CONFIG_ISA_ARCOMPACT is not available for thedefaultarchitecture x86.
Result is shown for architecture arc
ARCompact ISA
modulename: entry-compact.ko
configname: CONFIG_ISA_ARCOMPACT
ARC Instruction Set
└─>ARCompact ISA
In linux kernel since version 3.10 (release Date: 2013-06-30)
The original ARC ISA of ARC600/700 cores