[PATCH] D100002: [CSSPGO] Move pseudo probes to the beginning of a block to unblock SelectionDAG combine.

[Hongtao Yu via Phabricator via llvm-commits]

hoy added inline comments.


================
Comment at: llvm/lib/CodeGen/CodeGenPrepare.cpp:8001
+    // Remove redundant pseudo probes.
+    MadeChange |= removeRedundantPseudoProbes(&Block);
+    // Move the rest probes to the beginning of the block.
----------------
wenlei wrote:
> For dbg values, redundancy removal and placement are separate. Do we want to follow that? 
> 
> Since removeRedundantPseudoProbes is part of RemoveRedundantDbgInstrs already, how critical is this extra removal? 
Good point. They should be separate for pseudo probes as well, to be consistent with debug instrs.

The removal is not critical. It doesn't block DAG optimizations. Though it would be nice to remove redundancy from time to time for compilation time. This can be done as a separate change to find more promising places for redundancy removal. Removing it for now.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D100002/new/

https://reviews.llvm.org/D100002