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1 //===-- Single-precision sinh function ------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "src/math/sinhf.h"
10 #include "src/__support/FPUtil/FPBits.h"
11 #include "src/__support/FPUtil/rounding_mode.h"
12 #include "src/__support/macros/optimization.h" // LIBC_UNLIKELY
13 #include "src/math/generic/explogxf.h"
14 
15 namespace LIBC_NAMESPACE {
16 
17 LLVM_LIBC_FUNCTION(float, sinhf, (float x)) {
18   using FPBits = typename fputil::FPBits<float>;
19   FPBits xbits(x);
20   uint32_t x_abs = xbits.abs().uintval();
21 
22   // When |x| >= 90, or x is inf or nan
23   if (LIBC_UNLIKELY(x_abs >= 0x42b4'0000U || x_abs <= 0x3da0'0000U)) {
24     // |x| <= 0.078125
25     if (x_abs <= 0x3da0'0000U) {
26       // |x| = 0.0005589424981735646724700927734375
27       if (LIBC_UNLIKELY(x_abs == 0x3a12'85ffU)) {
28         if (fputil::fenv_is_round_to_nearest())
29           return x;
30       }
31 
32       // |x| <= 2^-26
33       if (LIBC_UNLIKELY(x_abs <= 0x3280'0000U)) {
34         return static_cast<float>(
35             LIBC_UNLIKELY(x_abs == 0) ? x : (x + 0.25 * x * x * x));
36       }
37 
38       double xdbl = x;
39       double x2 = xdbl * xdbl;
40       // Sollya: fpminimax(sinh(x),[|3,5,7|],[|D...|],[-1/16-1/64;1/16+1/64],x);
41       // Sollya output: x * (0x1p0 + x^0x1p1 * (0x1.5555555556583p-3 + x^0x1p1
42       //                  * (0x1.111110d239f1fp-7
43       //                  + x^0x1p1 * 0x1.a02b5a284013cp-13)))
44       // Therefore, output of Sollya = x * pe;
45       double pe = fputil::polyeval(x2, 0.0, 0x1.5555555556583p-3,
46                                    0x1.111110d239f1fp-7, 0x1.a02b5a284013cp-13);
47       return static_cast<float>(fputil::multiply_add(xdbl, pe, xdbl));
48     }
49 
50     if (xbits.is_nan())
51       return x + 1.0f; // sNaN to qNaN + signal
52 
53     if (xbits.is_inf())
54       return x;
55 
56     int rounding = fputil::quick_get_round();
57     if (xbits.is_neg()) {
58       if (LIBC_UNLIKELY(rounding == FE_UPWARD || rounding == FE_TOWARDZERO))
59         return -FPBits::max_normal().get_val();
60     } else {
61       if (LIBC_UNLIKELY(rounding == FE_DOWNWARD || rounding == FE_TOWARDZERO))
62         return FPBits::max_normal().get_val();
63     }
64 
65     fputil::set_errno_if_required(ERANGE);
66     fputil::raise_except_if_required(FE_OVERFLOW);
67 
68     return x + FPBits::inf(xbits.sign()).get_val();
69   }
70 
71   // sinh(x) = (e^x - e^(-x)) / 2.
72   return static_cast<float>(exp_pm_eval</*is_sinh*/ true>(x));
73 }
74 
75 } // namespace LIBC_NAMESPACE
76