[PATCH] D11662: Filter cold blocks off the loop chain when profile data is available.

[David]

davidxl added a comment.

Ok -- the change is made to be consistent with existing trace formation heuristic to improve locality. It outlines the cold blocks and allow them to be pushed away further so that trace can be formed from the current loop with loop exit blocks..


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Comment at: lib/CodeGen/MachineBlockPlacement.cpp:826
@@ +825,3 @@
+    // We use the threshold 20% here to filter cold blocks.
+    const unsigned LoopToColdBBRatio = 5;
+    for (MachineBasicBlock *LoopBB : L.getBlocks()) {
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Try to avoid hard-coding parameter like this.


http://reviews.llvm.org/D11662