[libc-commits] [llvm] [libc] Revert "[libc][NFC] Refactor FPBits and remove LongDoubleBits specialization (#78192)" (PR #78329)

Nick Desaulniers via libc-commits libc-commits at lists.llvm.org
Tue Jan 16 11:06:52 PST 2024


https://github.com/nickdesaulniers created https://github.com/llvm/llvm-project/pull/78329

This reverts commit fdbf255c96cb18bc1fb08fa7264446bcbbd5fbd0.

Causes build breakage on 32b arm (see reports:
https://github.com/llvm/llvm-project/pull/78192).

These are reproducible for the 32b arm baremetal target on x86 hosts as well.


>From 351182777f530ab190f96d098e4bd9cc5a7de002 Mon Sep 17 00:00:00 2001
From: Nick Desaulniers <ndesaulniers at google.com>
Date: Tue, 16 Jan 2024 11:04:33 -0800
Subject: [PATCH] Revert "[libc][NFC] Refactor FPBits and remove LongDoubleBits
 specialization (#78192)"

This reverts commit fdbf255c96cb18bc1fb08fa7264446bcbbd5fbd0.

Causes build breakage on 32b arm (see reports:
https://github.com/llvm/llvm-project/pull/78192).

These are reproducible for the 32b arm baremetal target on x86 hosts as well.
---
 libc/src/__support/FPUtil/FPBits.h            | 443 ++++--------------
 .../FPUtil/generic/sqrt_80_bit_long_double.h  |   2 +-
 .../__support/FPUtil/x86_64/LongDoubleBits.h  | 179 +++++++
 .../FPUtil/x86_64/NextAfterLongDouble.h       |   8 +-
 .../test/src/__support/FPUtil/fpbits_test.cpp | 213 ---------
 .../utils/FPUtil/x86_long_double_test.cpp     |  12 +-
 .../llvm-project-overlay/libc/BUILD.bazel     |   1 +
 .../test/src/__support/FPUtil/BUILD.bazel     |  42 --
 8 files changed, 282 insertions(+), 618 deletions(-)
 create mode 100644 libc/src/__support/FPUtil/x86_64/LongDoubleBits.h
 delete mode 100644 utils/bazel/llvm-project-overlay/libc/test/src/__support/FPUtil/BUILD.bazel

diff --git a/libc/src/__support/FPUtil/FPBits.h b/libc/src/__support/FPUtil/FPBits.h
index d6a9f60f71208c..93e32ba7cc9415 100644
--- a/libc/src/__support/FPUtil/FPBits.h
+++ b/libc/src/__support/FPUtil/FPBits.h
@@ -31,40 +31,6 @@ enum class FPType {
   X86_Binary80,
 };
 
-// The classes hierarchy is as follows:
-//
-//             ┌───────────────────┐
-//             │ FPLayout<FPType>  │
-//             └─────────▲─────────┘
-//                       │
-//             ┌─────────┴─────────┐
-//             │ FPRepBase<FPType> │
-//             └─────────▲─────────┘
-//                       │
-//          ┌────────────┴─────────────┐
-//          │                          │
-// ┌────────┴──────┐     ┌─────────────┴──────────────┐
-// │ FPRep<FPType> │     │ FPRep<FPType::X86_Binary80 │
-// └────────▲──────┘     └─────────────▲──────────────┘
-//          │                          │
-//          └────────────┬─────────────┘
-//                       │
-//                 ┌─────┴─────┐
-//                 │ FPBits<T> │
-//                 └───────────┘
-//
-// - 'FPLayout' defines only a few constants, namely the 'StorageType' and the
-// length of the sign, the exponent and significand parts.
-// - 'FPRepBase' builds more constants on top of those from 'FPLayout' like
-// exponent bias, shifts and masks. It also defines tools to assemble or test
-// these parts.
-// - 'FPRep' defines functions to interact with the floating point
-// representation. The default implementation is the one for 'IEEE754', a
-// specialization is provided for X86 Extended Precision that has a different
-// encoding.
-// - 'FPBits' is templated on the platform floating point types. Contrary to
-// 'FPRep' that is platform agnostic 'FPBits' is architecture dependent.
-
 namespace internal {
 
 // Defines the layout (sign, exponent, significand) of a floating point type in
@@ -166,94 +132,11 @@ struct FPRepBase : public internal::FPLayout<fp_type> {
   static_assert((SIG_MASK & EXP_MASK & SIGN_MASK) == 0, "masks disjoint");
   static_assert((SIG_MASK | EXP_MASK | SIGN_MASK) == FP_MASK, "masks cover");
 
-protected:
+private:
   LIBC_INLINE static constexpr StorageType bit_at(int position) {
     return StorageType(1) << position;
   }
 
-  // An opaque type to store a floating point exponent.
-  // We define special values but it is valid to create arbitrary values as long
-  // as they are in the range [MIN, MAX].
-  enum class Exponent : int32_t {
-    MIN = 1 - EXP_BIAS,
-    ZERO = 0,
-    MAX = EXP_BIAS,
-  };
-
-  // An opaque type to store a floating point biased exponent.
-  // We define special values but it is valid to create arbitrary values as long
-  // as they are in the range [BITS_ALL_ZEROES, BITS_ALL_ONES].
-  // Values greater than BITS_ALL_ONES are truncated.
-  enum class BiasedExponent : uint32_t {
-    // The exponent value for denormal numbers.
-    BITS_ALL_ZEROES = 0,
-    // The exponent value for infinity.
-    BITS_ALL_ONES = 2 * EXP_BIAS + 1,
-  };
-
-  LIBC_INLINE static constexpr BiasedExponent biased(Exponent value) {
-    return static_cast<BiasedExponent>(static_cast<int32_t>(value) + EXP_BIAS);
-  }
-
-  // An opaque type to store a floating point significand.
-  // We define special values but it is valid to create arbitrary values as long
-  // as they are in the range [BITS_ALL_ZEROES, BITS_ALL_ONES].
-  // Note that the semantics of the Significand are implementation dependent.
-  // Values greater than BITS_ALL_ONES are truncated.
-  enum class Significand : StorageType {
-    ZERO = 0,
-    LSB = 1,
-    MSB = bit_at(SIG_LEN - 1),
-    // Aliases
-    BITS_ALL_ZEROES = ZERO,
-    BITS_ALL_ONES = SIG_MASK,
-  };
-
-  template <typename T>
-  LIBC_INLINE static constexpr auto storage_cast(T value) {
-    return static_cast<StorageType>(value);
-  }
-
-  LIBC_INLINE friend constexpr Significand operator|(const Significand a,
-                                                     const Significand b) {
-    return Significand{storage_cast(storage_cast(a) | storage_cast(b))};
-  }
-  LIBC_INLINE friend constexpr Significand operator^(const Significand a,
-                                                     const Significand b) {
-    return Significand{storage_cast(storage_cast(a) ^ storage_cast(b))};
-  }
-  LIBC_INLINE friend constexpr Significand operator>>(const Significand a,
-                                                      int shift) {
-    return Significand{storage_cast(storage_cast(a) >> shift)};
-  }
-
-  LIBC_INLINE static constexpr StorageType encode(BiasedExponent exp) {
-    return (storage_cast(exp) << SIG_LEN) & EXP_MASK;
-  }
-
-  LIBC_INLINE static constexpr StorageType encode(Significand value) {
-    return storage_cast(value) & SIG_MASK;
-  }
-
-  LIBC_INLINE static constexpr StorageType encode(BiasedExponent exp,
-                                                  Significand sig) {
-    return encode(exp) | encode(sig);
-  }
-
-  LIBC_INLINE static constexpr StorageType encode(bool sign, BiasedExponent exp,
-                                                  Significand sig) {
-    if (sign)
-      return SIGN_MASK | encode(exp, sig);
-    return encode(exp, sig);
-  }
-
-  LIBC_INLINE constexpr StorageType exp_bits() const { return bits & EXP_MASK; }
-  LIBC_INLINE constexpr StorageType sig_bits() const { return bits & SIG_MASK; }
-  LIBC_INLINE constexpr StorageType exp_sig_bits() const {
-    return bits & EXP_SIG_MASK;
-  }
-
-private:
   // Merge bits from 'a' and 'b' values according to 'mask'.
   // Use 'a' bits when corresponding 'mask' bits are zeroes and 'b' bits when
   // corresponding bits are ones.
@@ -272,6 +155,20 @@ struct FPRepBase : public internal::FPLayout<fp_type> {
   LIBC_INLINE_VAR static constexpr StorageType FRACTION_MASK =
       mask_trailing_ones<StorageType, FRACTION_LEN>();
 
