[llvm-commits] [llvm] r147765 - /llvm/trunk/lib/Target/X86/X86InstrSSE.td

[Jakob Stoklund Olesen]

On Jan 9, 2012, at 10:00 AM, Craig Topper wrote:

> Ordering seems to be maintained even for patterns declared with instructions and those wouldn't get an anonymous def would they?

See PatternSortingPredicate in DAGISelEmitter.cpp. The very last tie-breaker criterion is the Record ID, so that would be equivalent to source ordering.

It is very fragile to depend on this for correctness, it only kicks in when all the other criterions are identical.

I think it would be safer to use AddedComplexity.

/jakob