53 Commits

Author	SHA1	Message	Date
Chris Lattner	4d52e1e401	After unrolling our single basic block loop, fold it into the preheader and exit ... block. The primary motivation for doing this is that we can now unroll nested loops. This makes a pretty big difference in some cases. For example, in 183.equake, we are now beating the native compiler with the CBE, and we are a lot closer with LLC. I'm now going to play around a bit with the unroll factor and see what effect it really has. llvm-svn: 13034	2004-04-18 06:27:43 +00:00
Chris Lattner	f2cc841619	Fix a bug: this does not preserve the CFG! ... While we're at it, add support for updating loop information correctly. llvm-svn: 13033	2004-04-18 05:38:37 +00:00
Chris Lattner	946b255977	Initial checkin of a simple loop unroller. This pass is extremely basic and ... limited. Even in it's extremely simple state (it can only *fully* unroll single basic block loops that execute a constant number of times), it already helps improve performance a LOT on some benchmarks, particularly with the native code generators. llvm-svn: 13028	2004-04-18 05:20:17 +00:00