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erikdesjardinserikdesjardins
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add license and other comments to existing files
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‎src/math/expf.rs

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/* origin: FreeBSD /usr/src/lib/msun/src/e_expf.c */
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/*
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* Conversion to float by Ian Lance Taylor, Cygnus Support, [email protected].
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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use super::scalbnf;
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const HALF: [f32; 2] = [0.5, -0.5];

‎src/math/log10.rs

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/* origin: FreeBSD /usr/src/lib/msun/src/e_log10.c */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunSoft, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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/*
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* Return the base 10 logarithm of x. See log.c for most comments.
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*
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* Reduce x to 2^k (1+f) and calculate r = log(1+f) - f + f*f/2
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* as in log.c, then combine and scale in extra precision:
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* log10(x) = (f - f*f/2 + r)/log(10) + k*log10(2)
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*/
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use core::f64;
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const IVLN10HI: f64 = 4.34294481878168880939e-01; /* 0x3fdbcb7b, 0x15200000 */

‎src/math/log10f.rs

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/* origin: FreeBSD /usr/src/lib/msun/src/e_log10f.c */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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/*
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* See comments in log10.c.
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*/
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use core::f32;
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const IVLN10HI: f32 = 4.3432617188e-01; /* 0x3ede6000 */

‎src/math/log2.rs

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/* origin: FreeBSD /usr/src/lib/msun/src/e_log2.c */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunSoft, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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/*
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* Return the base 2 logarithm of x. See log.c for most comments.
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*
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* Reduce x to 2^k (1+f) and calculate r = log(1+f) - f + f*f/2
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* as in log.c, then combine and scale in extra precision:
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* log2(x) = (f - f*f/2 + r)/log(2) + k
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*/
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use core::f64;
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const IVLN2HI: f64 = 1.44269504072144627571e+00; /* 0x3ff71547, 0x65200000 */

‎src/math/log2f.rs

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/* origin: FreeBSD /usr/src/lib/msun/src/e_log2f.c */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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/*
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* See comments in log2.c.
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*/
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use core::f32;
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const IVLN2HI: f32 = 1.4428710938e+00; /* 0x3fb8b000 */

‎src/math/logf.rs

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/* origin: FreeBSD /usr/src/lib/msun/src/e_logf.c */
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/*
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* Conversion to float by Ian Lance Taylor, Cygnus Support, [email protected].
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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const LN2_HI: f32 = 6.9313812256e-01; /* 0x3f317180 */
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const LN2_LO: f32 = 9.0580006145e-06; /* 0x3717f7d1 */
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/* |(log(1+s)-log(1-s))/s - Lg(s)| < 2**-34.24 (~[-4.95e-11, 4.97e-11]). */

‎src/math/powf.rs

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/* origin: FreeBSD /usr/src/lib/msun/src/e_powf.c */
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/*
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* Conversion to float by Ian Lance Taylor, Cygnus Support, [email protected].
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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use super::{fabsf, scalbnf, sqrtf};
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const BP: [f32; 2] = [1.0, 1.5];

‎src/math/sqrt.rs

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/* origin: FreeBSD /usr/src/lib/msun/src/e_sqrt.c */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunSoft, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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/* sqrt(x)
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* Return correctly rounded sqrt.
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* ------------------------------------------
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* | Use the hardware sqrt if you have one |
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* ------------------------------------------
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* Method:
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* Bit by bit method using integer arithmetic. (Slow, but portable)
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* 1. Normalization
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* Scale x to y in [1,4) with even powers of 2:
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* find an integer k such that 1 <= (y=x*2^(2k)) < 4, then
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* sqrt(x) = 2^k * sqrt(y)
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* 2. Bit by bit computation
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* Let q = sqrt(y) truncated to i bit after binary point (q = 1),
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* i 0
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* i+1 2
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* s = 2*q , and y = 2 * ( y - q ). (1)
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* i i i i
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*
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* To compute q from q , one checks whether
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* i+1 i
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*
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* -(i+1) 2
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* (q + 2 ) <= y. (2)
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* i
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* -(i+1)
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* If (2) is false, then q = q ; otherwise q = q + 2 .
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* i+1 i i+1 i
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*
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* With some algebric manipulation, it is not difficult to see
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* that (2) is equivalent to
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* -(i+1)
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* s + 2 <= y (3)
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* i i
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*
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* The advantage of (3) is that s and y can be computed by
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* i i
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* the following recurrence formula:
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* if (3) is false
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*
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* s = s , y = y ; (4)
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* i+1 i i+1 i
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*
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* otherwise,
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* -i -(i+1)
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* s = s + 2 , y = y - s - 2 (5)
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* i+1 i i+1 i i
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*
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* One may easily use induction to prove (4) and (5).
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* Note. Since the left hand side of (3) contain only i+2 bits,
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* it does not necessary to do a full (53-bit) comparison
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* in (3).
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* 3. Final rounding
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* After generating the 53 bits result, we compute one more bit.
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* Together with the remainder, we can decide whether the
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* result is exact, bigger than 1/2ulp, or less than 1/2ulp
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* (it will never equal to 1/2ulp).
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* The rounding mode can be detected by checking whether
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* huge + tiny is equal to huge, and whether huge - tiny is
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* equal to huge for some floating point number "huge" and "tiny".
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*
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* Special cases:
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* sqrt(+-0) = +-0 ... exact
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* sqrt(inf) = inf
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* sqrt(-ve) = NaN ... with invalid signal
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* sqrt(NaN) = NaN ... with invalid signal for signaling NaN
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*/
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use core::f64;
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const TINY: f64 = 1.0e-300;

‎src/math/sqrtf.rs

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/* origin: FreeBSD /usr/src/lib/msun/src/e_sqrtf.c */
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/*
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* Conversion to float by Ian Lance Taylor, Cygnus Support, [email protected].
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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const TINY: f32 = 1.0e-30;
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#[inline]

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