give instcombine some helper functions for matching MIN and MAX, and
implement some optimizations for MIN(MIN()) and MAX(MAX()) and 
MIN(MAX()) etc.  This substantially improves the code in PR5822 but
doesn't kick in much elsewhere.  2 max's were optimized in 
pairlocalalign and one in smg2000.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91814 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed