diff options
Diffstat (limited to 'arch/m68k/fpsp040/get_op.S')
| -rw-r--r-- | arch/m68k/fpsp040/get_op.S | 676 |
1 files changed, 676 insertions, 0 deletions
diff --git a/arch/m68k/fpsp040/get_op.S b/arch/m68k/fpsp040/get_op.S new file mode 100644 index 00000000000..c7c2f372742 --- /dev/null +++ b/arch/m68k/fpsp040/get_op.S @@ -0,0 +1,676 @@ +| +| get_op.sa 3.6 5/19/92 +| +| get_op.sa 3.5 4/26/91 +| +| Description: This routine is called by the unsupported format/data +| type exception handler ('unsupp' - vector 55) and the unimplemented +| instruction exception handler ('unimp' - vector 11). 'get_op' +| determines the opclass (0, 2, or 3) and branches to the +| opclass handler routine. See 68881/2 User's Manual table 4-11 +| for a description of the opclasses. +| +| For UNSUPPORTED data/format (exception vector 55) and for +| UNIMPLEMENTED instructions (exception vector 11) the following +| applies: +| +| - 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. +| +| - For denormalized numbers (opclass 0 or 2) the number(s) is not +| changed but passed to the next module. The next module for +| unimp is do_func, the next module for unsupp is res_func. +| +| For UNSUPPORTED data/format (exception vector 55) only the +| following applies: +| +| - If there is a move out with a packed number (opclass 3) the +| number is packed and written to user memory. For the other +| opclasses the number(s) are written back to the fsave stack +| and the instruction is then restored back into the '040. The +| '040 is then able to complete the instruction. +| +| For example: +| fadd.x fpm,fpn where the fpm contains an unnormalized number. +| The '040 takes an unsupported data trap and gets to this +| routine. The number is normalized, put back on the stack and +| then an frestore is done to restore the instruction back into +| 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) +| detects this and tags the number as a denorm. The routine +| res_func sees the denorm tag and converts the denorm to a +| norm. The instruction is then restored back into the '040 +| which re_executes the instruction. +| +| +| Copyright (C) Motorola, Inc. 1990 +| All Rights Reserved +| +| 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 + + |section 8 + +#include "fpsp.h" + + .global PIRN,PIRZRM,PIRP + .global SMALRN,SMALRZRM,SMALRP + .global BIGRN,BIGRZRM,BIGRP + +PIRN: + .long 0x40000000,0xc90fdaa2,0x2168c235 |pi +PIRZRM: + .long 0x40000000,0xc90fdaa2,0x2168c234 |pi +PIRP: + .long 0x40000000,0xc90fdaa2,0x2168c235 |pi + +|round to nearest +SMALRN: + .long 0x3ffd0000,0x9a209a84,0xfbcff798 |log10(2) + .long 0x40000000,0xadf85458,0xa2bb4a9a |e + .long 0x3fff0000,0xb8aa3b29,0x5c17f0bc |log2(e) + .long 0x3ffd0000,0xde5bd8a9,0x37287195 |log10(e) + .long 0x00000000,0x00000000,0x00000000 |0.0 +| round to zero;round to negative infinity +SMALRZRM: + .long 0x3ffd0000,0x9a209a84,0xfbcff798 |log10(2) + .long 0x40000000,0xadf85458,0xa2bb4a9a |e + .long 0x3fff0000,0xb8aa3b29,0x5c17f0bb |log2(e) + .long 