[libc] [llvm] [libc][math] Refactor hypotf16 to Header Only. (PR #180511)
via llvm-commits
llvm-commits at lists.llvm.org
Fri Feb 13 22:13:26 PST 2026
https://github.com/Sukumarsawant updated https://github.com/llvm/llvm-project/pull/180511
>From 6628fecb7488f683275f893e5bb312961dc44d66 Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Mon, 9 Feb 2026 14:14:02 +0530
Subject: [PATCH 1/3] intial commit
---
libc/shared/math.h | 1 +
libc/shared/math/hypotf16.h | 31 +++++
libc/src/__support/math/CMakeLists.txt | 15 +++
libc/src/__support/math/hypotf16.h | 97 +++++++++++++++
libc/src/math/generic/CMakeLists.txt | 9 +-
libc/src/math/generic/hypotf16.cpp | 111 ++++--------------
libc/test/shared/CMakeLists.txt | 1 +
libc/test/shared/shared_math_test.cpp | 1 +
.../llvm-project-overlay/libc/BUILD.bazel | 21 +++-
9 files changed, 187 insertions(+), 100 deletions(-)
create mode 100644 libc/shared/math/hypotf16.h
create mode 100644 libc/src/__support/math/hypotf16.h
diff --git a/libc/shared/math.h b/libc/shared/math.h
index 66132326c2257..74051f4b7240a 100644
--- a/libc/shared/math.h
+++ b/libc/shared/math.h
@@ -73,6 +73,7 @@
#include "math/fsqrtf128.h"
#include "math/fsqrtl.h"
#include "math/hypotf.h"
+#include "math/hypotf16.h"
#include "math/ilogb.h"
#include "math/ilogbf.h"
#include "math/ilogbf128.h"
diff --git a/libc/shared/math/hypotf16.h b/libc/shared/math/hypotf16.h
new file mode 100644
index 0000000000000..ebb83e3450fcd
--- /dev/null
+++ b/libc/shared/math/hypotf16.h
@@ -0,0 +1,31 @@
+//===-- Shared hypotf16 function --------------------------------*- 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_SHARED_MATH_HYPOTF16_H
+#define LLVM_LIBC_SHARED_MATH_HYPOTF16_H
+
+#include "include/llvm-libc-macros/float16-macros.h"
+#include "shared/libc_common.h"
+
+#ifdef LIBC_TYPES_HAS_FLOAT16
+
+#include "src/__support/math/hypotf16.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+namespace shared {
+
+using math::hypotf16;
+
+} // namespace shared
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LIBC_TYPES_HAS_FLOAT16
+
+#endif // LLVM_LIBC_SHARED_MATH_HYPOTF16_H
diff --git a/libc/src/__support/math/CMakeLists.txt b/libc/src/__support/math/CMakeLists.txt
index c0293c0969217..bc701954f1309 100644
--- a/libc/src/__support/math/CMakeLists.txt
+++ b/libc/src/__support/math/CMakeLists.txt
@@ -1124,6 +1124,21 @@ add_header_library(
libc.src.__support.macros.optimization
)
+add_header_library(
+ hypotf16
+ HDRS
+ hypotf16.h
+ DEPENDS
+ libc.src.__support.FPUtil.fenv_impl
+ libc.src.__support.FPUtil.fp_bits
+ libc.src.__support.FPUtil.cast
+ libc.src.__support.FPUtil.multiply_add
+ libc.src.__support.FPUtil.sqrt
+ libc.src.__support.macros.optimization
+ libc.src.__support.macros.properties.types
+ libc.include.llvm-libc-macros.float16_macros
+)
+
add_header_library(
ilogbl
HDRS
diff --git a/libc/src/__support/math/hypotf16.h b/libc/src/__support/math/hypotf16.h
new file mode 100644
index 0000000000000..3efa70850ec18
--- /dev/null
+++ b/libc/src/__support/math/hypotf16.h
@@ -0,0 +1,97 @@
+//===-- Implementation header for hypotf16 ----------------------*- 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___SUPPORT_MATH_HYPOTF16_H
+#define LLVM_LIBC_SRC___SUPPORT_MATH_HYPOTF16_H
+
+#include "src/__support/FPUtil/FEnvImpl.h"
+#include "src/__support/FPUtil/FPBits.h"
+#include "src/__support/FPUtil/cast.h"
+#include "src/__support/FPUtil/multiply_add.h"
+#include "src/__support/FPUtil/sqrt.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/optimization.h"
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+namespace math {
+
+LIBC_INLINE float16 hypotf16(float16 x, float16 y) {
+ using FloatBits = fputil::FPBits<float>;
+ using FPBits = fputil::FPBits<float16>;
+
+ FPBits x_abs = FPBits(x).abs();
+ FPBits y_abs = FPBits(y).abs();
+
+ bool x_abs_larger = x_abs.uintval() >= y_abs.uintval();
+
+ FPBits a_bits = x_abs_larger ? x_abs : y_abs;
+ FPBits b_bits = x_abs_larger ? y_abs : x_abs;
+
+ uint16_t a_u = a_bits.uintval();
+ uint16_t b_u = b_bits.uintval();
+
+ // Note: replacing `a_u >= FPBits::EXP_MASK` with `a_bits.is_inf_or_nan()`
+ // generates extra exponent bit masking instructions on x86-64.
