[PATCH] D18898: [Loop Rotation] Make default max rotation header size threshold dependent on target CPU

[Eric Christopher via llvm-commits]

echristo added a comment.

This is in my list, I'm trying to fix a bit of the pass before this. It shouldn't be too bad though.


================
Comment at: lib/Target/X86/X86TargetTransformInfo.cpp:1591
@@ +1590,3 @@
+
+unsigned X86TTIImpl::getLoopRotationDefaultThreshold() const {
+  // The loop rotation threshold equal to 2 shows the best performance and code
----------------
Can you elaborate? What did you test on, do you know why? Is it just magic or is it based on something about the cpu?


https://reviews.llvm.org/D18898