[9] | 1 | .define .adf4, .adf8, .sbf4, .sbf8, .mlf4, .mlf8, .dvf4, .dvf8
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| 2 | .define .ngf4, .ngf8, .fif4, .fif8, .fef4, .fef8
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| 3 | .define .cif4, .cif8, .cuf4, .cuf8, .cfi, .cfu, .cff4, .cff8
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| 4 | .define .cmf4, .cmf8
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| 5 | .sect .text; .sect .rom; .sect .data; .sect .bss
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| 6 |
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| 7 | ! $Header: /cvsup/minix/src/lib/i86/em/em_fp8087.s,v 1.1.1.1 2005/04/21 14:56:13 beng Exp $
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| 8 |
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| 9 | ! Implement interface to floating point package for Intel 8087
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| 10 |
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| 11 | .sect .rom
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| 12 | one:
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| 13 | .data2 1
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| 14 | two:
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| 15 | .data2 2
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| 16 | bigmin:
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| 17 | .data2 0, -32768
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| 18 |
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| 19 | .sect .text
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| 20 | .adf4:
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| 21 | mov bx,sp
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| 22 | wait
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| 23 | flds 2(bx)
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| 24 | wait
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| 25 | fadds 6(bx)
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| 26 | wait
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| 27 | fstps 6(bx)
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| 28 | wait
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| 29 | ret
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| 30 | .adf8:
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| 31 | mov bx,sp
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| 32 | wait
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| 33 | fldd 2(bx)
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| 34 | wait
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| 35 | faddd 10(bx)
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| 36 | wait
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| 37 | fstpd 10(bx)
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| 38 | wait
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| 39 | ret
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| 40 |
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| 41 | .sbf4:
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| 42 | mov bx,sp
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| 43 | wait
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| 44 | flds 6(bx)
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| 45 | wait
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| 46 | fsubs 2(bx)
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| 47 | wait
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| 48 | fstps 6(bx)
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| 49 | wait
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| 50 | ret
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| 51 |
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| 52 | .sbf8:
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| 53 | mov bx,sp
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| 54 | wait
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| 55 | fldd 10(bx)
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| 56 | wait
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| 57 | fsubd 2(bx)
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| 58 | wait
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| 59 | fstpd 10(bx)
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| 60 | wait
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| 61 | ret
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| 62 |
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| 63 | .mlf4:
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| 64 | mov bx,sp
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| 65 | wait
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| 66 | flds 2(bx)
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| 67 | wait
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| 68 | fmuls 6(bx)
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| 69 | wait
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| 70 | fstps 6(bx)
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| 71 | wait
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| 72 | ret
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| 73 | .mlf8:
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| 74 | mov bx,sp
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| 75 | wait
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| 76 | fldd 2(bx)
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| 77 | wait
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| 78 | fmuld 10(bx)
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| 79 | wait
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| 80 | fstpd 10(bx)
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| 81 | wait
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| 82 | ret
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| 83 |
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| 84 | .dvf4:
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| 85 | mov bx,sp
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| 86 | wait
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| 87 | flds 6(bx)
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| 88 | wait
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| 89 | fdivs 2(bx)
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| 90 | wait
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| 91 | fstps 6(bx)
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| 92 | wait
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| 93 | ret
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| 94 |
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| 95 | .dvf8:
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| 96 | mov bx,sp
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| 97 | wait
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| 98 | fldd 10(bx)
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| 99 | wait
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| 100 | fdivd 2(bx)
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| 101 | wait
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| 102 | fstpd 10(bx)
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| 103 | wait
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| 104 | ret
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| 105 |
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| 106 | .ngf4:
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| 107 | mov bx,sp
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| 108 | wait
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| 109 | flds 2(bx)
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| 110 | wait
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| 111 | fchs
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| 112 | wait
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| 113 | fstps 2(bx)
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| 114 | wait
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| 115 | ret
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| 116 |
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| 117 | .ngf8:
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| 118 | mov bx,sp
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| 119 | wait
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| 120 | fldd 2(bx)
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| 121 | wait
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| 122 | fchs
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| 123 | wait
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| 124 | fstpd 2(bx)
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| 125 | wait
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| 126 | ret
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| 127 |
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| 128 | .fif4:
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| 129 | mov bx,sp
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| 130 | push bx ! make room for FP status word
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| 131 | wait
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| 132 | flds 4(bx)
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| 133 | wait
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| 134 | fmuls 8(bx) ! multiply
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| 135 | wait
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| 136 | fld st ! copy result
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| 137 | wait
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| 138 | ftst ! test sign; handle negative separately
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| 139 | wait
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| 140 | fstsw -2(bx)
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| 141 | wait
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| 142 | mov ax,-2(bx)
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| 143 | sahf ! result of test in condition codes
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| 144 | jb 1f
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| 145 | frndint ! this one rounds (?)
