diff --git a/libc/src/__support/FPUtil/CMakeLists.txt b/libc/src/__support/FPUtil/CMakeLists.txt
--- a/libc/src/__support/FPUtil/CMakeLists.txt
+++ b/libc/src/__support/FPUtil/CMakeLists.txt
@@ -13,12 +13,14 @@
     NormalFloat.h
     PlatformDefs.h
     builtin_wrappers.h
+    except_value_utils.h
   DEPENDS
     libc.include.math
     libc.include.errno
     libc.include.fenv
     libc.src.__support.common
     libc.src.__support.CPP.bit
+    libc.src.__support.CPP.optional
     libc.src.__support.CPP.type_traits
     libc.src.__support.CPP.uint128
     libc.src.errno.errno
diff --git a/libc/src/__support/FPUtil/except_value_utils.h b/libc/src/__support/FPUtil/except_value_utils.h
new file mode 100644
--- /dev/null
+++ b/libc/src/__support/FPUtil/except_value_utils.h
@@ -0,0 +1,112 @@
+//===-- Common header for helpers to set exceptional values -----*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SUPPORT_FPUTIL_EXCEPT_VALUE_UTILS_H
+#define LLVM_LIBC_SRC_SUPPORT_FPUTIL_EXCEPT_VALUE_UTILS_H
+
+#include "FEnvImpl.h"
+#include "FPBits.h"
+#include "src/__support/CPP/Optional.h"
+
+namespace __llvm_libc {
+
+namespace fputil {
+
+// This file contains utility functions and classes to manage exceptional values
+// when there are many of them.
+//
+// Example usage:
+//
+// Define list of exceptional inputs and outputs:
+//   static constexpr int N = ...;  // Number of exceptional values.
+//   static constexpr fputil::ExceptValues<float, N> Excepts {
+//     {  <list of input bits> },
+//     {  <list of output bits and offsets> }
+//   };
+//
+// Check for exceptional inputs:
+//   if (auto result = check_except_values<float, N>(Excepts, x_bits);
+//       unlikely(result.has_value()))
+//     return result.value();
+
+template <typename T> struct ExceptValueOutput {
+  T rnd_towardzero_result;
+  T rnd_upward_offset;
+  T rnd_downward_offset;
+  T rnd_tonearest_offset;
+};
+
+template <typename T, int N> struct ExceptValues {
+  using UIntType = typename FPBits<T>::UIntType;
+  static constexpr int SIZE = N;
+  // Input bits.
+  UIntType inputs[SIZE];
+  ExceptValueOutput<UIntType> outputs[SIZE];
+};
+
+template <typename T, int N>
+cpp::Optional<T> check_except_values(const ExceptValues<T, N> &ExceptVals,
+                                     typename FPBits<T>::UIntType x_bits) {
+  using UIntType = typename FPBits<T>::UIntType;
+  for (int i = 0; i < N; ++i) {
+    if (unlikely(x_bits == ExceptVals.inputs[i])) {
+      UIntType out_bits = ExceptVals.outputs[i].rnd_towardzero_result;
+      switch (fputil::get_round()) {
+      case FE_UPWARD:
+        out_bits += ExceptVals.outputs[i].rnd_upward_offset;
+        break;
+      case FE_DOWNWARD:
+        out_bits += ExceptVals.outputs[i].rnd_downward_offset;
+        break;
+      case FE_TONEAREST:
+        out_bits += ExceptVals.outputs[i].rnd_tonearest_offset;
+        break;
+      }
+      return FPBits<T>(out_bits).get_val();
+    }
+  }
+  return cpp::Nullopt;
+}
+
+// Check exceptional values for odd functions: f(-x) = -f(x).
+template <typename T, int N>
+cpp::Optional<T>
+check_odd_func_except_values(const ExceptValues<T, N> &ExceptVals,
+                             typename FPBits<T>::UIntType x_abs, bool sign) {
+  using UIntType = typename FPBits<T>::UIntType;
+  for (int i = 0; i < N; ++i) {
+    if (unlikely(x_abs == ExceptVals.inputs[i])) {
+      UIntType out_bits = ExceptVals.outputs[i].rnd_towardzero_result;
+      switch (fputil::get_round()) {
+      case FE_UPWARD:
+        out_bits += sign ? ExceptVals.outputs[i].rnd_downward_offset
+                         : ExceptVals.outputs[i].rnd_upward_offset;
+        break;
+      case FE_DOWNWARD:
+        out_bits += sign ? ExceptVals.outputs[i].rnd_upward_offset
+                         : ExceptVals.outputs[i].rnd_downward_offset;
+        break;
+      case FE_TONEAREST:
+        out_bits += ExceptVals.outputs[i].rnd_tonearest_offset;
+        break;
+      }
+      result = FPBits<T>(out_bits).get_val();
+      if (sign)
+        result = -result;
+
+      return result;
+    }
+  }
+  return cpp::Nullopt;
+}
+
+} // namespace fputil
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_SUPPORT_FPUTIL_EXCEPT_VALUE_UTILS_H
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -161,6 +161,7 @@
     "src/__support/FPUtil/NormalFloat.h",
     "src/__support/FPUtil/PlatformDefs.h",
     "src/__support/FPUtil/builtin_wrappers.h",
+    "src/__support/FPUtil/except_value_utils.h",
 ]
 
 fputil_hdrs = selects.with_or({