Floor () [C language library function source code]

[C language library function source code]

[This program is compiled in Dev C ++ 4.9.9.2]

Double my_floor (Double X)

{

Register double ret;

Unsigned short int temp1, temp2;

 

_ ASM _ ("fnstcw % 0": "= m" (temp1 ));

Temp2 = (temp1 & 0xf3ff) | 0x0400;/* rounding down */

_ ASM _ ("fldcw % 0": "M" (temp2 ));

_ ASM _ ("frndint": "= T" (RET): "0" (x ));

_ ASM _ ("fldcw % 0": "M" (temp1 ));

 

Return ret;

} // Round down

// The following is the rounded down function written by myself.

Double my_floor01 (Double X)

{

Double Y = X;

If (* (int *) & Y) + 1) & 0x80000000 )! = 0) // or if (x <0)

Return (float) (INT) x)-1;

Else

Return (float) (INT) X );

}

Int main ()

{

Double A = 88.8;

Printf ("floor (% F) = % F/N", A, my_floor ());

A =-88.8;

Printf ("floor (% F) = % F/N", A, my_floor ());

Printf ("****************************/N ");

A = 88.8;

Printf ("floor (% F) = % F/N", A, my_floor01 ());

A =-88.8;

Printf ("floor (% F) = % F/N", A, my_floor01 ());

 

System ("pause ");

Return 0;

}