[libc] Add implementations of ceil[f], floor[f] and trunc[f] from math.h.

[sivachandra]

If adding latex docs which explain the theoretical concepts behind the operations would be useful in general for math functions, I can work on that parallely/separately.

[sivachandra]

Use compiler generated instructions for floating point addition.

[sivachandra]

Use floating point literals for 1.0 and 0.0 instead of bit patterns.

[abrachet]

LGTM

libc/utils/FPUtil/FloatOperations.h

47

Maybe &=

libc/lib/CMakeLists.txt

DEPENDS
     # unistd.h entrypoints
     libc.src.unistd.write
 )
 
 add_entrypoint_library(
   llvmlibm
   DEPENDS
     # math.h entrypoints
+    libc.src.math.ceil
+    libc.src.math.ceilf
     libc.src.math.cosf
     libc.src.math.fabs
     libc.src.math.fabsf
+    libc.src.math.floor
+    libc.src.math.floorf
     libc.src.math.expf
     libc.src.math.exp2f
     libc.src.math.round
     libc.src.math.sincosf
     libc.src.math.sinf
+    libc.src.math.trunc
+    libc.src.math.truncf
 )
 
 add_redirector_library(
   llvmlibc_redirectors
   DEPENDS
     round_redirector
 )

libc/src/math/CMakeLists.txt

add_entrypoint_object(
   SRCS
     fabsf.cpp
   HDRS
     fabsf.h
   DEPENDS
     libc.utils.FPUtil.fputil
 )
 
+add_entrypoint_object(
+  trunc
+  SRCS
+    trunc.cpp
+  HDRS
+    trunc.h
+  DEPENDS
+    libc.utils.FPUtil.fputil
+)
+
+add_entrypoint_object(
+  truncf
+  SRCS
+    truncf.cpp
+  HDRS
+    truncf.h
+  DEPENDS
+    libc.utils.FPUtil.fputil
+)
+
+add_entrypoint_object(
+  ceil
+  SRCS
+    ceil.cpp
+  HDRS
+    ceil.h
+  DEPENDS
+    libc.utils.FPUtil.fputil
+)
+
+add_entrypoint_object(
+  ceilf
+  SRCS
+    ceilf.cpp
+  HDRS
+    ceilf.h
+  DEPENDS
+    libc.utils.FPUtil.fputil
+)
+
+add_entrypoint_object(
+  floor
+  SRCS
+    floor.cpp
+  HDRS
+    floor.h
+  DEPENDS
+    libc.utils.FPUtil.fputil
+)
+
+add_entrypoint_object(
+  floorf
+  SRCS
+    floorf.cpp
+  HDRS
+    floorf.h
+  DEPENDS
+    libc.utils.FPUtil.fputil
+)
+
 add_object_library(
   exp_utils
   HDRS
     exp_utils.h
   SRCS
     exp_utils.cpp
   DEPENDS
     .math_utils

libc/src/math/ceil.h

+//===-- Implementation header for ceil --------------------------*- 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_MATH_CEIL_H
+#define LLVM_LIBC_SRC_MATH_CEIL_H
+
+namespace __llvm_libc {
+
+double ceil(double x);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_MATH_CEIL_H

libc/src/math/ceil.cpp

+//===-- Implementation of ceil function -----------------------------------===//
+//
+// 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/__support/common.h"
+#include "utils/FPUtil/FloatOperations.h"
+
+namespace __llvm_libc {
+
+double LLVM_LIBC_ENTRYPOINT(ceil)(double x) { return fputil::ceil(x); }
+
+} // namespace __llvm_libc

libc/src/math/ceilf.h

+//===-- Implementation header for ceilf -------------------------*- 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_MATH_CEILF_H
+#define LLVM_LIBC_SRC_MATH_CEILF_H
+
+namespace __llvm_libc {
+
+float ceilf(float x);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_MATH_CEILF_H

libc/src/math/ceilf.cpp

+//===-- Implementation of ceilf function ----------------------------------===//
+//
+// 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/__support/common.h"
+#include "utils/FPUtil/FloatOperations.h"
+
+namespace __llvm_libc {
+
+float LLVM_LIBC_ENTRYPOINT(ceilf)(float x) { return fputil::ceil(x); }
+
+} // namespace __llvm_libc

libc/src/math/floor.h

+//===-- Implementation header for floor -------------------------*- 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_MATH_FLOOR_H
+#define LLVM_LIBC_SRC_MATH_FLOOR_H
+
+namespace __llvm_libc {
+
+double floor(double x);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_MATH_FLOOR_H

libc/src/math/floor.cpp

+//===-- Implementation of floor function ----------------------------------===//
+//
+// 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/__support/common.h"
+#include "utils/FPUtil/FloatOperations.h"
+
+namespace __llvm_libc {
+
+double LLVM_LIBC_ENTRYPOINT(floor)(double x) { return fputil::floor(x); }
+
+} // namespace __llvm_libc

libc/src/math/floorf.h

+//===-- Implementation header for floorf ------------------------*- 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_MATH_FLOORF_H
+#define LLVM_LIBC_SRC_MATH_FLOORF_H
+
+namespace __llvm_libc {
+
+float floorf(float x);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_MATH_FLOORF_H

libc/src/math/floorf.cpp

+//===-- Implementation of floorf function ---------------------------------===//
+//
+// 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/__support/common.h"
+#include "utils/FPUtil/FloatOperations.h"
+
+namespace __llvm_libc {
+
+float LLVM_LIBC_ENTRYPOINT(floorf)(float x) { return fputil::floor(x); }
+
+} // namespace __llvm_libc

