[llvm-branch-commits] [libc] [libc][math][c23] Add tanhf16 C23 math function (PR #106006)
via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Tue Oct 15 06:49:39 PDT 2024
https://github.com/overmighty updated https://github.com/llvm/llvm-project/pull/106006
>From 1a0ef1066e233c275133c6c75e3ba6631a2edadf Mon Sep 17 00:00:00 2001
From: OverMighty <its.overmighty at gmail.com>
Date: Sun, 25 Aug 2024 22:02:09 +0200
Subject: [PATCH 1/2] [libc][math][c23] Add tanhf16 C23 math function
Part of #95250.
---
libc/config/gpu/entrypoints.txt | 1 +
libc/config/linux/x86_64/entrypoints.txt | 1 +
libc/docs/math/index.rst | 2 +-
libc/spec/stdc.td | 1 +
libc/src/math/CMakeLists.txt | 1 +
libc/src/math/generic/CMakeLists.txt | 22 ++++
libc/src/math/generic/tanhf16.cpp | 144 ++++++++++++++++++++++
libc/src/math/tanhf16.h | 21 ++++
libc/test/src/math/CMakeLists.txt | 11 ++
libc/test/src/math/smoke/CMakeLists.txt | 12 ++
libc/test/src/math/smoke/tanhf16_test.cpp | 131 ++++++++++++++++++++
libc/test/src/math/tanhf16_test.cpp | 40 ++++++
12 files changed, 386 insertions(+), 1 deletion(-)
create mode 100644 libc/src/math/generic/tanhf16.cpp
create mode 100644 libc/src/math/tanhf16.h
create mode 100644 libc/test/src/math/smoke/tanhf16_test.cpp
create mode 100644 libc/test/src/math/tanhf16_test.cpp
diff --git a/libc/config/gpu/entrypoints.txt b/libc/config/gpu/entrypoints.txt
index 4bb81f5d3b2de1..d89093b2117c2d 100644
--- a/libc/config/gpu/entrypoints.txt
+++ b/libc/config/gpu/entrypoints.txt
@@ -587,6 +587,7 @@ if(LIBC_TYPES_HAS_FLOAT16)
libc.src.math.setpayloadf16
libc.src.math.setpayloadsigf16
libc.src.math.sinhf16
+ libc.src.math.tanhf16
libc.src.math.totalorderf16
libc.src.math.totalordermagf16
libc.src.math.truncf16
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index a8988336cb44fc..1645ff917821b3 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -680,6 +680,7 @@ if(LIBC_TYPES_HAS_FLOAT16)
libc.src.math.setpayloadf16
libc.src.math.setpayloadsigf16
libc.src.math.sinhf16
+ libc.src.math.tanhf16
libc.src.math.totalorderf16
libc.src.math.totalordermagf16
libc.src.math.truncf16
diff --git a/libc/docs/math/index.rst b/libc/docs/math/index.rst
index 29a0e6e29d8612..61c95e065b24da 100644
--- a/libc/docs/math/index.rst
+++ b/libc/docs/math/index.rst
@@ -348,7 +348,7 @@ Higher Math Functions
+-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
| tan | |check| | |check| | | | | 7.12.4.7 | F.10.1.7 |
+-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
-| tanh | |check| | | | | | 7.12.5.6 | F.10.2.6 |
+| tanh | |check| | | | |check| | | 7.12.5.6 | F.10.2.6 |
+-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
| tanpi | | | | | | 7.12.4.14 | F.10.1.14 |
+-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
index e4e46e7e13a586..196dab9f81b38e 100644
--- a/libc/spec/stdc.td
+++ b/libc/spec/stdc.td
@@ -798,6 +798,7 @@ def StdC : StandardSpec<"stdc"> {
GuardedFunctionSpec<"sinhf16", RetValSpec<Float16Type>, [ArgSpec<Float16Type>], "LIBC_TYPES_HAS_FLOAT16">,
FunctionSpec<"tanhf", RetValSpec<FloatType>, [ArgSpec<FloatType>]>,
