[PATCH] D111846: [LV] Drop integer poison-generating flags from instructions that need predication

[Nuno Lopes via Phabricator via llvm-commits]

nlopes added a comment.

Looks good to me. Added a couple of suggestions to the code.



================
Comment at: llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:3034
+  // VPWidenMemoryInstructionRecipe or VPInterleaveRecipe.
+  while (!Worklist.empty()) {
+    VPValue *CurDef = Worklist.back();
----------------
isn't it inefficient to recompute this information for every operation? You get a O(n^2) behavior (up to n calls of this function, each traversing up to n instructions) 


================
Comment at: llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:3041
+
+    // Address computation should only happen on integer types.
+    // TODO: Retrieve the type from the VPRecipes/VPInstructions when available.
----------------
An address computation may depend on float operations. e.g. you may have a float -> int, a select based on a float comparison, etc.


================
Comment at: llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:3056
+          return true;
+
+        for (auto *SingleDef : RecBase->definedValues())
----------------
you don't need to consider users of loads (nor of stores). you can break here if you want if WidenMemRec != nullptr.


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https://reviews.llvm.org/D111846