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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /vendor/libm/src/math/cosf.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/libm/src/math/cosf.rs')
-rw-r--r-- | vendor/libm/src/math/cosf.rs | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/vendor/libm/src/math/cosf.rs b/vendor/libm/src/math/cosf.rs new file mode 100644 index 000000000..48d76c8ee --- /dev/null +++ b/vendor/libm/src/math/cosf.rs @@ -0,0 +1,84 @@ +/* origin: FreeBSD /usr/src/lib/msun/src/s_cosf.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_cosf, k_sinf, rem_pio2f}; + +use core::f64::consts::FRAC_PI_2; + +/* Small multiples of pi/2 rounded to double precision. */ +const C1_PIO2: f64 = 1. * FRAC_PI_2; /* 0x3FF921FB, 0x54442D18 */ +const C2_PIO2: f64 = 2. * FRAC_PI_2; /* 0x400921FB, 0x54442D18 */ +const C3_PIO2: f64 = 3. * FRAC_PI_2; /* 0x4012D97C, 0x7F3321D2 */ +const C4_PIO2: f64 = 4. * FRAC_PI_2; /* 0x401921FB, 0x54442D18 */ + +#[inline] +#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] +pub fn cosf(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 */ + force_eval!(x + x1p120); + return 1.; + } + return k_cosf(x64); + } + if ix <= 0x407b53d1 { + /* |x| ~<= 5*pi/4 */ + if ix > 0x4016cbe3 { + /* |x| ~> 3*pi/4 */ + return -k_cosf(if sign { x64 + C2_PIO2 } else { x64 - C2_PIO2 }); + } else if sign { + return k_sinf(x64 + C1_PIO2); + } else { + return k_sinf(C1_PIO2 - x64); + } + } + if ix <= 0x40e231d5 { + /* |x| ~<= 9*pi/4 */ + if ix > 0x40afeddf { + /* |x| ~> 7*pi/4 */ + return k_cosf(if sign { x64 + C4_PIO2 } else { x64 - C4_PIO2 }); + } else if sign { + return k_sinf(-x64 - C3_PIO2); + } else { + return k_sinf(x64 - C3_PIO2); + } + } + + /* cos(Inf or NaN) is NaN */ + if ix >= 0x7f800000 { + return x - x; + } + + /* general argument reduction needed */ + let (n, y) = rem_pio2f(x); + match n & 3 { + 0 => k_cosf(y), + 1 => k_sinf(-y), + 2 => -k_cosf(y), + _ => k_sinf(y), + } +} |