[libc-commits] [libc] [libc][math] Add POSIX math constants to math.h header. (PR #149150)

Wed Jul 16 13:03:19 PDT 2025

https://github.com/lntue updated https://github.com/llvm/llvm-project/pull/149150

>From eece7705e75abf701c4af458068cd066e905b9f9 Mon Sep 17 00:00:00 2001
From: Tue Ly <lntue.h at gmail.com>
Date: Wed, 16 Jul 2025 17:46:35 +0000
Subject: [PATCH 1/2] [libc][math] Add POSIX math constants to math.h header.

---
 libc/include/llvm-libc-macros/math-macros.h | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/libc/include/llvm-libc-macros/math-macros.h b/libc/include/llvm-libc-macros/math-macros.h
index 2f05d7544666e..5195292c7db58 100644
--- a/libc/include/llvm-libc-macros/math-macros.h
+++ b/libc/include/llvm-libc-macros/math-macros.h
@@ -50,4 +50,25 @@
 #define math_errhandling (MATH_ERRNO | MATH_ERREXCEPT)
 #endif
 
+// POSIX math constants
+// https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/math.h.html
+#define M_E (__extension__ 0x1.5bf0a8b145769p1)
+#define M_EGAMMA (__extension__ 0x1.2788cfc6fb619p-1)
+#define M_LOG2E (__extension__ 0x1.71547652b82fep0)
+#define M_LOG10E (__extension__ 0x1.bcb7b1526e50ep-2)
+#define M_LN2 (__extension__ 0x1.62e42fefa39efp-1)
+#define M_LN10 (__extension__ 0x1.26bb1bbb55516p1)
+#define M_PHI (__extension__ 0x1.9e3779b97f4a8p0)
+#define M_PI (__extension__ 0x1.921fb54442d18p1)
+#define M_PI_2 (__extension__ 0x1.921fb54442d18p0)
+#define M_PI_4 (__extension__ 0x1.921fb54442d18p-1)
+#define M_1_PI (__extension__ 0x1.45f306dc9c883p-2)
+#define M_1_SQRTPI (__extension__ 0x1.20dd750429b6dp-1)
+#define M_2_PI (__extension__ 0x1.45f306dc9c883p-1)
+#define M_2_SQRTPI (__extension__ 0x1.20dd750429b6dp0)
+#define M_SQRT2 (__extension__ 0x1.6a09e667f3bcdp0)
+#define M_SQRT3 (__extension__ 0x1.bb67ae8584caap0)
+#define M_SQRT1_2 (__extension__ 0x1.6a09e667f3bcdp-1)
+#define M_SQRT1_3 (__extension__ 0x1.279a74590331cp-1)
+
 #endif // LLVM_LIBC_MACROS_MATH_MACROS_H

>From a64a3e826d8565e745ab02ebdbed9a1231f59a10 Mon Sep 17 00:00:00 2001
From: Tue Ly <lntue.h at gmail.com>
Date: Wed, 16 Jul 2025 20:02:50 +0000
Subject: [PATCH 2/2] Add float, long double, float16, and float128 variants of
 the constants.

---
 libc/include/llvm-libc-macros/math-macros.h | 80 +++++++++++++++++++++
 1 file changed, 80 insertions(+)

diff --git a/libc/include/llvm-libc-macros/math-macros.h b/libc/include/llvm-libc-macros/math-macros.h
index 5195292c7db58..6697ce5b03851 100644
--- a/libc/include/llvm-libc-macros/math-macros.h
+++ b/libc/include/llvm-libc-macros/math-macros.h
@@ -71,4 +71,84 @@
 #define M_SQRT1_2 (__extension__ 0x1.6a09e667f3bcdp-1)
 #define M_SQRT1_3 (__extension__ 0x1.279a74590331cp-1)
 
