m68k/fpsp040/res_func.S

112 | destination precision and mode.
115 	st	CU_ONLY(%a6)		|set cu-only inst flag
179 | and bit 6 is set, round is forced to single.  If both are clear,
180 | the round precision is found in the fpcr.  If the rounding precision
181 | is double or single, round the result before the write.
192 | The move or operation is not with forced precision.  Test for
200 	cmpib	#1,%d0			|check for single
203 | The move is fdmove or round precision is double.
227 | The move is fsmove or round precision is single.
250 | The operand is above precision boundaries.  Use t_ovfl to
257 | The operand is below precision boundaries.  Use denorm to
323 	orl	#0x100,LOCAL_HI(%a0) |inc for single
383 	st	CU_ONLY(%a6)	|set cu-only inst flag
403 |				;wrap-around case
414 | cu_dnrm handles all cu-only instructions (fmove, fabs, fneg, and
475 | and bit 6 is set, round is forced to single.  If both are clear,
476 | the round precision is found in the fpcr.  If the rounding precision
477 | is double or single, the result is zero, and the mode is checked
486 | The move or operation is not with forced precision.  Use the
493 	cmpib	#1,%d0			|check for single
496 | The move is fdmove or round precision is double.  Result is zero.
511 | The move is fsmove or round precision is single.  Result is zero.
519 	bne	cu_spd			|load single pos zero
520 	bra	cu_spdr			|load single pos zero w/lsb
523 	bne	cu_snd			|load single neg zero
524 	bra	cu_sndr			|load single neg zero w/lsb
526 | The precision is extended, so the result in etemp is correct.
536 | These routines write +/- zero in double format.  The routines
568 | These routines write +/- zero in single format.  The routines
569 | cu_dpdr and cu_dndr set the single lsb.
572 	movel	#0x3f810000,LOCAL_EX(%a0)	|force pos single zero
579 	movel	#0x3f810000,LOCAL_EX(%a0)	|force pos single zero
585 	movel	#0xbf810000,LOCAL_EX(%a0)	|force pos single zero
593 	movel	#0xbf810000,LOCAL_EX(%a0)	|force pos single zero
601 | This code checks for 16-bit overflow conditions on dyadic
602 | operations which are not restorable into the floating-point
614 | The wrap-around condition occurs for add, sub, div, and cmp
617 |	abs(dest_exp - src_exp) >= $8000
636 |	call round with user's precision and mode
646 |	call round with user's precision and mode
736 	moveql	#-1,%d0
766 	btstl	#6,%d0			|test for forced precision
770 	movel	#0x1,%d0			|inst is forced single
776 	bfextu	FPCR_MODE(%a6){#0:#2},%d0	|inst not forced - use fpcr prec
787 |					;round precision/mode.  This
827 | precision.  We can then call round with no sticky and the result
828 | will be correct for the user's rounding mode and precision.  If
831 | precision.
846 	orw	#0x3fff,%d0	|force the exponent to +/- 1
860 	lsrl	#6,%d1		|put precision in upper word
874 	orw	#0x3fff,%d0	|force the exponent to +/- 1
888 	lsrl	#6,%d1		|put precision in upper word
912 	lsrl	#6,%d1		|put precision in upper word
938 	lsrl	#6,%d1		|put precision in upper word
1002 | precision.  We can then call round with no sticky and the result
1003 | will be correct for the user's rounding mode and precision.  If
1006 | precision.
1021 	orw	#0x3fff,%d0	|force the exponent to +/- 1
1035 	lsrl	#6,%d1		|put precision in upper word
1049 	orw	#0x3fff,%d0	|force the exponent to +/- 1
1063 	lsrl	#6,%d1		|put precision in upper word
1087 	lsrl	#6,%d1		|put precision in upper word
1119 	lsrl	#6,%d1		|put precision in upper word
1234 	btstl	#6,%d0			|test for forced precision
1238 	movel	#0x1,%d0			|inst is forced single
1244 	bfextu	FPCR_MODE(%a6){#0:#2},%d0	|inst not forced - use fpcr prec
1247 |					;round precision/mode.  This
1257 | If the rounding precision is single or double, the ovf_res routine
1262 	btstl	#6,%d0			|test for forced precision
1266 	movel	#0x1,%d0			|inst is forced single
1272 	bfextu	FPCR_MODE(%a6){#0:#2},%d0	|inst not forced - use fpcr prec
1279 |					;round precision/mode.  This
1292 	bles	frc0123			|check if dest is fp0-fp3
1379 	bles	fp0123			|check if dest is fp0-fp3
1444 | This exit is for move-out to memory.  The aunfl bit is
1468 | This exit is for move-out to int register.  The aunfl bit is
1495 	fmovemx ETEMP(%a6),%fp0-%fp0
1540 	fmovemx ETEMP(%a6),%fp0-%fp0
1585 	fmovemx ETEMP(%a6),%fp0-%fp0
1623 | int_drnrm---account for possible nonzero result for round up with positive
1625 | byte-width (store in d0) of result must be honored.  In the second case,
1626 | -1 in L_SCR1(a6) will cover all contingencies (FMOVE.B/W/L out).
1634 	tstw	ETEMP(%a6)	| RM: store -1 in L_SCR1 if src is negative
1636 	movel	#-1,L_SCR1(%a6)
1643 	addal	%d0,%a1		| offset by destination width -1
1650 	fmovemx %fp0-%fp0,FPTEMP(%a6)	|FPTEMP must contain the extended
1651 |				;precision source that needs to be
1667 	movel	%d0,-(%sp)	|d0 currently contains the size to write
1703 	movel	#1,%d0		|set destination format to single
1741 	bgts	ddbl			|double=5, extended=2, single=1
1773 	movel	#1,%d0		|load in round precision
1774 	movel	#sgl_thresh,%d1	|load in single denorm threshold
1787 	movel	#dbl_thresh,%d1	|load in double precision threshold
1791 |				;expects d0 to have round precision
1801 	movel	USER_FPSR(%a6),-(%a7)
1803 	movel	#1,%d0		|set round precision to sgl
1822 	movel	USER_FPSR(%a6),-(%a7)
1824 	movel	#2,%d0		|set round precision to dbl
1845 	movel	USER_FPSR(%a6),-(%a7)
1864 	movel	USER_FPSR(%a6),-(%a7)
1885 | it to the given round precision. This subroutine also decrements
1890 |	 d0  is the round precision (=1 for sgl; =2 for dbl)
1891 |	 d1  is the single precision or double precision
1901 	movel	%d0,-(%a7)	|save round precision
1907 	movew	2(%a7),%d1	|set rounding precision
1967 | Also note that the dtag must be set to norm here - this is because
1975 |	1. Operr is not signalled if the k-factor is greater than 18.
1981 	btstl	#kfact_bit,%d0	|test for dynamic k-factor
1982 	beqs	statick		|if clear, k-factor is static
1984 	bfextu	%d0{#25:#3},%d0	|isolate register for dynamic k-factor
1989 	andiw	#0x007f,%d0	|get k-factor
2012 | Routines to read the dynamic k-factor from Dn.