0x3ffd0000,0xde5bd8a9,0x37287195 |log10(e) + .long 0x00000000,0x00000000,0x00000000 |0.0 +| round to positive infinity +SMALRP: + .long 0x3ffd0000,0x9a209a84,0xfbcff799 |log10(2) + .long 0x40000000,0xadf85458,0xa2bb4a9b |e + .long 0x3fff0000,0xb8aa3b29,0x5c17f0bc |log2(e) + .long 0x3ffd0000,0xde5bd8a9,0x37287195 |log10(e) + .long 0x00000000,0x00000000,0x00000000 |0.0 + +|round to nearest +BIGRN: + .long 0x3ffe0000,0xb17217f7,0xd1cf79ac |ln(2) + .long 0x40000000,0x935d8ddd,0xaaa8ac17 |ln(10) + .long 0x3fff0000,0x80000000,0x00000000 |10 ^ 0 + + .global PTENRN +PTENRN: + .long 0x40020000,0xA0000000,0x00000000 |10 ^ 1 + .long 0x40050000,0xC8000000,0x00000000 |10 ^ 2 + .long 0x400C0000,0x9C400000,0x00000000 |10 ^ 4 + .long 0x40190000,0xBEBC2000,0x00000000 |10 ^ 8 + .long 0x40340000,0x8E1BC9BF,0x04000000 |10 ^ 16 + .long 0x40690000,0x9DC5ADA8,0x2B70B59E |10 ^ 32 + .long 0x40D30000,0xC2781F49,0xFFCFA6D5 |10 ^ 64 + .long 0x41A80000,0x93BA47C9,0x80E98CE0 |10 ^ 128 + .long 0x43510000,0xAA7EEBFB,0x9DF9DE8E |10 ^ 256 + .long 0x46A30000,0xE319A0AE,0xA60E91C7 |10 ^ 512 + .long 0x4D480000,0xC9767586,0x81750C17 |10 ^ 1024 + .long 0x5A920000,0x9E8B3B5D,0xC53D5DE5 |10 ^ 2048 + .long 0x75250000,0xC4605202,0x8A20979B |10 ^ 4096 +|round to minus infinity +BIGRZRM: + .long 0x3ffe0000,0xb17217f7,0xd1cf79ab |ln(2) + .long 0x40000000,0x935d8ddd,0xaaa8ac16 |ln(10) + .long 0x3fff0000,0x80000000,0x00000000 |10 ^ 0 + + .global PTENRM +PTENRM: + .long 0x40020000,0xA0000000,0x00000000 |10 ^ 1 + .long 0x40050000,0xC8000000,0x00000000 |10 ^ 2 + .long 0x400C0000,0x9C400000,0x00000000 |10 ^ 4 + .long 0x40190000,0xBEBC2000,0x00000000 |10 ^ 8 + .long 0x40340000,0x8E1BC9BF,0x04000000 |10 ^ 16 + .long 0x40690000,0x9DC5ADA8,0x2B70B59D |10 ^ 32 + .long 0x40D30000,0xC2781F49,0xFFCFA6D5 |10 ^ 64 + .long 0x41A80000,0x93BA47C9,0x80E98CDF |10 ^ 128 + .long 0x43510000,0xAA7EEBFB,0x9DF9DE8D |10 ^ 256 + .long 0x46A30000,0xE319A0AE,0xA60E91C6 |10 ^ 512 + .long 0x4D480000,0xC9767586,0x81750C17 |10 ^ 1024 + .long 0x5A920000,0x9E8B3B5D,0xC53D5DE5 |10 ^ 2048 + .long 0x75250000,0xC4605202,0x8A20979A |10 ^ 4096 +|round to positive infinity +BIGRP: + .long 0x3ffe0000,0xb17217f7,0xd1cf79ac |ln(2) + .long 0x40000000,0x935d8ddd,0xaaa8ac17 |ln(10) + .long 0x3fff0000,0x80000000,0x00000000 |10 ^ 0 + + .global PTENRP +PTENRP: + .long 0x40020000,0xA0000000,0x00000000 |10 ^ 1 + .long 0x40050000,0xC8000000,0x00000000 |10 ^ 2 + .long 0x400C0000,0x9C400000,0x00000000 |10 ^ 4 + .long 0x40190000,0xBEBC2000,0x00000000 |10 ^ 8 + .long 0x40340000,0x8E1BC9BF,0x04000000 |10 ^ 16 + .long 0x40690000,0x9DC5ADA8,0x2B70B59E |10 ^ 32 + .long 0x40D30000,0xC2781F49,0xFFCFA6D6 |10 ^ 64 + .long 0x41A80000,0x93BA47C9,0x80E98CE0 |10 ^ 128 + .long 0x43510000,0xAA7EEBFB,0x9DF9DE8E |10 ^ 256 + .long 0x46A30000,0xE319A0AE,0xA60E91C7 |10 ^ 512 + .long 0x4D480000,0xC9767586,0x81750C18 |10 ^ 1024 + .long 0x5A920000,0x9E8B3B5D,0xC53D5DE6 |10 ^ 2048 + .long 0x75250000,0xC4605202,0x8A20979B |10 ^ 4096 + + |xref nrm_zero + |xref decbin + |xref