+#define M_Ef (__extension__ 0x1.5bf0a8p1f)
+#define M_EGAMMAf (__extension__ 0x1.2788dp-1f)
+#define M_LOG2Ef (__extension__ 0x1.715476p0f)
+#define M_LOG10Ef (__extension__ 0x1.bcb7b2p-2f)
+#define M_LN2f (__extension__ 0x1.62e43p-1f)
+#define M_LN10f (__extension__ 0x1.26bb1cp1f)
+#define M_PHIf (__extension__ 0x1.9e377ap0f)
+#define M_PIf (__extension__ 0x1.921fb6p1f)
+#define M_PI_2f (__extension__ 0x1.921fb6p0f)
+#define M_PI_4f (__extension__ 0x1.921fb6p-1f)
+#define M_1_PIf (__extension__ 0x1.45f306p-2f)
+#define M_1_SQRTPIf (__extension__ 0x1.20dd76p-1f)
+#define M_2_PIf (__extension__ 0x1.45f306p-1f)
+#define M_2_SQRTPIf (__extension__ 0x1.20dd76p0f)
+#define M_SQRT2f (__extension__ 0x1.6a09e6p0f)
+#define M_SQRT3f (__extension__ 0x1.bb67aep0f)
+#define M_SQRT1_2f (__extension__ 0x1.6a09e6p-1f)
+#define M_SQRT1_3f (__extension__ 0x1.279a74p-1f)
+
+#define M_El (__extension__ 0x1.5bf0a8b1457695355fb8ac404e7ap1L)
+#define M_EGAMMAl (__extension__ 0x1.2788cfc6fb618f49a37c7f0202a6p-1L)
+#define M_LOG2El (__extension__ 0x1.71547652b82fe1777d0ffda0d23ap0L)
+#define M_LOG10El (__extension__ 0x1.bcb7b1526e50e32a6ab7555f5a68p-2L)
+#define M_LN2l (__extension__ 0x1.62e42fefa39ef35793c7673007e6p-1L)
+#define M_LN10l (__extension__ 0x1.26bb1bbb5551582dd4adac5705a6p1L)
+#define M_PHIl (__extension__ 0x1.9e3779b97f4a7c15f39cc0605ceep0L)
+#define M_PIl (__extension__ 0x1.921fb54442d18469898cc51701b8p1L)
+#define M_PI_2l (__extension__ 0x1.921fb54442d18469898cc51701b8p0L)
+#define M_PI_4l (__extension__ 0x1.921fb54442d18469898cc51701b8p-1L)
+#define M_1_PIl (__extension__ 0x1.45f306dc9c882a53f84eafa3ea6ap-2L)
+#define M_1_SQRTPIl (__extension__ 0x1.20dd750429b6d11ae3a914fed7fep-1L)
+#define M_2_PIl (__extension__ 0x1.45f306dc9c882a53f84eafa3ea6ap-1L)
+#define M_2_SQRTPIl (__extension__ 0x1.20dd750429b6d11ae3a914fed7fep0L)
+#define M_SQRT2l (__extension__ 0x1.6a09e667f3bcc908b2fb1366ea95p0L)
+#define M_SQRT3l (__extension__ 0x1.bb67ae8584caa73b25742d7078b8p0L)
+#define M_SQRT1_2l (__extension__ 0x1.6a09e667f3bcc908b2fb1366ea95p-1L)
+#define M_SQRT1_3l (__extension__ 0x1.279a74590331c4d218f81e4afb25p-1L)
+
+#ifdef __FLT16_MANT_DIG__
+#define M_Ef16 (__extension__ 0x1.5cp1f16)
+#define M_EGAMMAf16 (__extension__ 0x1.278p-1f16)
+#define M_LOG2Ef16 (__extension__ 0x1.714f16)
+#define M_LOG10Ef16 (__extension__ 0x1.bccp-2f16)
+#define M_LN2f16 (__extension__ 0x1.63p-1f16)
+#define M_LN10f16 (__extension__ 0x1.26cp1f16)
+#define M_PHIf16 (__extension__ 0x1.9e4p0f16)
+#define M_PIf16 (__extension__ 0x1.92p1f16)
+#define M_PI_2f16 (__extension__ 0x1.92p0f16)
+#define M_PI_4f16 (__extension__ 0x1.92p-1f16)
+#define M_1_PIf16 (__extension__ 0x1.46p-2f16)
+#define M_1_SQRTPIf16 (__extension__ 0x1.20cp-1f16)
+#define M_2_PIf16 (__extension__ 0x1.46p-1f16)
+#define M_2_SQRTPIf16 (__extension__ 0x1.20cp0f16)
+#define M_SQRT2f16 (__extension__ 0x1.6ap0f16)
+#define M_SQRT3f16 (__extension__ 0x1.bb8p0f16)
+#define M_SQRT1_2f16 (__extension__ 0x1.6ap-1f16)
+#define M_SQRT1_3f16 (__extension__ 0x1.278p-1f16)
+#endif // __FLT16_MANT_DIG__
+
+#ifdef __SIZEOF_FLOAT128__
+#define M_Ef128 (__extension__ 0x1.5bf0a8b1457695355fb8ac404e7ap1q)
+#define M_EGAMMAf128 (__extension__ 0x1.2788cfc6fb618f49a37c7f0202a6p-1q)
+#define M_LOG2Ef128 (__extension__ 0x1.71547652b82fe1777d0ffda0d23ap0q)
+#define M_LOG10Ef128 (__extension__ 0x1.bcb7b1526e50e32a6ab7555f5a68p-2q)
+#define M_LN2f128 (__extension__ 0x1.62e42fefa39ef35793c7673007e6p-1q)
+#define M_LN10f128 (__extension__ 0x1.26bb1bbb5551582dd4adac5705a6p1q)
+#define M_PHIf128 (__extension__ 0x1.9e3779b97f4a7c15f39cc0605ceep0q)
+#define M_PIf128 (__extension__ 0x1.921fb54442d18469898cc51701b8p1q)
+#define M_PI_2f128 (__extension__ 0x1.921fb54442d18469898cc51701b8p0q)
+#define M_PI_4f128 (__extension__ 0x1.921fb54442d18469898cc51701b8p-1q)
+#define M_1_PIf128 (__extension__ 0x1.45f306dc9c882a53f84eafa3ea6ap-2q)
+#define M_1_SQRTPIf128 (__extension__ 0x1.20dd750429b6d11ae3a914fed7fep-1q)
+#define M_2_PIf128 (__extension__ 0x1.45f306dc9c882a53f84eafa3ea6ap-1q)
+#define M_2_SQRTPIf128 (__extension__ 0x1.20dd750429b6d11ae3a914fed7fep0q)
+#define M_SQRT2f128 (__extension__ 0x1.6a09e667f3bcc908b2fb1366ea95p0q)
+#define M_SQRT3f128 (__extension__ 0x1.bb67ae8584caa73b25742d7078b8p0q)
+#define M_SQRT1_2f128 (__extension__ 0x1.6a09e667f3bcc908b2fb1366ea95p-1q)
+#define M_SQRT1_3f128 (__extension__ 0x1.279a74590331c4d218f81e4afb25p-1q)
+#endif // __SIZEOF_FLOAT128__
+
 #endif // LLVM_LIBC_MACROS_MATH_MACROS_H

