search for: ppc_thread_pointer

...nted in terms of address space (similar to getStackCooikeLocation), but on AArch64 it's implemented in terms of a target specific AArch64ISD::THREAD_POINTER and Intrinsic::aarch64_thread_pointer. To make the fix least surprising, I can either do: 1) Create PPCISD::THREAD_POINTER and Intrinsic::ppc_thread_pointer and do similar things aarch64 does; or 2) Don't create PPCISD::THREAD_POINTER, but directly calls llvm.read_register intrinsic in ppc's getStackCookieLocation(). This is the way that requires least change; or 3) Create a generic ISD::GET_GLOBAL_TLS_ADDRESS and intrinsic llvm.get_global_tls_...

I found a bit weird to use address space for this, since the offset of getting stack_guard in TCB is, unfortunately, negative: https://github.com/gcc-mirror/gcc/blob/master/gcc/config/rs6000/linux64.h#L610 In my understanding an address space is referring to a segment register (-on powerpc 32bit; or SLB entry on powerpc 64bit?) with a non-negative offset value, so that it's actually accessing