diff --git a/regression/test.sh b/regression/test.sh
index 61dca4a12..5cdc61484 100755
--- a/regression/test.sh
+++ b/regression/test.sh
@@ -1,3 +1,4 @@
 make check
 pushd expressions && make check && popd
 pushd deep-expressions && make check && popd
+pushd x86only && make check && popd
diff --git a/regression/x86only/Makefile b/regression/x86only/Makefile
new file mode 100644
index 000000000..d78ca38c1
--- /dev/null
+++ b/regression/x86only/Makefile
@@ -0,0 +1,13 @@
+TESTS=$(basename $(wildcard test*.expr))
+
+RC=../../src/rc.opt
+
+.PHONY: check $(TESTS) 
+
+check: $(TESTS)
+
+$(TESTS): %: %.expr
+	@RC_RUNTIME=../../runtime $(RC) $< && cat $@.input | ./$@ > $@.log && diff $@.log orig/$@.log
+
+clean:
+	rm -f test*.log *.s *~ $(TESTS)
diff --git a/regression/x86only/orig/test001.log b/regression/x86only/orig/test001.log
new file mode 100644
index 000000000..b89fb7132
--- /dev/null
+++ b/regression/x86only/orig/test001.log
@@ -0,0 +1,12 @@
+`Empty
+`Node (0, `Empty, `Empty)
+`Node (0, `Empty, `Node (1, `Empty, `Empty))
+`Node (0, `Empty, `Node (1, `Empty, `Node (2, `Empty, `Empty)))
+`Node (0, `Empty, `Node (1, `Empty, `Node (2, `Empty, `Node (3, `Empty, `Empty))))
+`Node (0, `Empty, `Node (1, `Empty, `Node (2, `Empty, `Node (3, `Empty, `Node (4, `Empty, `Empty)))))
+`Node (0, `Empty, `Node (1, `Empty, `Node (2, `Empty, `Node (3, `Empty, `Node (4, `Empty, `Node (5, `Empty, `Empty))))))
+`Node (0, `Empty, `Node (1, `Empty, `Node (2, `Empty, `Node (3, `Empty, `Node (4, `Empty, `Node (5, `Empty, `Node (6, `Empty, `Empty)))))))
+`Node (0, `Empty, `Node (1, `Empty, `Node (2, `Empty, `Node (3, `Empty, `Node (4, `Empty, `Node (5, `Empty, `Node (6, `Empty, `Node (7, `Empty, `Empty))))))))
+`Node (0, `Empty, `Node (1, `Empty, `Node (2, `Empty, `Node (3, `Empty, `Node (4, `Empty, `Node (5, `Empty, `Node (6, `Empty, `Node (7, `Empty, `Node (8, `Empty, `Empty)))))))))
+`Node (0, `Empty, `Node (1, `Empty, `Node (2, `Empty, `Node (3, `Empty, `Node (4, `Empty, `Node (5, `Empty, `Node (6, `Empty, `Node (7, `Empty, `Node (8, `Empty, `Node (9, `Empty, `Empty))))))))))
+`Node (0, `Empty, `Node (1, `Empty, `Node (2, `Empty, `Node (3, `Empty, `Node (4, `Empty, `Node (5, `Empty, `Node (6, `Empty, `Node (7, `Empty, `Node (8, `Empty, `Node (9, `Empty, `Node (10, `Empty, `Empty)))))))))))
diff --git a/regression/x86only/test001.expr b/regression/x86only/test001.expr
new file mode 100644
index 000000000..486bef831
--- /dev/null
+++ b/regression/x86only/test001.expr
@@ -0,0 +1,19 @@
+fun insert (tree, value) {
+  case tree of
+    `Empty                      -> return `Node (value, `Empty, `Empty)
+  | `Node (x, left, right) ->
+       if x > value
+          then return `Node (x, insert (left, value), right)
+          else return `Node (x, left, insert (right, value))
+       fi
+  esac  
+}
+
+tree := `Empty;
+
+for i := 0, i <= 10, i := i+1 do
+ printf ("%s\n", tree.string);
+ tree := insert (tree, i)
+od;
+
+printf ("%s\n", tree.string)
diff --git a/regression/x86only/test001.input b/regression/x86only/test001.input
new file mode 100644
index 000000000..8b1378917
--- /dev/null
+++ b/regression/x86only/test001.input
@@ -0,0 +1 @@
+