[libc-commits] [libc] Modify `truncf128` to use emulated Float128 type (PR #216560)
via libc-commits
libc-commits at lists.llvm.org
Sun Aug 16 04:01:29 PDT 2026
https://github.com/Sukumarsawant created https://github.com/llvm/llvm-project/pull/216560
None
>From e0f631332ca6b00115e30034fef63f9e1fdd7514 Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Sun, 16 Aug 2026 16:28:54 +0530
Subject: [PATCH] intial commit
---
libc/config/baremetal/aarch64/entrypoints.txt | 2 +-
libc/config/baremetal/arm/entrypoints.txt | 2 +-
libc/config/baremetal/riscv/entrypoints.txt | 2 +-
libc/config/darwin/aarch64/entrypoints.txt | 2 +-
libc/config/darwin/x86_64/entrypoints.txt | 1 +
libc/config/freebsd/x86_64/entrypoints.txt | 2 +-
libc/config/gpu/amdgpu/entrypoints.txt | 1 +
libc/config/gpu/nvptx/entrypoints.txt | 1 +
libc/config/linux/aarch64/entrypoints.txt | 2 +-
libc/config/linux/arm/entrypoints.txt | 1 +
libc/config/linux/riscv/entrypoints.txt | 2 +-
libc/config/linux/x86_64/entrypoints.txt | 2 +-
libc/config/windows/entrypoints.txt | 1 +
libc/shared/math/truncf128.h | 6 ------
libc/src/__support/math/CMakeLists.txt | 2 +-
libc/src/__support/math/truncf128.h | 11 ++++-------
libc/src/math/generic/CMakeLists.txt | 1 +
libc/src/math/generic/truncf128.cpp | 5 ++++-
libc/src/math/truncf128.h | 5 +++++
libc/test/shared/shared_math_constexpr_test.cpp | 4 ++--
libc/test/shared/shared_math_test.cpp | 2 +-
libc/test/src/math/smoke/CMakeLists.txt | 1 +
libc/test/src/math/smoke/truncf128_test.cpp | 6 +++++-
23 files changed, 37 insertions(+), 27 deletions(-)
diff --git a/libc/config/baremetal/aarch64/entrypoints.txt b/libc/config/baremetal/aarch64/entrypoints.txt
index 81958d224f70d..890ab9a4d3914 100644
--- a/libc/config/baremetal/aarch64/entrypoints.txt
+++ b/libc/config/baremetal/aarch64/entrypoints.txt
@@ -580,6 +580,7 @@ set(TARGET_LIBM_ENTRYPOINTS
libc.src.math.totalordermagl
libc.src.math.trunc
libc.src.math.truncf
+ libc.src.math.truncf128
libc.src.math.truncl
libc.src.math.ufromfp
libc.src.math.ufromfpf
@@ -793,7 +794,6 @@ if(LIBC_TYPES_HAS_NATIVE_FLOAT128)
libc.src.math.sqrtf128
libc.src.math.totalorderf128
libc.src.math.totalordermagf128
- libc.src.math.truncf128
libc.src.math.ufromfpf128
libc.src.math.ufromfpxf128
)
diff --git a/libc/config/baremetal/arm/entrypoints.txt b/libc/config/baremetal/arm/entrypoints.txt
index ee3ec63132cc2..1431e469fab9d 100644
--- a/libc/config/baremetal/arm/entrypoints.txt
+++ b/libc/config/baremetal/arm/entrypoints.txt
@@ -592,6 +592,7 @@ set(TARGET_LIBM_ENTRYPOINTS
libc.src.math.totalordermagl
libc.src.math.trunc
libc.src.math.truncf
+ libc.src.math.truncf128
libc.src.math.truncl
libc.src.math.ufromfp
libc.src.math.ufromfpf
@@ -804,7 +805,6 @@ if(LIBC_TYPES_HAS_NATIVE_FLOAT128)
libc.src.math.sqrtf128
libc.src.math.totalorderf128
libc.src.math.totalordermagf128
- libc.src.math.truncf128
libc.src.math.ufromfpf128
libc.src.math.ufromfpxf128
