[libc] [math] Refactor fsqrtl to be header-only by Atharva062006 · Pull Request #176169 · llvm/llvm-project

Atharva062006 · 2026-01-15T14:00:16Z

This PR refactors fsqrtl to be header only as discussed. No functional change intended. Test and build files were updated as required by the refactor
Fixes #175335

github-actions · 2026-01-15T14:00:36Z

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llvmbot · 2026-01-15T14:01:23Z

@llvm/pr-subscribers-libc

Author: Atharv Mane (Atharva062006)

Changes

This PR refactors fsqrtl to be header only as discussed. No functional change intended. Test and build files were updated as required by the refactor

Full diff: https://github.com/llvm/llvm-project/pull/176169.diff

9 Files Affected:

(modified) libc/shared/math.h (+1)
(added) libc/shared/math/fsqrtl.h (+24)
(modified) libc/src/__support/math/CMakeLists.txt (+8)
(added) libc/src/__support/math/fsqrtl.h (+26)
(modified) libc/src/math/generic/CMakeLists.txt (+1-1)
(modified) libc/src/math/generic/fsqrtl.cpp (+2-3)
(modified) libc/test/shared/CMakeLists.txt (+1)
(modified) libc/test/shared/shared_math_test.cpp (+1)
(modified) utils/bazel/llvm-project-overlay/libc/BUILD.bazel (+9-1)

diff --git a/libc/shared/math.h b/libc/shared/math.h
index 287f3aea1565a..8fe5f82da696b 100644
--- a/libc/shared/math.h
+++ b/libc/shared/math.h
@@ -60,6 +60,7 @@
 #include "math/frexpf.h"
 #include "math/frexpf128.h"
 #include "math/frexpf16.h"
+#include "math/fsqrtl.h"
 #include "math/ilogbf16.h"
 #include "math/ldexpf.h"
 #include "math/ldexpf128.h"
diff --git a/libc/shared/math/fsqrtl.h b/libc/shared/math/fsqrtl.h
new file mode 100644
index 0000000000000..9e99c229431ae
--- /dev/null
+++ b/libc/shared/math/fsqrtl.h
@@ -0,0 +1,24 @@
+//===-- Shared header for fsqrtl ---------------------------------*- 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_FSQRTL_H
+#define LLVM_LIBC_SHARED_MATH_FSQRTL_H
+
+#include "shared/libc_common.h"
+#include "src/__support/math/fsqrtl.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+namespace shared {
+
+using math::fsqrtl;
+
+} // namespace shared
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SHARED_MATH_FSQRTL_H
\ No newline at end of file
diff --git a/libc/src/__support/math/CMakeLists.txt b/libc/src/__support/math/CMakeLists.txt
index 4139a1b1d3444..005ad69b487d5 100644
--- a/libc/src/__support/math/CMakeLists.txt
+++ b/libc/src/__support/math/CMakeLists.txt
@@ -1078,3 +1078,11 @@ add_header_library(
     libc.src.__support.math.sincos_eval
     libc.src.__support.macros.optimization
 )
+
+add_header_library(
+  fsqrtl
+  HDRS
+    fsqrtl.h
+  DEPENDS
+    libc.src.__support.FPUtil.generic.sqrt
+)
diff --git a/libc/src/__support/math/fsqrtl.h b/libc/src/__support/math/fsqrtl.h
new file mode 100644
index 0000000000000..5a21ea6c9d25c
--- /dev/null
+++ b/libc/src/__support/math/fsqrtl.h
@@ -0,0 +1,26 @@
+//===-- Implementation header for fsqrtl ------------------------*- 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_FSQRTL_H
+#define LLVM_LIBC_SRC___SUPPORT_MATH_FSQRTL_H
+
+#include "src/__support/FPUtil/generic/sqrt.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+namespace math {
+
+LIBC_INLINE static constexpr float fsqrt(long double x) {
+  return fputil::sqrt<float>(x);
+}
+
+} // namespace math
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_MATH_FSQRTL_H
\ No newline at end of file
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
index 6de4cf376bf02..895bf77b12ee5 100644
--- a/libc/src/math/generic/CMakeLists.txt
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -5234,7 +5234,7 @@ add_entrypoint_object(
   HDRS
     ../fsqrtl.h
   DEPENDS
-    libc.src.__support.FPUtil.generic.sqrt
+    libc.src.__support.math.fsqrtl
 )
 
