[libc-commits] [libc] efd9dc8 - Revert "[APFloat] Add exp function for APFloat::IEEESsingle using expf implementation from LLVM libc. (#143959)" (#172325)
via libc-commits
libc-commits at lists.llvm.org
Mon Dec 15 07:57:42 PST 2025
Author: Mehdi Amini
Date: 2025-12-15T16:57:37+01:00
New Revision: efd9dc83f26fe1f45277408035ca4b2e31cebee3
URL: https://github.com/llvm/llvm-project/commit/efd9dc83f26fe1f45277408035ca4b2e31cebee3
DIFF: https://github.com/llvm/llvm-project/commit/efd9dc83f26fe1f45277408035ca4b2e31cebee3.diff
LOG: Revert "[APFloat] Add exp function for APFloat::IEEESsingle using expf implementation from LLVM libc. (#143959)" (#172325)
This reverts commit 4190d576823c18f45ee0632baee7d798448178ac.
See https://lab.llvm.org/buildbot/#/builders/181/builds/33524
```
from /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/lib/Support/APFloat.cpp:32:
/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/../libc/src/__support/math/asin_utils.h:548:1: in ‘constexpr’ expansion of ‘__llvm_libc::fputil::DyadicFloat<128>(__llvm_libc::Sign::POS, -127, __llvm_libc::BigInt<128, false, long unsigned int>(__llvm_libc::operator""_u128(((const char*)"0x80000000\'00000000\'00000000\'00000000"))))’
/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/../libc/src/__support/FPUtil/dyadic_float.h:109:5: in ‘constexpr’ expansion of ‘((__llvm_libc::fputil::DyadicFloat<128>*)this)->__llvm_libc::fputil::DyadicFloat<128>::normalize()’
/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/../libc/src/__support/FPUtil/dyadic_float.h:118:16: in ‘constexpr’ expansion of ‘((__llvm_libc::fputil::DyadicFloat<128>*)this)->__llvm_libc::fputil::DyadicFloat<128>::mantissa.__llvm_libc::BigInt<128, false, long unsigned int>::operator<<=(((size_t)shift_length))’
/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/../libc/src/__support/big_int.h:829:52: in ‘constexpr’ expansion of ‘__llvm_libc::multiword::shift<__llvm_libc::multiword::LEFT, false, long unsigned int, 2>(((__llvm_libc::BigInt<128, false, long unsigned int>*)this)->__llvm_libc::BigInt<128, false, long unsigned int>::val, s)’
/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/../libc/src/__support/big_int.h:264:35: error: ‘constexpr __llvm_libc::cpp::enable_if_t<((((sizeof (To) == sizeof (From)) && __llvm_libc::cpp::is_trivially_constructible<To>::value) && __llvm_libc::cpp::is_trivially_copyable<T>::value) && __llvm_libc::cpp::is_trivially_copyable<From>::value), To> __llvm_libc::cpp::bit_cast(const From&) [with To = __int128 unsigned; From = __llvm_libc::cpp::array<long unsigned int, 2>; __llvm_libc::cpp::enable_if_t<((((sizeof (To) == sizeof (From)) && __llvm_libc::cpp::is_trivially_constructible<To>::value) && __llvm_libc::cpp::is_trivially_copyable<T>::value) && __llvm_libc::cpp::is_trivially_copyable<From>::value), To> = __int128 unsigned]’ called in a constant expression
264 | auto tmp = cpp::bit_cast<type>(array);
| ~~~~~~~~~~~~~~~~~~~^~~~~~~
from /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/lib/Support/APFloat.cpp:32:
/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/../libc/src/__support/CPP/bit.h:48:1: note: ‘constexpr __llvm_libc::cpp::enable_if_t<((((sizeof (To) == sizeof (From)) && __llvm_libc::cpp::is_trivially_constructible<To>::value) && __llvm_libc::cpp::is_trivially_copyable<T>::value) && __llvm_libc::cpp::is_trivially_copyable<From>::value), To> __llvm_libc::cpp::bit_cast(const From&) [with To = __int128 unsigned; From = __llvm_libc::cpp::array<long unsigned int, 2>; __llvm_libc::cpp::enable_if_t<((((sizeof (To) == sizeof (From)) && __llvm_libc::cpp::is_trivially_constructible<To>::value) && __llvm_libc::cpp::is_trivially_copyable<T>::value) && __llvm_libc::cpp::is_trivially_copyable<From>::value), To> = __int128 unsigned]’ is not usable as a ‘constexpr’ function because:
