38 lines
692 B
ArmAsm
38 lines
692 B
ArmAsm
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.sect .text; .sect .rom; .sect .data; .sect .bss
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.define .fif4
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.sect .text
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.fif4:
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mov bx,sp
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flds 8(bx)
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fmuls 12(bx) ! multiply
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fld st ! copy result
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ftst ! test sign; handle negative separately
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fstsw ax
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wait
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sahf ! result of test in condition codes
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jb 1f
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frndint ! this one rounds (?)
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fcom st(1) ! compare with original; if <=, then OK
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fstsw ax
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wait
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sahf
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jbe 2f
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fisubs (one) ! else subtract 1
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jmp 2f
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1: ! here, negative case
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frndint ! this one rounds (?)
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fcom st(1) ! compare with original; if >=, then OK
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fstsw ax
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wait
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sahf
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jae 2f
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fiadds (one) ! else add 1
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2:
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fsub st(1),st ! subtract integer part
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mov bx,4(bx)
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fstps (bx)
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fstps 4(bx)
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wait
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ret
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