fix off-by-one lam loop (#3081)

diff --git a/src/machine/system_calls.rs b/src/machine/system_calls.rs
index 5eb9a6d2622a70af0fd52f148608fec1c8e964cc..320c0d92380adbeee47e9b90320e7118784f8484 100644 (file)
--- a/src/machine/system_calls.rs
+++ b/src/machine/system_calls.rs
@@ -719,7 +719,7 @@ impl MachineState {
         let mut hare = orig_hare;
         let mut tortoise = hare;
 
-        for _ in 1..lam {
+        for _ in 0..lam {
             hare = step(&self.heap, self.heap[hare]);
         }
 
@@ -743,8 +743,6 @@ impl MachineState {
             brent_st.cycle_step(&self.heap);
         }
 
-        // self.heap.pop_cell();
-
         let target_n = self.store(self.deref(self.registers[1]));
         self.unify_fixnum(
             /* FIXME this is not safe */