ref: 0eabd603f8768063fb423d7b065fe1124837e2f2
dir: /libnpe/ldexpf.c/
#include <math.h>
/* taken from musl */
float ldexpf(float x, int n)
{
union {float f; u32int i;} u;
float y = x;
union {
float f;
u32int x;
}oneP[] = {
{.x = 0x7f000000},
{.x = 0x800000},
{.x = 0x4b800000},
};
if (n > 127) {
y *= oneP[0].f;
n -= 127;
if (n > 127) {
y *= oneP[0].f;
n -= 127;
if (n > 127)
n = 127;
}
} else if (n < -126) {
y *= oneP[1].f * oneP[2].f;
n += 126 - 24;
if (n < -126) {
y *= oneP[1].f * oneP[2].f;
n += 126 - 24;
if (n < -126)
n = -126;
}
}
u.i = (u32int)(0x7f+n)<<23;
x = y * u.f;
return x;
}