[libc-commits] [libc] [libc][ARM] Defend banked SP setup against register allocator (PR #206757)

[Simon Tatham via libc-commits]

statham-arm wrote:

Depends what you mean by "in practice". As I say in the commit message, it did happen to me – clang code-generated this function in a way that failed at run time because of  running `msr cpsr_c,lr` which loaded from the wrong LR. But it was in the context of running the libc tests on a model in a not-yet-committed change to the downstream Arm Toolchain, not in "live" code that anyone was trying to use to do something useful.

https://github.com/llvm/llvm-project/pull/206757