[libc-commits] [libc] [libc] Remove unnecessary `FPBits` functions and properties (PR #79113)
via libc-commits
libc-commits at lists.llvm.org
Tue Jan 23 02:04:25 PST 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-libc
Author: Guillaume Chatelet (gchatelet)
<details>
<summary>Changes</summary>
This patch reduces the surface of `FPBits`.
---
Patch is 99.21 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/79113.diff
68 Files Affected:
- (modified) libc/fuzzing/stdlib/strtofloat_fuzz.cpp (+1-1)
- (modified) libc/src/__support/FPUtil/DivisionAndRemainderOperations.h (+1-1)
- (modified) libc/src/__support/FPUtil/FPBits.h (+9-42)
- (modified) libc/src/__support/FPUtil/Hypot.h (+2-2)
- (modified) libc/src/__support/FPUtil/ManipulationFunctions.h (+10-14)
- (modified) libc/src/__support/FPUtil/NormalFloat.h (+1-1)
- (modified) libc/src/__support/FPUtil/dyadic_float.h (+1-1)
- (modified) libc/src/__support/FPUtil/except_value_utils.h (+2-4)
- (modified) libc/src/__support/FPUtil/generic/FMA.h (+4-6)
- (modified) libc/src/__support/FPUtil/generic/FMod.h (+1-1)
- (modified) libc/src/__support/FPUtil/generic/sqrt.h (+11-7)
- (modified) libc/src/__support/FPUtil/generic/sqrt_80_bit_long_double.h (+5-3)
- (modified) libc/src/__support/FPUtil/x86_64/NextAfterLongDouble.h (+27-31)
- (modified) libc/src/__support/common.h (-1)
- (modified) libc/src/__support/str_to_float.h (+2-2)
- (modified) libc/src/math/generic/acosf.cpp (+1-1)
- (modified) libc/src/math/generic/acoshf.cpp (+1-1)
- (modified) libc/src/math/generic/asinf.cpp (+1-1)
- (modified) libc/src/math/generic/atanhf.cpp (+2-2)
- (modified) libc/src/math/generic/cosf.cpp (+1-1)
- (modified) libc/src/math/generic/coshf.cpp (+3-3)
- (modified) libc/src/math/generic/exp.cpp (+2-2)
- (modified) libc/src/math/generic/exp10.cpp (+2-2)
- (modified) libc/src/math/generic/exp10f_impl.h (+3-3)
- (modified) libc/src/math/generic/exp2.cpp (+2-2)
- (modified) libc/src/math/generic/exp2f_impl.h (+3-3)
- (modified) libc/src/math/generic/expf.cpp (+2-2)
- (modified) libc/src/math/generic/expm1.cpp (+2-2)
- (modified) libc/src/math/generic/expm1f.cpp (+2-2)
- (modified) libc/src/math/generic/log.cpp (+6-5)
- (modified) libc/src/math/generic/log10.cpp (+6-5)
- (modified) libc/src/math/generic/log10f.cpp (+5-3)
- (modified) libc/src/math/generic/log1p.cpp (+4-3)
- (modified) libc/src/math/generic/log1pf.cpp (+2-2)
- (modified) libc/src/math/generic/log2.cpp (+6-5)
- (modified) libc/src/math/generic/log2f.cpp (+5-3)
- (modified) libc/src/math/generic/logf.cpp (+5-4)
- (modified) libc/src/math/generic/powf.cpp (+7-6)
- (modified) libc/src/math/generic/sincosf.cpp (+3-1)
- (modified) libc/src/math/generic/sinf.cpp (+1-1)
- (modified) libc/src/math/generic/sinhf.cpp (+3-3)
- (modified) libc/src/math/generic/tanf.cpp (+1-1)
- (modified) libc/test/UnitTest/FPMatcher.h (+20-20)
- (modified) libc/test/src/__support/FPUtil/fpbits_test.cpp (+33-48)
- (modified) libc/test/src/math/FDimTest.h (+1-1)
- (modified) libc/test/src/math/FmaTest.h (+21-16)
- (modified) libc/test/src/math/HypotTest.h (+23-20)
- (modified) libc/test/src/math/ILogbTest.h (+11-11)