+ GuardedFunctionSpec<"tanhf16", RetValSpec<Float16Type>, [ArgSpec<Float16Type>], "LIBC_TYPES_HAS_FLOAT16">,
FunctionSpec<"acosf", RetValSpec<FloatType>, [ArgSpec<FloatType>]>,
diff --git a/libc/src/math/CMakeLists.txt b/libc/src/math/CMakeLists.txt
index c35950d4b61823..8b9e7aeee591c7 100644
--- a/libc/src/math/CMakeLists.txt
+++ b/libc/src/math/CMakeLists.txt
@@ -495,6 +495,7 @@ add_math_entrypoint_object(tanf)
add_math_entrypoint_object(tanh)
add_math_entrypoint_object(tanhf)
+add_math_entrypoint_object(tanhf16)
add_math_entrypoint_object(tgamma)
add_math_entrypoint_object(tgammaf)
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
index c29c5d0b007419..a5d10cf7f65cc1 100644
--- a/libc/src/math/generic/CMakeLists.txt
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -4269,6 +4269,28 @@ add_entrypoint_object(
-O3
)
+add_entrypoint_object(
+ tanhf16
+ SRCS
+ tanhf16.cpp
+ HDRS
+ ../tanhf16.h
+ DEPENDS
+ .expxf16
+ libc.hdr.fenv_macros
+ libc.src.__support.CPP.array
+ libc.src.__support.FPUtil.except_value_utils
+ libc.src.__support.FPUtil.fenv_impl
+ libc.src.__support.FPUtil.fp_bits
+ libc.src.__support.FPUtil.multiply_add
+ libc.src.__support.FPUtil.nearest_integer
+ libc.src.__support.FPUtil.polyeval
+ libc.src.__support.FPUtil.rounding_mode
+ libc.src.__support.macros.optimization
+ COMPILE_OPTIONS
+ -O3
+)
+
add_entrypoint_object(
acoshf
SRCS
diff --git a/libc/src/math/generic/tanhf16.cpp b/libc/src/math/generic/tanhf16.cpp
new file mode 100644
index 00000000000000..52caa3bc49409a
--- /dev/null
+++ b/libc/src/math/generic/tanhf16.cpp
@@ -0,0 +1,144 @@
+//===-- Half-precision tanh(x) 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/math/tanhf16.h"
+#include "expxf16.h"
+#include "hdr/fenv_macros.h"
+#include "src/__support/CPP/array.h"
+#include "src/__support/FPUtil/FEnvImpl.h"
+#include "src/__support/FPUtil/FPBits.h"
+#include "src/__support/FPUtil/PolyEval.h"
+#include "src/__support/FPUtil/except_value_utils.h"
+#include "src/__support/FPUtil/multiply_add.h"
+#include "src/__support/FPUtil/nearest_integer.h"
+#include "src/__support/FPUtil/rounding_mode.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/optimization.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+static constexpr fputil::ExceptValues<float16, 2> TANHF16_EXCEPTS = {{
+ // x = 0x1.f54p+0, tanhf16(x) = 0x1.ecp-1 (RZ)
+ {0x3fd5U, 0x3bb0U, 1U, 0U, 0U},
+ // x = -0x1.f54p+0, tanhf16(x) = -0x1.ecp-1 (RZ)
+ {0xbfd5U, 0xbbb0U, 0U, 1U, 0U},
+}};
+
+LLVM_LIBC_FUNCTION(float16, tanhf16, (float16 x)) {
+ using FPBits = fputil::FPBits<float16>;
+ FPBits x_bits(x);
+
+ uint16_t x_u = x_bits.uintval();
+ uint16_t x_abs = x_u & 0x7fffU;
+
+ // When -2^(-14) <= x <= -2^(-9), or |x| <= 0x1.d2p-4,
+ // or |x| >= atanh(1 - 2^(-11)), or x is NaN.
+ if (LIBC_UNLIKELY((x_u >= 0x8400U && x_u <= 0x9800U) || x_abs <= 0x2f48U ||
+ x_abs >= 0x4429U)) {
+ // tanh(NaN) = NaN
+ if (x_bits.is_nan()) {
+ if (x_bits.is_signaling_nan()) {
+ fputil::raise_except_if_required(FE_INVALID);
+ return FPBits::quiet_nan().get_val();
+ }
+
+ return x;
+ }
+
+ // When -2^(-14) <= x <= -2^(-9).