libc/src/math/trunc.h

+//===-- Implementation header for trunc -------------------------*- 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_MATH_TRUNC_H
+#define LLVM_LIBC_SRC_MATH_TRUNC_H
+
+namespace __llvm_libc {
+
+double trunc(double x);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_MATH_TRUNC_H

libc/src/math/trunc.cpp

+//===-- Implementation of trunc function ----------------------------------===//
+//
+// 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/__support/common.h"
+#include "utils/FPUtil/FloatOperations.h"
+
+namespace __llvm_libc {
+
+double LLVM_LIBC_ENTRYPOINT(trunc)(double x) { return fputil::trunc(x); }
+
+} // namespace __llvm_libc

libc/src/math/truncf.h

+//===-- Implementation header for truncf ------------------------*- 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_MATH_TRUNCF_H
+#define LLVM_LIBC_SRC_MATH_TRUNCF_H
+
+namespace __llvm_libc {
+
+float truncf(float x);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_MATH_TRUNCF_H

libc/src/math/truncf.cpp

+//===-- Implementation of truncf function ---------------------------------===//
+//
+// 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/__support/common.h"
+#include "utils/FPUtil/FloatOperations.h"
+
+namespace __llvm_libc {
+
+float LLVM_LIBC_ENTRYPOINT(truncf)(float x) { return fputil::trunc(x); }
+
+} // namespace __llvm_libc

libc/test/src/math/CMakeLists.txt

SRCS
     fabsf_test.cpp
   DEPENDS
     libc.include.math
     libc.src.math.fabsf
     libc.utils.FPUtil.fputil
 )
 
 add_math_unittest(
+  trunc_test
+  NEED_MPFR
+  SUITE
+    libc_math_unittests
+  SRCS
+    trunc_test.cpp
+  DEPENDS
+    libc.include.math
+    libc.src.math.trunc
+    libc.utils.FPUtil.fputil
+)
+
+add_math_unittest(
+  truncf_test
+  NEED_MPFR
+  SUITE
+    libc_math_unittests
+  SRCS
+    truncf_test.cpp
+  DEPENDS
+    libc.include.math
+    libc.src.math.truncf
+    libc.utils.FPUtil.fputil
+)
+
+add_math_unittest(
+  ceil_test
+  NEED_MPFR
+  SUITE
+    libc_math_unittests
+  SRCS
+    ceil_test.cpp
+  DEPENDS
+    libc.include.math
+    libc.src.math.ceil
+    libc.utils.FPUtil.fputil
+)
+
+add_math_unittest(
+  ceilf_test
+  NEED_MPFR
+  SUITE
+    libc_math_unittests
+  SRCS
+    ceilf_test.cpp
+  DEPENDS
+    libc.include.math
+    libc.src.math.ceilf
+    libc.utils.FPUtil.fputil
+)
+
+add_math_unittest(
+  floor_test
+  NEED_MPFR
+  SUITE
+    libc_math_unittests
+  SRCS
+    floor_test.cpp
+  DEPENDS
+    libc.include.math
+    libc.src.math.floor
+    libc.utils.FPUtil.fputil
+)
+
+add_math_unittest(
+  floorf_test
+  NEED_MPFR
+  SUITE
+    libc_math_unittests
+  SRCS
+    floorf_test.cpp
+  DEPENDS
+    libc.include.math
+    libc.src.math.floorf
+    libc.utils.FPUtil.fputil
+)
+
+add_math_unittest(
   expf_test
   NEED_MPFR
   SUITE
     libc_math_unittests
   SRCS
     expf_test.cpp
   DEPENDS
     libc.include.errno

