[libc-commits] [libc] [libc] Float128 Emulation in LLVM libc (PR #200565)
via libc-commits
libc-commits at lists.llvm.org
Wed Jun 3 01:11:09 PDT 2026
https://github.com/Sukumarsawant updated https://github.com/llvm/llvm-project/pull/200565
>From d076a3641e67df6580c2ea767f2545e35ccb9ee8 Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Sat, 30 May 2026 02:08:42 +0530
Subject: [PATCH 1/9] test: float128 skeleton
---
libc/src/__support/FPUtil/CMakeLists.txt | 11 ++++++
libc/src/__support/FPUtil/float128.h | 45 ++++++++++++++++++++++++
2 files changed, 56 insertions(+)
create mode 100644 libc/src/__support/FPUtil/float128.h
diff --git a/libc/src/__support/FPUtil/CMakeLists.txt b/libc/src/__support/FPUtil/CMakeLists.txt
index d45dd82560788..a88986b4992f8 100644
--- a/libc/src/__support/FPUtil/CMakeLists.txt
+++ b/libc/src/__support/FPUtil/CMakeLists.txt
@@ -294,4 +294,15 @@ add_header_library(
libc.src.__support.macros.properties.types
)
+add_header_library(
+ float128
+ HDRS
+ float128.h
+ DEPENDS
+ .fp_bits
+ libc.hdr.fenv_macros
+ libc.src.__support.CPP.bit
+ libc.src.__support.uint128
+)
+
add_subdirectory(generic)
diff --git a/libc/src/__support/FPUtil/float128.h b/libc/src/__support/FPUtil/float128.h
new file mode 100644
index 0000000000000..73f450f1d41a8
--- /dev/null
+++ b/libc/src/__support/FPUtil/float128.h
@@ -0,0 +1,45 @@
+//===-- Utilities for Float128 data type -----------------------*- 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_FPUTIL_FLOAT128_H
+#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_FLOAT128_H
+
+#include "FPBits.h"
+#include "hdr/fenv_macros.h"
+#include "src/__support/CPP/bit.h"
+#include "src/__support/uint128.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace fputil {
+
+struct Float128 {
+ UInt128 bits;
+ // Testing
+ constexpr Float128() = default;
+ /* TODO: precision
+ TODO: explicit so it does not convert without warn ( Done )
+ VERIFY : template <cpp::enable_if_t<fputil::get_fp_type<Double>() ==
+ fputil::FPType::IEEE754_Binary64,
+ int> = 0>
+ */
+ constexpr explicit Float128(double x) {
+ FPBits<double> x_bits(x);
+ uint64_t val = x_bits.uintval();
+ bits = static_cast<UInt128>(val) << 64;
+ }
+
+ constexpr explicit operator double() const {
+ uint64_t val = static_cast<uint64_t>(bits >> 64U);
+ return cpp::bit_cast<double>(val);
+ }
+};
+
+} // namespace fputil
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_FPUTIL_FLOAT128_H
>From 098b0dec5ed583a29ffae25729b21d360beeface Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Tue, 2 Jun 2026 14:00:26 +0530
Subject: [PATCH 2/9] Add small smoke test
---
.../CPP/type_traits/is_floating_point.h | 2 +-
libc/src/__support/FPUtil/CMakeLists.txt | 4 +-
libc/src/__support/FPUtil/FPBits.h | 13 +++++-
libc/src/__support/FPUtil/float128.h | 41 +++++++++++--------
libc/src/__support/macros/properties/types.h | 8 ++++
libc/test/src/math/smoke/CMakeLists.txt | 10 +++++
libc/test/src/math/smoke/float128_test.cpp | 25 +++++++++++
7 files changed, 81 insertions(+), 22 deletions(-)
create mode 100644 libc/test/src/math/smoke/float128_test.cpp
diff --git a/libc/src/__support/CPP/type_traits/is_floating_point.h b/libc/src/__support/CPP/type_traits/is_floating_point.h
index 9dc77ad7ee0ea..ab4191868517e 100644
--- a/libc/src/__support/CPP/type_traits/is_floating_point.h
+++ b/libc/src/__support/CPP/type_traits/is_floating_point.h
@@ -37,7 +37,7 @@ template <typename T> struct is_floating_point {
float128
#endif
,
- bfloat16>();
+ bfloat16, fputil::Float128>();
};
template <typename T>
LIBC_INLINE_VAR constexpr bool is_floating_point_v =
diff --git a/libc/src/__support/FPUtil/CMakeLists.txt b/libc/src/__support/FPUtil/CMakeLists.txt
index a88986b4992f8..20e1c01bb8ca1 100644
--- a/libc/src/__support/FPUtil/CMakeLists.txt
+++ b/libc/src/__support/FPUtil/CMakeLists.txt
@@ -299,9 +299,9 @@ add_header_library(
HDRS
float128.h
DEPENDS
- .fp_bits
- libc.hdr.fenv_macros
libc.src.__support.CPP.bit
+ libc.src.__support.macros.attributes
+ libc.src.__support.macros.config
libc.src.__support.uint128
)
diff --git a/libc/src/__support/FPUtil/FPBits.h b/libc/src/__support/FPUtil/FPBits.h
index c52699e17e225..5b7461a44cff5 100644
--- a/libc/src/__support/FPUtil/FPBits.h
+++ b/libc/src/__support/FPUtil/FPBits.h
@@ -37,7 +37,8 @@ enum class FPType {
IEEE754_Binary64,
IEEE754_Binary128,
X86_Binary80,
- BFloat16
+ BFloat16,
+ Float128
};
// The classes hierarchy is as follows:
@@ -146,6 +147,14 @@ template <> struct FPLayout<FPType::BFloat16> {
LIBC_INLINE_VAR static constexpr int FRACTION_LEN = SIG_LEN;
};
+template <> struct FPLayout<FPType::Float128> {
+ using StorageType = UInt128;
+ LIBC_INLINE_VAR static constexpr int SIGN_LEN = 1;
+ LIBC_INLINE_VAR static constexpr int EXP_LEN = 15;
+ LIBC_INLINE_VAR static constexpr int SIG_LEN = 112;
+ LIBC_INLINE_VAR static constexpr int FRACTION_LEN = SIG_LEN;
+};
+
// FPStorage derives useful constants from the FPLayout above.
template <FPType fp_type> struct FPStorage : public FPLayout<fp_type> {
using UP = FPLayout<fp_type>;
@@ -813,6 +822,8 @@ template <typename T> LIBC_INLINE static constexpr FPType get_fp_type() {
#endif
else if constexpr (cpp::is_same_v<UnqualT, bfloat16>)
return FPType::BFloat16;
+ else if constexpr (cpp::is_same_v<UnqualT, Float128>)
+ return FPType::Float128;
else
static_assert(cpp::always_false<UnqualT>, "Unsupported type");
}
diff --git a/libc/src/__support/FPUtil/float128.h b/libc/src/__support/FPUtil/float128.h
index 73f450f1d41a8..ca5c49ddf11d7 100644
--- a/libc/src/__support/FPUtil/float128.h
+++ b/libc/src/__support/FPUtil/float128.h
@@ -1,4 +1,8 @@
+<<<<<<< HEAD
//===-- Utilities for Float128 data type -----------------------*- C++ -*-===//
+=======
+//===-- Definition for Float128 data type -----------------------*- C++ -*-===//
+>>>>>>> f128-test
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
@@ -9,33 +13,34 @@
#ifndef LLVM_LIBC_SRC___SUPPORT_FPUTIL_FLOAT128_H
#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_FLOAT128_H
