256 lines
6.8 KiB
ArmAsm
256 lines
6.8 KiB
ArmAsm
|
|
|
| x_store.sa 3.2 1/24/91
|
|
|
|
|
| store --- store operand to memory or register
|
|
|
|
|
| Used by underflow and overflow handlers.
|
|
|
|
|
| a6 = points to fp value to be stored.
|
|
|
|
|
|
|
| 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.
|
|
|
|
X_STORE: |idnt 2,1 | Motorola 040 Floating Point Software Package
|
|
|
|
|section 8
|
|
|
|
fpreg_mask:
|
|
.byte 0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x01
|
|
|
|
#include "fpsp.h"
|
|
|
|
|xref mem_write
|
|
|xref get_fline
|
|
|xref g_opcls
|
|
|xref g_dfmtou
|
|
|xref reg_dest
|
|
|
|
.global dest_ext
|
|
.global dest_dbl
|
|
.global dest_sgl
|
|
|
|
.global store
|
|
store:
|
|
btstb #E3,E_BYTE(%a6)
|
|
beqs E1_sto
|
|
E3_sto:
|
|
movel CMDREG3B(%a6),%d0
|
|
bfextu %d0{#6:#3},%d0 |isolate dest. reg from cmdreg3b
|
|
sto_fp:
|
|
lea fpreg_mask,%a1
|
|
moveb (%a1,%d0.w),%d0 |convert reg# to dynamic register mask
|
|
tstb LOCAL_SGN(%a0)
|
|
beqs is_pos
|
|
bsetb #sign_bit,LOCAL_EX(%a0)
|
|
is_pos:
|
|
fmovemx (%a0),%d0 |move to correct register
|
|
|
|
|
| if fp0-fp3 is being modified, we must put a copy
|
|
| in the USER_FPn variable on the stack because all exception
|
|
| handlers restore fp0-fp3 from there.
|
|
|
|
|
cmpb #0x80,%d0
|
|
bnes not_fp0
|
|
fmovemx %fp0-%fp0,USER_FP0(%a6)
|
|
rts
|
|
not_fp0:
|
|
cmpb #0x40,%d0
|
|
bnes not_fp1
|
|
fmovemx %fp1-%fp1,USER_FP1(%a6)
|
|
rts
|
|
not_fp1:
|
|
cmpb #0x20,%d0
|
|
bnes not_fp2
|
|
fmovemx %fp2-%fp2,USER_FP2(%a6)
|
|
rts
|
|
not_fp2:
|
|
cmpb #0x10,%d0
|
|
bnes not_fp3
|
|
fmovemx %fp3-%fp3,USER_FP3(%a6)
|
|
rts
|
|
not_fp3:
|
|
rts
|
|
|
|
E1_sto:
|
|
bsrl g_opcls |returns opclass in d0
|
|
cmpib #3,%d0
|
|
beq opc011 |branch if opclass 3
|
|
movel CMDREG1B(%a6),%d0
|
|
bfextu %d0{#6:#3},%d0 |extract destination register
|
|
bras sto_fp
|
|
|
|
opc011:
|
|
bsrl g_dfmtou |returns dest format in d0
|
|
| ;ext=00, sgl=01, dbl=10
|
|
movel %a0,%a1 |save source addr in a1
|
|
movel EXC_EA(%a6),%a0 |get the address
|
|
cmpil #0,%d0 |if dest format is extended
|
|
beq dest_ext |then branch
|
|
cmpil #1,%d0 |if dest format is single
|
|
beq dest_sgl |then branch
|
|
|
|
|
| fall through to dest_dbl
|
|
|
|
|
|
|
|
|
|
| dest_dbl --- write double precision value to user space
|
|
|
|
|
|Input
|
|
| a0 -> destination address
|
|
| a1 -> source in extended precision
|
|
|Output
|
|
| a0 -> destroyed
|
|
| a1 -> destroyed
|
|
| d0 -> 0
|
|
|
|
|
|Changes extended precision to double precision.
|
|
| Note: no attempt is made to round the extended value to double.