libc/test/src/math/ceil_test.cpp

+//===-- Unittests for ceil ------------------------------------------------===//
+//
+// 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 "include/math.h"
+#include "src/math/ceil.h"
+#include "utils/FPUtil/BitPatterns.h"
+#include "utils/FPUtil/FloatOperations.h"
+#include "utils/FPUtil/FloatProperties.h"
+#include "utils/MPFRWrapper/MPFRUtils.h"
+#include "utils/UnitTest/Test.h"
+
+using __llvm_libc::fputil::valueAsBits;
+using __llvm_libc::fputil::valueFromBits;
+
+using BitPatterns = __llvm_libc::fputil::BitPatterns<double>;
+using Properties = __llvm_libc::fputil::FloatProperties<double>;
+
+namespace mpfr = __llvm_libc::testing::mpfr;
+
+// Zero tolerance; As in, exact match with MPFR result.
+static constexpr mpfr::Tolerance tolerance{mpfr::Tolerance::doublePrecision, 0,
+                                           0};
+
+TEST(ceilTest, SpecialNumbers) {
+  EXPECT_EQ(
+      BitPatterns::aQuietNaN,
+      valueAsBits(__llvm_libc::ceil(valueFromBits(BitPatterns::aQuietNaN))));
+  EXPECT_EQ(BitPatterns::aNegativeQuietNaN,
+            valueAsBits(__llvm_libc::ceil(
+                valueFromBits(BitPatterns::aNegativeQuietNaN))));
+
+  EXPECT_EQ(BitPatterns::aSignallingNaN,
+            valueAsBits(
+                __llvm_libc::ceil(valueFromBits(BitPatterns::aSignallingNaN))));
+  EXPECT_EQ(BitPatterns::aNegativeSignallingNaN,
+            valueAsBits(__llvm_libc::ceil(
+                valueFromBits(BitPatterns::aNegativeSignallingNaN))));
+
+  EXPECT_EQ(BitPatterns::inf,
+            valueAsBits(__llvm_libc::ceil(valueFromBits(BitPatterns::inf))));
+  EXPECT_EQ(BitPatterns::negInf,
+            valueAsBits(__llvm_libc::ceil(valueFromBits(BitPatterns::negInf))));
+
+  EXPECT_EQ(BitPatterns::zero,
+            valueAsBits(__llvm_libc::ceil(valueFromBits(BitPatterns::zero))));
+  EXPECT_EQ(BitPatterns::negZero, valueAsBits(__llvm_libc::ceil(
+                                      valueFromBits(BitPatterns::negZero))));
+}
+
+TEST(ceilTest, RoundedNumbers) {
+  EXPECT_EQ(valueAsBits(1.0), valueAsBits(__llvm_libc::ceil(1.0)));
+  EXPECT_EQ(valueAsBits(-1.0), valueAsBits(__llvm_libc::ceil(-1.0)));
+  EXPECT_EQ(valueAsBits(10.0), valueAsBits(__llvm_libc::ceil(10.0)));
+  EXPECT_EQ(valueAsBits(-10.0), valueAsBits(__llvm_libc::ceil(-10.0)));
+  EXPECT_EQ(valueAsBits(12345.0), valueAsBits(__llvm_libc::ceil(12345.0)));
+  EXPECT_EQ(valueAsBits(-12345.0), valueAsBits(__llvm_libc::ceil(-12345.0)));
+}
+
+TEST(ceilTest, InDoubleRange) {
+  using BitsType = Properties::BitsType;
+  constexpr BitsType count = 1000000;
+  constexpr BitsType step = UINT64_MAX / count;
+  for (BitsType i = 0, v = 0; i <= count; ++i, v += step) {
+    double x = valueFromBits(v);
+    if (isnan(x) || isinf(x))
+      continue;
+    ASSERT_MPFR_MATCH(mpfr::Operation::Ceil, x, __llvm_libc::ceil(x),
+                      tolerance);
+  }
+}

libc/test/src/math/ceilf_test.cpp

+//===-- Unittests for ceilf -----------------------------------------------===//
+//
+// 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 "include/math.h"
+#include "src/math/ceilf.h"
+#include "utils/FPUtil/BitPatterns.h"
+#include "utils/FPUtil/FloatOperations.h"
+#include "utils/FPUtil/FloatProperties.h"
+#include "utils/MPFRWrapper/MPFRUtils.h"
+#include "utils/UnitTest/Test.h"
+
+using __llvm_libc::fputil::valueAsBits;
+using __llvm_libc::fputil::valueFromBits;
+
+using BitPatterns = __llvm_libc::fputil::BitPatterns<float>;
+using Properties = __llvm_libc::fputil::FloatProperties<float>;
+
+namespace mpfr = __llvm_libc::testing::mpfr;
+
+// Zero tolerance; As in, exact match with MPFR result.
+static constexpr mpfr::Tolerance tolerance{mpfr::Tolerance::doublePrecision, 0,
+                                           0};
+
+TEST(CeilfTest, SpecialNumbers) {
+  EXPECT_EQ(
+      BitPatterns::aQuietNaN,
+      valueAsBits(__llvm_libc::ceilf(valueFromBits(BitPatterns::aQuietNaN))));
+  EXPECT_EQ(BitPatterns::aNegativeQuietNaN,
+            valueAsBits(__llvm_libc::ceilf(
+                valueFromBits(BitPatterns::aNegativeQuietNaN))));
+
+  EXPECT_EQ(BitPatterns::aSignallingNaN,
+            valueAsBits(__llvm_libc::ceilf(
+                valueFromBits(BitPatterns::aSignallingNaN))));
+  EXPECT_EQ(BitPatterns::aNegativeSignallingNaN,
+            valueAsBits(__llvm_libc::ceilf(
+                valueFromBits(BitPatterns::aNegativeSignallingNaN))));
+
+  EXPECT_EQ(BitPatterns::inf,
+            valueAsBits(__llvm_libc::ceilf(valueFromBits(BitPatterns::inf))));
+  EXPECT_EQ(BitPatterns::negInf, valueAsBits(__llvm_libc::ceilf(
+                                     valueFromBits(BitPatterns::negInf))));
+
+  EXPECT_EQ(BitPatterns::zero,
+            valueAsBits(__llvm_libc::ceilf(valueFromBits(BitPatterns::zero))));
+  EXPECT_EQ(BitPatterns::negZero, valueAsBits(__llvm_libc::ceilf(
+                                      valueFromBits(BitPatterns::negZero))));
+}
+
+TEST(ceilfTest, RoundedNumbers) {
+  EXPECT_EQ(valueAsBits(1.0f), valueAsBits(__llvm_libc::ceilf(1.0f)));
+  EXPECT_EQ(valueAsBits(-1.0f), valueAsBits(__llvm_libc::ceilf(-1.0f)));
+  EXPECT_EQ(valueAsBits(10.0f), valueAsBits(__llvm_libc::ceilf(10.0f)));
+  EXPECT_EQ(valueAsBits(-10.0f), valueAsBits(__llvm_libc::ceilf(-10.0f)));
+  EXPECT_EQ(valueAsBits(12345.0f), valueAsBits(__llvm_libc::ceilf(12345.0f)));
+  EXPECT_EQ(valueAsBits(-12345.0f), valueAsBits(__llvm_libc::ceilf(-12345.0f)));
+}
+
+TEST(ceilfTest, InFloatRange) {
+  using BitsType = Properties::BitsType;
+  constexpr BitsType count = 1000000;
+  constexpr BitsType step = UINT32_MAX / count;
+  for (BitsType i = 0, v = 0; i <= count; ++i, v += step) {
+    double x = valueFromBits(v);
+    if (isnan(x) || isinf(x))
+      continue;
+    ASSERT_MPFR_MATCH(mpfr::Operation::Ceil, x, __llvm_libc::ceilf(x),
+                      tolerance);
+  }
+}