 add_entrypoint_object(
diff --git a/libc/src/math/generic/fsqrtl.cpp b/libc/src/math/generic/fsqrtl.cpp
index b896a84aeded8..9deb86b558ea7 100644
--- a/libc/src/math/generic/fsqrtl.cpp
+++ b/libc/src/math/generic/fsqrtl.cpp
@@ -10,11 +10,10 @@
 #include "src/__support/FPUtil/generic/sqrt.h"
 #include "src/__support/common.h"
 #include "src/__support/macros/config.h"
+#include "src/__support/math/fsqrtl.h"
 
 namespace LIBC_NAMESPACE_DECL {
 
-LLVM_LIBC_FUNCTION(float, fsqrtl, (long double x)) {
-  return fputil::sqrt<float>(x);
-}
+LLVM_LIBC_FUNCTION(float, fsqrtl, (long double x)) { return math::fsqrtl(x); }
 
 } // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/test/shared/CMakeLists.txt b/libc/test/shared/CMakeLists.txt
index c5955ecfd54cb..ab74a1fff22a6 100644
--- a/libc/test/shared/CMakeLists.txt
+++ b/libc/test/shared/CMakeLists.txt
@@ -56,6 +56,7 @@ add_fp_unittest(
     libc.src.__support.math.frexpf
     libc.src.__support.math.frexpf128
     libc.src.__support.math.frexpf16
+    libc.src.__support.math.fsqrtl
     libc.src.__support.math.ilogbf16
     libc.src.__support.math.log
     libc.src.__support.math.ldexpf
diff --git a/libc/test/shared/shared_math_test.cpp b/libc/test/shared/shared_math_test.cpp
index 20a98a1a9138c..d1480977dda19 100644
--- a/libc/test/shared/shared_math_test.cpp
+++ b/libc/test/shared/shared_math_test.cpp
@@ -92,6 +92,7 @@ TEST(LlvmLibcSharedMathTest, AllDouble) {
   EXPECT_FP_EQ(0x1p+0, LIBC_NAMESPACE::shared::exp2(0.0));
   EXPECT_FP_EQ(0x1p+0, LIBC_NAMESPACE::shared::exp10(0.0));
   EXPECT_FP_EQ(0x0p+0, LIBC_NAMESPACE::shared::expm1(0.0));
+  EXPECT_FP_EQ(0x0p+0, LIBC_NAMESPACE::shared::fsqrtl(0.0));
   EXPECT_FP_EQ(0x0p+0, LIBC_NAMESPACE::shared::log(1.0));
   EXPECT_FP_EQ(0.0, LIBC_NAMESPACE::shared::sin(0.0));
 }
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index c03c21b834895..cf2ad3bdcb039 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -2813,6 +2813,14 @@ libc_support_library(
     ],
 )
 
+libc_support_library(
+    name = "__support_math_fsqrtl",
+    hdrs = ["src/__support/math/fsqrtl.h"],
+    deps = [
+        ":__support_fputil_sqrt",
+    ],
+)
+
 libc_support_library(
     name = "__support_math_inv_trigf_utils",
     hdrs = ["src/__support/math/inv_trigf_utils.h"],
@@ -4285,7 +4293,7 @@ libc_math_function(
 libc_math_function(
     name = "fsqrtl",
     additional_deps = [
-        ":__support_fputil_sqrt",
+        ":__support_math_fsqrtl",
     ],
 )

bassiounix

Thank you for you PR, you are on the right track with some changes.

libc/shared/math/fsqrtl.h

libc/src/__support/math/CMakeLists.txt

bassiounix · 2026-01-16T05:18:22Z

libc/src/__support/math/fsqrtl.h

+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_MATH_FSQRTL_H


Suggested change

#endif // LLVM_LIBC_SRC___SUPPORT_MATH_FSQRTL_H

#endif // LLVM_LIBC_SRC___SUPPORT_MATH_FSQRTL_H

bassiounix · 2026-01-16T05:19:00Z

libc/src/math/generic/fsqrtl.cpp

 #include "src/__support/FPUtil/generic/sqrt.h"
 #include "src/__support/common.h"
 #include "src/__support/macros/config.h"


Cleanup

Suggested change

#include "src/__support/FPUtil/generic/sqrt.h"

#include "src/__support/common.h"

#include "src/__support/macros/config.h"

bassiounix · 2026-01-16T05:20:25Z

libc/test/shared/shared_math_test.cpp

  EXPECT_FP_EQ(0x1p+0, LIBC_NAMESPACE::shared::exp2(0.0));
  EXPECT_FP_EQ(0x1p+0, LIBC_NAMESPACE::shared::exp10(0.0));
  EXPECT_FP_EQ(0x0p+0, LIBC_NAMESPACE::shared::expm1(0.0));
+  EXPECT_FP_EQ(0x0p+0, LIBC_NAMESPACE::shared::fsqrtl(0.0));