48 | bit_cast(const From &from) {
| ^~~~~~~~
/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/../libc/src/__support/CPP/bit.h:56:28: error: call to non-‘constexpr’ function ‘void __llvm_libc::cpp::inline_copy(const char*, char*) [with unsigned int N = 16]’
56 | inline_copy<sizeof(From)>(src, dst);
```
Added:
Modified:
libc/shared/math/expf.h
llvm/CMakeLists.txt
llvm/include/llvm/ADT/APFloat.h
llvm/lib/Support/APFloat.cpp
llvm/lib/Support/CMakeLists.txt
llvm/lib/Target/AMDGPU/AMDGPULibCalls.cpp
llvm/unittests/ADT/APFloatTest.cpp
Removed:
libc/src/__support/math/expf_static_rounding.h
################################################################################
diff --git a/libc/shared/math/expf.h b/libc/shared/math/expf.h
index fbcf49c15ae32..a4e8b0751bb42 100644
--- a/libc/shared/math/expf.h
+++ b/libc/shared/math/expf.h
@@ -11,7 +11,6 @@
#include "shared/libc_common.h"
#include "src/__support/math/expf.h"
-#include "src/__support/math/expf_static_rounding.h"
namespace LIBC_NAMESPACE_DECL {
namespace shared {
diff --git a/libc/src/__support/math/expf_static_rounding.h b/libc/src/__support/math/expf_static_rounding.h
deleted file mode 100644
index fc0b7967adf47..0000000000000
--- a/libc/src/__support/math/expf_static_rounding.h
+++ /dev/null
@@ -1,43 +0,0 @@
-//===-- Implementation header for expf --------------------------*- 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_EXPF_STATIC_ROUNDING_H
-#define LLVM_LIBC_SRC___SUPPORT_MATH_EXPF_STATIC_ROUNDING_H
-
-#include "expf.h"
-#include "src/__support/FPUtil/FEnvImpl.h"
-#include "src/__support/common.h"
-#include "src/__support/macros/config.h"
-
-namespace LIBC_NAMESPACE_DECL {
-
-namespace math {
-
-// Remark: "#pragma STDC FENV_ACCESS" might generate unsupported warnings on
-// certain platforms.
-#pragma STDC FENV_ACCESS ON
-
-// Directional rounding version of expf.
-LIBC_INLINE static float expf(float x, int rounding_mode) {
- int current_rounding_mode = fputil::get_round();
- if (rounding_mode == current_rounding_mode)
- return expf(x);
-
- fputil::set_round(rounding_mode);
- float result = expf(x);
- fputil::set_round(current_rounding_mode);
- return result;
-}
-
-#pragma STDC FENV_ACCESS DEFAULT
-
-} // namespace math
-
-} // namespace LIBC_NAMESPACE_DECL
-
-#endif // LLVM_LIBC_SRC___SUPPORT_MATH_EXPF_STATIC_ROUNDING_H
diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
index 1b402eeb651dd..6d94cbbcd2559 100644
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -657,11 +657,6 @@ endif()
set(LLVM_ENABLE_Z3_SOLVER_DEFAULT "${Z3_FOUND}")
-include(FindLibcCommonUtils)
-if(NOT TARGET llvm-libc-common-utilities)
- message(FATAL_ERROR "LLVM libc is not found at ${libc_path}.")
-endif()
-
if( LLVM_TARGETS_TO_BUILD STREQUAL "all" )
set( LLVM_TARGETS_TO_BUILD ${LLVM_ALL_TARGETS} )
diff --git a/llvm/include/llvm/ADT/APFloat.h b/llvm/include/llvm/ADT/APFloat.h
index e3c461f6a2b55..b2d5ea33f888c 100644
--- a/llvm/include/llvm/ADT/APFloat.h
+++ b/llvm/include/llvm/ADT/APFloat.h
@@ -1493,8 +1493,6 @@ class APFloat : public APFloatBase {
friend APFloat frexp(const APFloat &X, int &Exp, roundingMode RM);
friend IEEEFloat;
friend DoubleAPFloat;
-
- friend APFloat exp(const APFloat &X, roundingMode RM);
};
static_assert(sizeof(APFloat) == sizeof(detail::IEEEFloat),
@@ -1647,10 +1645,6 @@ inline APFloat maximumnum(const APFloat &A, const APFloat &B) {
return A < B ? B : A;
}
-/// Implement IEEE 754-2019 exp functions.
