Exit loop analysis early if suitable private access found.
Do not account for GEPs which are invariant to loop induction variable.
Do not account for Allocas which are too big to fit into register file anyway.
Add option for tuning: -amdgpu-unroll-threshold-private.
Differential Revision: https://reviews.llvm.org/D29473
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293991 91177308-0d34-0410-b5e6-96231b3b80d8
noduplicate prevents unrolling of small loops that happen to have
barriers in them. If a loop has a barrier in it, it is OK to duplicate
it for the unroll.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256075 91177308-0d34-0410-b5e6-96231b3b80d8
