dwarf2out.c (rtl_for_decl_location): Adjust rtl for byte variables stored in…

dwarf2out.c (rtl_for_decl_location): Adjust rtl for byte variables stored in word registers, then in memory.

* dwarf2out.c (rtl_for_decl_location): Adjust rtl for byte
variables stored in word registers, then in memory.

From-SVN: r80941

gcc/ChangeLog

+2004-04-20  DJ Delorie  <dj@redhat.com>
+	
+	* dwarf2out.c (rtl_for_decl_location): Adjust rtl for byte
+	variables stored in word registers, then in memory.
+
 2004-04-20  Eric Christopher  <echristo@redhat.com>
 
 	* cp/parser.c (cp_parser_declaration): Move translate

gcc/dwarf2out.c

@@ -9756,6 +9756,24 @@ rtl_for_decl_location (tree decl)
 			     plus_constant (XEXP (rtl, 0), offset));
 	}
     }
+  else if (TREE_CODE (decl) == VAR_DECL
+	   && GET_CODE (rtl) == MEM
+	   && GET_MODE (rtl) != TYPE_MODE (TREE_TYPE (decl))
+	   && BYTES_BIG_ENDIAN)
+    {
+      int rsize = GET_MODE_SIZE (GET_MODE (rtl));
+      int dsize = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (decl)));
+
+      /* If a variable is declared "register" yet is smaller than
+	 a register, then if we store the variable to memory, it
+	 looks like we're storing a register-sized value, when in
+	 fact we are not.  We need to adjust the offset of the
+	 storage location to reflect the actual value's bytes,
+	 else gdb will not be able to display it.  */
+      if (rsize > dsize)
+	rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (decl)),
+			   plus_constant (XEXP (rtl, 0), rsize-dsize));
+    }
 
   if (rtl != NULL_RTX)
     {