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| 146 | wait
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| 147 | fcom st(1) ! compare with original; if <=, then OK
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| 148 | wait
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| 149 | fstsw -2(bx)
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| 150 | wait
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| 151 | mov ax,-2(bx)
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| 152 | sahf
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| 153 | jbe 2f
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| 154 | fisubs one ! else subtract 1
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| 155 | wait
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| 156 | jmp 2f
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| 157 | 1: ! here, negative case
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| 158 | frndint ! this one rounds (?)
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| 159 | wait
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| 160 | fcom st(1) ! compare with original; if >=, then OK
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| 161 | wait
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| 162 | fstsw -2(bx)
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| 163 | wait
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| 164 | mov ax,-2(bx)
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| 165 | sahf
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| 166 | jae 2f
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| 167 | fiadds one ! else add 1
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| 168 | wait
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| 169 | 2:
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| 170 | fsub st(1),st ! subtract integer part
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| 171 | wait
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| 172 | mov bx,2(bx)
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| 173 | fstps (bx)
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| 174 | wait
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| 175 | fstps 4(bx)
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| 176 | wait
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| 177 | pop bx
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| 178 | ret
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| 179 |
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| 180 | .fif8:
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| 181 | mov bx,sp
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| 182 | push bx ! make room for FP status word
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| 183 | wait
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| 184 | fldd 4(bx)
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| 185 | wait
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| 186 | fmuld 12(bx) ! multiply
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| 187 | wait
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| 188 | fld st ! and copy result
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| 189 | wait
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| 190 | ftst ! test sign; handle negative separately
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| 191 | wait
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| 192 | fstsw -2(bx)
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| 193 | wait
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| 194 | mov ax,-2(bx)
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| 195 | sahf ! result of test in condition codes
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| 196 | jb 1f
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| 197 | frndint ! this one rounds (?)
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| 198 | wait
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| 199 | fcom st(1) ! compare with original; if <=, then OK
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| 200 | wait
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| 201 | fstsw -2(bx)
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| 202 | wait
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| 203 | mov ax,-2(bx)
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| 204 | sahf
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| 205 | jbe 2f
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| 206 | fisubs one ! else subtract 1
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| 207 | wait
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| 208 | jmp 2f
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| 209 | 1: ! here, negative case
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| 210 | frndint ! this one rounds (?)
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| 211 | wait
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| 212 | fcom st(1) ! compare with original; if >=, then OK
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| 213 | wait
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| 214 | fstsw -2(bx)
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| 215 | wait
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| 216 | mov ax,-2(bx)
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| 217 | sahf
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| 218 | jae 2f
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| 219 | fiadds one ! else add 1
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| 220 | wait
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| 221 | 2:
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| 222 | fsub st(1),st ! subtract integer part
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| 223 | mov bx,2(bx)
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| 224 | fstpd (bx)
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| 225 | wait
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| 226 | fstpd 8(bx)
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| 227 | wait
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| 228 | pop bx
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| 229 | ret
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| 230 |
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| 231 | .fef4:
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| 232 | ! this could be simpler, if only the
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| 233 | ! fxtract instruction was emulated properly
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| 234 | mov bx,sp
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| 235 | mov ax,6(bx)
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| 236 | and ax,#077600
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| 237 | je 1f ! zero exponent
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| 238 | mov cx,#7
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| 239 | shr ax,cl
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| 240 | sub ax,#126
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| 241 | mov cx,ax ! exponent in cx
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| 242 | mov ax,6(bx)
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| 243 | and ax,#0100177
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| 244 | or ax,#0037400 ! load -1 exponent
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| 245 | mov dx,4(bx)
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| 246 | mov bx,2(bx)
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| 247 | mov 4(bx),ax
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| 248 | mov 2(bx),dx
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| 249 | mov (bx),cx
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| 250 | ret
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| 251 | 1: ! we get here on zero exp
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| 252 | mov ax,6(bx)
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| 253 | and ax,#0177
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| 254 | or ax,4(bx)
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| 255 | jne 1f ! zero result
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| 256 | xor ax,ax
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| 257 | mov bx,2(bx)
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| 258 | mov (bx),ax
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| 259 | mov 2(bx),ax