+  // If a number x is a NAN, then it is a quiet NAN if:
+  //   QUIET_NAN_MASK & bits(x) != 0
+  LIBC_INLINE_VAR static constexpr StorageType QUIET_NAN_MASK =
+      fp_type == FPType::X86_Binary80
+          ? bit_at(SIG_LEN - 1) | bit_at(SIG_LEN - 2) // 0b1100...
+          : bit_at(SIG_LEN - 1);                      // 0b1000...
+
+  // Mask to generate a default signaling NAN. Any NAN that is not
+  // a quiet NAN is considered a signaling NAN.
+  LIBC_INLINE_VAR static constexpr StorageType DEFAULT_SIGNALING_NAN =
+      fp_type == FPType::X86_Binary80
+          ? bit_at(SIG_LEN - 1) | bit_at(SIG_LEN - 3) // 0b1010...
+          : bit_at(SIG_LEN - 2);                      // 0b0100...
+
   // The floating point number representation as an unsigned integer.
   StorageType bits = 0;
 
@@ -323,9 +220,6 @@ struct FPRepBase : public internal::FPLayout<fp_type> {
   }
 
   LIBC_INLINE constexpr StorageType uintval() const { return bits & FP_MASK; }
-  LIBC_INLINE constexpr void set_uintval(StorageType value) {
-    bits = (value & FP_MASK);
-  }
 
