From 1b6a04ca5504955c571d1c97504fb45ea0befee4 Mon Sep 17 00:00:00 2001 From: Valentin Popov Date: Mon, 8 Jan 2024 01:21:28 +0400 Subject: Initial vendor packages Signed-off-by: Valentin Popov --- vendor/serde_json/src/lexical/cached.rs | 82 +++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 vendor/serde_json/src/lexical/cached.rs (limited to 'vendor/serde_json/src/lexical/cached.rs') diff --git a/vendor/serde_json/src/lexical/cached.rs b/vendor/serde_json/src/lexical/cached.rs new file mode 100644 index 0000000..ef5a9fe --- /dev/null +++ b/vendor/serde_json/src/lexical/cached.rs @@ -0,0 +1,82 @@ +// Adapted from https://github.com/Alexhuszagh/rust-lexical. + +//! Cached powers trait for extended-precision floats. + +use super::cached_float80; +use super::float::ExtendedFloat; + +// POWERS + +/// Precalculated powers that uses two-separate arrays for memory-efficiency. +#[doc(hidden)] +pub(crate) struct ExtendedFloatArray { + // Pre-calculated mantissa for the powers. + pub mant: &'static [u64], + // Pre-calculated binary exponents for the powers. + pub exp: &'static [i32], +} + +/// Allow indexing of values without bounds checking +impl ExtendedFloatArray { + #[inline] + pub fn get_extended_float(&self, index: usize) -> ExtendedFloat { + let mant = self.mant[index]; + let exp = self.exp[index]; + ExtendedFloat { mant, exp } + } + + #[inline] + pub fn len(&self) -> usize { + self.mant.len() + } +} + +// MODERATE PATH POWERS + +/// Precalculated powers of base N for the moderate path. +#[doc(hidden)] +pub(crate) struct ModeratePathPowers { + // Pre-calculated small powers. + pub small: ExtendedFloatArray, + // Pre-calculated large powers. + pub large: ExtendedFloatArray, + /// Pre-calculated small powers as 64-bit integers + pub small_int: &'static [u64], + // Step between large powers and number of small powers. + pub step: i32, + // Exponent bias for the large powers. + pub bias: i32, +} + +/// Allow indexing of values without bounds checking +impl ModeratePathPowers { + #[inline] + pub fn get_small(&self, index: usize) -> ExtendedFloat { + self.small.get_extended_float(index) + } + + #[inline] + pub fn get_large(&self, index: usize) -> ExtendedFloat { + self.large.get_extended_float(index) + } + + #[inline] + pub fn get_small_int(&self, index: usize) -> u64 { + self.small_int[index] + } +} + +// CACHED EXTENDED POWERS + +/// Cached powers as a trait for a floating-point type. +pub(crate) trait ModeratePathCache { + /// Get cached powers. + fn get_powers() -> &'static ModeratePathPowers; +} + +impl ModeratePathCache for ExtendedFloat { + #[inline] + fn get_powers() -> &'static ModeratePathPowers { + cached_float80::get_powers() + } +} -- cgit v1.2.3