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| 260 | mov 4(bx),ax
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| 261 | ret
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| 262 | 1: ! otherwise unnormalized number
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| 263 | mov cx,6(bx)
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| 264 | and cx,#0100177
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| 265 | mov dx,cx
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| 266 | and cx,#0x8000
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| 267 | mov ax,#-125
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| 268 | 2:
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| 269 | test dx,#0x80
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| 270 | jne 1f
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| 271 | dec ax
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| 272 | shl 4(bx),#1
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| 273 | rcl dx,#1
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| 274 | or dx,cx
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| 275 | jmp 2b
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| 276 | 1:
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| 277 | mov cx,4(bx)
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| 278 | mov bx,2(bx)
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| 279 | mov (bx),ax
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| 280 | mov 2(bx),cx
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| 281 | and dx,#0100177
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| 282 | or dx,#0037400 ! load -1 exponent
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| 283 | mov 4(bx),dx
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| 284 | ret
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| 285 |
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| 286 | .fef8:
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| 287 | ! this could be simpler, if only the
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| 288 | ! fxtract instruction was emulated properly
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| 289 | mov bx,sp
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| 290 | mov ax,10(bx)
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| 291 | and ax,#077760
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| 292 | je 1f ! zero exponent
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| 293 | mov cx,#4
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| 294 | shr ax,cl
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| 295 | sub ax,#1022
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| 296 | mov cx,ax ! exponent in cx
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| 297 | mov ax,10(bx)
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| 298 | and ax,#0100017
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| 299 | or ax,#0037740 ! load -1 exponent
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| 300 | push 8(bx)
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| 301 | push 6(bx)
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| 302 | push 4(bx)
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| 303 | mov bx,2(bx)
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| 304 | pop 2(bx)
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| 305 | pop 4(bx)
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| 306 | pop 6(bx)
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| 307 | mov 8(bx),ax
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| 308 | mov (bx),cx
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| 309 | ret
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| 310 | 1: ! we get here on zero exp
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| 311 | mov ax,10(bx)
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| 312 | and ax,#017
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| 313 | or ax,8(bx)
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| 314 | or ax,6(bx)
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| 315 | or ax,4(bx)
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| 316 | jne 1f ! zero result
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| 317 | xor ax,ax
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| 318 | mov bx,2(bx)
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| 319 | mov (bx),ax
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| 320 | mov 2(bx),ax
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| 321 | mov 4(bx),ax
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| 322 | mov 6(bx),ax
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| 323 | mov 8(bx),ax
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| 324 | ret
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| 325 | 1: ! otherwise unnormalized number
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| 326 | mov cx,10(bx)
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| 327 | and cx,#0100017
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| 328 | mov dx,cx
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| 329 | and cx,#0x8000
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| 330 | mov ax,#-1021
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| 331 | 2:
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| 332 | test dx,#0x10
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| 333 | jne 1f
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| 334 | dec ax
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| 335 | shl 4(bx),#1
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| 336 | rcl 6(bx),#1
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| 337 | rcl 8(bx),#1
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| 338 | rcl dx,#1
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| 339 | or dx,cx
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| 340 | jmp 2b
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| 341 | 1:
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| 342 | and dx,#0100017
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| 343 | or dx,#0037740 ! load -1 exponent
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| 344 | mov cx,8(bx)
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| 345 | push 6(bx)
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| 346 | push 4(bx)
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| 347 | mov bx,2(bx)
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| 348 | mov (bx),ax
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| 349 | mov 8(bx),dx
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| 350 | mov 6(bx),cx
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| 351 | pop 2(bx)
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| 352 | pop 4(bx)
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| 353 | ret
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| 354 |
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| 355 | .cif4:
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| 356 | mov bx,sp
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| 357 | cmp 2(bx),#2
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| 358 | jne 1f
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| 359 | wait
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| 360 | filds 4(bx)
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| 361 | wait
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| 362 | fstps 2(bx)
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| 363 | wait
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| 364 | ret
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| 365 | 1:
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| 366 | wait
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| 367 | fildl 4(bx)
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| 368 | wait
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| 369 | fstps 4(bx)
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| 370 | wait
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| 371 | ret
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| 372 |
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| 373 | .cif8:
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| 374 | mov bx,sp
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| 375 | cmp 2(bx),#2
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| 376 | jne 1f
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| 377 | wait