-#include "FPBits.h"
-#include "hdr/fenv_macros.h"
-#include "src/__support/CPP/bit.h"
+#include "src/__support/CPP/bit.h" // cpp::bit_cast
+#include "src/__support/macros/attributes.h"
+#include "src/__support/macros/config.h"
#include "src/__support/uint128.h"
+#include <stdint.h>
namespace LIBC_NAMESPACE_DECL {
namespace fputil {
struct Float128 {
UInt128 bits;
- // Testing
- constexpr Float128() = default;
- /* TODO: precision
- TODO: explicit so it does not convert without warn ( Done )
- VERIFY : template <cpp::enable_if_t<fputil::get_fp_type<Double>() ==
- fputil::FPType::IEEE754_Binary64,
- int> = 0>
- */
- constexpr explicit Float128(double x) {
- FPBits<double> x_bits(x);
- uint64_t val = x_bits.uintval();
- bits = static_cast<UInt128>(val) << 64;
+
+ LIBC_INLINE Float128() = default;
+
+ LIBC_INLINE constexpr explicit Float128(double x) : bits(0) {
+ uint64_t d = cpp::bit_cast<uint64_t>(x);
+ bits = static_cast<UInt128>(d) << 64U;
}
- constexpr explicit operator double() const {
- uint64_t val = static_cast<uint64_t>(bits >> 64U);
- return cpp::bit_cast<double>(val);
+ LIBC_INLINE constexpr explicit operator double() const {
+ return cpp::bit_cast<double>(static_cast<uint64_t>(bits >> 64U));
+ }
+
+ LIBC_INLINE constexpr bool operator==(Float128 other) const {
+ return bits == other.bits;
+ }
+ LIBC_INLINE constexpr bool operator!=(Float128 other) const {
+ return bits != other.bits;
}
};
diff --git a/libc/src/__support/macros/properties/types.h b/libc/src/__support/macros/properties/types.h
index 3259c8a6a1d12..d94f6068984df 100644
--- a/libc/src/__support/macros/properties/types.h
+++ b/libc/src/__support/macros/properties/types.h
@@ -58,6 +58,14 @@ using float16 = _Float16;
// LIBC_TYPES_HAS_FLOAT128 and 'float128' type are provided by
// "include/llvm-libc-types/float128.h"
+// -- Emulated float128 support ------------------------------------------------
+// Float128 is always available regardless of native __float128 support.
+namespace LIBC_NAMESPACE_DECL {
+namespace fputil {
+struct Float128;
+}
+} // namespace LIBC_NAMESPACE_DECL
+
// -- bfloat16 support ---------------------------------------------------------
namespace LIBC_NAMESPACE_DECL {
diff --git a/libc/test/src/math/smoke/CMakeLists.txt b/libc/test/src/math/smoke/CMakeLists.txt
index bb462afb71b91..bc911ea8a798f 100644
--- a/libc/test/src/math/smoke/CMakeLists.txt
+++ b/libc/test/src/math/smoke/CMakeLists.txt
@@ -1,6 +1,16 @@
add_custom_target(libc-math-smoke-tests)
add_dependencies(libc-math-unittests libc-math-smoke-tests)
+add_libc_unittest(
+ float128_test
+ SUITE
+ libc-math-smoke-tests
+ SRCS
+ float128_test.cpp
+ DEPENDS
+ libc.src.__support.FPUtil.float128
+)
+
add_fp_unittest(
cosf_test
SUITE
diff --git a/libc/test/src/math/smoke/float128_test.cpp b/libc/test/src/math/smoke/float128_test.cpp
new file mode 100644
index 0000000000000..738e5ec703f00
--- /dev/null
+++ b/libc/test/src/math/smoke/float128_test.cpp
@@ -0,0 +1,25 @@
+//===-- Unittests for Float128 emulated type -----------------------------===//
