This function will find the closest ref node aliased to Reg that is
in an instruction preceding Inst. This could be used to identify the
hypothetical reaching def of Reg, if Reg was a member of Inst.
llvm-svn: 297524
This required reengineering of some of the part of liveness calculation,
including fixing some issues caused by the limitations of the previous
approach. The current code is not necessarily the fastest, but it should
be functionally correct (at least more so than before). The compile-time
performance will be addressed in the future.
llvm-svn: 284609
Use PackedRegisterRef to store the register information in the graph nodes.
This commit also removes support for virtual registers. It has never been
tested or used. It will be possible to add it back if there is a need.
llvm-svn: 284255
Shadow uses need to be analyzed together, since each individual shadow
will only have a partial reaching def. All shadows together may cover
a given register ref, while each individual shadow may not.
llvm-svn: 280855