[libc-commits] [libc] [libc][math][c23] Add asinhf16() function (PR #131351)
via libc-commits
libc-commits at lists.llvm.org
Fri Mar 14 09:25:57 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-libc
Author: Tejas Vipin (meltq)
<details>
<summary>Changes</summary>
Implement asinh for Float16 along with tests. Closes https://github.com/llvm/llvm-project/issues/131001
---
Full diff: https://github.com/llvm/llvm-project/pull/131351.diff
11 Files Affected:
- (modified) libc/config/linux/x86_64/entrypoints.txt (+1)
- (modified) libc/docs/headers/math/index.rst (+1-1)
- (modified) libc/include/math.yaml (+7)
- (modified) libc/src/math/CMakeLists.txt (+1)
- (added) libc/src/math/asinhf16.h (+21)
- (modified) libc/src/math/generic/CMakeLists.txt (+20)
- (added) libc/src/math/generic/asinhf16.cpp (+85)
- (modified) libc/test/src/math/CMakeLists.txt (+12)
- (added) libc/test/src/math/asinhf16_test.cpp (+42)
- (modified) libc/test/src/math/smoke/CMakeLists.txt (+12)
- (added) libc/test/src/math/smoke/asinhf16_test.cpp (+35)
``````````diff
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index a29478898fe70..85263a0dce24b 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -411,6 +411,7 @@ set(TARGET_LIBM_ENTRYPOINTS
libc.src.math.acoshf
libc.src.math.asinf
libc.src.math.asinhf
+ libc.src.math.asinhf16
libc.src.math.atan2
libc.src.math.atan2f
libc.src.math.atanf
diff --git a/libc/docs/headers/math/index.rst b/libc/docs/headers/math/index.rst
index 5b855ce4881c3..b3ac6a9732da7 100644
--- a/libc/docs/headers/math/index.rst
+++ b/libc/docs/headers/math/index.rst
@@ -257,7 +257,7 @@ Higher Math Functions
+-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
| asin | |check| | | | |check| | | 7.12.4.2 | F.10.1.2 |
+-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
-| asinh | |check| | | | | | 7.12.5.2 | F.10.2.2 |
+| asinh | |check| | | | |check| | | 7.12.5.2 | F.10.2.2 |
+-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
| asinpi | | | | | | 7.12.4.9 | F.10.1.9 |
+-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
diff --git a/libc/include/math.yaml b/libc/include/math.yaml
index a66f981030864..a124a1cf3e946 100644
--- a/libc/include/math.yaml
+++ b/libc/include/math.yaml
@@ -52,6 +52,13 @@ functions:
return_type: float
arguments:
- type: float
+ - name: asinhf16
+ standards:
+ - stdc
+ return_type: _Float16
+ arguments:
+ - type: _Float16
+ guard: LIBC_TYPES_HAS_FLOAT16
- name: atan2
standards:
- stdc
diff --git a/libc/src/math/CMakeLists.txt b/libc/src/math/CMakeLists.txt
index f18a73d46f9aa..fe6d0d520e207 100644
--- a/libc/src/math/CMakeLists.txt
+++ b/libc/src/math/CMakeLists.txt
@@ -53,6 +53,7 @@ add_math_entrypoint_object(asinf16)
add_math_entrypoint_object(asinh)
add_math_entrypoint_object(asinhf)
+add_math_entrypoint_object(asinhf16)
add_math_entrypoint_object(atan)
add_math_entrypoint_object(atanf)
diff --git a/libc/src/math/asinhf16.h b/libc/src/math/asinhf16.h
new file mode 100644
index 0000000000000..2969a3498164f
--- /dev/null
+++ b/libc/src/math/asinhf16.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for asinhf16 -----------------------*- 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_ASINHF16_H
+#define LLVM_LIBC_SRC_MATH_ASINHF16_H
+
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+float16 asinhf16(float16 x);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_MATH_ASINHF16_H
