|
| - For unnormalized numbers (opclass 0, 2, or 3) the
| number(s) is normalized and the operand type tag is updated.
-|
+|
| - For a packed number (opclass 2) the number is unpacked and the
| operand type tag is updated.
|
| the '040. The '040 then re-executes the fadd.x fpm,fpn with
| a normalized number in the source and the instruction is
| successful.
-|
+|
| Next consider if in the process of normalizing the un-
| normalized number it becomes a denormalized number. The
| routine which converts the unnorm to a norm (called mk_norm)
| Copyright (C) Motorola, Inc. 1990
| All Rights Reserved
|
-| THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA
-| The copyright notice above does not evidence any
+| THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA
+| The copyright notice above does not evidence any
| actual or intended publication of such source code.
GET_OP: |idnt 2,1 | Motorola 040 Floating Point Software Package
uni_getop:
bfextu CMDREG1B(%a6){#0:#6},%d0 |get opclass and src fields
- cmpil #0x17,%d0 |if op class and size fields are $17,
+ cmpil #0x17,%d0 |if op class and size fields are $17,
| ;it is FMOVECR; if not, continue
|
| If the instruction is fmovecr, exit get_op. It is handled
movew FPTEMP_EX(%a6),%d0 |get destination exponent
andiw #0x7fff,%d0 |mask sign, check if exp = 0000
beqs src_op_ck |if denorm then check source op.
-| ;denorms are taken care of in res_func
+| ;denorms are taken care of in res_func
| ;(unsupp) or do_func (unimp)
| ;else unnorm fall through
leal FPTEMP(%a6),%a0 |point a0 to dop - used in mk_norm
bsr mk_norm |go normalize - mk_norm returns:
-| ;L_SCR1{7:5} = operand tag
+| ;L_SCR1{7:5} = operand tag
| ; (000 = norm, 100 = denorm)
-| ;L_SCR1{4} = fpte15 or ete15
+| ;L_SCR1{4} = fpte15 or ete15
| ; 0 = exp > $3fff
| ; 1 = exp <= $3fff
-| ;and puts the normalized num back
+| ;and puts the normalized num back
| ;on the fsave stack
|
- moveb L_SCR1(%a6),DTAG(%a6) |write the new tag & fpte15
-| ;to the fsave stack and fall
+ moveb L_SCR1(%a6),DTAG(%a6) |write the new tag & fpte15
+| ;to the fsave stack and fall
| ;through to check source operand
|
src_op_ck:
src_ex_dnrm:
movew ETEMP_EX(%a6),%d0 |get source exponent
andiw #0x7fff,%d0 |mask sign, check if exp = 0000
- beq end_getop |if denorm then exit, denorms are
+ beq end_getop |if denorm then exit, denorms are
| ;handled in do_func
leal ETEMP(%a6),%a0 |point a0 to sop - used in mk_norm
bsr mk_norm |go normalize - mk_norm returns:
-| ;L_SCR1{7:5} = operand tag
+| ;L_SCR1{7:5} = operand tag
| ; (000 = norm, 100 = denorm)
-| ;L_SCR1{4} = fpte15 or ete15
+| ;L_SCR1{4} = fpte15 or ete15
| ; 0 = exp > $3fff
| ; 1 = exp <= $3fff
-| ;and puts the normalized num back
+| ;and puts the normalized num back
| ;on the fsave stack
|
- moveb L_SCR1(%a6),STAG(%a6) |write the new tag & ete15
+ moveb L_SCR1(%a6),STAG(%a6) |write the new tag & ete15
rts |end_getop
|
movew #0x3c01,%d1 |write the bias for a dbl denorm
common:
btstb #sign_bit,ETEMP_EX(%a6) |grab sign bit of mantissa
- beqs pos
+ beqs pos
bset #15,%d1 |set sign bit because it is negative
pos:
movew %d1,ETEMP_EX(%a6)
movew %d1,CMDREG1B(%a6) |write back to the command word in stack
| ;this is needed to fix unsupp data stack
leal ETEMP(%a6),%a0 |point a0 to sop
-
+
bsr mk_norm |convert sgl/dbl denorm to norm
moveb L_SCR1(%a6),STAG(%a6) |put tag into source tag reg - d0
rts |end_getop
| instruction is dyadic or monadic is still unknown
|
pack_source:
- movel FPTEMP_LO(%a6),ETEMP(%a6) |write ms part of packed
+ movel FPTEMP_LO(%a6),ETEMP(%a6) |write ms part of packed
| ;number to etemp slot
bsr chk_dy_mo |set dyadic/monadic flag
bsr unpack
btstb #7,DTAG(%a6) |check dest tag for unnorm or denorm
bne dst_ex_dnrm |else, handle the unnorm or ext denorm
|
-| Dest is not denormalized. Check for norm, and set fpte15
+| Dest is not denormalized. Check for norm, and set fpte15
| accordingly.