libc/test/src/math/floor_test.cpp

+//===-- Unittests for floor -----------------------------------------------===//
+//
+// 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 "include/math.h"
+#include "src/math/floor.h"
+#include "utils/FPUtil/BitPatterns.h"
+#include "utils/FPUtil/FloatOperations.h"
+#include "utils/FPUtil/FloatProperties.h"
+#include "utils/MPFRWrapper/MPFRUtils.h"
+#include "utils/UnitTest/Test.h"
+
+using __llvm_libc::fputil::valueAsBits;
+using __llvm_libc::fputil::valueFromBits;
+
+using BitPatterns = __llvm_libc::fputil::BitPatterns<double>;
+using Properties = __llvm_libc::fputil::FloatProperties<double>;
+
+namespace mpfr = __llvm_libc::testing::mpfr;
+
+// Zero tolerance; As in, exact match with MPFR result.
+static constexpr mpfr::Tolerance tolerance{mpfr::Tolerance::doublePrecision, 0,
+                                           0};
+
+TEST(FloorTest, SpecialNumbers) {
+  EXPECT_EQ(
+      BitPatterns::aQuietNaN,
+      valueAsBits(__llvm_libc::floor(valueFromBits(BitPatterns::aQuietNaN))));
+  EXPECT_EQ(BitPatterns::aNegativeQuietNaN,
+            valueAsBits(__llvm_libc::floor(
+                valueFromBits(BitPatterns::aNegativeQuietNaN))));
+
+  EXPECT_EQ(BitPatterns::aSignallingNaN,
+            valueAsBits(__llvm_libc::floor(
+                valueFromBits(BitPatterns::aSignallingNaN))));
+  EXPECT_EQ(BitPatterns::aNegativeSignallingNaN,
+            valueAsBits(__llvm_libc::floor(
+                valueFromBits(BitPatterns::aNegativeSignallingNaN))));
+
+  EXPECT_EQ(BitPatterns::inf,
+            valueAsBits(__llvm_libc::floor(valueFromBits(BitPatterns::inf))));
+  EXPECT_EQ(BitPatterns::negInf, valueAsBits(__llvm_libc::floor(
+                                     valueFromBits(BitPatterns::negInf))));
+
+  EXPECT_EQ(BitPatterns::zero,
+            valueAsBits(__llvm_libc::floor(valueFromBits(BitPatterns::zero))));
+  EXPECT_EQ(BitPatterns::negZero, valueAsBits(__llvm_libc::floor(
+                                      valueFromBits(BitPatterns::negZero))));
+}
+
+TEST(floorTest, RoundedNumbers) {
+  EXPECT_EQ(valueAsBits(1.0), valueAsBits(__llvm_libc::floor(1.0)));
+  EXPECT_EQ(valueAsBits(-1.0), valueAsBits(__llvm_libc::floor(-1.0)));
+  EXPECT_EQ(valueAsBits(10.0), valueAsBits(__llvm_libc::floor(10.0)));
+  EXPECT_EQ(valueAsBits(-10.0), valueAsBits(__llvm_libc::floor(-10.0)));
+  EXPECT_EQ(valueAsBits(12345.0), valueAsBits(__llvm_libc::floor(12345.0)));
+  EXPECT_EQ(valueAsBits(-12345.0), valueAsBits(__llvm_libc::floor(-12345.0)));
+}
+
+TEST(floorTest, InDoubleRange) {
+  using BitsType = Properties::BitsType;
+  constexpr BitsType count = 1000000;
+  constexpr BitsType step = UINT64_MAX / count;
+  for (BitsType i = 0, v = 0; i <= count; ++i, v += step) {
+    double x = valueFromBits(v);
+    if (isnan(x) || isinf(x))
+      continue;
+    ASSERT_MPFR_MATCH(mpfr::Operation::Floor, x, __llvm_libc::floor(x),
+                      tolerance);
+  }
+}