There's a new section for long double functions, please fetch the latest changes and move your function there

github-actions · 2026-01-16T05:22:49Z

⚠️ We detected that you are using a GitHub private e-mail address to contribute to the repo.
Please turn off Keep my email addresses private setting in your account.
See LLVM Developer Policy and LLVM Discourse for more information.

github-actions · 2026-01-16T05:23:13Z

✅ With the latest revision this PR passed the C/C++ code formatter.

github-actions · 2026-01-16T05:28:26Z

🐧 Linux x64 Test Results

✅ The build succeeded and no tests ran. This is expected in some build configurations.

Atharva062006 · 2026-01-16T18:10:26Z

@bassiounix i did all the recommended changes, does this look okay?

bassiounix · 2026-01-19T15:17:44Z

libc/test/shared/shared_math_test.cpp

 TEST(LlvmLibcSharedMathTest, AllLongDouble) {
  EXPECT_FP_EQ(0x0p+0L,
               LIBC_NAMESPACE::shared::dfmal(0x0.p+0L, 0x0.p+0L, 0x0.p+0L));
+  EXPECT_FP_EQ(0x0p+0, LIBC_NAMESPACE::shared::fsqrtl(0.0));


Please add the long literal type suffix

Atharva062006 · 2026-01-19T18:37:44Z

@bassiounix Done

bassiounix · 2026-01-23T20:08:15Z

libc/src/__support/math/fsqrtl.h

+
+namespace math {
+
+LIBC_INLINE static constexpr float fsqrt(long double x) {


Suggested change

LIBC_INLINE static constexpr float fsqrt(long double x) {

LIBC_INLINE static constexpr float fsqrtl(long double x) {

Atharva062006 · 2026-01-24T05:51:36Z

@bassiounix

bassiounix · 2026-01-25T00:04:54Z

please check code formatting

Atharva062006 · 2026-01-25T05:49:48Z

@bassiounix used clang-format, should be fixed

libc/shared/math/fsqrtl.h

bassiounix · 2026-01-26T18:15:22Z

⚠️ We detected that you are using a GitHub private e-mail address to contribute to the repo. Please turn off Keep my email addresses private setting in your account. See LLVM Developer Policy and LLVM Discourse for more information.

I can't accept this PR unless you resolve this.

bassiounix

LGTM.
Thank you for the refactor!

github-actions · 2026-01-28T20:13:04Z

@Atharva062006 Congratulations on having your first Pull Request (PR) merged into the LLVM Project!

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This PR refactors fsqrtl to be header only as discussed. No functional change intended. Test and build files were updated as required by the refactor Fixes llvm#175335

Atharva062006 requested review from aaronmondal, keith and rupprecht as code owners January 15, 2026 14:00

llvmbot added libc bazel "Peripheral" support tier build system: utils/bazel labels Jan 15, 2026

Atharva062006 mentioned this pull request Jan 15, 2026

[libc][math] Refactor fsqrtl to Header Only. #175335

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Atharva062006 added 5 commits January 25, 2026 11:03

[libc] Refactor fsqrtl to be header-only

a5a9392

added long literal type suffix

86e63fe

return value suffix to float

5323aaa

fixed fsqrtl naming

c4f6b6d

fixed formatting

d734ae5

Atharva062006 force-pushed the refactor-fsqrtl-header-only branch from 3da7e10 to d734ae5 Compare January 25, 2026 05:46

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libc/shared/math/fsqrtl.h Outdated Show resolved Hide resolved

applied suggested change

d7a04e2

Atharva062006 requested a review from bassiounix January 28, 2026 07:31

bassiounix approved these changes Jan 28, 2026

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fix formatting

c71163d

bassiounix enabled auto-merge (squash) January 28, 2026 20:07

bassiounix merged commit 18925d1 into llvm:main Jan 28, 2026
26 of 27 checks passed


		} // namespace LIBC_NAMESPACE_DECL

		#endif // LLVM_LIBC_SRC___SUPPORT_MATH_FSQRTL_H No newline at end of file

	#include "src/__support/FPUtil/generic/sqrt.h"
	#include "src/__support/common.h"
	#include "src/__support/macros/config.h"


		namespace math {

		LIBC_INLINE static constexpr float fsqrt(long double x) {

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