m68k/fpsp040/bindec.S

12 |		value in memory; d0 contains the k-factor sign-extended
13 |		to 32-bits.  The input may be either normalized,
18 |	Saves and Modifies: D2-D7,A2,FP2
23 |		The k-factor is saved for use in d7. Clear the
31 |		ILOG is the log base 10 of the input value.  It is
45 |		k-factor can dictate either the total number of digits,
53 |		SCALE is equal to 10^ISCALE, where ISCALE is the number
57 |		10^^(abs(ISCALE)) using a rounding mode which is a
64 |		only one rounding error.  The grs bits are collected in
67 |	A9.	Scale X -> Y.
74 |		compensated for by 'or-ing' in the INEX2 flag to
87 |		or less than LEN -1 digits, adjust ILOG and repeat from
89 |		result is exactly 10^LEN, decrement ILOG and divide
90 |		the mantissa by 10.
95 |		to be a fraction; i.e. (mantissa)/10^LEN and adjusted
106 |	A16.	Write sign bits to final string.
114 |		d2: upper 32-bits of mantissa for binstr
115 |		d3: scratch;lower 32-bits of mantissa for binstr
119 |		d7: k-factor
165 	moveml	%d2-%d7/%a2,-(%a7)
166 	fmovemx %fp0-%fp2,-(%a7)
169 |     The k-factor is saved for use in d7.  Clear BINDEC_FLG for
177 	movel	%d0,%d7		|move k-factor to d7
180 	andiw	#0xe000,%d0	|isolate stag bits
217 |     ILOG is the log base 10 of the input value.  It is approx-
224 |	d0: k-factor/exponent
230 |	d7: k-factor/Unchanged
244 	movel	#-4933,%d6	|force ILOG = -4933
266 	fmovel	#0,%FPSR		|zero all of fpsr - nothing needed
277 |     LEN is the number of digits to be displayed.  The k-factor
293 |	d7: k-factor/Unchanged
307 	bles	k_neg		|if k <= 0, LEN = ILOG + 1 - k
329 |     SCALE is equal to 10^ISCALE, where ISCALE is the number
332 |     of ISCALE, used in A9.  Fp1 contains 10^^(abs(ISCALE)) using
339 |	----------------------------------------------
346 |	 RZ	01	   1	   0		10/2	RM
347 |	 RZ	01	   1	   1		10/2	RM
348 |	 RM	10	   0	   0		11/3	RP
349 |	 RM	10	   0	   1		10/2	RM
350 |	 RM	10	   1	   0		10/2	RM
351 |	 RM	10	   1	   1		11/3	RP
352 |	 RP	11	   0	   0		10/2	RM
355 |	 RP	11	   1	   1		10/2	RM
359 |	d0: exponent/scratch - final is 0
361 |	d3: x/scratch - offset ptr into PTENRM array
365 |	d7: k-factor/Unchanged
370 |	fp1: x/10^ISCALE
380 	cmpl	%d6,%d7		|test k - ILOG
384 	movel	%d6,%d0		|calc ILOG + 1 - LEN in d0
393 	cmpl	#0xffffecd4,%d0	|test iscale <= -4908
401 	bfextu	USER_FPCR(%a6){#26:#2},%d1 |get initial rmode bits
402 	lslw	#1,%d1		|put them in bits 2:1
404 	lslw	#1,%d1		|put them in bits 3:1
411 	lsll	#4,%d3		|put bits in proper position
412 	fmovel	%d3,%fpcr		|load bits into fpu
413 	lsrl	#4,%d3		|put bits in proper position
430 	fmulx	(%a1,%d3),%fp1	|mul by 10**(d3_bit_no)
440 |     only one rounding error.  The grs bits are collected in
450 | A9. Scale X -> Y.
453 |     Check d2 for excess 10 exponential value.  If not zero,
456 |     multiply by 10^(d2), which is now only allowed to be 24,
457 |     with a multiply by 10^8 and 10^16, which is exact since
458 |     10^24 is exact.  If the input was denormalized, we must
470 |	d7: k-factor/Unchanged
475 |	fp1: 10^ISCALE/Unchanged
487 	fdivx	%fp1,%fp0		|calculate X / SCALE -> Y to fp0
493 	fmovemx %fp1-%fp1,-(%a7)	|load ETEMP with 10^ISCALE
494 	movel	8(%a0),-(%a7)	|load FPTEMP with input arg
495 	movel	4(%a0),-(%a7)
496 	movel	(%a0),-(%a7)
499 	clrl	-(%a7)		|clear lword on stack
502 	moveb	#BUSY_SIZE-4,1(%a7) |write current busy size
507 	fmulx	36(%a1),%fp0	|multiply fp0 by 10^8
508 	fmulx	48(%a1),%fp0	|multiply fp0 by 10^16
513 	fmulx	36(%a1),%fp0	|multiply fp0 by 10^8
514 	fmulx	48(%a1),%fp0	|multiply fp0 by 10^16
516 	fmulx	%fp1,%fp0		|calculate X * SCALE -> Y to fp0
521 |      for by 'or-ing' in the INEX2 flag to the lsb of Y.
