diff --git a/src/target/llvm/intrin_rule_llvm.cc b/src/target/llvm/intrin_rule_llvm.cc
index 3244deab875b..3c7f9c6d799e 100644
--- a/src/target/llvm/intrin_rule_llvm.cc
+++ b/src/target/llvm/intrin_rule_llvm.cc
@@ -143,32 +143,16 @@ TVM_REGISTER_OP("tirx.tan")
 
 TVM_REGISTER_OP("tirx.cosh")
     .set_attr<FLegalize>("llvm.FLegalize", [](const PrimExpr& e) -> PrimExpr {
-      using tirx::make_const;
-      using tirx::make_zero;
       const tirx::CallNode* call = e.as<tirx::CallNode>();
       TVM_FFI_ICHECK(call != nullptr);
-      const PrimExpr& x = call->args[0];
-      PrimExpr two = make_const(x.dtype(), 2);
-      PrimExpr neg_one = make_const(x.dtype(), -1);
-      PrimExpr exp_negx = exp(neg_one * x);
-      PrimExpr exp_posx = exp(x);
-      PrimExpr ret = (exp_posx + exp_negx) / two;
-      return ret;
+      return ::tvm::codegen::intrin::DispatchPureExtern<::tvm::codegen::intrin::FloatSuffix>(e);
     });
 
 TVM_REGISTER_OP("tirx.sinh")
     .set_attr<FLegalize>("llvm.FLegalize", [](const PrimExpr& e) -> PrimExpr {
-      using tirx::make_const;
-      using tirx::make_zero;
       const tirx::CallNode* call = e.as<tirx::CallNode>();
       TVM_FFI_ICHECK(call != nullptr);
-      const PrimExpr& x = call->args[0];
-      PrimExpr two = make_const(x.dtype(), 2);
-      PrimExpr neg_one = make_const(x.dtype(), -1);
-      PrimExpr exp_negx = exp(neg_one * x);
-      PrimExpr exp_posx = exp(x);
-      PrimExpr ret = (exp_posx - exp_negx) / two;
-      return ret;
+      return ::tvm::codegen::intrin::DispatchPureExtern<::tvm::codegen::intrin::FloatSuffix>(e);
     });
 
 TVM_REGISTER_OP("tirx.asin")
@@ -232,35 +216,23 @@ TVM_REGISTER_OP("tirx.acos")
 
 TVM_REGISTER_OP("tirx.atan")
     .set_attr<FLegalize>("llvm.FLegalize", [](const PrimExpr& e) -> PrimExpr {
-      using tirx::make_const;
       const tirx::CallNode* call = e.as<tirx::CallNode>();
       TVM_FFI_ICHECK(call != nullptr) << "Invalid call node in atan legalization";
-      const PrimExpr& x = call->args[0];
-      PrimExpr one = make_const(x.dtype(), 1.0);
-      PrimExpr denom = sqrt(x * x + one);
-      return asin(x / denom);
+      return ::tvm::codegen::intrin::DispatchPureExtern<::tvm::codegen::intrin::FloatSuffix>(e);
     });
 
 TVM_REGISTER_OP("tirx.asinh")
     .set_attr<FLegalize>("llvm.FLegalize", [](const PrimExpr& e) -> PrimExpr {
-      using tirx::make_const;
       const tirx::CallNode* call = e.as<tirx::CallNode>();
       TVM_FFI_ICHECK(call != nullptr) << "Invalid call node in asinh legalization";
-      const PrimExpr& x = call->args[0];
-      PrimExpr one = make_const(x.dtype(), 1.0);
-      PrimExpr sqrt_val = sqrt(x * x + one);
-      return log(x + sqrt_val);
+      return ::tvm::codegen::intrin::DispatchPureExtern<::tvm::codegen::intrin::FloatSuffix>(e);
     });
 
 TVM_REGISTER_OP("tirx.acosh")
     .set_attr<FLegalize>("llvm.FLegalize", [](const PrimExpr& e) -> PrimExpr {
-      using tirx::make_const;
       const tirx::CallNode* call = e.as<tirx::CallNode>();
       TVM_FFI_ICHECK(call != nullptr) << "Invalid call node in acosh legalization";
-      const PrimExpr& x = call->args[0];
-      PrimExpr one = make_const(x.dtype(), 1.0);
-      PrimExpr sqrt_val = sqrt(x * x - one);
-      return log(x + sqrt_val);
+      return ::tvm::codegen::intrin::DispatchPureExtern<::tvm::codegen::intrin::FloatSuffix>(e);
     });
 
 TVM_REGISTER_OP("tirx.atanh")
@@ -275,21 +247,9 @@ TVM_REGISTER_OP("tirx.atanh")
 
 TVM_REGISTER_OP("tirx.erf")
     .set_attr<FLegalize>("llvm.FLegalize", [](const PrimExpr& e) -> PrimExpr {
-      using tirx::make_const;
       const tirx::CallNode* call = e.as<tirx::CallNode>();
       TVM_FFI_ICHECK(call != nullptr) << "Invalid call node in erf legalization";
-      const PrimExpr& x = call->args[0];
-      PrimExpr abs_x = tvm::abs(x);
-      PrimExpr t = make_const(x.dtype(), 1.0) /
-                   (make_const(x.dtype(), 1.0) + make_const(x.dtype(), 0.3275911) * abs_x);
-      PrimExpr a1 = make_const(x.dtype(), 0.254829592);
-      PrimExpr a2 = make_const(x.dtype(), -0.284496736);
-      PrimExpr a3 = make_const(x.dtype(), 1.421413741);
-      PrimExpr a4 = make_const(x.dtype(), -1.453152027);
-      PrimExpr a5 = make_const(x.dtype(), 1.061405429);
-      PrimExpr poly = (((((a5 * t + a4) * t + a3) * t + a2) * t + a1) * t);
-      PrimExpr approx = make_const(x.dtype(), 1.0) - poly * exp(-abs_x * abs_x);
-      return tvm::tirx::Select(x < 0, -approx, approx);
+      return ::tvm::codegen::intrin::DispatchPureExtern<::tvm::codegen::intrin::FloatSuffix>(e);
     });
 
 TVM_REGISTER_OP("tirx.clz")
diff --git a/tests/python/relax/test_frontend_onnx.py b/tests/python/relax/test_frontend_onnx.py
index 151ec35e897f..53e93b0b4d5a 100644
--- a/tests/python/relax/test_frontend_onnx.py
+++ b/tests/python/relax/test_frontend_onnx.py
@@ -707,7 +707,7 @@ def test_bitwise_shift(direction: str):
         "Tanh",
         # "Asin",  // TODO @jikechao, fix the precision loss due to the Taylor approximation
         # "Acos",
-        # "Atan",
+        "Atan",
         "Asinh",
         "Acosh",
         "Atanh",