[PATCH] D27742: CodeGen: Allow small copyable blocks to "break" the CFG.

[David Li via Phabricator via llvm-commits]

davidxl added a comment.

do you forget to include the new test in the patch, I still can not find it.



================
Comment at: lib/CodeGen/MachineBlockPlacement.cpp:568
+
+  if (!IsSimple && BB->succ_size() == 1)
+    return false;
----------------
iteratee wrote:
> davidxl wrote:
> > && --> || ?
> > 
> > In other words, do we care about block dup of simple blocks in layout mode?
> Simple blocks contain only an unconditional jump. I don't see a good reason to exclude them during layout.
Basically you are trying to tail duplicate such simple blocks in layout -- what is the benefit? It does not create more fall-through opportunities.


https://reviews.llvm.org/D27742