- (modified) libc/test/src/math/LdExpTest.h (+1-1)
- (modified) libc/test/src/math/NextAfterTest.h (+5-5)
- (modified) libc/test/src/math/RIntTest.h (+12-9)
- (modified) libc/test/src/math/RemQuoTest.h (+14-11)
- (modified) libc/test/src/math/RoundToIntegerTest.h (+13-9)
- (modified) libc/test/src/math/differential_testing/BinaryOpSingleOutputDiff.h (+10-6)
- (modified) libc/test/src/math/differential_testing/SingleInputSingleOutputDiff.h (+4-3)
- (modified) libc/test/src/math/smoke/FDimTest.h (+1-1)
- (modified) libc/test/src/math/smoke/FmaTest.h (+9-7)
- (modified) libc/test/src/math/smoke/HypotTest.h (+10-10)
- (modified) libc/test/src/math/smoke/ILogbTest.h (+9-9)
- (modified) libc/test/src/math/smoke/LdExpTest.h (+1-1)
- (modified) libc/test/src/math/smoke/NextAfterTest.h (+8-6)
- (modified) libc/test/src/math/smoke/NextTowardTest.h (+8-8)
- (modified) libc/test/src/math/smoke/RIntTest.h (+1-1)
- (modified) libc/test/src/math/smoke/RemQuoTest.h (+1-1)
- (modified) libc/test/src/math/smoke/RoundToIntegerTest.h (+13-9)
- (modified) libc/test/src/stdio/sprintf_test.cpp (+21-11)
- (modified) libc/test/src/stdio/sscanf_test.cpp (+13-8)
- (modified) libc/utils/MPFRWrapper/MPFRUtils.cpp (+1-1)
``````````diff
diff --git a/libc/fuzzing/stdlib/strtofloat_fuzz.cpp b/libc/fuzzing/stdlib/strtofloat_fuzz.cpp
index affef6fcf549e0..b773043bda67d8 100644
--- a/libc/fuzzing/stdlib/strtofloat_fuzz.cpp
+++ b/libc/fuzzing/stdlib/strtofloat_fuzz.cpp
@@ -28,7 +28,7 @@ using LIBC_NAMESPACE::fputil::FPBits;
// exponent. Subnormals have a lower effective precision since they don't
// necessarily use all of the bits of the mantissa.
template <typename F> inline constexpr int effective_precision(int exponent) {
- const int full_precision = FPBits<F>::MANTISSA_PRECISION;
+ const int full_precision = FPBits<F>::FRACTION_LEN + 1;
// This is intended to be 0 when the exponent is the lowest normal and
// increase as the exponent's magnitude increases.
diff --git a/libc/src/__support/FPUtil/DivisionAndRemainderOperations.h b/libc/src/__support/FPUtil/DivisionAndRemainderOperations.h
index 1798310c3e31e3..ef9593a42b0055 100644
--- a/libc/src/__support/FPUtil/DivisionAndRemainderOperations.h
+++ b/libc/src/__support/FPUtil/DivisionAndRemainderOperations.h
@@ -31,7 +31,7 @@ LIBC_INLINE T remquo(T x, T y, int &q) {
if (ybits.is_nan())
return y;
if (xbits.is_inf() || ybits.is_zero())
- return FPBits<T>::build_quiet_nan(1);
+ return FPBits<T>::build_quiet_nan(fputil::Sign::POS, 1).get_val();
if (xbits.is_zero()) {
q = 0;
diff --git a/libc/src/__support/FPUtil/FPBits.h b/libc/src/__support/FPUtil/FPBits.h
index 2465158bb2cdfc..0a79b505ecbe1c 100644
--- a/libc/src/__support/FPUtil/FPBits.h
+++ b/libc/src/__support/FPUtil/FPBits.h
@@ -390,7 +390,7 @@ struct FPRepSem : public FPStorage<fp_type> {
return exp_bits() == encode(BiasedExp::BITS_ALL_ZEROES());
}
LIBC_INLINE constexpr bool is_normal() const {
- return is_finite() && !UP::is_subnormal();
+ return is_finite() && !is_subnormal();
}
// Returns the mantissa with the implicit bit set iff the current
// value is a valid normal number.
