[x86] Expand the target DAG combining for PSHUFD nodes to be able to
combine into half-shuffles through unpack instructions that expand the
half to a whole vector without messing with the dword lanes.

This fixes some redundant instructions in splat-like lowerings for
v16i8, which are now getting to be *really* nice.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212695 91177308-0d34-0410-b5e6-96231b3b80d8
Make it possible for ints/floats to return different values from getBooleanContents()

Summary:
On MIPS32r6/MIPS64r6, floating point comparisons return 0 or -1 but integer
comparisons return 0 or 1.

Updated the various uses of getBooleanContents. Two simplifications had to be
disabled when float and int boolean contents differ:
- ScalarizeVecRes_VSELECT except when the kind of boolean contents is trivially
  discoverable (i.e. when the condition of the VSELECT is a SETCC node).
- visitVSELECT (select C, 0, 1) -> (xor C, 1).
  Come to think of it, this one could test for the common case of 'C'
  being a SETCC too.

Preserved existing behaviour for all other targets and updated the affected
MIPS32r6/MIPS64r6 tests. This also fixes the pi benchmark where the 'low'
variable was counting in the wrong direction because it thought it could simply
add the result of the comparison.

Reviewers: hfinkel

Reviewed By: hfinkel

Subscribers: hfinkel, jholewinski, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D4389


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212697 91177308-0d34-0410-b5e6-96231b3b80d8
[SystemZ] Fix FPR dwarf numbering

The dwarf FPR numbers are supposed to have the order F0, F2, F4, F6,
F1, F3, F5, F7, F8, etc., which matches the pairing of registers for
long doubles.  E.g. a long double stored in F0 is paired with F2.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212701 91177308-0d34-0410-b5e6-96231b3b80d8