+ if (x_u >= 0x8400U && x_u <= 0x9800U) {
+ switch (fputil::quick_get_round()) {
+ case FE_TONEAREST:
+ case FE_DOWNWARD:
+ return x;
+ default:
+ return FPBits(static_cast<uint16_t>(x_u - 1U)).get_val();
+ }
+ }
+
+ // When |x| <= 0x1.d2p-4.
+ if (x_abs <= 0x2f48U) {
+ float xf = x;
+ float xf_sq = xf * xf;
+ // Degree-7 Taylor expansion generated by Sollya with the following
+ // commands:
+ // > taylor(tanh(x), 7, 0);
+ // > display = hexadecimal;
+ // > // For each coefficient:
+ // > round(/* put coefficient here */, SG, RN);
+ return static_cast<float16>(
+ xf * fputil::polyeval(xf_sq, 0x1p+0f, -0x1.555556p-2f, 0x1.111112p-3f,
+ -0x1.ba1ba2p-5f));
+ }
+
+ // tanh(+/-inf) = +/-1
+ if (x_bits.is_inf())
+ return FPBits::one(x_bits.sign()).get_val();
+
+ // When |x| >= atanh(1 - 2^(-11)).
+ fputil::raise_except_if_required(FE_INEXACT);
+
+ int rounding_mode = fputil::quick_get_round();
+ if ((rounding_mode == FE_TONEAREST && x_abs >= 0x4482U) ||
+ (rounding_mode == FE_UPWARD && x_bits.is_pos()) ||
+ (rounding_mode == FE_DOWNWARD && x_bits.is_neg())) {
+ return FPBits::one(x_bits.sign()).get_val();
+ }
+ if (x_bits.is_pos())
+ return static_cast<float16>(0x1.ffcp-1);
+ return static_cast<float16>(-0x1.ffcp-1);
+ }
+
+ if (auto r = TANHF16_EXCEPTS.lookup(x_u); LIBC_UNLIKELY(r.has_value()))
+ return r.value();
+
+ // For atanh(-1 + 2^(-11)) < x < atanh(1 - 2^(-11)), to compute tanh(x), we
+ // perform the following range reduction: find hi, mid, lo, such that:
+ // x = (hi + mid) * log(2) * 0.5 + lo, in which
+ // hi is an integer,
+ // mid * 2^5 is an integer,
+ // -2^(-5) <= lo < 2^(-5).
+ // In particular,
+ // hi + mid = round(x * log2(e) * 2 * 2^5) * 2^(-5).
+ // Then,
+ // tanh(x) = sinh(x)/cosh(x)
+ // = (e^x - e^(-x)) / (e^x + e^(-x))
+ // = (e^(2x) - 1) / (e^(2x) + 1)
+ // = (2^(hi + mid) * e^(2*lo) - 1) / (2^(hi + mid) * e^(2*lo) + 1)
+ // = (e^(2*lo) - 2^(-hi - mid)) / (e^(2*lo) + 2^(-hi - mid))
+ // We store 2^(-mid) in the lookup table EXP2_MID_5_BITS, and compute
+ // 2^(-hi - mid) by adding -hi to the exponent field of 2^(-mid).
+ // e^lo is computed using a degree-3 minimax polynomial generated by Sollya.
