) != VOIDmode
+	   && validate_subreg (mode, GET_MODE (x), x,
+			        subreg_lowpart_offset (mode, GET_MODE (x))))
     return gen_lowpart_SUBREG (mode, x);
   else
     return 0;