reactos/sdk/lib/crt/math/scalbnf.c
2025-06-30 09:19:47 +00:00

41 lines
858 B
C

/*
* PROJECT: ReactOS CRT
* LICENSE: MIT (https://spdx.org/licenses/MIT)
* PURPOSE: Implementation of scalbnf.
* COPYRIGHT: Imported from musl libc
* https://git.musl-libc.org/cgit/musl/tree/src/math/scalbnf.c
* blob: a5ad208b69929f24336fae40e6af37101c99a72f
* See https://git.musl-libc.org/cgit/musl/tree/COPYRIGHT
*/
#include <math.h>
#include <stdint.h>
float scalbnf(float x, int n)
{
union {float f; uint32_t i;} u;
float_t y = x;
if (n > 127) {
y *= 0x1p127f;
n -= 127;
if (n > 127) {
y *= 0x1p127f;
n -= 127;
if (n > 127)
n = 127;
}
} else if (n < -126) {
y *= 0x1p-126f * 0x1p24f;
n += 126 - 24;
if (n < -126) {
y *= 0x1p-126f * 0x1p24f;
n += 126 - 24;
if (n < -126)
n = -126;
}
}
u.i = (uint32_t)(0x7f+n)<<23;
x = y * u.f;
return x;
}