On Solaris (version 2.1), do not use the linker or other tools in
`/usr/ucb' to build GNU CC. Use /usr/ccs/bin.
Make sure the environment variable FLOAT_OPTION is not set when
you compile `libgcc.a'. If this option were set to f68881
when `libgcc.a' is compiled, the resulting code would demand to be
linked with a special startup file and would not link properly without
special pains.
There is a bug in alloca in certain versions of the Sun library.
To avoid this bug, install the binaries of GNU CC that were compiled by
GNU CC. They use alloca as a built-in function and never the one
in the library.
Some versions of the Sun compiler crash when compiling GNU CC. The problem is a segmentation fault in cpp. This problem seems to be due to the bulk of data in the environment variables. You may be able to avoid it by using the following command to compile GNU CC with Sun CC:
make CC="TERMCAP=x OBJS=x LIBFUNCS=x STAGESTUFF=x cc"