The two separate dynamic linker programs for 32-bit applications and for 64-bit applications are: /usr/lib/ld.so.1 and /usr/lib/sparcv9/ld.so.1.
At runtime, both dynamic linkers search the same list of colon-separated directories specified by the LD_LIBRARY_PATH environment variable. However, the 32-bit dynamic linker binds only to 32-bit libraries, while the 64-bit dynamic linker binds only to 64-bit libraries. So directories containing both 32-bit and 64-bit libraries can be specified via LD_LIBRARY_PATH, if needed.
The 64-bit dynamic linker's search path can be completely overridden using the LD_LIBRARY_PATH_64 environment variable.