23 lines
679 B
Plaintext
23 lines
679 B
Plaintext
// This file is part of www.nand2tetris.org
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// and the book "The Elements of Computing Systems"
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// by Nisan and Schocken, MIT Press.
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// File name: projects/08/ProgramFlow/BasicLoop/BasicLoop.vm
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// Computes the sum 1 + 2 + ... + argument[0] and pushes the
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// result onto the stack. Argument[0] is initialized by the test
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// script before this code starts running.
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push constant 0
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pop local 0 // initializes sum = 0
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label LOOP_START
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push argument 0
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push local 0
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add
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pop local 0 // sum = sum + counter
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push argument 0
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push constant 1
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sub
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pop argument 0 // counter--
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push argument 0
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if-goto LOOP_START // If counter > 0, goto LOOP_START
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push local 0
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