+ if (LIBC_UNLIKELY(a_u >= FPBits::EXP_MASK)) {
+ // x or y is inf or nan
+ if (a_bits.is_signaling_nan() || b_bits.is_signaling_nan()) {
+ fputil::raise_except_if_required(FE_INVALID);
+ return FPBits::quiet_nan().get_val();
+ }
+ if (a_bits.is_inf() || b_bits.is_inf())
+ return FPBits::inf().get_val();
+ return a_bits.get_val();
+ }
+
+ float af = fputil::cast<float>(a_bits.get_val());
+ float bf = fputil::cast<float>(b_bits.get_val());
+
+ // Compiler runtime basic operations for float16 might not be correctly
+ // rounded for all rounding modes.
+ if (LIBC_UNLIKELY(a_u - b_u >=
+ static_cast<uint16_t>((FPBits::FRACTION_LEN + 2)
+ << FPBits::FRACTION_LEN)))
+ return fputil::cast<float16>(af + bf);
+
+ // These squares are exact.
+ float a_sq = af * af;
+ float sum_sq = fputil::multiply_add(bf, bf, a_sq);
+
+ FloatBits result(fputil::sqrt<float>(sum_sq));
+ uint32_t r_u = result.uintval();
+
+ // If any of the sticky bits of the result are non-zero, except the LSB, then
+ // the rounded result is correct.
+ if (LIBC_UNLIKELY(((r_u + 1) & 0x0000'0FFE) == 0)) {
+ float r_d = result.get_val();
+
+ // Perform rounding correction.
+ float sum_sq_lo = fputil::multiply_add(bf, bf, a_sq - sum_sq);
+ float err = sum_sq_lo - fputil::multiply_add(r_d, r_d, -sum_sq);
+
+ if (err > 0) {
+ r_u |= 1;
+ } else if ((err < 0) && (r_u & 1) == 0) {
+ r_u -= 1;
+ } else if ((r_u & 0x0000'1FFF) == 0) {
+ // The rounded result is exact.
+ fputil::clear_except_if_required(FE_INEXACT);
+ }
+ return fputil::cast<float16>(FloatBits(r_u).get_val());
+ }
+
+ return fputil::cast<float16>(result.get_val());
+}
+
+} // namespace math
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_MATH_HYPOTF16_H
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
index 96dc0e7ca4851..9eda20e1e41b2 100644
--- a/libc/src/math/generic/CMakeLists.txt
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -3180,13 +3180,8 @@ add_entrypoint_object(
HDRS
../hypotf16.h
DEPENDS
- libc.src.__support.FPUtil.fenv_impl
- libc.src.__support.FPUtil.fp_bits
- libc.src.__support.FPUtil.cast
- libc.src.__support.FPUtil.multiply_add
- libc.src.__support.FPUtil.sqrt
- libc.src.__support.macros.optimization
- libc.src.__support.macros.properties.types
+ libc.src.__support.math.hypotf16
+ libc.src.errno.errno
)
add_entrypoint_object(
diff --git a/libc/src/math/generic/hypotf16.cpp b/libc/src/math/generic/hypotf16.cpp
index fa90069f9ff0d..8d02849b23d1c 100644
--- a/libc/src/math/generic/hypotf16.cpp
+++ b/libc/src/math/generic/hypotf16.cpp
@@ -1,91 +1,20 @@
-//===-- Implementation of hypotf16 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/hypotf16.h"
-#include "src/__support/FPUtil/FEnvImpl.h"
-#include "src/__support/FPUtil/FPBits.h"
-#include "src/__support/FPUtil/cast.h"
-#include "src/__support/FPUtil/multiply_add.h"
-#include "src/__support/FPUtil/sqrt.h"
-#include "src/__support/common.h"
-#include "src/__support/macros/optimization.h"
-#include "src/__support/macros/properties/types.h"
-
-namespace LIBC_NAMESPACE_DECL {
-
-// For targets where conversion from float to float16 has to be
-// emulated, fputil::hypot<float16> is faster
-LLVM_LIBC_FUNCTION(float16, hypotf16, (float16 x, float16 y)) {
- using FloatBits = fputil::FPBits<float>;
- using FPBits = fputil::FPBits<float16>;
-
- FPBits x_abs = FPBits(x).abs();
- FPBits y_abs = FPBits(y).abs();
-
- bool x_abs_larger = x_abs.uintval() >= y_abs.uintval();
-
- FPBits a_bits = x_abs_larger ? x_abs : y_abs;
- FPBits b_bits = x_abs_larger ? y_abs : x_abs;
-
- uint16_t a_u = a_bits.uintval();
- uint16_t b_u = b_bits.uintval();
-
- // Note: replacing `a_u >= FPBits::EXP_MASK` with `a_bits.is_inf_or_nan()`
- // generates extra exponent bit masking instructions on x86-64.
- if (LIBC_UNLIKELY(a_u >= FPBits::EXP_MASK)) {
- // x or y is inf or nan
- if (a_bits.is_signaling_nan() || b_bits.is_signaling_nan()) {
- fputil::raise_except_if_required(FE_INVALID);
- return FPBits::quiet_nan().get_val();
- }
- if (a_bits.is_inf() || b_bits.is_inf())
- return FPBits::inf().get_val();
- return a_bits.get_val();
- }
-
- float af = fputil::cast<float>(a_bits.get_val());
- float bf = fputil::cast<float>(b_bits.get_val());
-
- // Compiler runtime basic operations for float16 might not be correctly
- // rounded for all rounding modes.
- if (LIBC_UNLIKELY(a_u - b_u >=
- static_cast<uint16_t>((FPBits::FRACTION_LEN + 2)
- << FPBits::FRACTION_LEN)))
- return fputil::cast<float16>(af + bf);
-
- // These squares are exact.
- float a_sq = af * af;
- float sum_sq = fputil::multiply_add(bf, bf, a_sq);
-
- FloatBits result(fputil::sqrt<float>(sum_sq));
- uint32_t r_u = result.uintval();
-
- // If any of the sticky bits of the result are non-zero, except the LSB, then
- // the rounded result is correct.
- if (LIBC_UNLIKELY(((r_u + 1) & 0x0000'0FFE) == 0)) {
- float r_d = result.get_val();
-
- // Perform rounding correction.
- float sum_sq_lo = fputil::multiply_add(bf, bf, a_sq - sum_sq);
- float err = sum_sq_lo - fputil::multiply_add(r_d, r_d, -sum_sq);
-
- if (err > 0) {
- r_u |= 1;
- } else if ((err < 0) && (r_u & 1) == 0) {
- r_u -= 1;
- } else if ((r_u & 0x0000'1FFF) == 0) {
- // The rounded result is exact.
