s16 shl(s16 var1,s16 var2) { s16 var_out; s32 resultat; if (var2 < 0) { var2 = -var2; var_out = shr(var1,var2); } else { resultat = (s32) var1 * ((s32) 1 << var2); if ((var2 > 15 && var1 != 0) || (resultat != (s32)((s16) resultat))) { gOverflow_flag = 1; var_out = (var1 > 0) ? MAX_16 : MIN_16; } else { var_out = extract_l(resultat); } } return(var_out); }

The function shl takes two arguments var1 and var2 and returns the result of shifting var1 by var2 bits to the left.