+
+ float xf = x;
+ float kf = fputil::nearest_integer(xf * (LOG2F_E * 2.0f * 0x1.0p+5f));
+ int x_hi_mid = -static_cast<int>(kf);
+ int x_hi = x_hi_mid >> 5;
+ int x_mid = x_hi_mid & 0x1f;
+ // lo = x - (hi + mid)
+ // = round(x * log2(e) * 2 * 2^5) * log(2) * 0.5 * (-2^(-5)) + x
+ float lo = fputil::multiply_add(kf, LOGF_2 * 0.5f * -0x1.0p-5f, xf);
+
+ uint32_t exp2_hi_mid_bits =
+ EXP2_MID_5_BITS[x_mid] +
+ static_cast<uint32_t>(x_hi << fputil::FPBits<float>::FRACTION_LEN);
+ // exp2_hi_mid = 2^(-hi - mid)
+ float exp2_hi_mid = fputil::FPBits<float>(exp2_hi_mid_bits).get_val();
+ // Degree-3 minimax polynomial generated by Sollya with the following
+ // commands:
+ // > display = hexadecimal;
+ // > P = fpminimax(expm1(2*x)/x, 2, [|SG...|], [-2^-5, 2^-5]);
+ // > 1 + x * P;
+ float exp_2lo =
+ fputil::polyeval(lo, 0x1p+0f, 0x1p+1f, 0x1.001p+1f, 0x1.555ddep+0f);
+ return static_cast<float16>((exp_2lo - exp2_hi_mid) /
+ (exp_2lo + exp2_hi_mid));
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/math/tanhf16.h b/libc/src/math/tanhf16.h
new file mode 100644
index 00000000000000..67498708fc462e
--- /dev/null
+++ b/libc/src/math/tanhf16.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for tanhf16 -----------------------*- 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_TANHF16_H
+#define LLVM_LIBC_SRC_MATH_TANHF16_H
+
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+float16 tanhf16(float16 x);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_MATH_TANHF16_H
diff --git a/libc/test/src/math/CMakeLists.txt b/libc/test/src/math/CMakeLists.txt
index 254d736fd998a5..d2a75bd7c8e1f9 100644
--- a/libc/test/src/math/CMakeLists.txt
+++ b/libc/test/src/math/CMakeLists.txt
@@ -1955,6 +1955,17 @@ add_fp_unittest(
libc.src.__support.FPUtil.fp_bits
)
+add_fp_unittest(
+ tanhf16_test
+ NEED_MPFR
+ SUITE
+ libc-math-unittests
+ SRCS
+ tanhf16_test.cpp
+ DEPENDS
+ libc.src.math.tanhf16
+)
+
add_fp_unittest(
atanhf_test
NEED_MPFR
diff --git a/libc/test/src/math/smoke/CMakeLists.txt b/libc/test/src/math/smoke/CMakeLists.txt
index 71fc85c88ef607..46321c022cbad3 100644
--- a/libc/test/src/math/smoke/CMakeLists.txt
+++ b/libc/test/src/math/smoke/CMakeLists.txt
@@ -3767,6 +3767,18 @@ add_fp_unittest(
libc.src.__support.FPUtil.fp_bits
)
+add_fp_unittest(
+ tanhf16_test
+ SUITE
+ libc-math-smoke-tests
+ SRCS
+ tanhf16_test.cpp
+ DEPENDS
+ libc.hdr.fenv_macros
+ libc.src.errno.errno
+ libc.src.math.tanhf16
+)
+
add_fp_unittest(
atanhf_test
SUITE
diff --git a/libc/test/src/math/smoke/tanhf16_test.cpp b/libc/test/src/math/smoke/tanhf16_test.cpp
new file mode 100644
index 00000000000000..48bbeb677541e8
--- /dev/null
+++ b/libc/test/src/math/smoke/tanhf16_test.cpp
@@ -0,0 +1,131 @@
+//===-- Unittests for tanhf16 ---------------------------------------------===//
+//
+// 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 "hdr/fenv_macros.h"
+#include "src/errno/libc_errno.h"
+#include "src/math/tanhf16.h"
+#include "test/UnitTest/FPMatcher.h"
+#include "test/UnitTest/Test.h"
+
+using LlvmLibcTanhf16Test = LIBC_NAMESPACE::testing::FPTest<float16>;
+
+TEST_F(LlvmLibcTanhf16Test, SpecialNumbers) {
+ LIBC_NAMESPACE::libc_errno = 0;
+
+ EXPECT_FP_EQ_ALL_ROUNDING(aNaN, LIBC_NAMESPACE::tanhf16(aNaN));
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION(aNaN, LIBC_NAMESPACE::tanhf16(sNaN), FE_INVALID);
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_ALL_ROUNDING(static_cast<float16>(1.0),
