[Analysis] reduce code for isOnlyUsedInZeroEqualityComparison; NFC

There's a bug here noted by the FIXME and visible in variations of PR50836.

1 files changed, 6 insertions, 10 deletions

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index d381ee2..9458c89 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -279,16 +279,12 @@ bool llvm::haveNoCommonBitsSet(const Value *LHS, const Value *RHS,
   return KnownBits::haveNoCommonBitsSet(LHSKnown, RHSKnown);
 }
 
-bool llvm::isOnlyUsedInZeroEqualityComparison(const Instruction *CxtI) {
-  for (const User *U : CxtI->users()) {
-    if (const ICmpInst *IC = dyn_cast<ICmpInst>(U))
-      if (IC->isEquality())
-        if (Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
-          if (C->isNullValue())
-            continue;
-    return false;
-  }
-  return true;
+bool llvm::isOnlyUsedInZeroEqualityComparison(const Instruction *I) {
+  // FIXME: Should not return true if there are no users.
+  return all_of(I->users(), [](const User *U) {
+    ICmpInst::Predicate P;
+    return match(U, m_ICmp(P, m_Value(), m_Zero())) && ICmpInst::isEquality(P);
+  });
 }
 
 static bool isKnownToBeAPowerOfTwo(const Value *V, bool OrZero, unsigned Depth,