)
diff --git a/libc/config/baremetal/riscv/entrypoints.txt b/libc/config/baremetal/riscv/entrypoints.txt
index c9f7c042bf4a8..fb2a622d6a383 100644
--- a/libc/config/baremetal/riscv/entrypoints.txt
+++ b/libc/config/baremetal/riscv/entrypoints.txt
@@ -588,6 +588,7 @@ set(TARGET_LIBM_ENTRYPOINTS
libc.src.math.totalordermagl
libc.src.math.trunc
libc.src.math.truncf
+ libc.src.math.truncf128
libc.src.math.truncl
libc.src.math.ufromfp
libc.src.math.ufromfpf
@@ -801,7 +802,6 @@ if(LIBC_TYPES_HAS_NATIVE_FLOAT128)
libc.src.math.sqrtf128
libc.src.math.totalorderf128
libc.src.math.totalordermagf128
- libc.src.math.truncf128
libc.src.math.ufromfpf128
libc.src.math.ufromfpxf128
)
diff --git a/libc/config/darwin/aarch64/entrypoints.txt b/libc/config/darwin/aarch64/entrypoints.txt
index 0ca00419a916c..d735be3aa05ad 100644
--- a/libc/config/darwin/aarch64/entrypoints.txt
+++ b/libc/config/darwin/aarch64/entrypoints.txt
@@ -400,6 +400,7 @@ set(TARGET_LIBM_ENTRYPOINTS
libc.src.math.totalordermagl
libc.src.math.trunc
libc.src.math.truncf
+ libc.src.math.truncf128
libc.src.math.truncl
libc.src.math.ufromfp
libc.src.math.ufromfpf
@@ -613,7 +614,6 @@ if(LIBC_TYPES_HAS_NATIVE_FLOAT128)
libc.src.math.sqrtf128
libc.src.math.totalorderf128
libc.src.math.totalordermagf128
- libc.src.math.truncf128
libc.src.math.ufromfpf128
libc.src.math.ufromfpxf128
)
diff --git a/libc/config/darwin/x86_64/entrypoints.txt b/libc/config/darwin/x86_64/entrypoints.txt
index 136d5a458d484..c698ad3c57e6a 100644
--- a/libc/config/darwin/x86_64/entrypoints.txt
+++ b/libc/config/darwin/x86_64/entrypoints.txt
@@ -231,6 +231,7 @@ set(TARGET_LIBM_ENTRYPOINTS
#libc.src.math.totalordermagl
#libc.src.math.trunc
#libc.src.math.truncf
+ #libc.src.math.truncf128
#libc.src.math.truncl
)
diff --git a/libc/config/freebsd/x86_64/entrypoints.txt b/libc/config/freebsd/x86_64/entrypoints.txt
index 2223504718444..0e73611fc0ebf 100644
--- a/libc/config/freebsd/x86_64/entrypoints.txt
+++ b/libc/config/freebsd/x86_64/entrypoints.txt
@@ -287,6 +287,7 @@ set(TARGET_LIBM_ENTRYPOINTS
libc.src.math.tanhf
libc.src.math.trunc
libc.src.math.truncf
+ libc.src.math.truncf128
libc.src.math.truncl
)
@@ -551,7 +552,6 @@ if(LIBC_TYPES_HAS_NATIVE_FLOAT128)
libc.src.math.sqrtf128
libc.src.math.totalorderf128
libc.src.math.totalordermagf128
- libc.src.math.truncf128
libc.src.math.ufromfpf128
libc.src.math.ufromfpxf128
)
diff --git a/libc/config/gpu/amdgpu/entrypoints.txt b/libc/config/gpu/amdgpu/entrypoints.txt
index 12783aa4e5316..f55db25157eb7 100644
--- a/libc/config/gpu/amdgpu/entrypoints.txt
+++ b/libc/config/gpu/amdgpu/entrypoints.txt
@@ -526,6 +526,7 @@ set(TARGET_LIBM_ENTRYPOINTS
libc.src.math.totalordermagl
libc.src.math.trunc
libc.src.math.truncf
+ libc.src.math.truncf128
libc.src.math.truncl
libc.src.math.ufromfp
libc.src.math.ufromfpf
diff --git a/libc/config/gpu/nvptx/entrypoints.txt b/libc/config/gpu/nvptx/entrypoints.txt
