| Index: fusl/src/math/tanh.c
|
| diff --git a/fusl/src/math/tanh.c b/fusl/src/math/tanh.c
|
| index 20d6dbcf4175c7aad93fe70a53056f0d3e1c4f13..13fe2f6b6ee8a479acdf83e903a1859cf7051aeb 100644
|
| --- a/fusl/src/math/tanh.c
|
| +++ b/fusl/src/math/tanh.c
|
| @@ -4,42 +4,45 @@
|
| * = (exp(2*x) - 1)/(exp(2*x) - 1 + 2)
|
| * = (1 - exp(-2*x))/(exp(-2*x) - 1 + 2)
|
| */
|
| -double tanh(double x)
|
| -{
|
| - union {double f; uint64_t i;} u = {.f = x};
|
| - uint32_t w;
|
| - int sign;
|
| - double_t t;
|
| +double tanh(double x) {
|
| + union {
|
| + double f;
|
| + uint64_t i;
|
| + } u = {.f = x};
|
| + uint32_t w;
|
| + int sign;
|
| + double_t t;
|
|
|
| - /* x = |x| */
|
| - sign = u.i >> 63;
|
| - u.i &= (uint64_t)-1/2;
|
| - x = u.f;
|
| - w = u.i >> 32;
|
| + /* x = |x| */
|
| + sign = u.i >> 63;
|
| + u.i &= (uint64_t)-1 / 2;
|
| + x = u.f;
|
| + w = u.i >> 32;
|
|
|
| - if (w > 0x3fe193ea) {
|
| - /* |x| > log(3)/2 ~= 0.5493 or nan */
|
| - if (w > 0x40340000) {
|
| - /* |x| > 20 or nan */
|
| - /* note: this branch avoids raising overflow */
|
| - t = 1 - 0/x;
|
| - } else {
|
| - t = expm1(2*x);
|
| - t = 1 - 2/(t+2);
|
| - }
|
| - } else if (w > 0x3fd058ae) {
|
| - /* |x| > log(5/3)/2 ~= 0.2554 */
|
| - t = expm1(2*x);
|
| - t = t/(t+2);
|
| - } else if (w >= 0x00100000) {
|
| - /* |x| >= 0x1p-1022, up to 2ulp error in [0.1,0.2554] */
|
| - t = expm1(-2*x);
|
| - t = -t/(t+2);
|
| - } else {
|
| - /* |x| is subnormal */
|
| - /* note: the branch above would not raise underflow in [0x1p-1023,0x1p-1022) */
|
| - FORCE_EVAL((float)x);
|
| - t = x;
|
| - }
|
| - return sign ? -t : t;
|
| + if (w > 0x3fe193ea) {
|
| + /* |x| > log(3)/2 ~= 0.5493 or nan */
|
| + if (w > 0x40340000) {
|
| + /* |x| > 20 or nan */
|
| + /* note: this branch avoids raising overflow */
|
| + t = 1 - 0 / x;
|
| + } else {
|
| + t = expm1(2 * x);
|
| + t = 1 - 2 / (t + 2);
|
| + }
|
| + } else if (w > 0x3fd058ae) {
|
| + /* |x| > log(5/3)/2 ~= 0.2554 */
|
| + t = expm1(2 * x);
|
| + t = t / (t + 2);
|
| + } else if (w >= 0x00100000) {
|
| + /* |x| >= 0x1p-1022, up to 2ulp error in [0.1,0.2554] */
|
| + t = expm1(-2 * x);
|
| + t = -t / (t + 2);
|
| + } else {
|
| + /* |x| is subnormal */
|
| + /* note: the branch above would not raise underflow in [0x1p-1023,0x1p-1022)
|
| + */
|
| + FORCE_EVAL((float)x);
|
| + t = x;
|
| + }
|
| + return sign ? -t : t;
|
| }
|
|
|