libc/test/src/math/floorf_test.cpp

+//===-- Unittests for floorf ----------------------------------------------===//
+//
+// 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 "include/math.h"
+#include "src/math/floorf.h"
+#include "utils/FPUtil/BitPatterns.h"
+#include "utils/FPUtil/FloatOperations.h"
+#include "utils/FPUtil/FloatProperties.h"
+#include "utils/MPFRWrapper/MPFRUtils.h"
+#include "utils/UnitTest/Test.h"
+
+using __llvm_libc::fputil::valueAsBits;
+using __llvm_libc::fputil::valueFromBits;
+
+using BitPatterns = __llvm_libc::fputil::BitPatterns<float>;
+using Properties = __llvm_libc::fputil::FloatProperties<float>;
+
+namespace mpfr = __llvm_libc::testing::mpfr;
+
+// Zero tolerance; As in, exact match with MPFR result.
+static constexpr mpfr::Tolerance tolerance{mpfr::Tolerance::doublePrecision, 0,
+                                           0};
+
+TEST(FloorfTest, SpecialNumbers) {
+  EXPECT_EQ(
+      BitPatterns::aQuietNaN,
+      valueAsBits(__llvm_libc::floorf(valueFromBits(BitPatterns::aQuietNaN))));
+  EXPECT_EQ(BitPatterns::aNegativeQuietNaN,
+            valueAsBits(__llvm_libc::floorf(
+                valueFromBits(BitPatterns::aNegativeQuietNaN))));
+
+  EXPECT_EQ(BitPatterns::aSignallingNaN,
+            valueAsBits(__llvm_libc::floorf(
+                valueFromBits(BitPatterns::aSignallingNaN))));
+  EXPECT_EQ(BitPatterns::aNegativeSignallingNaN,
+            valueAsBits(__llvm_libc::floorf(
+                valueFromBits(BitPatterns::aNegativeSignallingNaN))));
+
+  EXPECT_EQ(BitPatterns::inf,
+            valueAsBits(__llvm_libc::floorf(valueFromBits(BitPatterns::inf))));
+  EXPECT_EQ(BitPatterns::negInf, valueAsBits(__llvm_libc::floorf(
+                                     valueFromBits(BitPatterns::negInf))));
+
+  EXPECT_EQ(BitPatterns::zero,
+            valueAsBits(__llvm_libc::floorf(valueFromBits(BitPatterns::zero))));
+  EXPECT_EQ(BitPatterns::negZero, valueAsBits(__llvm_libc::floorf(
+                                      valueFromBits(BitPatterns::negZero))));
+}
+
+TEST(floorfTest, RoundedNumbers) {
+  EXPECT_EQ(valueAsBits(1.0f), valueAsBits(__llvm_libc::floorf(1.0f)));
+  EXPECT_EQ(valueAsBits(-1.0f), valueAsBits(__llvm_libc::floorf(-1.0f)));
+  EXPECT_EQ(valueAsBits(10.0f), valueAsBits(__llvm_libc::floorf(10.0f)));
+  EXPECT_EQ(valueAsBits(-10.0f), valueAsBits(__llvm_libc::floorf(-10.0f)));
+  EXPECT_EQ(valueAsBits(12345.0f), valueAsBits(__llvm_libc::floorf(12345.0f)));
+  EXPECT_EQ(valueAsBits(-12345.0f),
+            valueAsBits(__llvm_libc::floorf(-12345.0f)));
+}
+
+TEST(floorfTest, InFloatRange) {
+  using BitsType = Properties::BitsType;
+  constexpr BitsType count = 1000000;
+  constexpr BitsType step = UINT32_MAX / count;
+  for (BitsType i = 0, v = 0; i <= count; ++i, v += step) {
+    double x = valueFromBits(v);
+    if (isnan(x) || isinf(x))
+      continue;
+    ASSERT_MPFR_MATCH(mpfr::Operation::Floor, x, __llvm_libc::floorf(x),
+                      tolerance);
+  }
+}

libc/test/src/math/trunc_test.cpp

+//===-- Unittests for trunc -----------------------------------------------===//
+//
+// 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 "include/math.h"
+#include "src/math/trunc.h"
+#include "utils/FPUtil/BitPatterns.h"
+#include "utils/FPUtil/FloatOperations.h"
+#include "utils/FPUtil/FloatProperties.h"
+#include "utils/MPFRWrapper/MPFRUtils.h"
+#include "utils/UnitTest/Test.h"
+
+using __llvm_libc::fputil::valueAsBits;
+using __llvm_libc::fputil::valueFromBits;
+
+using BitPatterns = __llvm_libc::fputil::BitPatterns<double>;
+using Properties = __llvm_libc::fputil::FloatProperties<double>;
+
+namespace mpfr = __llvm_libc::testing::mpfr;
+
+// Zero tolerance; As in, exact match with MPFR result.
+static constexpr mpfr::Tolerance tolerance{mpfr::Tolerance::doublePrecision, 0,
+                                           0};
+
+TEST(TruncTest, SpecialNumbers) {
+  EXPECT_EQ(
+      BitPatterns::aQuietNaN,
+      valueAsBits(__llvm_libc::trunc(valueFromBits(BitPatterns::aQuietNaN))));
+  EXPECT_EQ(BitPatterns::aNegativeQuietNaN,
+            valueAsBits(__llvm_libc::trunc(
+                valueFromBits(BitPatterns::aNegativeQuietNaN))));
+
+  EXPECT_EQ(BitPatterns::aSignallingNaN,
+            valueAsBits(__llvm_libc::trunc(
+                valueFromBits(BitPatterns::aSignallingNaN))));
+  EXPECT_EQ(BitPatterns::aNegativeSignallingNaN,
+            valueAsBits(__llvm_libc::trunc(
+                valueFromBits(BitPatterns::aNegativeSignallingNaN))));
+
+  EXPECT_EQ(BitPatterns::inf,
+            valueAsBits(__llvm_libc::trunc(valueFromBits(BitPatterns::inf))));
+  EXPECT_EQ(BitPatterns::negInf, valueAsBits(__llvm_libc::trunc(
+                                     valueFromBits(BitPatterns::negInf))));
+
+  EXPECT_EQ(BitPatterns::zero,
+            valueAsBits(__llvm_libc::trunc(valueFromBits(BitPatterns::zero))));
+  EXPECT_EQ(BitPatterns::negZero, valueAsBits(__llvm_libc::trunc(
+                                      valueFromBits(BitPatterns::negZero))));
+}
+
+TEST(TruncTest, RoundedNumbers) {
+  EXPECT_EQ(valueAsBits(1.0), valueAsBits(__llvm_libc::trunc(1.0)));
+  EXPECT_EQ(valueAsBits(-1.0), valueAsBits(__llvm_libc::trunc(-1.0)));
+  EXPECT_EQ(valueAsBits(10.0), valueAsBits(__llvm_libc::trunc(10.0)));
+  EXPECT_EQ(valueAsBits(-10.0), valueAsBits(__llvm_libc::trunc(-10.0)));
+  EXPECT_EQ(valueAsBits(12345.0), valueAsBits(__llvm_libc::trunc(12345.0)));
+  EXPECT_EQ(valueAsBits(-12345.0), valueAsBits(__llvm_libc::trunc(-12345.0)));
+}
+
+TEST(truncTest, InDoubleRange) {
+  using BitsType = Properties::BitsType;
+  constexpr BitsType count = 1000000;
+  constexpr BitsType step = UINT64_MAX / count;
+  for (BitsType i = 0, v = 0; i <= count; ++i, v += step) {
+    double x = valueFromBits(v);
+    if (isnan(x) || isinf(x))
+      continue;
+    ASSERT_MPFR_MATCH(mpfr::Operation::Trunc, x, __llvm_libc::trunc(x),
+                      tolerance);
+  }
+}

