path: root/arch/m68k/fpsp040/do_func.S

|
|	do_func.sa 3.4 2/18/91
|
| Do_func performs the unimplemented operation.  The operation
| to be performed is determined from the lower 7 bits of the
| extension word (except in the case of fmovecr and fsincos).
| The opcode and tag bits form an index into a jump table in
| tbldo.sa.  Cases of zero, infinity and NaN are handled in
| do_func by forcing the default result.  Normalized and
| denormalized (there are no unnormalized numbers at this
| point) are passed onto the emulation code.
|
| CMDREG1B and STAG are extracted from the fsave frame
| and combined to form the table index.  The function called
| will start with a0 pointing to the ETEMP operand.  Dyadic
| functions can find FPTEMP at -12(a0).
|
| Called functions return their result in fp0.  Sincos returns
| sin(x) in fp0 and cos(x) in fp1.
|

|		Copyright (C) Motorola, Inc. 1990
|			All Rights Reserved
|
|       For details on the license for this file, please see the
|       file, README, in this same directory.

DO_FUNC:	|idnt    2,1 | Motorola 040 Floating Point Software Package

	|section	8

#include "fpsp.h"

	|xref	t_dz2
	|xref	t_operr
	|xref	t_inx2
	|xref	t_resdnrm
	|xref	dst_nan
	|xref	src_nan
	|xref	nrm_set
	|xref	sto_cos

	|xref	tblpre
	|xref	slognp1,slogn,slog10,slog2
	|xref	slognd,slog10d,slog2d
	|xref	smod,srem
	|xref	sscale
	|xref	smovcr

PONE:	.long	0x3fff0000,0x80000000,0x00000000	|+1
MONE:	.long	0xbfff0000,0x80000000,0x00000000	|-1
PZERO:	.long	0x00000000,0x00000000,0x00000000	|+0
MZERO:	.long	0x80000000,0x00000000,0x00000000	|-0
PINF:	.long	0x7fff0000,0x00000000,0x00000000	|+inf
MINF:	.long	0xffff0000,0x00000000,0x00000000	|-inf
QNAN:	.long	0x7fff0000,0xffffffff,0xffffffff	|non-signaling nan
PPIBY2:  .long	0x3FFF0000,0xC90FDAA2,0x2168C235	|+PI/2
MPIBY2:  .long	0xbFFF0000,0xC90FDAA2,0x2168C235	|-PI/2

	.global	do_func
do_func:
	clrb	CU_ONLY(%a6)
|
| Check for fmovecr.  It does not follow the format of fp gen
| unimplemented instructions.  The test is on the upper 6 bits;
| if they are $17, the inst is fmovecr.  Call entry smovcr
| directly.
|
	bfextu	CMDREG1B(%a6){#0:#6},%d0 |get opclass and src fields
	cmpil	#0x17,%d0		|if op class and size fields are $17,
|				;it is FMOVECR; if not, continue
	bnes	not_fmovecr
	jmp	smovcr		|fmovecr; jmp directly to emulation

not_fmovecr:
	movew	CMDREG1B(%a6),%d0
	andl	#0x7F,%d0
	cmpil	#0x38,%d0		|if the extension is >= $38,
	bge	serror		|it is illegal
	bfextu	STAG(%a6){#0:#3},%d1
	lsll	#3,%d0		|make room for STAG
	addl	%d1,%d0		|combine for final index into table
	leal	tblpre,%a1	|start of monster jump table
	movel	(%a1,%d0.w*4),%a1	|real target address
	leal	ETEMP(%a6),%a0	|a0 is pointer to src op
	movel	USER_FPCR(%a6),%d1
	andl	#0xFF,%d1		| discard all but rounding mode/prec
	fmovel	#0,%fpcr
	jmp	(%a1)
|
|	ERROR
|
	.global	serror
serror:
	st	STORE_FLG(%a6)
	rts
|
| These routines load forced values into fp0.  They are called
| by index into tbldo.
|
| Load a signed zero to fp0 and set inex2/ainex
|
	.global	snzrinx
snzrinx:
	btstb	#sign_bit,LOCAL_EX(%a0)	|get sign of source operand
	bnes	ld_mzinx	|if negative, branch
	bsr	ld_pzero	|bsr so we can return and set inx
	bra	t_inx2		|now, set the inx for the next inst
ld_mzinx:
	bsr	ld_mzero	|if neg, load neg zero, return here
	bra	t_inx2		|now, set the inx for the next inst
|
| Load a signed zero to fp0; do not set inex2/ainex
|
	.global	szero
szero:
	btstb	#sign_bit,LOCAL_EX(%a0) |get sign of source operand
	bne	ld_mzero	|if neg, load neg zero
	bra	ld_pzero	|load positive zero
|
| Load a signed infinity to fp0; do not set inex2/ainex
|
	.global	sinf
sinf:
	btstb	#sign_bit,LOCAL_EX(%a0)	|get sign of source operand
	bne	ld_minf			|if negative branch
	bra	ld_pinf
|
| Load a signed one to fp0; do not set inex2/ainex
|
	.global	sone
sone:
	btstb	#sign_bit,LOCAL_EX(%a0)	|check sign of source
	bne	ld_mone
	bra	ld_pone
|
| Load a signed pi/2 to fp0; do not set inex2/ainex
|
	.global	spi_2
spi_2:
	btstb	#sign_bit,LOCAL_EX(%a0)	|check sign of source
	bne	ld_mpi2
	bra	ld_ppi2
|
| Load either a +0 or +inf for plus/minus operand
|
	.global	szr_inf
szr_inf:
	btstb	#sign_bit,LOCAL_EX(%a0)	|check sign of source
	bne	ld_pzero
	bra	ld_pinf
|
| Result is either an operr or +inf for plus/minus operand
| [Used by slogn, slognp1, slog10, and slog2]
|
	.global	sopr_inf
sopr_inf:
	btstb	#sign_bit,LOCAL_EX(%a0)	|check sign of source
	bne	t_operr
	bra	ld_pinf
|
|	FLOGNP1
|
	.global	sslognp1
sslognp1:
	fmovemx (%a0),%fp0-%fp0
	fcmpb	#-1,%fp0
	fbgt	slognp1
	fbeq	t_dz2		|if = -1, divide by zero exception
	fmovel	#0,%FPSR		|clr N flag
	bra	t_operr		|take care of operands < -1
|
|	FETOXM1
|
	.global	setoxm1i
setoxm1i:
	btstb	#sign_bit,LOCAL_EX(%a0)	|check sign of source
	bne	ld_mone
	bra	ld_pinf
|
|	FLOGN
|
| Test for 1.0 as an input argument, returning +zero.  Also check
| the sign and return operr if negative.
|
	.global	sslogn
sslogn:
	btstb	#sign_bit,LOCAL_EX(%a0)
	bne	t_operr		|take care of operands < 0
	cmpiw	#0x3fff,LOCAL_EX(%a0) |test for 1.0 input
	bne	slogn
	cmpil	#0x80000000,LOCAL_HI(%a0)
	bne	slogn
	tstl	LOCAL_LO(