diff --git a/libc/test/src/CMakeLists.txt b/libc/test/src/CMakeLists.txt
@@ -44,6 +44,7 @@ add_subdirectory(inttypes)
 add_subdirectory(math)
 add_subdirectory(search)
 add_subdirectory(stdbit)
+add_subdirectory(stdfix)
 add_subdirectory(stdio)
 add_subdirectory(stdlib)
 add_subdirectory(string)

diff --git a/libc/test/src/stdfix/AbsTest.h b/libc/test/src/stdfix/AbsTest.h
@@ -0,0 +1,37 @@
+//===-- Utility class to test fixed-point abs -------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "test/UnitTest/Test.h"
+
+#include "src/__support/fixed_point/fx_rep.h"
+
+template <typename T> class AbsTest : public LIBC_NAMESPACE::testing::Test {
+
+  using FXRep = LIBC_NAMESPACE::fixed_point::FXRep<T>;
+  static constexpr T zero = FXRep::ZERO();
+  static constexpr T min = FXRep::MIN();
+  static constexpr T max = FXRep::MAX();
+  static constexpr T half = static_cast<T>(0.5);
+  static constexpr T neg_half = static_cast<T>(-0.5);
+
+public:
+  typedef T (*AbsFunc)(T);
+
+  void testSpecialNumbers(AbsFunc func) {
+    EXPECT_EQ(zero, func(zero));
+    EXPECT_EQ(max, func(min));
+    EXPECT_EQ(max, func(max));
+    EXPECT_EQ(half, func(half));
+    EXPECT_EQ(half, func(neg_half));
+  }
+};
+
+#define LIST_ABS_TESTS(T, func)                                                \
+  using LlvmLibcAbsTest = AbsTest<T>;                                          \
+  TEST_F(LlvmLibcAbsTest, SpecialNumbers) { testSpecialNumbers(&func); }       \
+  static_assert(true, "Require semicolon.")
diff --git a/libc/test/src/stdfix/CMakeLists.txt b/libc/test/src/stdfix/CMakeLists.txt
@@ -0,0 +1,23 @@
+if(NOT LIBC_COMPILER_HAS_FIXED_POINT)
+  return()
+endif()
+
+add_custom_target(libc-stdfix-tests)
+
+foreach(suffix IN ITEMS hr r lr hk k lk)
+  add_libc_test(
+    abs${suffix}_test
+    SUITE
+      libc-stdfix-tests
+    HDRS
+      AbsTest.h
+    SRCS
+      abs${suffix}_test.cpp
+    COMPILE_OPTIONS
+      -O3
+      -ffixed-point
+    DEPENDS
+      libc.src.stdfix.abs${suffix}
+      libc.src.__support.fixed_point.fx_bits
+  )
+endforeach()
diff --git a/libc/test/src/stdfix/abshk_test.cpp b/libc/test/src/stdfix/abshk_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for abshk -----------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "AbsTest.h"
+
+#include "src/stdfix/abshk.h"
+
+LIST_ABS_TESTS(short accum, LIBC_NAMESPACE::abshk);
diff --git a/libc/test/src/stdfix/abshr_test.cpp b/libc/test/src/stdfix/abshr_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for abshr -----------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "AbsTest.h"
+
+#include "src/stdfix/abshr.h"
+
+LIST_ABS_TESTS(short fract, LIBC_NAMESPACE::abshr);
diff --git a/libc/test/src/stdfix/absk_test.cpp b/libc/test/src/stdfix/absk_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for absk ------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "AbsTest.h"
+
+#include "src/stdfix/absk.h"
+
+LIST_ABS_TESTS(accum, LIBC_NAMESPACE::absk);
diff --git a/libc/test/src/stdfix/abslk_test.cpp b/libc/test/src/stdfix/abslk_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for abslk -----------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "AbsTest.h"
+
+#include "src/stdfix/abslk.h"
+
+LIST_ABS_TESTS(long accum, LIBC_NAMESPACE::abslk);
diff --git a/libc/test/src/stdfix/abslr_test.cpp b/libc/test/src/stdfix/abslr_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for abslr -----------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "AbsTest.h"
+
+#include "src/stdfix/abslr.h"
+
+LIST_ABS_TESTS(long fract, LIBC_NAMESPACE::abslr);
diff --git a/libc/test/src/stdfix/absr_test.cpp b/libc/test/src/stdfix/absr_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for absr ------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "AbsTest.h"
+
+#include "src/stdfix/absr.h"
+
+LIST_ABS_TESTS(fract, LIBC_NAMESPACE::absr);