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| 378 | filds 4(bx)
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| 379 | wait
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| 380 | fstpd 2(bx)
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| 381 | wait
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| 382 | ret
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| 383 | 1:
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| 384 | wait
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| 385 | fildl 4(bx)
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| 386 | wait
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| 387 | fstpd 2(bx)
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| 388 | wait
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| 389 | ret
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| 390 |
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| 391 | .cuf4:
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| 392 | mov bx,sp
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| 393 | cmp 2(bx),#2
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| 394 | jne 1f
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| 395 | mov ax,4(bx)
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| 396 | mov 2(bx),ax
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| 397 | mov 4(bx),#0
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| 398 | wait
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| 399 | fildl 2(bx)
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| 400 | wait
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| 401 | fstps 2(bx)
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| 402 | wait
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| 403 | ret
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| 404 | 1:
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| 405 | wait
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| 406 | fildl 4(bx)
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| 407 | wait
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| 408 | cmp 6(bx),#0
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| 409 | jge 1f
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| 410 | 2:
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| 411 | wait
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| 412 | fisubl bigmin
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| 413 | wait
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| 414 | fisubl bigmin
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| 415 | 1:
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| 416 | wait
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| 417 | fstps 4(bx)
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| 418 | wait
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| 419 | ret
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| 420 |
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| 421 | .cuf8:
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| 422 | mov bx,sp
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| 423 | cmp 2(bx),#2
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| 424 | jne 1f
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| 425 | mov 6(bx),#0
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| 426 | 1:
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| 427 | wait
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| 428 | fildl 4(bx)
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| 429 | wait
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| 430 | cmp 6(bx),#0
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| 431 | jge 1f
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| 432 | 2:
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| 433 | wait
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| 434 | fisubl bigmin
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| 435 | wait
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| 436 | fisubl bigmin
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| 437 | 1:
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| 438 | wait
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| 439 | fstpd 2(bx)
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| 440 | wait
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| 441 | ret
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| 442 |
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| 443 | .cfi:
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| 444 | mov bx,sp
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| 445 | push bx
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| 446 | wait
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| 447 | fstcw -2(bx)
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| 448 | wait
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| 449 | mov dx,-2(bx)
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| 450 | or -2(bx),#0xc00 ! truncating mode
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| 451 | wait
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| 452 | fldcw -2(bx)
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| 453 | pop ax
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| 454 | cmp 4(bx),#4
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| 455 | jne 2f
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| 456 | ! loc 4 loc ? cfi
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| 457 | wait
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| 458 | flds 6(bx)
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| 459 | wait
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| 460 | fistpl 6(bx)
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| 461 | wait
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| 462 | cmp 2(bx),#2
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| 463 | jne 1f
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| 464 | mov ax,6(bx)
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| 465 | 1:
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| 466 | mov 4(bx),dx
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| 467 | wait
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| 468 | fldcw 4(bx)
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| 469 | wait
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| 470 | ret
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| 471 | 2:
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| 472 | ! loc 8 loc ? cfi
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| 473 | wait
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| 474 | fldd 6(bx)
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| 475 | wait
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| 476 | fistpl 10(bx)
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| 477 | wait
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| 478 | cmp 2(bx),#2
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| 479 | jne 1b
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| 480 | mov ax,10(bx)
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| 481 | jmp 1b
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| 482 |
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| 483 | .cfu:
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| 484 | mov bx,sp
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| 485 | push bx
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| 486 | wait
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| 487 | fstcw -2(bx)
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| 488 | wait
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| 489 | mov dx,-2(bx)
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| 490 | and -2(bx),#0xf3ff
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| 491 | or -2(bx),#0x400 ! to -infinity
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| 492 | wait
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| 493 | fldcw -2(bx)
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| 494 | wait
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| 495 | pop ax
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| 496 | cmp 4(bx),#4
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| 497 | jne 2f
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| 498 | ! loc 4 loc ? cfu
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| 499 | flds 6(bx)
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| 500 | wait
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| 501 | fabs ! ???