libc/test/src/math/truncf_test.cpp

+//===-- Unittests for truncf ----------------------------------------------===//
+//
+// 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 "include/math.h"
+#include "src/math/truncf.h"
+#include "utils/FPUtil/BitPatterns.h"
+#include "utils/FPUtil/FloatOperations.h"
+#include "utils/FPUtil/FloatProperties.h"
+#include "utils/MPFRWrapper/MPFRUtils.h"
+#include "utils/UnitTest/Test.h"
+
+using __llvm_libc::fputil::valueAsBits;
+using __llvm_libc::fputil::valueFromBits;
+
+using BitPatterns = __llvm_libc::fputil::BitPatterns<float>;
+using Properties = __llvm_libc::fputil::FloatProperties<float>;
+
+namespace mpfr = __llvm_libc::testing::mpfr;
+
+// Zero tolerance; As in, exact match with MPFR result.
+static constexpr mpfr::Tolerance tolerance{mpfr::Tolerance::floatPrecision, 0,
+                                           0};
+
+namespace mpfr = __llvm_libc::testing::mpfr;
+TEST(TruncfTest, SpecialNumbers) {
+  EXPECT_EQ(
+      BitPatterns::aQuietNaN,
+      valueAsBits(__llvm_libc::truncf(valueFromBits(BitPatterns::aQuietNaN))));
+  EXPECT_EQ(BitPatterns::aNegativeQuietNaN,
+            valueAsBits(__llvm_libc::truncf(
+                valueFromBits(BitPatterns::aNegativeQuietNaN))));
+
+  EXPECT_EQ(BitPatterns::aSignallingNaN,
+            valueAsBits(__llvm_libc::truncf(
+                valueFromBits(BitPatterns::aSignallingNaN))));
+  EXPECT_EQ(BitPatterns::aNegativeSignallingNaN,
+            valueAsBits(__llvm_libc::truncf(
+                valueFromBits(BitPatterns::aNegativeSignallingNaN))));
+
+  EXPECT_EQ(BitPatterns::inf,
+            valueAsBits(__llvm_libc::truncf(valueFromBits(BitPatterns::inf))));
+  EXPECT_EQ(BitPatterns::negInf, valueAsBits(__llvm_libc::truncf(
+                                     valueFromBits(BitPatterns::negInf))));
+
+  EXPECT_EQ(BitPatterns::zero,
+            valueAsBits(__llvm_libc::truncf(valueFromBits(BitPatterns::zero))));
+  EXPECT_EQ(BitPatterns::negZero, valueAsBits(__llvm_libc::truncf(
+                                      valueFromBits(BitPatterns::negZero))));
+}
+
+TEST(TruncTest, RoundedNumbers) {
+  EXPECT_EQ(valueAsBits(1.0f), valueAsBits(__llvm_libc::truncf(1.0f)));
+  EXPECT_EQ(valueAsBits(-1.0f), valueAsBits(__llvm_libc::truncf(-1.0f)));
+  EXPECT_EQ(valueAsBits(10.0f), valueAsBits(__llvm_libc::truncf(10.0f)));
+  EXPECT_EQ(valueAsBits(-10.0f), valueAsBits(__llvm_libc::truncf(-10.0f)));
+  EXPECT_EQ(valueAsBits(12345.0f), valueAsBits(__llvm_libc::truncf(12345.0f)));
+  EXPECT_EQ(valueAsBits(-12345.0f),
+            valueAsBits(__llvm_libc::truncf(-12345.0f)));
+}
+
+TEST(truncfTest, InFloatRange) {
+  using BitsType = Properties::BitsType;
+  constexpr BitsType count = 1000000;
+  constexpr BitsType step = UINT32_MAX / count;
+  for (BitsType i = 0, v = 0; i <= count; ++i, v += step) {
+    double x = valueFromBits(v);
+    if (isnan(x) || isinf(x))
+      continue;
+    ASSERT_MPFR_MATCH(mpfr::Operation::Trunc, x, __llvm_libc::truncf(x),
+                      tolerance);
+  }
+}

libc/utils/FPUtil/FloatOperations.h

 
 // Return the bits of abs(x).
 template <typename T,
           cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
 static inline typename FloatProperties<T>::BitsType absBits(T x) {
   return valueAsBits(x) & (~FloatProperties<T>::signMask);
 }
 