@@ -556,6 +556,14 @@ struct FPRep : public FPRepSem<fp_type, RetT> {
using UP::FRACTION_MASK;
using UP::SIGN_MASK;
+ // Comparison
+ LIBC_INLINE constexpr friend bool operator==(FPRep a, FPRep b) {
+ return a.uintval() == b.uintval();
+ }
+ LIBC_INLINE constexpr friend bool operator!=(FPRep a, FPRep b) {
+ return a.uintval() != b.uintval();
+ }
+
// Representation
LIBC_INLINE constexpr StorageType uintval() const { return bits & FP_MASK; }
LIBC_INLINE constexpr void set_uintval(StorageType value) {
@@ -698,16 +706,6 @@ struct FPBits final : public internal::FPRep<get_fp_type<T>(), FPBits<T>> {
using UP::bits;
// Constants.
- LIBC_INLINE_VAR static constexpr uint32_t MANTISSA_PRECISION =
- UP::FRACTION_LEN + 1;
- LIBC_INLINE_VAR static constexpr StorageType MIN_NORMAL =
- UP::min_normal(Sign::POS).uintval();
- LIBC_INLINE_VAR static constexpr StorageType MAX_NORMAL =
- UP::max_normal(Sign::POS).uintval();
- LIBC_INLINE_VAR static constexpr StorageType MIN_SUBNORMAL =
- UP::min_subnormal(Sign::POS).uintval();
- LIBC_INLINE_VAR static constexpr StorageType MAX_SUBNORMAL =
- UP::max_subnormal(Sign::POS).uintval();
LIBC_INLINE_VAR static constexpr int MAX_BIASED_EXPONENT =
(1 << UP::EXP_LEN) - 1;
@@ -731,37 +729,6 @@ struct FPBits final : public internal::FPRep<get_fp_type<T>(), FPBits<T>> {
LIBC_INLINE constexpr explicit operator T() const { return get_val(); }
- // Methods below this are used by tests.
- // TODO: inline and remove.
- LIBC_INLINE static constexpr T one(Sign sign = Sign::POS) {
- return T(UP::one(sign));
- }
- LIBC_INLINE static constexpr T zero(Sign sign = Sign::POS) {
- return T(UP::zero(sign));
- }
- LIBC_INLINE static constexpr T inf(Sign sign = Sign::POS) {
- return T(UP::inf(sign));
- }
- LIBC_INLINE static constexpr T min_normal() {
- return T(UP::min_normal(Sign::POS));
- }
- LIBC_INLINE static constexpr T max_normal() {
- return T(UP::max_normal(Sign::POS));
- }
- LIBC_INLINE static constexpr T min_denormal() {
- return T(UP::min_subnormal(Sign::POS));
- }
- LIBC_INLINE static constexpr T max_denormal() {
- return T(UP::max_subnormal(Sign::POS));
- }
- LIBC_INLINE static constexpr T build_nan(StorageType v) {
- return T(UP::build_nan(Sign::POS, v));
- }
- LIBC_INLINE static constexpr T build_quiet_nan(StorageType v,
- Sign sign = Sign::POS) {
- return T(UP::build_quiet_nan(sign, v));
- }
-
// TODO: Use an uint32_t for 'biased_exp'.
