Linux seems to have 3/4/5/686.

bmomjian · bmomjian · commit f05642bbccaa · 1997-09-16T18:51:49.000Z
diff --git a/src/template/.similar b/src/template/.similar
@@ -7,6 +7,9 @@ i386-unknown-netbsd=netbsd
 i586-pc-sco3.2v=sco
 mips-sgi-irix=irix
 sparc-sun-solaris=sparc_solaris-gcc
-i585-pc-linux-gnu=linux-elf
+i386-pc-linux-gnu=linux-elf
+i486-pc-linux-gnu=linux-elf
+i586-pc-linux-gnu=linux-elf
+i686-pc-linux-gnu=linux-elf
 sparc-unknown-linux-gnu=linux-elf
 alpha-unknown-linux-gnu=linuxalpha
