CONFIG_SPARC32_COMPAT is not available for thedefaultarchitecture x86.
Result is shown for architecture sparc64

Kernel support for Linux/Sparc 32bit binary compatibility

modulename: sys32.ko

configname: CONFIG_SPARC32_COMPAT

Linux/UltraSPARC Kernel Configuration
└─>General machine setup
└─>Kernel support for Linux/Sparc 32bit binary compatibility
In linux kernel since version 2.6.12  
This allows you to run 32-bit binaries on your Ultra.
Everybody wants this; say Y.

source code: