[libc-commits] [libc] [libc][math] Add isnanf128 (PR #199206)
via libc-commits
libc-commits at lists.llvm.org
Fri May 22 05:21:24 PDT 2026
llvmorg-github-actions[bot] wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-backend-risc-v
Author: Vedant Neve (0bVdnt)
<details>
<summary>Changes</summary>
## Summary
- Add a fputil-based isnanf128 implementation and wire it into libc math entrypoints, public math header generation, and shared math wrappers.
- Add smoke test coverage for float128 NaN classification and shared math runtime/constexpr coverage.
Part of #<!-- -->195400
---
Full diff: https://github.com/llvm/llvm-project/pull/199206.diff
22 Files Affected:
- (modified) libc/config/baremetal/aarch64/entrypoints.txt (+1)
- (modified) libc/config/baremetal/arm/entrypoints.txt (+1)
- (modified) libc/config/baremetal/riscv/entrypoints.txt (+1)
- (modified) libc/config/darwin/aarch64/entrypoints.txt (+1)
- (modified) libc/config/linux/aarch64/entrypoints.txt (+1)
- (modified) libc/config/linux/riscv/entrypoints.txt (+1)
- (modified) libc/config/linux/x86_64/entrypoints.txt (+1)
- (modified) libc/include/math.yaml (+7)
- (modified) libc/shared/math.h (+1)
- (added) libc/shared/math/isnanf128.h (+29)
- (modified) libc/src/__support/math/CMakeLists.txt (+10)
- (added) libc/src/__support/math/isnanf128.h (+31)
- (modified) libc/src/math/CMakeLists.txt (+1)
- (modified) libc/src/math/generic/CMakeLists.txt (+10)
- (added) libc/src/math/generic/isnanf128.cpp (+16)
- (added) libc/src/math/isnanf128.h (+21)
- (modified) libc/test/shared/CMakeLists.txt (+2)
- (modified) libc/test/shared/shared_math_constexpr_test.cpp (+1)
- (modified) libc/test/shared/shared_math_test.cpp (+1)
- (modified) libc/test/src/math/smoke/CMakeLists.txt (+12)
- (added) libc/test/src/math/smoke/IsNanTest.h (+56)
- (added) libc/test/src/math/smoke/isnanf128_test.cpp (+13)
``````````diff
diff --git a/libc/config/baremetal/aarch64/entrypoints.txt b/libc/config/baremetal/aarch64/entrypoints.txt
index dcb50135232e2..6fa1d22d726c3 100644
--- a/libc/config/baremetal/aarch64/entrypoints.txt
+++ b/libc/config/baremetal/aarch64/entrypoints.txt
@@ -758,6 +758,7 @@ if(LIBC_TYPES_HAS_FLOAT128)
libc.src.math.getpayloadf128
libc.src.math.ilogbf128
libc.src.math.iscanonicalf128
+ libc.src.math.isnanf128
libc.src.math.issignalingf128
libc.src.math.ldexpf128
libc.src.math.llogbf128
diff --git a/libc/config/baremetal/arm/entrypoints.txt b/libc/config/baremetal/arm/entrypoints.txt
index fac62bac939cc..c2aa17e125b88 100644
--- a/libc/config/baremetal/arm/entrypoints.txt
+++ b/libc/config/baremetal/arm/entrypoints.txt
@@ -769,6 +769,7 @@ if(LIBC_TYPES_HAS_FLOAT128)
libc.src.math.getpayloadf128
libc.src.math.ilogbf128
libc.src.math.iscanonicalf128
+ libc.src.math.isnanf128
libc.src.math.issignalingf128
libc.src.math.ldexpf128
libc.src.math.llogbf128
diff --git a/libc/config/baremetal/riscv/entrypoints.txt b/libc/config/baremetal/riscv/entrypoints.txt
index a3b96225ff09d..05c48ed0e1f51 100644
--- a/libc/config/baremetal/riscv/entrypoints.txt
+++ b/libc/config/baremetal/riscv/entrypoints.txt
@@ -766,6 +766,7 @@ if(LIBC_TYPES_HAS_FLOAT128)
libc.src.math.getpayloadf128
libc.src.math.ilogbf128
libc.src.math.iscanonicalf128
+ libc.src.math.isnanf128
libc.src.math.issignalingf128
libc.src.math.ldexpf128
libc.src.math.llogbf128
diff --git a/libc/config/darwin/aarch64/entrypoints.txt b/libc/config/darwin/aarch64/entrypoints.txt
index 914d2b7918da1..30b4709efe74f 100644
--- a/libc/config/darwin/aarch64/entrypoints.txt
+++ b/libc/config/darwin/aarch64/entrypoints.txt
@@ -579,6 +579,7 @@ if(LIBC_TYPES_HAS_FLOAT128)
libc.src.math.getpayloadf128
libc.src.math.ilogbf128
libc.src.math.iscanonicalf128
+ libc.src.math.isnanf128
libc.src.math.issignalingf128
libc.src.math.ldexpf128
libc.src.math.llogbf128
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index c7458ef36c941..d57855708ae0c 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -869,6 +869,7 @@ if(LIBC_TYPES_HAS_FLOAT128)
libc.src.math.getpayloadf128
libc.src.math.ilogbf128
libc.src.math.iscanonicalf128
+ libc.src.math.isnanf128
libc.src.math.issignalingf128
libc.src.math.ldexpf128
libc.src.math.llogbf128
diff --git a/libc/config/linux/riscv/entrypoints.txt b/libc/config/linux/riscv/entrypoints.txt
index e3336420cbbcc..fa0dbd16437e7 100644
--- a/libc/config/linux/riscv/entrypoints.txt
+++ b/libc/config/linux/riscv/entrypoints.txt
@@ -890,6 +890,7 @@ if(LIBC_TYPES_HAS_FLOAT128)
libc.src.math.getpayloadf128
libc.src.math.ilogbf128
libc.src.math.iscanonicalf128
+ libc.src.math.isnanf128
libc.src.math.issignalingf128
libc.src.math.ldexpf128
libc.src.math.llogbf128
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 3c3b0e835429f..7fdee9f3d2b81 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -955,6 +955,7 @@ if(LIBC_TYPES_HAS_FLOAT128)
libc.src.math.getpayloadf128
libc.src.math.ilogbf128
libc.src.math.iscanonicalf128
+ libc.src.math.isnanf128
libc.src.math.issignalingf128
libc.src.math.ldexpf128
libc.src.math.llogbf128
diff --git a/libc/include/math.yaml b/libc/include/math.yaml
index 3984a665b234b..225801518686f 100644
--- a/libc/include/math.yaml
+++ b/libc/include/math.yaml
@@ -1600,6 +1600,13 @@ functions:
return_type: int
arguments:
- type: float
+ - name: isnanf128
+ standards:
+ - BSDExtensions
+ return_type: int
+ arguments:
+ - type: float128
+ guard: LIBC_TYPES_HAS_FLOAT128
- name: isnanl
standards:
- BSDExtensions
diff --git a/libc/shared/math.h b/libc/shared/math.h
index 2baeb07294a3b..aa2efab7336b5 100644
--- a/libc/shared/math.h
+++ b/libc/shared/math.h
@@ -291,6 +291,7 @@
// TODO: isnan is a macro in <math.h>
// #include "math/isnan.h"
#include "math/isnanf.h"
+#include "math/isnanf128.h"
#include "math/isnanl.h"
// TODO: issignaling is a macro in <math.h>
// #include "math/issignaling.h"
diff --git a/libc/shared/math/isnanf128.h b/libc/shared/math/isnanf128.h
new file mode 100644
index 0000000000000..3d9ee44b6070d
--- /dev/null
+++ b/libc/shared/math/isnanf128.h
@@ -0,0 +1,29 @@
+//===-- Shared isnanf128 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_ISNANF128_H
+#define LLVM_LIBC_SHARED_MATH_ISNANF128_H
+
+#include "include/llvm-libc-types/float128.h"
+
+#ifdef LIBC_TYPES_HAS_FLOAT128
+
+#include "shared/libc_common.h"
+#include "src/__support/math/isnanf128.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace shared {
+
+using math::isnanf128;
+
+} // namespace shared
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LIBC_TYPES_HAS_FLOAT128
+
+#endif // LLVM_LIBC_SHARED_MATH_ISNANF128_H
diff --git a/libc/src/__support/math/CMakeLists.txt b/libc/src/__support/math/CMakeLists.txt
index 9e3ec26cdc881..8e946ccbb4c57 100644
--- a/libc/src/__support/math/CMakeLists.txt
+++ b/libc/src/__support/math/CMakeLists.txt
@@ -1695,6 +1695,16 @@ add_header_library(
libc.src.__support.macros.config
)
+add_header_library(
+ isnanf128
+ HDRS
+ isnanf128.h
+ DEPENDS
+ libc.include.llvm-libc-types.float128
+ libc.src.__support.FPUtil.fp_bits
+ libc.src.__support.macros.config
+)
+
add_header_library(
isnanl
HDRS
diff --git a/libc/src/__support/math/isnanf128.h b/libc/src/__support/math/isnanf128.h
new file mode 100644
index 0000000000000..4676764808a91
--- /dev/null
+++ b/libc/src/__support/math/isnanf128.h
@@ -0,0 +1,31 @@
+//===-- Implementation header for isnanf128 ---------------------*- 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_ISNANF128_H
+#define LLVM_LIBC_SRC___SUPPORT_MATH_ISNANF128_H
+
+#include "include/llvm-libc-types/float128.h"
+
+#ifdef LIBC_TYPES_HAS_FLOAT128
+
+#include "src/__support/FPUtil/FPBits.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace math {
+
+LIBC_INLINE LIBC_CONSTEXPR int isnanf128(float128 x) {
+ return fputil::FPBits<float128>(x).is_nan();
+}
+
+} // namespace math
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LIBC_TYPES_HAS_FLOAT128
+
+#endif // LLVM_LIBC_SRC___SUPPORT_MATH_ISNANF128_H
diff --git a/libc/src/math/CMakeLists.txt b/libc/src/math/CMakeLists.txt
index b53817e2a1729..3d79e42c032a5 100644
--- a/libc/src/math/CMakeLists.txt
+++ b/libc/src/math/CMakeLists.txt
@@ -367,6 +367,7 @@ add_math_entrypoint_object(ilogbbf16)
add_math_entrypoint_object(isnan)
add_math_entrypoint_object(isnanf)
+add_math_entrypoint_object(isnanf128)
add_math_entrypoint_object(isnanl)
add_math_entrypoint_object(issignaling)
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
index 7ccbddba07b8d..de8171a3322c7 100644
--- a/libc/src/math/generic/CMakeLists.txt
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -3031,6 +3031,16 @@ add_entrypoint_object(
libc.src.__support.math.isnanf
)
+add_entrypoint_object(
+ isnanf128
+ SRCS
+ isnanf128.cpp
+ HDRS
+ ../isnanf128.h
+ DEPENDS
+ libc.src.__support.math.isnanf128
+)
+
add_entrypoint_object(
isnanl
SRCS
diff --git a/libc/src/math/generic/isnanf128.cpp b/libc/src/math/generic/isnanf128.cpp
new file mode 100644
index 0000000000000..919136fe3e4fb
--- /dev/null
+++ b/libc/src/math/generic/isnanf128.cpp
@@ -0,0 +1,16 @@
+//===-- Implementation of isnanf128 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/isnanf128.h"
+#include "src/__support/math/isnanf128.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, isnanf128, (float128 x)) { return math::isnanf128(x); }
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/math/isnanf128.h b/libc/src/math/isnanf128.h
new file mode 100644
index 0000000000000..968e858519421
--- /dev/null
+++ b/libc/src/math/isnanf128.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for isnanf128 ---------------------*- 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_ISNANF128_H
+#define LLVM_LIBC_SRC_MATH_ISNANF128_H
+
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int isnanf128(float128 x);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_MATH_ISNANF128_H
diff --git a/libc/test/shared/CMakeLists.txt b/libc/test/shared/CMakeLists.txt
index 84a8d4bf79b3d..c9126b8767c32 100644
--- a/libc/test/shared/CMakeLists.txt
+++ b/libc/test/shared/CMakeLists.txt
@@ -286,6 +286,7 @@ add_fp_unittest(
libc.src.__support.math.iscanonicall
libc.src.__support.math.isnan
libc.src.__support.math.isnanf
+ libc.src.__support.math.isnanf128
libc.src.__support.math.isnanl
libc.src.__support.math.issignaling
libc.src.__support.math.issignalingbf16
@@ -658,6 +659,7 @@ add_fp_unittest(
libc.src.__support.math.iscanonicall
libc.src.__support.math.isnan
libc.src.__support.math.isnanf
+ libc.src.__support.math.isnanf128
libc.src.__support.math.isnanl
libc.src.__support.math.issignaling
libc.src.__support.math.issignalingbf16
diff --git a/libc/test/shared/shared_math_constexpr_test.cpp b/libc/test/shared/shared_math_constexpr_test.cpp
index 1e7ccb623fc55..d186acc05c47e 100644
--- a/libc/test/shared/shared_math_constexpr_test.cpp
+++ b/libc/test/shared/shared_math_constexpr_test.cpp
@@ -490,6 +490,7 @@ static_assert(float128(0.0) ==
float128(0.0)));
static_assert(float128(0.0) == LIBC_NAMESPACE::shared::rintf128(float128(0.0)));
static_assert(1 == LIBC_NAMESPACE::shared::iscanonicalf128(float128(0.0)));
+static_assert(0 == LIBC_NAMESPACE::shared::isnanf128(float128(0.0)));
static_assert(0.0 == LIBC_NAMESPACE::shared::issignalingf128(float128(0.0)));
static_assert(1 == [] {
const char arg{};
diff --git a/libc/test/shared/shared_math_test.cpp b/libc/test/shared/shared_math_test.cpp
index 634778380dc8e..8dd8d69635aab 100644
--- a/libc/test/shared/shared_math_test.cpp
+++ b/libc/test/shared/shared_math_test.cpp
@@ -739,6 +739,7 @@ TEST(LlvmLibcSharedMathTest, AllFloat128) {
LIBC_NAMESPACE::shared::nearbyintf128(float128(0.0)));
EXPECT_FP_EQ(float128(0.0), LIBC_NAMESPACE::shared::rintf128(float128(0.0)));
EXPECT_EQ(1, LIBC_NAMESPACE::shared::iscanonicalf128(float128(0.0)));
+ EXPECT_EQ(0, LIBC_NAMESPACE::shared::isnanf128(float128(0.0)));
EXPECT_EQ(0, LIBC_NAMESPACE::shared::issignalingf128(float128(0.0)));
EXPECT_TRUE(FPBits(LIBC_NAMESPACE::shared::nanf128("")).is_nan());