- fputil::clear_except_if_required(FE_INEXACT);
- }
- return fputil::cast<float16>(FloatBits(r_u).get_val());
- }
-
- return fputil::cast<float16>(result.get_val());
-}
-
-} // namespace LIBC_NAMESPACE_DECL
+//===-- Implementation of hypotf16 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/hypotf16.h"
+#include "src/__support/math/hypotf16.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+// For targets where conversion from float to float16 has to be
+// emulated, fputil::hypot<float16> is faster
+LLVM_LIBC_FUNCTION(float16, hypotf16, (float16 x, float16 y)) {
+ return math::hypotf16(x, y);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/test/shared/CMakeLists.txt b/libc/test/shared/CMakeLists.txt
index 7d72ced3e057c..12053fa4a68ac 100644
--- a/libc/test/shared/CMakeLists.txt
+++ b/libc/test/shared/CMakeLists.txt
@@ -69,6 +69,7 @@ add_fp_unittest(
libc.src.__support.math.fsqrtf128
libc.src.__support.math.fsqrtl
libc.src.__support.math.hypotf
+ libc.src.__support.math.hypotf16
libc.src.__support.math.ilogb
libc.src.__support.math.ilogbf
libc.src.__support.math.ilogbf16
diff --git a/libc/test/shared/shared_math_test.cpp b/libc/test/shared/shared_math_test.cpp
index 9e024387efbfa..f5594f511eb27 100644
--- a/libc/test/shared/shared_math_test.cpp
+++ b/libc/test/shared/shared_math_test.cpp
@@ -33,6 +33,7 @@ TEST(LlvmLibcSharedMathTest, AllFloat16) {
EXPECT_FP_EQ(0x0p+0f16, LIBC_NAMESPACE::shared::exp2m1f16(0.0f16));
EXPECT_FP_EQ(0x1p+0f16, LIBC_NAMESPACE::shared::expf16(0.0f16));
EXPECT_FP_EQ(0x0p+0f16, LIBC_NAMESPACE::shared::expm1f16(0.0f16));
+ EXPECT_FP_EQ(0x0p+0f16, LIBC_NAMESPACE::shared::hypotf16(0.0f16,0.0f16));
EXPECT_FP_EQ(0x0p+0f16, LIBC_NAMESPACE::shared::logf16(1.0f16));
EXPECT_FP_EQ(0x0p+0f16, LIBC_NAMESPACE::shared::sinhf16(0.0f16));
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index ae7228c52d3c0..906534548c63c 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -3742,6 +3742,23 @@ libc_support_library(
],
)
+libc_support_library(
+ name = "__support_math_hypotf16",
+ hdrs = ["src/__support/math/hypotf16.h"],
+ deps = [
+ ":__support_common",
+ ":__support_fputil_cast",
+ ":__support_fputil_fenv_impl",
+ ":__support_fputil_fp_bits",
+ ":__support_fputil_multiply_add",
+ ":__support_fputil_sqrt",
+ ":__support_macros_config",
+ ":__support_macros_optimization",
+ ":__support_macros_properties_types",
+ ":llvm_libc_macros_float16_macros",
+ ],
+)
+
libc_support_library(
name = "__support_math_sinhf",
hdrs = ["src/__support/math/sinhf.h"],
@@ -4885,8 +4902,8 @@ libc_math_function(
libc_math_function(
name = "hypotf16",
additional_deps = [
- ":__support_fputil_multiply_add",
- ":__support_fputil_sqrt",
+ ":__support_math_hypotf16",
+ ":errno",
],
)
>From 9776762be56b4cf3388a237b3a7b4852dddabaf5 Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Mon, 9 Feb 2026 18:01:45 +0530
Subject: [PATCH 2/3] crlf to lf cpp file + formatted + tested
---
libc/src/math/generic/hypotf16.cpp | 40 +++++++++++++--------------
libc/test/shared/shared_math_test.cpp | 2 +-
2 files changed, 21 insertions(+), 21 deletions(-)
diff --git a/libc/src/math/generic/hypotf16.cpp b/libc/src/math/generic/hypotf16.cpp
index 8d02849b23d1c..6bd76eab22a74 100644
--- a/libc/src/math/generic/hypotf16.cpp
+++ b/libc/src/math/generic/hypotf16.cpp
@@ -1,20 +1,20 @@
-//===-- Implementation of hypotf16 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/hypotf16.h"
-#include "src/__support/math/hypotf16.h"
-
-namespace LIBC_NAMESPACE_DECL {
-