   LIBC_INLINE constexpr bool is_zero() const {
     return (bits & EXP_SIG_MASK) == 0;
@@ -347,213 +241,6 @@ template <FPType fp_type> struct FPRep : public FPRepBase<fp_type> {
   using UP::FRACTION_LEN;
   using UP::FRACTION_MASK;
   using UP::MANTISSA_PRECISION;
-
-protected:
-  using typename UP::BiasedExponent;
-  using typename UP::Exponent;
-  using typename UP::Significand;
-  using UP::biased;
-  using UP::encode;
-  using UP::exp_bits;
-  using UP::exp_sig_bits;
-  using UP::sig_bits;
-
-public:
-  LIBC_INLINE constexpr bool is_nan() const {
-    return exp_sig_bits() >
-           encode(BiasedExponent::BITS_ALL_ONES, Significand::ZERO);
-  }
-  LIBC_INLINE constexpr bool is_quiet_nan() const {
-    return exp_sig_bits() >=
-           encode(BiasedExponent::BITS_ALL_ONES, Significand::MSB);
-  }
-  LIBC_INLINE constexpr bool is_signaling_nan() const {
-    return is_nan() && !is_quiet_nan();
-  }
-  LIBC_INLINE constexpr bool is_inf() const {
-    return exp_sig_bits() ==
-           encode(BiasedExponent::BITS_ALL_ONES, Significand::ZERO);
-  }
-  LIBC_INLINE constexpr bool is_zero() const {
-    return exp_sig_bits() ==
-           encode(BiasedExponent::BITS_ALL_ZEROES, Significand::ZERO);
-  }
-  LIBC_INLINE constexpr bool is_finite() const {
-    return exp_bits() != encode(BiasedExponent::BITS_ALL_ONES);
-  }
-  LIBC_INLINE
-  constexpr bool is_subnormal() const {
-    return exp_bits() == encode(BiasedExponent::BITS_ALL_ZEROES);
-  }
-  LIBC_INLINE constexpr bool is_normal() const {
-    return is_finite() && !is_subnormal();
-  }
-
-  LIBC_INLINE static constexpr StorageType zero(bool sign = false) {
-    return encode(sign, BiasedExponent::BITS_ALL_ZEROES, Significand::ZERO);
-  }
-  LIBC_INLINE static constexpr StorageType one(bool sign = false) {
-    return encode(sign, biased(Exponent::ZERO), Significand::ZERO);
-  }
-  LIBC_INLINE static constexpr StorageType min_subnormal(bool sign = false) {
-    return encode(sign, BiasedExponent::BITS_ALL_ZEROES, Significand::LSB);
-  }
-  LIBC_INLINE static constexpr StorageType max_subnormal(bool sign = false) {
-    return encode(sign, BiasedExponent::BITS_ALL_ZEROES,
-                  Significand::BITS_ALL_ONES);
-  }
-  LIBC_INLINE static constexpr StorageType min_normal(bool sign = false) {
-    return encode(sign, biased(Exponent::MIN), Significand::ZERO);
-  }
-  LIBC_INLINE static constexpr StorageType max_normal(bool sign = false) {
-    return encode(sign, biased(Exponent::MAX), Significand::BITS_ALL_ONES);
-  }
-  LIBC_INLINE static constexpr StorageType inf(bool sign = false) {
-    return encode(sign, BiasedExponent::BITS_ALL_ONES, Significand::ZERO);
-  }
-  LIBC_INLINE static constexpr StorageType build_nan(bool sign = false,
-                                                     StorageType v = 0) {
-    return encode(sign, BiasedExponent::BITS_ALL_ONES,
-                  (v ? Significand{v} : (Significand::MSB >> 1)));
-  }
-  LIBC_INLINE static constexpr StorageType build_quiet_nan(bool sign = false,
-                                                           StorageType v = 0) {
-    return encode(sign, BiasedExponent::BITS_ALL_ONES,
-                  Significand::MSB | Significand{v});
-  }
-
-  // The function return mantissa with the implicit bit set iff the current
-  // value is a valid normal number.
-  LIBC_INLINE constexpr StorageType get_explicit_mantissa() {
-    if (is_subnormal())
-      return sig_bits();
-    return (StorageType(1) << UP::SIG_LEN) | sig_bits();
-  }
-};
-
-// Specialization for the X86 Extended Precision type.
-template <>
-struct FPRep<FPType::X86_Binary80> : public FPRepBase<FPType::X86_Binary80> {
-  using UP = FPRepBase<FPType::X86_Binary80>;
-  using typename UP::StorageType;
-  using UP::FRACTION_LEN;
-  using UP::FRACTION_MASK;
-  using UP::MANTISSA_PRECISION;
-
-protected:
-  using typename UP::BiasedExponent;
-  using typename UP::Significand;
-  using UP::encode;
-
-public:
-  // The x86 80 bit float represents the leading digit of the mantissa
-  // explicitly. This is the mask for that bit.
-  static constexpr StorageType EXPLICIT_BIT_MASK = StorageType(1)
-                                                   << FRACTION_LEN;
-  // The X80 significand is made of an explicit bit and the fractional part.
-  static_assert((EXPLICIT_BIT_MASK & FRACTION_MASK) == 0,
-                "the explicit bit and the fractional part should not overlap");
-  static_assert((EXPLICIT_BIT_MASK | FRACTION_MASK) == SIG_MASK,
-                "the explicit bit and the fractional part should cover the "
-                "whole significand");
-
-  LIBC_INLINE constexpr bool is_nan() const {
-    // Most encoding forms from the table found in
-    // https://en.wikipedia.org/wiki/Extended_precision#x86_extended_precision_format
-    // are interpreted as NaN.
-    // More precisely :
-    // - Pseudo-Infinity
-    // - Pseudo Not a Number
-    // - Signalling Not a Number
-    // - Floating-point Indefinite
-    // - Quiet Not a Number
-    // - Unnormal
-    // This can be reduced to the following logic:
-    if (exp_bits() == encode(BiasedExponent::BITS_ALL_ONES))
-      return !is_inf();
-    if (exp_bits() != encode(BiasedExponent::BITS_ALL_ZEROES))
-      return (sig_bits() & encode(Significand::MSB)) == 0;
-    return false;
-  }
-  LIBC_INLINE constexpr bool is_quiet_nan() const {
-    return exp_sig_bits() >= encode(BiasedExponent::BITS_ALL_ONES,
-                                    Significand::MSB | (Significand::MSB >> 1));
-  }
-  LIBC_INLINE constexpr bool is_signaling_nan() const {
-    return is_nan() && !is_quiet_nan();
-  }
-  LIBC_INLINE constexpr bool is_inf() const {
-    return exp_sig_bits() ==
-           encode(BiasedExponent::BITS_ALL_ONES, Significand::MSB);
-  }
-  LIBC_INLINE constexpr bool is_zero() const {
-    return exp_sig_bits() ==
-           encode(BiasedExponent::BITS_ALL_ZEROES, Significand::ZERO);
-  }
-  LIBC_INLINE constexpr bool is_finite() const {
-    return !is_inf() && !is_nan();
-  }
-  LIBC_INLINE
-  constexpr bool is_subnormal() const {
-    return exp_sig_bits() >
-           encode(BiasedExponent::BITS_ALL_ZEROES, Significand::ZERO);
-  }
-  LIBC_INLINE constexpr bool is_normal() const {
-    const auto exp = exp_bits();
-    if (exp == encode(BiasedExponent::BITS_ALL_ZEROES) ||
-        exp == encode(BiasedExponent::BITS_ALL_ONES))
-      return false;
-    return get_implicit_bit();
-  }
-
-  LIBC_INLINE static constexpr StorageType zero(bool sign = false) {
-    return encode(sign, BiasedExponent::BITS_ALL_ZEROES, Significand::ZERO);
-  }
-  LIBC_INLINE static constexpr StorageType one(bool sign = false) {
-    return encode(sign, biased(Exponent::ZERO), Significand::MSB);
-  }
-  LIBC_INLINE static constexpr StorageType min_subnormal(bool sign = false) {
-    return encode(sign, BiasedExponent::BITS_ALL_ZEROES, Significand::LSB);
-  }
-  LIBC_INLINE static constexpr StorageType max_subnormal(bool sign = false) {
-    return encode(sign, BiasedExponent::BITS_ALL_ZEROES,
-                  Significand::BITS_ALL_ONES ^ Significand::MSB);
-  }
-  LIBC_INLINE static constexpr StorageType min_normal(bool sign = false) {
-    return encode(sign, biased(Exponent::MIN), Significand::MSB);
-  }
-  LIBC_INLINE static constexpr StorageType max_normal(bool sign = false) {
-    return encode(sign, biased(Exponent::MAX), Significand::BITS_ALL_ONES);
-  }
-  LIBC_INLINE static constexpr StorageType inf(bool sign = false) {
-    return encode(sign, BiasedExponent::BITS_ALL_ONES, Significand::MSB);
-  }
-  LIBC_INLINE static constexpr StorageType build_nan(bool sign = false,
-                                                     StorageType v = 0) {
-    return encode(sign, BiasedExponent::BITS_ALL_ONES,
-                  Significand::MSB |
-                      (v ? Significand{v} : (Significand::MSB >> 2)));
-  }
-  LIBC_INLINE static constexpr StorageType build_quiet_nan(bool sign = false,
-                                                           StorageType v = 0) {
-    return encode(sign, BiasedExponent::BITS_ALL_ONES,
-                  Significand::MSB | (Significand::MSB >> 1) | Significand{v});
-  }
-
-  LIBC_INLINE constexpr StorageType get_explicit_mantissa() const {
-    return sig_bits();
-  }
-
-  // The following functions are specific to FPRep<FPType::X86_Binary80>.
-  // TODO: Remove if possible.
-  LIBC_INLINE constexpr bool get_implicit_bit() const {
-    return bits & EXPLICIT_BIT_MASK;
-  }
-
-  LIBC_INLINE constexpr void set_implicit_bit(bool implicitVal) {
-    if (get_implicit_bit() != implicitVal)
-      bits ^= EXPLICIT_BIT_MASK;
-  }
 };
 
 } // namespace internal
@@ -589,29 +276,47 @@ template <typename T> LIBC_INLINE static constexpr FPType get_fp_type() {
     static_assert(cpp::always_false<UnqualT>, "Unsupported type");
 }
 
-// A generic class to represent floating point formats.
+// A generic class to represent single precision, double precision, and quad
+// precision IEEE 754 floating point formats.
 // On most platforms, the 'float' type corresponds to single precision floating
 // point numbers, the 'double' type corresponds to double precision floating
 // point numers, and the 'long double' type corresponds to the quad precision
 // floating numbers. On x86 platforms however, the 'long double' type maps to
-// an x87 floating point format.
+// an x87 floating point format. This format is an IEEE 754 extension format.
+// It is handled as an explicit specialization of this class.
 template <typename T> struct FPBits : public internal::FPRep<get_fp_type<T>()> {
   static_assert(cpp::is_floating_point_v<T>,
                 "FPBits instantiated with invalid type.");
   using UP = internal::FPRep<get_fp_type<T>()>;
-  using Rep = UP;
-  using StorageType = typename UP::StorageType;
 
+private:
+  using UP::EXP_SIG_MASK;
+  using UP::QUIET_NAN_MASK;
+  using UP::SIG_LEN;
+  using UP::SIG_MASK;
+
+public:
+  using StorageType = typename UP::StorageType;
   using UP::bits;
+  using UP::EXP_BIAS;
   using UP::EXP_LEN;
+  using UP::EXP_MASK;
+  using UP::EXP_MASK_SHIFT;
+  using UP::FRACTION_LEN;
+  using UP::FRACTION_MASK;
+  using UP::SIGN_MASK;
+  using UP::TOTAL_LEN;
   using UP::UP;
 
+  using UP::get_biased_exponent;
+  using UP::is_zero;
   // Constants.
   static constexpr int MAX_BIASED_EXPONENT = (1 << EXP_LEN) - 1;
-  static constexpr StorageType MIN_NORMAL = UP::min_normal(false);
-  static constexpr StorageType MAX_NORMAL = UP::max_normal(false);
-  static constexpr StorageType MIN_SUBNORMAL = UP::min_subnormal(false);
-  static constexpr StorageType MAX_SUBNORMAL = UP::max_subnormal(false);
+  static constexpr StorageType MIN_SUBNORMAL = StorageType(1);
+  static constexpr StorageType MAX_SUBNORMAL = FRACTION_MASK;
+  static constexpr StorageType MIN_NORMAL = (StorageType(1) << FRACTION_LEN);
+  static constexpr StorageType MAX_NORMAL =
+      (StorageType(MAX_BIASED_EXPONENT - 1) << SIG_LEN) | SIG_MASK;
 
   // Constructors.
   LIBC_INLINE constexpr FPBits() = default;
@@ -633,56 +338,88 @@ template <typename T> struct FPBits : public internal::FPRep<get_fp_type<T>()> {
 
   LIBC_INLINE constexpr explicit operator T() const { return get_val(); }
 
-  LIBC_INLINE constexpr bool is_inf_or_nan() const { return !UP::is_finite(); }
+  // The function return mantissa with the implicit bit set iff the current
+  // value is a valid normal number.
+  LIBC_INLINE constexpr StorageType get_explicit_mantissa() {
+    return ((get_biased_exponent() > 0 && !is_inf_or_nan())
+                ? (FRACTION_MASK + 1)
+                : 0) |
+           (FRACTION_MASK & bits);
+  }
+
+  LIBC_INLINE constexpr bool is_inf() const {
+    return (bits & EXP_SIG_MASK) == EXP_MASK;
+  }
+
+  LIBC_INLINE constexpr bool is_nan() const {
+    return (bits & EXP_SIG_MASK) > EXP_MASK;
+  }
+
+  LIBC_INLINE constexpr bool is_quiet_nan() const {
+    return (bits & EXP_SIG_MASK) >= (EXP_MASK | QUIET_NAN_MASK);
+  }
+
+  LIBC_INLINE constexpr bool is_inf_or_nan() const {
+    return (bits & EXP_MASK) == EXP_MASK;
+  }
 
   LIBC_INLINE constexpr FPBits abs() const {
-    return FPBits(bits & UP::EXP_SIG_MASK);
+    return FPBits(bits & EXP_SIG_MASK);
   }
 
   // Methods below this are used by tests.
 
   LIBC_INLINE static constexpr T zero(bool sign = false) {
-    return FPBits(UP::zero(sign)).get_val();
+    StorageType rep = (sign ? SIGN_MASK : StorageType(0)) // sign
+                      | 0                                 // exponent
+                      | 0;                                // mantissa
+    return FPBits(rep).get_val();
   }
 
   LIBC_INLINE static constexpr T neg_zero() { return zero(true); }
 
   LIBC_INLINE static constexpr T inf(bool sign = false) {
-    return FPBits(UP::inf(sign)).get_val();
+    StorageType rep = (sign ? SIGN_MASK : StorageType(0)) // sign
+                      | EXP_MASK                          // exponent
+                      | 0;                                // mantissa
+    return FPBits(rep).get_val();
   }
 
   LIBC_INLINE static constexpr T neg_inf() { return inf(true); }
 
   LIBC_INLINE static constexpr T min_normal() {
-    return FPBits(UP::min_normal(false)).get_val();
+    return FPBits(MIN_NORMAL).get_val();
   }
 
   LIBC_INLINE static constexpr T max_normal() {
-    return FPBits(UP::max_normal(false)).get_val();
+    return FPBits(MAX_NORMAL).get_val();
   }
 
   LIBC_INLINE static constexpr T min_denormal() {
-    return FPBits(UP::min_subnormal(false)).get_val();
+    return FPBits(MIN_SUBNORMAL).get_val();
   }
 
   LIBC_INLINE static constexpr T max_denormal() {
-    return FPBits(UP::max_subnormal(false)).get_val();
+    return FPBits(MAX_SUBNORMAL).get_val();
   }
 
   LIBC_INLINE static constexpr T build_nan(StorageType v) {
-    return FPBits(UP::build_nan(false, v)).get_val();
+    StorageType rep = 0                      // sign
+                      | EXP_MASK             // exponent
+                      | (v & FRACTION_MASK); // mantissa
+    return FPBits(rep).get_val();
   }
 
   LIBC_INLINE static constexpr T build_quiet_nan(StorageType v) {
-    return FPBits(UP::build_quiet_nan(false, v)).get_val();
+    return build_nan(QUIET_NAN_MASK | v);
   }
 
   LIBC_INLINE static constexpr FPBits<T>
   create_value(bool sign, StorageType biased_exp, StorageType mantissa) {
-    static_assert(get_fp_type<T>() != FPType::X86_Binary80,
-                  "This function is not tested for X86 Extended Precision");
-    return FPBits(UP::encode(sign, typename UP::BiasedExponent(biased_exp),
-                             typename UP::Significand(mantissa)));
+    StorageType rep = (sign ? SIGN_MASK : StorageType(0))           // sign
+                      | ((biased_exp << EXP_MASK_SHIFT) & EXP_MASK) // exponent
+                      | (mantissa & FRACTION_MASK);                 // mantissa
+    return FPBits(rep);
   }
 