-LLVM_READONLY
-APFloat exp(const APFloat &X, RoundingMode RM = APFloat::rmNearestTiesToEven);
-
inline raw_ostream &operator<<(raw_ostream &OS, const APFloat &V) {
V.print(OS);
return OS;
diff --git a/llvm/lib/Support/APFloat.cpp b/llvm/lib/Support/APFloat.cpp
index e7964e7824a81..e2645fa46bbcd 100644
--- a/llvm/lib/Support/APFloat.cpp
+++ b/llvm/lib/Support/APFloat.cpp
@@ -28,9 +28,6 @@
#include <cstring>
#include <limits.h>
-// Shared headers from LLVM libc
-#include "shared/math.h"
-
#define APFLOAT_DISPATCH_ON_SEMANTICS(METHOD_CALL) \
do { \
if (usesLayout<IEEEFloat>(getSemantics())) \
@@ -6158,29 +6155,6 @@ float APFloat::convertToFloat() const {
return Temp.getIEEE().convertToFloat();
}
-static constexpr int getFEnvRoundingMode(llvm::RoundingMode rm) {
- switch (rm) {
- case APFloat::rmTowardPositive:
- return FE_UPWARD;
- case APFloat::rmTowardNegative:
- return FE_DOWNWARD;
- case APFloat::rmTowardZero:
- return FE_TOWARDZERO;
- default:
- // TODO: fix rmNearestTiesToAway for platform without FE_TONEARESTFROMZERO.
- return FE_TONEAREST;
- };
-}
-
-APFloat exp(const APFloat &X, RoundingMode rounding_mode) {
- if (&X.getSemantics() == &APFloat::IEEEsingle()) {
- float result = LIBC_NAMESPACE::shared::expf(
- X.convertToFloat(), getFEnvRoundingMode(rounding_mode));
- return APFloat(result);
- }
- llvm_unreachable("Unsupported floating-point semantics");
-}
-
APFloat::Storage::~Storage() {
if (usesLayout<IEEEFloat>(*semantics)) {
IEEE.~IEEEFloat();
diff --git a/llvm/lib/Support/CMakeLists.txt b/llvm/lib/Support/CMakeLists.txt
index 5eccf59d81a11..1c397e8c0b766 100644
--- a/llvm/lib/Support/CMakeLists.txt
+++ b/llvm/lib/Support/CMakeLists.txt
@@ -395,9 +395,3 @@ target_include_directories(LLVMSupport
PRIVATE
${LLVM_THIRD_PARTY_DIR}/siphash/include
)
-
-# Integrating LLVM libc's math functions
-target_include_directories(LLVMSupport PRIVATE "${LLVM_SOURCE_DIR}/../libc")
-if(NOT MSVC)
- target_compile_options(LLVMSupport PRIVATE "-Wno-c99-extensions") # _Complex warnings.
-endif()
diff --git a/llvm/lib/Target/AMDGPU/AMDGPULibCalls.cpp b/llvm/lib/Target/AMDGPU/AMDGPULibCalls.cpp
index f83b41773d1a7..821d7f38fcb41 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULibCalls.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULibCalls.cpp
@@ -1531,7 +1531,7 @@ bool AMDGPULibCalls::evaluateScalarMathFunc(const FuncInfo &FInfo, double &Res0,
return true;
case AMDGPULibFunc::EI_EXP:
- Res0 = std::exp(opr0);
+ Res0 = exp(opr0);
return true;
case AMDGPULibFunc::EI_EXP2:
diff --git a/llvm/unittests/ADT/APFloatTest.cpp b/llvm/unittests/ADT/APFloatTest.cpp
index 427cb830c0240..99cc38b6b422b 100644
--- a/llvm/unittests/ADT/APFloatTest.cpp
+++ b/llvm/unittests/ADT/APFloatTest.cpp
@@ -10182,78 +10182,4 @@ TEST(APFloatTest, FrexpQuietSNaN) {
EXPECT_FALSE(Result.isSignaling());
}
-TEST(APFloatTest, expf) {
- std::array<llvm::RoundingMode, 4> allRoundingModes = {
- APFloat::rmNearestTiesToEven, APFloat::rmTowardPositive,
- APFloat::rmTowardNegative, APFloat::rmTowardZero};
- for (auto rm : allRoundingModes) {
- // exp(+-0) = 1 for all rounding modes.