EXPECT_FP_EQ(float128(0.0), LIBC_NAMESPACE::shared::roundf128(float128(0.0)));
diff --git a/libc/test/src/math/smoke/CMakeLists.txt b/libc/test/src/math/smoke/CMakeLists.txt
index 28b85b1a25bbd..2a38ce6b1a07a 100644
--- a/libc/test/src/math/smoke/CMakeLists.txt
+++ b/libc/test/src/math/smoke/CMakeLists.txt
@@ -521,6 +521,18 @@ add_fp_unittest(
libc.src.__support.FPUtil.bfloat16
)
+add_fp_unittest(
+ isnanf128_test
+ SUITE
+ libc-math-smoke-tests
+ SRCS
+ isnanf128_test.cpp
+ HDRS
+ IsNanTest.h
+ DEPENDS
+ libc.src.math.isnanf128
+)
+
add_fp_unittest(
ceil_test
SUITE
diff --git a/libc/test/src/math/smoke/IsNanTest.h b/libc/test/src/math/smoke/IsNanTest.h
new file mode 100644
index 0000000000000..8fe53f81a849b
--- /dev/null
+++ b/libc/test/src/math/smoke/IsNanTest.h
@@ -0,0 +1,56 @@
+//===-- Utility class to test different flavors of isnan --------*- 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_TEST_SRC_MATH_SMOKE_ISNANTEST_H
+#define LLVM_LIBC_TEST_SRC_MATH_SMOKE_ISNANTEST_H
+
+#include "test/UnitTest/FEnvSafeTest.h"
+#include "test/UnitTest/FPMatcher.h"
+#include "test/UnitTest/Test.h"
+
+template <typename T>
+class IsNanTest : public LIBC_NAMESPACE::testing::FEnvSafeTest {
+
+ DECLARE_SPECIAL_CONSTANTS(T)
+
+public:
+ typedef int (*IsNanFunc)(T);
+
+ void testSpecialNumbers(IsNanFunc func) {
+ EXPECT_EQ(func(aNaN), 1);
+ EXPECT_EQ(func(neg_aNaN), 1);
+ EXPECT_EQ(func(sNaN), 1);
+ EXPECT_EQ(func(neg_sNaN), 1);
+ EXPECT_EQ(func(inf), 0);
+ EXPECT_EQ(func(neg_inf), 0);
+ EXPECT_EQ(func(min_normal), 0);
+ EXPECT_EQ(func(max_normal), 0);
+ EXPECT_EQ(func(neg_max_normal), 0);
+ EXPECT_EQ(func(min_denormal), 0);
+ EXPECT_EQ(func(neg_min_denormal), 0);
+ EXPECT_EQ(func(max_denormal), 0);
+ EXPECT_EQ(func(zero), 0);
+ EXPECT_EQ(func(neg_zero), 0);
+ }
+
+ void testRoundedNumbers(IsNanFunc func) {
+ EXPECT_EQ(func(T(1.0)), 0);
+ EXPECT_EQ(func(T(-1.0)), 0);
+ EXPECT_EQ(func(T(10.0)), 0);
+ EXPECT_EQ(func(T(-10.0)), 0);
+ EXPECT_EQ(func(T(1234.0)), 0);
+ EXPECT_EQ(func(T(-1234.0)), 0);
+ }
+};
+
+#define LIST_ISNAN_TESTS(T, func) \
+ using LlvmLibcIsNanTest = IsNanTest<T>; \
+ TEST_F(LlvmLibcIsNanTest, SpecialNumbers) { testSpecialNumbers(&func); } \
+ TEST_F(LlvmLibcIsNanTest, RoundedNumbers) { testRoundedNumbers(&func); }
+
+#endif // LLVM_LIBC_TEST_SRC_MATH_SMOKE_ISNANTEST_H
diff --git a/libc/test/src/math/smoke/isnanf128_test.cpp b/libc/test/src/math/smoke/isnanf128_test.cpp
new file mode 100644
index 0000000000000..061370adce558
--- /dev/null
+++ b/libc/test/src/math/smoke/isnanf128_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for isnanf128 -------------------------------------------===//
+//
+// 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 "IsNanTest.h"
+
+#include "src/math/isnanf128.h"
+
+LIST_ISNAN_TESTS(float128, LIBC_NAMESPACE::isnanf128)
``````````
</details>
https://github.com/llvm/llvm-project/pull/199206
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