+ LIBC_NAMESPACE::tanhf16(inf));
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_ALL_ROUNDING(static_cast<float16>(-1.0),
+ LIBC_NAMESPACE::tanhf16(neg_inf));
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_ALL_ROUNDING(zero, LIBC_NAMESPACE::tanhf16(zero));
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_ALL_ROUNDING(neg_zero, LIBC_NAMESPACE::tanhf16(neg_zero));
+ EXPECT_MATH_ERRNO(0);
+}
+
+TEST_F(LlvmLibcTanhf16Test, ResultNearBounds) {
+ LIBC_NAMESPACE::libc_errno = 0;
+
+ EXPECT_FP_EQ_WITH_EXCEPTION(static_cast<float16>(1.0),
+ LIBC_NAMESPACE::tanhf16(max_normal), FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION(static_cast<float16>(-1.0),
+ LIBC_NAMESPACE::tanhf16(neg_max_normal),
+ FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ // round(atanh(1 - 2^-11), HP, RU);
+ float16 x = static_cast<float16>(0x1.0a4p+2);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_NEAREST(
+ static_cast<float16>(0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_UPWARD(
+ static_cast<float16>(1.0), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_DOWNWARD(
+ static_cast<float16>(0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_TOWARD_ZERO(
+ static_cast<float16>(0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ x = static_cast<float16>(0x1.208p+2);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_NEAREST(
+ static_cast<float16>(1.0), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_UPWARD(
+ static_cast<float16>(1.0), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_DOWNWARD(
+ static_cast<float16>(0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_TOWARD_ZERO(
+ static_cast<float16>(0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ // round(atanh(-1 + 2^-11), HP, RD);
+ x = static_cast<float16>(-0x1.0a4p+2);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_NEAREST(
+ static_cast<float16>(-0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x),
+ FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_UPWARD(static_cast<float16>(-0x1.ffcp-1),
+ LIBC_NAMESPACE::tanhf16(x),
+ FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_DOWNWARD(
+ static_cast<float16>(-1.0), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_TOWARD_ZERO(
+ static_cast<float16>(-0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x),
+ FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ x = static_cast<float16>(-0x1.208p+2);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_NEAREST(
+ static_cast<float16>(-1.0), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_UPWARD(static_cast<float16>(-0x1.ffcp-1),
+ LIBC_NAMESPACE::tanhf16(x),
+ FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_DOWNWARD(
+ static_cast<float16>(-1.0), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_TOWARD_ZERO(
+ static_cast<float16>(-0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x),
+ FE_INEXACT);
+ EXPECT_MATH_ERRNO(0);
+}
diff --git a/libc/test/src/math/tanhf16_test.cpp b/libc/test/src/math/tanhf16_test.cpp
new file mode 100644
index 00000000000000..7124a83f3d7bc8
--- /dev/null
+++ b/libc/test/src/math/tanhf16_test.cpp
@@ -0,0 +1,40 @@
+//===-- Exhaustive test for tanhf16 ---------------------------------------===//
+//
+// 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/math/tanhf16.h"
+#include "test/UnitTest/FPMatcher.h"
+#include "test/UnitTest/Test.h"
+#include "utils/MPFRWrapper/MPFRUtils.h"
+
