m68k/fpsp040/decbin.S

5 |	register A6 to extended-precision value in FP0.
9 |	Output:	Exact floating-point representation of the packed bcd value.
11 |	Saves and Modifies: D2-D5
20 |	Expected is a normal bcd (i.e. non-exceptional; all inf, zero,
33 |	assumed following the least-significant digit.
43 |	SM = 0	a non-zero digit in the integer position
44 |	SM = 1	a non-zero digit in Mant0, lsd of the fraction
47 |	representation (ex. 0.1E2, 1E1, 10E0, 100E-1), is converted
62 |	Clean up and return.  Check if the final mul or div resulted
85 |	is required until the power is greater than 27, however, all
121 	moveml	%d2-%d5,-(%a7)
145 	moveql	#ESTRT,%d3	|counter to pick up digits
196 |  get the integer digit then skip down & get the rest of the
207 	moveql	#FSTRT,%d3	|counter to pick up digits
248 |   3. Add one for each zero encountered until a non-zero digit.
255 |   3. Add one for each zero encountered until a non-zero digit.
260 |  *Why 27?  If the adjusted exponent is within -28 < expA < 28, than
262 |   exponent towards zero.  Since all pwrten constants with a power
282 | and do append (+) or strip (-) zeros accordingly.
288 	ble	pwrten		|if abs(expA) <28, skip ap/st zeros
294 	bnes	ap_p_fx		|if M16 is non-zero, go fix exp
298 	bnes	ap_p_cl		|if lw 2 is zero, skip it
307 	bnes	ap_p_fx		|if non-zero, go to fix exp
325 	movel	#PTENRN,%a1	|get address of power-of-ten table
344 	moveql	#2,%d5		|set up d5 to point to lword 3
355 	bnes	ap_n_fx		|if non-zero, go to exp fix
373 	movel	#PTENRN,%a1	|get address of power-of-ten table
388 | Calculate power-of-ten factor from adjusted and shifted exponent.
405 |	(*) fp1: power-of-ten accumulator
415 |	 -	   +	RP	RM
416 |	 +	   -	RP	RM
417 |	 -	   -	RP	RP
420 |	 -	   +	RM	RP
421 |	 +	   -	RM	RP
422 |	 -	   -	RM	RM
425 |	 -	   +	RZ	RM
426 |	 +	   -	RZ	RP
427 |	 -	   -	RZ	RP
463 	bccs	e_next		|if zero, skip the mul
479 |	( ) fp1: scaling factor - 10**(abs(exp))
491 | Clean up and return with result in fp0.
500 	beqs	no_exc		|skip this if no exc
503 	moveml	(%a7)+,%d2-%d5