[PATCH] D115747: [AMDGPU] Flush the vmcnt counter in loop preheader when necessary

[Jay Foad via Phabricator via llvm-commits]

foad added inline comments.


================
Comment at: llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp:1654
+
+  for (MachineLoop *const LI : *MLI) {
+    if (LI->getLoopPreheader() != &MBB)
----------------
I think the definition of a preheader is that it has a single successor, which is the header. So you should not have to search through all loops in the function here, just look up the loop for MBB's successor and then walk up its parents.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D115747/new/

https://reviews.llvm.org/D115747