From b32a462b2ee7a04b73b8c5c474490725cb726801 Mon Sep 17 00:00:00 2001 From: joe-conigliaro Date: Thu, 17 Oct 2019 17:04:57 +1100 Subject: [PATCH] math: new consts + helpers funcs for string to int / float --- vlib/math/bits.v | 58 +++++++++++++++++++++++++++++++++++++++++++++++ vlib/math/const.v | 50 ++++++++++++++++++++++++++++++++++++++++ vlib/math/math.v | 33 --------------------------- 3 files changed, 108 insertions(+), 33 deletions(-) create mode 100644 vlib/math/bits.v create mode 100644 vlib/math/const.v diff --git a/vlib/math/bits.v b/vlib/math/bits.v new file mode 100644 index 0000000000..b1a0241e4a --- /dev/null +++ b/vlib/math/bits.v @@ -0,0 +1,58 @@ +// Copyright (c) 2019 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 = 0x7FF8000000000001 + uvinf = 0x7FF0000000000000 + uvneginf = 0xFFF0000000000000 + uvone = 0x3FF0000000000000 + mask = 0x7FF + shift = 64 - 11 - 1 + bias = 1023 + sign_mask = u64(u64(1) << 63) + frac_mask = u64(u64(u64(1)<= 0, negative infinity if sign < 0. +pub fn inf(sign int) f64 { + v := if sign >= 0 { uvinf } else { uvneginf } + return f64_from_bits(v) +} + +// nan returns an IEEE 754 ``not-a-number'' value. +pub fn nan() f64 { return f64_from_bits(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) +} + +// NOTE: (joe-c) exponent notation is borked +// 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 * (1 << 52), -52 +// } +// return x, 0 +// } diff --git a/vlib/math/const.v b/vlib/math/const.v new file mode 100644 index 0000000000..2d29a19f17 --- /dev/null +++ b/vlib/math/const.v @@ -0,0 +1,50 @@ +// Copyright (c) 2019 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 ( + e = 2.71828182845904523536028747135266249775724709369995957496696763 + pi = 3.14159265358979323846264338327950288419716939937510582097494459 + phi = 1.61803398874989484820458683436563811772030917980576286213544862 + tau = 6.28318530717958647692528676655900576839433879875021164194988918 + + sqrt2 = 1.41421356237309504880168872420969807856967187537694807317667974 + sqrt_e = 1.64872127070012814684865078781416357165377610071014801157507931 + sqrt_pi = 1.77245385090551602729816748334114518279754945612238712821380779 + sqrt_tau = 2.50662827463100050241576528481104525300698674060993831662992357 + sqrt_phi = 1.27201964951406896425242246173749149171560804184009624861664038 + + ln2 = 0.693147180559945309417232121458176568075500134360255254120680009 + log2_e = 1.0 / ln2 + ln10 = 2.30258509299404568401799145468436420760110148862877297603332790 + log10_e = 1.0 / ln10 +) + +// Floating-point limit values +// max is the largest finite value representable by the type. +// smallest_non_zero is the smallest positive, non-zero value representable by the type. +const ( + max_f32 = 3.40282346638528859811704183484516925440e+38 // 2**127 * (2**24 - 1) / 2**23 + smallest_non_zero_f32 = 1.401298464324817070923729583289916131280e-45 // 1 / 2**(127 - 1 + 23) + + max_f64 = 1.797693134862315708145274237317043567981e+308 // 2**1023 * (2**53 - 1) / 2**52 + smallest_non_zero_f64 = 4.940656458412465441765687928682213723651e-324 // 1 / 2**(1023 - 1 + 52) +) + +// Integer limit values +const ( + max_i8 = 127 + min_i8 = -128 + max_i16 = 32767 + min_i16 = -32768 + max_i32 = 2147483647 + min_i32 = -2147483648 + min_i64 = -9223372036854775808 + max_i64 = 9223372036854775807 + max_u8 = 255 + max_u16 = 65535 + max_u32 = 4294967295 + max_u64 = 18446744073709551615 +) diff --git a/vlib/math/math.v b/vlib/math/math.v index 3088ef6af4..e6665f3f01 100644 --- a/vlib/math/math.v +++ b/vlib/math/math.v @@ -10,39 +10,6 @@ module math // When adding a new function, please make sure it's in the right place. // All functions are sorted alphabetically. -const ( - e = 2.71828182845904523536028747135266249775724709369995957496696763 - pi = 3.14159265358979323846264338327950288419716939937510582097494459 - phi = 1.61803398874989484820458683436563811772030917980576286213544862 - tau = 6.28318530717958647692528676655900576839433879875021164194988918 - - sqrt2 = 1.41421356237309504880168872420969807856967187537694807317667974 - sqrt_e = 1.64872127070012814684865078781416357165377610071014801157507931 - sqrt_pi = 1.77245385090551602729816748334114518279754945612238712821380779 - sqrt_tau = 2.50662827463100050241576528481104525300698674060993831662992357 - sqrt_phi = 1.27201964951406896425242246173749149171560804184009624861664038 - - ln2 = 0.693147180559945309417232121458176568075500134360255254120680009 - log2_e = 1.0 / ln2 - ln10 = 2.30258509299404568401799145468436420760110148862877297603332790 - log10_e = 1.0 / ln10 -) - -const ( - max_i8 = 127 - min_i8 = -128 - max_i16 = 32767 - min_i16 = -32768 - max_i32 = 2147483647 - min_i32 = -2147483648 -// MaxI64 = ((1<<63) - 1) -// MinI64 = (-(1 << 63) ) - max_u8 = 255 - max_u16 = 65535 - max_u32 = 4294967295 - max_u64 = 18446744073709551615 -) - // Returns the absolute value. pub fn abs(a f64) f64 { if a < 0 {