Jakob Stoklund Olesen 448ab3ab39 Avoid calling TRI->getAllocatableSet in RAFast.
When compiling a program with lots of small functions like
483.xalancbmk, this makes RAFast 11% faster.

Add some comments to clarify the difference between unallocatable and
reserved registers. It's quite subtle.

The fast register allocator depends on EFLAGS' not being allocatable on
x86. That way it can completely avoid tracking liveness, and it won't
mind when there are multiple uses of a single def.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132514 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-02 23:41:40 +00:00
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2011-05-26 18:59:54 +00:00
2011-03-12 22:01:42 +00:00
2010-11-15 03:21:41 +00:00