-// For targets where conversion from float to float16 has to be
-// emulated, fputil::hypot<float16> is faster
-LLVM_LIBC_FUNCTION(float16, hypotf16, (float16 x, float16 y)) {
- return math::hypotf16(x, y);
-}
-
-} // namespace LIBC_NAMESPACE_DECL
+//===-- Implementation of hypotf16 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/hypotf16.h"
+#include "src/__support/math/hypotf16.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+// For targets where conversion from float to float16 has to be
+// emulated, fputil::hypot<float16> is faster
+LLVM_LIBC_FUNCTION(float16, hypotf16, (float16 x, float16 y)) {
+ return math::hypotf16(x, y);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/test/shared/shared_math_test.cpp b/libc/test/shared/shared_math_test.cpp
index f5594f511eb27..2977112f21adc 100644
--- a/libc/test/shared/shared_math_test.cpp
+++ b/libc/test/shared/shared_math_test.cpp
@@ -33,7 +33,7 @@ TEST(LlvmLibcSharedMathTest, AllFloat16) {
EXPECT_FP_EQ(0x0p+0f16, LIBC_NAMESPACE::shared::exp2m1f16(0.0f16));
EXPECT_FP_EQ(0x1p+0f16, LIBC_NAMESPACE::shared::expf16(0.0f16));
EXPECT_FP_EQ(0x0p+0f16, LIBC_NAMESPACE::shared::expm1f16(0.0f16));
- EXPECT_FP_EQ(0x0p+0f16, LIBC_NAMESPACE::shared::hypotf16(0.0f16,0.0f16));
+ EXPECT_FP_EQ(0x0p+0f16, LIBC_NAMESPACE::shared::hypotf16(0.0f16, 0.0f16));
EXPECT_FP_EQ(0x0p+0f16, LIBC_NAMESPACE::shared::logf16(1.0f16));
EXPECT_FP_EQ(0x0p+0f16, LIBC_NAMESPACE::shared::sinhf16(0.0f16));
>From 12729476cfaae22b54a817f90e5a0be427d36898 Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Sat, 14 Feb 2026 11:37:42 +0530
Subject: [PATCH 3/3] FIX : removed errno and moved comment
---
libc/src/__support/math/hypotf16.h | 2 ++
libc/src/math/generic/CMakeLists.txt | 1 -
libc/src/math/generic/hypotf16.cpp | 2 --
utils/bazel/llvm-project-overlay/libc/BUILD.bazel | 1 -
4 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/libc/src/__support/math/hypotf16.h b/libc/src/__support/math/hypotf16.h
index 3efa70850ec18..07e8a0566b8ec 100644
--- a/libc/src/__support/math/hypotf16.h
+++ b/libc/src/__support/math/hypotf16.h
@@ -22,6 +22,8 @@ namespace LIBC_NAMESPACE_DECL {
namespace math {
+// For targets where conversion from float to float16 has to be
+// emulated, fputil::hypot<float16> is faster
LIBC_INLINE float16 hypotf16(float16 x, float16 y) {
using FloatBits = fputil::FPBits<float>;
using FPBits = fputil::FPBits<float16>;
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
index 9eda20e1e41b2..1565172d92103 100644
--- a/libc/src/math/generic/CMakeLists.txt
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -3181,7 +3181,6 @@ add_entrypoint_object(
../hypotf16.h
DEPENDS
libc.src.__support.math.hypotf16
- libc.src.errno.errno
)
add_entrypoint_object(
diff --git a/libc/src/math/generic/hypotf16.cpp b/libc/src/math/generic/hypotf16.cpp
index 6bd76eab22a74..749d4eedd1416 100644
--- a/libc/src/math/generic/hypotf16.cpp
+++ b/libc/src/math/generic/hypotf16.cpp
@@ -11,8 +11,6 @@
namespace LIBC_NAMESPACE_DECL {
-// For targets where conversion from float to float16 has to be
-// emulated, fputil::hypot<float16> is faster
LLVM_LIBC_FUNCTION(float16, hypotf16, (float16 x, float16 y)) {
return math::hypotf16(x, y);
}
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index 906534548c63c..a28f3e7c9ea4e 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -4903,7 +4903,6 @@ libc_math_function(
name = "hypotf16",
additional_deps = [
":__support_math_hypotf16",
- ":errno",
],
)
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