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Diffstat (limited to '')
-rw-r--r-- | vendor/ryu/src/d2s_intrinsics.rs | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/vendor/ryu/src/d2s_intrinsics.rs b/vendor/ryu/src/d2s_intrinsics.rs new file mode 100644 index 000000000..f244a4d03 --- /dev/null +++ b/vendor/ryu/src/d2s_intrinsics.rs @@ -0,0 +1,89 @@ +// Translated from C to Rust. The original C code can be found at +// https://github.com/ulfjack/ryu and carries the following license: +// +// Copyright 2018 Ulf Adams +// +// The contents of this file may be used under the terms of the Apache License, +// Version 2.0. +// +// (See accompanying file LICENSE-Apache or copy at +// http://www.apache.org/licenses/LICENSE-2.0) +// +// Alternatively, the contents of this file may be used under the terms of +// the Boost Software License, Version 1.0. +// (See accompanying file LICENSE-Boost or copy at +// https://www.boost.org/LICENSE_1_0.txt) +// +// Unless required by applicable law or agreed to in writing, this software +// is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. + +use core::ptr; + +#[cfg_attr(feature = "no-panic", inline)] +pub fn div5(x: u64) -> u64 { + x / 5 +} + +#[cfg_attr(feature = "no-panic", inline)] +pub fn div10(x: u64) -> u64 { + x / 10 +} + +#[cfg_attr(feature = "no-panic", inline)] +pub fn div100(x: u64) -> u64 { + x / 100 +} + +#[cfg_attr(feature = "no-panic", inline)] +fn pow5_factor(mut value: u64) -> u32 { + let mut count = 0u32; + loop { + debug_assert!(value != 0); + let q = div5(value); + let r = (value as u32).wrapping_sub(5u32.wrapping_mul(q as u32)); + if r != 0 { + break; + } + value = q; + count += 1; + } + count +} + +// Returns true if value is divisible by 5^p. +#[cfg_attr(feature = "no-panic", inline)] +pub fn multiple_of_power_of_5(value: u64, p: u32) -> bool { + // I tried a case distinction on p, but there was no performance difference. + pow5_factor(value) >= p +} + +// Returns true if value is divisible by 2^p. +#[cfg_attr(feature = "no-panic", inline)] +pub fn multiple_of_power_of_2(value: u64, p: u32) -> bool { + debug_assert!(value != 0); + debug_assert!(p < 64); + // __builtin_ctzll doesn't appear to be faster here. + (value & ((1u64 << p) - 1)) == 0 +} + +#[cfg_attr(feature = "no-panic", inline)] +pub fn mul_shift_64(m: u64, mul: &(u64, u64), j: u32) -> u64 { + let b0 = m as u128 * mul.0 as u128; + let b2 = m as u128 * mul.1 as u128; + (((b0 >> 64) + b2) >> (j - 64)) as u64 +} + +#[cfg_attr(feature = "no-panic", inline)] +pub unsafe fn mul_shift_all_64( + m: u64, + mul: &(u64, u64), + j: u32, + vp: *mut u64, + vm: *mut u64, + mm_shift: u32, +) -> u64 { + ptr::write(vp, mul_shift_64(4 * m + 2, mul, j)); + ptr::write(vm, mul_shift_64(4 * m - 1 - mm_shift as u64, mul, j)); + mul_shift_64(4 * m, mul, j) +} |