Motorola DSP96002 - Manual (Page 673)

B-154 DSP96002 USER’S MANUAL MOTOROLA
and d7,d2 ; remove implied one bit
tst d2 ; check m0.high = zero
jne _nan0 ; jump if nan
tst d0 ; check m0.low = zero
jne _nan0 ; jump if nan
move #emsk,d7.l ; get exponent mask
move d1.h,d5.l ; get exp1
and d7,d5 ; delete tags
cmp d7,d5 ; check for max exp
jne _inf1 ; jump if a1 is not inf or NaN
;
; Check if Addend 1 is Infinity
;
_mant2 move #imsk,d7.l ; get infinity mask
and d7,d3 ; remove implied one bit
tst d3 ; check m1.high = zero
jne _nan1 ; jump if nan
tst d1 ; check m1.low = zero
jne _nan1 ; jump if nan
jclr #0,d6.l,_binf ; jump if a0 and a1 are inf
ori #$10,ccr ; set infinity bit
jmp _done ; a1 is infinity
;
; Check for Case: (+Inf) + (-Inf) = QNaN
;
_inf1 ftfr.x d0,d1 ; move result to d1
ori #$10,ccr ; set infinity bit
jmp _done ; a0 is infinity
_binf ftst d0 ; check sign of a0
jmi _minf ; jump if a0 is -inf
ftst d1 ; check sign of a1
jmi _inan ; (+inf) + (-inf) = QNaN
ori #$10,ccr ; set infinity bit
jmp _done ; a0 and a1 are +inf
_minf ftst d1 ; check sign of a1
jpl _inan ; (-inf) + (+inf) = QNaN
ori #$10,ccr ; set infinity bit
jmp _done ; a0 and a1 are -inf
;
; Check for NaNs
;
_nan0 jclr #30,d0.m,_inan ; jump if a0 is a SNaN
move #emsk,d7.l ; get exponent mask
move d1.h,d5.l ; get exp1
and d7,d5 ; delete tags
cmp d7,d5 ; check for max exp
jne _qnan ; jump if a1 is not a NaN
move #imsk,d7.l ; get infinity mask
and d7,d3 ; remove implied one bit
tst d3 ; check mant1.high = zero
jne _nan1 ; jump if a1 is a NaN
tst d1 ; check mant1.low = zero
jeq _qnan ; jump if a1 is infinity
_nan1 jset #30,d1.m,_qnan ; jump if a1 is a QNaN