Aryadev Chavali
05136fdd25
Name assigned to %CONST is the next symbol in stream, not the symbol attached to it.
93 lines
1.5 KiB
NASM
93 lines
1.5 KiB
NASM
;;; fib.asm: A program that generates the fibonacci numbers up to a
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;;; very large bound (~UINT64_MAX). Using the registers to store the
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;;; pairs of fibonacci numbers, we ensure only a finite amount of
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;;; memory is necessary for this program to function, unlike a pure
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;;; stack version.
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;; Constants
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%const limit 93 %end
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%const increment_i
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push.reg.word 2
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push.word 1
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plus.word
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mov.word 2
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%end
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%const print_i
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push.reg.word 2
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print.word
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%end
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%const print_reg_0
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push.reg.word 0
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print.word
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%end
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%const print_reg_1
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push.reg.word 1
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print.word
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%end
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;; Setup entrypoint
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global main
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main:
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;; Setup iterator I
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push.word 1
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mov.word 2
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;; Setup initial A -> W[0] = 1 and B -> W[1] = 1
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push.word 1
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mov.word 0
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push.word 1
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mov.word 1
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;; Print "$I: $A" and "($I + 1): $B"
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loopback:
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call print_pair
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;; $A += $B
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push.reg.word 0
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push.reg.word 1
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plus.word
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mov.word 0
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;; $B += $A
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push.reg.word 0
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push.reg.word 1
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plus.word
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mov.word 1
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;; IF $I < $LIMIT ...
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push.reg.word 2
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push.word $limit
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lt.word
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;; THEN jump to `loopback`
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jump.if.byte loopback
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;; ELSE halt
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halt
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print_pair:
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push.byte '\t'
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print.char
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$print_i
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push.byte ':'
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print.char
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push.byte ' '
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print.char
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$print_reg_0
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push.byte '\n'
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print.char
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$increment_i
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push.byte '\t'
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print.char
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$print_i
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push.byte ':'
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print.char
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push.byte ' '
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print.char
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$print_reg_1
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push.byte '\n'
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print.char
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$increment_i
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ret
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