531 |	d7: k-factor/Unchanged
536 |	fp1: 10^ISCALE/Unchanged
572 |	d7: k-factor/Unchanged
576 |	a6: temp pointer to FP_SCR2(a6) - orig value saved and restored
578 |	fp1: 10^ISCALE/Unchanged
586 	moveml	%d0-%d1/%a0-%a1,-(%a7)	|save regs used by sintd0
587 	movel	L_SCR1(%a6),-(%a7)
588 	movel	L_SCR2(%a6),-(%a7)
593 	orl	#0x80000000,(%a0)		|if neg, use -Y
595 	movel	USER_FPSR(%a6),-(%a7)
601 	moveml	(%a7)+,%d0-%d1/%a0-%a1	|restore regs used by sint
608 |      or less than LEN -1 digits, adjust ILOG and repeat from
610 |      result is exactly 10^LEN, decrement ILOG and divide
611 |      the mantissa by 10.  The calculation of 10^LEN cannot
612 |      be inexact, since all powers of ten up to 10^27 are exact
613 |      in extended precision, so the use of a previous power-of-ten
625 |	d7: k-factor/Unchanged
630 |	fp1: 10^ISCALE/Unchanged
631 |	fp2: x/10^LEN
640 	bne	not_zr		|if non-zero, go to second test
642 | Compute 10^(LEN-1)
646 	subql	#1,%d0		|d0 = LEN -1
651 	fmulx	(%a1,%d3),%fp2	|mul by 10**(d3_bit_no)
657 | 10^LEN-1 is computed for this test and A14.  If the input was
658 | denormalized, check only the case in which YINT > 10^LEN.
665 | Compare abs(YINT) to 10^(LEN-1) and 10^LEN
669 	fcmpx	%fp2,%fp0		|compare abs(YINT) with 10^(LEN-1)
674 	fmuls	FTEN,%fp2	|compute 10^LEN
677 	fmuls	FTEN,%fp2	|compute 10^LEN
678 	fcmpx	%fp2,%fp0		|compare abs(YINT) with 10^LEN
681 	fdivs	FTEN,%fp0	|if equal, divide by 10
691 | and shouldn't have another; this is to check if abs(YINT) = 10^LEN
692 | 10^LEN is again computed using whatever table is in a1 since the
702 	fmulx	(%a1,%d3),%fp2	|mul by 10**(d3_bit_no)
708 	fcmpx	%fp2,%fp0		|check if abs(YINT) = 10^LEN
710 	fdivs	FTEN,%fp0	|divide abs(YINT) by 10
713 	fmuls	FTEN,%fp2	| if LEN++, the get 10^^LEN
719 |      to be a fraction; i.e. (mantissa)/10^LEN and adjusted
727 |	d0: x/LEN call to binstr - final is 0
729 |	d2: x/ms 32-bits of mant of abs(YINT)
730 |	d3: x/ls 32-bits of mant of abs(YINT)
734 |	d7: k-factor/Unchanged
740 |	fp1: 10^ISCALE/Unchanged
741 |	fp2: 10^LEN/Unchanged
749 	fdivx	%fp2,%fp0		|divide abs(YINT) by 10^LEN
751 	fmovex	%fp0,(%a0)	|move abs(YINT)/10^LEN to memory
790 |	-----------------------------------------
792 |	-----------------------------------------
795 | is non-zero, OPERR is signaled.  In all cases, all 4 digits are
800 |	d0: x/LEN call to binstr - final is 0
802 |	d2: x/ms 32-bits of exp fraction/scratch
803 |	d3: x/ls 32-bits of exp fraction
807 |	d7: k-factor/Unchanged
812 |	fp1: 10^ISCALE/Unchanged
813 |	fp2: 10^LEN/Unchanged
815 |	F_SCR2:Y with original exponent/ILOG/10^4
823 	fbeq	den_zero	|if zero, use k-factor or 4933
828 	tstl	%d7		|check sign of the k-factor
845 	fdivx	24(%a1),%fp0	|compute ILOG/10^4
876 | A16. Write sign bits to final string.
881 |	d0: x/scratch - final is x
887 |	d7: k-factor/Unchanged
892 |	fp1: 10^ISCALE/Unchanged
893 |	fp2: 10^LEN/Unchanged
895 |	F_SCR2:ILOG/10^4
914 	fmovel	#0,%FPSR		|clear possible inex2/ainex bits
915 	fmovemx (%a7)+,%fp0-%fp2
916 	moveml	(%a7)+,%d2-%d7/%a2