regcprop.c (maybe_mode_change): Check HARD_REGNO_MODE_OK.

gcc/
	* regcprop.c (maybe_mode_change): Check HARD_REGNO_MODE_OK.

From-SVN: r176558

gcc/ChangeLog

+2011-07-21  Richard Sandiford  <richard.sandiford@linaro.org>
+
+	* regcprop.c (maybe_mode_change): Check HARD_REGNO_MODE_OK.
+
 2011-07-21  Kai Tietz  <ktietz@redhat.com>
 
 	* tree-ssa-propagate.c (substitute_and_fold): Use

gcc/regcprop.c

@@ -418,10 +418,9 @@ maybe_mode_change (enum machine_mode orig_mode, enum machine_mode copy_mode,
 
       offset = ((WORDS_BIG_ENDIAN ? wordoffset : 0)
 		+ (BYTES_BIG_ENDIAN ? byteoffset : 0));
-      return gen_rtx_raw_REG (new_mode,
-			      regno + subreg_regno_offset (regno, orig_mode,
-							   offset,
-							   new_mode));
+      regno += subreg_regno_offset (regno, orig_mode, offset, new_mode);
+      if (HARD_REGNO_MODE_OK (regno, new_mode))
+	return gen_rtx_raw_REG (new_mode, regno);
     }
   return NULL_RTX;
 }