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| 502 | wait
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| 503 | fiaddl bigmin
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| 504 | fistpl 6(bx)
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| 505 | wait
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| 506 | mov ax,8(bx)
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| 507 | sub ax,bigmin+2
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| 508 | mov 8(bx),ax
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| 509 | cmp 2(bx),#2
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| 510 | jne 1f
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| 511 | mov ax,6(bx)
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| 512 | 1:
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| 513 | mov 4(bx),dx
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| 514 | wait
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| 515 | fldcw 4(bx)
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| 516 | wait
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| 517 | ret
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| 518 | 2:
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| 519 | wait
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| 520 | ! loc 8 loc ? cfu
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| 521 | fldd 6(bx)
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| 522 | wait
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| 523 | fabs ! ???
|
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| 524 | wait
|
---|
| 525 | fiaddl bigmin
|
---|
| 526 | fistpl 10(bx)
|
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| 527 | wait
|
---|
| 528 | mov ax,12(bx)
|
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| 529 | sub ax,bigmin+2
|
---|
| 530 | mov 12(bx),ax
|
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| 531 | cmp 2(bx),#2
|
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| 532 | jne 1b
|
---|
| 533 | mov ax,10(bx)
|
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| 534 | jmp 1b
|
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| 535 |
|
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| 536 | .cff4:
|
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| 537 | mov bx,sp
|
---|
| 538 | wait
|
---|
| 539 | fldd 2(bx)
|
---|
| 540 | wait
|
---|
| 541 | fstcw 2(bx)
|
---|
| 542 | wait
|
---|
| 543 | mov dx,2(bx)
|
---|
| 544 | and 2(bx),#0xf3ff ! set to rounding mode
|
---|
| 545 | wait
|
---|
| 546 | fldcw 2(bx)
|
---|
| 547 | wait
|
---|
| 548 | fstps 6(bx)
|
---|
| 549 | mov 2(bx),dx
|
---|
| 550 | wait
|
---|
| 551 | fldcw 2(bx)
|
---|
| 552 | wait
|
---|
| 553 | ret
|
---|
| 554 |
|
---|
| 555 | .cff8:
|
---|
| 556 | mov bx,sp
|
---|
| 557 | wait
|
---|
| 558 | flds 2(bx)
|
---|
| 559 | wait
|
---|
| 560 | fstpd 2(bx)
|
---|
| 561 | wait
|
---|
| 562 | ret
|
---|
| 563 |
|
---|
| 564 | .cmf4:
|
---|
| 565 | mov bx,sp
|
---|
| 566 | push bx ! room for 8087 status word
|
---|
| 567 | xor cx,cx
|
---|
| 568 | wait
|
---|
| 569 | flds 6(bx)
|
---|
| 570 | wait
|
---|
| 571 | flds 2(bx)
|
---|
| 572 | wait
|
---|
| 573 | fcompp ! compare and pop operands
|
---|
| 574 | wait
|
---|
| 575 | fstsw -2(bx)
|
---|
| 576 | wait
|
---|
| 577 | mov ax,-2(bx)
|
---|
| 578 | sahf
|
---|
| 579 | je 1f
|
---|
| 580 | jb 2f
|
---|
| 581 | dec cx
|
---|
| 582 | jmp 1f
|
---|
| 583 | 2:
|
---|
| 584 | inc cx
|
---|
| 585 | 1:
|
---|
| 586 | mov ax,cx
|
---|
| 587 | pop bx
|
---|
| 588 | ret
|
---|
| 589 |
|
---|
| 590 |
|
---|
| 591 | .cmf8:
|
---|
| 592 | mov bx,sp
|
---|
| 593 | push bx ! room for 8087 status word
|
---|
| 594 | xor cx,cx
|
---|
| 595 | wait
|
---|
| 596 | fldd 10(bx)
|
---|
| 597 | wait
|
---|
| 598 | fldd 2(bx)
|
---|
| 599 | wait
|
---|
| 600 | fcompp ! compare and pop operands
|
---|
| 601 | wait
|
---|
| 602 | fstsw -2(bx)
|
---|
| 603 | wait
|
---|
| 604 | mov ax,-2(bx)
|
---|
| 605 | sahf
|
---|
| 606 | je 1f
|
---|
| 607 | jb 2f
|
---|
| 608 | dec cx
|
---|
| 609 | jmp 1f
|
---|
| 610 | 2:
|
---|
| 611 | inc cx
|
---|
| 612 | 1:
|
---|
| 613 | mov ax,cx
|
---|
| 614 | pop bx
|
---|
| 615 | ret
|
---|