* MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP
* M68000 Hi-Performance Microprocessor Division
* M68040 Software Package
*
* M68040 Software Package Copyright (c) 1993, 1994 Motorola Inc.
* All rights reserved.
*
* THE SOFTWARE is provided on an "AS IS" basis and without warranty.
* To the maximum extent permitted by applicable law,
* MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED,
* INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
* PARTICULAR PURPOSE and any warranty against infringement with
* regard to the SOFTWARE (INCLUDING ANY MODIFIED VERSIONS THEREOF)
* and any accompanying written materials.
*
* To the maximum extent permitted by applicable law,
* IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER
* (INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS
* PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR
* OTHER PECUNIARY LOSS) ARISING OF THE USE OR INABILITY TO USE THE
* SOFTWARE. Motorola assumes no responsibility for the maintenance
* and support of the SOFTWARE.
*
* You are hereby granted a copyright license to use, modify, and
* distribute the SOFTWARE so long as this entire notice is retained
* without alteration in any modified and/or redistributed versions,
* and that such modified versions are clearly identified as such.
* No licenses are granted by implication, estoppel or otherwise
* under any patents or trademarks of Motorola, Inc.
*
* 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.
*
DO_FUNC IDNT 2,1 Motorola 040 Floating Point Software Package
xdef do_func
do_func:
clr.b 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
cmpi.l #$17,d0 ;if op class and size fields are $17,
* ;it is FMOVECR; if not, continue
bne.b not_fmovecr
jmp smovcr ;fmovecr; jmp directly to emulation
not_fmovecr:
move.w CMDREG1B(a6),d0
and.l #$7F,d0
cmpi.l #$38,d0 ;if the extension is >= $38,
bge.b short_serror ;it is illegal
bfextu STAG(a6){0:3},d1
lsl.l #3,d0 ;make room for STAG
add.l d1,d0 ;combine for final index into table
lea.l tblpre,a1 ;start of monster jump table
move.l (a1,d0.w*4),a1 ;real target address
lea.l ETEMP(a6),a0 ;a0 is pointer to src op
move.l USER_FPCR(a6),d1
and.l #$FF,d1 ; discard all but rounding mode/prec
fmove.l #0,fpcr
jmp (a1)
*
* ERROR
*
xdef serror
serror:
short_serror:
st.b 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
*
xdef snzrinx
snzrinx:
btst.b #sign_bit,LOCAL_EX(a0) ;get sign of source operand
bne.b 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
*
xdef szero
szero:
btst.b #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
*
xdef sinf
sinf:
btst.b #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
*
xdef sone
sone:
btst.b #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
*
xdef spi_2
spi_2:
btst.b #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
*
xdef szr_inf
szr_inf:
btst.b #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]
*
xdef sopr_inf
sopr_inf:
btst.b #sign_bit,LOCAL_EX(a0) ;check sign of source
bne t_operr
bra ld_pinf
*
* FLOGNP1
*
xdef sslognp1
sslognp1:
fmovem.x (a0),fp0
fcmp.b #-1,fp0
fbgt slognp1
fbeq t_dz2 ;if = -1, divide by zero exception
fmove.l #0,FPSR ;clr N flag
bra t_operr ;take care of operands < -1
*
* FETOXM1
*
xdef setoxm1i
setoxm1i:
btst.b #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.
*
xdef sslogn
sslogn:
btst.b #sign_bit,LOCAL_EX(a0)
bne t_operr ;take care of operands < 0
cmpi.w #$3fff,LOCAL_EX(a0) ;test for 1.0 input
bne slogn
cmpi.l #$80000000,LOCAL_HI(a0)
bne slogn
tst.l LOCAL_LO(a0)
bne slogn
fmove.x PZERO,fp0
rts
xdef sslognd
sslognd:
btst.b #sign_bit,LOCAL_EX(a0)
beq slognd
bra t_operr ;take care of operands < 0
smod_snan:
bra src_nan
smod_dnan:
bra dst_nan
smod_oper:
bra t_operr
smod_zro:
move.b ETEMP(a6),d1 ;get sign of src op
move.b FPTEMP(a6),d0 ;get sign of dst op
eor.b d0,d1 ;get exor of sign bits
btst.l #7,d1 ;test for sign
beq.b smod_zsn ;if clr, do not set sign big
bset.b #q_sn_bit,FPSR_QBYTE(a6) ;set q-byte sign bit
smod_zsn:
btst.l #7,d0 ;test if + or -
beq ld_pzero ;if pos then load +0
bra ld_mzero ;else neg load -0
smod_fpn:
move.b ETEMP(a6),d1 ;get sign of src op
move.b FPTEMP(a6),d0 ;get sign of dst op
eor.b d0,d1 ;get exor of sign bits
btst.l #7,d1 ;test for sign
beq.b smod_fsn ;if clr, do not set sign big
bset.b #q_sn_bit,FPSR_QBYTE(a6) ;set q-byte sign bit
smod_fsn:
tst.b DTAG(a6) ;filter out denormal destination case
bpl.b smod_nrm ;
lea.l FPTEMP(a6),a0 ;a0<- addr(FPTEMP)
bra t_resdnrm ;force UNFL(but exact) result
smod_nrm:
fmove.l USER_FPCR(a6),fpcr ;use user's rmode and precision
fmove.x FPTEMP(a6),fp0 ;return dest to fp0
rts
*
* FREM
*
premt:
* ;$25 frem
* ;dtag,stag
dc.l srem ; 00,00 norm,norm = normal
dc.l srem_oper ; 00,01 norm,zero = nan with operr
dc.l srem_fpn ; 00,10 norm,inf = fpn
dc.l srem_snan ; 00,11 norm,nan = nan
dc.l srem_zro ; 01,00 zero,norm = +-zero
dc.l srem_oper ; 01,01 zero,zero = nan with operr
dc.l srem_zro ; 01,10 zero,inf = +-zero
dc.l srem_snan ; 01,11 zero,nan = nan
dc.l srem_oper ; 10,00 inf,norm = nan with operr
dc.l srem_oper ; 10,01 inf,zero = nan with operr
dc.l srem_oper ; 10,10 inf,inf = nan with operr
dc.l srem_snan ; 10,11 inf,nan = nan
dc.l srem_dnan ; 11,00 nan,norm = nan
dc.l srem_dnan ; 11,01 nan,zero = nan
dc.l srem_dnan ; 11,10 nan,inf = nan
dc.l srem_dnan ; 11,11 nan,nan = nan
xdef prem
prem:
clr.b FPSR_QBYTE(a6) ;clear quotient field
bfextu STAG(a6){0:3},d0 ;stag = d0
bfextu DTAG(a6){0:3},d1 ;dtag = d1
*
* Alias extended denorms to norms for the jump table.
*
bclr #2,d0
bclr #2,d1
srem_snan:
bra src_nan
srem_dnan:
bra dst_nan
srem_oper:
bra t_operr
srem_zro:
move.b ETEMP(a6),d1 ;get sign of src op
move.b FPTEMP(a6),d0 ;get sign of dst op
eor.b d0,d1 ;get exor of sign bits
btst.l #7,d1 ;test for sign
beq.b srem_zsn ;if clr, do not set sign big
bset.b #q_sn_bit,FPSR_QBYTE(a6) ;set q-byte sign bit
srem_zsn:
btst.l #7,d0 ;test if + or -
beq ld_pzero ;if pos then load +0
bra ld_mzero ;else neg load -0
srem_fpn:
move.b ETEMP(a6),d1 ;get sign of src op
move.b FPTEMP(a6),d0 ;get sign of dst op
eor.b d0,d1 ;get exor of sign bits
btst.l #7,d1 ;test for sign
beq.b srem_fsn ;if clr, do not set sign big
bset.b #q_sn_bit,FPSR_QBYTE(a6) ;set q-byte sign bit
srem_fsn:
tst.b DTAG(a6) ;filter out denormal destination case