   // The function convert integer number and unbiased exponent to proper float
@@ -697,8 +434,6 @@ template <typename T> struct FPBits : public internal::FPRep<get_fp_type<T>()> {
   //   5) Number is unsigned, so the result can be only positive.
   LIBC_INLINE static constexpr FPBits<T> make_value(StorageType number,
                                                     int ep) {
-    static_assert(get_fp_type<T>() != FPType::X86_Binary80,
-                  "This function is not tested for X86 Extended Precision");
     FPBits<T> result;
     // offset: +1 for sign, but -1 for implicit first bit
     int lz = cpp::countl_zero(number) - EXP_LEN;
@@ -719,4 +454,8 @@ template <typename T> struct FPBits : public internal::FPRep<get_fp_type<T>()> {
 } // namespace fputil
 } // namespace LIBC_NAMESPACE
 
+#ifdef LIBC_LONG_DOUBLE_IS_X86_FLOAT80
+#include "x86_64/LongDoubleBits.h"
+#endif
+
 #endif // LLVM_LIBC_SRC___SUPPORT_FPUTIL_FPBITS_H
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 8815a18cfbc393..257c02e17d0045 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
@@ -131,7 +131,7 @@ LIBC_INLINE long double sqrt(long double x) {
     out.set_implicit_bit(1);
     out.set_mantissa((y & (ONE - 1)));
 
-    return out.get_val();
+    return out;
   }
 }
 #endif // LIBC_LONG_DOUBLE_IS_X86_FLOAT80
diff --git a/libc/src/__support/FPUtil/x86_64/LongDoubleBits.h b/libc/src/__support/FPUtil/x86_64/LongDoubleBits.h
new file mode 100644
index 00000000000000..c18abcee77ea50
--- /dev/null
+++ b/libc/src/__support/FPUtil/x86_64/LongDoubleBits.h
@@ -0,0 +1,179 @@
+//===-- Bit representation of x86 long double numbers -----------*- 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_X86_64_LONGDOUBLEBITS_H
+#define LLVM_LIBC_SRC___SUPPORT_FPUTIL_X86_64_LONGDOUBLEBITS_H
+
+#include "src/__support/CPP/bit.h"
+#include "src/__support/UInt128.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/attributes.h" // LIBC_INLINE
+#include "src/__support/macros/properties/architectures.h"
+
+#if !defined(LIBC_TARGET_ARCH_IS_X86)
+#error "Invalid include"
+#endif
+
+#include "src/__support/FPUtil/FPBits.h"
+
+#include <stdint.h>
+
+namespace LIBC_NAMESPACE {
+namespace fputil {
+
+template <>
+struct FPBits<long double> : public internal::FPRep<FPType::X86_Binary80> {
+  using UP = internal::FPRep<FPType::X86_Binary80>;
+  using StorageType = typename UP::StorageType;
+
+private:
+  using UP::bits;
+  using UP::EXP_SIG_MASK;
+  using UP::QUIET_NAN_MASK;
+
+public:
+  // Constants.
+  static constexpr int MAX_BIASED_EXPONENT = (1 << EXP_LEN) - 1;
+  // The x86 80 bit float represents the leading digit of the mantissa
+  // explicitly. This is the mask for that bit.
+  static constexpr StorageType EXPLICIT_BIT_MASK = StorageType(1)
+                                                   << FRACTION_LEN;
+  // The X80 significand is made of an explicit bit and the fractional part.
+  static_assert((EXPLICIT_BIT_MASK & FRACTION_MASK) == 0,
+                "the explicit bit and the fractional part should not overlap");
+  static_assert((EXPLICIT_BIT_MASK | FRACTION_MASK) == SIG_MASK,
+                "the explicit bit and the fractional part should cover the "
+                "whole significand");
+  static constexpr StorageType MIN_SUBNORMAL = StorageType(1);
+  // Subnormal numbers include the implicit bit in x86 long double formats.
+  static constexpr StorageType MAX_SUBNORMAL = FRACTION_MASK;
+  static constexpr StorageType MIN_NORMAL =
+      (StorageType(1) << SIG_LEN) | EXPLICIT_BIT_MASK;
+  static constexpr StorageType MAX_NORMAL =
+      (StorageType(MAX_BIASED_EXPONENT - 1) << SIG_LEN) | SIG_MASK;
+
+  // Constructors.
+  LIBC_INLINE constexpr FPBits() = default;
+
+  template <typename XType> LIBC_INLINE constexpr explicit FPBits(XType x) {
+    using Unqual = typename cpp::remove_cv_t<XType>;
+    if constexpr (cpp::is_same_v<Unqual, long double>) {
+      bits = cpp::bit_cast<StorageType>(x);
+    } else if constexpr (cpp::is_same_v<Unqual, StorageType>) {
+      bits = x;
+    } else {
+      // We don't want accidental type promotions/conversions, so we require
+      // exact type match.
+      static_assert(cpp::always_false<XType>);
+    }
+  }
+
+  // Floating-point conversions.
+  LIBC_INLINE constexpr long double get_val() const {
+    return cpp::bit_cast<long double>(bits);
+  }
+
+  LIBC_INLINE constexpr operator long double() const {
+    return cpp::bit_cast<long double>(bits);
+  }
+
+  LIBC_INLINE constexpr StorageType get_explicit_mantissa() const {
+    return bits & SIG_MASK;
+  }
+
+  LIBC_INLINE constexpr bool get_implicit_bit() const {
+    return bits & EXPLICIT_BIT_MASK;
+  }
+
+  LIBC_INLINE constexpr void set_implicit_bit(bool implicitVal) {
+    if (get_implicit_bit() != implicitVal)
+      bits ^= EXPLICIT_BIT_MASK;
+  }
+
+  LIBC_INLINE constexpr bool is_inf() const {
+    return get_biased_exponent() == MAX_BIASED_EXPONENT &&
+           get_mantissa() == 0 && get_implicit_bit() == 1;
+  }
+
+  LIBC_INLINE constexpr bool is_nan() const {
+    if (get_biased_exponent() == MAX_BIASED_EXPONENT) {
+      return (get_implicit_bit() == 0) || get_mantissa() != 0;
+    } else if (get_biased_exponent() != 0) {
+      return get_implicit_bit() == 0;
+    }
+    return false;
+  }
+
+  LIBC_INLINE constexpr bool is_inf_or_nan() const {
+    return (get_biased_exponent() == MAX_BIASED_EXPONENT) ||
+           (get_biased_exponent() != 0 && get_implicit_bit() == 0);
+  }
+
+  LIBC_INLINE constexpr bool is_quiet_nan() const {
+    return (bits & EXP_SIG_MASK) >= (EXP_MASK | QUIET_NAN_MASK);
+  }
+
+  // Methods below this are used by tests.
+
+  LIBC_INLINE static constexpr long double zero(bool sign = false) {
+    StorageType rep = (sign ? SIGN_MASK : StorageType(0)) // sign
+                      | 0                                 // exponent
+                      | 0                                 // explicit bit
+                      | 0;                                // mantissa
+    return FPBits(rep).get_val();
+  }
+
+  LIBC_INLINE static constexpr long double neg_zero() { return zero(true); }
+
+  LIBC_INLINE static constexpr long double inf(bool sign = false) {
+    StorageType rep = (sign ? SIGN_MASK : StorageType(0)) // sign
+                      | EXP_MASK                          // exponent
+                      | EXPLICIT_BIT_MASK                 // explicit bit
+                      | 0;                                // mantissa
+    return FPBits(rep).get_val();
+  }
+
+  LIBC_INLINE static constexpr long double neg_inf() { return inf(true); }
+
+  LIBC_INLINE static constexpr long double min_normal() {
+    return FPBits(MIN_NORMAL).get_val();
+  }
+
+  LIBC_INLINE static constexpr long double max_normal() {
+    return FPBits(MAX_NORMAL).get_val();
+  }
+
+  LIBC_INLINE static constexpr long double min_denormal() {
+    return FPBits(MIN_SUBNORMAL).get_val();
+  }
+
+  LIBC_INLINE static constexpr long double max_denormal() {
+    return FPBits(MAX_SUBNORMAL).get_val();
+  }
+
+  LIBC_INLINE static constexpr long double build_nan(StorageType v) {
+    StorageType rep = 0                      // sign
+                      | EXP_MASK             // exponent
+                      | EXPLICIT_BIT_MASK    // explicit bit
+                      | (v & FRACTION_MASK); // mantissa
+    return FPBits(rep).get_val();
+  }
+
+  LIBC_INLINE static constexpr long double build_quiet_nan(StorageType v) {
+    return build_nan(QUIET_NAN_MASK | v);
+  }
+};
+
+static_assert(
+    sizeof(FPBits<long double>) == sizeof(long double),
+    "Internal long double representation does not match the machine format.");
+
+} // namespace fputil
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC___SUPPORT_FPUTIL_X86_64_LONGDOUBLEBITS_H
diff --git a/libc/src/__support/FPUtil/x86_64/NextAfterLongDouble.h b/libc/src/__support/FPUtil/x86_64/NextAfterLongDouble.h
index 5f15bac5df77f8..b461da3a4c0abc 100644
--- a/libc/src/__support/FPUtil/x86_64/NextAfterLongDouble.h
+++ b/libc/src/__support/FPUtil/x86_64/NextAfterLongDouble.h
@@ -61,7 +61,7 @@ LIBC_INLINE long double nextafter(long double from, long double to) {
         from_bits.set_biased_exponent(from_bits.get_biased_exponent() + 1);
         if (from_bits.is_inf())
           raise_except_if_required(FE_OVERFLOW | FE_INEXACT);
-        return from_bits.get_val();
+        return from_bits;
       } else {
         ++int_val;
       }
@@ -75,7 +75,7 @@ LIBC_INLINE long double nextafter(long double from, long double to) {
         // 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();
+        return from_bits;
       } else {
         --int_val;
       }
@@ -94,7 +94,7 @@ LIBC_INLINE long double nextafter(long double from, long double to) {
         // 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();
+        return from_bits;
       } else {
         --int_val;
       }
@@ -109,7 +109,7 @@ LIBC_INLINE long double nextafter(long double from, long double to) {
         from_bits.set_biased_exponent(from_bits.get_biased_exponent() + 1);
         if (from_bits.is_inf())
           raise_except_if_required(FE_OVERFLOW | FE_INEXACT);
-        return from_bits.get_val();
+        return from_bits;
       } else {
         ++int_val;
       }
diff --git a/libc/test/src/__support/FPUtil/fpbits_test.cpp b/libc/test/src/__support/FPUtil/fpbits_test.cpp
index 3a452f0b7993c4..e2dbe248ef2131 100644
--- a/libc/test/src/__support/FPUtil/fpbits_test.cpp
+++ b/libc/test/src/__support/FPUtil/fpbits_test.cpp
@@ -12,219 +12,6 @@
 