index 5820448e06663..eb03cef97e05b 100644
--- a/libc/config/gpu/nvptx/entrypoints.txt
+++ b/libc/config/gpu/nvptx/entrypoints.txt
@@ -523,6 +523,7 @@ set(TARGET_LIBM_ENTRYPOINTS
libc.src.math.totalordermagl
libc.src.math.trunc
libc.src.math.truncf
+ libc.src.math.truncf128
libc.src.math.truncl
# FIXME: Broken.
# libc.src.math.ufromfp
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index 071a7830b43d3..694a4e321694c 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -734,6 +734,7 @@ set(TARGET_LIBM_ENTRYPOINTS
libc.src.math.totalordermagl
libc.src.math.trunc
libc.src.math.truncf
+ libc.src.math.truncf128
libc.src.math.truncl
libc.src.math.ufromfp
libc.src.math.ufromfpf
@@ -940,7 +941,6 @@ if(LIBC_TYPES_HAS_NATIVE_FLOAT128)
libc.src.math.sqrtf128
libc.src.math.totalorderf128
libc.src.math.totalordermagf128
- libc.src.math.truncf128
libc.src.math.ufromfpf128
libc.src.math.ufromfpxf128
)
diff --git a/libc/config/linux/arm/entrypoints.txt b/libc/config/linux/arm/entrypoints.txt
index 1adbb04bb4cbe..3c509c1ca090c 100644
--- a/libc/config/linux/arm/entrypoints.txt
+++ b/libc/config/linux/arm/entrypoints.txt
@@ -551,6 +551,7 @@ set(TARGET_LIBM_ENTRYPOINTS
libc.src.math.totalordermagl
libc.src.math.trunc
libc.src.math.truncf
+ libc.src.math.truncf128
libc.src.math.truncl
libc.src.math.ufromfp
libc.src.math.ufromfpf
diff --git a/libc/config/linux/riscv/entrypoints.txt b/libc/config/linux/riscv/entrypoints.txt
index 66dd9dd790737..d67730de4aa39 100644
--- a/libc/config/linux/riscv/entrypoints.txt
+++ b/libc/config/linux/riscv/entrypoints.txt
@@ -807,6 +807,7 @@ set(TARGET_LIBM_ENTRYPOINTS
libc.src.math.totalordermagl
libc.src.math.trunc
libc.src.math.truncf
+ libc.src.math.truncf128
libc.src.math.truncl
libc.src.math.ufromfp
libc.src.math.ufromfpf
@@ -1030,7 +1031,6 @@ if(LIBC_TYPES_HAS_NATIVE_FLOAT128)
libc.src.math.sqrtf128
libc.src.math.totalorderf128
libc.src.math.totalordermagf128
- libc.src.math.truncf128
libc.src.math.ufromfpf128
libc.src.math.ufromfpxf128
)
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 6045886c2f11c..e1c73e4da5da5 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -812,6 +812,7 @@ set(TARGET_LIBM_ENTRYPOINTS
libc.src.math.totalordermagl
libc.src.math.trunc
libc.src.math.truncf
+ libc.src.math.truncf128
libc.src.math.truncl
libc.src.math.ufromfp
libc.src.math.ufromfpf
@@ -1035,7 +1036,6 @@ if(LIBC_TYPES_HAS_NATIVE_FLOAT128)
libc.src.math.sqrtf128
libc.src.math.totalorderf128
libc.src.math.totalordermagf128
- libc.src.math.truncf128
libc.src.math.ufromfpf128
libc.src.math.ufromfpxf128
)
diff --git a/libc/config/windows/entrypoints.txt b/libc/config/windows/entrypoints.txt
index 142b83e71efe6..e59c49ff65cbd 100644
--- a/libc/config/windows/entrypoints.txt
+++ b/libc/config/windows/entrypoints.txt
@@ -321,6 +321,7 @@ set(TARGET_LIBM_ENTRYPOINTS
libc.src.math.tanpif
libc.src.math.trunc
libc.src.math.truncf
+ libc.src.math.truncf128
libc.src.math.truncl
)
diff --git a/libc/shared/math/truncf128.h b/libc/shared/math/truncf128.h
index 0233775d6c6b8..e9de5418e0b30 100644
--- a/libc/shared/math/truncf128.h
+++ b/libc/shared/math/truncf128.h
@@ -9,10 +9,6 @@
#ifndef LLVM_LIBC_SHARED_MATH_TRUNCF128_H
#define LLVM_LIBC_SHARED_MATH_TRUNCF128_H