LIBC_INLINE static constexpr FPBits<T>
create_value(Sign sign, StorageType biased_exp, StorageType mantissa) {
diff --git a/libc/src/__support/FPUtil/Hypot.h b/libc/src/__support/FPUtil/Hypot.h
index c38a40dfb08984..82237dec09e42e 100644
--- a/libc/src/__support/FPUtil/Hypot.h
+++ b/libc/src/__support/FPUtil/Hypot.h
@@ -197,7 +197,7 @@ LIBC_INLINE T hypot(T x, T y) {
if (int round_mode = quick_get_round();
round_mode == FE_TONEAREST || round_mode == FE_UPWARD)
return T(FPBits_t::inf());
- return T(FPBits_t(FPBits_t::MAX_NORMAL));
+ return T(FPBits_t::max_normal());
}
} else {
// For denormal result, we simply move the leading bit of the result to
@@ -254,7 +254,7 @@ LIBC_INLINE T hypot(T x, T y) {
if (out_exp >= FPBits_t::MAX_BIASED_EXPONENT) {
if (round_mode == FE_TONEAREST || round_mode == FE_UPWARD)
return T(FPBits_t::inf());
- return T(FPBits_t(FPBits_t::MAX_NORMAL));
+ return T(FPBits_t::max_normal());
}
}
diff --git a/libc/src/__support/FPUtil/ManipulationFunctions.h b/libc/src/__support/FPUtil/ManipulationFunctions.h
index 81c8281f3c7bbe..d7114625a9b314 100644
--- a/libc/src/__support/FPUtil/ManipulationFunctions.h
+++ b/libc/src/__support/FPUtil/ManipulationFunctions.h
@@ -108,7 +108,7 @@ LIBC_INLINE T logb(T x) {
return x;
} else if (bits.is_inf()) {
// Return positive infinity.
- return T(FPBits<T>::inf(Sign::POS));
+ return T(FPBits<T>::inf());
}
NormalFloat<T> normal(bits);
@@ -127,7 +127,7 @@ LIBC_INLINE T ldexp(T x, int exp) {
// that adding |exp| to it does not lead to integer rollover. But, if |exp|
// value is larger the exponent range for type T, then we can return infinity
// early. Because the result of the ldexp operation can be a subnormal number,
- // we need to accommodate the (mantissaWidht + 1) worth of shift in
+ // we need to accommodate the (mantissaWidth + 1) worth of shift in
// calculating the limit.
int exp_limit = FPBits<T>::MAX_BIASED_EXPONENT + FPBits<T>::FRACTION_LEN + 1;
if (exp > exp_limit)
@@ -164,26 +164,22 @@ LIBC_INLINE T nextafter(T from, U to) {
return static_cast<T>(to);
using StorageType = typename FPBits<T>::StorageType;
- StorageType int_val = from_bits.uintval();
- if (from != FPBits<T>::zero()) {
- if ((static_cast<U>(from) < to) == (from > FPBits<T>::zero())) {
- ++int_val;
+ if (from != T(0)) {
+ if ((static_cast<U>(from) < to) == (from > T(0))) {
+ from_bits = FPBits<T>(StorageType(from_bits.uintval() + 1));
} else {
- --int_val;
+ from_bits = FPBits<T>(StorageType(from_bits.uintval() - 1));
}
} else {
- int_val = FPBits<T>::MIN_SUBNORMAL;
- if (to_bits.is_neg())
- int_val |= FPBits<T>::SIGN_MASK;
+ from_bits = FPBits<T>::min_subnormal(to_bits.sign());
}
- StorageType exponent_bits = int_val & FPBits<T>::EXP_MASK;
- if (exponent_bits == StorageType(0))
+ if (from_bits.is_subnormal())
raise_except_if_required(FE_UNDERFLOW | FE_INEXACT);
- else if (exponent_bits == FPBits<T>::EXP_MASK)
+ else if (from_bits.is_inf())
raise_except_if_required(FE_OVERFLOW | FE_INEXACT);
- return cpp::bit_cast<T>(int_val);
+ return from_bits.get_val();
}
} // namespace fputil
diff --git a/libc/src/__support/FPUtil/NormalFloat.h b/libc/src/__support/FPUtil/NormalFloat.h
index cfa9e141751055..fa4da33b5b17fa 100644
--- a/libc/src/__support/FPUtil/NormalFloat.h
+++ b/libc/src/__support/FPUtil/NormalFloat.h
@@ -215,7 +215,7 @@ template <> LIBC_INLINE NormalFloat<long double>::operator long double() const {
// Max exponent is of the form 0xFF...E. That is why -2 and not -1.
constexpr int MAX_EXPONENT_VALUE = (1 << LDBits::EXP_LEN) - 2;
if (biased_exponent > MAX_EXPONENT_VALUE) {
- return LDBits::inf(sign);
+ return LDBits::inf(sign).get_val();
}
FPBits<long double> result(0.0l);
diff --git a/libc/src/__support/FPUtil/dyadic_float.h b/libc/src/__support/FPUtil/dyadic_float.h
index 5449f5561d5696..888d7ffec241ea 100644
--- a/libc/src/__support/FPUtil/dyadic_float.h
+++ b/libc/src/__support/FPUtil/dyadic_float.h
@@ -93,7 +93,7 @@ template <size_t Bits> struct DyadicFloat {
return 0.0;
// Assume that it is normalized, and output is also normal.
- constexpr uint32_t PRECISION = FPBits<T>::MANTISSA_PRECISION;
+ constexpr uint32_t PRECISION = FPBits<T>::FRACTION_LEN + 1;
using output_bits_t = typename FPBits<T>::StorageType;
int exp_hi = exponent + static_cast<int>((Bits - 1) + FPBits<T>::EXP_BIAS);
diff --git a/libc/src/__support/FPUtil/except_value_utils.h b/libc/src/__support/FPUtil/except_value_utils.h
index 89849540315f64..1e0381194009d5 100644
--- a/libc/src/__support/FPUtil/except_value_utils.h
+++ b/libc/src/__support/FPUtil/except_value_utils.h
@@ -102,15 +102,13 @@ template <typename T, size_t N> struct ExceptValues {
// Helper functions to set results for exceptional cases.
template <typename T> LIBC_INLINE T round_result_slightly_down(T value_rn) {
volatile T tmp = value_rn;
- const T MIN_NORMAL = FPBits<T>::min_normal();
- tmp = tmp - MIN_NORMAL;
+ tmp -= FPBits<T>::min_normal().get_val();
return tmp;
}
template <typename T> LIBC_INLINE T round_result_slightly_up(T value_rn) {
volatile T tmp = value_rn;
- const T MIN_NORMAL = FPBits<T>::min_normal();
- tmp = tmp + MIN_NORMAL;
+ tmp += FPBits<T>::min_normal().get_val();
return tmp;
}
diff --git a/libc/src/__support/FPUtil/generic/FMA.h b/libc/src/__support/FPUtil/generic/FMA.h
index 6285cac1983d1e..5c36463ea50213 100644
--- a/libc/src/__support/FPUtil/generic/FMA.h
+++ b/libc/src/__support/FPUtil/generic/FMA.h
@@ -130,9 +130,9 @@ template <> LIBC_INLINE double fma<double>(double x, double y, double z) {
return x * y + z;
// Extract mantissa and append hidden leading bits.
- UInt128 x_mant = x_bits.get_mantissa() | FPBits::MIN_NORMAL;
- UInt128 y_mant = y_bits.get_mantissa() | FPBits::MIN_NORMAL;
- UInt128 z_mant = z_bits.get_mantissa() | FPBits::MIN_NORMAL;
+ UInt128 x_mant = x_bits.get_explicit_mantissa();
+ UInt128 y_mant = y_bits.get_explicit_mantissa();
+ UInt128 z_mant = z_bits.get_explicit_mantissa();
// If the exponent of the product x*y > the exponent of z, then no extra
// precision beside the entire product x*y is needed. On the other hand, when
@@ -255,9 +255,7 @@ template <> LIBC_INLINE double fma<double>(double x, double y, double z) {
if ((round_mode == FE_TOWARDZERO) ||
(round_mode == FE_UPWARD && prod_sign.is_neg()) ||
(round_mode == FE_DOWNWARD && prod_sign.is_pos())) {
- result = FPBits::MAX_NORMAL;
- return prod_sign.is_neg() ? -cpp::bit_cast<double>(result)
- : cpp::bit_cast<double>(result);
+ return FPBits::max_normal(prod_sign).get_val();
}
return static_cast<double>(FPBits::inf(prod_sign));
}
diff --git a/libc/src/__support/FPUtil/generic/FMod.h b/libc/src/__support/FPUtil/generic/FMod.h
index f4000b97751efc..18355b801dbc7c 100644
--- a/libc/src/__support/FPUtil/generic/FMod.h
+++ b/libc/src/__support/FPUtil/generic/FMod.h
@@ -124,7 +124,7 @@ template <typename T> struct FModExceptionalInputHandler {
LIBC_INLINE static bool pre_check(T x, T y, T &out) {
using FPB = fputil::FPBits<T>;
- const T quiet_nan = FPB::build_quiet_nan(0);
+ const T quiet_nan = FPB::build_quiet_nan().get_val();
FPB sx(x), sy(y);
if (LIBC_LIKELY(!sy.is_zero() && !sy.is_inf_or_nan() &&
!sx.is_inf_or_nan())) {
diff --git a/libc/src/__support/FPUtil/generic/sqrt.h b/libc/src/__support/FPUtil/generic/sqrt.h
index 21ae9d081d3f12..0a0690ec1463b9 100644
--- a/libc/src/__support/FPUtil/generic/sqrt.h
+++ b/libc/src/__support/FPUtil/generic/sqrt.h
@@ -71,15 +71,19 @@ LIBC_INLINE cpp::enable_if_t<cpp::is_floating_point_v<T>, T> sqrt(T x) {
return x86::sqrt(x);
} else {
// IEEE floating points formats.
- using StorageType = typename FPBits<T>::StorageType;
- constexpr StorageType ONE = StorageType(1) << FPBits<T>::FRACTION_LEN;
+ using Sign = fputil::Sign;
+ using FPBits_t = typename fputil::FPBits<T>;
+ using StorageType = typename FPBits_t::StorageType;
+ constexpr StorageType ONE = StorageType(1) << FPBits_t::FRACTION_LEN;
+ constexpr auto FLT_NAN =
+ FPBits_t::build_quiet_nan(Sign::POS, ONE >> 1).get_val();
- FPBits<T> bits(x);
+ FPBits_t bits(x);
if (bits.is_inf_or_nan()) {
if (bits.is_neg() && (bits.get_mantissa() == 0)) {
// sqrt(-Inf) = NaN
- return FPBits<T>::build_quiet_nan(ONE >> 1);
+ return FLT_NAN;
} else {
// sqrt(NaN) = NaN
// sqrt(+Inf) = +Inf
@@ -91,7 +95,7 @@ LIBC_INLINE cpp::enable_if_t<cpp::is_floating_point_v<T>, T> sqrt(T x) {
return x;
} else if (bits.is_neg()) {
// sqrt( negative numbers ) = NaN
- return FPBits<T>::build_quiet_nan(ONE >> 1);
+ return FLT_NAN;
} else {
int x_exp = bits.get_exponent();
StorageType x_mant = bits.get_mantissa();
@@ -145,10 +149,10 @@ LIBC_INLINE cpp::enable_if_t<cpp::is_floating_point_v<T>, T> sqrt(T x) {
}
// Remove hidden bit and append the exponent field.
