[PATCH] D94996: [GVN] do not repeat PRE on failure to split critical edge

[Florian Hahn via Phabricator via llvm-commits]

fhahn added inline comments.


================
Comment at: llvm/lib/Transforms/Scalar/GVN.cpp:2695
     std::pair<Instruction *, unsigned> Edge = toSplit.pop_back_val();
-    SplitCriticalEdge(Edge.first, Edge.second,
-                      CriticalEdgeSplittingOptions(DT, LI, MSSAU));
+    Changed |= !!SplitCriticalEdge(Edge.first, Edge.second,
+                                   CriticalEdgeSplittingOptions(DT, LI, MSSAU));
----------------
do we need `!!` here?


================
Comment at: llvm/lib/Transforms/Scalar/GVN.cpp:2699
+  if (Changed) {
+    if (MD)
+      MD->invalidateCachedPredecessors();
----------------
This code seems redundant, right, because it is already done by `splitCriticalEdges`?


================
Comment at: llvm/test/Transforms/GVN/critical-edge-split-failure.ll:13
+
+define dso_local i32 @arch_static_branch() {
+entry:
----------------
is this function needed?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D94996/new/

https://reviews.llvm.org/D94996