+//
+// 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/__support/FPUtil/float128.h"
+#include "src/__support/uint128.h"
+#include "test/UnitTest/Test.h"
+
+using LIBC_NAMESPACE::fputil::Float128;
+
+TEST(LlvmLibcFloat128Test, DefaultConstructor) {
+ Float128 x;
+ (void)x;
+}
+
+TEST(LlvmLibcFloat128Test, Equality) {
+ Float128 a(1.0), b(1.0), c(2.0);
+ ASSERT_TRUE(a == b);
+ ASSERT_TRUE(a != c);
+ ASSERT_TRUE(b != c);
+}
>From 2f45df239d2aa24e748d40d64e9898f74449c41d Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Tue, 2 Jun 2026 14:06:05 +0530
Subject: [PATCH 3/9] nit
---
libc/src/__support/FPUtil/float128.h | 4 ----
1 file changed, 4 deletions(-)
diff --git a/libc/src/__support/FPUtil/float128.h b/libc/src/__support/FPUtil/float128.h
index ca5c49ddf11d7..c7835d7376853 100644
--- a/libc/src/__support/FPUtil/float128.h
+++ b/libc/src/__support/FPUtil/float128.h
@@ -1,8 +1,4 @@
-<<<<<<< HEAD
-//===-- Utilities for Float128 data type -----------------------*- C++ -*-===//
-=======
//===-- Definition for Float128 data type -----------------------*- C++ -*-===//
->>>>>>> f128-test
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
>From 680c1664cef2d8ddc1e8422b7f02d2e87f07f846 Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Tue, 2 Jun 2026 15:13:25 +0530
Subject: [PATCH 4/9] nit
---
libc/src/__support/FPUtil/float128.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/libc/src/__support/FPUtil/float128.h b/libc/src/__support/FPUtil/float128.h
index c7835d7376853..cc72692e8a22f 100644
--- a/libc/src/__support/FPUtil/float128.h
+++ b/libc/src/__support/FPUtil/float128.h
@@ -9,7 +9,7 @@
#ifndef LLVM_LIBC_SRC___SUPPORT_FPUTIL_FLOAT128_H
#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_FLOAT128_H
-#include "src/__support/CPP/bit.h" // cpp::bit_cast
+#include "src/__support/CPP/bit.h"
#include "src/__support/macros/attributes.h"
#include "src/__support/macros/config.h"
#include "src/__support/uint128.h"
@@ -24,8 +24,8 @@ struct Float128 {
LIBC_INLINE Float128() = default;
LIBC_INLINE constexpr explicit Float128(double x) : bits(0) {
- uint64_t d = cpp::bit_cast<uint64_t>(x);
- bits = static_cast<UInt128>(d) << 64U;
+ uint64_t x_bits = cpp::bit_cast<uint64_t>(x);
+ bits = static_cast<UInt128>(x_bits) << 64U;
}
LIBC_INLINE constexpr explicit operator double() const {
>From f25b345a636cca7028b67ea84e95e5cd05be3a96 Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Tue, 2 Jun 2026 20:52:36 +0530
Subject: [PATCH 5/9] temp commit for rebase
---
libc/src/__support/CPP/type_traits/is_floating_point.h | 5 ++++-
libc/src/__support/FPUtil/cast.h | 4 +++-
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/libc/src/__support/CPP/type_traits/is_floating_point.h b/libc/src/__support/CPP/type_traits/is_floating_point.h
index ab4191868517e..d53dcd4961ab6 100644
--- a/libc/src/__support/CPP/type_traits/is_floating_point.h
+++ b/libc/src/__support/CPP/type_traits/is_floating_point.h
