https://gcc.gnu.org/bugzilla/show_bug.cgi?id=24943
--- Comment #9 from dave.anglin at bell dot net --- The problem is there isn't a fixed relationship between the stack pointer register, %r30, and the argument pointer register, %r29. HP didn't provide a slot in the stack frame to save the argument pointer. It is call clobbered. The only option to fix this issue would be be to preserve it across calls. This would impact performance.