-// Return the zero adjusted exponent value of x.
-template <typename T,
-          cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
-int getExponent(T x) {
-  using Properties = FloatProperties<T>;
-  using BitsType = typename Properties::BitsType;
-  BitsType bits = absBits(x);
+template <typename BitsType>
+static inline int getExponentFromBits(BitsType bits) {
+  using FPType = typename FloatType<BitsType>::Type;
+  using Properties = FloatProperties<FPType>;
+  bits = bits & Properties::exponentMask;
   int e = (bits >> Properties::mantissaWidth); // Shift out the mantissa.
   e -= Properties::exponentOffset;             // Zero adjust.
   return e;
 }
 
+// Return the zero adjusted exponent value of x.
+template <typename T,
+          cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
+static inline int getExponent(T x) {
+  return getExponentFromBits(valueAsBits(x));
+}
+
 // Return true if x is infinity (positive or negative.)
 template <typename T,
           cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
 static inline bool isInf(T x) {
   using Properties = FloatProperties<T>;
   using BitsType = typename FloatProperties<T>::BitsType;
   BitsType bits = valueAsBits(x);
   return ((bits & BitPatterns<T>::inf) == BitPatterns<T>::inf) &&
          ((bits & Properties::mantissaMask) == 0);
 }
 
 // Return true if x is a NAN (quiet or signalling.)
 template <typename T,
           cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
 static inline bool isNaN(T x) {
   using Properties = FloatProperties<T>;
   using BitsType = typename FloatProperties<T>::BitsType;
   BitsType bits = valueAsBits(x);
   return ((bits & BitPatterns<T>::inf) == BitPatterns<T>::inf) &&
          ((bits & Properties::mantissaMask) != 0);
 }
 
+template <typename BitsType> static inline bool bitsAreInfOrNaN(BitsType bits) {
+  using FPType = typename FloatType<BitsType>::Type;
+  return (bits & BitPatterns<FPType>::inf) == BitPatterns<FPType>::inf;
+}
+
+template <typename BitsType> static inline bool bitsAreZero(BitsType bits) {
+  using FPType = typename FloatType<BitsType>::Type;
+  return (bits == BitPatterns<FPType>::zero) ||
+         (bits == BitPatterns<FPType>::negZero);
+}
+
+// Return true if x is any kind of NaN or infinity.
+template <typename T,
+          cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
+static inline bool isInfOrNaN(T x) {
+  return bitsAreInfOrNaN(valueAsBits(x));
+}
+
 // Return true if x is a quiet NAN.
 template <typename T,
           cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
 static inline bool isQuietNaN(T x) {
   using Properties = FloatProperties<T>;
   using BitsType = typename FloatProperties<T>::BitsType;
   BitsType bits = valueAsBits(x);
   return ((bits & BitPatterns<T>::inf) == BitPatterns<T>::inf) &&

 
 // Return the absolute value of x.
 template <typename T,
           cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
 static inline T abs(T x) {
   return valueFromBits(absBits(x));
 }
 
+// Return the trucated value of x. If x is non-negative, then the return value
+// is greatest integer less than or equal to x. Otherwise, return the smallest
+// integer greater than or equal to x. That is, return the integer value rounded
+// toward zero.
+template <typename T,
+          cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
+static inline T trunc(T x) {
+  using Properties = FloatProperties<T>;
+  using BitsType = typename FloatProperties<T>::BitsType;
+
+  BitsType bits = valueAsBits(x);
+
+  // If x is infinity, NaN or zero, return it.
+  if (bitsAreInfOrNaN(bits) || bitsAreZero(bits))
+    return x;
+
+  int exponent = getExponentFromBits(bits);
+
+  // If the exponent is greater than the most negative mantissa
+  // exponent, then x is already an integer.
+  if (exponent >= static_cast<int>(Properties::mantissaWidth))
+    return x;
+
+  // If the exponent is such that abs(x) is less than 1, then return 0.
+  if (exponent <= -1) {
+    if (Properties::signMask & bits)
+      return T(-0.0);
+    else
+      return T(0.0);
+  }
+
+  uint32_t trimSize = Properties::mantissaWidth - exponent;
+  return valueFromBits((bits >> trimSize) << trimSize);
+}
+
+template <typename T,
+          cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
+static inline T ceil(T x) {
+  using Properties = FloatProperties<T>;
+  using BitsType = typename FloatProperties<T>::BitsType;
+
+  BitsType bits = valueAsBits(x);
+
+  // If x is infinity NaN or zero, return it.
+  if (bitsAreInfOrNaN(bits) || bitsAreZero(bits))
+    return x;
+
+  bool isNeg = bits & Properties::signMask;
+  int exponent = getExponentFromBits(bits);
+
+  // If the exponent is greater than the most negative mantissa
+  // exponent, then x is already an integer.
+  if (exponent >= static_cast<int>(Properties::mantissaWidth))
+    return x;
+
+  if (exponent <= -1) {
+    if (isNeg)
+      return T(-0.0);
+    else
+      return T(1.0);
+  }
+
+  uint32_t trimSize = Properties::mantissaWidth - exponent;
+  // If x is already an integer, return it.
+  if ((bits << (Properties::bitWidth - trimSize)) == 0)
+    return x;
+
+  BitsType truncBits = (bits >> trimSize) << trimSize;
+  T truncValue = valueFromBits(truncBits);
+
+  // If x is negative, the ceil operation is equivalent to the trunc operation.
+  if (isNeg)
+    return truncValue;
+
+  return truncValue + T(1.0);
+}
+
+template <typename T,
+          cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
+static inline T floor(T x) {
+  auto bits = valueAsBits(x);
+  if (FloatProperties<T>::signMask & bits) {
+    return -ceil(-x);
+  } else {
+    return trunc(x);
+  }
+}
+
 } // namespace fputil
 } // namespace __llvm_libc
 