@@ -37,7 +37,10 @@ template <typename T> struct is_floating_point {
float128
#endif
,
- bfloat16, fputil::Float128>();
+ bfloat16
+
+ ,
+ fputil::Float128>();
};
template <typename T>
LIBC_INLINE_VAR constexpr bool is_floating_point_v =
diff --git a/libc/src/__support/FPUtil/cast.h b/libc/src/__support/FPUtil/cast.h
index 54c80e862523a..4fc5ea0893ebe 100644
--- a/libc/src/__support/FPUtil/cast.h
+++ b/libc/src/__support/FPUtil/cast.h
@@ -31,7 +31,9 @@ cast(InType x) {
return x;
} else {
if constexpr (cpp::is_same_v<OutType, bfloat16> ||
- cpp::is_same_v<InType, bfloat16>
+ cpp::is_same_v<InType, bfloat16> ||
+ cpp::is_same_v<OutType, Float128> ||
+ cpp::is_same_v<InType, Float128>
#if defined(LIBC_TYPES_HAS_FLOAT16) && !defined(__LIBC_USE_FLOAT16_CONVERSION)
|| cpp::is_same_v<OutType, float16> ||
cpp::is_same_v<InType, float16>
>From 5f6770ff2a60d83c7d3b87c4e5800c8c6544f1e2 Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Tue, 2 Jun 2026 22:24:48 +0530
Subject: [PATCH 6/9] feat: comparison operator overload
---
libc/src/__support/FPUtil/CMakeLists.txt | 2 ++
libc/src/__support/FPUtil/cast.h | 4 ++--
libc/src/__support/FPUtil/dyadic_float.h | 2 +-
libc/src/__support/FPUtil/float128.h | 23 ++++++++++++++++++--
libc/src/__support/macros/properties/types.h | 3 +++
libc/test/src/math/smoke/float128_test.cpp | 8 ++++++-
6 files changed, 36 insertions(+), 6 deletions(-)
diff --git a/libc/src/__support/FPUtil/CMakeLists.txt b/libc/src/__support/FPUtil/CMakeLists.txt
index 20e1c01bb8ca1..c49d873b026e2 100644
--- a/libc/src/__support/FPUtil/CMakeLists.txt
+++ b/libc/src/__support/FPUtil/CMakeLists.txt
@@ -303,6 +303,8 @@ add_header_library(
libc.src.__support.macros.attributes
libc.src.__support.macros.config
libc.src.__support.uint128
+ libc.src.__support.CPP.type_traits
+ .comparison_operations
)
add_subdirectory(generic)
diff --git a/libc/src/__support/FPUtil/cast.h b/libc/src/__support/FPUtil/cast.h
index 4fc5ea0893ebe..e7b2caf92fe4a 100644
--- a/libc/src/__support/FPUtil/cast.h
+++ b/libc/src/__support/FPUtil/cast.h
@@ -32,8 +32,8 @@ cast(InType x) {
} else {
if constexpr (cpp::is_same_v<OutType, bfloat16> ||
cpp::is_same_v<InType, bfloat16> ||
- cpp::is_same_v<OutType, Float128> ||
- cpp::is_same_v<InType, Float128>
+ cpp::is_same_v<OutType, float128> ||
+ cpp::is_same_v<InType, float128>
#if defined(LIBC_TYPES_HAS_FLOAT16) && !defined(__LIBC_USE_FLOAT16_CONVERSION)
|| cpp::is_same_v<OutType, float16> ||
cpp::is_same_v<InType, float16>
diff --git a/libc/src/__support/FPUtil/dyadic_float.h b/libc/src/__support/FPUtil/dyadic_float.h
index 7e4ea2f1a81be..661e3e517f556 100644
--- a/libc/src/__support/FPUtil/dyadic_float.h
+++ b/libc/src/__support/FPUtil/dyadic_float.h
@@ -412,7 +412,7 @@ template <size_t Bits> struct DyadicFloat {
(FPBits<T>::FRACTION_LEN < Bits),
void>>
LIBC_INLINE LIBC_CONSTEXPR_DEFAULT T as() const {
- if constexpr (cpp::is_same_v<T, bfloat16>
+ if constexpr (cpp::is_same_v<T, bfloat16> || cpp::is_same_v<T, float128>
