Format
#include <builtin.h> double _fsqrt(double x);
Language Level: Extension
_fsqrt computes the square root of x using the FSQRT 80387
instruction. Note that this function does not set errno as the
sqrt function does. If you pass a negative value to this
function, an exception is generated.
Note: _fsqrt is a built-in function, which means it is implemented as an inline instruction and has no backing code in the library. For this reason:
Return Value
_fsqrt returns the value of the square
root of x.
Example
This example calculates the square root
of 4.
#include <builtin.h> #include <stdio.h>
int main(void)
{
double x;
x = 4.0;
printf("The square root of %lf is %lf.\n", x, _fsqrt(x));
return 0;
/********************************************************
The output should be:
The square root of 4.000000 is 2.000000. ********************************************************/ }
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sqrt -- Calculate Square Root
<math.h>