How can I get a list of legal ARM opcodes from gcc (or elsewhere)? -

I want to generate pseudo random ARM instructions. Through the assembler instructions, I can tell the GCC what mode I am in, and if I try to set a set of opencodes and operators who are not legally in that mode then this will complain, so some internal list Which mode can be done in which mode. Where do they live? Will it be easier to remove that information from LLVM?

Is this question "not wrong"? Should I try a completely different approach?

To answer my own question, it's really easy to do GMC / Config / Arm / In arm and MD and obstacles. Perhaps I used to spend more time answering this question and answering comments for it, I figured it out. On exit, I need to look 'TARGET_THUMB1', until I get to apply thumb 2.