#if defined(LIBC_TYPES_HAS_FLOAT16) && !defined(__LIBC_USE_FLOAT16_CONVERSION)
|| cpp::is_same_v<T, float16>
#endif
diff --git a/libc/src/__support/FPUtil/float128.h b/libc/src/__support/FPUtil/float128.h
index cc72692e8a22f..d887153f58afb 100644
--- a/libc/src/__support/FPUtil/float128.h
+++ b/libc/src/__support/FPUtil/float128.h
@@ -10,6 +10,8 @@
#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_FLOAT128_H
#include "src/__support/CPP/bit.h"
+#include "src/__support/CPP/type_traits.h"
+#include "src/__support/FPUtil/comparison_operations.h"
#include "src/__support/macros/attributes.h"
#include "src/__support/macros/config.h"
#include "src/__support/uint128.h"
@@ -33,10 +35,27 @@ struct Float128 {
}
LIBC_INLINE constexpr bool operator==(Float128 other) const {
- return bits == other.bits;
+ return fputil::equals(*this, other);
}
+
LIBC_INLINE constexpr bool operator!=(Float128 other) const {
- return bits != other.bits;
+ return !fputil::equals(*this, other);
+ }
+
+ LIBC_INLINE constexpr bool operator<(Float128 other) const {
+ return fputil::less_than(*this, other);
+ }
+
+ LIBC_INLINE constexpr bool operator<=(Float128 other) const {
+ return fputil::less_than_or_equals(*this, other);
+ }
+
+ LIBC_INLINE constexpr bool operator>(Float128 other) const {
+ return fputil::greater_than(*this, other);
+ }
+
+ LIBC_INLINE constexpr bool operator>=(Float128 other) const {
+ return fputil::greater_than_or_equals(*this, other);
}
};
diff --git a/libc/src/__support/macros/properties/types.h b/libc/src/__support/macros/properties/types.h
index d94f6068984df..02d08867a4c9f 100644
--- a/libc/src/__support/macros/properties/types.h
+++ b/libc/src/__support/macros/properties/types.h
@@ -66,6 +66,9 @@ struct Float128;
}
} // namespace LIBC_NAMESPACE_DECL
+#ifndef LIBC_TYPES_HAS_FLOAT128
+using float128 = LIBC_NAMESPACE::fputil::Float128;
+#endif // LIBC_TYPES_HAS_FLOAT128
// -- bfloat16 support ---------------------------------------------------------
namespace LIBC_NAMESPACE_DECL {
diff --git a/libc/test/src/math/smoke/float128_test.cpp b/libc/test/src/math/smoke/float128_test.cpp
index 738e5ec703f00..29fcc73384fd5 100644
--- a/libc/test/src/math/smoke/float128_test.cpp
+++ b/libc/test/src/math/smoke/float128_test.cpp
@@ -17,9 +17,15 @@ TEST(LlvmLibcFloat128Test, DefaultConstructor) {
(void)x;
}
-TEST(LlvmLibcFloat128Test, Equality) {
+TEST(LlvmLibcFloat128Test, operators) {
Float128 a(1.0), b(1.0), c(2.0);
+
+ // comparison operators
ASSERT_TRUE(a == b);
ASSERT_TRUE(a != c);
ASSERT_TRUE(b != c);
+ ASSERT_TRUE(c > b);
+ ASSERT_TRUE(a >= b);
+ ASSERT_TRUE(b <= c);
+ ASSERT_TRUE(a < c);
}
>From c080d73e1d4dbc9fd352c064569b83f0ce74181d Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Wed, 3 Jun 2026 00:02:22 +0530
Subject: [PATCH 7/9] marking default const , constexpr
---
libc/src/__support/FPUtil/float128.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libc/src/__support/FPUtil/float128.h b/libc/src/__support/FPUtil/float128.h
index d887153f58afb..c9db7fd683bd1 100644
