I was trying to using llvm to targeting ARMv5TE
As you mention, the CPU arm7ej-s isn't in the ARM.td list, however it
is architecturally equivalent to some of the Arm9 cpus that support
the 5TE that are in ARM.td, for example the arm9e. If you used
-mcpu=arm9e you would get code generation that would work for the
arm7ej-s, as would using -march=armv5te. From a cursory look at the
technical reference manuals, there doesn't seem to be any significant
micro architectural differences that would change code-generation.