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-rw-r--r--vendor/compiler_builtins/libm/src/math/rem_pio2f.rs67
1 files changed, 67 insertions, 0 deletions
diff --git a/vendor/compiler_builtins/libm/src/math/rem_pio2f.rs b/vendor/compiler_builtins/libm/src/math/rem_pio2f.rs
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+++ b/vendor/compiler_builtins/libm/src/math/rem_pio2f.rs
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+/* origin: FreeBSD /usr/src/lib/msun/src/e_rem_pio2f.c */
+/*
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ * Debugged and 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::rem_pio2_large;
+
+use core::f64;
+
+const TOINT: f64 = 1.5 / f64::EPSILON;
+
+/// 53 bits of 2/pi
+const INV_PIO2: f64 = 6.36619772367581382433e-01; /* 0x3FE45F30, 0x6DC9C883 */
+/// first 25 bits of pi/2
+const PIO2_1: f64 = 1.57079631090164184570e+00; /* 0x3FF921FB, 0x50000000 */
+/// pi/2 - pio2_1
+const PIO2_1T: f64 = 1.58932547735281966916e-08; /* 0x3E5110b4, 0x611A6263 */
+
+/// Return the remainder of x rem pi/2 in *y
+///
+/// use double precision for everything except passing x
+/// use __rem_pio2_large() for large x
+#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
+pub(crate) fn rem_pio2f(x: f32) -> (i32, f64) {
+ let x64 = x as f64;
+
+ let mut tx: [f64; 1] = [0.];
+ let mut ty: [f64; 1] = [0.];
+
+ let ix = x.to_bits() & 0x7fffffff;
+ /* 25+53 bit pi is good enough for medium size */
+ if ix < 0x4dc90fdb {
+ /* |x| ~< 2^28*(pi/2), medium size */
+ /* Use a specialized rint() to get fn. Assume round-to-nearest. */
+ let tmp = x64 * INV_PIO2 + TOINT;
+ // force rounding of tmp to it's storage format on x87 to avoid
+ // excess precision issues.
+ #[cfg(all(target_arch = "x86", not(target_feature = "sse2")))]
+ let tmp = force_eval!(tmp);
+ let f_n = tmp - TOINT;
+ return (f_n as i32, x64 - f_n * PIO2_1 - f_n * PIO2_1T);
+ }
+ if ix >= 0x7f800000 {
+ /* x is inf or NaN */
+ return (0, x64 - x64);
+ }
+ /* scale x into [2^23, 2^24-1] */
+ let sign = (x.to_bits() >> 31) != 0;
+ let e0 = ((ix >> 23) - (0x7f + 23)) as i32; /* e0 = ilogb(|x|)-23, positive */
+ tx[0] = f32::from_bits(ix - (e0 << 23) as u32) as f64;
+ let n = rem_pio2_large(&tx, &mut ty, e0, 0);
+ if sign {
+ return (-n, -ty[0]);
+ }
+ (n, ty[0])
+}