--- a/libc/src/__support/FPUtil/float128.h
+++ b/libc/src/__support/FPUtil/float128.h
@@ -23,7 +23,7 @@ namespace fputil {
struct Float128 {
UInt128 bits;
- LIBC_INLINE Float128() = default;
+ LIBC_INLINE constexpr Float128() = default;
LIBC_INLINE constexpr explicit Float128(double x) : bits(0) {
uint64_t x_bits = cpp::bit_cast<uint64_t>(x);
>From a38794948f7c924436ba4a9b41a178ef1b85eaec Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Wed, 3 Jun 2026 01:02:42 +0530
Subject: [PATCH 8/9] testing alias + removed constexpr for def const
---
libc/src/__support/FPUtil/cast.h | 4 ++--
libc/src/__support/FPUtil/dyadic_float.h | 2 +-
libc/src/__support/FPUtil/float128.h | 2 +-
libc/src/__support/macros/properties/types.h | 6 +++---
4 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/libc/src/__support/FPUtil/cast.h b/libc/src/__support/FPUtil/cast.h
index e7b2caf92fe4a..4fc5ea0893ebe 100644
--- a/libc/src/__support/FPUtil/cast.h
+++ b/libc/src/__support/FPUtil/cast.h
@@ -32,8 +32,8 @@ cast(InType x) {
} else {
if constexpr (cpp::is_same_v<OutType, bfloat16> ||
cpp::is_same_v<InType, bfloat16> ||
- cpp::is_same_v<OutType, float128> ||
- cpp::is_same_v<InType, float128>
+ cpp::is_same_v<OutType, Float128> ||
+ cpp::is_same_v<InType, Float128>
#if defined(LIBC_TYPES_HAS_FLOAT16) && !defined(__LIBC_USE_FLOAT16_CONVERSION)
|| cpp::is_same_v<OutType, float16> ||
cpp::is_same_v<InType, float16>
diff --git a/libc/src/__support/FPUtil/dyadic_float.h b/libc/src/__support/FPUtil/dyadic_float.h
index 661e3e517f556..3fe427f70b2ab 100644
--- a/libc/src/__support/FPUtil/dyadic_float.h
+++ b/libc/src/__support/FPUtil/dyadic_float.h
@@ -412,7 +412,7 @@ template <size_t Bits> struct DyadicFloat {
(FPBits<T>::FRACTION_LEN < Bits),
void>>
LIBC_INLINE LIBC_CONSTEXPR_DEFAULT T as() const {
- if constexpr (cpp::is_same_v<T, bfloat16> || cpp::is_same_v<T, float128>
+ if constexpr (cpp::is_same_v<T, bfloat16> || cpp::is_same_v<T, Float128>
#if defined(LIBC_TYPES_HAS_FLOAT16) && !defined(__LIBC_USE_FLOAT16_CONVERSION)
|| cpp::is_same_v<T, float16>
#endif
diff --git a/libc/src/__support/FPUtil/float128.h b/libc/src/__support/FPUtil/float128.h
index c9db7fd683bd1..d887153f58afb 100644
--- a/libc/src/__support/FPUtil/float128.h
+++ b/libc/src/__support/FPUtil/float128.h
@@ -23,7 +23,7 @@ namespace fputil {
struct Float128 {
UInt128 bits;
- LIBC_INLINE constexpr Float128() = default;
+ LIBC_INLINE Float128() = default;
LIBC_INLINE constexpr explicit Float128(double x) : bits(0) {
uint64_t x_bits = cpp::bit_cast<uint64_t>(x);
diff --git a/libc/src/__support/macros/properties/types.h b/libc/src/__support/macros/properties/types.h
index 02d08867a4c9f..7b861640c785d 100644
--- a/libc/src/__support/macros/properties/types.h
+++ b/libc/src/__support/macros/properties/types.h
@@ -66,9 +66,9 @@ struct Float128;
}
} // namespace LIBC_NAMESPACE_DECL
-#ifndef LIBC_TYPES_HAS_FLOAT128
-using float128 = LIBC_NAMESPACE::fputil::Float128;
-#endif // LIBC_TYPES_HAS_FLOAT128
+// #ifndef LIBC_TYPES_HAS_FLOAT128
