fn acosh32(x: f32) f32 x: f3226
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42fn acosh32(x: f32) f32 {
const u = @as(u32, @bitCast(x));
const i = u & 0x7FFFFFFF;
// |x| < 2, invalid if x < 1 or nan
if (i < 0x3F800000 + (1 << 23)) {
return math.log1p(x - 1 + @sqrt((x - 1) * (x - 1) + 2 * (x - 1)));
}
// |x| < 0x1p12
else if (i < 0x3F800000 + (12 << 23)) {
return @log(2 * x - 1 / (x + @sqrt(x * x - 1)));
}
// |x| >= 0x1p12
else {
return @log(x) + 0.693147180559945309417232121458176568;
}
}
acosh(x) = log(x + sqrt(x * x - 1))