cpp-i686-linux-gnu 4:7.3.0-3ubuntu2.1 (amd64 binary) in ubuntu bionic

 The GNU C preprocessor is a macro processor that is used automatically
 by the GNU C compiler to transform programs before actual compilation.
 .
 This package has been separated from gcc for the benefit of those who
 require the preprocessor but not the cross-compiler for i386 architecture.
 .
 This is a dependency package providing the default GNU C preprocessor
 for the i386 architecture.