Porting problem from GCC-4.0 to GCC 4.1

[Shrirang Khishti]

Hi all
   I have ported GCC-4.0 for a new target. Initially I started porting
with GCC-3.4 and then shifted to GCC-4.0 without any problems. Now I
want to port same code for GCC-4.1 . As there are some structural
differences in GCC-4.0 and gcc-4.1 back-ends specially regarding
addition of .opt file. I have removed all the macros related to
TARGET_SWITCHES and made appropriate entries in .opt file. With this and
some other changes I build cc1. I have also updated TARGET_DEFAULT macro
in target.h file.  But problem that I found is that if I don't specify
any target specific option target_flags are remaining zero. They are not
getting set as expected for DEFAULT_TARGET and so it is giving me ICE.
   If I explicitly give target specific option which is on DEFAULT, then
I am not having any problems.
   Anything is missing from my side? 
Any help will be appreciated

Thanking in advance
Regards

Shrirang Khisti 
KPIT Cummins Infosystems Ltd.