1b640e05ba
This patch adds support for the MachO .alt_entry assembly directive, and uses it for global aliases with non-zero GEP offsets. The alt_entry flag indicates that a symbol should be layed out immediately after the preceding symbol. Conceptually it introduces an alternate entry point for a function or data structure. E.g.: safe_foo: // check preconditions for foo .alt_entry fast_foo fast_foo: // body of foo, can assume preconditions. The .alt_entry flag is also implicitly set on assembly aliases of the form: a = b + C where C is a non-zero constant, since these have the same effect as an alt_entry symbol: they introduce a label that cannot be moved relative to the preceding one. Setting the alt_entry flag on aliases of this form fixes http://llvm.org/PR25381. llvm-svn: 263521