[libc-commits] [libc] 198238a - [libc][NFC] Remove remaining specializations in FloatProperties (#75165)
via libc-commits
libc-commits at lists.llvm.org
Tue Dec 12 04:06:07 PST 2023
Author: Guillaume Chatelet
Date: 2023-12-12T13:06:02+01:00
New Revision: 198238a598f3b4cfd8cf22e824ff6a3382f5f01e
URL: https://github.com/llvm/llvm-project/commit/198238a598f3b4cfd8cf22e824ff6a3382f5f01e
DIFF: https://github.com/llvm/llvm-project/commit/198238a598f3b4cfd8cf22e824ff6a3382f5f01e.diff
LOG: [libc][NFC] Remove remaining specializations in FloatProperties (#75165)
This patch sinks `EXPLICIT_BIT_MASK` into `get_explicit_mantissa` - the
only function using it. Then it sinks the content of
`FPCommonProperties` directly into `FPProperties`.
Added:
Modified:
libc/src/__support/FPUtil/FloatProperties.h
libc/src/__support/FPUtil/x86_64/LongDoubleBits.h
Removed:
################################################################################
diff --git a/libc/src/__support/FPUtil/FloatProperties.h b/libc/src/__support/FPUtil/FloatProperties.h
index fcc0ed83c16f6f..e72dae60844b80 100644
--- a/libc/src/__support/FPUtil/FloatProperties.h
+++ b/libc/src/__support/FPUtil/FloatProperties.h
@@ -90,13 +90,12 @@ template <typename T, size_t count> static constexpr T mask_trailing_ones() {
return count == 0 ? 0 : ((~T(0)) >> (t_bits - count));
}
-// Derives more properties from 'FPBaseProperties' above.
-// This class serves as a halfway point between 'FPBaseProperties' and
-// 'FPProperties' below.
+} // namespace internal
+
template <FPType fp_type>
-struct FPCommonProperties : private FPBaseProperties<fp_type> {
+struct FPProperties : public internal::FPBaseProperties<fp_type> {
private:
- using UP = FPBaseProperties<fp_type>;
+ using UP = internal::FPBaseProperties<fp_type>;
using UP::EXP_BITS;
using UP::SIG_BITS;
using UP::TOTAL_BITS;
@@ -123,15 +122,15 @@ struct FPCommonProperties : private FPBaseProperties<fp_type> {
// Masks
LIBC_INLINE_VAR static constexpr UIntType SIG_MASK =
- mask_trailing_ones<UIntType, SIG_BITS>() << SIG_MASK_SHIFT;
+ internal::mask_trailing_ones<UIntType, SIG_BITS>() << SIG_MASK_SHIFT;
LIBC_INLINE_VAR static constexpr UIntType EXP_MASK =
- mask_trailing_ones<UIntType, EXP_BITS>() << EXP_MASK_SHIFT;
+ internal::mask_trailing_ones<UIntType, EXP_BITS>() << EXP_MASK_SHIFT;
// Trailing underscore on SIGN_MASK_ is temporary - it will be removed
// once we can replace the public part below with the private one.
LIBC_INLINE_VAR static constexpr UIntType SIGN_MASK_ =
- mask_trailing_ones<UIntType, SIGN_BITS>() << SIGN_MASK_SHIFT;
+ internal::mask_trailing_ones<UIntType, SIGN_BITS>() << SIGN_MASK_SHIFT;
LIBC_INLINE_VAR static constexpr UIntType FP_MASK =
- mask_trailing_ones<UIntType, TOTAL_BITS>();
+ internal::mask_trailing_ones<UIntType, TOTAL_BITS>();
static_assert((SIG_MASK & EXP_MASK & SIGN_MASK_) == 0, "masks disjoint");
static_assert((SIG_MASK | EXP_MASK | SIGN_MASK_) == FP_MASK, "masks cover");
@@ -140,19 +139,19 @@ struct FPCommonProperties : private FPBaseProperties<fp_type> {
}
LIBC_INLINE_VAR static constexpr UIntType QNAN_MASK =
- UP::ENCODING == FPEncoding::X86_ExtendedPrecision
+ UP::ENCODING == internal::FPEncoding::X86_ExtendedPrecision
? bit_at(SIG_BITS - 1) | bit_at(SIG_BITS - 2) // 0b1100...