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
index 3114289bad486..3b982af2b7a2d 100644
--- a/libc/src/math/generic/CMakeLists.txt
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -3959,6 +3959,26 @@ add_entrypoint_object(
libc.src.__support.macros.optimization
)
+add_entrypoint_object(
+ asinhf16
+ SRCS
+ asinhf16.cpp
+ HDRS
+ ../asinhf16.h
+ DEPENDS
+ .explogxf
+ libc.hdr.fenv_macros
+ libc.src.__support.FPUtil.cast
+ libc.src.__support.FPUtil.fenv_impl
+ libc.src.__support.FPUtil.fp_bits
+ libc.src.__support.FPUtil.fp_bits
+ libc.src.__support.FPUtil.multiply_add
+ libc.src.__support.FPUtil.polyeval
+ libc.src.__support.FPUtil.sqrt
+ libc.src.__support.macros.optimization
+ libc.src.__support.macros.properties.types
+)
+
add_entrypoint_object(
atanhf
SRCS
diff --git a/libc/src/math/generic/asinhf16.cpp b/libc/src/math/generic/asinhf16.cpp
new file mode 100644
index 0000000000000..d8a6058623514
--- /dev/null
+++ b/libc/src/math/generic/asinhf16.cpp
@@ -0,0 +1,85 @@
+//===-- Half-precision asinhf16(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/asinhf16.h"
+#include "src/math/generic/explogxf.h"
+#include "src/__support/FPUtil/except_value_utils.h"
+#include "src/__support/FPUtil/generic/sqrt.h"
+#include "src/__support/FPUtil/multiply_add.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+#ifndef LIBC_MATH_HAS_SKIP_ACCURATE_PASS
+static constexpr size_t N_EXCEPTS = 8;
+
+static constexpr fputil::ExceptValues<float16, N_EXCEPTS> ASINHF16_EXCEPTS{{
+ // (input, RZ output, RU offset, RD offset, RN offset)
+ {0x3769, 0x372A, 1, 0, 1},
+ {0x3B5B, 0x3A96, 1, 0, 0},
+ {0x4B1F, 0x42B3, 1, 0, 0},
+ {0x4C9B, 0x4336, 1, 0, 1},
+ {0xB769, 0xB72A, 0, 1, 1},
+ {0xBB5B, 0xBA96, 0, 1, 0},
+ {0xCB1F, 0xC2B3, 0, 1, 0},
+ {0xCC9B, 0xC336, 0, 1, 1}
+}};
+#endif // !LIBC_MATH_HAS_SKIP_ACCURATE_PASS
+
+LLVM_LIBC_FUNCTION(float16, asinhf16, (float16 x)) {
+ using FPBits = fputil::FPBits<float16>;
+ FPBits xbits(x);
+
+ float x_d = x;
+ uint16_t x_u = xbits.uintval();
+ uint16_t x_abs = x_u & 0x7fff;
+
+ if (LIBC_UNLIKELY(xbits.is_inf_or_nan())) {
+ if (xbits.is_signaling_nan()) {
+ fputil::raise_except_if_required(FE_INVALID);
+ return FPBits::quiet_nan().get_val();
+ }
+
+ return x;
+ }
+
+#ifndef LIBC_MATH_HAS_SKIP_ACCURATE_PASS
+ // Handle exceptional values
+ if (auto r = ASINHF16_EXCEPTS.lookup(x_u); LIBC_UNLIKELY(r.has_value()))
+ return r.value();
+#endif // !LIBC_MATH_HAS_SKIP_ACCURATE_PASS
+
+ const float SIGN[2] = {1.0f, -1.0f};
+ float x_sign = SIGN[x_u >> 15];
+
+ // |x| <= 0.25
+ if (LIBC_UNLIKELY(x_abs <= 0x3400)) {
+ if (LIBC_UNLIKELY(x_abs == 0))
+ return x;
+ if (LIBC_UNLIKELY((fputil::get_round() == FE_UPWARD) &&
+ (x_u >= 0x8401) && (x_u <= 0x90E6)))
+ return static_cast<float16>(x_d + 0x1p-24f);
+
+ float x_sq = x_d * x_d;
+ // Generated by Sollya with:
+ // > P = fpminimax(asinh(x)/x, [|0, 2, 4, 6, 8|], [|SG...|],[0, 2^-2]);
+ float p = fputil::polyeval(x_sq, 1.0f, -0x1.555556p-3f, 0x1.3334dep-4f,
+ -0x1.6f3e2p-5f, 0x1.51d012p-5f);
+
+ return static_cast<float16>(fputil::multiply_add(x_d, p, 0.0f));
+ }
+
+ // General case: asinh(x) = ln(x + sqrt(x^2 + 1))
+ float sqrt_term = fputil::sqrt<float>(fputil::multiply_add(x_d, x_d, 1.0f));
+ return fputil::cast<float16>(x_sign * log_eval(
+ fputil::multiply_add(x_d, x_sign, sqrt_term)));
+}
+}
diff --git a/libc/test/src/math/CMakeLists.txt b/libc/test/src/math/CMakeLists.txt