bpl.b srem_nrm ;
lea.l FPTEMP(a6),a0 ;a0<- addr(FPTEMP)
bra t_resdnrm ;force UNFL(but exact) result
srem_nrm:
fmove.l USER_FPCR(a6),fpcr ;use user's rmode and precision
fmove.x FPTEMP(a6),fp0 ;return dest to fp0
rts
*
* FSCALE
*
pscalet:
* ;$26 fscale
* ;dtag,stag
dc.l sscale ; 00,00 norm,norm = result
dc.l sscale ; 00,01 norm,zero = fpn
dc.l scl_opr ; 00,10 norm,inf = nan with operr
dc.l scl_snan ; 00,11 norm,nan = nan
dc.l scl_zro ; 01,00 zero,norm = +-zero
dc.l scl_zro ; 01,01 zero,zero = +-zero
dc.l scl_opr ; 01,10 zero,inf = nan with operr
dc.l scl_snan ; 01,11 zero,nan = nan
dc.l scl_inf ; 10,00 inf,norm = +-inf
dc.l scl_inf ; 10,01 inf,zero = +-inf
dc.l scl_opr ; 10,10 inf,inf = nan with operr
dc.l scl_snan ; 10,11 inf,nan = nan
dc.l scl_dnan ; 11,00 nan,norm = nan
dc.l scl_dnan ; 11,01 nan,zero = nan
dc.l scl_dnan ; 11,10 nan,inf = nan
dc.l scl_dnan ; 11,11 nan,nan = nan
xdef pscale
pscale:
bfextu STAG(a6){0:3},d0 ;stag in d0
bfextu DTAG(a6){0:3},d1 ;dtag in d1
bclr.l #2,d0 ;alias denorm into norm
bclr.l #2,d1 ;alias denorm into norm
lsl.b #2,d1
or.b d0,d1 ;d1{4:2} = dtag, d1{1:0} = stag
* ;dtag values stag values:
* ;000 = norm 00 = norm
* ;001 = zero 01 = zero
* ;010 = inf 10 = inf
* ;011 = nan 11 = nan
* ;100 = dnrm
*
*
lea.l pscalet,a1 ;load start of jump table
move.l (a1,d1.w*4),a1 ;load a1 with label depending on tag
jmp (a1) ;go to the routine
scl_opr:
bra t_operr
scl_dnan:
bra dst_nan
scl_zro:
btst.b #sign_bit,FPTEMP_EX(a6) ;test if + or -
beq ld_pzero ;if pos then load +0
bra ld_mzero ;if neg then load -0
scl_inf:
btst.b #sign_bit,FPTEMP_EX(a6) ;test if + or -
beq ld_pinf ;if pos then load +inf
bra ld_minf ;else neg load -inf
scl_snan:
bra src_nan
*
* FSINCOS
*
xdef ssincosz
ssincosz:
btst.b #sign_bit,ETEMP(a6) ;get sign
beq.b sincosp
fmove.x MZERO,fp0
bra.b sincoscom
sincosp:
fmove.x PZERO,fp0
sincoscom:
fmovem.x PONE,fp1 ;do not allow FPSR to be affected
bra sto_cos ;store cosine result
xdef ssincosi
ssincosi:
fmove.x QNAN,fp1 ;load NAN
bsr sto_cos ;store cosine result
fmove.x QNAN,fp0 ;load NAN
bra t_operr
xdef ssincosnan
ssincosnan:
move.l ETEMP_EX(a6),FP_SCR1(a6)
move.l ETEMP_HI(a6),FP_SCR1+4(a6)
move.l ETEMP_LO(a6),FP_SCR1+8(a6)
bset.b #signan_bit,FP_SCR1+4(a6)
fmovem.x FP_SCR1(a6),fp1
bsr sto_cos
bra src_nan
*
* This code forces default values for the zero, inf, and nan cases
* in the transcendentals code. The CC bits must be set in the
* stacked FPSR to be correctly reported.
*
***Returns +PI/2
xdef ld_ppi2
ld_ppi2:
fmove.x PPIBY2,fp0 ;load +pi/2
bra t_inx2 ;set inex2 exc
***Returns -PI/2
xdef ld_mpi2
ld_mpi2:
fmove.x MPIBY2,fp0 ;load -pi/2
or.l #neg_mask,USER_FPSR(a6) ;set N bit
bra t_inx2 ;set inex2 exc
***Returns +inf
xdef ld_pinf
ld_pinf:
fmove.x PINF,fp0 ;load +inf
or.l #inf_mask,USER_FPSR(a6) ;set I bit
rts
***Returns -inf
xdef ld_minf
ld_minf:
fmove.x MINF,fp0 ;load -inf
or.l #neg_mask+inf_mask,USER_FPSR(a6) ;set N and I bits
rts
