[llvm] [InstCombine] Fold `(icmp eq/ne (or (select cond, 0/NZ, 0/NZ), X), 0)` (PR #88183)

[Yingwei Zheng via llvm-commits]

================
@@ -3491,6 +3491,57 @@ Instruction *InstCombinerImpl::foldICmpBinOpEqualityWithConstant(
       Value *And = Builder.CreateAnd(BOp0, NotBOC);
       return new ICmpInst(Pred, And, NotBOC);
     }
+    // (icmp eq (or (select cond, 0, NonZero), Other), 0)
+    //  -> (and cond, (icmp eq Other, 0))
+    // (icmp ne (or (select cond, NonZero, 0), Other), 0)
+    //  -> (or cond, (icmp ne Other, 0))
+    Value *Cond, *TV, *FV, *Other;
+    if (C.isZero() &&
+        match(BO,
+              m_OneUse(m_c_Or(m_Select(m_Value(Cond), m_Value(TV), m_Value(FV)),
+                              m_Value(Other))))) {
+      const SimplifyQuery Q = SQ.getWithInstruction(&Cmp);
+      // Easy case is if eq/ne matches whether 0 is trueval/falseval.
+      if (Pred == ICmpInst::ICMP_EQ
+              ? (match(TV, m_SpecificInt(C)) && isKnownNonZero(FV, Q))
----------------
dtcxzyw wrote:

```suggestion
              ? (match(TV, m_Zero()) && isKnownNonZero(FV, Q))
```

https://github.com/llvm/llvm-project/pull/88183