On PowerPC, VSRpRC represents the pairs of even and odd VSX register,
and VRRC corresponds to higher 32 VSX registers. In some cases, extra
copies are produced when handling incoming VRRC arguments with VSRpRC.
This patch changes allocation order of VSRpRC to eliminate this kind of
copy.
Stack frame sizes may increase if allocating non-volatile registers, and
some other vector copies happen. They need fix in future changes.
Reviewed By: nemanjai
Differential Revision: https://reviews.llvm.org/D104855
We have added STXVP/LXVP for spilling and restoring the registers
but we neglected to add FI elimination code for these. The result
is that we end up producing impossible MachineInstr's that have
register operands in place of immediates.
