diff options
| author | Trevor Gross <tmgross@umich.edu> | 2024-12-09 09:25:22 +0000 |
|---|---|---|
| committer | Trevor Gross <tmgross@umich.edu> | 2025-03-02 07:08:01 +0000 |
| commit | 6c34daff57101922dc97e1860bf5940ea88d3906 (patch) | |
| tree | 9e537cbb65b8dc625192b6e0a47e4a836e8eef2f | |
| parent | 626d2c5eed687e2c166d25f29cdfcaaba48f5f23 (diff) | |
| download | rust-6c34daff57101922dc97e1860bf5940ea88d3906.tar.gz rust-6c34daff57101922dc97e1860bf5940ea88d3906.zip | |
dec2flt: Rename fields to be consistent with documented notation
| -rw-r--r-- | library/core/src/num/dec2flt/common.rs | 13 | ||||
| -rw-r--r-- | library/core/src/num/dec2flt/lemire.rs | 4 | ||||
| -rw-r--r-- | library/core/src/num/dec2flt/mod.rs | 13 | ||||
| -rw-r--r-- | library/core/src/num/dec2flt/slow.rs | 2 | ||||
| -rw-r--r-- | library/coretests/tests/num/dec2flt/float.rs | 8 | ||||
| -rw-r--r-- | library/coretests/tests/num/dec2flt/lemire.rs | 4 |
6 files changed, 24 insertions, 20 deletions
diff --git a/library/core/src/num/dec2flt/common.rs b/library/core/src/num/dec2flt/common.rs index 1646d3a95d3..a140a311c45 100644 --- a/library/core/src/num/dec2flt/common.rs +++ b/library/core/src/num/dec2flt/common.rs @@ -63,19 +63,20 @@ pub(crate) fn is_8digits(v: u64) -> bool { (a | b) & 0x8080_8080_8080_8080 == 0 } -/// A custom 64-bit floating point type, representing `f * 2^e`. -/// e is biased, so it be directly shifted into the exponent bits. +/// A custom 64-bit floating point type, representing `m * 2^p`. +/// p is biased, so it be directly shifted into the exponent bits. #[derive(Debug, Copy, Clone, PartialEq, Eq, Default)] pub struct BiasedFp { /// The significant digits. - pub f: u64, + pub m: u64, /// The biased, binary exponent. - pub e: i32, + pub p_biased: i32, } impl BiasedFp { + /// Represent `0 ^ p` #[inline] - pub const fn zero_pow2(e: i32) -> Self { - Self { f: 0, e } + pub const fn zero_pow2(p_biased: i32) -> Self { + Self { m: 0, p_biased } } } diff --git a/library/core/src/num/dec2flt/lemire.rs b/library/core/src/num/dec2flt/lemire.rs index 01642e1b111..0cc39cb9b62 100644 --- a/library/core/src/num/dec2flt/lemire.rs +++ b/library/core/src/num/dec2flt/lemire.rs @@ -73,7 +73,7 @@ pub fn compute_float<F: RawFloat>(q: i64, mut w: u64) -> BiasedFp { mantissa += mantissa & 1; mantissa >>= 1; power2 = (mantissa >= (1_u64 << F::MANTISSA_EXPLICIT_BITS)) as i32; - return BiasedFp { f: mantissa, e: power2 }; + return BiasedFp { m: mantissa, p_biased: power2 }; } // Need to handle rounding ties. Normally, we need to round up, // but if we fall right in between and we have an even basis, we @@ -111,7 +111,7 @@ pub fn compute_float<F: RawFloat>(q: i64, mut w: u64) -> BiasedFp { // Exponent is above largest normal value, must be infinite. return fp_inf; } - BiasedFp { f: mantissa, e: power2 } + BiasedFp { m: mantissa, p_biased: power2 } } /// Calculate a base 2 exponent from a decimal exponent. diff --git a/library/core/src/num/dec2flt/mod.rs b/library/core/src/num/dec2flt/mod.rs index a82c858df49..9d1989c4b81 100644 --- a/library/core/src/num/dec2flt/mod.rs +++ b/library/core/src/num/dec2flt/mod.rs @@ -233,8 +233,8 @@ pub fn pfe_invalid() -> ParseFloatError { /// Converts a `BiasedFp` to the closest machine float type. fn biased_fp_to_float<T: RawFloat>(x: BiasedFp) -> T { - let mut word = x.f; - word |= (x.e as u64) << T::MANTISSA_EXPLICIT_BITS; + let mut word = x.m; + word |= (x.p_biased as u64) << T::MANTISSA_EXPLICIT_BITS; T::from_u64_bits(word) } @@ -272,12 +272,15 @@ pub fn dec2flt<F: RawFloat>(s: &str) -> Result<F, ParseFloatError> { // redundantly using the Eisel-Lemire algorithm if it was unable to // correctly round on the first pass. let mut fp = compute_float::<F>(num.exponent, num.mantissa); - if num.many_digits && fp.e >= 0 && fp != compute_float::<F>(num.exponent, num.mantissa + 1) { - fp.e = -1; + if num.many_digits + && fp.p_biased >= 0 + && fp != compute_float::<F>(num.exponent, num.mantissa + 1) + { + fp.p_biased = -1; } // Unable to correctly round the float using the Eisel-Lemire algorithm. // Fallback to a slower, but always correct algorithm. - if fp.e < 0 { + if fp.p_biased < 0 { fp = parse_long_mantissa::<F>(s); } diff --git a/library/core/src/num/dec2flt/slow.rs b/library/core/src/num/dec2flt/slow.rs index e274e1aa0aa..e0c4ae117da 100644 --- a/library/core/src/num/dec2flt/slow.rs +++ b/library/core/src/num/dec2flt/slow.rs @@ -105,5 +105,5 @@ pub(crate) fn parse_long_mantissa<F: RawFloat>(s: &[u8]) -> BiasedFp { } // Zero out all the bits above the explicit mantissa bits. mantissa &= (1_u64 << F::MANTISSA_EXPLICIT_BITS) - 1; - BiasedFp { f: mantissa, e: power2 } + BiasedFp { m: mantissa, p_biased: power2 } } diff --git a/library/coretests/tests/num/dec2flt/float.rs b/library/coretests/tests/num/dec2flt/float.rs index 7a9587a18d0..40f0776e021 100644 --- a/library/coretests/tests/num/dec2flt/float.rs +++ b/library/coretests/tests/num/dec2flt/float.rs @@ -12,8 +12,8 @@ fn test_f32_integer_decode() { // Ignore the "sign" (quiet / signalling flag) of NAN. // It can vary between runtime operations and LLVM folding. - let (nan_m, nan_e, _nan_s) = f32::NAN.integer_decode(); - assert_eq!((nan_m, nan_e), (12582912, 105)); + let (nan_m, nan_p, _nan_s) = f32::NAN.integer_decode(); + assert_eq!((nan_m, nan_p), (12582912, 105)); } #[test] @@ -28,6 +28,6 @@ fn test_f64_integer_decode() { // Ignore the "sign" (quiet / signalling flag) of NAN. // It can vary between runtime operations and LLVM folding. - let (nan_m, nan_e, _nan_s) = f64::NAN.integer_decode(); - assert_eq!((nan_m, nan_e), (6755399441055744, 972)); + let (nan_m, nan_p, _nan_s) = f64::NAN.integer_decode(); + assert_eq!((nan_m, nan_p), (6755399441055744, 972)); } diff --git a/library/coretests/tests/num/dec2flt/lemire.rs b/library/coretests/tests/num/dec2flt/lemire.rs index f71bbb7c7a3..9f228a25e46 100644 --- a/library/coretests/tests/num/dec2flt/lemire.rs +++ b/library/coretests/tests/num/dec2flt/lemire.rs @@ -2,12 +2,12 @@ use core::num::dec2flt::lemire::compute_float; fn compute_float32(q: i64, w: u64) -> (i32, u64) { let fp = compute_float::<f32>(q, w); - (fp.e, fp.f) + (fp.p_biased, fp.m) } fn compute_float64(q: i64, w: u64) -> (i32, u64) { let fp = compute_float::<f64>(q, w); - (fp.e, fp.f) + (fp.p_biased, fp.m) } #[test] |
