after installing the dependencies(mpfr, mpc, gmp, elf) of gcc. i was trying to go for gcc-4.5.1 with following commands as

../../Source/gcc-4.5.1/configure \
--build=$BUILDMACH \
--host=$BUILDMACH \
--target=$TARGETMACH \
--prefix=$INSTALLDIR \
--without-headers \
--enable-bootstrap \
--enable-languages=c \
--disable-threads \
--enable-__cxa_atexit \
--disable-libmudflap \
--with-gnu-ld \
--with-gnu-as \
--disable-libssp \
--disable-libgomp \
--disable-nls -\
-disable-shared \

It worked fine for me then

make all-gcc install-gcc

It also worked fine for me then
make all-target-libgcc install-target-libgcc

Here i am facing problem as
configure: error: cannot compute suffix of object files: cannot compile
See `config.log' for more details.
make: *** [configure-target-libgcc] Error 1

and after checking in the config.log file i found some thing like this:
configure:5858: gcc -c -g -O2 -I/home/phytectoolchain/Source/gcc-4.5.1/gmp/include -I/home/phytectoolchain/Source/gcc-4.5.1/mpfr/include -I/home/phytectoolchain/Source/gcc-4.5.1/mpc/include conftest.c >&5
conftest.c:10:19: fatal error: ppl_c.h: No such file or directory
compilation terminated.
.
.
.
configure:6074: result: gcc -E
configure:6094: gcc -E conftest.c
configure:6094: $? = 0
configure:6108: gcc -E conftest.c
conftest.c:10:28: fatal error: ac_nonexistent.h: No such file or directory

and many more. I also open my gmp folder and search for include directory but it was not there....
I am developing toolchain for ARM on 64-bit host and build machine

It might help to tell us what distro you're using. In any event it looks like you're missing some dev packages. Intalling the libppl0.12-dev package or whatever your distro calls it should solve the "fatal error: ppl_c.h: No such file or directory" problem.
jdk

i am using binutils-2.21.1a, linux-2.6.28.3, mpc-1.0.1, mpfr-3.0.1, gmp-4.3.2, libelf-0.8.13, gcc-4.5.1 so far and i have run the command that is given by you as
sudo apt-get install libppl0.12-dev
and i got an error as
E: Unable to locate package libppl0.12-dev
E: Couldn't find any package by regex 'libppl0.12-dev'

# 3 .
$ sudo apt-get update
$ apt-cache search libppl

$ sudo apt-get install <libppl??>
I.e. libppl0.12-dev is "Ubuntu 13.04 only".
The naming is different for different Ubuntu versions.

Please read post #2 : Which OS are you using ? ?
Finding your OS / version name : $ cat /etc/issue <Enter>
Or : $ cat /etc/*release* <Enter>

-

I am using Ubuntu 12.04.2
and today i had installed these packages
libppl-c4 - Parma Polyhedra Library (C interface)
libppl-doc - Parma Polyhedra Library: Documentation
libppl0.11-dev - Parma Polyhedra Library (development)
libppl9 - Parma Polyhedra Library (runtime library)
libpwl-dev - Parma Watchdog Library (Watchdog timers - development)
libpwl5 - Parma Watchdog Library (Watchdog timers - runtime library)


Let me check the tool chain process again so that i confirm that either it is working or not...Please give me some time