[PATCH] D46162: [PowerPC] Don't transform to CTR loop if the decrement branch instr. would end up in a different loop

[Eli Friedman via Phabricator via llvm-commits]

efriedma added inline comments.


================
Comment at: lib/Target/PowerPC/PPCCTRLoops.cpp:579
+    if (LI->getLoopFor(*I) != L)
+      continue;
+
----------------
The actual condition you need to check is whether the branch executes exactly once per iteration.

For most code, this check is equivalent, but it's possible to have an irreducible "loop" which is not an LLVM Loop.


Repository:
  rL LLVM

https://reviews.llvm.org/D46162