[AMDGPU] Ignore non-SUnits edges
Summary:
Ignore edges to non-SUnits (e.g. ExitSU) when checking
for low latency instructions.
When calling the function isLowLatencyInstruction(),
an ExitSU could be on the list of successors, not necessarily
a regular SU. In other places in the code there is a check
"Succ->NodeNum >= DAGSize" to prevent further processing of
ExitSU as "Succ->getInstr()" is NULL in such a case.
Also, 8 out of 9 cases of "SUnit *Succ = SuccDep.getSUnit())"
has the guard, so it is clearly an omission here.
Change-Id: Ica86f0327c7b2e6bcb56958e804ea6c71084663b
Reviewers: nhaehnle
Reviewed By: nhaehnle
Subscribers: MatzeB, arsenm, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60864
llvm-svn: 358740
1 file changed