index 53ddd301900c0..01b802ff4c943 100644
--- a/libc/test/src/math/CMakeLists.txt
+++ b/libc/test/src/math/CMakeLists.txt
@@ -2160,6 +2160,18 @@ add_fp_unittest(
libc.src.__support.FPUtil.fp_bits
)
+
+add_fp_unittest(
+ asinhf16_test
+ NEED_MPFR
+ SUITE
+ libc-math-unittests
+ SRCS
+ asinhf16_test.cpp
+ DEPENDS
+ libc.src.math.asinhf16
+)
+
add_fp_unittest(
acoshf_test
NEED_MPFR
diff --git a/libc/test/src/math/asinhf16_test.cpp b/libc/test/src/math/asinhf16_test.cpp
new file mode 100644
index 0000000000000..32f3aa141d685
--- /dev/null
+++ b/libc/test/src/math/asinhf16_test.cpp
@@ -0,0 +1,42 @@
+//===-- Exhaustive test for asinhf16 ---------------------------------------===//
+//
+// 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/asinhf16.h"
+#include "test/UnitTest/FPMatcher.h"
+#include "test/UnitTest/Test.h"
+#include "utils/MPFRWrapper/MPFRUtils.h"
+
+using LlvmLibcAsinhf16Test = 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(LlvmLibcAsinhf16Test, PositiveRange) {
+ for (uint16_t v = POS_START; v <= POS_STOP; ++v) {
+ float16 x = FPBits(v).get_val();
+
+ EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Asinh, x,
+ LIBC_NAMESPACE::asinhf16(x), 0.5);
+ }
+}
+
+TEST_F(LlvmLibcAsinhf16Test, NegativeRange) {
+ for (uint16_t v = NEG_START; v <= NEG_STOP; ++v) {
+ float16 x = FPBits(v).get_val();
+
+ EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Asinh, x,
+ LIBC_NAMESPACE::asinhf16(x), 0.5);
+ }
+}
diff --git a/libc/test/src/math/smoke/CMakeLists.txt b/libc/test/src/math/smoke/CMakeLists.txt
index 6f94440d826d9..bb304f0beff1f 100644
--- a/libc/test/src/math/smoke/CMakeLists.txt
+++ b/libc/test/src/math/smoke/CMakeLists.txt
@@ -3933,6 +3933,18 @@ add_fp_unittest(
libc.src.__support.FPUtil.fp_bits
)
+add_fp_unittest(
+ asinhf16_test
+ SUITE
+ libc-math-smoke-tests
+ SRCS
+ asinhf16_test.cpp
+ DEPENDS
+ libc.src.errno.errno
+ libc.src.math.asinhf16
+ libc.src.__support.FPUtil.fp_bits
+)
+
add_fp_unittest(
acoshf_test
SUITE
diff --git a/libc/test/src/math/smoke/asinhf16_test.cpp b/libc/test/src/math/smoke/asinhf16_test.cpp
new file mode 100644
index 0000000000000..6faac38067ca8
--- /dev/null
+++ b/libc/test/src/math/smoke/asinhf16_test.cpp
@@ -0,0 +1,35 @@
+//===-- Unittests for asinhf16 ----------------------------------------------===//
+//
+// 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/errno/libc_errno.h"
+#include "src/math/asinhf16.h"
+#include "test/UnitTest/FPMatcher.h"
+#include "test/UnitTest/Test.h"
+
+using LlvmLibcAsinhf16Test = LIBC_NAMESPACE::testing::FPTest<float16>;
+
+TEST_F(LlvmLibcAsinhf16Test, SpecialNumbers) {
+ LIBC_NAMESPACE::libc_errno = 0;
+ EXPECT_FP_EQ(aNaN, LIBC_NAMESPACE::asinhf16(aNaN));
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ_WITH_EXCEPTION(aNaN, LIBC_NAMESPACE::asinhf16(sNaN), FE_INVALID);
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ(0.0f, LIBC_NAMESPACE::asinhf16(0.0f));
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ(-0.0f, LIBC_NAMESPACE::asinhf16(-0.0f));
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ(inf, LIBC_NAMESPACE::asinhf16(inf));
+ EXPECT_MATH_ERRNO(0);
+
+ EXPECT_FP_EQ(neg_inf, LIBC_NAMESPACE::asinhf16(neg_inf));
+ EXPECT_MATH_ERRNO(0);
+}
``````````
</details>
https://github.com/llvm/llvm-project/pull/131351
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