425 lines
5.4 KiB
ArmAsm
425 lines
5.4 KiB
ArmAsm
.define .adf4, .adf8, .sbf4, .sbf8, .mlf4, .mlf8, .dvf4, .dvf8
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.define .ngf4, .ngf8, .fif4, .fif8, .fef4, .fef8
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.define .cif4, .cif8, .cuf4, .cuf8, .cfi, .cfu, .cff4, .cff8
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.define .cmf4, .cmf8
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.sect .text; .sect .rom; .sect .data; .sect .bss
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! $Id$
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! Implement interface to floating point package for Intel 8087
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.sect .rom
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one:
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.data2 1
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two:
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.data2 2
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bigmin:
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.data4 -2147483648
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.sect .text
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.adf4:
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mov bx,sp
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flds 4(bx)
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fadds 8(bx)
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fstps 8(bx)
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wait
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ret
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.adf8:
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mov bx,sp
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fldd 4(bx)
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faddd 12(bx)
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fstpd 12(bx)
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wait
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ret
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.sbf4:
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mov bx,sp
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flds 8(bx)
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fsubs 4(bx)
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fstps 8(bx)
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wait
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ret
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.sbf8:
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mov bx,sp
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fldd 12(bx)
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fsubd 4(bx)
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fstpd 12(bx)
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wait
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ret
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.mlf4:
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mov bx,sp
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flds 4(bx)
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fmuls 8(bx)
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fstps 8(bx)
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wait
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ret
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.mlf8:
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mov bx,sp
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fldd 4(bx)
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fmuld 12(bx)
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fstpd 12(bx)
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wait
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ret
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.dvf4:
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mov bx,sp
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flds 8(bx)
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fdivs 4(bx)
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fstps 8(bx)
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wait
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ret
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.dvf8:
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mov bx,sp
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fldd 12(bx)
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fdivd 4(bx)
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fstpd 12(bx)
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wait
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ret
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.ngf4:
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mov bx,sp
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flds 4(bx)
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fchs
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fstps 4(bx)
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wait
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ret
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.ngf8:
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mov bx,sp
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fldd 4(bx)
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fchs
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fstpd 4(bx)
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wait
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ret
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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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.fif8:
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mov bx,sp
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fldd 8(bx)
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fmuld 16(bx) ! multiply
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fld st ! and 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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fstpd (bx)
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fstpd 8(bx)
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wait
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ret
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.fef4:
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! this could be simpler, if only the
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! fxtract instruction was emulated properly
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mov bx,sp
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mov ax,8(bx)
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and ax,0x7f800000
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je 1f ! zero exponent
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shr ax,23
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sub ax,126
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mov cx,ax ! exponent in cx
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mov ax,8(bx)
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and ax,0x807fffff
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or ax,0x3f000000 ! load -1 exponent
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mov bx,4(bx)
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mov 4(bx),ax
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mov (bx),cx
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ret
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1: ! we get here on zero exp
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mov ax,8(bx)
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and ax,0x007fffff
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jne 1f ! zero result
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mov bx,4(bx)
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mov (bx),ax
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mov 4(bx),ax
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ret
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1: ! otherwise unnormalized number
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mov cx,8(bx)
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and cx,0x807fffff
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mov dx,cx
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and cx,0x80000000
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mov ax,-125
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2:
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test dx,0x800000
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jne 1f
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dec ax
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shl dx,1
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or dx,cx
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jmp 2b
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1:
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mov bx,4(bx)
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mov (bx),ax
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and dx,0x807fffff
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or dx,0x3f000000 ! load -1 exponent
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mov 4(bx),dx
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ret
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.fef8:
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! this could be simpler, if only the
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! fxtract instruction was emulated properly
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mov bx,sp
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mov ax,12(bx)
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and ax,0x7ff00000
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je 1f ! zero exponent
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shr ax,20
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sub ax,1022
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mov cx,ax ! exponent in cx
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mov ax,12(bx)
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and ax,0x800fffff
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or ax,0x3fe00000 ! load -1 exponent
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mov dx,8(bx)
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mov bx,4(bx)
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mov 4(bx),dx
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mov 8(bx),ax
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mov (bx),cx
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ret
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1: ! we get here on zero exp
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mov ax,12(bx)
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and ax,0xfffff
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or ax,8(bx)
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jne 1f ! zero result
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mov bx,4(bx)
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mov (bx),ax
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mov 4(bx),ax
