[PATCH] D32324: CodeGen: BlockPlacement: Increase tail duplication size for O3.

[Kyle Butt via Phabricator via llvm-commits]

iteratee added inline comments.


================
Comment at: lib/CodeGen/MachineBlockPlacement.cpp:2662
+  // conservative.
+  if (PassConfig->getOptLevel() >= CodeGenOpt::Aggressive) {
+    // At O3 we should be more willing to copy blocks for tail duplication. This
----------------
davidxl wrote:
> I think when the aggressive threshold is also explicitly specified, then it should take precedence even at O2. Basically this is the order:
> 
> Explicit Aggressive Threshold
> Explicit regular Threshold
> 
> Implicit Aggressive at O3 and implicit regular at O2.
At O3 I think it should be:

Explicit Aggressive Threshold
Explicit Regular Threshold
Implicit Aggressive Threshold

At O2 I think it should be:

Explicit Regular Threshold
Explicit Aggressive Threshold
Implicit Regular Threshold

For instance someone may want to adjust both flags globally and compile individual modules at O2 or O3.



https://reviews.llvm.org/D32324