[LLVMdev] About instrumenting/rewriting X86 instructions

[guitarfeng]

Hi all,

I plan to use LLVM to instrument/rewrite X86 instructions during the
compilation of a program.
For example, insert checking target instructions before jmp
instructions, or rewrite a instruction to prevent code using a specific
register.

I think the work should be done at the CodeGen phase, but I'm not quite
clear how can I start.
Can anyone give me some suggestion?

Thanks very much,
Zf