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mov 8(bx),ax
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ret
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1: ! otherwise unnormalized number
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mov cx,12(bx)
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and cx,0x800fffff
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mov dx,cx
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and cx,0x80000000
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mov ax,-1021
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2:
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test dx,0x100000
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jne 1f
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dec ax
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shl 8(bx),1
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rcl dx,1
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or dx,cx
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jmp 2b
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1:
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and dx,0x800fffff
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or dx,0x3fe00000 ! load -1 exponent
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mov cx,8(bx)
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mov bx,4(bx)
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mov (bx),ax
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mov 8(bx),dx
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mov 4(bx),cx
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ret
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.cif4:
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mov bx,sp
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fildl 8(bx)
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fstps 8(bx)
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wait
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ret
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.cif8:
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mov bx,sp
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fildl 8(bx)
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fstpd 4(bx)
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wait
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ret
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.cuf4:
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mov bx,sp
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fildl 8(bx)
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cmp 8(bx),0
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jge 1f
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fisubl (bigmin)
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fisubl (bigmin)
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1:
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fstps 8(bx)
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wait
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ret
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.cuf8:
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mov bx,sp
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fildl 8(bx)
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cmp 8(bx),0
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jge 1f
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fisubl (bigmin)
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fisubl (bigmin)
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1:
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fstpd 4(bx)
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wait
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ret
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.cfi:
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mov bx,sp
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fstcw 4(bx)
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wait
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mov dx,4(bx)
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or 4(bx),0xc00 ! truncating mode
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wait
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fldcw 4(bx)
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cmp 8(bx),4
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jne 2f
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! loc 4 loc ? cfi
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flds 12(bx)
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fistpl 12(bx)
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1:
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mov 4(bx),dx
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wait
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fldcw 4(bx)
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ret
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2:
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! loc 8 loc ? cfi
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fldd 12(bx)
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fistpl 16(bx)
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jmp 1b
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.cfu:
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mov bx,sp
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fstcw 4(bx)
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wait
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mov dx,4(bx)
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and 4(bx),0xf3ff
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or 4(bx),0x400 ! to -infinity
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wait
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fldcw 4(bx)
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cmp 8(bx),4
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jne 2f
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! loc 4 loc ? cfu
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flds 12(bx)
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fabs ! ???
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fiaddl (bigmin)
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fistpl 12(bx)
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wait
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mov ax,12(bx)
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sub ax,(bigmin)
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mov 12(bx),ax
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1:
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mov 4(bx),dx
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wait
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fldcw 4(bx)
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ret
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2:
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! loc 8 loc ? cfu
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fldd 12(bx)
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fabs ! ???
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fiaddl (bigmin)
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fistpl 16(bx)
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wait
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mov ax,16(bx)
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sub ax,(bigmin)
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mov 16(bx),ax
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jmp 1b
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.cff4:
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mov bx,sp
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fldd 4(bx)
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fstcw 4(bx)
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wait
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mov dx,4(bx)
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and 4(bx),0xf3ff ! set to rounding mode
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wait
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fldcw 4(bx)
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fstps 8(bx)
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mov 4(bx),dx
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wait
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fldcw 4(bx)
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wait
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ret
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.cff8:
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mov bx,sp
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flds 4(bx)
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fstpd 4(bx)
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wait
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ret
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.cmf4:
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mov bx,sp
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xor cx,cx
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flds 8(bx)
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flds 4(bx)
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fcompp ! compare and pop operands
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fstsw ax
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wait
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sahf
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je 1f
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jb 2f
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dec cx
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jmp 1f
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2:
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inc cx
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1:
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mov ax,cx
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ret
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.cmf8:
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mov bx,sp
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xor cx,cx
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fldd 12(bx)
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fldd 4(bx)
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fcompp ! compare and pop operands
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fstsw ax
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wait
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sahf
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je 1f
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jb 2f
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dec cx
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jmp 1f
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2:
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inc cx
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1:
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mov ax,cx
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ret
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