test for PR 6950

From-SVN: r54350

gcc/testsuite/gcc.dg/20020607-1.c

@@ -0,0 +1,40 @@
+/* PR middle-end/6950
+   gcc 3.0.4 mistakenly set lhs.low to 0 at the beginning of the num_eq
+   expansion; it should use a temporary.
+/* { dg-do run } */
+
+typedef struct cpp_num cpp_num;
+struct cpp_num
+{
+  long high;
+  long low;
+  char overflow;
+};
+
+#define num_eq(num1, num2) (num1.low == num2.low && num1.high == num2.high)
+
+static cpp_num
+num_equality_op (lhs, rhs)
+     cpp_num lhs, rhs;
+{
+  lhs.low = num_eq (lhs, rhs);
+  lhs.high = 0;
+  lhs.overflow = 0;
+  return lhs;
+}
+
+int main()
+{
+  cpp_num a = { 1, 2 };
+  cpp_num b = { 3, 4 };
+
+  cpp_num result = num_equality_op (a, b);
+  if (result.low)
+    return 1;
+
+  result = num_equality_op (a, a);
+  if (!result.low)
+    return 2;
+
+  return 0;
+}