<rdar://problem/6721894>. Allow multiple registers to be renamed together (super and sub) if necessary to break an anti-dependence.

llvm-svn: 89722

llvm-svn: 89511

Remove some old experimental code that is no longer needed. Remove additional, speculative scheduling pass as its cost did not translate into significant performance improvement. Minor tweaks.

llvm-svn: 89471

llvm-svn: 89404

llvm-svn: 88682

llvm-svn: 87015

Allow targets to specify register classes whose member registers should not be renamed to break anti-dependencies. 

llvm-svn: 86628

Fix bug in aggressive antidep breaking; liveness was not updated correctly for regions that do not have antidep candidates.

llvm-svn: 86172

llvm-svn: 86102

Break anti-dependencies using free registers in a round-robin manner to avoid introducing new anti-dependencies.

llvm-svn: 86098

Do a scheduling pass ignoring anti-dependencies to identify candidate registers that should be renamed.

llvm-svn: 85939

Between scheduling regions, correctly maintain anti-dep breaking state so that we don't incorrectly rename registers that span these regions.

llvm-svn: 85537

llvm-svn: 85522

Allow the aggressive anti-dep breaker to process the same region multiple times. This is necessary because new anti-dependencies are exposed when "current" ones are broken.

llvm-svn: 85166

Add aggressive anti-dependence breaker. Currently it is not the default for any target. Enable with -break-anti-dependencies=all.

llvm-svn: 85145