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Reactos
1/*
2 * PROJECT: ReactOS CRT
3 * LICENSE: MIT (https://spdx.org/licenses/MIT)
4 * PURPOSE: Implementation of scalbnf.
5 * COPYRIGHT: Imported from musl libc
6 * https://git.musl-libc.org/cgit/musl/tree/src/math/scalbnf.c
7 * blob: a5ad208b69929f24336fae40e6af37101c99a72f
8 * See https://git.musl-libc.org/cgit/musl/tree/COPYRIGHT
9 */
10
11#include <math.h>
12#include <stdint.h>
13
14float scalbnf(float x, int n)
15{
16 union {float f; uint32_t i;} u;
17 float_t y = x;
18
19 if (n > 127) {
20 y *= 0x1p127f;
21 n -= 127;
22 if (n > 127) {
23 y *= 0x1p127f;
24 n -= 127;
25 if (n > 127)
26 n = 127;
27 }
28 } else if (n < -126) {
29 y *= 0x1p-126f * 0x1p24f;
30 n += 126 - 24;
31 if (n < -126) {
32 y *= 0x1p-126f * 0x1p24f;
33 n += 126 - 24;
34 if (n < -126)
35 n = -126;
36 }
37 }
38 u.i = (uint32_t)(0x7f+n)<<23;
39 x = y * u.f;
40 return x;
41}