diff --git a/libc/src/stdlib/lldiv.cpp b/libc/src/stdlib/lldiv.cpp
@@ -0,0 +1,21 @@
+//===-- Implementation of lldiv -------------------------------------------===//
+//
+// 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 "src/stdlib/lldiv.h"
+#include "src/__support/common.h"
+#include "src/__support/integer_operations.h"
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(lldiv_t, lldiv, (long long x, long long y)) {
+  lldiv_t res;
+  integerRemQuo(x, y, res.quot, res.rem);
+  return res;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/stdlib/lldiv.h b/libc/src/stdlib/lldiv.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for lldiv -------------------------*- 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 <stdlib.h>
+
+#ifndef LLVM_LIBC_SRC_STDLIB_LLDIV_H
+#define LLVM_LIBC_SRC_STDLIB_LLDIV_H
+
+namespace __llvm_libc {
+
+lldiv_t lldiv(long long x, long long y);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_STDLIB_LDIV_H
diff --git a/libc/test/src/inttypes/CMakeLists.txt b/libc/test/src/inttypes/CMakeLists.txt
@@ -19,3 +19,16 @@ add_libc_unittest(
   DEPENDS
     libc.src.inttypes.strtoumax
 )
+
+add_libc_unittest(
+  imaxdiv_test
+  SUITE
+    libc_inttypes_unittests
+  SRCS
+    imaxdiv_test.cpp
+  HDRS
+    ../stdlib/DivTest.h
+  DEPENDS
+    libc.include.stdlib
+    libc.src.inttypes.imaxdiv
+)
diff --git a/libc/test/src/inttypes/imaxdiv_test.cpp b/libc/test/src/inttypes/imaxdiv_test.cpp
@@ -0,0 +1,15 @@
+//===-- Unittests for imaxdiv ---------------------------------------------===//
+//
+// 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 "../stdlib/DivTest.h"
+
+#include "src/inttypes/imaxdiv.h"
+
+#include <inttypes.h>
+
+LIST_DIV_TESTS(intmax_t, imaxdiv_t, __llvm_libc::imaxdiv)
diff --git a/libc/test/src/stdlib/CMakeLists.txt b/libc/test/src/stdlib/CMakeLists.txt
@@ -128,3 +128,42 @@ add_libc_unittest(
   DEPENDS
     libc.src.stdlib.llabs
 )
+
+add_libc_unittest(
+  div_test
+  SUITE
+    libc_stdlib_unittests
+  SRCS
+    div_test.cpp
+  HDRS
+    DivTest.h
+  DEPENDS
+    libc.include.stdlib
+    libc.src.stdlib.div
+)
+
+add_libc_unittest(
+  ldiv_test
+  SUITE
+    libc_stdlib_unittests
+  SRCS
+    ldiv_test.cpp
+  HDRS
+    DivTest.h
+  DEPENDS
+    libc.include.stdlib
+    libc.src.stdlib.ldiv
+)
+
+add_libc_unittest(
+  lldiv_test
+  SUITE
+    libc_stdlib_unittests
+  SRCS
+    lldiv_test.cpp
+  HDRS
+    DivTest.h
+  DEPENDS
+    libc.include.stdlib
+    libc.src.stdlib.lldiv
+)
diff --git a/libc/test/src/stdlib/DivTest.h b/libc/test/src/stdlib/DivTest.h
@@ -0,0 +1,37 @@
+//===-- A template class for testing div functions --------------*- 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 "utils/UnitTest/Test.h"
+
+template <typename IntType, typename ReturnType>
+class DivTest : public __llvm_libc::testing::Test {
+public:
+  using DivFunc = ReturnType(IntType, IntType);
+
+  void simpleTest(DivFunc func) {
+    auto result = func(10, 3);
+    EXPECT_EQ(result.quot, IntType(3));
+    EXPECT_EQ(result.rem, IntType(1));
+
+    result = func(-10, 3);
+    EXPECT_EQ(result.quot, IntType(-3));
+    EXPECT_EQ(result.rem, IntType(-1));
+
+    result = func(-10, -3);
+    EXPECT_EQ(result.quot, IntType(3));
+    EXPECT_EQ(result.rem, IntType(-1));
+
+    result = func(10, -3);
+    EXPECT_EQ(result.quot, IntType(-3));
+    EXPECT_EQ(result.rem, IntType(1));
+  }
+};
+
+#define LIST_DIV_TESTS(IntType, ReturnType, func)                              \
+  using LlvmLibcDivTest = DivTest<IntType, ReturnType>;                        \
+  TEST_F(LlvmLibcDivTest, SimpleTest) { simpleTest(func); }
diff --git a/libc/test/src/stdlib/div_test.cpp b/libc/test/src/stdlib/div_test.cpp
@@ -0,0 +1,15 @@
+//===-- Unittests for div -------------------------------------------------===//
+//
+// 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 "DivTest.h"
+
+#include "src/stdlib/div.h"
+
+#include <stdlib.h>
+
+LIST_DIV_TESTS(int, div_t, __llvm_libc::div)
diff --git a/libc/test/src/stdlib/ldiv_test.cpp b/libc/test/src/stdlib/ldiv_test.cpp
@@ -0,0 +1,15 @@
+//===-- Unittests for ldiv ------------------------------------------------===//
+//
+// 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 "DivTest.h"
+
+#include "src/stdlib/ldiv.h"
+
+#include <stdlib.h>
+
+LIST_DIV_TESTS(long, ldiv_t, __llvm_libc::ldiv)
diff --git a/libc/test/src/stdlib/lldiv_test.cpp b/libc/test/src/stdlib/lldiv_test.cpp
@@ -0,0 +1,15 @@
+//===-- Unittests for lldiv -----------------------------------------------===//
+//
+// 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 "DivTest.h"
+
+#include "src/stdlib/lldiv.h"
+
+#include <stdlib.h>
+
+LIST_DIV_TESTS(long long, lldiv_t, __llvm_libc::lldiv)