- x_exp = ((x_exp >> 1) + FPBits<T>::EXP_BIAS);
+ x_exp = ((x_exp >> 1) + FPBits_t::EXP_BIAS);
y = (y - ONE) |
- (static_cast<StorageType>(x_exp) << FPBits<T>::FRACTION_LEN);
+ (static_cast<StorageType>(x_exp) << FPBits_t::FRACTION_LEN);
switch (quick_get_round()) {
case FE_TONEAREST:
diff --git a/libc/src/__support/FPUtil/generic/sqrt_80_bit_long_double.h b/libc/src/__support/FPUtil/generic/sqrt_80_bit_long_double.h
index 4f8d136938f56e..b0a3776029ca78 100644
--- a/libc/src/__support/FPUtil/generic/sqrt_80_bit_long_double.h
+++ b/libc/src/__support/FPUtil/generic/sqrt_80_bit_long_double.h
@@ -38,14 +38,16 @@ LIBC_INLINE long double sqrt(long double x);
LIBC_INLINE long double sqrt(long double x) {
using LDBits = FPBits<long double>;
using StorageType = typename LDBits::StorageType;
+ using Sign = fputil::Sign;
constexpr StorageType ONE = StorageType(1) << int(LDBits::FRACTION_LEN);
+ constexpr auto LDNAN = LDBits::build_quiet_nan(Sign::POS, ONE >> 1).get_val();
- FPBits<long double> bits(x);
+ LDBits bits(x);
if (bits.is_inf_or_nan()) {
if (bits.is_neg() && (bits.get_mantissa() == 0)) {
// sqrt(-Inf) = NaN
- return LDBits::build_quiet_nan(ONE >> 1);
+ return LDNAN;
} else {
// sqrt(NaN) = NaN
// sqrt(+Inf) = +Inf
@@ -57,7 +59,7 @@ LIBC_INLINE long double sqrt(long double x) {
return x;
} else if (bits.is_neg()) {
// sqrt( negative numbers ) = NaN
- return LDBits::build_quiet_nan(ONE >> 1);
+ return LDNAN;
} else {
int x_exp = bits.get_explicit_exponent();
StorageType x_mant = bits.get_mantissa();
diff --git a/libc/src/__support/FPUtil/x86_64/NextAfterLongDouble.h b/libc/src/__support/FPUtil/x86_64/NextAfterLongDouble.h
index 512f5de4e7931a..d1c76ba954b930 100644
--- a/libc/src/__support/FPUtil/x86_64/NextAfterLongDouble.h
+++ b/libc/src/__support/FPUtil/x86_64/NextAfterLongDouble.h
@@ -43,16 +43,18 @@ LIBC_INLINE long double nextafter(long double from, long double to) {
}
using StorageType = FPBits::StorageType;
- constexpr StorageType SIGN_VAL = (StorageType(1) << 79);
+
constexpr StorageType FRACTION_MASK = FPBits::FRACTION_MASK;
- StorageType int_val = from_bits.uintval();
- if (from < 0.0l) {
- if (from > to) {
- if (int_val == (SIGN_VAL + FPBits::MAX_SUBNORMAL)) {
+ // StorageType int_val = from_bits.uintval();
+ if (from == 0.0l) { // +0.0 / -0.0
+ from_bits = FPBits::min_subnormal(from > to ? Sign::NEG : Sign::POS);
+ } else if (from < 0.0l) {
+ if (to < from) { // toward -inf
+ if (from_bits == FPBits::max_subnormal(Sign::NEG)) {
// We deal with normal/subnormal boundary separately to avoid
// dealing with the implicit bit.
