For ISD::EXTRACT_SUBVECTOR, its second operand must be a constant
multiple of the known-minimum vector length of the result type.
Reviewed By: dmgreen
Differential Revision: https://reviews.llvm.org/D107795
The loops are run exactly once per lane, so VGPRs do not need to be
saved. Use the SIOptimizeVGPRLiveRange pass to add phi nodes that take
undef when coming from the loop.
There is still a shortcoming:
Return values from a function call in the loop are copied because their
live range conflicts with the live range of arguments, even if arguments
are only IMPLICIT_DEF after the phi insertion.
Differential Revision: https://reviews.llvm.org/D105192
In this particular example, we had a crash when compiling it
for several architectures. This patch extends the legalization
of extract_subvector to avoid this problem.
Differential Revision: https://reviews.llvm.org/D103344
