1Pull in r199186 from upstream llvm trunk (by Jakob Stoklund Olesen):
2
3  Switch the NEON register class from QPR to DPair.
4
5  The already allocatable DPair superclass contains odd-even D register
6  pair in addition to the even-odd pairs in the QPR register class. There
7  is no reason to constrain the set of D register pairs that can be used
8  for NEON values. Any NEON instructions that require a Q register will
9  automatically constrain the register class to QPR.
10
11  The allocation order for DPair begins with the QPR registers, so
12  register allocation is unlikely to change much.
13
14Introduced here: http://svn.freebsd.org/changeset/base/262261
15
16Index: lib/Target/ARM/ARMISelLowering.cpp
17===================================================================
18--- lib/Target/ARM/ARMISelLowering.cpp
19+++ lib/Target/ARM/ARMISelLowering.cpp
20@@ -156,7 +156,7 @@ void ARMTargetLowering::addDRTypeForNEON(MVT VT) {
21 }
22 
23 void ARMTargetLowering::addQRTypeForNEON(MVT VT) {
24-  addRegisterClass(VT, &ARM::QPRRegClass);
25+  addRegisterClass(VT, &ARM::DPairRegClass);
26   addTypeForNEON(VT, MVT::v2f64, MVT::v4i32);
27 }
28 
29