 #endif // LLVM_LIBC_UTILS_FPUTIL_FLOAT_OPERATIONS_H

libc/utils/FPUtil/FloatProperties.h

 
 template <typename T> struct FloatProperties {};
 
 template <> struct FloatProperties<float> {
   typedef uint32_t BitsType;
   static_assert(sizeof(BitsType) == sizeof(float),
                 "Unexpected size of 'float' type.");
 
+  static constexpr uint32_t bitWidth = sizeof(BitsType) << 3;
+
   static constexpr uint32_t mantissaWidth = 23;
   static constexpr BitsType mantissaMask = 0x007fffffU;
   static constexpr BitsType signMask = 0x80000000U;
+  static constexpr BitsType exponentMask = ~(signMask | mantissaMask);
   static constexpr uint32_t exponentOffset = 127;
 
   // If a number x is a NAN, then it is a quiet NAN if:
   //   QuietNaNMask & bits(x) != 0
   // Else, it is a signalling NAN.
   static constexpr BitsType quietNaNMask = 0x00400000U;
 };
 
 template <> struct FloatProperties<double> {
   typedef uint64_t BitsType;
   static_assert(sizeof(BitsType) == sizeof(double),
                 "Unexpected size of 'double' type.");
 
+  static constexpr uint32_t bitWidth = sizeof(BitsType) << 3;
+
   static constexpr uint32_t mantissaWidth = 52;
   static constexpr BitsType mantissaMask = 0x000fffffffffffffU;
   static constexpr BitsType signMask = 0x8000000000000000ULL;
+  static constexpr BitsType exponentMask = ~(signMask | mantissaMask);
   static constexpr uint32_t exponentOffset = 1023;
 
   // If a number x is a NAN, then it is a quiet NAN if:
   //   QuietNaNMask & bits(x) != 0
   // Else, it is a signalling NAN.
   static constexpr BitsType quietNaNMask = 0x0008000000000000ULL;
 };
 

libc/utils/MPFRWrapper/MPFRUtils.h

struct Tolerance {
   unsigned int width; // Number of valid LSB bits in |value|.
 
   // The bits in the tolerance value. The tolerance value will be
   // sum(bits[width - i] * 2 ^ (- basePrecision - i)) for |i| in
   // range [1, width].
   uint32_t bits;
 };
 
-enum class Operation : int { Abs, Cos, Exp, Exp2, Sin };
+enum class Operation : int {
+  Abs,
+  Ceil,
+  Cos,
+  Exp,
+  Exp2,
+  Floor,
+  Round,
+  Sin,
+  Trunc
+};
 
 namespace internal {
 
 template <typename T>
 bool compare(Operation op, T input, T libcOutput, const Tolerance &t);
 
 template <typename T> class MPFRMatcher : public testing::Matcher<T> {
   static_assert(__llvm_libc::cpp::IsFloatingPointType<T>::Value,

libc/utils/MPFRWrapper/MPFRUtils.cpp

template <typename XType,
             cpp::EnableIfType<cpp::IsFloatingPointType<XType>::Value, int> = 0>
   MPFRNumber(Operation op, XType rawValue) {
     mpfr_init2(value, mpfrPrecision);
     MPFRNumber mpfrInput(rawValue);
     switch (op) {
     case Operation::Abs:
       mpfr_abs(value, mpfrInput.value, MPFR_RNDN);
       break;
+    case Operation::Ceil:
+      mpfr_ceil(value, mpfrInput.value);
+      break;
     case Operation::Cos:
       mpfr_cos(value, mpfrInput.value, MPFR_RNDN);
       break;
     case Operation::Exp:
       mpfr_exp(value, mpfrInput.value, MPFR_RNDN);
       break;
     case Operation::Exp2:
       mpfr_exp2(value, mpfrInput.value, MPFR_RNDN);
       break;
+    case Operation::Floor:
+      mpfr_floor(value, mpfrInput.value);
+      break;
+    case Operation::Round:
+      mpfr_round(value, mpfrInput.value);
+      break;
     case Operation::Sin:
       mpfr_sin(value, mpfrInput.value, MPFR_RNDN);
       break;
+    case Operation::Trunc:
+      mpfr_trunc(value, mpfrInput.value);
+      break;
     }
   }
 
   MPFRNumber(const MPFRNumber &other) {
     mpfr_set(value, other.value, MPFR_RNDN);
   }
 
   ~MPFRNumber() { mpfr_clear(value); }