m68k/fpsp040/bindec.S

7 |		Converts an input in extended precision format
12 |		value in memory; d0 contains the k-factor sign-extended
16 |	Output:	result in the FP_SCR1 space on the stack.
23 |		The k-factor is saved for use in d7. Clear the
33 |		value is viewed as 2^^e * 1.f in extended precision.
34 |		This value is stored in d6.
37 |		The operation in A3 above may have set INEX2.
40 |		ICTR is a flag used in A13.  It must be set before the
49 |		If LEN is computed to be greater than 17, set OPERR in
50 |		USER_FPSR.  LEN is stored in d4.
55 |		in the output before conversion to bcd. LAMBDA is the
56 |		sign of ISCALE, used in A9. Fp1 contains
59 |		of ISCALE and X.  A table is given in the code.
62 |		The operation in A3 above may have set INEX2.
64 |		only one rounding error.  The grs bits are collected in
65 |		the INEX flag for use in A10.
70 |		in INEX2.
72 |	A10.	Or in INEX.
74 |		compensated for by 'or-ing' in the INEX2 flag to
78 |		Perform FINT operation in the user's rounding mode.
83 |		is in fp0.
86 |		If the int operation results in more than LEN digits,
94 |		mantissa to bcd in memory.  The input to binstr is
97 |		The bcd digits are stored in the correct position in
98 |		the final string area in memory.
101 |		As in A14 above, the exp is converted to bcd and the
102 |		digits are stored in the final string.
122 |		a2: pointer to FP_X; abs(original value) in ext
135 |       file, README, in this same directory.
143 | Constants in extended precision
147 | Constants in single precision
169 |     The k-factor is saved for use in d7.  Clear BINDEC_FLG for
219 |     as 2^^e * 1.f in extended precision.  This value is stored
220 |     in d6.
251 	faddw	%d0,%fp0		|add in exp
255 	fmovel	%fp0,%d6		|put ILOG in d6 as a lword
259 	fmovel	%fp0,%d6		|put ILOG in d6 as a lword
263 |     The operation in A3 above may have set INEX2.
270 |     ICTR is a flag used in A13.  It must be set before the
282 |     If LEN is computed to be greater than 17, set OPERR in
283 |     USER_FPSR.  LEN is stored in d4.
313 	addql	#1,%d4		|add in the 1
322 	orl	#opaop_mask,USER_FPSR(%a6) |set OPERR & AIOP in USER_FPSR
331 |     in the output before conversion to bcd. LAMBDA is the sign
332 |     of ISCALE, used in A9.  Fp1 contains 10^^(abs(ISCALE)) using
333 |     the rounding mode as given in the following table (see
335 |     of opposite sign in bindec.sa from Coonen).
384 	movel	%d6,%d0		|calc ILOG + 1 - LEN in d0
395 	addil	#24,%d0		|add in 24 to iscale
396 	movel	#24,%d2		|put 24 in d2 for A9
402 	lslw	#1,%d1		|put them in bits 2:1
403 	addw	%d5,%d1		|add in LAMBDA
404 	lslw	#1,%d1		|put them in bits 3:1
411 	lsll	#4,%d3		|put bits in proper position
413 	lsrl	#4,%d3		|put bits in proper position
419 	lsrb	#1,%d3		|get lsb in carry
438 |     The operation in A3 above may have set INEX2.
440 |     only one rounding error.  The grs bits are collected in
441 |     the INEX flag for use in A10.
452 |     digits.  The excess digits are collected in INEX2. If mul,
485 	tstw	%d5		|LAMBDA is in lower word of d5
519 | A10. Or in INEX.
521 |      for by 'or-ing' in the INEX2 flag to the lsb of Y.
545 	oril	#1,8(%a2)	|or in 1 to lsb of mantissa
550 |      Perform FINT operation in the user's rounding mode.  Keep
551 |      the size to extended.  The sintdo entry point in the sint
552 |      routine expects the FPCR value to be in USER_FPCR for
553 |      mode and precision.  The original FPCR is saved in L_SCR1.
562 |      The FPSP routine sintd0 is used.  The output is in fp0.
596 	bsr	sintdo			|sint routine returns int in fp0
607 |      If the int operation results in more than LEN digits,
613 |      in extended precision, so the use of a previous power-of-ten
638 	swap	%d5		|put ICTR in lower word of d5
645 	movel	%d4,%d0		|put LEN in d0
658 | denormalized, check only the case in which YINT > 10^LEN.
692 | 10^LEN is again computed using whatever table is in a1 since the
697 	movel	%d4,%d0		|put LEN in d0
718 |      mantissa to bcd in memory.  The input to binstr is
721 |      The bcd digits are stored in the correct position in
722 |      the final string area in memory.
736 |	    /ptr to first mantissa byte in result string
757 	swap	%d0		|put exponent in lower word
766 	dbf	%d0,m_loop	|given in d0
773 	clrl	%d1		|put zero in d1 for addx
778 	movel	%d4,%d0		|put LEN in d0 for binstr call
779 	addql	#3,%a0		|a0 points to M16 byte in result
784 |      As in A14 above, the exp is converted to bcd and the
785 |      digits are stored in the final string.
787 |      Digits are stored in L_SCR1(a6) on return from BINDEC as:
794 | And are moved into their proper places in FP_SCR1.  If digit e4
796 | written as specified in the 881/882 manual for packed decimal.
846 	fmovex	%fp0,FP_SCR2(%a6)	|store fp0 in memory
856 	dbf	%d0,x_loop	|given in d0
858 	clrl	%d1		|put zero in d1 for addx
862 	movel	#4,%d0		|put 4 in d0 for binstr call
868 	bfins	%d0,FP_SCR1(%a6){#4:#12} |put e3:e2:e1 in FP_SCR1
870 	bfins	%d0,FP_SCR1(%a6){#16:#4} |put e4 in FP_SCR1
873 	orl	#opaop_mask,USER_FPSR(%a6) |set OPERR & AIOP in USER_FPSR
904 	moveql	#2,%d0		|move 2 in to d0 for SM
908 	addql	#1,%d0		|set bit 0 in d0 for SE