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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /third_party/rust/libm/src/math/tanf.rs | |
parent | Initial commit. (diff) | |
download | firefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz firefox-26a029d407be480d791972afb5975cf62c9360a6.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/libm/src/math/tanf.rs')
-rw-r--r-- | third_party/rust/libm/src/math/tanf.rs | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/third_party/rust/libm/src/math/tanf.rs b/third_party/rust/libm/src/math/tanf.rs new file mode 100644 index 0000000000..10de59c391 --- /dev/null +++ b/third_party/rust/libm/src/math/tanf.rs @@ -0,0 +1,78 @@ +/* origin: FreeBSD /usr/src/lib/msun/src/s_tanf.c */ +/* + * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. + * Optimized by Bruce D. Evans. + */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +use super::{k_tanf, rem_pio2f}; + +use core::f64::consts::FRAC_PI_2; + +/* Small multiples of pi/2 rounded to double precision. */ +const T1_PIO2: f64 = 1. * FRAC_PI_2; /* 0x3FF921FB, 0x54442D18 */ +const T2_PIO2: f64 = 2. * FRAC_PI_2; /* 0x400921FB, 0x54442D18 */ +const T3_PIO2: f64 = 3. * FRAC_PI_2; /* 0x4012D97C, 0x7F3321D2 */ +const T4_PIO2: f64 = 4. * FRAC_PI_2; /* 0x401921FB, 0x54442D18 */ + +#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] +pub fn tanf(x: f32) -> f32 { + let x64 = x as f64; + + let x1p120 = f32::from_bits(0x7b800000); // 0x1p120f === 2 ^ 120 + + let mut ix = x.to_bits(); + let sign = (ix >> 31) != 0; + ix &= 0x7fffffff; + + if ix <= 0x3f490fda { + /* |x| ~<= pi/4 */ + if ix < 0x39800000 { + /* |x| < 2**-12 */ + /* raise inexact if x!=0 and underflow if subnormal */ + force_eval!(if ix < 0x00800000 { + x / x1p120 + } else { + x + x1p120 + }); + return x; + } + return k_tanf(x64, false); + } + if ix <= 0x407b53d1 { + /* |x| ~<= 5*pi/4 */ + if ix <= 0x4016cbe3 { + /* |x| ~<= 3pi/4 */ + return k_tanf(if sign { x64 + T1_PIO2 } else { x64 - T1_PIO2 }, true); + } else { + return k_tanf(if sign { x64 + T2_PIO2 } else { x64 - T2_PIO2 }, false); + } + } + if ix <= 0x40e231d5 { + /* |x| ~<= 9*pi/4 */ + if ix <= 0x40afeddf { + /* |x| ~<= 7*pi/4 */ + return k_tanf(if sign { x64 + T3_PIO2 } else { x64 - T3_PIO2 }, true); + } else { + return k_tanf(if sign { x64 + T4_PIO2 } else { x64 - T4_PIO2 }, false); + } + } + + /* tan(Inf or NaN) is NaN */ + if ix >= 0x7f800000 { + return x - x; + } + + /* argument reduction */ + let (n, y) = rem_pio2f(x); + k_tanf(y, n & 1 != 0) +} |