round + + .global get_op + .global uns_getop + .global uni_getop +get_op: + clrb DY_MO_FLG(%a6) + tstb UFLG_TMP(%a6) |test flag for unsupp/unimp state + beq uni_getop + +uns_getop: + btstb #direction_bit,CMDREG1B(%a6) + bne opclass3 |branch if a fmove out (any kind) + btstb #6,CMDREG1B(%a6) + beqs uns_notpacked + + bfextu CMDREG1B(%a6){#3:#3},%d0 + cmpb #3,%d0 + beq pack_source |check for a packed src op, branch if so +uns_notpacked: + bsr chk_dy_mo |set the dyadic/monadic flag + tstb DY_MO_FLG(%a6) + beqs src_op_ck |if monadic, go check src op +| ;else, check dst op (fall through) + + btstb #7,DTAG(%a6) + beqs src_op_ck |if dst op is norm, check src op + bras dst_ex_dnrm |else, handle destination unnorm/dnrm + +uni_getop: + 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 +| +| If the instruction is fmovecr, exit get_op. It is handled +| in do_func and smovecr.sa. +| + bne not_fmovecr |handle fmovecr as an unimplemented inst + rts + +not_fmovecr: + btstb #E1,E_BYTE(%a6) |if set, there is a packed operand + bne pack_source |check for packed src op, branch if so + +| The following lines of are coded to optimize on normalized operands + moveb STAG(%a6),%d0 + orb DTAG(%a6),%d0 |check if either of STAG/DTAG msb set + bmis dest_op_ck |if so, some op needs to be fixed + rts + +dest_op_ck: + btstb #7,DTAG(%a6) |check for unsupported data types in + beqs src_op_ck |the destination, if not, check src op + bsr chk_dy_mo |set dyadic/monadic flag + tstb DY_MO_FLG(%a6) | + beqs src_op_ck |if monadic, check src op +| +| At this point, destination has an extended denorm or unnorm. +| +dst_ex_dnrm: + 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 +| ;(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 +| ; (000 = norm, 100 = denorm) +| ;L_SCR1{4} = fpte15 or ete15 +| ; 0 = exp > $3fff +| ; 1 = exp <= $3fff +| ;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 +| ;through to check source operand +| +src_op_ck: + btstb #7,STAG(%a6) + beq end_getop |check for unsupported data types on the +| ;source operand + btstb #5,STAG(%a6) + bnes src_sd_dnrm |if bit 5 set, handle sgl/dbl denorms +| +| At this point only unnorms or extended denorms are possible. +| +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 +| ;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 +| ; (000 = norm, 100 = denorm) +| ;L_SCR1{4} = fpte15 or ete15 +| ; 0 = exp > $3fff +| ; 1 = exp <= $3fff +| ;and puts the normalized num back +| ;on the fsave stack +| + moveb L_SCR1(%a6),STAG(%a6) |write the new tag & ete15 + rts |end_getop + +| +| At this point, only single or double denorms are possible. +| If the inst is not fmove, normalize the source. If it is, +| do nothing to the input. +| +src_sd_dnrm: + btstb #4,CMDREG1B(%a6) |differentiate between sgl/dbl denorm + bnes is_double +is_single: + movew #0x3f81,%d1 |write bias for sgl denorm + bras common |goto the common code +is_double: + movew #0x3c01,%d1 |write the bias for a dbl denorm +common: + btstb #sign_bit,ETEMP_EX(%a6) |grab