 using LIBC_NAMESPACE::fputil::FPBits;
 
-TEST(LlvmLibcFPBitsTest, FPType_IEEE754_Binary16) {
-  using LIBC_NAMESPACE::fputil::FPType;
-  using LIBC_NAMESPACE::fputil::internal::FPRep;
-  using Rep = FPRep<FPType::IEEE754_Binary16>;
-  using u16 = uint16_t;
-
-  EXPECT_EQ(u16(0b0'00000'0000000000), Rep::zero());
-  EXPECT_EQ(u16(0b0'01111'0000000000), Rep::one());
-  EXPECT_EQ(u16(0b0'00000'0000000001), Rep::min_subnormal());
-  EXPECT_EQ(u16(0b0'00000'1111111111), Rep::max_subnormal());
-  EXPECT_EQ(u16(0b0'00001'0000000000), Rep::min_normal());
-  EXPECT_EQ(u16(0b0'11110'1111111111), Rep::max_normal());
-  EXPECT_EQ(u16(0b0'11111'0000000000), Rep::inf());
-  EXPECT_EQ(u16(0b0'11111'0100000000), Rep::build_nan());
-  EXPECT_EQ(u16(0b0'11111'1000000000), Rep::build_quiet_nan());
-}
-
-TEST(LlvmLibcFPBitsTest, FPType_IEEE754_Binary32) {
-  using LIBC_NAMESPACE::fputil::FPType;
-  using LIBC_NAMESPACE::fputil::internal::FPRep;
-  using Rep = FPRep<FPType::IEEE754_Binary32>;
-  using u32 = uint32_t;
-
-  EXPECT_EQ(u32(0b0'00000000'00000000000000000000000), Rep::zero());
-  EXPECT_EQ(u32(0b0'01111111'00000000000000000000000), Rep::one());
-  EXPECT_EQ(u32(0b0'00000000'00000000000000000000001), Rep::min_subnormal());
-  EXPECT_EQ(u32(0b0'00000000'11111111111111111111111), Rep::max_subnormal());
-  EXPECT_EQ(u32(0b0'00000001'00000000000000000000000), Rep::min_normal());
-  EXPECT_EQ(u32(0b0'11111110'11111111111111111111111), Rep::max_normal());
-  EXPECT_EQ(u32(0b0'11111111'00000000000000000000000), Rep::inf());
-  EXPECT_EQ(u32(0b0'11111111'01000000000000000000000), Rep::build_nan());
-  EXPECT_EQ(u32(0b0'11111111'10000000000000000000000), Rep::build_quiet_nan());
-}
-
-TEST(LlvmLibcFPBitsTest, FPType_IEEE754_Binary64) {
-  using LIBC_NAMESPACE::fputil::FPType;
-  using LIBC_NAMESPACE::fputil::internal::FPRep;
-  using Rep = FPRep<FPType::IEEE754_Binary64>;
-  using u64 = uint64_t;
-
-  EXPECT_EQ(
-      u64(0b0'00000000000'0000000000000000000000000000000000000000000000000000),
-      Rep::zero());
-  EXPECT_EQ(
-      u64(0b0'01111111111'0000000000000000000000000000000000000000000000000000),
-      Rep::one());
-  EXPECT_EQ(
-      u64(0b0'00000000000'0000000000000000000000000000000000000000000000000001),
-      Rep::min_subnormal());
-  EXPECT_EQ(
-      u64(0b0'00000000000'1111111111111111111111111111111111111111111111111111),
-      Rep::max_subnormal());
-  EXPECT_EQ(
-      u64(0b0'00000000001'0000000000000000000000000000000000000000000000000000),
-      Rep::min_normal());
-  EXPECT_EQ(
-      u64(0b0'11111111110'1111111111111111111111111111111111111111111111111111),
-      Rep::max_normal());
-  EXPECT_EQ(
-      u64(0b0'11111111111'0000000000000000000000000000000000000000000000000000),
-      Rep::inf());
-  EXPECT_EQ(
-      u64(0b0'11111111111'0100000000000000000000000000000000000000000000000000),
-      Rep::build_nan());
-  EXPECT_EQ(
-      u64(0b0'11111111111'1000000000000000000000000000000000000000000000000000),
-      Rep::build_quiet_nan());
-}
-
-static constexpr UInt128 u128(uint64_t hi, uint64_t lo) {
-#if defined(__SIZEOF_INT128__)
-  return __uint128_t(hi) << 64 | __uint128_t(lo);
-#else
-  return UInt128({hi, lo});
-#endif
-}
-
-TEST(LlvmLibcFPBitsTest, FPType_X86_Binary80) {
-  using LIBC_NAMESPACE::fputil::FPType;
-  using LIBC_NAMESPACE::fputil::internal::FPRep;
-  using Rep = FPRep<FPType::X86_Binary80>;
-
-  EXPECT_EQ(
-      u128(0b0'000000000000000,
-           0b0000000000000000000000000000000000000000000000000000000000000000),
-      Rep::zero());
-  EXPECT_EQ(
-      u128(0b0'011111111111111,
-           0b1000000000000000000000000000000000000000000000000000000000000000),
-      Rep::one());
-  EXPECT_EQ(
-      u128(0b0'000000000000000,
-           0b0000000000000000000000000000000000000000000000000000000000000001),
-      Rep::min_subnormal());
-  EXPECT_EQ(
-      u128(0b0'000000000000000,
-           0b0111111111111111111111111111111111111111111111111111111111111111),
-      Rep::max_subnormal());
-  EXPECT_EQ(
-      u128(0b0'000000000000001,
-           0b1000000000000000000000000000000000000000000000000000000000000000),
-      Rep::min_normal());
-  EXPECT_EQ(
-      u128(0b0'111111111111110,
-           0b1111111111111111111111111111111111111111111111111111111111111111),
-      Rep::max_normal());
-  EXPECT_EQ(
-      u128(0b0'111111111111111,
-           0b1000000000000000000000000000000000000000000000000000000000000000),
-      Rep::inf());
-  EXPECT_EQ(
-      u128(0b0'111111111111111,
