Assembly code fsqrt and fmul function : Im trying to compute 1.34 *sqrt(lght) in this function using assembly code, but Im getting errors like 
 '_asm' undeclared (first use in this function)
   each undeclared identifier is reported only once for each func                                                tion it appears in
 expected ';' before '{' token
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I have been researching how to solve this problem but cant find much to continue can you guys help me fix it please ??

       double hullSpeed(double lgth)
       {
       _asm{
       global _start

       fld lght; //load lght
      fld st(0); //duplicate lght on Top of stack
      fsqrt ; square root of lght
      fld st(0);//load square result on top of stack
      fld 1.34;//load 1.34 on top of stack
      fld st(i); duplicate 1.34 on TOS
      fmulp st(0), st(i);//multiply them 
      fst z; save result in z
      }


      return z;// return result of [ 1.34 *sqrt(lght) ]

     }
