ttl ieee format equivalent exponent (iefexp) *************************************** * (c) copyright 1981 by motorola inc. * *************************************** ************************************************* * iefexp * * ieee format equivalent exponent function * * * * input: d7 - ieee floating point argument * * * * output: d7 - ieee floating point exponential* * result * * * * all other registers are transparent * * * * maximum stack used: 54 bytes * * * * condition codes: * * z - set if result in d7 is zero * * n - cleared * * v - set if result is nan (not-a-number)* * c - undefined * * x - undefined * * * * * * notes: * * 1) if the input argument is a nan (not-a- * * number) then the "v" bit will be set * * and the argument unchanged upon return. * * 2) see the mc68344 user's guide for details* * on the range of ieee normalized values * * supported. * * 2) spot checks show at least 6.8 digit * * accuracy for all abs(arg) < 30. * * * ************************************************* page iefexp idnt 1,1 ieee format equivalent exp opt pcs section 9 xdef iefexp entry point xref ffpexp fast floating point exponent xref iefsop front-end single argument routine xref ieftieee back-end return to ieee format xref iefrtd7 return to caller argument in d7 xref ffpcpyrt copyright stub ************************ * exponent entry point * ************************ iefexp bsr iefsop convert argument to ffp format bra.s iefnrm branch normalized * argument is an infinity bpl.s iefdrtn branch if plus - return itself move.l #0,d7 return plus zero if was negative infinity iefdrtn bra iefrtd7 return the result that is in d7 * argument is normalized iefnrm bsr ffpexp call fast floating point exponent function bra ieftieee and return in ieee format end