-#include "include/llvm-libc-types/float128.h"
-
-#ifdef LIBC_TYPES_HAS_NATIVE_FLOAT128
-
#include "shared/libc_common.h"
#include "src/__support/math/truncf128.h"
@@ -24,6 +20,4 @@ using math::truncf128;
} // namespace shared
} // namespace LIBC_NAMESPACE_DECL
-#endif // LIBC_TYPES_HAS_NATIVE_FLOAT128
-
#endif // LLVM_LIBC_SHARED_MATH_TRUNCF128_H
diff --git a/libc/src/__support/math/CMakeLists.txt b/libc/src/__support/math/CMakeLists.txt
index db514db61a9df..28dd8327ba329 100644
--- a/libc/src/__support/math/CMakeLists.txt
+++ b/libc/src/__support/math/CMakeLists.txt
@@ -5703,7 +5703,7 @@ add_header_library(
HDRS
truncf128.h
DEPENDS
- libc.include.llvm-libc-types.float128
+ libc.src.__support.FPUtil.float128
libc.src.__support.FPUtil.nearest_integer_operations
libc.src.__support.macros.config
)
diff --git a/libc/src/__support/math/truncf128.h b/libc/src/__support/math/truncf128.h
index 454b8c1dc2ad5..72e3a100a0935 100644
--- a/libc/src/__support/math/truncf128.h
+++ b/libc/src/__support/math/truncf128.h
@@ -9,23 +9,20 @@
#ifndef LLVM_LIBC_SRC___SUPPORT_MATH_TRUNCF128_H
#define LLVM_LIBC_SRC___SUPPORT_MATH_TRUNCF128_H
-#include "include/llvm-libc-types/float128.h"
-
-#ifdef LIBC_TYPES_HAS_NATIVE_FLOAT128
-
#include "src/__support/FPUtil/NearestIntegerOperations.h"
+#include "src/__support/FPUtil/float128.h"
#include "src/__support/macros/config.h"
namespace LIBC_NAMESPACE_DECL {
namespace math {
-LIBC_INLINE constexpr float128 truncf128(float128 x) {
+using LIBC_NAMESPACE::fputil::Float128;
+
+LIBC_INLINE constexpr Float128 truncf128(Float128 x) {
return fputil::trunc(x);
}
} // namespace math
} // namespace LIBC_NAMESPACE_DECL
-#endif // LIBC_TYPES_HAS_NATIVE_FLOAT128
-
#endif // LLVM_LIBC_SRC___SUPPORT_MATH_TRUNCF128_H
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
index 80c2053066f16..8a3818cbbe591 100644
--- a/libc/src/math/generic/CMakeLists.txt
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -604,6 +604,7 @@ add_entrypoint_object(
HDRS
../truncf128.h
DEPENDS
+ libc.src.__support.CPP.bit
libc.src.__support.math.truncf128
)
diff --git a/libc/src/math/generic/truncf128.cpp b/libc/src/math/generic/truncf128.cpp
index bef079cbbd6a5..083629a6f7a76 100644
--- a/libc/src/math/generic/truncf128.cpp
+++ b/libc/src/math/generic/truncf128.cpp
@@ -7,12 +7,15 @@
//===----------------------------------------------------------------------===//
#include "src/math/truncf128.h"
+#include "src/__support/CPP/bit.h"
#include "src/__support/math/truncf128.h"
namespace LIBC_NAMESPACE_DECL {
+using LIBC_NAMESPACE::fputil::Float128;
+
LLVM_LIBC_FUNCTION(float128, truncf128, (float128 x)) {
- return math::truncf128(x);
+ return cpp::bit_cast<float128>(math::truncf128(cpp::bit_cast<Float128>(x)));
}
} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/math/truncf128.h b/libc/src/math/truncf128.h
index df3899c35e668..265d8cadcdea6 100644
--- a/libc/src/math/truncf128.h
+++ b/libc/src/math/truncf128.h
@@ -9,11 +9,16 @@
#ifndef LLVM_LIBC_SRC_MATH_TRUNCF128_H
#define LLVM_LIBC_SRC_MATH_TRUNCF128_H
+#include "src/__support/FPUtil/float128.h"
#include "src/__support/macros/config.h"
#include "src/__support/macros/properties/types.h"