+using LlvmLibcTanhf16Test = LIBC_NAMESPACE::testing::FPTest<float16>;
+
+namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
+
+// Range: [0, Inf];
+static constexpr uint16_t POS_START = 0x0000U;
+static constexpr uint16_t POS_STOP = 0x7c00U;
+
+// Range: [-Inf, 0];
+static constexpr uint16_t NEG_START = 0x8000U;
+static constexpr uint16_t NEG_STOP = 0xfc00U;
+
+TEST_F(LlvmLibcTanhf16Test, PositiveRange) {
+ for (uint16_t v = POS_START; v <= POS_STOP; ++v) {
+ float16 x = FPBits(v).get_val();
+ EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Tanh, x,
+ LIBC_NAMESPACE::tanhf16(x), 0.5);
+ }
+}
+
+TEST_F(LlvmLibcTanhf16Test, NegativeRange) {
+ for (uint16_t v = NEG_START; v <= NEG_STOP; ++v) {
+ float16 x = FPBits(v).get_val();
+ EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Tanh, x,
+ LIBC_NAMESPACE::tanhf16(x), 0.5);
+ }
+}
>From c343f44962a84cf86d2132d2b2d4ca7ab6a92c0c Mon Sep 17 00:00:00 2001
From: OverMighty <its.overmighty at gmail.com>
Date: Tue, 15 Oct 2024 15:46:53 +0200
Subject: [PATCH 2/2] Migrate to fputil::cast
---
libc/src/math/generic/CMakeLists.txt | 1 +
libc/src/math/generic/tanhf16.cpp | 11 ++--
libc/test/src/math/smoke/CMakeLists.txt | 1 +
libc/test/src/math/smoke/tanhf16_test.cpp | 74 +++++++++++++----------
4 files changed, 51 insertions(+), 36 deletions(-)
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
index a5d10cf7f65cc1..477dfd2af29e73 100644
--- a/libc/src/math/generic/CMakeLists.txt
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -4279,6 +4279,7 @@ add_entrypoint_object(
.expxf16
libc.hdr.fenv_macros
libc.src.__support.CPP.array
+ libc.src.__support.FPUtil.cast
libc.src.__support.FPUtil.except_value_utils
libc.src.__support.FPUtil.fenv_impl
libc.src.__support.FPUtil.fp_bits
diff --git a/libc/src/math/generic/tanhf16.cpp b/libc/src/math/generic/tanhf16.cpp
index 52caa3bc49409a..3b555e3ccfaaa6 100644
--- a/libc/src/math/generic/tanhf16.cpp
+++ b/libc/src/math/generic/tanhf16.cpp
@@ -13,6 +13,7 @@
#include "src/__support/FPUtil/FEnvImpl.h"
#include "src/__support/FPUtil/FPBits.h"
#include "src/__support/FPUtil/PolyEval.h"
+#include "src/__support/FPUtil/cast.h"
#include "src/__support/FPUtil/except_value_utils.h"
#include "src/__support/FPUtil/multiply_add.h"
#include "src/__support/FPUtil/nearest_integer.h"
@@ -72,7 +73,7 @@ LLVM_LIBC_FUNCTION(float16, tanhf16, (float16 x)) {
// > display = hexadecimal;
// > // For each coefficient:
// > round(/* put coefficient here */, SG, RN);
- return static_cast<float16>(
+ return fputil::cast<float16>(
xf * fputil::polyeval(xf_sq, 0x1p+0f, -0x1.555556p-2f, 0x1.111112p-3f,
-0x1.ba1ba2p-5f));
}
@@ -91,8 +92,8 @@ LLVM_LIBC_FUNCTION(float16, tanhf16, (float16 x)) {
return FPBits::one(x_bits.sign()).get_val();
}
if (x_bits.is_pos())
- return static_cast<float16>(0x1.ffcp-1);
- return static_cast<float16>(-0x1.ffcp-1);
+ return fputil::cast<float16>(0x1.ffcp-1);
+ return fputil::cast<float16>(-0x1.ffcp-1);
}
if (auto r = TANHF16_EXCEPTS.lookup(x_u); LIBC_UNLIKELY(r.has_value()))
@@ -137,8 +138,8 @@ LLVM_LIBC_FUNCTION(float16, tanhf16, (float16 x)) {
// > 1 + x * P;
float exp_2lo =
fputil::polyeval(lo, 0x1p+0f, 0x1p+1f, 0x1.001p+1f, 0x1.555ddep+0f);
- return static_cast<float16>((exp_2lo - exp2_hi_mid) /
- (exp_2lo + exp2_hi_mid));
+ return fputil::cast<float16>((exp_2lo - exp2_hi_mid) /
+ (exp_2lo + exp2_hi_mid));
}
} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/test/src/math/smoke/CMakeLists.txt b/libc/test/src/math/smoke/CMakeLists.txt