- EXPECT_EQ(1.0f, llvm::exp(APFloat(0.0f), rm).convertToFloat());
- EXPECT_EQ(1.0f, llvm::exp(APFloat(-0.0f), rm).convertToFloat());
- // exp(+Inf) = +Inf for all rounding modes.
- EXPECT_EQ(std::numeric_limits<float>::infinity(),
- llvm::exp(APFloat::getInf(APFloat::IEEEsingle(), false), rm)
- .convertToFloat());
- // exp(-Inf) = 0 for all rounding modes.
- EXPECT_EQ(0.0f, llvm::exp(APFloat::getInf(APFloat::IEEEsingle(), true), rm)
- .convertToFloat());
- // exp(NaN) = NaN for all rounding modes.
- EXPECT_TRUE(llvm::exp(APFloat::getNaN(APFloat::IEEEsingle()), rm).isNaN());
- }
- // exp(1)
- EXPECT_EQ(
- 0x1.5bf0a8p1f,
- llvm::exp(APFloat(1.0f), APFloat::rmNearestTiesToEven).convertToFloat());
- EXPECT_EQ(
- 0x1.5bf0aap1f,
- llvm::exp(APFloat(1.0f), APFloat::rmTowardPositive).convertToFloat());
- EXPECT_EQ(
- 0x1.5bf0a8p1f,
- llvm::exp(APFloat(1.0f), APFloat::rmTowardNegative).convertToFloat());
- EXPECT_EQ(0x1.5bf0a8p1f,
- llvm::exp(APFloat(1.0f), APFloat::rmTowardZero).convertToFloat());
- // exp(float max)
- EXPECT_EQ(std::numeric_limits<float>::infinity(),
- llvm::exp(APFloat::getLargest(APFloat::IEEEsingle(), false),
- APFloat::rmNearestTiesToEven)
- .convertToFloat());
- EXPECT_EQ(std::numeric_limits<float>::infinity(),
- llvm::exp(APFloat::getLargest(APFloat::IEEEsingle(), false),
- APFloat::rmTowardPositive)
- .convertToFloat());
- EXPECT_EQ(std::numeric_limits<float>::max(),
- llvm::exp(APFloat::getLargest(APFloat::IEEEsingle(), false),
- APFloat::rmTowardNegative)
- .convertToFloat());
- EXPECT_EQ(std::numeric_limits<float>::max(),
- llvm::exp(APFloat::getLargest(APFloat::IEEEsingle(), false),
- APFloat::rmTowardZero)
- .convertToFloat());
- // exp(min_denormal)
- EXPECT_EQ(1.0f, llvm::exp(APFloat::getSmallest(APFloat::IEEEsingle(), false),
- APFloat::rmNearestTiesToEven)
- .convertToFloat());
- EXPECT_EQ(0x1.000002p0f,
- llvm::exp(APFloat::getSmallest(APFloat::IEEEsingle(), false),
- APFloat::rmTowardPositive)
- .convertToFloat());
- EXPECT_EQ(1.0f, llvm::exp(APFloat::getSmallest(APFloat::IEEEsingle(), false),
- APFloat::rmTowardNegative)
- .convertToFloat());
- EXPECT_EQ(1.0f, llvm::exp(APFloat::getSmallest(APFloat::IEEEsingle(), false),
- APFloat::rmTowardZero)
- .convertToFloat());
- // Default rounding mode.
- // exp(-1)
- EXPECT_EQ(0x1.78b564p-2f, llvm::exp(APFloat(-1.0f)).convertToFloat());
- EXPECT_EQ(
- 0x1.78b564p-2f,
- llvm::exp(APFloat(-1.0f), APFloat::rmTowardPositive).convertToFloat());
- EXPECT_EQ(
- 0x1.78b562p-2f,
- llvm::exp(APFloat(-1.0f), APFloat::rmTowardNegative).convertToFloat());
- EXPECT_EQ(0x1.78b562p-2f,
- llvm::exp(APFloat(-1.0f), APFloat::rmTowardZero).convertToFloat());
-}
-
} // namespace
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