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author | Indrajith K L | 2022-12-03 17:00:20 +0530 |
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committer | Indrajith K L | 2022-12-03 17:00:20 +0530 |
commit | f5c4671bfbad96bf346bd7e9a21fc4317b4959df (patch) | |
tree | 2764fc62da58f2ba8da7ed341643fc359873142f /v_windows/v/vlib/math/bits.v | |
download | cli-tools-windows-master.tar.gz cli-tools-windows-master.tar.bz2 cli-tools-windows-master.zip |
Diffstat (limited to 'v_windows/v/vlib/math/bits.v')
-rw-r--r-- | v_windows/v/vlib/math/bits.v | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/v_windows/v/vlib/math/bits.v b/v_windows/v/vlib/math/bits.v new file mode 100644 index 0000000..deaf962 --- /dev/null +++ b/v_windows/v/vlib/math/bits.v @@ -0,0 +1,63 @@ +// Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved. +// Use of this source code is governed by an MIT license +// that can be found in the LICENSE file. +module math + +const ( + uvnan = u64(0x7FF8000000000001) + uvinf = u64(0x7FF0000000000000) + uvneginf = u64(0xFFF0000000000000) + uvone = u64(0x3FF0000000000000) + mask = 0x7FF + shift = 64 - 11 - 1 + bias = 1023 + normalize_smallest_mask = (u64(1) << 52) + sign_mask = (u64(1) << 63) + frac_mask = ((u64(1) << u64(shift)) - u64(1)) +) + +// inf returns positive infinity if sign >= 0, negative infinity if sign < 0. +pub fn inf(sign int) f64 { + v := if sign >= 0 { math.uvinf } else { math.uvneginf } + return f64_from_bits(v) +} + +// nan returns an IEEE 754 ``not-a-number'' value. +pub fn nan() f64 { + return f64_from_bits(math.uvnan) +} + +// is_nan reports whether f is an IEEE 754 ``not-a-number'' value. +pub fn is_nan(f f64) bool { + // IEEE 754 says that only NaNs satisfy f != f. + // To avoid the floating-point hardware, could use: + // x := f64_bits(f); + // return u32(x>>shift)&mask == mask && x != uvinf && x != uvneginf + return f != f +} + +// is_inf reports whether f is an infinity, according to sign. +// If sign > 0, is_inf reports whether f is positive infinity. +// If sign < 0, is_inf reports whether f is negative infinity. +// If sign == 0, is_inf reports whether f is either infinity. +pub fn is_inf(f f64, sign int) bool { + // Test for infinity by comparing against maximum float. + // To avoid the floating-point hardware, could use: + // x := f64_bits(f); + // return sign >= 0 && x == uvinf || sign <= 0 && x == uvneginf; + return (sign >= 0 && f > max_f64) || (sign <= 0 && f < -max_f64) +} + +pub fn is_finite(f f64) bool { + return !is_nan(f) && !is_inf(f, 0) +} + +// normalize returns a normal number y and exponent exp +// satisfying x == y × 2**exp. It assumes x is finite and non-zero. +pub fn normalize(x f64) (f64, int) { + smallest_normal := 2.2250738585072014e-308 // 2**-1022 + if abs(x) < smallest_normal { + return x * math.normalize_smallest_mask, -52 + } + return x, 0 +} |