sign bit of mantissa + beqs pos + bset #15,%d1 |set sign bit because it is negative +pos: + movew %d1,ETEMP_EX(%a6) +| ;put exponent on stack + + movew CMDREG1B(%a6),%d1 + andw #0xe3ff,%d1 |clear out source specifier + orw #0x0800,%d1 |set source specifier to extended prec + 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 +| +| At this point, the source is definitely packed, whether +| instruction is dyadic or monadic is still unknown +| +pack_source: + 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 + + tstb DY_MO_FLG(%a6) + beqs end_getop |if monadic, exit +| ;else, fix FPTEMP +pack_dya: + bfextu CMDREG1B(%a6){#6:#3},%d0 |extract dest fp reg + movel #7,%d1 + subl %d0,%d1 + clrl %d0 + bsetl %d1,%d0 |set up d0 as a dynamic register mask + fmovemx %d0,FPTEMP(%a6) |write to FPTEMP + + 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 +| accordingly. +| + moveb DTAG(%a6),%d0 + andib #0xf0,%d0 |strip to only dtag:fpte15 + tstb %d0 |check for normalized value + bnes end_getop |if inf/nan/zero leave get_op + movew FPTEMP_EX(%a6),%d0 + andiw #0x7fff,%d0 + cmpiw #0x3fff,%d0 |check if fpte15 needs setting + bges end_getop |if >= $3fff, leave fpte15=0 + orb #0x10,DTAG(%a6) + bras end_getop + +| +| At this point, it is either an fmoveout packed, unnorm or denorm +| +opclass3: + clrb DY_MO_FLG(%a6) |set dyadic/monadic flag to monadic + bfextu CMDREG1B(%a6){#4:#2},%d0 + cmpib #3,%d0 + bne src_ex_dnrm |if not equal, must be unnorm or denorm +| ;else it is a packed move out +| ;exit +end_getop: + rts + +| +| Sets the DY_MO_FLG correctly. This is used only on if it is an +| unsupported data type exception. Set if dyadic. +| +chk_dy_mo: + 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) + bnes set_mon +set_dya: + st DY_MO_FLG(%a6) |set the inst flag type to dyadic + rts +set_mon: + clrb DY_MO_FLG(%a6) |set the inst flag type to monadic + rts +| +| MK_NORM +| +| Normalizes unnormalized numbers, sets tag to norm or denorm, sets unfl +| exception if denorm. +| +| CASE opclass 0x0 unsupp +| mk_norm till msb set +| set tag = norm +| +| CASE opclass 0x0 unimp +| mk_norm till msb set or exp = 0 +| if integer bit = 0 +| tag = denorm +| else +| tag = norm +| +| CASE opclass 011 unsupp +| mk_norm till msb set or exp = 0 +| if integer bit = 0 +| tag = denorm +| set unfl_nmcexe = 1 +| else +| tag = norm +| +| if exp <= $3fff +| set ete15 or fpte15 = 1 +| else set ete15 or fpte15 = 0 + +| input: +| a0 = points to operand to be normalized +| output: +| 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: + clrl L_SCR1(%a6) + bclrb #sign_bit,LOCAL_EX(%a0) + sne LOCAL_SGN(%a0) |transform into internal extended format + + cmpib #0x2c,1+EXC_VEC(%a6) |check if unimp + bnes uns_data |branch if unsupp + bsr uni_inst |call if unimp (opclass 0x0) + bras reload +uns_data: + btstb #direction_bit,CMDREG1B(%a6) |check transfer direction + bnes bit_set |branch if set (opclass 011) + bsr uns_opx |call if opclass 0x0 + bras reload +bit_set: + bsr uns_op3 |opclass 011 +reload: + 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 +| ;know if it should set ete15 or fpte15 +| ;ie, it doesn't know if this is the +| ;src op or dest op. +end_mk: + bfclr LOCAL_SGN(%a0){#0:#8} + beqs end_mk_pos + bsetb #sign_bit,LOCAL_EX(%a0) |convert back to IEEE format +end_mk_pos: + rts +| +| CASE opclass 011 unsupp +| +uns_op3: + bsr nrm_zero |normalize till msb = 1 or exp = zero + btstb #7,LOCAL_HI(%a0) |if msb = 1 + bnes no_unfl |then branch +set_unfl: + orw #dnrm_tag,L_SCR1(%a6) |set denorm tag + bsetb #unfl_bit,FPSR_EXCEPT(%a6) |set unfl exception bit +no_unfl: + rts +| +| CASE opclass 0x0 unsupp +| +uns_opx: + bsr nrm_zero |normalize the number + 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 + rts +uns_den: + orb #dnrm_tag,L_SCR1(%a6) |set tag to denorm + rts +| +| CASE opclass 0x0 unimp +| +uni_inst: + bsr nrm_zero + 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 + rts +uni_den: + orb #dnrm_tag,L_SCR1(%a6) |set tag to denorm + rts + +| +| Decimal to binary conversion +| +| 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: +| fp0 - contains packed string converted to extended precision +| ETEMP - same as fp0 +unpack: + movew CMDREG1B(%a6),%d0 |examine command word, looking for fmove's + andw #0x3b,%d0 + beq move_unpack |special handling for fmove: must set FPSR_CC + + movew ETEMP(%a6),%d0 |get word with inf information + bfextu %d0{#20:#12},%d1 |get exponent into d1 + cmpiw #0x0fff,%d1 |test for inf or NaN + bnes try_zero |if not equal, it is not special + bfextu %d0{#17:#3},%d1 |get SE and y bits into d1 + cmpiw #7,%d1 |SE and y bits must be on for special + bnes try_zero |if not on, it is not special +|input is of the special cases of inf and NaN + tstl ETEMP_HI(%a6) |check ms mantissa + bnes fix_nan |if non-zero, it is a NaN + tstl ETEMP_LO(%a6) |check ls mantissa + bnes fix_nan |if non-zero, it is a NaN + bra finish |special already on stack +fix_nan: + btstb #signan_bit,ETEMP_HI(%a6) |test for snan + bne finish + orl #snaniop_mask,USER_FPSR(%a6) |always set snan if it is so + bra finish +try_zero: + movew ETEMP_EX+2(%a6),%d0 |get word 4 + andiw #0x000f,%d0 |clear all but last ni(y)bble + tstw %d0 |check for zero. + bne not_spec + tstl ETEMP_HI(%a6) |check words 3 and 2 + bne not_spec + tstl ETEMP_LO(%a6) |check words 1 and 0 + bne not_spec + tstl ETEMP(%a6) |test sign of the zero + bges pos_zero + movel #0x80000000,ETEMP(%a6) |write neg zero to etemp + clrl ETEMP_HI(%a6) + clrl ETEMP_LO(%a6) + bra finish +pos_zero: + clrl ETEMP(%a6) + clrl ETEMP_HI(%a6) + clrl ETEMP_LO(%a6) + bra finish + +not_spec: + fmovemx %fp0-%fp1,-(%a7) |save fp0 - decbin returns in it + bsr decbin + fmovex %fp0,ETEMP(%a6) |put the unpacked sop in the fsave stack + fmovemx (%a7)+,%fp0-%fp1 + fmovel #0,%FPSR |clr fpsr from decbin + bra finish + +| +| Special handling for packed move in: Same results as all other +| packed cases, but we must set the FPSR condition codes properly. +| +move_unpack: + movew ETEMP(%a6),%d0 |get word with inf