58 lines
1.1 KiB
NASM
58 lines
1.1 KiB
NASM
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cs push \ copy code segment to data segment
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ds pop
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\ print number
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\ in: ax = number
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\ clobbers: ax, cx, dx
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ax 123 # mov
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cx 10 # mov
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:> moredigits
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dx dx xor
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cx div
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dl 48 # add
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ax push
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ax &h0200 # mov
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&h21 int
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ax pop
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moredigits jne
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0 .EXIT
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cx 11 # mov
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\ Register allocation:
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\ ax - top of stack value
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\ ds:di - pointer above second value in stack
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\ ss:sp - return stack pointer
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\ ds:bx - instruction pointer
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\ dx - current instruction (w) - clobberable
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\ interpreter: indirect threaded
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\ dictionary entry layout:
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\ next (w) | charcount (b) | name (b+) | codeptr (w) | args...
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:> @next
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dx [bx] mov
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bx 2 # add
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[dx] jmp
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: .NEXT @next jmp ;
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: lbl>list mkdoer currlbl @ , 0 currlbl !
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does> @ dup execute dlbl execute <: ;
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:> @latest @latest lbl>list latest!
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: outname!
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tell 0 outb!
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0 begin in@ dup [ in@ lit ] != while outb! 1 + repeat drop
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tell >rot swap seek outb! seek ;
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: @mkword latest! outname! ;
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: :asm @mkword tell 2 + tell>addr outw! ;
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:asm ; bx pop .NEXT
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:> $docolon
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bx push
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dx bx mov
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.NEXT
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