: bit_at(SIG_BITS - 1); // 0b1000...
LIBC_INLINE_VAR static constexpr UIntType SNAN_MASK =
- UP::ENCODING == FPEncoding::X86_ExtendedPrecision
+ UP::ENCODING == internal::FPEncoding::X86_ExtendedPrecision
? bit_at(SIG_BITS - 1) | bit_at(SIG_BITS - 3) // 0b1010...
: bit_at(SIG_BITS - 2); // 0b0100...
// The number of bits after the decimal dot when the number if in normal form.
LIBC_INLINE_VAR static constexpr int FRACTION_BITS =
- UP::ENCODING == FPEncoding::X86_ExtendedPrecision ? SIG_BITS - 1
- : SIG_BITS;
+ UP::ENCODING == internal::FPEncoding::X86_ExtendedPrecision ? SIG_BITS - 1
+ : SIG_BITS;
public:
// Public facing API to keep the change local to this file.
@@ -163,7 +162,7 @@ struct FPCommonProperties : private FPBaseProperties<fp_type> {
LIBC_INLINE_VAR static constexpr uint32_t MANTISSA_PRECISION =
MANTISSA_WIDTH + 1;
LIBC_INLINE_VAR static constexpr BitsType MANTISSA_MASK =
- mask_trailing_ones<UIntType, MANTISSA_WIDTH>();
+ internal::mask_trailing_ones<UIntType, MANTISSA_WIDTH>();
LIBC_INLINE_VAR static constexpr uint32_t EXPONENT_WIDTH = EXP_BITS;
LIBC_INLINE_VAR static constexpr int32_t EXPONENT_BIAS = EXP_BIAS;
LIBC_INLINE_VAR static constexpr BitsType SIGN_MASK = SIGN_MASK_;
@@ -176,29 +175,6 @@ struct FPCommonProperties : private FPBaseProperties<fp_type> {
static constexpr BitsType QUIET_NAN_MASK = QNAN_MASK;
};
-} // namespace internal
-
-template <FPType fp_type>
-struct FPProperties : public internal::FPCommonProperties<fp_type> {};
-
-// ----------------
-// Work In Progress
-// ----------------
-// The 'FPProperties' template specializations below are being slowly replaced
-// with properties from 'FPCommonProperties' above. Once specializations are
-// empty, 'FPProperties' declaration can be fully replace with
-// 'FPCommonProperties' implementation.
-
-// Properties for numbers represented in 80 bits long double on non-Windows x86
-// platforms.
-template <>
-struct FPProperties<FPType::X86_Binary80>
- : public internal::FPCommonProperties<FPType::X86_Binary80> {
- // The x86 80 bit float represents the leading digit of the mantissa
- // explicitly. This is the mask for that bit.
- static constexpr BitsType EXPLICIT_BIT_MASK = (BitsType(1) << MANTISSA_WIDTH);
-};
-
//-----------------------------------------------------------------------------
template <typename FP> LIBC_INLINE static constexpr FPType get_fp_type() {
if constexpr (cpp::is_same_v<FP, float> && __FLT_MANT_DIG__ == 24)
diff --git a/libc/src/__support/FPUtil/x86_64/LongDoubleBits.h b/libc/src/__support/FPUtil/x86_64/LongDoubleBits.h
index bbc30ff7a376df..60953313a695c5 100644
--- a/libc/src/__support/FPUtil/x86_64/LongDoubleBits.h
+++ b/libc/src/__support/FPUtil/x86_64/LongDoubleBits.h
@@ -68,7 +68,11 @@ template <> struct FPBits<long double> {
}
LIBC_INLINE constexpr UIntType get_explicit_mantissa() const {
- return bits & (FloatProp::MANTISSA_MASK | FloatProp::EXPLICIT_BIT_MASK);
+ // The x86 80 bit float represents the leading digit of the mantissa
+ // explicitly. This is the mask for that bit.
+ constexpr UIntType EXPLICIT_BIT_MASK =
+ (UIntType(1) << FloatProp::MANTISSA_WIDTH);
+ return bits & (FloatProp::MANTISSA_MASK | EXPLICIT_BIT_MASK);
}
LIBC_INLINE constexpr void set_biased_exponent(UIntType expVal) {
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