Files
agnostic_orderbook
ahash
aho_corasick
arrayref
arrayvec
atty
base64
bincode
blake3
block_buffer
block_padding
borsh
borsh_derive
borsh_derive_internal
borsh_schema_derive_internal
bs58
bv
bytemuck
byteorder
cfg_if
constant_time_eq
cpufeatures
crunchy
crypto_mac
curve25519_dalek
derivative
dex_v3
digest
either
enumflags2
enumflags2_derive
env_logger
generic_array
getrandom
hashbrown
hex
hmac
hmac_drbg
humantime
itertools
keccak
lazy_static
libc
libm
libsecp256k1
libsecp256k1_core
log
memchr
memmap2
num_derive
num_enum
num_enum_derive
num_traits
opaque_debug
ppv_lite86
proc_macro2
quote
rand
rand_chacha
rand_core
rand_pcg
regex
regex_syntax
rustversion
serde
serde_bytes
serde_derive
sha2
sha3
solana_frozen_abi
solana_frozen_abi_macro
solana_logger
solana_program
solana_sdk_macro
spin
spl_token
subtle
syn
synstructure
termcolor
thiserror
thiserror_impl
typenum
unicode_xid
zeroize
zeroize_derive
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
use super::log1p;

/* atanh(x) = log((1+x)/(1-x))/2 = log1p(2x/(1-x))/2 ~= x + x^3/3 + o(x^5) */
/// Inverse hyperbolic tangent (f64)
///
/// Calculates the inverse hyperbolic tangent of `x`.
/// Is defined as `log((1+x)/(1-x))/2 = log1p(2x/(1-x))/2`.
pub fn atanh(x: f64) -> f64 {
    let u = x.to_bits();
    let e = ((u >> 52) as usize) & 0x7ff;
    let sign = (u >> 63) != 0;

    /* |x| */
    let mut y = f64::from_bits(u & 0x7fff_ffff_ffff_ffff);

    if e < 0x3ff - 1 {
        if e < 0x3ff - 32 {
            /* handle underflow */
            if e == 0 {
                force_eval!(y as f32);
            }
        } else {
            /* |x| < 0.5, up to 1.7ulp error */
            y = 0.5 * log1p(2.0 * y + 2.0 * y * y / (1.0 - y));
        }
    } else {
        /* avoid overflow */
        y = 0.5 * log1p(2.0 * (y / (1.0 - y)));
    }

    if sign {
        -y
    } else {
        y
    }
}