12 /* sqrt(x)
13  * Return correctly rounded sqrt.
15  *           |  Use the hardware sqrt if you have one |
22  *              sqrt(x) = 2^k * sqrt(y)
24  *      Let q  = sqrt(y) truncated to i bit after binary point (q = 1),
73  *      sqrt(+-0) = +-0         ... exact
74  *      sqrt(inf) = inf
75  *      sqrt(-ve) = NaN         ... with invalid signal
76  *      sqrt(NaN) = NaN         ... with invalid signal for signaling NaN
83 pub fn sqrt(x: f64) -> f64 {  in sqrt()  function
85     // `f64.sqrt` native instruction, so we can leverage this for both code size  in sqrt()
99         // optimized sqrt calls into hardware instructions if sse2 is available,  in sqrt()
136             return x * x + x; /* sqrt(NaN)=NaN, sqrt(+inf)=+inf, sqrt(-inf)=sNaN */  in sqrt()
141                 return x; /* sqrt(+-0) = +-0 */  in sqrt()
144                 return (x - x) / (x - x); /* sqrt(-ve) = sNaN */  in sqrt()
174         /* generate sqrt(x) bit by bit */  in sqrt()
177         q = 0; /* [q,q1] = sqrt(x) */  in sqrt()
252         assert_eq!(sqrt(100.0), 10.0);  in sanity_check()
253         assert_eq!(sqrt(4.0), 2.0);  in sanity_check()
256     /// The spec: https://en.cppreference.com/w/cpp/numeric/math/sqrt
260         assert!(sqrt(-1.0).is_nan());  in spec_tests()
261         assert!(sqrt(NAN).is_nan());  in spec_tests()
263             assert_eq!(sqrt(f), f);  in spec_tests()
278             let bits = f64::to_bits(sqrt(values[i]));  in conformance_tests()