Perform factorization as a last resort of unsafe fadd/fsub simplification.

Rules include:
  1)1 x*y +/- x*z => x*(y +/- z) 
    (the order of operands dosen't matter)

  2) y/x +/- z/x => (y +/- z)/x 

 The transformation is disabled if the new add/sub expr "y +/- z" is a 
denormal/naz/inifinity.

rdar://12911472


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177088 91177308-0d34-0410-b5e6-96231b3b80d8
[mips] Define two subclasses of MipsDAGToDAGISel. Mips16DAGToDAGISel is for
mips16 and MipsSEDAGToDAGISel is for mips32/64. 

No functionality changes.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177089 91177308-0d34-0410-b5e6-96231b3b80d8
Add header file MipsISelDAGToDAG.h.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177090 91177308-0d34-0410-b5e6-96231b3b80d8
[mips] Rename functions and variables to start with proper case.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177092 91177308-0d34-0410-b5e6-96231b3b80d8
Add a comment about overlapping PPC frame offsets

I don't think that it is otherwise clear how the overlapping offsets
are processed into distinct spill slots. Comment that this is done
in processFunctionBeforeFrameFinalized.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177094 91177308-0d34-0410-b5e6-96231b3b80d8
[mips] Define function MipsSEDAGToDAGISel::selectAddESubE.

No intended functionality changes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177095 91177308-0d34-0410-b5e6-96231b3b80d8
Add back lines which were accidentally deleted in CMakeLists.txt.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177096 91177308-0d34-0410-b5e6-96231b3b80d8
LoopVectorize: Invert case when we use a vector cmp value to query select cost

We generate a select with a vectorized condition argument when the condition is
NOT loop invariant. Not the other way around.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177098 91177308-0d34-0410-b5e6-96231b3b80d8