information + bfextu %d0{#20:#12},%d1 |get exponent into d1 + cmpiw #0x0fff,%d1 |test for inf or NaN + bnes mtry_zero |if not equal, it is not special + bfextu %d0{#17:#3},%d1 |get SE and y bits into d1 + cmpiw #7,%d1 |SE and y bits must be on for special + bnes mtry_zero |if not on, it is not special +|input is of the special cases of inf and NaN + tstl ETEMP_HI(%a6) |check ms mantissa + bnes mfix_nan |if non-zero, it is a NaN + tstl ETEMP_LO(%a6) |check ls mantissa + bnes mfix_nan |if non-zero, it is a NaN +|input is inf + orl #inf_mask,USER_FPSR(%a6) |set I bit + tstl ETEMP(%a6) |check sign + bge finish + orl #neg_mask,USER_FPSR(%a6) |set N bit + bra finish |special already on stack +mfix_nan: + orl #nan_mask,USER_FPSR(%a6) |set NaN bit + moveb #nan_tag,STAG(%a6) |set stag to NaN + btstb #signan_bit,ETEMP_HI(%a6) |test for snan + bnes mn_snan + orl #snaniop_mask,USER_FPSR(%a6) |set snan bit + btstb #snan_bit,FPCR_ENABLE(%a6) |test for snan enabled + bnes mn_snan + bsetb #signan_bit,ETEMP_HI(%a6) |force snans to qnans +mn_snan: + tstl ETEMP(%a6) |check for sign + bge finish |if clr, go on + orl #neg_mask,USER_FPSR(%a6) |set N bit + bra finish + +mtry_zero: + movew ETEMP_EX+2(%a6),%d0 |get word 4 + andiw #0x000f,%d0 |clear all but last ni(y)bble + tstw %d0 |check for zero. + bnes mnot_spec + tstl ETEMP_HI(%a6) |check words 3 and 2 + bnes mnot_spec + tstl ETEMP_LO(%a6) |check words 1 and 0 + bnes mnot_spec + tstl ETEMP(%a6) |test sign of the zero + bges mpos_zero + orl #neg_mask+z_mask,USER_FPSR(%a6) |set N and Z + movel #0x80000000,ETEMP(%a6) |write neg zero to etemp + clrl ETEMP_HI(%a6) + clrl ETEMP_LO(%a6) + bras finish +mpos_zero: + orl #z_mask,USER_FPSR(%a6) |set Z + clrl ETEMP(%a6) + clrl ETEMP_HI(%a6) + clrl ETEMP_LO(%a6) + bras finish + +mnot_spec: + fmovemx %fp0-%fp1,-(%a7) |save fp0 ,fp1 - decbin returns in fp0 + bsr decbin + fmovex %fp0,ETEMP(%a6) +| ;put the unpacked sop in the fsave stack + fmovemx (%a7)+,%fp0-%fp1 + +finish: + movew CMDREG1B(%a6),%d0 |get the command word + 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 +| ;another packed trap. + +fix_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 +| else +| stag = NAN +| else +| if (ete = $0000) then +| stag = ZERO +| else +| stag = NORM +| +| Note also that the etemp_15 bit (just right of the stag) must +| be set accordingly. +| + movew ETEMP_EX(%a6),%d1 + andiw #0x7fff,%d1 |strip sign + cmpw #0x7fff,%d1 + bnes z_or_nrm + movel ETEMP_HI(%a6),%d1 + bnes is_nan + movel ETEMP_LO(%a6),%d1 + bnes is_nan +is_inf: + moveb #0x40,STAG(%a6) + movel #0x40,%d0 + rts +is_nan: + moveb #0x60,STAG(%a6) + movel #0x60,%d0 + rts +z_or_nrm: + tstw %d1 + bnes is_nrm +is_zro: +| For a zero, set etemp_15 + moveb #0x30,STAG(%a6) + movel #0x20,%d0 + rts +is_nrm: +| For a norm, check if the exp <= $3fff; if so, set etemp_15 + cmpiw #0x3fff,%d1 + bles set_bit15 + moveb #0,STAG(%a6) + bras end_is_nrm +set_bit15: + moveb #0x10,STAG(%a6) +end_is_nrm: + movel #0,%d0 +end_fix: + rts + +end_get: + rts + |end |