1.firstly,i compile the binutils-2.15, it successed. ../configure -target=rs6000-ibm-aix4.3 -prefix=/opt/crosstools/ make make install 2.secondly, i compile the gcc ../configure -target=rs6000-ibm-aix4.3 -prefix=/opt/crosstools/ -enable-languages=c make then it failed as follows: ../../../source/gcc-4.0-20050109/gcc/config/rs6000/darwin.md:243: unknown mode `V4SI' i try to delete the lines that make errors, but when it start to compile the gcc, it will error again. thank you.