summaryrefslogtreecommitdiff
path: root/projects/08/ProgramFlow/BasicLoop/BasicLoop.vm
diff options
context:
space:
mode:
Diffstat (limited to 'projects/08/ProgramFlow/BasicLoop/BasicLoop.vm')
-rw-r--r--projects/08/ProgramFlow/BasicLoop/BasicLoop.vm22
1 files changed, 22 insertions, 0 deletions
diff --git a/projects/08/ProgramFlow/BasicLoop/BasicLoop.vm b/projects/08/ProgramFlow/BasicLoop/BasicLoop.vm
new file mode 100644
index 0000000..dc5a92f
--- /dev/null
+++ b/projects/08/ProgramFlow/BasicLoop/BasicLoop.vm
@@ -0,0 +1,22 @@
+// This file is part of www.nand2tetris.org
+// and the book "The Elements of Computing Systems"
+// by Nisan and Schocken, MIT Press.
+// File name: projects/08/ProgramFlow/BasicLoop/BasicLoop.vm
+
+// Computes the sum 1 + 2 + ... + argument[0] and pushes the
+// result onto the stack. Argument[0] is initialized by the test
+// script before this code starts running.
+push constant 0
+pop local 0 // initializes sum = 0
+label LOOP_START
+push argument 0
+push local 0
+add
+pop local 0 // sum = sum + counter
+push argument 0
+push constant 1
+sub
+pop argument 0 // counter--
+push argument 0
+if-goto LOOP_START // If counter != 0, goto LOOP_START
+push local 0