[llvm] [VectorCombine] Fold vector.reduce.OP(F(X)) == 0 -> OP(X) == 0 (PR #173069)

[Yingwei Zheng via llvm-commits]

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@@ -3806,6 +3807,192 @@ bool VectorCombine::foldCastFromReductions(Instruction &I) {
   return true;
 }
 
+/// Match a non-zero and non-poison integer or a vector with all non-zero and
+/// non-poison elements.
+static cst_pred_ty<is_non_zero_int, /*AllowPoison=*/false>
+m_NonZeroNonPoisonInt() {
+  return cst_pred_ty<is_non_zero_int, /*AllowPoison=*/false>();
+}
+
+bool VectorCombine::foldICmpEqZeroVectorReduce(Instruction &I) {
+  // vector.reduce.OP f(X_i) == 0 -> vector.reduce.OP X_i == 0
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dtcxzyw wrote:

Move these comments above the function.

https://github.com/llvm/llvm-project/pull/173069