1 files changed, 5 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index 20a2ae1..e961139 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -1228,6 +1228,11 @@ static bool combineToUSubWithOverflow(CmpInst *Cmp, const TargetLowering &TLI,
     B = ConstantInt::get(B->getType(), 1);
     Pred = ICmpInst::ICMP_ULT;
   }
+  // Convert special-case: (A != 0) is the same as (0 u< A).
+  if (Pred == ICmpInst::ICMP_NE && match(B, m_ZeroInt())) {
+    std::swap(A, B);
+    Pred = ICmpInst::ICMP_ULT;
+  }
   if (Pred != ICmpInst::ICMP_ULT)
     return false;