4 files changed, 26 insertions, 0 deletions
diff --git a/libc/utils/MPFRWrapper/MPCommon.cpp b/libc/utils/MPFRWrapper/MPCommon.cpp
index 77039d4bf7df..c25522077411 100644
--- a/libc/utils/MPFRWrapper/MPCommon.cpp
+++ b/libc/utils/MPFRWrapper/MPCommon.cpp
@@ -138,6 +138,21 @@ MPFRNumber MPFRNumber::atanh() const {
   return result;
 }
 
+MPFRNumber MPFRNumber::atanpi() const {
+  MPFRNumber result(*this);
+#if MPFR_VERSION >= MPFR_VERSION_NUM(4, 2, 0)
+  mpfr_atanpi(result.value, value, mpfr_rounding);
+  return result;
+#else
+  MPFRNumber value_atan(0.0, mpfr_precision * 3);
+  mpfr_atan(value_atan.value, value, MPFR_RNDN);
+  MPFRNumber value_pi(0.0, mpfr_precision * 3);
+  mpfr_const_pi(value_pi.value, MPFR_RNDN);
+  mpfr_div(result.value, value_atan.value, value_pi.value, mpfr_rounding);
+  return result;
+#endif
+}
+
 MPFRNumber MPFRNumber::cbrt() const {
   MPFRNumber result(*this);
   mpfr_cbrt(result.value, value, mpfr_rounding);
diff --git a/libc/utils/MPFRWrapper/MPCommon.h b/libc/utils/MPFRWrapper/MPCommon.h
index 47d6293c06af..25bdc9bc0025 100644
--- a/libc/utils/MPFRWrapper/MPCommon.h
+++ b/libc/utils/MPFRWrapper/MPCommon.h
@@ -193,6 +193,7 @@ public:
   MPFRNumber atan() const;
   MPFRNumber atan2(const MPFRNumber &b);
   MPFRNumber atanh() const;
+  MPFRNumber atanpi() const;
   MPFRNumber cbrt() const;
   MPFRNumber ceil() const;
   MPFRNumber cos() const;
diff --git a/libc/utils/MPFRWrapper/MPFRUtils.cpp b/libc/utils/MPFRWrapper/MPFRUtils.cpp
index 2155f324aa8a..144a4ec25d21 100644
--- a/libc/utils/MPFRWrapper/MPFRUtils.cpp
+++ b/libc/utils/MPFRWrapper/MPFRUtils.cpp
@@ -45,6 +45,8 @@ unary_operation(Operation op, InputType input, unsigned int precision,
     return mpfrInput.atan();
   case Operation::Atanh:
     return mpfrInput.atanh();
+  case Operation::Atanpi:
+    return mpfrInput.atanpi();
   case Operation::Cbrt:
     return mpfrInput.cbrt();
   case Operation::Ceil:
@@ -272,6 +274,10 @@ template void explain_unary_operation_single_output_error(Operation op,
                                                           double, RoundingMode);
 #endif // LIBC_TYPES_FLOAT128_IS_NOT_LONG_DOUBLE
 
+template void explain_unary_operation_single_output_error(Operation op,
+                                                          bfloat16, bfloat16,
+                                                          double, RoundingMode);
+
 template <typename T>
 void explain_unary_operation_two_outputs_error(
     Operation op, T input, const BinaryOutput<T> &libc_result,
@@ -559,6 +565,9 @@ template bool compare_unary_operation_single_output(Operation, float128,
                                                     long double, double,
                                                     RoundingMode);
 #endif // LIBC_TYPES_FLOAT128_IS_NOT_LONG_DOUBLE
+template bool compare_unary_operation_single_output(Operation, bfloat16,
+                                                    bfloat16, double,
+                                                    RoundingMode);
 
 template <typename T>
 bool compare_unary_operation_two_outputs(Operation op, T input,
diff --git a/libc/utils/MPFRWrapper/MPFRUtils.h b/libc/utils/MPFRWrapper/MPFRUtils.h
index e805607328f6..35d7942a2620 100644
--- a/libc/utils/MPFRWrapper/MPFRUtils.h
+++ b/libc/utils/MPFRWrapper/MPFRUtils.h
@@ -33,6 +33,7 @@ enum class Operation : int {
   Asinpi,
   Atan,
   Atanh,
+  Atanpi,
   Cbrt,
   Ceil,
   Cos,