[llvm] [VPlan] Simplify (X && Y) || (X && !Y) -> X. (PR #89386)

[via llvm-commits]

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@@ -192,6 +191,47 @@ using AllBinaryRecipe_match =
     BinaryRecipe_match<Op0_t, Op1_t, Opcode, VPWidenRecipe, VPReplicateRecipe,
                        VPWidenCastRecipe, VPInstruction>;
 
+template <typename Op0_t, typename Op1_t, unsigned Opcode, bool Commutable,
+          typename... RecipeTys>
+struct LogicalRecipe_match {
+  Op0_t LHS;
+  Op1_t RHS;
+
+  LogicalRecipe_match(Op0_t LHS, Op1_t RHS) : LHS(LHS), RHS(RHS) {}
+
+  bool match(const VPValue *V) {
+    auto *DefR = V->getDefiningRecipe();
+    return DefR && match(DefR);
+  }
+
+  bool match(const VPSingleDefRecipe *R) {
+    return match(static_cast<const VPRecipeBase *>(R));
+  }
+
+  bool match(const VPRecipeBase *R) {
+    if (!detail::MatchRecipeAndOpcode<Opcode, RecipeTys...>::match(R)) {
+      if (!detail::MatchRecipeAndOpcode<Instruction::Select,
+                                        RecipeTys...>::match(R))
+        return false;
+      if (Opcode == Instruction::And) {
+        if (!m_False().match(R->getOperand(2)))
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ayalz wrote:

This stems from searching for `select i1 %c, i1 %a, i1 0` as the poison-preserving form of `and i1 %c, %a`? Would it be clearer for VPlan to represent Poison-Preserving AND/OR directly, possibly via a flag, whose execute() emits the desired select patterns, rather than reverse-engineer them?

https://github.com/llvm/llvm-project/pull/89386