index 46321c022cbad3..b307d6caa7a1b1 100644
--- a/libc/test/src/math/smoke/CMakeLists.txt
+++ b/libc/test/src/math/smoke/CMakeLists.txt
@@ -3777,6 +3777,7 @@ add_fp_unittest(
libc.hdr.fenv_macros
libc.src.errno.errno
libc.src.math.tanhf16
+ libc.src.__support.FPUtil.cast
)
add_fp_unittest(
diff --git a/libc/test/src/math/smoke/tanhf16_test.cpp b/libc/test/src/math/smoke/tanhf16_test.cpp
index 48bbeb677541e8..fa6328e9ef0a60 100644
--- a/libc/test/src/math/smoke/tanhf16_test.cpp
+++ b/libc/test/src/math/smoke/tanhf16_test.cpp
@@ -7,6 +7,7 @@
//===----------------------------------------------------------------------===//
#include "hdr/fenv_macros.h"
+#include "src/__support/FPUtil/cast.h"
#include "src/errno/libc_errno.h"
#include "src/math/tanhf16.h"
#include "test/UnitTest/FPMatcher.h"
@@ -23,11 +24,11 @@ TEST_F(LlvmLibcTanhf16Test, SpecialNumbers) {
EXPECT_FP_EQ_WITH_EXCEPTION(aNaN, LIBC_NAMESPACE::tanhf16(sNaN), FE_INVALID);
EXPECT_MATH_ERRNO(0);
- EXPECT_FP_EQ_ALL_ROUNDING(static_cast<float16>(1.0),
+ EXPECT_FP_EQ_ALL_ROUNDING(LIBC_NAMESPACE::fputil::cast<float16>(1.0),
LIBC_NAMESPACE::tanhf16(inf));
EXPECT_MATH_ERRNO(0);
- EXPECT_FP_EQ_ALL_ROUNDING(static_cast<float16>(-1.0),
+ EXPECT_FP_EQ_ALL_ROUNDING(LIBC_NAMESPACE::fputil::cast<float16>(-1.0),
LIBC_NAMESPACE::tanhf16(neg_inf));
EXPECT_MATH_ERRNO(0);
@@ -41,91 +42,102 @@ TEST_F(LlvmLibcTanhf16Test, SpecialNumbers) {
TEST_F(LlvmLibcTanhf16Test, ResultNearBounds) {
LIBC_NAMESPACE::libc_errno = 0;
- EXPECT_FP_EQ_WITH_EXCEPTION(static_cast<float16>(1.0),
+ EXPECT_FP_EQ_WITH_EXCEPTION(LIBC_NAMESPACE::fputil::cast<float16>(1.0),
LIBC_NAMESPACE::tanhf16(max_normal), FE_INEXACT);
EXPECT_MATH_ERRNO(0);
- EXPECT_FP_EQ_WITH_EXCEPTION(static_cast<float16>(-1.0),
+ EXPECT_FP_EQ_WITH_EXCEPTION(LIBC_NAMESPACE::fputil::cast<float16>(-1.0),
LIBC_NAMESPACE::tanhf16(neg_max_normal),
FE_INEXACT);
EXPECT_MATH_ERRNO(0);
// round(atanh(1 - 2^-11), HP, RU);
- float16 x = static_cast<float16>(0x1.0a4p+2);
+ float16 x = LIBC_NAMESPACE::fputil::cast<float16>(0x1.0a4p+2);
EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_NEAREST(
- static_cast<float16>(0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ LIBC_NAMESPACE::fputil::cast<float16>(0x1.ffcp-1),
+ LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
EXPECT_MATH_ERRNO(0);
EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_UPWARD(
- static_cast<float16>(1.0), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ LIBC_NAMESPACE::fputil::cast<float16>(1.0), LIBC_NAMESPACE::tanhf16(x),
+ FE_INEXACT);
EXPECT_MATH_ERRNO(0);
EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_DOWNWARD(
- static_cast<float16>(0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ LIBC_NAMESPACE::fputil::cast<float16>(0x1.ffcp-1),
+ LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
EXPECT_MATH_ERRNO(0);
EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_TOWARD_ZERO(
- static_cast<float16>(0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ LIBC_NAMESPACE::fputil::cast<float16>(0x1.ffcp-1),
+ LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
EXPECT_MATH_ERRNO(0);
- x = static_cast<float16>(0x1.208p+2);
+ x = LIBC_NAMESPACE::fputil::cast<float16>(0x1.208p+2);
EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_NEAREST(
- static_cast<float16>(1.0), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ LIBC_NAMESPACE::fputil::cast<float16>(1.0), LIBC_NAMESPACE::tanhf16(x),
