musl-tcc/src/math/arm/sqrt.c

#include <math.h>

#if (__ARM_PCS_VFP || (__VFP_FP__ && !__SOFTFP__)) && (__ARM_FP&8)

double sqrt(double x)
{
	__asm__ ("vsqrt.f64 %P0, %P1" : "=w"(x) : "w"(x));
	return x;
}

#else

#include "../sqrt.c"

#endif