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-rw-r--r--vendor/compiler_builtins/libm/src/math/tanf.rs78
1 files changed, 78 insertions, 0 deletions
diff --git a/vendor/compiler_builtins/libm/src/math/tanf.rs b/vendor/compiler_builtins/libm/src/math/tanf.rs
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+/* 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)
+}