commit cb52932bbf6c40e612c70f30138b025485c0de77
author Shiva Chen <shiva0217@gmail.com> Fri Jan 18 08:36:06 2019 +0000
committer Shiva Chen <shiva0217@gmail.com> Fri Jan 18 08:36:06 2019 +0000
tree 25062b666d05eea95f52c6bbd6907ac3acdacf42
parent c3d9898b085b88aad94e54fe43db544c47c2f161

[ScheduleDAGRRList] Do not preschedule the node has ADJCALLSTACKDOWN parent

We should not pre-scheduled the node has ADJCALLSTACKDOWN parent,
or else, when bottom-up scheduling, ADJCALLSTACKDOWN and
ADJCALLSTACKUP may hold CallResource too long and make other
calls can't be scheduled. If there's no other available node
to schedule, the scheduler will try to rename the register by
creating copy to avoid the conflict which will fail because
CallResource is not a real physical register.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351527 91177308-0d34-0410-b5e6-96231b3b80d8