Below is the file 'misc/config/arch/ia32' from this revision. You can also download the file.

realname "IA-32"

default_submodel i686

endian little
unaligned ok

<aliases>
x86
ix86
80x86
i86pc # for Solaris
</aliases>

<submodels>
i386
i486
i586
i686
pentium4
k6
athlon
</submodels>

<submodel_aliases>
pentium -> i586
pentiumpro -> i686
pentium_pro -> i686
pentium2 -> i686
pentium3 -> i686

duron -> athlon
athlon-xp -> athlon
k7 -> athlon

p2 -> i686
p3 -> i686
p4 -> pentium4
</submodel_aliases>