+// using float128 = LIBC_NAMESPACE::fputil::Float128;
+// #endif // LIBC_TYPES_HAS_FLOAT128
// -- bfloat16 support ---------------------------------------------------------
namespace LIBC_NAMESPACE_DECL {
>From 844462a5715eeb29bfd3c298c95420e6f63cd735 Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Wed, 3 Jun 2026 13:40:43 +0530
Subject: [PATCH 9/9] template + LIBC_CONSTEXPR_DEFAULT
---
libc/src/__support/FPUtil/float128.h | 30 ++++++++++++++++------------
1 file changed, 17 insertions(+), 13 deletions(-)
diff --git a/libc/src/__support/FPUtil/float128.h b/libc/src/__support/FPUtil/float128.h
index d887153f58afb..97c0daf79c546 100644
--- a/libc/src/__support/FPUtil/float128.h
+++ b/libc/src/__support/FPUtil/float128.h
@@ -9,8 +9,8 @@
#ifndef LLVM_LIBC_SRC___SUPPORT_FPUTIL_FLOAT128_H
#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_FLOAT128_H
-#include "src/__support/CPP/bit.h"
#include "src/__support/CPP/type_traits.h"
+#include "src/__support/FPUtil/cast.h"
#include "src/__support/FPUtil/comparison_operations.h"
#include "src/__support/macros/attributes.h"
#include "src/__support/macros/config.h"
@@ -25,36 +25,40 @@ struct Float128 {
LIBC_INLINE Float128() = default;
- LIBC_INLINE constexpr explicit Float128(double x) : bits(0) {
- uint64_t x_bits = cpp::bit_cast<uint64_t>(x);
- bits = static_cast<UInt128>(x_bits) << 64U;
+ template <typename T> LIBC_INLINE constexpr explicit Float128(T x) : bits(0) {
+ if constexpr (cpp::is_floating_point_v<T>) {
+ bits = fputil::cast<Float128>(x).bits;
+ }
+ // TODO: add rem after testing
}
- LIBC_INLINE constexpr explicit operator double() const {
- return cpp::bit_cast<double>(static_cast<uint64_t>(bits >> 64U));
+ template <typename T, cpp::enable_if_t<cpp::is_floating_point_v<T> &&
+ !cpp::is_same_v<T, Float128>,
+ int> = 0>
+ LIBC_INLINE LIBC_CONSTEXPR_DEFAULT operator T() const {
+ return fputil::cast<T>(*this);
}
-
- LIBC_INLINE constexpr bool operator==(Float128 other) const {
+ LIBC_INLINE constexpr bool operator==(Float128 &other) const {
return fputil::equals(*this, other);
}
- LIBC_INLINE constexpr bool operator!=(Float128 other) const {
+ LIBC_INLINE constexpr bool operator!=(Float128 &other) const {
return !fputil::equals(*this, other);
}
- LIBC_INLINE constexpr bool operator<(Float128 other) const {
+ LIBC_INLINE constexpr bool operator<(Float128 &other) const {
return fputil::less_than(*this, other);
}
- LIBC_INLINE constexpr bool operator<=(Float128 other) const {
+ LIBC_INLINE constexpr bool operator<=(Float128 &other) const {
return fputil::less_than_or_equals(*this, other);
}
- LIBC_INLINE constexpr bool operator>(Float128 other) const {
+ LIBC_INLINE constexpr bool operator>(Float128 &other) const {
return fputil::greater_than(*this, other);
}
- LIBC_INLINE constexpr bool operator>=(Float128 other) const {
+ LIBC_INLINE constexpr bool operator>=(Float128 &other) const {
return fputil::greater_than_or_equals(*this, other);
}
};
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