| | |
| | 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 |