|
|
| dbl_sign = ext_sign
|
|
| dbl_exp = ext_exp - $3fff(ext bias) + $7ff(dbl bias)
|
|
| get rid of ext integer bit
|
|
| dbl_mant = ext_mant{62:12}
|
|
|
|
|
| --------------- --------------- ---------------
|
|
| extended -> |s| exp | |1| ms mant | | ls mant |
|
|
| --------------- --------------- ---------------
|
|
| 95 64 63 62 32 31 11 0
|
|
| | |
|
|
| | |
|
|
| | |
|
|
| v v
|
|
| --------------- ---------------
|
|
| double -> |s|exp| mant | | mant |
|
|
| --------------- ---------------
|
|
| 63 51 32 31 0
|
|
|
|
|
dest_dbl:
|
|
clrl %d0 |clear d0
|
|
movew LOCAL_EX(%a1),%d0 |get exponent
|
|
subw #0x3fff,%d0 |subtract extended precision bias
|
|
cmpw #0x4000,%d0 |check if inf
|
|
beqs inf |if so, special case
|
|
addw #0x3ff,%d0 |add double precision bias
|
|
swap %d0 |d0 now in upper word
|
|
lsll #4,%d0 |d0 now in proper place for dbl prec exp
|
|
tstb LOCAL_SGN(%a1)
|
|
beqs get_mant |if positive, go process mantissa
|
|
bsetl #31,%d0 |if negative, put in sign information
|
|
| ; before continuing
|
|
bras get_mant |go process mantissa
|
|
inf:
|
|
movel #0x7ff00000,%d0 |load dbl inf exponent
|
|
clrl LOCAL_HI(%a1) |clear msb
|
|
tstb LOCAL_SGN(%a1)
|
|
beqs dbl_inf |if positive, go ahead and write it
|
|
bsetl #31,%d0 |if negative put in sign information
|
|
dbl_inf:
|
|
movel %d0,LOCAL_EX(%a1) |put the new exp back on the stack
|
|
bras dbl_wrt
|
|
get_mant:
|
|
movel LOCAL_HI(%a1),%d1 |get ms mantissa
|
|
bfextu %d1{#1:#20},%d1 |get upper 20 bits of ms
|
|
orl %d1,%d0 |put these bits in ms word of double
|
|
movel %d0,LOCAL_EX(%a1) |put the new exp back on the stack
|
|
movel LOCAL_HI(%a1),%d1 |get ms mantissa
|
|
movel #21,%d0 |load shift count
|
|
lsll %d0,%d1 |put lower 11 bits in upper bits
|
|
movel %d1,LOCAL_HI(%a1) |build lower lword in memory
|
|
movel LOCAL_LO(%a1),%d1 |get ls mantissa
|
|
bfextu %d1{#0:#21},%d0 |get ls 21 bits of double
|
|
orl %d0,LOCAL_HI(%a1) |put them in double result
|
|
dbl_wrt:
|
|
movel #0x8,%d0 |byte count for double precision number
|
|
exg %a0,%a1 |a0=supervisor source, a1=user dest
|
|
bsrl mem_write |move the number to the user's memory
|
|
rts
|
|
|
|
|
| dest_sgl --- write single precision value to user space
|
|
|
|
|
|Input
|
|
| a0 -> destination address
|
|
| a1 -> source in extended precision
|
|
|
|
|
|Output
|
|
| a0 -> destroyed
|
|
| a1 -> destroyed
|
|
| d0 -> 0
|
|
|
|
|
|Changes extended precision to single precision.
|
|
| sgl_sign = ext_sign
|
|
| sgl_exp = ext_exp - $3fff(ext bias) + $7f(sgl bias)
|
|
| get rid of ext integer bit
|
|
| sgl_mant = ext_mant{62:12}
|
|
|
|
|
| --------------- --------------- ---------------
|
|
| extended -> |s| exp | |1| ms mant | | ls mant |
|
|
| --------------- --------------- ---------------
|
|
| 95 64 63 62 40 32 31 12 0
|
|
| | |
|
|
| | |
|
|
| | |
|
|
| v v
|
|
| ---------------
|
|
| single -> |s|exp| mant |
|
|
| ---------------
|
|
| 31 22 0
|
|
|
|
|
dest_sgl:
|
|
clrl %d0
|
|
movew LOCAL_EX(%a1),%d0 |get exponent
|
|
subw #0x3fff,%d0 |subtract extended precision bias
|
|
cmpw #0x4000,%d0 |check if inf
|
|
beqs sinf |if so, special case
|
|
addw #0x7f,%d0 |add single precision bias
|
|
swap %d0 |put exp in upper word of d0
|
|
lsll #7,%d0 |shift it into single exp bits
|
|
tstb LOCAL_SGN(%a1)
|
|
beqs get_sman |if positive, continue
|
|
bsetl #31,%d0 |if negative, put in sign first
|
|
bras get_sman |get mantissa
|
|
sinf:
|
|
movel #0x7f800000,%d0 |load single inf exp to d0
|
|
tstb LOCAL_SGN(%a1)
|
|
beqs sgl_wrt |if positive, continue
|
|
bsetl #31,%d0 |if negative, put in sign info
|
|
bras sgl_wrt
|
|
|
|
get_sman:
|
|
movel LOCAL_HI(%a1),%d1 |get ms mantissa
|
|
bfextu %d1{#1:#23},%d1 |get upper 23 bits of ms
|
|
orl %d1,%d0 |put these bits in ms word of single
|
|
|
|
sgl_wrt:
|
|
movel %d0,L_SCR1(%a6) |put the new exp back on the stack
|
|
movel #0x4,%d0 |byte count for single precision number
|
|
tstl %a0 |users destination address
|
|
beqs sgl_Dn |destination is a data register
|
|
exg %a0,%a1 |a0=supervisor source, a1=user dest
|
|
leal L_SCR1(%a6),%a0 |point a0 to data
|
|
bsrl mem_write |move the number to the user's memory
|
|
rts
|
|
sgl_Dn:
|
|
bsrl get_fline |returns fline word in d0
|
|
andw #0x7,%d0 |isolate register number
|
|
movel %d0,%d1 |d1 has size:reg formatted for reg_dest
|
|
orl #0x10,%d1 |reg_dest wants size added to reg#
|
|
bral reg_dest |size is X, rts in reg_dest will
|
|
| ;return to caller of dest_sgl
|
|
|
|
dest_ext:
|
|
tstb LOCAL_SGN(%a1) |put back sign into exponent word
|
|
beqs dstx_cont
|
|
bsetb #sign_bit,LOCAL_EX(%a1)
|
|
dstx_cont:
|
|
clrb LOCAL_SGN(%a1) |clear out the sign byte
|
|
|
|
movel #0x0c,%d0 |byte count for extended number
|
|
exg %a0,%a1 |a0=supervisor source, a1=user dest
|
|
bsrl mem_write |move the number to the user's memory
|
|
rts
|
|
|
|
|end
|