- int_val = SIGN_VAL + FPBits::MIN_NORMAL;
- } else if ((int_val & FRACTION_MASK) == FRACTION_MASK) {
+ from_bits = FPBits::min_normal(Sign::NEG);
+ } else if (from_bits.get_mantissa() == FRACTION_MASK) {
from_bits.set_mantissa(0);
// Incrementing exponent might overflow the value to infinity,
// which is what is expected. Since NaNs are handling separately,
@@ -62,45 +64,40 @@ LIBC_INLINE long double nextafter(long double from, long double to) {
raise_except_if_required(FE_OVERFLOW | FE_INEXACT);
return from_bits.get_val();
} else {
- ++int_val;
+ from_bits = FPBits(StorageType(from_bits.uintval() + 1));
}
- } else {
- if (int_val == (SIGN_VAL + FPBits::MIN_NORMAL)) {
+ } else { // toward +inf
+ if (from_bits == FPBits::min_normal(Sign::NEG)) {
// We deal with normal/subnormal boundary separately to avoid
// dealing with the implicit bit.
- int_val = SIGN_VAL + FPBits::MAX_SUBNORMAL;
- } else if ((int_val & FRACTION_MASK) == 0) {
+ from_bits = FPBits::max_subnormal(Sign::NEG);
+ } else if (from_bits.get_mantissa() == 0) {
from_bits.set_mantissa(FRACTION_MASK);
// from == 0 is handled separately so decrementing the exponent will not
// lead to underflow.
from_bits.set_biased_exponent(from_bits.get_biased_exponent() - 1);
return from_bits.get_val();
} else {
- --int_val;
+ from_bits = FPBits(StorageType(from_bits.uintval() - 1));
}
}
- } else if (from == 0.0l) {
- if (from > to)
- int_val = SIGN_VAL + 1;
- else
- int_val = 1;
} else {
- if (from > to) {
- if (int_val == FPBits::MIN_NORMAL) {
- int_val = FPBits::MAX_SUBNORMAL;
- } else if ((int_val & FRACTION_MASK) == 0) {
+ if (to < from) { // toward -inf
+ if (from_bits == FPBits::min_normal(Sign::POS)) {
+ from_bits = FPBits::max_subnormal(Sign::POS);
+ } else if (from_bits.get_mantissa() == 0) {
from_bits.set_mantissa(FRACTION_MASK);
// from == 0 is handled separately so decrementing the exponent will not
// lead to underflow.
from_bits.set_biased_exponent(from_bits.get_biased_exponent() - 1);
return from_bits.get_val();
} else {
- --int_val;
+ from_bits = FPBits(StorageType(from_bits.uintval() - 1));
}
- } else {
- if (int_val == FPBits::MAX_SUBNORMAL) {
- int_val = FPBits::MIN_NORMAL;
- } else if ((int_val & FRACTION_MASK) == FRACTION_MASK) {
+ } else { // toward +inf
+ if (from_bits == FPBits::max_subnormal(Sign::POS)) {
+ from_bits = FPBits::min_normal(Sign::POS);
+ } else if (from_bits.get_mantissa() == FRACTION_MASK) {
from_bits.set_mantissa(0);
// Incrementing exponent might overflow the value to infinity,
// which is what is expected. Since NaNs are handling separately,
@@ -110,16 +107,15 @@ LIBC_INLINE long double nextafter(long double from, long double to) {
raise_except_if_required(FE_OVERFLOW | FE_INEXACT);
return from_bits.get_val();
} else {
- ++int_val;
+ from_bits = FPBits(StorageType(from_bits.uintval() + 1));
}
}
}
- StorageType implicit_bit = int_val & (StorageType(1) << FPBits::FRACTION_LEN);
- if (implicit_bit == StorageType(0))
+ if (!from_bits.get_implicit_bit())
raise_except_if_required(FE_UNDERFLOW | FE_INEXACT);
- return cpp::bit_cast<long double>(int_val);
+ return from_bits.get_val();
}
} // namespace fputil
diff --git a/libc/src/__support/common.h b/libc/src/__support/common.h
index 53951dc131c28b..a153dfc363d737 100644
--- a/libc/src/__support/common.h
+++ b/libc/src/__support/common.h
@@ -25,7 +25,6 @@
#define LLVM_L...
[truncated]
``````````
</details>
https://github.com/llvm/llvm-project/pull/79113
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