namespace LIBC_NAMESPACE_DECL {
+#ifndef LIBC_TYPES_HAS_NATIVE_FLOAT128
+using float128 = LIBC_NAMESPACE::fputil::Float128;
+#endif // LIBC_TYPES_HAS_NATIVE_FLOAT128
+
float128 truncf128(float128 x);
} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/test/shared/shared_math_constexpr_test.cpp b/libc/test/shared/shared_math_constexpr_test.cpp
index 6f9df85f3bb1c..721c2d1a5922e 100644
--- a/libc/test/shared/shared_math_constexpr_test.cpp
+++ b/libc/test/shared/shared_math_constexpr_test.cpp
@@ -381,6 +381,8 @@ static_assert(0 == LIBC_NAMESPACE::shared::isnanl(0.0L));
//===----------------------------------------------------------------------===//
static_assert(Float128(0.0) == LIBC_NAMESPACE::shared::ceilf128(Float128(0.0)));
+static_assert(Float128(0.0) ==
+ LIBC_NAMESPACE::shared::truncf128(Float128(0.0)));
//===----------------------------------------------------------------------===//
// Native Float128 Tests
@@ -511,8 +513,6 @@ static_assert(float128(0.0) ==
LIBC_NAMESPACE::shared::roundf128(float128(0.0)));
static_assert(float128(0.0) ==
LIBC_NAMESPACE::shared::roundevenf128(float128(0.0)));
-static_assert(float128(0.0) ==
- LIBC_NAMESPACE::shared::truncf128(float128(0.0)));
#endif // LIBC_TYPES_HAS_NATIVE_FLOAT128
diff --git a/libc/test/shared/shared_math_test.cpp b/libc/test/shared/shared_math_test.cpp
index 8850deda1c805..4861f1a1e1b79 100644
--- a/libc/test/shared/shared_math_test.cpp
+++ b/libc/test/shared/shared_math_test.cpp
@@ -582,6 +582,7 @@ TEST(LlvmLibcSharedMathTest, AllLongDouble) {
// Emulated float128 tests
TEST(LlvmLibcSharedMathTest, AllEmuFloat128) {
EXPECT_FP_EQ(Float128(0.0), LIBC_NAMESPACE::shared::ceilf128(Float128(0.0)));
+ EXPECT_FP_EQ(Float128(0.0), LIBC_NAMESPACE::shared::truncf128(Float128(0.0)));
}
#ifdef LIBC_TYPES_HAS_NATIVE_FLOAT128
@@ -755,7 +756,6 @@ TEST(LlvmLibcSharedMathTest, AllFloat128) {
EXPECT_FP_EQ(float128(0.0), LIBC_NAMESPACE::shared::roundf128(float128(0.0)));
EXPECT_FP_EQ(float128(0.0),
LIBC_NAMESPACE::shared::roundevenf128(float128(0.0)));
- EXPECT_FP_EQ(float128(0.0), LIBC_NAMESPACE::shared::truncf128(float128(0.0)));
}
#endif // LIBC_TYPES_HAS_NATIVE_FLOAT128
diff --git a/libc/test/src/math/smoke/CMakeLists.txt b/libc/test/src/math/smoke/CMakeLists.txt
index 91d76f2c7973c..ec0c43ceaf795 100644
--- a/libc/test/src/math/smoke/CMakeLists.txt
+++ b/libc/test/src/math/smoke/CMakeLists.txt
@@ -363,6 +363,7 @@ add_fp_unittest(
TruncTest.h
DEPENDS
libc.src.math.truncf128
+ libc.src.__support.FPUtil.float128
libc.src.__support.FPUtil.fp_bits
)
diff --git a/libc/test/src/math/smoke/truncf128_test.cpp b/libc/test/src/math/smoke/truncf128_test.cpp
index 7d6487b7d8567..f486213110b6b 100644
--- a/libc/test/src/math/smoke/truncf128_test.cpp
+++ b/libc/test/src/math/smoke/truncf128_test.cpp
@@ -7,7 +7,11 @@
//===----------------------------------------------------------------------===//
#include "TruncTest.h"
-
+#include "src/__support/FPUtil/float128.h"
#include "src/math/truncf128.h"
+#ifndef LIBC_TYPES_HAS_NATIVE_FLOAT128
+using float128 = LIBC_NAMESPACE::fputil::Float128;
+#endif // LIBC_TYPES_HAS_NATIVE_FLOAT128
+
LIST_TRUNC_TESTS(float128, LIBC_NAMESPACE::truncf128)
More information about the libc-commits
mailing list