+ FE_INEXACT);
EXPECT_MATH_ERRNO(0);
EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_UPWARD(
- static_cast<float16>(1.0), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ LIBC_NAMESPACE::fputil::cast<float16>(1.0), LIBC_NAMESPACE::tanhf16(x),
+ FE_INEXACT);
EXPECT_MATH_ERRNO(0);
EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_DOWNWARD(
- static_cast<float16>(0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ LIBC_NAMESPACE::fputil::cast<float16>(0x1.ffcp-1),
+ LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
EXPECT_MATH_ERRNO(0);
EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_TOWARD_ZERO(
- static_cast<float16>(0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ LIBC_NAMESPACE::fputil::cast<float16>(0x1.ffcp-1),
+ LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
EXPECT_MATH_ERRNO(0);
// round(atanh(-1 + 2^-11), HP, RD);
- x = static_cast<float16>(-0x1.0a4p+2);
+ x = LIBC_NAMESPACE::fputil::cast<float16>(-0x1.0a4p+2);
EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_NEAREST(
- static_cast<float16>(-0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x),
- FE_INEXACT);
+ LIBC_NAMESPACE::fputil::cast<float16>(-0x1.ffcp-1),
+ LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
EXPECT_MATH_ERRNO(0);
- EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_UPWARD(static_cast<float16>(-0x1.ffcp-1),
- LIBC_NAMESPACE::tanhf16(x),
- FE_INEXACT);
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_UPWARD(
+ LIBC_NAMESPACE::fputil::cast<float16>(-0x1.ffcp-1),
+ LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
EXPECT_MATH_ERRNO(0);
EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_DOWNWARD(
- static_cast<float16>(-1.0), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ LIBC_NAMESPACE::fputil::cast<float16>(-1.0), LIBC_NAMESPACE::tanhf16(x),
+ FE_INEXACT);
EXPECT_MATH_ERRNO(0);
EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_TOWARD_ZERO(
- static_cast<float16>(-0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x),
- FE_INEXACT);
+ LIBC_NAMESPACE::fputil::cast<float16>(-0x1.ffcp-1),
+ LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
EXPECT_MATH_ERRNO(0);
- x = static_cast<float16>(-0x1.208p+2);
+ x = LIBC_NAMESPACE::fputil::cast<float16>(-0x1.208p+2);
EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_NEAREST(
- static_cast<float16>(-1.0), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ LIBC_NAMESPACE::fputil::cast<float16>(-1.0), LIBC_NAMESPACE::tanhf16(x),
+ FE_INEXACT);
EXPECT_MATH_ERRNO(0);
- EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_UPWARD(static_cast<float16>(-0x1.ffcp-1),
- LIBC_NAMESPACE::tanhf16(x),
- FE_INEXACT);
+ EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_UPWARD(
+ LIBC_NAMESPACE::fputil::cast<float16>(-0x1.ffcp-1),
+ LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
EXPECT_MATH_ERRNO(0);
EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_DOWNWARD(
- static_cast<float16>(-1.0), LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
+ LIBC_NAMESPACE::fputil::cast<float16>(-1.0), LIBC_NAMESPACE::tanhf16(x),
+ FE_INEXACT);
EXPECT_MATH_ERRNO(0);
EXPECT_FP_EQ_WITH_EXCEPTION_ROUNDING_TOWARD_ZERO(
- static_cast<float16>(-0x1.ffcp-1), LIBC_NAMESPACE::tanhf16(x),
- FE_INEXACT);
+ LIBC_NAMESPACE::fputil::cast<float16>(-0x1.ffcp-1),
+ LIBC_NAMESPACE::tanhf16(x), FE_INEXACT);
EXPECT_MATH_ERRNO(0);
}
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