diff --git a/mlir/lib/Conversion/ComplexToLibm/ComplexToLibm.cpp b/mlir/lib/Conversion/ComplexToLibm/ComplexToLibm.cpp
--- a/mlir/lib/Conversion/ComplexToLibm/ComplexToLibm.cpp
+++ b/mlir/lib/Conversion/ComplexToLibm/ComplexToLibm.cpp
@@ -73,6 +73,10 @@
                                                     "csqrtf", "csqrt", benefit);
   patterns.add<ScalarOpToLibmCall<complex::TanhOp>>(patterns.getContext(),
                                                     "ctanhf", "ctanh", benefit);
+  patterns.add<ScalarOpToLibmCall<complex::CosOp>>(patterns.getContext(),
+                                                   "ccosf", "ccos", benefit);
+  patterns.add<ScalarOpToLibmCall<complex::SinOp>>(patterns.getContext(),
+                                                   "csinf", "csin", benefit);
 }
 
 namespace {
diff --git a/mlir/test/Conversion/ComplexToLibm/convert-to-libm.mlir b/mlir/test/Conversion/ComplexToLibm/convert-to-libm.mlir
--- a/mlir/test/Conversion/ComplexToLibm/convert-to-libm.mlir
+++ b/mlir/test/Conversion/ComplexToLibm/convert-to-libm.mlir
@@ -6,6 +6,8 @@
 // CHECK-DAG: @csqrt(complex<f64>) -> complex<f64>
 // CHECK-DAG: @ctanhf(complex<f32>) -> complex<f32>
 // CHECK-DAG: @ctanh(complex<f64>) -> complex<f64>
+// CHECK-DAG: @ccos(complex<f64>) -> complex<f64>
+// CHECK-DAG: @csin(complex<f64>) -> complex<f64>
 
 // CHECK-LABEL: func @cpow_caller
 // CHECK-SAME: %[[FLOAT:.*]]: complex<f32>
@@ -42,3 +44,27 @@
   // CHECK: return %[[FLOAT_RESULT]], %[[DOUBLE_RESULT]]
   return %float_result, %double_result : complex<f32>, complex<f64>
 }
+
+// CHECK-LABEL: func @ccos_caller
+// CHECK-SAME: %[[FLOAT:.*]]: complex<f32>
+// CHECK-SAME: %[[DOUBLE:.*]]: complex<f64>
+func.func @ccos_caller(%float: complex<f32>, %double: complex<f64>) -> (complex<f32>, complex<f64>)  {
+  // CHECK-DAG: %[[FLOAT_RESULT:.*]] = call @ccosf(%[[FLOAT]]) : (complex<f32>) -> complex<f32>
+  %float_result = complex.cos %float : complex<f32>
+  // CHECK-DAG: %[[DOUBLE_RESULT:.*]] = call @ccos(%[[DOUBLE]]) : (complex<f64>) -> complex<f64>
+  %double_result = complex.cos %double : complex<f64>
+  // CHECK: return %[[FLOAT_RESULT]], %[[DOUBLE_RESULT]]
+  return %float_result, %double_result : complex<f32>, complex<f64>
+}
+
+// CHECK-LABEL: func @csin_caller
+// CHECK-SAME: %[[FLOAT:.*]]: complex<f32>
+// CHECK-SAME: %[[DOUBLE:.*]]: complex<f64>
+func.func @csin_caller(%float: complex<f32>, %double: complex<f64>) -> (complex<f32>, complex<f64>)  {
+  // CHECK-DAG: %[[FLOAT_RESULT:.*]] = call @csinf(%[[FLOAT]]) : (complex<f32>) -> complex<f32>
+  %float_result = complex.sin %float : complex<f32>
+  // CHECK-DAG: %[[DOUBLE_RESULT:.*]] = call @csin(%[[DOUBLE]]) : (complex<f64>) -> complex<f64>
+  %double_result = complex.sin %double : complex<f64>
+  // CHECK: return %[[FLOAT_RESULT]], %[[DOUBLE_RESULT]]
+  return %float_result, %double_result : complex<f32>, complex<f64>
+}
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