tree 47df2dcd2aebc3047a5bfc89243a8f6ec3037116
parent 9c0c7f0975ae3b25aca17067ec2e14a3e9192e76
author David Green <david.green@arm.com> 1616690655 +0000
committer Copybara-Service <copybara-worker@google.com> 1616712600 -0700

[ARM] Revert WhileLoopStartLR to DoLoopStart

If a WhileLoopStartLR is reverted due to calls in the preheader, we may
still be able to instead create a DoLoopStart, preserving the low
overhead loop. This adds code for that, only reverting the
WhileLoopStartR to a Br/Cmp, leaving the rest of the low overhead loop
in place.

Differential Revision: https://reviews.llvm.org/D98413

GitOrigin-RevId: d97189600e26553fa4fcdc73bd66b22c0ea420dd