|
moveb DTAG(%a6),%d0
| unsupported data type exception. Set if dyadic.
|
chk_dy_mo:
- movew CMDREG1B(%a6),%d0
+ movew CMDREG1B(%a6),%d0
btstl #5,%d0 |testing extension command word
beqs set_mon |if bit 5 = 0 then monadic
btstl #4,%d0 |know that bit 5 = 1
beqs set_dya |if bit 4 = 0 then dyadic
andiw #0x007f,%d0 |get rid of all but extension bits {6:0}
- cmpiw #0x0038,%d0 |if extension = $38 then fcmp (dyadic)
+ cmpiw #0x0038,%d0 |if extension = $38 then fcmp (dyadic)
bnes set_mon
set_dya:
st DY_MO_FLG(%a6) |set the inst flag type to dyadic
| L_SCR1{7:5} = operand tag (000 = norm, 100 = denorm)
| L_SCR1{4} = fpte15 or ete15 (0 = exp > $3fff, 1 = exp <=$3fff)
| the normalized operand is placed back on the fsave stack
-mk_norm:
+mk_norm:
clrl L_SCR1(%a6)
bclrb #sign_bit,LOCAL_EX(%a0)
sne LOCAL_SGN(%a0) |transform into internal extended format
cmpw #0x3fff,LOCAL_EX(%a0) |if exp > $3fff
bgts end_mk | fpte15/ete15 already set to 0
bsetb #4,L_SCR1(%a6) |else set fpte15/ete15 to 1
-| ;calling routine actually sets the
-| ;value on the stack (along with the
-| ;tag), since this routine doesn't
+| ;calling routine actually sets the
+| ;value on the stack (along with the
+| ;tag), since this routine doesn't
| ;know if it should set ete15 or fpte15
-| ;ie, it doesn't know if this is the
+| ;ie, it doesn't know if this is the
| ;src op or dest op.
end_mk:
bfclr LOCAL_SGN(%a0){#0:#8}
|
uns_opx:
bsr nrm_zero |normalize the number
- btstb #7,LOCAL_HI(%a0) |check if integer bit (j-bit) is set
+ btstb #7,LOCAL_HI(%a0) |check if integer bit (j-bit) is set
beqs uns_den |if clear then now have a denorm
uns_nrm:
orb #norm_tag,L_SCR1(%a6) |set tag to norm
|
uni_inst:
bsr nrm_zero
- btstb #7,LOCAL_HI(%a0) |check if integer bit (j-bit) is set
+ btstb #7,LOCAL_HI(%a0) |check if integer bit (j-bit) is set
beqs uni_den |if clear then now have a denorm
uni_nrm:
orb #norm_tag,L_SCR1(%a6) |set tag to norm
|
| Decimal to binary conversion
|
-| Special cases of inf and NaNs are completed outside of decbin.
+| Special cases of inf and NaNs are completed outside of decbin.
| If the input is an snan, the snan bit is not set.
-|
+|
| input:
| ETEMP(a6) - points to packed decimal string in memory
| output:
finish:
movew CMDREG1B(%a6),%d0 |get the command word
- andw #0xfbff,%d0 |change the source specifier field to
+ andw #0xfbff,%d0 |change the source specifier field to
| ;extended (was packed).
movew %d0,CMDREG1B(%a6) |write command word back to fsave stack
-| ;we need to do this so the 040 will
-| ;re-execute the inst. without taking
+| ;we need to do this so the 040 will
+| ;re-execute the inst. without taking
| ;another packed trap.
fix_stag:
-|Converted result is now in etemp on fsave stack, now set the source
-|tag (stag)
+|Converted result is now in etemp on fsave stack, now set the source
+|tag (stag)
| if (ete =$7fff) then INF or NAN
| if (etemp = $x.0----0) then
| stag = INF
| stag = NORM
|
| Note also that the etemp_15 bit (just right of the stag) must
-| be set accordingly.
+| be set accordingly.
|
movew ETEMP_EX(%a6),%d1
andiw #0x7fff,%d1 |strip sign
- cmpw #0x7fff,%d1
- bnes z_or_nrm
+ cmpw #0x7fff,%d1
+ bnes z_or_nrm
movel ETEMP_HI(%a6),%d1
bnes is_nan
movel ETEMP_LO(%a6),%d1
movel #0x60,%d0
rts
z_or_nrm:
- tstw %d1
+ tstw %d1
bnes is_nrm
is_zro:
| For a zero, set etemp_15
movel #0,%d0
end_fix:
rts
-
+
end_get:
rts
|end
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