-           0b1010000000000000000000000000000000000000000000000000000000000000),
-      Rep::build_nan());
-  EXPECT_EQ(
-      u128(0b0'111111111111111,
-           0b1100000000000000000000000000000000000000000000000000000000000000),
-      Rep::build_quiet_nan());
-}
-
-TEST(LlvmLibcFPBitsTest, FPType_X86_Binary80_IsNan) {
-  using LIBC_NAMESPACE::fputil::FPType;
-  using LIBC_NAMESPACE::fputil::internal::FPRep;
-  using Rep = FPRep<FPType::X86_Binary80>;
-
-  const auto is_nan = [](uint64_t hi, uint64_t lo) {
-    Rep rep;
-    rep.set_uintval(u128(hi, lo));
-    return rep.is_nan();
-  };
-
-  EXPECT_TRUE(is_nan(
-      0b0'111111111111111, // NAN : Pseudo-Infinity
-      0b0000000000000000000000000000000000000000000000000000000000000000));
-  EXPECT_TRUE(is_nan(
-      0b0'111111111111111, // NAN : Pseudo Not a Number
-      0b0000000000000000000000000000000000000000000000000000000000000001));
-  EXPECT_TRUE(is_nan(
-      0b0'111111111111111, // NAN : Pseudo Not a Number
-      0b0100000000000000000000000000000000000000000000000000000000000000));
-  EXPECT_TRUE(is_nan(
-      0b0'111111111111111, // NAN : Signalling Not a Number
-      0b1000000000000000000000000000000000000000000000000000000000000001));
-  EXPECT_TRUE(is_nan(
-      0b0'111111111111111, // NAN : Floating-point Indefinite
-      0b1100000000000000000000000000000000000000000000000000000000000000));
-  EXPECT_TRUE(is_nan(
-      0b0'111111111111111, // NAN : Quiet Not a Number
-      0b1100000000000000000000000000000000000000000000000000000000000001));
-  EXPECT_TRUE(is_nan(
-      0b0'111111111111110, // NAN : Unnormal
-      0b0000000000000000000000000000000000000000000000000000000000000000));
-
-  EXPECT_FALSE(is_nan(
-      0b0'000000000000000, // Zero
-      0b0000000000000000000000000000000000000000000000000000000000000000));
-  EXPECT_FALSE(is_nan(
-      0b0'000000000000000, // Subnormal
-      0b0000000000000000000000000000000000000000000000000000000000000001));
-  EXPECT_FALSE(is_nan(
-      0b0'000000000000000, // Pseudo Denormal
-      0b1000000000000000000000000000000000000000000000000000000000000001));
-  EXPECT_FALSE(is_nan(
-      0b0'111111111111111, // Infinity
-      0b1000000000000000000000000000000000000000000000000000000000000000));
-  EXPECT_FALSE(is_nan(
-      0b0'111111111111110, // Normalized
-      0b1000000000000000000000000000000000000000000000000000000000000000));
-}
-
-TEST(LlvmLibcFPBitsTest, FPType_IEEE754_Binary128) {
-  using LIBC_NAMESPACE::fputil::FPType;
-  using LIBC_NAMESPACE::fputil::internal::FPRep;
-  using Rep = FPRep<FPType::IEEE754_Binary128>;
-
-  EXPECT_EQ(
-      u128(0b0'000000000000000'000000000000000000000000000000000000000000000000,
-           0b0000000000000000000000000000000000000000000000000000000000000000),
-      Rep::zero());
-  EXPECT_EQ(
-      u128(0b0'011111111111111'000000000000000000000000000000000000000000000000,
-           0b0000000000000000000000000000000000000000000000000000000000000000),
-      Rep::one());
-  EXPECT_EQ(
-      u128(0b0'000000000000000'000000000000000000000000000000000000000000000000,
-           0b0000000000000000000000000000000000000000000000000000000000000001),
-      Rep::min_subnormal());
-  EXPECT_EQ(
-      u128(0b0'000000000000000'111111111111111111111111111111111111111111111111,
-           0b1111111111111111111111111111111111111111111111111111111111111111),
-      Rep::max_subnormal());
-  EXPECT_EQ(
-      u128(0b0'000000000000001'000000000000000000000000000000000000000000000000,
-           0b0000000000000000000000000000000000000000000000000000000000000000),
-      Rep::min_normal());
-  EXPECT_EQ(
-      u128(0b0'111111111111110'111111111111111111111111111111111111111111111111,
-           0b1111111111111111111111111111111111111111111111111111111111111111),
-      Rep::max_normal());
-  EXPECT_EQ(
-      u128(0b0'111111111111111'000000000000000000000000000000000000000000000000,
-           0b0000000000000000000000000000000000000000000000000000000000000000),
-      Rep::inf());
-  EXPECT_EQ(
-      u128(0b0'111111111111111'010000000000000000000000000000000000000000000000,
-           0b0000000000000000000000000000000000000000000000000000000000000000),
-      Rep::build_nan());
-  EXPECT_EQ(
-      u128(0b0'111111111111111'100000000000000000000000000000000000000000000000,
-           0b0000000000000000000000000000000000000000000000000000000000000000),
-      Rep::build_quiet_nan());
-}
-
 TEST(LlvmLibcFPBitsTest, FloatType) {
   using FloatBits = FPBits<float>;
 
diff --git a/libc/test/utils/FPUtil/x86_long_double_test.cpp b/libc/test/utils/FPUtil/x86_long_double_test.cpp
index bafbbe2a410759..7da835fc95fc92 100644
--- a/libc/test/utils/FPUtil/x86_long_double_test.cpp
+++ b/libc/test/utils/FPUtil/x86_long_double_test.cpp
@@ -27,7 +27,7 @@ TEST(LlvmLibcX86LongDoubleTest, is_nan) {
     // If exponent has the max value and the implicit bit is 0,
     // then the number is a NaN for all values of mantissa.
     bits.set_mantissa(i);
-    long double nan = bits.get_val();
+    long double nan = bits;
     ASSERT_NE(static_cast<int>(isnan(nan)), 0);
     ASSERT_TRUE(bits.is_nan());
   }
@@ -38,7 +38,7 @@ TEST(LlvmLibcX86LongDoubleTest, is_nan) {
     // then the number is a NaN for all non-zero values of mantissa.
     // Note the initial value of |i| of 1 to avoid a zero mantissa.
     bits.set_mantissa(i);
-    long double nan = bits.get_val();
+    long double nan = bits;
     ASSERT_NE(static_cast<int>(isnan(nan)), 0);
     ASSERT_TRUE(bits.is_nan());
   }
@@ -49,7 +49,7 @@ TEST(LlvmLibcX86LongDoubleTest, is_nan) {
     // If exponent is non-zero and also not max, and the implicit bit is 0,
     // then the number is a NaN for all values of mantissa.
     bits.set_mantissa(i);
-    long double nan = bits.get_val();
+    long double nan = bits;
     ASSERT_NE(static_cast<int>(isnan(nan)), 0);
     ASSERT_TRUE(bits.is_nan());
   }
@@ -60,7 +60,7 @@ TEST(LlvmLibcX86LongDoubleTest, is_nan) {
     // If exponent is non-zero and also not max, and the implicit bit is 1,
     // then the number is normal value for all values of mantissa.
     bits.set_mantissa(i);
-    long double valid = bits.get_val();
+    long double valid = bits;
     ASSERT_EQ(static_cast<int>(isnan(valid)), 0);
     ASSERT_FALSE(bits.is_nan());
   }
@@ -70,7 +70,7 @@ TEST(LlvmLibcX86LongDoubleTest, is_nan) {
   for (unsigned int i = 0; i < COUNT; ++i) {
     // If exponent is zero, then the number is a valid but denormal value.
     bits.set_mantissa(i);
-    long double valid = bits.get_val();
+    long double valid = bits;
     ASSERT_EQ(static_cast<int>(isnan(valid)), 0);
     ASSERT_FALSE(bits.is_nan());
   }
@@ -80,7 +80,7 @@ TEST(LlvmLibcX86LongDoubleTest, is_nan) {
   for (unsigned int i = 0; i < COUNT; ++i) {
     // If exponent is zero, then the number is a valid but denormal value.
     bits.set_mantissa(i);
-    long double valid = bits.get_val();
+    long double valid = bits;
     ASSERT_EQ(static_cast<int>(isnan(valid)), 0);
     ASSERT_FALSE(bits.is_nan());
   }
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index 6fa47c0090b87a..f222831eefd762 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -662,6 +662,7 @@ libc_support_library(
 libc_support_library(
     name = "__support_fputil_fp_bits",
     hdrs = ["src/__support/FPUtil/FPBits.h"],
+    textual_hdrs = ["src/__support/FPUtil/x86_64/LongDoubleBits.h"],
     deps = [
         ":__support_common",
         ":__support_cpp_bit",
diff --git a/utils/bazel/llvm-project-overlay/libc/test/src/__support/FPUtil/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/test/src/__support/FPUtil/BUILD.bazel
deleted file mode 100644
index 4f206b21e478b1..00000000000000
--- a/utils/bazel/llvm-project-overlay/libc/test/src/__support/FPUtil/BUILD.bazel
+++ /dev/null
@@ -1,42 +0,0 @@
-# This file is licensed 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
-
-# Tests for LLVM libc __support functions.
-
-load("//libc/test:libc_test_rules.bzl", "libc_test")
-
-package(default_visibility = ["//visibility:public"])
-
-licenses(["notice"])
-
-libc_test(
-    name = "fpbits_test",
-    srcs = ["fpbits_test.cpp"],
-    deps = [
-        "//libc:__support_fputil_fp_bits",
-        "//libc:__support_fputil_fpbits_str",
-    ],
-)
-
-libc_test(
-    name = "dyadic_float_test",
-    srcs = ["dyadic_float_test.cpp"],
-    deps = [
-        "//libc:__support_fputil_dyadic_float",
-        "//libc:__support_uint",
-        "//libc:__support_uint128",
-        "//libc/test/UnitTest:fp_test_helpers",
-        "//libc/utils/MPFRWrapper:mpfr_wrapper",
-    ],
-)
-
-libc_test(
-    name = "rounding_mode_test",
-    srcs = ["rounding_mode_test.cpp"],
-    deps = [
-        "//libc:__support_fputil_rounding_mode",
-        "//libc:__support_uint128",
-        "//libc/utils/MPFRWrapper:mpfr_wrapper",
-    ],
-)



More information about the libc-commits mailing list